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Sample records for sustainable metabolic rate

  1. Maximum rates of sustained metabolic rate in cold-exposed Djungarian hamsters (Phodopus sungorus): the second wind.

    Science.gov (United States)

    Ruf, Thomas; Grafl, Beatrice

    2010-10-01

    Djungarian hamsters (Phodopus sungorus) tolerate short-term exposure to ambient temperatures (T(a)s) down to -70°C, but surprisingly, previously appeared to reach maximum sustainable metabolic rate (SusMR) when kept at T(a)s as high as ≥-2°C. We hypothesized that SusMR in Djungarian hamsters may be affected by the degree of prior cold acclimation and temporal patterns of T(a) changes experienced by the animals, as average T(a) declines. After cold-acclimation at +5°C for 6 weeks, hamsters reached rates of SusMR that were 35% higher than previously determined and were able to maintain positive energy balances down to T(a) -9°C. SusMR was unaffected, however, by whether mean cold load was constant or caused by T(a)s cycling between +3°C and as low as -25°C, at hourly intervals. At mean T (a)s between +3 and -3°C hamsters significantly reduced body mass and energy expenditure, but were able to maintain stable body mass at lower T (a)s (-5 to -9°C). These results indicate that prior cold-acclimation profoundly affects SusMR in hamsters and that body mass regulation may play an integral part in maintaining positive energy balance during cold exposure. Because the degree of instantaneous cold load had no effect on SusMR, we hypothesize that limits to energy turnover in Djungarian hamsters are not determined by the capacity to withstand extreme temperatures (i.e., peripheral limits) but are due to central limitation of energy intake.

  2. Scaling metabolic rate fluctuations

    OpenAIRE

    Labra, Fabio A.; Marquet, Pablo A.; Bozinovic, Francisco

    2007-01-01

    Complex ecological and economic systems show fluctuations in macroscopic quantities such as exchange rates, size of companies or populations that follow non-Gaussian tent-shaped probability distributions of growth rates with power-law decay, which suggests that fluctuations in complex systems may be governed by universal mechanisms, independent of particular details and idiosyncrasies. We propose here that metabolic rate within individual organisms may be considered as an example of an emerge...

  3. Resting vs. active: a meta-analysis of the intra- and inter-specific associations between minimum, sustained, and maximum metabolic rates in vertebrates.

    Science.gov (United States)

    Auer, Sonya K; Killen, Shaun S; Rezende, Enrico L

    2017-09-01

    Variation in aerobic capacity has far reaching consequences for the physiology, ecology, and evolution of vertebrates. Whether at rest or active, animals are constrained to operate within the energetic bounds determined by their minimum (minMR) and sustained or maximum metabolic rates (upperMR). MinMR and upperMR can differ considerably among individuals and species but are often presumed to be mechanistically linked to one another. Specifically, minMR is thought to reflect the idling cost of the machinery needed to support upperMR. However, previous analyses based on limited datasets have come to conflicting conclusions regarding the generality and strength of their association.Here we conduct the first comprehensive assessment of their relationship, based on a large number of published estimates of both the intra-specific ( n  = 176) and inter-specific ( n  = 41) phenotypic correlations between minMR and upperMR, estimated as either exercise-induced maximum metabolic rate (VO 2 max), cold-induced summit metabolic rate (Msum), or daily energy expenditure (DEE).Our meta-analysis shows that there is a general positive association between minMR and upperMR that is shared among vertebrate taxonomic classes. However, there was stronger evidence for intra-specific correlations between minMR and Msum and between minMR and DEE than there was for a correlation between minMR and VO 2 max across different taxa. As expected, inter-specific correlation estimates were consistently higher than intra-specific estimates across all traits and vertebrate classes.An interesting exception to this general trend was observed in mammals, which contrast with birds and exhibit no correlation between minMR and Msum. We speculate that this is due to the evolution and recruitment of brown fat as a thermogenic tissue, which illustrates how some species and lineages might circumvent this seemingly general association.We conclude that, in spite of some variability across taxa and traits, the

  4. Restructuring cities for sustainability: A metabolism approach

    OpenAIRE

    Schremmer, C.; Stead, D.

    2009-01-01

    The FP7-funded SUME project (Sustainable Urban Metabolism for Europe) is focusing on the way how future urban systems can be designed to be consistently less damaging to the environment and particularly to climate change than in the present. Urban development scenarios linked with an agent-based urban metabolism model will try to demonstrate the potential to build and rebuild existing (European) cities in ways which will extract much less of specific energy and material resources from the env...

  5. Restructuring cities for sustainability : A metabolism approach

    NARCIS (Netherlands)

    Schremmer, C.; Stead, D.

    2009-01-01

    The FP7-funded SUME project (Sustainable Urban Metabolism for Europe) is focusing on the way how future urban systems can be designed to be consistently less damaging to the environment and particularly to climate change than in the present. Urban development scenarios linked with an agent-based

  6. Personality, metabolic rate and aerobic capacity.

    Directory of Open Access Journals (Sweden)

    Antonio Terracciano

    Full Text Available Personality traits and cardiorespiratory fitness in older adults are reliable predictors of health and longevity. We examined the association between personality traits and energy expenditure at rest (basal metabolic rate and during normal and maximal sustained walking. Personality traits and oxygen (VO(2 consumption were assessed in 642 participants from the Baltimore Longitudinal Study of Aging. Results indicate that personality traits were mostly unrelated to resting metabolic rate and energy expenditure at normal walking pace. However, those who scored lower on neuroticism (r = -0.12 and higher on extraversion (r = 0.11, openness (r = 0.13, and conscientiousness (r = 0.09 had significantly higher energy expenditure at peak walking pace. In addition to greater aerobic capacity, individuals with a more resilient personality profile walked faster and were more efficient in that they required less energy per meter walked. The associations between personality and energy expenditure were not moderated by age or sex, but were in part explained by the proportion of fat mass. In conclusion, differences in personality may matter the most during more challenging activities that require cardiorespiratory fitness. These findings suggest potential pathways that link personality to health outcomes, such as obesity and longevity.

  7. Personality, metabolic rate and aerobic capacity.

    Science.gov (United States)

    Terracciano, Antonio; Schrack, Jennifer A; Sutin, Angelina R; Chan, Wayne; Simonsick, Eleanor M; Ferrucci, Luigi

    2013-01-01

    Personality traits and cardiorespiratory fitness in older adults are reliable predictors of health and longevity. We examined the association between personality traits and energy expenditure at rest (basal metabolic rate) and during normal and maximal sustained walking. Personality traits and oxygen (VO(2)) consumption were assessed in 642 participants from the Baltimore Longitudinal Study of Aging. Results indicate that personality traits were mostly unrelated to resting metabolic rate and energy expenditure at normal walking pace. However, those who scored lower on neuroticism (r = -0.12) and higher on extraversion (r = 0.11), openness (r = 0.13), and conscientiousness (r = 0.09) had significantly higher energy expenditure at peak walking pace. In addition to greater aerobic capacity, individuals with a more resilient personality profile walked faster and were more efficient in that they required less energy per meter walked. The associations between personality and energy expenditure were not moderated by age or sex, but were in part explained by the proportion of fat mass. In conclusion, differences in personality may matter the most during more challenging activities that require cardiorespiratory fitness. These findings suggest potential pathways that link personality to health outcomes, such as obesity and longevity.

  8. Estimation of Warfighter Resting Metabolic Rate

    Science.gov (United States)

    2005-04-14

    intake and activity (Aschoff and Pohl, 1970). In a constant environment during the follicular phase of the menstrual cycle , women show a circadian...Dubois Formula BMI Body Mass Index VO2max Maximum Rate of Oxygen Uptake 1/min RMR Resting Metabolic Rate kcal/h RMRs Standard Resting Metabolic Rate...60% of VO2max the preceding day) and that there was an almost linear-dose response relationship with no evidence of a threshold. Thompson and Manore

  9. Honeybee flight metabolic rate: does it depend upon air temperature?

    Science.gov (United States)

    Woods, William A; Heinrich, Bernd; Stevenson, Robert D

    2005-03-01

    Differing conclusions have been reached as to how or whether varying heat production has a thermoregulatory function in flying honeybees Apis mellifera. We investigated the effects of air temperature on flight metabolic rate, water loss, wingbeat frequency, body segment temperatures and behavior of honeybees flying in transparent containment outdoors. For periods of voluntary, uninterrupted, self-sustaining flight, metabolic rate was independent of air temperature between 19 and 37 degrees C. Thorax temperatures (T(th)) were very stable, with a slope of thorax temperature on air temperature of 0.18. Evaporative heat loss increased from 51 mW g(-1) at 25 degrees C to 158 mW g(-1) at 37 degrees C and appeared to account for head and abdomen temperature excess falling sharply over the same air temperature range. As air temperature increased from 19 to 37 degrees C, wingbeat frequency showed a slight but significant increase, and metabolic expenditure per wingbeat showed a corresponding slight but significant decrease. Bees spent an average of 52% of the measurement period in flight, with 19 of 78 bees sustaining uninterrupted voluntary flight for periods of >1 min. The fraction of time spent flying declined as air temperature increased. As the fraction of time spent flying decreased, the slope of metabolic rate on air temperature became more steeply negative, and was significant for bees flying less than 80% of the time. In a separate experiment, there was a significant inverse relationship of metabolic rate and air temperature for bees requiring frequent or constant agitation to remain airborne, but no dependence for bees that flew with little or no agitation; bees were less likely to require agitation during outdoor than indoor measurements. A recent hypothesis explaining differences between studies in the slope of flight metabolic rate on air temperature in terms of differences in metabolic capacity and thorax temperature is supported for honeybees in voluntary

  10. Antioxidants, metabolic rate and aging in Drosophila

    Science.gov (United States)

    Miquel, J.; Fleming, J.; Economos, A. C.

    1982-01-01

    The metabolic rate-of-living theory of aging was investigated by determining the effect of several life-prolonging antioxidants on the metabolic rate and life span of Drosophila. The respiration rate of groups of continuously agitated flies was determined in a Gilson respirometer. Vitamin E, 2,4-dinitrophenol, nordihydroguaiaretic acid, and thiazolidine carboxylic acid were employed as antioxidants. Results show that all of these antioxidants reduced the oxygen consumption rate and increased the mean life span, and a significant negative linear correlation was found between the mean life span and the metabolic rate. It is concluded that these findings indicate that some antioxidants may inhibit respiration rate in addition to their protective effect against free radical-induced cellular damage.

  11. Acute hypoxia increases the cerebral metabolic rate

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob

    2016-01-01

    The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance...... imaging techniques were used to measure global cerebral blood flow and the venous oxygen saturation in the sagittal sinus. Global cerebral metabolic rate of oxygen was quantified from cerebral blood flow and arteriovenous oxygen saturation difference. Concentrations of lactate, glutamate, N......-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% (p = 0...

  12. From EcoDesign to Industrial Metabolism: Redefinition of Sustainable Innovation and Competitive Sustainability

    DEFF Research Database (Denmark)

    Taps, Stig B.; Brunø, Thomas Ditlev; Nielsen, Kjeld

    2013-01-01

    Successful enterprises are distinguished by their sustainable development reliant on their ability to learn and develop innovative solutions. Recyclability (material and product design) and recycling (process design) emerge as new paradigm for sustainable competitiveness. The paper makes a critical...... evaluation of the most commonly tools and techniques in use and suggests a redefinition of the concept of EcoDesign by integrating End-of-Life activities to gain industrial metabolism. This approach takes a broader innovation perspective, necessary to construct a sustainable innovation community...

  13. Urban metabolism: Measuring the city's contribution to sustainable development.

    Science.gov (United States)

    Conke, Leonardo S; Ferreira, Tainá L

    2015-07-01

    Urban metabolism refers to the assessment of the amount of resources produced and consumed by urban ecosystems. It has become an important tool to understand how the development of one city causes impacts to the local and regional environment and to support a more sustainable urban design and planning. Therefore, the purpose of this paper was to measure the changes in material and energy use occurred in the city of Curitiba (Brazil) between the years of 2000 and 2010. Results reveal better living conditions and socioeconomic improvements derived from higher resource throughput but without complete disregard to environmental issues. Food intake, water consumption and air emissions remained at similar levels; energy use, construction materials and recycled waste were increased. The paper helps illustrate why it seems more adequate to assess the contribution a city makes to sustainable development than to evaluate if one single city is sustainable or not. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Factors influencing sleeping metabolic rate in infants.

    Science.gov (United States)

    Eccles, M P; Cole, T J; Whitehead, R G

    1989-07-01

    Seven West African infants were studied prospectively from birth to 1 year to investigate factors affecting sleeping metabolic rate (SMR), particularly acute infection. There was no rise in SMR associated with acute infection, after adjustment for the effects of changes in body weight and body temperature. In the case of two illnesses, malaria and 'fever', there were falls in adjusted SMR. It is suggested that these falls can be accounted for by the effects of altered energy intake. Other effects on SMR were in close agreement with previous work.

  15. Sustainability and Risk: Towards a Risk-Based Sustainability Rating for Real Estate Investments

    OpenAIRE

    Erika Meins; Daniel Sager

    2013-01-01

    Purpose - To identify the relative contribution of selected sustainability features to property value risk with the aim of generating a risk-based weighting system for a property sustainability rating.Approach - For a given set of sustainability features, a discounted cash flow (DCF) model is used to derive the weights. The anticipated demand for each sustainability feature is described by three future states of nature. Subjective probability distributions describe the occurrence of the futur...

  16. Energy metabolic rate in breeding avocets Recurvirostra avosetta

    NARCIS (Netherlands)

    Hotker, H; Kolsch, G; Visser, GH

    We measured the field metabolic rates of six incubating Avocets by the doubly-labelled water method in a colony on the North-Frisian Wadden Sea coast in 1994. The Avocets had a mean field metabolic rate of 5.04 W (SD+/-0.33 W), which is only 2.3 times their basal metabolic rate as calculated by the

  17. Sustainability rating as internal challenge for the financial sector

    NARCIS (Netherlands)

    Zoeteman, Bastiaan; Kopp, H.E.

    2016-01-01

    Sustainability rating is rapidly maturing to a level where even the complex concept of sustainable development—including the ecological, sociocultural, and economic pillars and their components, as well as governance aspects such as attitudes—can be objectively described and quantitatively analyzed.

  18. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy.

    NARCIS (Netherlands)

    Fronczek, R.; Overeem, S.; Reijntjes, R.; Lammers, G.J.; Dijk, J.G.M.; Pijl, H.

    2008-01-01

    STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were

  19. Sustainability and Counteracting Factors to Profit Rate Decline

    DEFF Research Database (Denmark)

    Ougaard, Morten

    2014-01-01

    This paper discusses sustainability implications of barriers to growth as specified in the theory of the long-term falling rate of profit but focusing on the counteracting factors (CFs) specified by Marx. These depend much on political processes and are important in state theory for understanding...... which implies a destruction of capital that will counteract the falling rate of profit. This will require sustained political intervention....

  20. Managed Sustainable Development Classification Of Resources And Goods amp Services Calculating Sustainable Growth Rate And The Sustainable Development Index

    Directory of Open Access Journals (Sweden)

    Shubham Saxena

    2017-05-01

    Full Text Available Macro-level manmade problems can often be best solved by understanding and manipulating the economics behind it. The world today is facing genuine problems of scarcity of resources and environmental amp ecological issues in view of intergenerational equity. The paper proposes a new approach of identification and classification of i Resources and ii Goods and services in the context of sustainable development. Every economy has ambitious economic growth aspirations which are often found conflicting with the commitments on natural resource conservation and climate change obligations. The proposed methodology is a reconciliation of the aspired economic growth of a region and the conservation of the resources and nature. The paper employs contribution of different types of goods and services in the gross domestic product GDP of a region to analyze sustainability of development. The important parameters that the paper establishes are Sustainability Ratio R Sustainable Growth Rate SG and the Sustainable Development Index SI. These parameters can be used to compare the sustainable development level of different regions. Ensuring natural resource and environmental sustainability will eventually ensure economic sustainability. The paper considers resource depletion concerns as well as the environmental pollutants biological risks carbon footprint warhead proliferation et cetera thereby ensuring all round sustainability from survival to economic end. The sustainability analysis is done for long periods such as 50 years 100 years et cetera. The index shows how sustainable the development of an economy is and how sustainability it is growing. The presently much revered GDP growth numbers are directionless it does not tell the type of growth an economy essentially has. The direction should be sustainability which the paper stresses upon. An illustration of sustainability analysis of India is also done. Such indices can help identifying sustainably developing

  1. Honeybee flight metabolic rate: does it depend upon air temperature?

    National Research Council Canada - National Science Library

    Woods, William A; Heinrich, Bernd; Stevenson, Robert D

    2005-01-01

    .... We investigated the effects of air temperature on flight metabolic rate, water loss, wingbeat frequency, body segment temperatures and behavior of honeybees flying in transparent containment outdoors...

  2. Sleep-Dependent Modulation of Metabolic Rate in Drosophila.

    Science.gov (United States)

    Stahl, Bethany A; Slocumb, Melissa E; Chaitin, Hersh; DiAngelo, Justin R; Keene, Alex C

    2017-08-01

    Dysregulation of sleep is associated with metabolic diseases, and metabolic rate (MR) is acutely regulated by sleep-wake behavior. In humans and rodent models, sleep loss is associated with obesity, reduced metabolic rate, and negative energy balance, yet little is known about the neural mechanisms governing interactions between sleep and metabolism. We have developed a system to simultaneously measure sleep and MR in individual Drosophila, allowing for interrogation of neural systems governing interactions between sleep and metabolic rate. Like mammals, MR in flies is reduced during sleep and increased during sleep deprivation suggesting sleep-dependent regulation of MR is conserved across phyla. The reduction of MR during sleep is not simply a consequence of inactivity because MR is reduced ~30 minutes following the onset of sleep, raising the possibility that CO2 production provides a metric to distinguish different sleep states in the fruit fly. To examine the relationship between sleep and metabolism, we determined basal and sleep-dependent changes in MR is reduced in starved flies, suggesting that starvation inhibits normal sleep-associated effects on metabolic rate. Further, translin mutant flies that fail to suppress sleep during starvation demonstrate a lower basal metabolic rate, but this rate was further reduced in response to starvation, revealing that regulation of starvation-induced changes in MR and sleep duration are genetically distinct. Therefore, this system provides the unique ability to simultaneously measure sleep and oxidative metabolism, providing novel insight into the physiological changes associated with sleep and wakefulness in the fruit fly.

  3. Effects of growth hormone transgenesis on metabolic rate, exercise performance and hypoxia tolerance in tilapia hybrids

    DEFF Research Database (Denmark)

    McKenzie, DJ; Martinez, R; Morales, A

    2003-01-01

    Swimming respirometry was employed to compare inactive metabolic rate (Rr), maximum metabolic rate (Rmax), resultant aerobic scope and maximum sustainable (critical) swimming speed (Ucrit), in growth hormone transgenic (GHT) and wild-type (W) tilapia Oreochromis sp. hybrids. Although the Rr of GHT...... tilapia was significantly (58%) higher than their W conspecifics, there were no significant differences in their net aerobic scope because GHT tilapia exhibited a compensatory increase in Rmax that was equal to their net increase in Rr. As a consequence, the two groups had the same Ucrit. The GHT and W...... tilapia also exhibited the same capacity to regulate oxygen uptake during progressive hypoxia, despite the fact that the GHT fish were defending a higher demand for O2. The results indicate that ectopic expression of GH raises metabolic rate in tilapia, but the fish compensate for this metabolic load...

  4. Comparison of the subjective sense of high or low metabolism and objectively measured resting metabolic rate.

    Science.gov (United States)

    Wallhuss, Andreas; Isik, Markus; Nystrom, Fredrik H

    2010-09-01

    To measure caloric intake, physical activity level and resting metabolic rate in participants having the subjective opinion of either having a high or low metabolic rate. Recruitment by local advertising of healthy subjects feeling that they have high or low metabolism, i.e. either a tendency to easily stay lean ('high') or to very easily gain weight ('low') also when taking food intake in comparison with physical activity into account. Walking distance was estimated by pedometry, assessment of caloric intake was determined by food registration. Measurement of resting metabolic rate was performed in the fasting state. We recruited 44 participants with a sense of 'high' metabolism and 12 subjects in the contrasting group. Subjects with 'high' metabolism were leaner ('high': 20.4 +/- 2.1 kg/m(2), 'low': 27.8 +/- 7.5 kg/m(2), p difference in the measured resting metabolic rate between the two groups ('high': 7230 +/- 1233 kJ/24 h, 'low': 7430 +/- 1422 kJ/24 h, p = 0.6), nor was there any difference in physical activity measured by pedometry. Resting metabolic rate was negatively correlated with age and positively correlated with BMI in multivariate analyses of the total cohort. The sense of having a low or high metabolic rate is not related to actual resting metabolic rate.

  5. A strong response to selection on mass-independent maximal metabolic rate without a correlated response in basal metabolic rate

    DEFF Research Database (Denmark)

    Wone, B W M; Madsen, Per; Donovan, E R

    2015-01-01

    Metabolic rates are correlated with many aspects of ecology, but how selection on different aspects of metabolic rates affects their mutual evolution is poorly understood. Using laboratory mice, we artificially selected for high maximal mass-independent metabolic rate (MMR) without direct selection...... on mass-independent basal metabolic rate (BMR). Then we tested for responses to selection in MMR and correlated responses to selection in BMR. In other lines, we antagonistically selected for mice with a combination of high mass-independent MMR and low mass-independent BMR. All selection protocols...... and data analyses included body mass as a covariate, so effects of selection on the metabolic rates are mass adjusted (that is, independent of effects of body mass). The selection lasted eight generations. Compared with controls, MMR was significantly higher (11.2%) in lines selected for increased MMR...

  6. Auxin metabolism rates and implications for plant development

    Directory of Open Access Journals (Sweden)

    Eric M Kramer

    2015-03-01

    Full Text Available Studies of auxin metabolism rarely express their results as a metabolic rate, although the data obtained would often permit such a calculation to be made. We analyze data from 31 previously published papers to quantify the rates of auxin biosynthesis, conjugation, conjugate hydrolysis, and catabolism in seed plants. Most metabolic pathways have rates in the range 10 nM/h to 1 μM/h, with the exception of auxin conjugation, which has rates as high as ~100 μM/h. The highest rates of auxin conjugation suggests that auxin metabolic sinks may be very small, perhaps as small as a single cell. By contrast, the relatively low rate of auxin biosynthesis requires plants to conserve and recycle auxin during long-distance transport. The consequences for plant development are discussed.

  7. Sustaining without Changing: The Metabolic Rift of Certified Organic Farming

    Directory of Open Access Journals (Sweden)

    Julius Alexander McGee

    2016-01-01

    Full Text Available Many proponents of organic farming claim that it is a sustainable alternative to conventional agriculture due to its reliance on natural agro-inputs, such as manure based fertilizers and organic pesticides. However, in this analysis we argue that although particular organic farming practices clearly benefit ecosystems and human consumers, the social context in which some organic farms develop, limit the potential environmental benefits of organic agriculture. Specifically, we argue that certified organic farming’s increased reliance on agro-inputs, such as organic fertilizers and pesticides, reduces its ability to decrease global water pollution. We review recent research that demonstrates the environmental consequences of specific organic practices, as well as literature showing that global organic farming is increasing its reliance on agro-inputs, and contend that organic farming has its own metabolic rift with natural water systems similar to conventional agriculture. We use a fixed-effects panel regression model to explore how recent rises in certified organic farmland correlate to water pollution (measured as biochemical oxygen demand. Our findings indicate that increases in the proportion of organic farmland over time increases water pollution. We conclude that this may be a result of organic farms increasing their reliance on non-farm agro-inputs, such as fertilizers.

  8. Evaluation of the metabolic rate based on the recording of the heart rate.

    Science.gov (United States)

    Malchaire, Jacques; d'AMBROSIO Alfano, Francesca Romana; Palella, Boris Igor

    2017-06-08

    The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the metabolic rate at rest and the relation (HR vs. M) at the basis of the estimation of the equivalent metabolic rate, as a function of the age, height and weight of the person. A Monte Carlo simulation is used to determine, from the approximations of these parameters and formulas, the imprecision of the estimated equivalent metabolic rate. The results show that the standard deviation of this estimate varies from 10 to 15%.

  9. Variability of Lekanesphaera monodi metabolic rates with habitat trophic status

    Science.gov (United States)

    Vignes, Fabio; Fedele, Marialaura; Pinna, Maurizio; Mancinelli, Giorgio; Basset, Alberto

    2012-05-01

    Regulation of metabolism is a common strategy used by individuals to respond to a changing environment. The mechanisms underlying the variability of metabolic rates in macroinvertebrates are of primary importance in studying benthic-pelagic energy transfer in transitional water ecosystems. Lekanesphaera monodi is an isopod endemic to transitional water ecosystems that can modify its metabolic rate in response to environmental changes. Therefore it is a useful model in studying the influence of environmental factors on metabolism. This study focused on the interpopulation variability of standard metabolic rates (SMR) in L. monodi populations sampled in three transitional water ecosystems differing in their trophic status. The standard metabolic rates of L. monodi individuals across the same range of body size spectra were inferred from oxygen consumption measurements in a flow-through respirometer in the three populations and a body condition index was assessed for each population. Habitat trophic status was evaluated by monthly measurement of the basic physical-chemical parameters of the water column in the ecosystems for one year. Standard metabolic rates showed high variability, ranging from 0.27 to 10.14 J d-1. Body size accounted for more than 38% of total variability. In terms of trophic status, individuals from the eutrophic ecosystem had significantly higher standard metabolic rates than individuals from the other ecosystems (SMR = 2.3 J d-1 in Spunderati Sud vs. 1.36 J d-1 in Alimini and 0.69 J d-1 in Acquatina). The body conditions index was also higher in the population from the eutrophic ecosystem. Results show that standard metabolic rates and growth rates are directly related to habitat productivity in accordance with the expectations of the food habits hypothesis. A possible extension of this hypothesis to benthic invertebrates is proposed.

  10. Metabolic rate regulates L1 longevity in C. elegans.

    Directory of Open Access Journals (Sweden)

    Inhwan Lee

    Full Text Available Animals have to cope with starvation. The molecular mechanisms by which animals survive long-term starvation, however, are not clearly understood. When they hatch without food, C. elegans arrests development at the first larval stage (L1 and survives more than two weeks. Here we show that the survival span of arrested L1s, which we call L1 longevity, is a starvation response regulated by metabolic rate during starvation. A high rate of metabolism shortens the L1 survival span, whereas a low rate of metabolism lengthens it. The longer worms are starved, the slower they grow once they are fed, suggesting that L1 arrest has metabolic costs. Furthermore, mutants of genes that regulate metabolism show altered L1 longevity. Among them, we found that AMP-dependent protein kinase (AMPK, as a key energy sensor, regulates L1 longevity by regulating this metabolic arrest. Our results suggest that L1 longevity is determined by metabolic rate and that AMPK as a master regulator of metabolism controls this arrest so that the animals survive long-term starvation.

  11. Heart rate recovery time in metabolically healthy and metabolically unhealthy obese children.

    Science.gov (United States)

    Bjelakovic, Ljiljana; Vukovic, Vladimir; Jovic, Marko; Bankovic, Sanja; Kostic, Tomislav; Radovanovic, Dragan; Pantelic, Sasa; Zivkovic, Mladen; Stojanovic, Sanja; Bjelakovic, Bojko

    2017-11-01

    Autonomic dysfunction is an emerging non-traditional cardiovascular risk factor that correlates with obesity, components of metabolic syndrome, as well as cardiorespiratory fitness. As a simple and validated index of autonomic balance, heart rate recovery (HRR) has been reported as a useful biomarker for predicting cardiovascular morbidity and mortality. The aim of this study was to compare HRR in metabolically healthy vs. metabolically unhealthy obese children. A total of 56 obese children of whom 31 had metabolic syndrome were examined. All the participants underwent the multistage submaximal cycle ergometer test and HRR was determined one minute after the test. The HRR was significantly lower (18.9 ± 3.7) in a group of metabolically unhealthy obese children compared to metabolically healthy obese children (24 ± 4.1) p heart rate recovery (HRR) in obese children with metabolic syndrome.

  12. The repeatability of metabolic rate declines with time.

    Science.gov (United States)

    White, Craig R; Schimpf, Natalie G; Cassey, Phillip

    2013-05-15

    The evolutionary causes of variation in metabolic rate within and among species are a topic of enduring interest. Variation between individuals is the raw material on which natural selection acts, and so recent years have seen an increase in the number of studies that examine the consequences of inter-individual differences in metabolic rate for organismal performance. A minimum requirement for a trait to evolve is that it must differ consistently between individuals, and these differences must be heritable. The time constancy of a trait is assessed by estimating its repeatability, which represents the ratio of the between-individual component of phenotypic variance to total phenotypic variance. A previous meta-analysis of repeatability concluded that metabolic rate is, on average, repeatable. Here, we expand on this earlier analysis by including extra data published in the intervening years and demonstrate that the repeatability of metabolic rate decreases as the interval between measurements increases.

  13. Is metabolic rate a universal 'pacemaker' for biological processes?

    Science.gov (United States)

    Glazier, Douglas S

    2015-05-01

    A common, long-held belief is that metabolic rate drives the rates of various biological, ecological and evolutionary processes. Although this metabolic pacemaker view (as assumed by the recent, influential 'metabolic theory of ecology') may be true in at least some situations (e.g. those involving moderate temperature effects or physiological processes closely linked to metabolism, such as heartbeat and breathing rate), it suffers from several major limitations, including: (i) it is supported chiefly by indirect, correlational evidence (e.g. similarities between the body-size and temperature scaling of metabolic rate and that of other biological processes, which are not always observed) - direct, mechanistic or experimental support is scarce and much needed; (ii) it is contradicted by abundant evidence showing that various intrinsic and extrinsic factors (e.g. hormonal action and temperature changes) can dissociate the rates of metabolism, growth, development and other biological processes; (iii) there are many examples where metabolic rate appears to respond to, rather than drive the rates of various other biological processes (e.g. ontogenetic growth, food intake and locomotor activity); (iv) there are additional examples where metabolic rate appears to be unrelated to the rate of a biological process (e.g. ageing, circadian rhythms, and molecular evolution); and (v) the theoretical foundation for the metabolic pacemaker view focuses only on the energetic control of biological processes, while ignoring the importance of informational control, as mediated by various genetic, cellular, and neuroendocrine regulatory systems. I argue that a comprehensive understanding of the pace of life must include how biological activities depend on both energy and information and their environmentally sensitive interaction. This conclusion is supported by extensive evidence showing that hormones and other regulatory factors and signalling systems coordinate the processes of

  14. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    Science.gov (United States)

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued. PMID:27828977

  15. Dinosaur Metabolism and the Allometry of Maximum Growth Rate.

    Science.gov (United States)

    Myhrvold, Nathan P

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued.

  16. A low-carbohydrate survey: Evidence for sustainable metabolic syndrome reversal

    Directory of Open Access Journals (Sweden)

    Mark T. Cucuzzella

    2017-12-01

    Full Text Available Background: Metabolic syndrome has become a significant problem, with the American Diabetes Association estimating the cost of diabetes and pre-diabetes in the United States alone to be $322 billion per year. Numerous clinical trials have demonstrated the efficacy of low-carbohydrate diets in reversing metabolic syndrome and its associated disorders. Aim: This study was designed to examine how voluntary adherents to a low-carbohydrate diet rate its effectiveness and sustainability using an online survey. Setting and methods: The 57-question survey was administered online and shared internationally via social media and ‘low-carb’ communities. Where appropriate, chi-squared tests and paired t-tests were used to analyse the responses. Results: There were 1580 respondents. The majority of respondents had consumed less than 100 g of carbohydrates per day for over a year, typically for reasons of weight loss or disease management. There was a reported decrease in waist circumference and weight with a simultaneous decrease in hunger and increase in energy level. Of those who provided laboratory values, the majority saw improvements in their HbA1c, blood glucose measurements, and lipid panel results. There was a reduction in usage of various medications, and 25% reported medication cost savings, with average monthly savings of $288 for those respondents. In particular, the usage of pain relievers and anti-inflammatories dropped with a simultaneous decreased rating of pain and increase in mobility. Conclusion: We conclude that low-carbohydrate diets are a sustainable method of metabolic syndrome reversal in a community setting.

  17. Effect of Cold Water Immersion on Metabolic Rate in Humans

    Directory of Open Access Journals (Sweden)

    Austin Greenwood

    2017-04-01

    Full Text Available Background: Cold water immersion is a widely used form of cryotherapy in the active population despite the limited knowledge on its physiological effects. From an injury standpoint, reducing metabolic rate is advantageous to prevent secondary injury. In contrast, increased metabolism can be beneficial in ridding the body of unwanted metabolites. This study looked to determine the effect of cold water immersion on metabolic rate.  Understanding this phenomenon will help determine appropriate clinical applications of cold water immersion and lead to a better understanding of cryotherapy in general. This study looked to determine the effect of cryotherapy in the form of waist deep cold water immersion at 9° C on metabolic rate. Methods: 10 participants from a university student population volunteered and completed a 15-minute treatment of waist deep cold water (9° C immersion. Metabolic rate measurements were taken using a Jaeger Oxycon Mobile Unit for 5 minutes prior to treatment, 15 minutes of treatment, and 5 minutes post treatment for a total of 25 minutes. Statistical analysis was completed using a one way repeated measures ANOVA test to compare treatment intervals to baseline intervals. Results: Cold water immersion resulted in elevated metabolic rates for 8 of 10 participants during the first 5 minutes of treatment and for 6 of 10 in the 5 minute post treatment (p < 0.05. A second statistical analysis excluding the first 30 second data point in the 5-10 and 20-25 minute treatments was used to account for movement in and out of the whirlpool. The second analysis showed the same results as the first with the exception of one participant who no longer displayed a statistically significant change in the 20-25 minute interval. Conclusion: These results indicate that cold water immersion should not be used as a measure of reducing secondary injury because of its potential to increase metabolic rate, but instead may have potential benefits in

  18. Larval developmental rate, metabolic rate and future growth performance in Atlantic salmon

    DEFF Research Database (Denmark)

    Serrano, Jonathan Vaz; Åberg, Madelene; Gjoen, Hans Magnus

    2009-01-01

    Previous studies in salmonids suggest a link between larval developmental rate, metabolic rate, and future growth. However, the connection between growth during exogenous and endogenous feeding is still debated. In the current study, a positive relationship between larval developmental rate, quan...... and growth in commercial rearing of Atlantic salmon. Furthermore, the link between larval standard metabolic rate and developmental rate and future growth is discussed in the present study.......Previous studies in salmonids suggest a link between larval developmental rate, metabolic rate, and future growth. However, the connection between growth during exogenous and endogenous feeding is still debated. In the current study, a positive relationship between larval developmental rate......, quantified as time to first feeding, and growth in later stages was demonstrated in Atlantic salmon (Salmo salar L.). The observed relationship between future growth and larval developmental rate suggests that sorting larvae by time to first feeding can be a potential tool to optimize feeding strategies...

  19. Hydration status after exercise affect resting metabolic rate and heart rate variability.

    Science.gov (United States)

    Castro-Sepulveda, Mauricio; Cerda-Kohler, Hugo; Pérez-Luco, Cristian; Monsalves, Matías; Andrade, David Cristobal; Zbinden-Foncea, Herman; Báez-San Martín, Eduardo; Ramírez-Campillo, Rodrigo

    2014-12-17

    Heart rate variability and resting metabolic rate are commonly to assess athlete's physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human's homeostasis. To compare the effects of dehydration and rehydration after exercise on heart rate variability and resting metabolic rate in college athletes. 14 college athletes were divided into a dehydration group (n=7) and a rehydration group (n=7), both submitted to basal (T1) heart rate variability and resting metabolic rate measurements. After basal measurements both groups were actively dehydrated (-3.4 ± 0.4% of body mass for both groups). Afterwards, dehydration group rested, while rehydration group receive a fluid intake (during a 3 h period) equivalent to 150% of body mass loss achieved during active dehydration. Four hours after active dehydration heart rate variability and resting metabolic rate were re-assessed (T2). At T2 both rehydration group (+13%) and dehydration group (+30%) achieve a significant (phydration state before resting metabolic rate and heart rate variability assessment. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  20. Evaluation of the metabolic rate based on the recording of the heart rate

    OpenAIRE

    MALCHAIRE, Jacques; ALFANO, Francesca Romana d?AMBROSIO; PALELLA, Boris Igor

    2017-01-01

    The assessment of harsh working conditions requires a correct evaluation of the metabolic rate. This paper revises the basis described in the ISO 8996 standard for the evaluation of the metabolic rate at a work station from the recording of the heart rate of a worker during a representative period of time. From a review of the literature, formulas different from those given in the standard are proposed to estimate the maximum working capacity, the maximum heart rate, the heart rate and the me...

  1. molecular mechanisms of metabolic rate depression in animals

    African Journals Online (AJOL)

    55-4. Survival under stress: molecular mechanisms of metabolic rate depression in animals. Kenneth B. Storey. Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, Ottawa, Ontario, Canada K1S 5B6. E-mail: kbstorey@ccs.earleton.ea. Received 1 September 1997; accepted 4 March J 998.

  2. Basal Metabolic Rate and Energy Expenditure of Rural Farmers in ...

    African Journals Online (AJOL)

    BRIAN

    2013-09-04

    Sep 4, 2013 ... Measurement of basal metabolic rate (BMR) provides an important baseline for the determination of an individual's total energy requirement. The study sought to establish human energy expenditure of rural farmers in Magubike village in Tanzania, through determination of BMR, physical activity level (PAL) ...

  3. Evaluation of methods for estimating the metabolic rate according to ...

    African Journals Online (AJOL)

    A study was made in North Eastern Zimbabwe during the hot season to evaluate ISO standard methods for heat stress risk determination in manual forestry work. The differences between the metabolic rate assessments by three methods of ISO 8996 were evaluated, as well as the effects of these variations in the ...

  4. Dopamine modulates metabolic rate and temperature sensitivity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Taro Ueno

    Full Text Available Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shi(ts induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine, which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation.

  5. Basal Metabolic Rate and Energy Expenditure of Rural Farmers in ...

    African Journals Online (AJOL)

    Measurement of basal metabolic rate (BMR) provides an important baseline for the determination of an individual's total energy requirement. The study sought to establish human energy expenditure of rural farmers in Magubike village in Tanzania, through determination of BMR, physical activity level (PAL) and total energy ...

  6. Commodity specific rates of temporal discounting: does metabolic function underlie differences in rates of discounting?

    Science.gov (United States)

    Charlton, Shawn R; Fantino, Edmund

    2008-03-01

    Discounting rates vary as a function of commodity type. Previous studies suggest five potential characteristics of the commodity that could explain these differences: type of reinforcer (primary or secondary), if the commodity is perishable, if the commodity is satiable, if the commodity can be directly consumed, and immediacy of consumption. This paper suggests that these characteristics may best be viewed as related to a more fundamental characteristic: metabolic processing. In order to explore the possibility that metabolic processing underlies changes in discount rates, the difference in discounting between food, money, music CDs, DVDs, and books are compared. Music CDs, DVDs, and books share many characteristics in common with food, including gaining value through a physiological process, but are not directly metabolized. Results are consistent with previous findings of commodity specific discount rates and show that metabolic function plays a role in determining discount rates with those commodities that are metabolized being discounted at a higher rate. These results are interpreted as evidence that the discount rate for different commodities lies along a continuum with those that serve an exchange function rather than a direct function (money) anchoring the low end and those that serve a direct metabolic function capping the high end (food, alcohol, drugs).

  7. Metabolism and Aging : Effects of Cold Exposure on Metabolic Rate, Body Composition, and Longevity in Mice

    NARCIS (Netherlands)

    Vaanholt, Lobke M.; Daan, Serge; Schubert, Kristin A.; Visser, G. Henk

    2009-01-01

    The proposition that increased energy expenditure shortens life has a long history. The rate-of-living theory ( Pearl 1928) states that life span and average mass-specific metabolic rate are inversely proportional. Originally based on interspecific allometric comparisons between species of mammals,

  8. Intraspecific variation in aerobic metabolic rate of fish: relations with organ size and enzyme activity in brown trout.

    Science.gov (United States)

    Norin, Tommy; Malte, Hans

    2012-01-01

    Highly active animals require a high aerobic capacity (i.e., a high maximum metabolic rate [MMR]) to sustain such activity, and it has been speculated that a greater capacity for aerobic performance is reflected in larger organs, which serve as energy processors but are also expensive to maintain and which increase the minimal cost of living (i.e., the basal or standard metabolic rate [SMR]). In this study, we assessed the extent of intraspecific variation in metabolic rate within a group of brown trout (Salmo trutta L.) and tested whether the observed variation in residual (body-mass-corrected) SMR, MMR, and absolute aerobic scope could be explained by variations in the residual size (mass) of metabolically active internal organs. Residual SMR was found to correlate positively with residual MMR, indicating a link between these two metabolic parameters, but no relationship between organ mass and metabolic rate was found for liver, heart, spleen, intestine, or stomach. Instead, activity in the liver of two aerobic mitochondrial enzymes, cytochrome c oxidase and, to a lesser extent, citrate synthase, was found to correlate with whole-animal metabolic rate, indicating that causes for intraspecific variation in the metabolic rate of fish can be found at a lower organizational level than organ size.

  9. Environmental sustainability assessment of urban systems applying coupled urban metabolism and life cycle assessment

    DEFF Research Database (Denmark)

    Birkved, Morten; Goldstein, Benjamin Paul

    2013-01-01

    urban metabolism (UM) and life cycle assessment (LCA) can be applied to assess the sustainability of urban system, taking into account up- and downstream activities directly or indirectly linked to the metabolism of urban systems. Further we apply the fused UM-LCA approach to assess the absolute......The necessity of assessing and addressing the environmental sustainability of urban systems is becoming increasingly relevant due to growing urbanization across the globe, higher consumption in urban systems and related competition for finite resource stocks. In this study we present how fused...... environmental sustainability of large urban systems by relating the environmental sustainability performance of urban systems with global environmental burden boundaries quantifying pollution thresholds beyond which performance of global ecosystems services may be detrimentally affected....

  10. Is basal metabolic rate influenced by age in a long-lived seabird, the snow petrel?

    Science.gov (United States)

    Moe, Børge; Angelier, Frédéric; Bech, Claus; Chastel, Olivier

    2007-10-01

    Ageing is associated with a decline in basal metabolic rate (BMR) in many species, including humans. The evolutionary and physiological causes underlying the relationship between age and BMR are poorly understood. Studies of procellariiform seabirds may provide valuable insight because they have a longer maximum lifespan than expected from their body size and rates of energy metabolism. Such studies are rare, however, because there are few populations with a high proportion of individuals of known age. We performed a cross-sectional study of energy metabolism in relation to age in a long-lived seabird, the snow petrel Pagodroma nivea. In an Antarctic population that has been subject to a long-term research program, including annual banding of chicks since 1963, we measured BMR of individuals aged between 8 and 39 years. We show that the BMR of the snow petrel does not decrease with increasing age. BMR seems to be sustained at a fixed level throughout the investigated age-span. We review this result in light of the disposable soma theory of ageing, and we discuss whether species-specific relationships between age and basal metabolic rate can be related to differences in maximum lifespan.

  11. Applying a Transportation Rating System to Advance Sustainability Evaluation, Planning and Partnerships

    Science.gov (United States)

    Barrella, Elise; Lineburg, Kelsey; Hurley, Peter

    2017-01-01

    Purpose: The purpose of this paper is to describe a pilot application of the Sustainable Transportation Analysis & Rating System (STARS), and highlight how a sustainability rating system can be used to promote sustainable urban development through a university-city partnership. STARS is an example of a second-generation "green"…

  12. Metabolic rate affects adult life span independently of developmental rate in parasitoid wasps

    NARCIS (Netherlands)

    Seyahooei, M.A.; van Alphen, J.J.M.; Kraaijeveld, K.

    2011-01-01

    Developmental time and body size correlate with lifespan in a wide range of taxa, although not in insect parasitoids. When the rate of development is independent of adult metabolic rate, adult lifespan is free to adapt to the adult environment. We suggest that interspecific variation in intrinsic

  13. Basal metabolic rate and the rate of senescence in the great tit

    NARCIS (Netherlands)

    Bouwhuis, Sandra; Sheldon, Ben C.; Verhulst, Simon; Koteja, Pawel

    1. Between-individual variation in rates of senescence has recently been found to relate to natal and early-life conditions in several natural populations. Mechanistic theories of senescence have predicted between-individual variation in basal metabolic rate (BMR) to also underlie such variation in

  14. Sustainability and Chinese Urban Settlements: Extending the Metabolism Model of Emergy Evaluation

    Directory of Open Access Journals (Sweden)

    Lijie Gao

    2016-05-01

    Full Text Available Anthropogenic activity interacts with urban form and inner metabolic processes, ultimately impacting urban sustainability. China’s cities have experienced many environmental issues and metabolic disturbances since the nation-wide market-oriented “reform and opening-up” policy was adopted in the 1980s. To analyze urban reform policy impacts and metabolism sustainability at a settlement scale, this study provides an integrated analysis to evaluate settlement metabolism and sustainability using a combination of emergy analysis and sustainability indicators based on scrutiny of two typical settlements (one pre- and one post-reform. The results reveal that housing reform policy stimulated better planning and construction, thereby improving built environmental quality, mixed functional land use, and residential livability. The pre-reform work-unit settlements are comparatively denser in per capita area but have less mixed land use. Housing reform has spatially changed the work–housing balance and increased commuting travel demand. However, short commuting distances in pre-reform settlements will not always decrease overall motor vehicle usage. Integrating non-commuting transport with local mixed land-use functional planning is a necessary foundation for sustainable urban design. Functional planning should provide convenient facilities and infrastructure, green space, and a suitable household density, and allow for short travel distances; these characteristics are all present in the post-reform settlement.

  15. The determination of standard metabolic rate in fishes

    DEFF Research Database (Denmark)

    Chabot, Denis; Steffensen, John Fleng; Farrell, A.P.

    2016-01-01

    This review and data analysis outline how fish biologists should most reliably estimate the minimal amount of oxygen needed by a fish to support its aerobic metabolic rate (termed standard metabolic rate; SMR). By reviewing key literature, it explains the theory, terminology and challenges...... underlying SMR measurements in fishes, which are almost always made using respirometry (which measures oxygen uptake, ṀO2 ). Then, the practical difficulties of measuring SMR when activity of the fish is not quantitatively evaluated are comprehensively explored using 85 examples of ṀO2 data from different...... fishes and one crustacean, an analysis that goes well beyond any previous attempt. The main objective was to compare eight methods to estimate SMR. The methods were: average of the lowest 10 values (low10) and average of the 10% lowest ṀO2 values, after removing the five lowest ones as outliers (low10...

  16. Body composition and basal metabolic rate in Hidradenitis Suppurativa

    DEFF Research Database (Denmark)

    Miller, I M; Rytgaard, Helene Charlotte; Mogensen, U B

    2016-01-01

    BACKGROUND: Several studies have suggested an association between Hidradenitis Suppurativa (HS) and obesity. Obesity is often expressed as Body Mass Index (BMI). However, BMI lacks information on body composition. General obesity is a predictor of health status and cardiovascular risk, but body.......70-105.56) (P Hidradenitis Suppurativa is associated with a high fat percentage, high visceral fat, and low muscle percentage adding to the morbidity of HS. The higher predicted estimate of basal metabolic rate (BMR) in HS patients may reflect...

  17. Uncinate process length in birds scales with resting metabolic rate.

    Directory of Open Access Journals (Sweden)

    Peter Tickle

    2009-05-01

    Full Text Available A fundamental function of the respiratory system is the supply of oxygen to meet metabolic demand. Morphological constraints on the supply of oxygen, such as the structure of the lung, have previously been studied in birds. Recent research has shown that uncinate processes (UP are important respiratory structures in birds, facilitating inspiratory and expiratory movements of the ribs and sternum. Uncinate process length (UPL is important for determining the mechanical advantage for these respiratory movements. Here we report on the relationship between UPL, body size, metabolic demand and locomotor specialisation in birds. UPL was found to scale isometrically with body mass. Process length is greatest in specialist diving birds, shortest in walking birds and intermediate length in all others relative to body size. Examination of the interaction between the length of the UP and metabolic demand indicated that, relative to body size, species with high metabolic rates have corresponding elongated UP. We propose that elongated UP confer an advantage on the supply of oxygen, perhaps by improving the mechanical advantage and reducing the energetic cost of movements of the ribs and sternum.

  18. Uncinate process length in birds scales with resting metabolic rate.

    Science.gov (United States)

    Tickle, Peter; Nudds, Robert; Codd, Jonathan

    2009-05-27

    A fundamental function of the respiratory system is the supply of oxygen to meet metabolic demand. Morphological constraints on the supply of oxygen, such as the structure of the lung, have previously been studied in birds. Recent research has shown that uncinate processes (UP) are important respiratory structures in birds, facilitating inspiratory and expiratory movements of the ribs and sternum. Uncinate process length (UPL) is important for determining the mechanical advantage for these respiratory movements. Here we report on the relationship between UPL, body size, metabolic demand and locomotor specialisation in birds. UPL was found to scale isometrically with body mass. Process length is greatest in specialist diving birds, shortest in walking birds and intermediate length in all others relative to body size. Examination of the interaction between the length of the UP and metabolic demand indicated that, relative to body size, species with high metabolic rates have corresponding elongated UP. We propose that elongated UP confer an advantage on the supply of oxygen, perhaps by improving the mechanical advantage and reducing the energetic cost of movements of the ribs and sternum.

  19. SUNRA - a sustainability rating system framework for National Road Administrations

    DEFF Research Database (Denmark)

    Sowerby, Chris; Langstraat, James; Harmer, Clare

    National Road Administrations (NRAs) across Europe strive to improve the performance of their road networks. This improvement has been underpinned by significant research in the optimisation of road planning, design, construction and maintenance, which has enhanced the understanding of the social......, environmental and economic aspects of managing a road network. Whilst there is common understanding in some aspects of sustainability there is not a common understanding of sustainability as a whole and thus how to benchmark and improve overall performance. The Sustainability: National Road Administrations...

  20. Rhythmic and sustained oscillations in metabolism and gene expression of Cyanothece sp. ATCC 51142 under constant light

    Directory of Open Access Journals (Sweden)

    Sandeep Bhupendra Gaudana

    2013-12-01

    Full Text Available Cyanobacteria, a group of photosynthetic prokaryotes, oscillate between day and night time metabolisms with concomitant oscillations in gene expression in response to light/dark cycles (LD. The oscillations in gene expression have been shown to sustain in constant light (LL with a free running period of 24 h in a model cyanobacterium Synechococcus elongatus PCC 7942. However, equivalent oscillations in metabolism are not reported under LL in this non-nitrogen fixing cyanobacterium. Here we focus on Cyanothece sp. ATCC 51142, a unicellular, nitrogen-fixing cyanobacterium known to temporally separate the processes of oxygenic photosynthesis and oxygen-sensitive nitrogen fixation. In a recent report, metabolism of Cyanothece 51142 has been shown to oscillate between photosynthetic and respiratory phases under LL with free running periods that are temperature dependent but significantly shorter than the circadian period. Further, the oscillations shift to circadian pattern at moderate cell densities that are concomitant with slower growth rates. Here we take this understanding forward and demonstrate that the utradian rhythm under LL sustains at much higher cell densities when grown under turbulent regimes that simulate flashing light effect. Our results suggest that the ultradian rhythm in metabolism may be needed to support higher carbon and nitrogen requirements of rapidly growing cells under LL. With a comprehensive Real time PCR based gene expression analysis we account for key regulatory interactions and demonstrate the interplay between clock genes and the genes of key metabolic pathways. Further, we observe that several genes that peak at dusk in Synechococcus peak at dawn in Cyanothece and vice versa. The circadian rhythm of this organism appears to be more robust with peaking of genes in anticipation of the ensuing photosynthetic and respiratory metabolic phases.

  1. Regulation of metabolic rate and substrate utilization by zinc deficiency.

    Science.gov (United States)

    Evans, Stephanie A; Overton, J Michael; Alshingiti, Almamoun; Levenson, Cathy W

    2004-06-01

    The trace metal zinc (Zn) is essential for the catalytic activity of many enzymes involved in energy nutrient metabolism and appears to regulate hormones, such as insulin, leptin, and thyroid hormone that play key roles in metabolism. Thus, this study used the continuous monitoring of oxygen consumption, carbon dioxide production, locomotion, and food intake to determine the effect of dietary Zn restriction on metabolic rate (MR), basal metabolic rate (BMR), and respiratory quotient (RQ). Rats were fed a Zn-adequate (ZA, 28 ppm) or Zn-deficient (ZD, food intake that characteristically occur in ZD rats, an additional group was pair-fed (PF) the same amount ZA food eaten by ZD rats. The mean caloric intake of ZD rats was significantly lower than ZA rats by day 3. By day 8, ZD and PF rats weighed 64% and 67% of ZA rats, respectively, (P rats (316 +/- 43 m) was 6 times that of ZA (53 +/- 6 m). Despite the fact that PF and ZD rats had the same food intake, there was no increase in locomotor activity in ZD rats suggesting that the mechanisms responsible for increased physical activity in food restricted animals may be Zn dependent. Furthermore, differences in activity between PF and ZD animals were not reflected in differences in MR. Both ZD and PF significantly reduced MR compared with ZA rats beginning on day 4. There was a significant relationship between RQ and caloric intake (r = 0.708, P <.01), but no specific effect of Zn status. Thus, while there may be an effect of Zn on locomotion and the energetic cost of activity, it appears that the most profound effect of Zn status on MR and substrate utilization is the result of Zn deficiency-induced anorexia.

  2. A decision-support system for sustainable urban metabolism in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Ainhoa, E-mail: ainhoag@yahoo.com [Trinity Centre for Biodiversity Research, School of Natural Sciences, Trinity College Dublin, College Green, Dublin 2 (Ireland); Donnelly, Alison, E-mail: donnelac@tcd.ie [Centre for the Environment, School of Natural Sciences, Trinity College Dublin (Ireland); Jones, Mike, E-mail: mike.jones@tcd.ie [Discipline of Botany, School of Natural Sciences, Trinity College Dublin (Ireland); Chrysoulakis, Nektarios, E-mail: zedd2@iacm.forth.gr [Foundation for Research and Technology-Hellas, Institute of Applied and Computational Mathematics (Greece); Lopes, Myriam, E-mail: myr@ua.pt [Departamento de Ambiente e Ordenamento and CESAM, University of Aveiro (Portugal)

    2013-01-15

    Urban metabolism components define the energy and material exchanges within a city and, therefore, can provide valuable information on the environmental quality of urban areas. Assessing the potential impact of urban planning alternatives on urban metabolism components (such as energy, water, carbon and pollutants fluxes) can provide a quantitative estimation of their sustainability performance. Urban metabolism impact assessment can, therefore, contribute to the identification of sustainable urban structures with regards, for example, to building types, materials and layout, as well as to location and capacity of transportation and infrastructural developments. In this way, it enables the formulation of planning and policy recommendations to promote efficient use of resources and enhance environmental quality in urban areas. The European FP7 project BRIDGE (sustainaBle uRban plannIng Decision support accountinG for urban mEtabolism) has developed a decision-support system (DSS) that systematically integrates urban metabolism components into impact assessment processes with the aim of accurately quantifying the potential effects of proposed planning interventions. The DSS enables integration of multiple spatial and non-spatial datasets (e.g. physical flows of energy and material with variables of social and economic change) in a systematic manner to obtain spatially defined assessment results and to thus inform planners and decision-makers. This multi-criteria approach also enables incorporation of stakeholders' perceptions in order to prioritise decisive assessment criteria. This paper describes the methodological framework used to develop the DSS and critically examines the results of its practical application in five European cities. - Highlights: Black-Right-Pointing-Pointer Urban metabolism in sustainability assessment of planning alternatives. Black-Right-Pointing-Pointer European FP7 project applied to 5 real life case studies across Europe. Black

  3. Does growth rate determine the rate of metabolism in shorebird chicks living in the arctic?

    NARCIS (Netherlands)

    Williams, Joseph B.; Tieleman, B. Irene; Visser, G. Henk; Ricklefs, Robert E.

    2007-01-01

    We measured resting and peak metabolic rates (RMR and PMR, respectively) during development of chicks of seven species of shorebirds: least sandpiper (Calidris minutilla; adult mass 20 22 g), dunlin (Calidris alpina; 56-62 g), lesser yellowlegs (Tringa flavipes; 88-92 g), short-billed dowitcher

  4. Effect of growth rate and body mass on resting metabolic rate in galliform chicks

    NARCIS (Netherlands)

    Dietz, MW; Drent, RH

    1997-01-01

    In this study, we asked whether within-species variation in chick resting metabolic rate was related to variation in growth and whether this relationship changed during development in three galliform species (turkey, Meleagris gallopavo, guinea fowl, Numida meleagris, and Japanese quail, Coturnix

  5. Metabolic rate and accelerometer output during walking in people with Down syndrome

    National Research Council Canada - National Science Library

    Agiovlasitis, Stamatis; Motl, Robert W; Fahs, Christopher A; Ranadive, Sushant M; Yan, Huimin; Echols, George H; Rossow, Lindy; Fernhall, Bo

    2011-01-01

    People with Down syndrome (DS) have reduced gait stability and aerobic fitness that increase the metabolic rate during walking, potentially altering the relationship between metabolic rate and accelerometer output and lowering...

  6. Effect of Different Types of Food on Metabolic Rate in Rats | Azeez ...

    African Journals Online (AJOL)

    ... metabolic rate of the two foods in each of the groups was compared. . Also it was concluded that a large meal size would stimulate the metabolic rate to the same extent as a small meal size provided the minimum requirement is met. Keywords: Metabolic rate, Carbohydrate Protein, Fat, Food. NQJHM Vol. 16 (2) 2006: pp.

  7. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise.

    Science.gov (United States)

    Sadeghi, Masoumeh; Gharipour, Mojgan; Nezafati, Pouya; Shafie, Davood; Aghababaei, Esmaeil; Sarrafzadegan, Nizal

    2016-11-01

    The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS) patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III) definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC) curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5%) were diagnosed as MetS. The mean resting heart rate (RHR) was not statistically different between the two groups (P=0.078). However, the mean maximum heart (MHR) rate was considerably higher in participants with MetS (142.37±14.84 beats per min) compared to the non-MetS group (134.62±21.63 beats per min) (Pgroup, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033) and was inversely associated with age (β=-0.469, Page. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  8. Substitution rates of organelle and nuclear genes in sharks: implicating metabolic rate (again).

    Science.gov (United States)

    Martin, A P

    1999-07-01

    Rates of nucleotide substitution for nuclear genes are thought to be governed primarily by the number of germ line replication events (the so-called "generation time" hypothesis). In contrast, rates of mitochondrial DNA evolution appear to be set primarily by DNA damage pathways of mutation mediated by mutagenic by-products of oxidative phosphorylation (the so-called "metabolic-rate" hypothesis). Comparison of synonymous substitution rates estimated for the mitochondrial cytochrome b gene and nuclear-encoded dlx, hsp70, and RAG-1 genes in mammals and sharks shows that rates of molecular evolution for sharks are approximately an order of magnitude slower than those for mammals for both nuclear and mitochondrial genes. In addition, there is significant positive covariation of substitution rate for mitochondrial and nuclear genes within sharks. These results, interpreted in light of the pervasiveness of DNA damage by mutagenic by-products of oxygen metabolism to both nuclear and mitochondrial genes and coupled with increasing evidence for cross-genome activity of DNA repair enzymes, suggest that molecular clocks for mitochondrial and nuclear genes may be set primarily by common mutational mechanisms.

  9. Bats and birds: Exceptional longevity despite high metabolic rates.

    Science.gov (United States)

    Munshi-South, Jason; Wilkinson, Gerald S

    2010-01-01

    Bats and birds live substantially longer on average than non-flying mammals of similar body size. The combination of small body size, high metabolic rates, and long lifespan in bats and birds would not seem to support oxidative theories of ageing that view senescence as the gradual accumulation of damage from metabolic byproducts. However, large-scale comparative analyses and laboratory studies on a few emerging model species have identified multiple mechanisms for resisting oxidative damage to mitochondrial DNA and cellular structures in both bats and birds. Here we review these recent findings, and suggest areas in which additional progress on ageing mechanisms can be made using bats and birds as novel systems. New techniques for determining the age of free-living, wild individuals, and robustly supported molecular phylogenies, are under development and will improve the efforts of comparative biologists to identify ecological and evolutionary factors promoting long lifespan. In the laboratory, greater development of emerging laboratory models and comparative functional genomic approaches will be needed to identify the molecular pathways of longevity extension in birds and bats. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  10. Individual variation in metabolic reaction norms over ambient temperature causes low correlation between basal and standard metabolic rate

    NARCIS (Netherlands)

    Briga, Michael; Verhulst, Simon

    2017-01-01

    Basal metabolic rate (BMR) is often assumed to be indicative of the energy turnover at ambient temperatures (T-a) below the thermoneutral zone (SMR), but this assumption has remained largely untested. Using a new statistical approach, we quantified the consistency in nocturnal metabolic rate across

  11. Assessing Metabolic Syndrome Through Increased Heart Rate During Exercise

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2016-12-01

    Full Text Available The present study aimed to assess changes in resting and maximum heart rates as primary indicators of cardiac autonomic function in metabolic syndrome (MetS patients and to determine their value for discriminating MetS from non-MetS. 468 participants were enrolled in this cross-sectional study and assessed according to the updated adult treatment panel III (ATP-III definition of MetS. Resting and maximum heart rates were recorded following the Bruce protocol during an exercise. A receiver operating characteristic (ROC curve was used to identify the best cutoff point for discriminating MetS from the non-MetS state. 194 participants (41.5% were diagnosed as MetS. The mean resting heart rate (RHR was not statistically different between the two groups (P=0.078. However, the mean maximum heart (MHR rate was considerably higher in participants with MetS (142.37±14.84 beats per min compared to the non-MetS group (134.62±21.63 beats per min (P<0.001. In the MetS group, the MHR was positively correlated with the serum triglyceride level (β=0.185, P=0.033 and was inversely associated with age (β=-0.469, P<0.001. The MHR had a moderate value for discriminating MetS from the non-MetS state (c=0.580, P=0.004 with the optimal cutoff point of 140 beats per min. In MetS patients, the MHR was significantly greater compared to non-MetS subjects and was directly correlated with serum triglyceride levels and inversely with advanced age. Moreover, MHR can be used as a suspicious indicator for identifying MetS.

  12. Correlation Between Ecospace and Metabolic Rate of Marine Organisms Through Geologic Time

    Science.gov (United States)

    Duong, C.; Tenorio, A.; Heim, N. A.; Payne, J.

    2015-12-01

    Marine organisms are the most abundant fossils scientists have discovered in the fossil record. Various factors affect the survival rate of individual organisms and entire genera including metabolic rate, genetic diversity, environmental availability, and ecology. We however chose to focus our attention on studying mean metabolic rates in correlation to life modes. A marine organism's life mode is determined by three criteria: tiering, motility, and feeding mechanism. We believe an organism's life mode has an effect on its survivorship, especially since ecospace is the "primary determinant of routine metabolic rate for marine organisms" (Seibel & Drazen 2007). Using the metabolic equation, we were able to plot metabolic rate changes for various life modes over time. Seibel and Drazen (2007) explain that "metabolic variation in the ocean results from interspecific differences in ecological energy demand," thus allowing us to hypothesize that with different combinations of life modes, different marine organisms will have varying metabolic rates. To further compare our data, we created a heatmap to show the change in metabolic rates over the last 540 million years. Based on the collection of data, metabolic rates of marine organisms have shown an increasing trend. When analyzing ecospaces, pelagic (living in the water column), free moving organisms have relatively high metabolic rates in comparison to other modes of tiering. In other life modes, there's a general trend of genera maintaining a stabilized and moderate metabolic rate that is neither extremely high nor low.

  13. Canadian STARS-Rated Campus Sustainability Plans: Priorities, Plan Creation and Design

    Directory of Open Access Journals (Sweden)

    Lauri Lidstone

    2015-01-01

    Full Text Available The use of integrated sustainability plans is an emerging trend in higher education institutions (HEIs to set sustainability priorities and to create a work plan for action. This paper analyses the sustainability plans of 21 Canadian HEIs that have used the Sustainability Tracking, Assessment and Rating System (STARS from the Association for the Advancement of Sustainability in Higher Education (AASHE. The plans were coded thematically with a focus on the sustainability goals, process of plan creation, and aspects of plan design outlined in the texts. This paper finds that sustainability goals focused on the environmental aspects of sustainability, while social and economic aspects were less emphasized. Further, most plans were described as being created through a broad stakeholder-consultation process, while fewer plans assigned timelines and parties responsible to sustainability goals. This paper contributes to our understanding of the priorities of Canadian HEI institutions at the end of the Decade of Education for Sustainable Development and is useful for practitioners interested in developing their own sustainability plans.

  14. Phylogenetic analysis of the allometry of metabolic rate and mitochondrial basal proton leak.

    Science.gov (United States)

    Polymeropoulos, Elias T; Oelkrug, R; White, C R; Jastroch, M

    2017-08-01

    The mitochondrial basal proton leak (MBPL) significantly contributes to high body temperatures (Tb) and basal metabolic rates (BMR) in endotherms. In endotherms at a given body mass (M), liver MBPL is higher than in ectotherms, supporting the notion that MBPL may partly explain the evolutionary increase in metabolic rate (MR), fostering endothermy. Here, we re-addressed this assumption by performing a phylogenetic analysis comparing all available liver MBPL data for ecto- and endotherms. While MBPL within endotherms negatively scales with M and BMR as shown previously, MBPL of ectotherms does not scale allometrically with M. Phylogenetic analysis reveals that this result is confounded by a positive scaling coefficient for MBPL with M for reptiles. Strikingly, the reptilian MBPL reaches endothermic levels above a body mass of 6.6kg. Thus, phylogenetic scaling of MBPL supports previous claims of endotherm-like physiological characteristics in large reptiles. It appears that diversification of ancestral ectothermic tetrapods to a body mass of at least 6kg may have been required to reach a MBPL that is beneficial for sustained high body temperatures. Novel MBPL data for the lesser hedgehog tenrec, a protoendothermic eutherian that displays reptile-like thermoregulatory patterns, fall within the endo- and ectothermic allometric regressions. Finally, we add additional evidence that within endotherms, phylogenetic differences in MR do not correlate with MBPL. Collectively, these data suggest that MBPL does not universally scale with metabolic rate in ecto- or endotherms and that an increasing MBPL with M may have played an important physiological role in the evolutionary history of reptilian thermoregulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Sources and significance of variation in basal, summit and maximal metabolic rates in birds

    Directory of Open Access Journals (Sweden)

    Andrew E. MCKECHNIE, David L. SWANSON

    2010-12-01

    Full Text Available The rates at which birds use energy may have profound effects on fitness, thereby influencing physiology, behavior, ecology and evolution. Comparisons of standardized metabolic rates (e.g., lower and upper limits of metabolic power output present a method for elucidating the effects of ecological and evolutionary factors on the interface between physiology and life history in birds. In this paper we review variation in avian metabolic rates [basal metabolic rate (BMR; minimum normothermic metabolic rate, summit metabolic rate (Msum; maximal thermoregulatory metabolic rate, and maximal metabolic rate (MMR; maximal exercise metabolic rate], the factors associated with this variation, the evidence for functional links between these metabolic traits, and the ecological and evolutionary significance of avian metabolic diversity. Both lower and upper limits to metabolic power production are phenotypically flexible traits, and vary in association with numerous ecological and evolutionary factors. For both inter- and intraspecific comparisons, lower and upper limits to metabolic power production are generally upregulated in response to energetically demanding conditions and downregulated when energetic demands are relaxed, or under conditions of energetic scarcity. Positive correlations have been documented between BMR, Msum and MMR in some, but not all studies on birds, providing partial support for the idea of a functional link between lower and upper limits to metabolic power production, but more intraspecific studies are needed to determine the robustness of this conclusion. Correlations between BMR and field metabolic rate (or daily energy expenditure, in birds are variable, suggesting that the linkage between these traits is subject to behavioral adjustment, and studies of the relationship between field and maximal metabolic rates are lacking. Our understanding of avian metabolic diversity would benefit from future studies of: (1 the functional

  16. Alternative aviation jet fuel sustainability evaluation report - task 3 : sustainability criteria and rating systems for the use in aircraft alternative fuel supply chain

    Science.gov (United States)

    2013-03-31

    This report identifies criteria that can be used to evaluate the sustainability of biofuels introduced into the aviation fuel supply chain. It describes the inputs, criteria and outputs that can be used in a sustainability rating system. It identifie...

  17. The determination of standard metabolic rate in fishes.

    Science.gov (United States)

    Chabot, D; Steffensen, J F; Farrell, A P

    2016-01-01

    This review and data analysis outline how fish biologists should most reliably estimate the minimal amount of oxygen needed by a fish to support its aerobic metabolic rate (termed standard metabolic rate; SMR). By reviewing key literature, it explains the theory, terminology and challenges underlying SMR measurements in fishes, which are almost always made using respirometry (which measures oxygen uptake, ṀO2 ). Then, the practical difficulties of measuring SMR when activity of the fish is not quantitatively evaluated are comprehensively explored using 85 examples of ṀO2 data from different fishes and one crustacean, an analysis that goes well beyond any previous attempt. The main objective was to compare eight methods to estimate SMR. The methods were: average of the lowest 10 values (low10) and average of the 10% lowest ṀO2 values, after removing the five lowest ones as outliers (low10%), mean of the lowest normal distribution (MLND) and quantiles that assign from 10 to 30% of the data below SMR (q0·1 , q0·15 , q0·2 , q0·25 and q0·3 ). The eight methods yielded significantly different SMR estimates, as expected. While the differences were small when the variability was low amongst the ṀO2 values, they were important (>20%) for several cases. The degree of agreement between the methods was related to the c.v. of the observations that were classified into the lowest normal distribution, the c.v. MLND (C.V.MLND ). When this indicator was low (≤5·4), it was advantageous to use the MLND, otherwise, one of the q0·2 or q0·25 should be used. The second objective was to assess if the data recorded during the initial recovery period in the respirometer should be included or excluded, and the recommendation is to exclude them. The final objective was to determine the minimal duration of experiments aiming to estimate SMR. The results show that 12 h is insufficient but 24 h is adequate. A list of basic recommendations for practitioners who use respirometry

  18. Heart rate variability and sustained attention in ADHD children

    NARCIS (Netherlands)

    Börger, N.A.; Van der Meere, J.J.; Ronner, A.; Alberts, E.; Geuze, R.H.; Bogte, H

    The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a

  19. Sustainable systems rating program: Marketing ``Green`` Building in Austin, Texas

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    Four major resource issues for home construction were identified: water, energy, materials, and waste. A systems flow model was then developed that tracked the resource issues through interactive matrices in the areas of sourcing, processing, using, and disposing or recycling. This model served as the basis for a rating system used in an educational and marketing tool called the Eco-Home Guide.

  20. Decreased resting metabolic rate in ballet dancers with menstrual irregularity.

    Science.gov (United States)

    Myburgh, K H; Berman, C; Novick, I; Noakes, T; Lambert, E

    1999-09-01

    We studied 21 ballet dancers aged 19.4 +/- 1.4 years, hypothesizing that undernutrition was a major factor in menstrual irregularity in this population. Menstrual history was determined by questionnaire. Eight dancers had always been regular (R). Thirteen subjects had a history of menstrual irregularity (HI). Of these, 2 were currently regularly menstruating, 3 had short cycles, 6 were oligomenorrheic, and 2 were amenorrheic. Subjects completed a weighed dietary record and an Eating Attitudes Test (EAT). The following physiological parameters were measured: body composition by anthropometry, resting metabolic rate (RMR) by open-circuit indirect calorimetry, and serum thyroid hormone concentrations by radioimmunoassay. R subjects had significantly higher RMR than HI subjects. Also, HI subjects had lower RMR than predicted by fat-free mass, compared to the R subjects. Neither reported energy intake nor serum thyroid hormone concentrations were different between R and HI subjects. EAT scores varied and were not different between groups. We concluded that in ballet dancers, low RMR is more strongly associated with menstrual irregularity than is current reported energy intake or serum thyroid hormone concentrations.

  1. Scaling of standard metabolic rate in estuarine crocodiles Crocodylus porosus.

    Science.gov (United States)

    Seymour, Roger S; Gienger, C M; Brien, Matthew L; Tracy, Christopher R; Charlie Manolis, S; Webb, Grahame J W; Christian, Keith A

    2013-05-01

    Standard metabolic rate (SMR, ml O2 min(-1)) of captive Crocodylus porosus at 30 °C scales with body mass (kg) according to the equation, SMR = 1.01 M(0.829), in animals ranging in body mass of 3.3 orders of magnitude (0.19-389 kg). The exponent is significantly higher than 0.75, so does not conform to quarter-power scaling theory, but rather is likely an emergent property with no single explanation. SMR at 1 kg body mass is similar to the literature for C. porosus and for alligators. The high exponent is not related to feeding, growth, or obesity of captive animals. The log-transformed data appear slightly curved, mainly because SMR is somewhat low in many of the largest animals (291-389 kg). A 3-parameter model is scarcely different from the linear one, but reveals a declining exponent between 0.862 and 0.798. A non-linear model on arithmetic axes overestimates SMR in 70% of the smallest animals and does not satisfactorily represent the data.

  2. Predicting demographically sustainable rates of adaptation : Can great tit breeding time keep pace with climate change?

    NARCIS (Netherlands)

    Gienapp, Phillip; Lof, Marjolein; Reed, Thomas E.; McNamara, John; Verhulst, Simon; Visser, Marcel E.

    2013-01-01

    Populations need to adapt to sustained climate change, which requires micro-evolutionary change in the long term. A key question is how the rate of this micro-evolutionary change compares with the rate of environmental change, given that theoretically there is a 'critical rate of environmental

  3. Assesment of Autonomic Function in Metabolic Syndrome using Combination Heart Rate Variability and Heart Rate Turbulence

    Directory of Open Access Journals (Sweden)

    Gülay Aydın

    2013-12-01

    Full Text Available INTRODUCTION: Metabolic syndrome (MetS is described as a group of various abnormal metabolic risk factors such as obesity, dyslipidemia, increased blood pressure, increased plasma glucose levels, prothrombotic condition and proinflammatory state. These parameters are related to decreased parasympathetic and increased sympathetic activity. We aimed to evaluate autonomic function using a combination with heart rate variability (HRV and heart rate turbulence (HRT in metabolic syndrome to compare non-metabolic syndrome(non-MetS. METHODS: We selected consecutive 50 patients with MetS and 50 patients with healthy non-MetS individuals. All patients underwent 24 hours holter monitoring to evaluate HRT and HRV parameters. RESULTS: Age of patients was not different in two groups. Mean age of MetS patients was 57,50±12,13 and 54,6±10,25 in non- MetS individuals. Sex of patients was non different in MetS compared to non-MetS (37 female and 13 male vs. 22 female, 28 male p<0,05 respectively. SDNN and RMSSD was lower in MetS compared to those without MetS (131,96±49,12 vs 179,59±85,83 p=0,03 and 78,64±35,22 vs 112,73±81,24 p=0,08 respectively. SDANN, pNN50,Mean RR, mean heart rate, count of ventricular premature complex(VPC were not different between two groups. Turbulence Slope(TS was not different in two groups. Turbulence Onset(TO was higher in MetS compared to non-MetS (2,01±15,29 and -6,21±13,5 p=0,005. DISCUSSION AND CONCLUSION: We showed that autonomic function in MetS was impaired using a combination with HRT and HRV. These patients should be followed closely for adverse cardiovascular outcome especially including cardiac arrhythmia.

  4. Advantages of integrated and sustainability based assessment for metabolism based strategic planning of urban water systems.

    Science.gov (United States)

    Behzadian, Kourosh; Kapelan, Zoran

    2015-09-15

    Despite providing water-related services as the primary purpose of urban water system (UWS), all relevant activities require capital investments and operational expenditures, consume resources (e.g. materials and chemicals), and may increase negative environmental impacts (e.g. contaminant discharge, emissions to water and air). Performance assessment of such a metabolic system may require developing a holistic approach which encompasses various system elements and criteria. This paper analyses the impact of integration of UWS components on the metabolism based performance assessment for future planning using a number of intervention strategies. It also explores the importance of sustainability based criteria in the assessment of long-term planning. Two assessment approaches analysed here are: (1) planning for only water supply system (WSS) as a part of the UWS and (2) planning for an integrated UWS including potable water, stormwater, wastewater and water recycling. WaterMet(2) model is used to simulate metabolic type processes in the UWS and calculate quantitative performance indicators. The analysis is demonstrated on the problem of strategic level planning of a real-world UWS to where optional intervention strategies are applied. The resulting performance is assessed using the multiple criteria of both conventional and sustainability type; and optional intervention strategies are then ranked using the Compromise Programming method. The results obtained show that the high ranked intervention strategies in the integrated UWS are those supporting both water supply and stormwater/wastewater subsystems (e.g. rainwater harvesting and greywater recycling schemes) whilst these strategies are ranked low in the WSS and those targeting improvement of water supply components only (e.g. rehabilitation of clean water pipes and addition of new water resources) are preferred instead. Results also demonstrate that both conventional and sustainability type performance indicators

  5. Systems metabolic engineering as an enabling technology in accomplishing sustainable development goals.

    Science.gov (United States)

    Yang, Dongsoo; Cho, Jae Sung; Choi, Kyeong Rok; Kim, Hyun Uk; Lee, Sang Yup

    2017-09-01

    With pressing issues arising in recent years, the United Nations proposed 17 Sustainable Development Goals (SDGs) as an agenda urging international cooperations for sustainable development. In this perspective, we examine the roles of systems metabolic engineering (SysME) and its contribution to improving the quality of life and protecting our environment, presenting how this field of study offers resolutions to the SDGs with relevant examples. We conclude with offering our opinion on the current state of SysME and the direction it should move forward in the generations to come, explicitly focusing on addressing the SDGs. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  6. The difference between lending interest rate and funds interest rate. Link with sustainable banking. Particularities of Romanian Market

    Directory of Open Access Journals (Sweden)

    Cristian Gheorghe Iacob

    2015-05-01

    Full Text Available The article, is trying to capture the way difference between active and passive interest rates influence macroeconomic sustainable development in a country. However the theory is limited on this area and the author is intending to merge practical aspects with conceptual terms. The role of banks in an economy is very important, as all inflows and outflows are done through financial institutions. Bank sustainability is the area of study and practice that captures the contribution of banks in sustainable development of a country. Banking instruments are the means by which banks are present and act in the economy. Banking techniques are the mechanisms of banking instruments. The most important banking instruments are the loans and the deposits. So banks take deposits from different entities and use them as resource to finance other entities. A bank is considered contributing to sustainable development, if lending divisions allocates resources to investments that bring long-term welfare to the community not only for today people, but for future generations. Therefore, we can establish a correlation between banking sustainability and sustainable development through the evolution of banking instruments. Looking to detail, bank sustainability is highly affected by the local macroeconomic issues, but also from global influences.

  7. Inbreeding effects on standard metabolic rate investigated at cold, benign and hot temperatures in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Jensen, Palle; Overgaard, Johannes; Loeschcke, Volker

    2014-01-01

    . It has been suggested that damage incurred from increased homozygosity entails energetic cost associated with cellular repair. However, little is known about the effects of inbreeding on standard metabolic rate. Using stop-flow respirometry we performed repeated measurements of metabolic rate...... of standard metabolic rate. Due to the potentially added costs of genetic stress in inbred lines we hypothesized that inbred individuals have increased metabolic rate compared to outbred controls and that this is more pronounced at stressful temperatures due to synergistic inbreeding by environment...... to the outbred control lines with some inbred lines having very high or low standard metabolic rate. Thus genetic drift and not inbreeding per se seem to explain variation in metabolic rate in populations of different size....

  8. Body Composition and Basal Metabolic Rate in Women with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Marina de Figueiredo Ferreira

    2014-01-01

    Full Text Available Objective. The aim of this study was to determine which of the seven selected equations used to predict basal metabolic rate most accurately estimated the measured basal metabolic rate. Methods. Twenty-eight adult women with type 2 diabetes mellitus participated in this cross-sectional study. Anthropometric and biochemical variables were measured as well as body composition (by absorptiometry dual X-ray emission and basal metabolic rate (by indirect calorimetry; basal metabolic rate was also estimated by prediction equations. Results. There was a significant difference between the measured and the estimated basal metabolic rate determined by the FAO/WHO/UNU (Pvalue<0.021 and Huang et al. (Pvalue≤0.005 equations. Conclusion. The calculations using Owen et al’s. equation were the closest to the measured basal metabolic rate.

  9. Validation of resting metabolic rate prediction equations for teenagers

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Santos da Fonseca

    2007-09-01

    Full Text Available The resting metabolic rate (RMR can be defi ned as the minimum rate of energy spent and represents the main component of the energetic outlay. The purpose of this study is to validate equations to predict the resting metabolic rate in teenagers (103 individuals, being 51 girls and 52 boys, with age between 10 and 17 years from Florianópolis – SC – Brazil. It was measured: the body weight, body height, skinfolds and obtained the lean and body fat mass through bioimpedance. The nonproteic RMR was measured by Weir’s equation (1949, utilizing AeroSport TEEM-100 gas analyzer. The studied equations were: Harry and Benedict (1919, Schofi eld (1985, WHO/FAO/UNU (1985, Henry and Rees (1991, Molnár et al. (1998, Tverskaya et al. (1998 and Müller et al. (2004. In order to study the cross-validation of the RMR prediction equations and its standard measure (Weir 1949, the following statistics procedure were calculated: Pearson’s correlation (r ≥ 0.70, the “t” test with the signifi cance level of p0.05 in relation to the standard measure, with exception of the equations suggested for Tverskaya et al. (1998, and the two models of Müller et al (2004. Even though there was not a signifi cant difference, only the models considered for Henry and Rees (1991, and Molnár et al. (1995 had gotten constant error variation under 5%. All the equations analyzed in the study in girls had not reached criterion of correlation values of 0.70 with the indirect calorimetry. Analyzing the prediction equations of RMR in boys, all of them had moderate correlation coeffi cients with the indirect calorimetry, however below 0.70. Only the equation developed for Tverskaya et al. (1998 presented differences (p ABSTRACT0,05 em relação à medida padrão (Weir 1949, com exceção das equações sugeridas por Tverskaya et al. (1998 e os dois modelos de Müller et al (2004. Mesmo não havendo diferença signifi cativa, somente os modelos propostos por Henry e Rees (1991

  10. Individual variation in metabolic reaction norms over ambient temperature causes low correlation between basal and standard metabolic rate

    OpenAIRE

    Briga, Michael; Verhulst, Simon

    2017-01-01

    Basal metabolic rate (BMR) is often assumed to be indicative of the energy turnover at ambient temperatures (T-a) below the thermoneutral zone (SMR), but this assumption has remained largely untested. Using a new statistical approach, we quantified the consistency in nocturnal metabolic rate across a temperature range in zebra finches (N=3213 measurements on 407 individuals) living permanently in eight outdoor aviaries. Foraging conditions were either benign or harsh, and body mass and mass-a...

  11. Estimates of metabolic rate and major constituents of metabolic demand in fishes under field conditions: Methods, proxies, and new perspectives.

    Science.gov (United States)

    Treberg, Jason R; Killen, Shaun S; MacCormack, Tyson J; Lamarre, Simon G; Enders, Eva C

    2016-12-01

    Metabolic costs are central to individual energy budgets, making estimates of metabolic rate vital to understanding how an organism interacts with its environment as well as the role of species in their ecosystem. Despite the ecological and commercial importance of fishes, there are currently no widely adopted means of measuring field metabolic rate in fishes. The lack of recognized methods is in part due to the logistical difficulties of measuring metabolic rates in free swimming fishes. However, further development and refinement of techniques applicable for field-based studies on free swimming animals would greatly enhance the capacity to study fish under environmentally relevant conditions. In an effort to foster discussion in this area, from field ecologists to biochemists alike, we review aspects of energy metabolism and give details on approaches that have been used to estimate energetic parameters in fishes. In some cases, the techniques have been applied to field conditions; while in others, the methods have been primarily used on laboratory held fishes but should be applicable, with validation, to fishes in their natural environment. Limitations, experimental considerations and caveats of these measurements and the study of metabolism in wild fishes in general are also discussed. Potential novel approaches to FMR estimates are also presented for consideration. The innovation of methods for measuring field metabolic rate in free-ranging wild fish would revolutionize the study of physiological ecology. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Resting metabolic rate prediction equations in teenagers: history and validity

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Santos da Fonseca

    2008-01-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n4p405 The resting metabolic rate (RMR has been utilized routinely by clinics to predict the energy necessary for patients. Additionally, governmental agencies and health organizations define the energy necessary for the population and the energy orientation for athletes who play sports. Many recognize the value of the RMR, but it is not always possible to measure it by using calorimetry, so it is suggested to use equations of prediction for this variable. However, RMR prediction equations must be used in such a way that allows its frequent reexamination to guarantee efficiency. This article has three purposes: 1 to analyze the development history of the traditional equations by Harris and Benedict (1919, Schofield (1985, WHO/FAO/UNU (1985, and Henry and Rees (1991 (these authors routinely used the traditional equations to measure the RMR in teenagers; 2 to analyze the studies that tested the validity of these equations in the population of teenagers; 3 to argue and point out possible intervening factors on the RMR results of teenagers, thus guiding to election of independent variables when developing equations for Brazilian’s population. After analyzing the equations, it is possible to conclude that: 1 the equations had been developed by having a given base of compiled evaluations from the beginning of the Twentieth Century; 2 the studies that tested the validity of these equations demonstrated great variability in the results, confirming the impossibility to have a unique/universal equation. This study also showed that new RMR prediction equations must be developed for specific populations taking into consideration the race and where the individual resides.

  13. Resting metabolic rate prediction equations in teenagers: history and validity

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Santos da Fonseca

    2008-12-01

    Full Text Available The resting metabolic rate (RMR has been utilized routinely by clinics to predict the energy necessary forpatients. Additionally, governmental agencies and health organizations define the energy necessary for the population andthe energy orientation for athletes who play sports. Many recognize the value of the RMR, but it is not always possible tomeasure it by using calorimetry, so it is suggested to use equations of prediction for this variable. However, RMR predictionequations must be used in such a way that allows its frequent reexamination to guarantee efficiency. This article has threepurposes: 1 to analyze the development history of the traditional equations by Harris and Benedict (1919, Schofield (1985,WHO/FAO/UNU (1985, and Henry and Rees (1991 (these authors routinely used the traditional equations to measure theRMR in teenagers; 2 to analyze the studies that tested the validity of these equations in the population of teenagers; 3 toargue and point out possible intervening factors on the RMR results of teenagers, thus guiding to election of independentvariables when developing equations for Brazilian’s population. After analyzing the equations, it is possible to conclude that:1 the equations had been developed by having a given base of compiled evaluations from the beginning of the TwentiethCentury; 2 the studies that tested the validity of these equations demonstrated great variability in the results, confirmingthe impossibility to have a unique/universal equation. This study also showed that new RMR prediction equations must bedeveloped for specific populations taking into consideration the race and where the individual resides.

  14. Are People Responsive to a More Sustainable, Decentralized, and User-Driven Management of Urban Metabolism?

    Directory of Open Access Journals (Sweden)

    Lorenzo Chelleri

    2016-03-01

    Full Text Available Smart, green, and resilient city paradigms have been mainly promoted through top-down and technocratic approaches. However, based on the notion to return to “the right to the city”, emerging community-driven initiatives are providing self-managed infrastructures contributing to urban sustainability transitions. This paper explores the relevance of the behavioral aspects of people-centered approaches in dealing with two different facets of urban metabolism: physical infrastructure (involvement with the management of decentralized infrastructures and consumption patterns (involvement in proactive reduction of resources used. In the first case we assessed community perceptions about the roles, benefits, and willingness to proactively engage in the management of decentralized green infrastructures in Bogotá City, Colombia. For the second facet, we measured the effectiveness of change agents in re-shaping energy consumption decisions within urban social networks in South Africa and Saudi Arabia. This paper’s results show that pre-determined and standardized strategies do not guarantee positive, nor homogeneous, results in terms of meeting sustainability targets, or promoting community involvement. Hence, a better integration of people-centered and top-down approaches is needed through context-dependent policies, for enhancing both users’ appreciation of and commitment to urban metabolism participative management.

  15. Why mammalian lineages respond differently to sexual selection: metabolic rate constrains the evolution of sperm size.

    Science.gov (United States)

    Gomendio, Montserrat; Tourmente, Maximiliano; Roldan, Eduardo R S

    2011-10-22

    The hypothesis that sperm competition should favour increases in sperm size, because it results in faster swimming speeds, has received support from studies on many taxa, but remains contentious for mammals. We suggest that this may be because mammalian lineages respond differently to sexual selection, owing to major differences in body size, which are associated with differences in mass-specific metabolic rate. Recent evidence suggests that cellular metabolic rate also scales with body size, so that small mammals have cells that process energy and resources from the environment at a faster rate. We develop the 'metabolic rate constraint hypothesis' which proposes that low mass-specific metabolic rate among large mammals may limit their ability to respond to sexual selection by increasing sperm size, while this constraint does not exist among small mammals. Here we show that among rodents, which have high mass-specific metabolic rates, sperm size increases under sperm competition, reaching the longest sperm sizes found in eutherian mammals. By contrast, mammalian lineages with large body sizes have small sperm, and while metabolic rate (corrected for body size) influences sperm size, sperm competition levels do not. When all eutherian mammals are analysed jointly, our results suggest that as mass-specific metabolic rate increases, so does maximum sperm size. In addition, species with low mass-specific metabolic rates produce uniformly small sperm, while species with high mass-specific metabolic rates produce a wide range of sperm sizes. These findings support the hypothesis that mass-specific metabolic rates determine the budget available for sperm production: at high levels, sperm size increases in response to sexual selection, while low levels constrain the ability to respond to sexual selection by increasing sperm size. Thus, adaptive and costly traits, such as sperm size, may only evolve under sexual selection when metabolic rate does not constrain cellular

  16. Elevational variation in adult body size and growth rate but not in metabolic rate in the tree weta Hemideina crassidens.

    Science.gov (United States)

    Bulgarella, Mariana; Trewick, Steven A; Godfrey, A Jonathan R; Sinclair, Brent J; Morgan-Richards, Mary

    2015-04-01

    Populations of the same species inhabiting distinct localities experience different ecological and climatic pressures that might result in differentiation in traits, particularly those related to temperature. We compared metabolic rate (and its thermal sensitivity), growth rate, and body size among nine high- and low-elevation populations of the Wellington tree weta, Hemideina crassidens, distributed from 9 to 1171 m a.s.l across New Zealand. Our results did not indicate elevational compensation in metabolic rates (metabolic cold adaptation). Cold acclimation decreased metabolic rate compared to warm-acclimated individuals from both high- and low-elevation populations. However, we did find countergradient variation in growth rates, with individuals from high-elevation populations growing faster and to a larger final size than individuals from low-elevation populations. Females grew faster to a larger size than males, although as adults their metabolic rates did not differ significantly. The combined physiological and morphological data suggest that high-elevation individuals grow quickly and achieve larger size while maintaining metabolic rates at levels not significantly different from low-elevation individuals. Thus, morphological differentiation among tree weta populations, in concert with genetic variation, might provide the material required for adaptation to changing conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Modeling analysis of the benefits of Crassulacean acid metabolism (CAM) for sustainable agriculture in arid regions

    Science.gov (United States)

    Bartlett, M. S.; Vico, G.; Porporato, A. M.

    2012-12-01

    In view of the pressing needs to sustainably manage water and soil resources, especially in arid and semi-arid regions, here we propose a new carbon assimilation model that couples a simple yet mechanistic description of Crassulacean acid metabolism (CAM) photosynthesis to the soil-plant-atmosphere continuum. The model captures the full coupling of the CAM photosynthetic pathway with fluctuations in environmental conditions (cycles of light availability and air humidity, changes in soil moisture as driven by plant transpiration and rainfall occurrence). As such, the model is capable of reproducing the different phases of CAM, including daytime stomatal closure and photosynthesis from malic acid, afternoon stomatal opening for direct carbon assimilation, and nighttime stomatal opening for CO2 uptake and malic acid synthesis. Thanks to its versatility, our model allows us to relate CAM productivity, for both obligate and facultative CAM plants, to various soil moisture conditions including hydroclimatic scenarios of rainfall frequency and intensity as well as different night-time conditions of temperature, wind speed, and humidity. Our analyses show the potential productive benefits of CAM cultivation in dryland environments as feedstock and possible biofuel source, in terms of sustainable water use and economic benefits. In particular, the model is used to explore conditions where CAM plant resiliency to water stress makes these plants a more sustainable alternative to C3 and C4 species for potential deficit irrigation.

  18. Effects of body lipid content on the resting metabolic rate and postprandial metabolic response in the southern catfish Silurus meridionalis.

    Science.gov (United States)

    Luo, Yiping; Xie, Xiaojun

    2009-12-01

    We assessed the effects of body lipid content on the resting metabolic rate and specific dynamic action (SDA) of the southern catfish Silurus meridionalis. Obese and lean fish were obtained by feeding the fish with two different feeds at 27.5 degrees C for 4 weeks prior to the experiment. The fish were fed with experimental diets with a meal size of 4% by body mass. A continuous-flow respirometer was used to determine the oxygen consumption rate at 2-h intervals until the postprandial oxygen consumption rate had returned to the preprandial level. The body lipid content of the obese fish was significantly greater than that of the lean fish. The metabolic parameters evaluated (resting metabolic rate, peak metabolic rate (R(peak)), factorial ratio, time to peak, duration, energy expended on SDA (SDA(E)), or SDA coefficient) were not significantly affected by body fat content in terms of the whole-body or mass-specific values. Increased body fat content did not decrease the resting metabolic rate in the southern catfish, which might be due to the higher levels of highly unsaturated fatty acids in these fish. The results also suggest that the body composition does not appear to affect the SDA response.

  19. Metabolic rate and evaporative water loss of Mexican Spotted and Great Horned Owls

    Science.gov (United States)

    Joseph L. Ganey; Russell P. Balda; Rudy M. King

    1993-01-01

    We measured rates of oxygen consumption and evaporative water loss (EWL) of Mexican Spotted (Strix occidentalis lucida) and Great Horned (Bubo virginianus) owls in Arizona. Basal metabolic rate averaged 0.84 ccO2. g-1. h-1...

  20. Exercise-induced maximum metabolic rate scaled to body mass by ...

    African Journals Online (AJOL)

    The central postulation of the present approach to metabolic rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is proportional to the fractal extent (V) of an animal. Total fractal extent can be calculated from the sum of the fractal extents of the capillary service units, as specified by the formula V ...

  1. Heart rate variability and the metabolic syndrome: a systematic review of the literature.

    Science.gov (United States)

    Stuckey, Melanie I; Tulppo, Mikko P; Kiviniemi, Antti M; Petrella, Robert J

    2014-11-01

    A number of cross-sectional studies have examined associations between heart rate variability and metabolic syndrome, but differences in study populations, data collection and analysis methodologies make synthesis difficult. The purpose of this study was to systematically review published primary research examining associations between heart rate variability and metabolic syndrome or its individual risk factors. A systematic literature search of PubMed and EMBASE was conducted to identify relevant articles published from January 1999 to December 2012. Studies were included if they examined associations between heart rate variability analysed by standard protocols and metabolic syndrome risk factors according to published definitions. All papers were scored with a modified Downs and Black instrument, and data were extracted. Fourteen studies were included. Heart rate variability generally was reduced in women with metabolic syndrome compared to those without, while results in men were inconsistent. Time and frequency domain heart rate variability parameters were associated with individual metabolic syndrome risk factors, though sex differences exist. Only two studies considered nonlinear and Poincaré plot heart rate variability parameters, which were reduced in metabolic syndrome. Heart rate variability is altered differently in men and women with metabolic syndrome. Future studies should follow consistent heart rate variability analysis protocols and metabolic syndrome definitions and include more comprehensive analyses to investigate potential mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.

  2. Thyroid hormones correlate with resting metabolic rate, not daily energy expenditure, in two charadriiform seabirds

    Directory of Open Access Journals (Sweden)

    Kyle H. Elliott

    2013-04-01

    Thyroid hormones affect in vitro metabolic intensity, increase basal metabolic rate (BMR in the lab, and are sometimes correlated with basal and/or resting metabolic rate (RMR in a field environment. Given the difficulty of measuring metabolic rate in the field—and the likelihood that capture and long-term restraint necessary to measure metabolic rate in the field jeopardizes other measurements—we examined the possibility that circulating thyroid hormone levels were correlated with RMR in two free-ranging bird species with high levels of energy expenditure (the black-legged kittiwake, Rissa tridactyla, and thick-billed murre, Uria lomvia. Because BMR and daily energy expenditure (DEE are purported to be linked, we also tested for a correlation between thyroid hormones and DEE. We examined the relationships between free and bound levels of the thyroid hormones thyroxine (T4 and triiodothyronine (T3 with DEE and with 4-hour long measurements of post-absorptive and thermoneutral resting metabolism (resting metabolic rate; RMR. RMR but not DEE increased with T3 in both species; both metabolic rates were independent of T4. T3 and T4 were not correlated with one another. DEE correlated with body mass in kittiwakes but not in murres, presumably owing to the larger coefficient of variation in body mass during chick rearing for the more sexually dimorphic kittiwakes. We suggest T3 provides a good proxy for resting metabolism but not DEE in these seabird species.

  3. Impact of a Metabolic Screening Bundle on Rates of Screening for Metabolic Syndrome in a Psychiatry Resident Outpatient Clinic

    Science.gov (United States)

    Wiechers, Ilse R.; Viron, Mark; Stoklosa, Joseph; Freudenreich, Oliver; Henderson, David C.; Weiss, Anthony

    2012-01-01

    Objective: Although it is widely acknowledged that second-generation antipsychotics are associated with cardiometabolic side effects, rates of metabolic screening have remained low. The authors created a quality-improvement (QI) intervention in an academic medical center outpatient psychiatry resident clinic with the aim of improving rates of…

  4. Metabolism correlates with variation in post-natal growth rate among songbirds at three latitudes

    Science.gov (United States)

    Ton, Riccardo; Martin, Thomas E.

    2016-01-01

    1. Variation in post-natal growth rates is substantial among organisms and especially strong among latitudes because tropical and south temperate species typically have slower growth than north temperate relatives. Metabolic rate is thought to be a critical mechanism underlying growth rates after accounting for allometric effects of body mass. However, comparative tests on a large spatial scale are lacking, and the importance of metabolism for growth rates remains unclear both within and particularly across latitudes.

  5. Sustainable source of omega-3 eicosapentaenoic acid from metabolically engineered Yarrowia lipolytica: from fundamental research to commercial production.

    Science.gov (United States)

    Xie, Dongming; Jackson, Ethel N; Zhu, Quinn

    2015-02-01

    The omega-3 fatty acids, cis-5, 8, 11, 14, and 17-eicosapentaenoic acid (C20:5; EPA) and cis-4, 7, 10, 13, 16, and 19-docosahexaenoic acid (C22:6; DHA), have wide-ranging benefits in improving heart health, immune function, mental health, and infant cognitive development. Currently, the major source for EPA and DHA is from fish oil, and a minor source of DHA is from microalgae. With the increased demand for EPA and DHA, DuPont has developed a clean and sustainable source of the omega-3 fatty acid EPA through fermentation using metabolically engineered strains of Yarrowia lipolytica. In this mini-review, we will focus on DuPont's technology for EPA production. Specifically, EPA biosynthetic and supporting pathways have been introduced into the oleaginous yeast to synthesize and accumulate EPA under fermentation conditions. This Yarrowia platform can also produce tailored omega-3 (EPA, DHA) and/or omega-6 (ARA, GLA) fatty acid mixtures in the cellular lipid profiles. Fundamental research such as metabolic engineering for strain construction, high-throughput screening for strain selection, fermentation process development, and process scale-up were all needed to achieve the high levels of EPA titer, rate, and yield required for commercial application. Here, we summarize how we have combined the fundamental bioscience and the industrial engineering skills to achieve large-scale production of Yarrowia biomass containing high amounts of EPA, which led to two commercial products, New Harvest™ EPA oil and Verlasso® salmon.

  6. Carbon conversion and metabolic rate in two marine sponges

    NARCIS (Netherlands)

    Koopmans, M.; Rijswijk, van P.; Martens, D.E.; Egorova-Zachernyuk, T.A.; Middelburg, J.J.; Wijffels, R.H.

    2011-01-01

    The carbon metabolism of two marine sponges, Haliclona oculata and Dysidea avara, has been studied using a 13C isotope pulse-chase approach. The sponges were fed 13C-labeled diatoms (Skeletonema costatum) for 8 h and they took up between 75 and 85%. At different times, sponges were sampled for total

  7. Survival under stress: molecular mechanisms of metabolic rate ...

    African Journals Online (AJOL)

    Studies in my laboratory are analysing the molecular mechanisms and regulatory events that underlie transitions to and from hypometabolic states In systems including ... Our newest research targets two areas: the role of protein kinases in regulating metabolic adjustments and the role of stress-induced gene expression in ...

  8. Thermal sensation and comfort with transient metabolic rates

    DEFF Research Database (Denmark)

    Goto, Tomonobu; Toftum, Jørn; Dear, R. d.

    2002-01-01

    This study investigated the effect on thermal perceptions and preferences of controlled metabolic excursions of various intensities (20%, 40%, 60% relative work load) and durations (3-30 min) imposed on subjects that alternated between sedentary activity and exercise on a treadmill. The thermal...

  9. Individuals exhibit consistent differences in their metabolic rates across changing thermal conditions.

    Science.gov (United States)

    Auer, Sonya K; Salin, Karine; Anderson, Graeme J; Metcalfe, Neil B

    2018-03-01

    Metabolic rate has been linked to growth, reproduction, and survival at the individual level and is thought to have far reaching consequences for the ecology and evolution of organisms. However, metabolic rates must be consistent (i.e. repeatable) over at least some portion of the lifetime in order to predict their longer-term effects on population dynamics and how they will respond to selection. Previous studies demonstrate that metabolic rates are repeatable under constant conditions but potentially less so in more variable environments. We measured the standard (=minimum) metabolic rate, maximum metabolic rate, and aerobic scope (=interval between standard and maximum rates) in juvenile brown trout (Salmo trutta) after 5weeks acclimation to each of three consecutive test temperatures (10, 13, and then 16°C) that simulated the warming conditions experienced throughout their first summer of growth. We found that metabolic rates are repeatable over a period of months under changing thermal conditions: individual trout exhibited consistent differences in all three metabolic traits across increasing temperatures. Initial among-individual differences in metabolism are thus likely to have significant consequences for fitness-related traits over key periods of their life history. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Compare the resting metabolic rate status in the healthy metabolically obese with the unhealthy metabolically obese participants

    Directory of Open Access Journals (Sweden)

    Banafshe Hosseini

    2016-12-01

    Conclusion: In this study we did not observe any major effects of RMR on metabolic health criteria except for the HOMA. Further studies are needed to investigate the effects of RMR on glucose abnormalities that may lead to modify cardio-metabolic criteria.

  11. Concentrations, metabolic clearance rates, production rates and plasma binding of cortisol in Antarctic phocid seals.

    Science.gov (United States)

    Liggins, G C; France, J T; Schneider, R C; Knox, B S; Zapol, W M

    1993-10-01

    We have reported previously that plasma of the Weddell seal, a member of the phocid family, contains a very high concentration of cortisol. The present study was undertaken to determine whether high cortisol levels were common to seals in the Antarctic environment, or to other phocidae, and to determine the mechanism of the hypercortisolaemia. High levels of cortisol (0.82-2.38 mumol/l) were found in 4 phocidae (Weddell, crabeater, leopard and Southern elephant seals), whereas levels in a member of the otariid family (Antarctic fur seal) were similar to human values. Metabolic clearance rates (MCR) and production rates (PR) of cortisol were determined in the field in Weddell (N = 1), crabeater (N = 3) and leopard (N = 3) seals following bolus injections of [3H] cortisol. The MCR and PR did not differ between the three phocids, but whereas the MCR of 410-590 1/day was twice that of human values, the PR of 460-1180 mumol.m-2 x d-1 was up to 40-fold greater. The binding capacity of corticosteroid-binding globulin (CBG) was equal to or greater than the plasma concentrations of cortisol, resulting in relatively low concentrations of free cortisol. We conclude that hypercortisolaemia is maintained in phocid seals mainly by a high production rate--the highest (corrected for surface area) reported in any species. The relatively low cortisol levels in otariid seals studied in the same environment suggest that the high PR in phocidae is unrelated to the harsh climatic conditions, but may be part of their adaptation for diving to extreme depths.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Ontogeny of metabolic rate and red blood cell size in eyelid geckos: species follow different paths.

    Directory of Open Access Journals (Sweden)

    Zuzana Starostová

    Full Text Available While metabolism is a fundamental feature of all organisms, the causes of its scaling with body mass are not yet fully explained. Nevertheless, observations of negative correlations between red blood cell (RBC size and the rate of metabolism suggest that size variation of these cells responsible for oxygen supply may play a crucial role in determining metabolic rate scaling in vertebrates. Based on a prediction derived from the Cell Metabolism Hypothesis, metabolic rate should increase linearly with body mass in species with RBC size invariance, and slower than linearly when RBC size increases with body mass. We found support for that prediction in five species of eyelid geckos (family Eublepharidae with different patterns of RBC size variation during ontogenetic growth. During ontogeny, metabolic rate increases nearly linearly with body mass in those species of eyelid geckos where there is no correlation between RBC size and body mass, whereas non-linearity of metabolic rate scaling is evident in those species with ontogenetic increase of RBC size. Our findings provide evidence that ontogenetic variability in RBC size, possibly correlating with sizes of other cell types, could have important physiological consequences and can contribute to qualitatively different shape of the intraspecific relationship between metabolic rate and body mass.

  13. Uncinate Process Length in Birds Scales with Resting Metabolic Rate

    OpenAIRE

    Peter Tickle; Robert Nudds; Jonathan Codd

    2009-01-01

    A fundamental function of the respiratory system is the supply of oxygen to meet metabolic demand. Morphological constraints on the supply of oxygen, such as the structure of the lung, have previously been studied in birds. Recent research has shown that uncinate processes (UP) are important respiratory structures in birds, facilitating inspiratory and expiratory movements of the ribs and sternum. Uncinate process length (UPL) is important for determining the mechanical advantage for these re...

  14. Lake Metabolism: Comparison of Lake Metabolic Rates Estimated from a Diel CO2- and the Common Diel O2-Technique.

    Directory of Open Access Journals (Sweden)

    Frank Peeters

    Full Text Available Lake metabolism is a key factor for the understanding of turnover of energy and of organic and inorganic matter in lake ecosystems. Long-term time series on metabolic rates are commonly estimated from diel changes in dissolved oxygen. Here we present long-term data on metabolic rates based on diel changes in total dissolved inorganic carbon (DIC utilizing an open-water diel CO2-technique. Metabolic rates estimated with this technique and the traditional diel O2-technique agree well in alkaline Lake Illmensee (pH of ~8.5, although the diel changes in molar CO2 concentrations are much smaller than those of the molar O2 concentrations. The open-water diel CO2- and diel O2-techniques provide independent measures of lake metabolic rates that differ in their sensitivity to transport processes. Hence, the combination of both techniques can help to constrain uncertainties arising from assumptions on vertical fluxes due to gas exchange and turbulent diffusion. This is particularly important for estimates of lake respiration rates because these are much more sensitive to assumptions on gradients in vertical fluxes of O2 or DIC than estimates of lake gross primary production. Our data suggest that it can be advantageous to estimate respiration rates assuming negligible gradients in vertical fluxes rather than including gas exchange with the atmosphere but neglecting vertical mixing in the water column. During two months in summer the average lake net production was close to zero suggesting at most slightly autotrophic conditions. However, the lake emitted O2 and CO2 during the entire time period suggesting that O2 and CO2 emissions from lakes can be decoupled from the metabolism in the near surface layer.

  15. Lake Metabolism: Comparison of Lake Metabolic Rates Estimated from a Diel CO2- and the Common Diel O2-Technique.

    Science.gov (United States)

    Peeters, Frank; Atamanchuk, Dariia; Tengberg, Anders; Encinas-Fernández, Jorge; Hofmann, Hilmar

    2016-01-01

    Lake metabolism is a key factor for the understanding of turnover of energy and of organic and inorganic matter in lake ecosystems. Long-term time series on metabolic rates are commonly estimated from diel changes in dissolved oxygen. Here we present long-term data on metabolic rates based on diel changes in total dissolved inorganic carbon (DIC) utilizing an open-water diel CO2-technique. Metabolic rates estimated with this technique and the traditional diel O2-technique agree well in alkaline Lake Illmensee (pH of ~8.5), although the diel changes in molar CO2 concentrations are much smaller than those of the molar O2 concentrations. The open-water diel CO2- and diel O2-techniques provide independent measures of lake metabolic rates that differ in their sensitivity to transport processes. Hence, the combination of both techniques can help to constrain uncertainties arising from assumptions on vertical fluxes due to gas exchange and turbulent diffusion. This is particularly important for estimates of lake respiration rates because these are much more sensitive to assumptions on gradients in vertical fluxes of O2 or DIC than estimates of lake gross primary production. Our data suggest that it can be advantageous to estimate respiration rates assuming negligible gradients in vertical fluxes rather than including gas exchange with the atmosphere but neglecting vertical mixing in the water column. During two months in summer the average lake net production was close to zero suggesting at most slightly autotrophic conditions. However, the lake emitted O2 and CO2 during the entire time period suggesting that O2 and CO2 emissions from lakes can be decoupled from the metabolism in the near surface layer.

  16. Inbreeding effects on standard metabolic rate investigated at cold, benign and hot temperatures in Drosophila melanogaster.

    Science.gov (United States)

    Jensen, Palle; Overgaard, Johannes; Loeschcke, Volker; Schou, Mads Fristrup; Malte, Hans; Kristensen, Torsten Nygaard

    2014-03-01

    Inbreeding increases homozygosity, which is known to affect the mean and variance of fitness components such as growth, fecundity and mortality rate. Across inbred lines inbreeding depression is typically observed and the variance between lines is increased in inbred compared to outbred lines. It has been suggested that damage incurred from increased homozygosity entails energetic cost associated with cellular repair. However, little is known about the effects of inbreeding on standard metabolic rate. Using stop-flow respirometry we performed repeated measurements of metabolic rate in replicated lines of inbred and outbred Drosophila melanogaster at stressful low, benign and stressful high temperatures. The lowest measurements of metabolic rate in our study are always associated with the low activity period of the diurnal cycle and these measurements therefore serve as good estimates of standard metabolic rate. Due to the potentially added costs of genetic stress in inbred lines we hypothesized that inbred individuals have increased metabolic rate compared to outbred controls and that this is more pronounced at stressful temperatures due to synergistic inbreeding by environment interactions. Contrary to our hypothesis we found no significant difference in metabolic rate between inbred and outbred lines and no interaction between inbreeding and temperature. Inbreeding however effected the variance; the variance in metabolic rate was higher between the inbred lines compared to the outbred control lines with some inbred lines having very high or low standard metabolic rate. Thus genetic drift and not inbreeding per se seem to explain variation in metabolic rate in populations of different size. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Dedicated Industrial Oilseed Crops as Metabolic Engineering Platforms for Sustainable Industrial Feedstock Production

    Science.gov (United States)

    Zhu, Li-Hua; Krens, Frans; Smith, Mark A.; Li, Xueyuan; Qi, Weicong; van Loo, Eibertus N.; Iven, Tim; Feussner, Ivo; Nazarenus, Tara J.; Huai, Dongxin; Taylor, David C.; Zhou, Xue-Rong; Green, Allan G.; Shockey, Jay; Klasson, K. Thomas; Mullen, Robert T.; Huang, Bangquan; Dyer, John M.; Cahoon, Edgar B.

    2016-01-01

    Feedstocks for industrial applications ranging from polymers to lubricants are largely derived from petroleum, a non-renewable resource. Vegetable oils with fatty acid structures and storage forms tailored for specific industrial uses offer renewable and potentially sustainable sources of petrochemical-type functionalities. A wide array of industrial vegetable oils can be generated through biotechnology, but will likely require non-commodity oilseed platforms dedicated to specialty oil production for commercial acceptance. Here we show the feasibility of three Brassicaceae oilseeds crambe, camelina, and carinata, none of which are widely cultivated for food use, as hosts for complex metabolic engineering of wax esters for lubricant applications. Lines producing wax esters >20% of total seed oil were generated for each crop and further improved for high temperature oxidative stability by down-regulation of fatty acid polyunsaturation. Field cultivation of optimized wax ester-producing crambe demonstrated commercial utility of these engineered crops and a path for sustainable production of other industrial oils in dedicated specialty oilseeds. PMID:26916792

  18. Dedicated Industrial Oilseed Crops as Metabolic Engineering Platforms for Sustainable Industrial Feedstock Production.

    Science.gov (United States)

    Zhu, Li-Hua; Krens, Frans; Smith, Mark A; Li, Xueyuan; Qi, Weicong; van Loo, Eibertus N; Iven, Tim; Feussner, Ivo; Nazarenus, Tara J; Huai, Dongxin; Taylor, David C; Zhou, Xue-Rong; Green, Allan G; Shockey, Jay; Klasson, K Thomas; Mullen, Robert T; Huang, Bangquan; Dyer, John M; Cahoon, Edgar B

    2016-02-26

    Feedstocks for industrial applications ranging from polymers to lubricants are largely derived from petroleum, a non-renewable resource. Vegetable oils with fatty acid structures and storage forms tailored for specific industrial uses offer renewable and potentially sustainable sources of petrochemical-type functionalities. A wide array of industrial vegetable oils can be generated through biotechnology, but will likely require non-commodity oilseed platforms dedicated to specialty oil production for commercial acceptance. Here we show the feasibility of three Brassicaceae oilseeds crambe, camelina, and carinata, none of which are widely cultivated for food use, as hosts for complex metabolic engineering of wax esters for lubricant applications. Lines producing wax esters >20% of total seed oil were generated for each crop and further improved for high temperature oxidative stability by down-regulation of fatty acid polyunsaturation. Field cultivation of optimized wax ester-producing crambe demonstrated commercial utility of these engineered crops and a path for sustainable production of other industrial oils in dedicated specialty oilseeds.

  19. Metabolic states with maximal specific rate carry flux through an elementary flux mode.

    NARCIS (Netherlands)

    Wortel, M.T.; Peters, H; Hulshof, J.; Teusink, B.; Bruggeman, F.J.

    2014-01-01

    Specific product formation rates and cellular growth rates are important maximization targets in biotechnology and microbial evolution. Maximization of a specific rate (i.e. a rate expressed per unit biomass amount) requires the expression of particular metabolic pathways at optimal enzyme

  20. Individual variation in metabolic reaction norms over ambient temperature causes low correlation between basal and standard metabolic rate.

    Science.gov (United States)

    Briga, Michael; Verhulst, Simon

    2017-09-15

    Basal metabolic rate (BMR) is often assumed to be indicative of the energy turnover at ambient temperatures ( T a ) below the thermoneutral zone (SMR), but this assumption has remained largely untested. Using a new statistical approach, we quantified the consistency in nocturnal metabolic rate across a temperature range in zebra finches ( N =3213 measurements on 407 individuals) living permanently in eight outdoor aviaries. Foraging conditions were either benign or harsh, and body mass and mass-adjusted BMR (BMR m ) and SMR (SMR m ) were lower in individuals living in a harsh foraging environment. The correlation between SMR m at different T a was high ( r =0.91), independent of foraging environment, showing that individuals are consistently ranked according to their SMR m However, the correlations between BMR m and SMR m were always lower (average: r =0.29; range: 0metabolic response to lower T a at least in part reflected differential body temperature ( T b ) regulation: early morning T b was lower at low T a , and more so in individuals with a weaker metabolic response to lower T a Our findings have implications for the use of BMR in the estimation of time-energy budgets and comparative analyses: we suggest that the use of metabolic rates at ecologically relevant T a , such as the easily tractable SMR, will be more informative than the use of BMR as a proxy for energy turnover. © 2017. Published by The Company of Biologists Ltd.

  1. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  2. Critical review of LEED system for rating sustainability of architecture of commercial interiors

    Directory of Open Access Journals (Sweden)

    Stevanović Sanja

    2010-01-01

    Full Text Available The LEED rating system for sustainability of architecture has gained large marketing potential in USA and became one of main ways American builders are attacking ecological challenges. In this paper the LEED rating system for commercial interiors is critically reviewed, pointing out its positive - focus on integrated design process - and negative impacts - low thresholds for highest ratings and tendency to gain LEED rating with projects that hardly pass the thresholds, largely neglecting the principles of energy efficiency. Based on a few prominent LEED platinum examples, the beginnings of a LEED style of designing interiors in historical landmark buildings are pointed out as well.

  3. The absorption and metabolism of a single L-menthol oral versus skin administration: Effects on thermogenesis and metabolic rate.

    Science.gov (United States)

    Valente, Angelica; Carrillo, Andres E; Tzatzarakis, Manolis N; Vakonaki, Elena; Tsatsakis, Aristidis M; Kenny, Glen P; Koutedakis, Yiannis; Jamurtas, Athanasios Z; Flouris, Andreas D

    2015-12-01

    We investigated the absorption and metabolism pharmacokinetics of a single L-menthol oral versus skin administration and the effects on human thermogenesis and metabolic rate. Twenty healthy adults were randomly distributed into oral (capsule) and skin (gel) groups and treated with 10 mg kg(-1) L-menthol (ORALMENT; SKINMENT) or control (lactose capsule: ORALCON; water application: SKINCON) in a random order on two different days. Levels of serum L-menthol increased similarly in ORALMENT and SKINMENT (p > 0.05). L-menthol glucuronidation was greater in ORALMENT than SKINMENT (p  0.05). Participants reported no cold, shivering, discomfort, stress or skin irritation. We conclude that a single L-menthol skin administration increased thermogenesis and metabolic rate in humans. These effects are minor following L-menthol oral administration probably due to faster glucuronidation and greater blood menthol glucuronide levels. Copyright © 2015. Published by Elsevier Ltd.

  4. Sustained release nitrite therapy results in myocardial protection in a porcine model of metabolic syndrome with peripheral vascular disease

    OpenAIRE

    Bradley, Jessica M.; Islam, Kazi N.; Polhemus, David J.; Donnarumma, Erminia; Brewster, Luke P.; Tao, Ya-Xiong; Goodchild, Traci T.; Lefer, David J.

    2015-01-01

    In a clinically relevant porcine model of metabolic syndrome and peripheral vascular disease, treatment with a novel sustained-release nitrite formulation restored cardiac endothelial nitric oxide synthase, enhancing myocardial nitrite levels, reduced oxidative stress, and improved ex vivo coronary vascular function via endothelium-independent vasodilation mechanism in obese Ossabaw swine.

  5. Cold climate specialization: adaptive covariation between metabolic rate and thermoregulation in pregnant vipers.

    Science.gov (United States)

    Lourdais, Olivier; Guillon, Michaël; Denardo, Dale; Blouin-Demers, Gabriel

    2013-07-02

    We compared thermoregulatory strategies during pregnancy in two congeneric viperid snakes (Vipera berus and Vipera aspis) with parapatric geographic ranges. V. berus is a boreal specialist with the largest known distribution among terrestrial snakes while V. aspis is a south-European species. Despite contrasted climatic affinities, the two species displayed identical thermal preferences (Tset) in a laboratory thermal gradient. Under identical natural conditions, however, V. berus was capable of maintaining Tset for longer periods, especially when the weather was constraining. Consistent with the metabolic cold adaptation hypothesis, V. berus displayed higher standard metabolic rate at all temperatures considered. We used the thermal dependence of metabolic rate to calculate daily metabolic profiles from body temperature under natural conditions. The boreal specialist experienced higher daily metabolic rate and minimized gestation duration chiefly because of differences in the metabolic reaction norms, but also superior thermoregulatory efficiency. Under cold climates, thermal constraints should make precise thermoregulation costly. However, a shift in the metabolic reaction norm may compensate for thermal constraints and modify the cost-benefit balance of thermoregulation. Covariation between metabolic rate and thermoregulation efficiency is likely an important adaptation to cold climates. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Sustainable usability rating system for shopping centres; Kauppakeskusten kestaevaen kaeytettaevyyden arviointi

    Energy Technology Data Exchange (ETDEWEB)

    Nissinen, K.; Mottonen, V.; Niemi, R.; Nenonen, S.; Alho, J.

    2012-08-15

    The aim of this study was to create a sustainable usability rating system for shopping centers. The system consists out of seven main factors divided into 80 sub factors. The main factors are: location and accessibility, technical characteristics of the real estate, energy efficiency, waste management and recycling efficiency, tenant mix sustainability, economic prerequisites for tenant business operations and responsible shopping center management. Each of the factors has its own weighting when calculating the total score. Some of the criteria are quantitative some qualitative. The scoring system is equal to opinion score system used in Finnish schools (4-10). The rating system was tested in five large scale shopping centers. Among the rated centers the total score varied from 7.3 to 7.9 and the average score was 7.6. (orig.)

  7. The performance advantage of a high resting metabolic rate in juvenile salmon is habitat dependent

    National Research Council Canada - National Science Library

    Reid, Donald; Armstrong, John D; Metcalfe, Neil B

    2012-01-01

    .... Resting metabolic rate (RMR) in juvenile salmon and trout is positively related to dominance status and ability to obtain a feeding territory, but it is not clear how this translates into performance in natural conditions. 2...

  8. Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr. (Univ. of California, Irvine (USA)); Gillin, J.C. (Univ. of California, San Diego (USA))

    1989-01-01

    The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increase in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep.

  9. Cross-validation of recent and longstanding resting metabolic rate prediction equations

    Science.gov (United States)

    Resting metabolic rate (RMR) measurement is time consuming and requires specialized equipment. Prediction equations provide an easy method to estimate RMR; however, their accuracy likely varies across individuals. Understanding the factors that influence predicted RMR accuracy at the individual lev...

  10. Cold- and Exercise-Induced Peak Metabolic Rates in Tropical Birds

    National Research Council Canada - National Science Library

    Popko Wiersma; Mark A. Chappell; Joseph B. Williams

    2007-01-01

    ...." To test predictions from this hypothesis, we measured exercise-induced peak metabolic rates in 45 species of tropical lowland forest birds and compared these data with for three temperate species...

  11. Quality Sleep Is Associated With Overnight Metabolic Rate in Healthy Older Adults.

    Science.gov (United States)

    Valenti, Giulio; Bonomi, Alberto G; Westerterp, Klaas R

    2017-04-01

    Increasing age is associated with an increase in overnight metabolic rate. To determine the relationship between quality sleep, sleep efficiency, and overnight metabolic rate as measured in a respiration chamber in older participants. The study design was cross sectional. Forty participants, aged 50 to 83 years (17 males, age 63±7 years, body mass index 25.7±2.3kg/m2) spent one night in a respiration chamber to measure sleep stages by polysomnography and overnight metabolic rate (OMR). Data were collected between 23:00 and 07:00. Subsequently basal metabolic rate (BMR) was measured under a ventilated hood. Quality sleep was calculated as time spent in rapid-eye movement (REM) sleep and slow wave sleep divided by total sleep time, and sleep efficiency was calculated as total sleep time divided by the sleep period time. Body movement was measured between 23:00 and 07:00 with an accelerometer on the wrist. Overnight metabolic rate was adjusted for body size by dividing by basal metabolic rate (OMR/BMR). OMR/BMR was positively associated with age (r = 0.48, p quality sleep was negatively associated with age (r = -0.51, p quality sleep (r = -0.58, p sleep efficiency (r = -0.38, pquality sleep, the effect of age was non significant. Quality sleep is inversely associated with the age-related rise in overnight metabolic rate, suggesting that increased overnight metabolic rate is a biological sign of ageing as a consequence of diminished quality sleep.

  12. Treatment of human muscle cells with popular dietary supplements increase mitochondrial function and metabolic rate

    Directory of Open Access Journals (Sweden)

    Vaughan Roger A

    2012-11-01

    Full Text Available Abstract Background Obesity is a common pathology with increasing incidence, and is associated with increased mortality and healthcare costs. Several treatment options for obesity are currently available ranging from behavioral modifications to pharmaceutical agents. Many popular dietary supplements claim to enhance weight loss by acting as metabolic stimulators, however direct tests of their effect on metabolism have not been performed. Purpose This work identified the effects popular dietary supplements on metabolic rate and mitochondrial biosynthesis in human skeletal muscle cells. Methods Human rhabdomyosarcoma cells were treated with popular dietary supplements at varied doses for 24 hours. Peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α, an important stimulator of mitochondrial biosynthesis, was quantified using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR. Mitochondrial content was measured using flow cytometry confirmed with confocal microscopy. Glycolytic metabolism was quantified by measuring extracellular acidification rate (ECAR and oxidative metabolism was quantified by measuring oxygen consumption rate (OCR. Total relative metabolism was quantified using WST-1 end point assay. Results Treatment of human rhabdomyosarcoma cells with dietary supplements OxyElite Pro (OEP or Cellucore HD (CHD induced PGC-1α leading to significantly increased mitochondrial content. Glycolytic and oxidative capacities were also significantly increased following treatment with OEP or CHD. Conclusion This is the first work to identify metabolic adaptations in muscle cells following treatment with popular dietary supplements including enhanced mitochondrial biosynthesis, and glycolytic, oxidative and total metabolism.

  13. Increased white matter metabolic rates in autism spectrum disorder and schizophrenia.

    Science.gov (United States)

    Mitelman, Serge A; Buchsbaum, Monte S; Young, Derek S; Haznedar, M Mehmet; Hollander, Eric; Shihabuddin, Lina; Hazlett, Erin A; Bralet, Marie-Cecile

    2017-11-22

    Both autism spectrum disorder (ASD) and schizophrenia are often characterized as disorders of white matter integrity. Multimodal investigations have reported elevated metabolic rates, cerebral perfusion and basal activity in various white matter regions in schizophrenia, but none of these functions has previously been studied in ASD. We used 18fluorodeoxyglucose positron emission tomography to compare white matter metabolic rates in subjects with ASD (n = 25) to those with schizophrenia (n = 41) and healthy controls (n = 55) across a wide range of stereotaxically placed regions-of-interest. Both subjects with ASD and schizophrenia showed increased metabolic rates across the white matter regions assessed, including internal capsule, corpus callosum, and white matter in the frontal and temporal lobes. These increases were more pronounced, more widespread and more asymmetrical in subjects with ASD than in those with schizophrenia. The highest metabolic increases in both disorders were seen in the prefrontal white matter and anterior limb of the internal capsule. Compared to normal controls, differences in gray matter metabolism were less prominent and differences in adjacent white matter metabolism were more prominent in subjects with ASD than in those with schizophrenia. Autism spectrum disorder and schizophrenia are associated with heightened metabolic activity throughout the white matter. Unlike in the gray matter, the vector of white matter metabolic abnormalities appears to be similar in ASD and schizophrenia, may reflect inefficient functional connectivity with compensatory hypermetabolism, and may be a common feature of neurodevelopmental disorders.

  14. Metabolic rate of the red panda, Ailurus fulgens, a dietary bamboo specialist.

    Directory of Open Access Journals (Sweden)

    Yuxiang Fei

    Full Text Available The red panda (Ailurus fulgens has a similar diet, primarily bamboo, and shares the same habitat as the giant panda, Ailuropoda melanoleuca. There are considerable efforts underway to understand the ecology of the red panda and to increase its populations in natural reserves. Yet it is difficult to design an effective strategy for red panda reintroduction if we do not understand its basic biology. Here we report the resting metabolic rate of the red panda and find that it is higher than previously measured on animals from a zoo. The resting metabolic rate was 0.290 ml/g/h (range 0.204-0.342 in summer and 0.361 ml/g/h in winter (range 0.331-0.406, with a statistically significant difference due to season and test temperature. Temperatures in summer were probably within the thermal neutral zone for metabolism but winter temperatures were below the thermal neutral zone. There was no difference in metabolic rate between male and female red pandas and no difference due to mass. Our values for metabolic rate were much higher than those measured by McNab for 2 red pandas from a zoo. The larger sample size (17, more natural conditions at the Panda Base and improved accuracy of the metabolic instruments provided more accurate metabolism measurements. Contrary to our expectations based on their low quality bamboo diet, the metabolic rates of red pandas were similar to mammals of the same size. Based on their metabolic rates red pandas would not be limited by their food supply in natural reserves.

  15. Racial differences in the relationship between rate of nicotine metabolism and nicotine intake from cigarette smoking.

    Science.gov (United States)

    Ross, Kathryn C; Gubner, Noah R; Tyndale, Rachel F; Hawk, Larry W; Lerman, Caryn; George, Tony P; Cinciripini, Paul; Schnoll, Robert A; Benowitz, Neal L

    2016-09-01

    Rate of nicotine metabolism has been identified as an important factor influencing nicotine intake and can be estimated using the nicotine metabolite ratio (NMR), a validated biomarker of CYP2A6 enzyme activity. Individuals who metabolize nicotine faster (higher NMR) may alter their smoking behavior to titrate their nicotine intake in order to maintain similar levels of nicotine in the body compared to slower nicotine metabolizers. There are known racial differences in the rate of nicotine metabolism with African Americans on average having a slower rate of nicotine metabolism compared to Whites. The goal of this study was to determine if there are racial differences in the relationship between rate of nicotine metabolism and measures of nicotine intake assessed using multiple biomarkers of nicotine and tobacco smoke exposure. Using secondary analyses of the screening data collected in a recently completed clinical trial, treatment-seeking African American and White daily smokers (10 or more cigarettes per day) were grouped into NMR quartiles so that the races could be compared at the same NMR, even though the distribution of NMR within race differed. The results indicated that rate of nicotine metabolism was a more important factor influencing nicotine intake in White smokers. Specifically, Whites were more likely to titrate their nicotine intake based on the rate at which they metabolize nicotine. However, this relationship was not found in African Americans. Overall there was a greater step-down, linear type relationship between NMR groups and cotinine or cotinine/cigarette in African Americans, which is consistent with the idea that differences in blood cotinine levels between the African American NMR groups were primarily due to differences in CYP2A6 enzyme activity without titration of nicotine intake among faster nicotine metabolizers. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Metabolic rate of the red panda, Ailurus fulgens, a dietary bamboo specialist.

    Science.gov (United States)

    Fei, Yuxiang; Hou, Rong; Spotila, James R; Paladino, Frank V; Qi, Dunwu; Zhang, Zhihe

    2017-01-01

    The red panda (Ailurus fulgens) has a similar diet, primarily bamboo, and shares the same habitat as the giant panda, Ailuropoda melanoleuca. There are considerable efforts underway to understand the ecology of the red panda and to increase its populations in natural reserves. Yet it is difficult to design an effective strategy for red panda reintroduction if we do not understand its basic biology. Here we report the resting metabolic rate of the red panda and find that it is higher than previously measured on animals from a zoo. The resting metabolic rate was 0.290 ml/g/h (range 0.204-0.342) in summer and 0.361 ml/g/h in winter (range 0.331-0.406), with a statistically significant difference due to season and test temperature. Temperatures in summer were probably within the thermal neutral zone for metabolism but winter temperatures were below the thermal neutral zone. There was no difference in metabolic rate between male and female red pandas and no difference due to mass. Our values for metabolic rate were much higher than those measured by McNab for 2 red pandas from a zoo. The larger sample size (17), more natural conditions at the Panda Base and improved accuracy of the metabolic instruments provided more accurate metabolism measurements. Contrary to our expectations based on their low quality bamboo diet, the metabolic rates of red pandas were similar to mammals of the same size. Based on their metabolic rates red pandas would not be limited by their food supply in natural reserves.

  17. Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods

    Science.gov (United States)

    Dubois, Romain; Paillard, Thierry; Lyons, Mark; McGrath, David; Maurelli, Olivier; Prioux, Jacques

    2017-01-01

    The aims of this study were (1) to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2) to explore the relationship between these methods and (3) to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y), over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax) were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; prugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high-intensity thresholds demonstrates that the metabolic power approach may represent an interesting alternative to the traditional approaches used in evaluating the high-intensity running efforts required in rugby union games. Key points Elite/professional rugby union players Heart rate monitoring during official games Metabolic power approach PMID:28344455

  18. Evaluation of rate of swelling and erosion of verapamil (VRP) sustained-release matrix tablets.

    Science.gov (United States)

    Khamanga, Sandile M; Walker, Roderick B

    2006-01-01

    Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.

  19. Is there a relationship between insect metabolic rate and mortality of mealworms Tenebrio molitor L. after insecticide exposure?

    OpenAIRE

    Justyna MALISZEWSKA; Eugenia TĘGOWSKA

    2016-01-01

    Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication with pyrethroid, oxadiazine, neonicotinoid and organophosphate. Metabolic rate before and after intoxic...

  20. Rate of Nicotine Metabolism and Withdrawal Symptoms in Adolescent Light Smokers

    Science.gov (United States)

    Rubinstein, Mark L.; Benowitz, Neal L.; Auerback, Glenna M.; Moscicki, Anna Barbara

    2009-01-01

    OBJECTIVES The rate of nicotine metabolism may contribute to vulnerability in adolescents’ transition from smoking initiation to addiction. The objectives of this study were to examine the associations between the rate of nicotine metabolism and cigarette consumption, addiction and withdrawal symptoms in a sample of adolescent light smokers. PARTICIPANTS Twenty adolescent smokers between 13 and 17 years-old, who smoked between 1 and 6 cigarettes daily for at least 6 months were recruited from several San Francisco Bay area schools and pediatric clinics from 2006–2007. METHODS Participants underwent 24 hours of supervised tobacco abstinence. Serum was collected at baseline and at 24 hours for measurement of the nicotine metabolites, cotinine and 3’-hydroxycotinine (3HC). Participants also completed self-report measures which included smoking behavior, nicotine dependence and withdrawal scales at baseline and 24 hours post baseline. The ratio of serum 3HC to cotinine (the nicotine metabolite ratio), a measure of the rate of nicotine metabolism, was computed using measurements from the 24 hour serum samples. RESULTS Participants were divided into two groups: faster metabolizers (3HC/Cotinine ratio ≥ 0.5; n=5) and slower metabolizers (3HC/Cotinine ratio < 0.5; n=15). Faster metabolizers reported greater withdrawal symptoms after 24 hours of abstinence compared with slower metabolizers even after adjusting for the number of cigarettes smoked per day (p=.03). The metabolite ratio was significantly correlated with self-described level of addiction (r=.50, p=.03). CONCLUSIONS This is the first study to report a significant relationship between the rate of nicotine metabolism and withdrawal symptoms and self-reported addiction in adolescent light smokers. Given the association between withdrawal symptoms and nicotine addiction, adolescent smokers who are faster metabolizers of nicotine may be at greater risk for becoming addicted to nicotine compared with slower

  1. Sustained attention and heart rate variability in children and adolescents with ADHD.

    Science.gov (United States)

    Griffiths, Kristi R; Quintana, Daniel S; Hermens, Daniel F; Spooner, Chris; Tsang, Tracey W; Clarke, Simon; Kohn, Michael R

    2017-03-01

    The autonomic nervous system (ANS) plays an important role in attention and self-regulation by modulating physiological arousal to meet environmental demands. Core symptoms of ADHD such as inattention and behavioral disinhibition may be related to dysregulation of the ANS, however previous findings have been equivocal. We examined autonomic activity and reactivity by assessing heart rate variability (HRV) in a large sample of un-medicated children and adolescents (6-19 years) with ADHD (n=229) compared to typically-developing controls (n=244) during rest and sustained attention. Four heart rate variability measures were extracted: Root mean square of successive differences between inter-beat-intervals (rMSSD), absolute high frequency (HFA) power, absolute low frequency (LFA) power and ratio of low frequency power to high frequency power (LF/HF). There were no group differences in HFA or rMSSD, even when assessing across child and adolescent groups separately, by gender or ADHD subtype. LF/HF however was higher in ADHD during both rest and sustained attention conditions, particularly in male children. Sustained attention was impaired in ADHD relative to controls, and a higher LF/HF ratio during sustained attention was associated with poorer performance in both groups. Lower rMSSD and HFA were associated with higher anxiety, oppositional behaviors and social problems, supporting prevailing theories that these measures index emotion regulation and adaptive social behavior. Different measures of heart rate variability provide important insights into the sustained attention and emotional and behavioral regulation impairments observed in ADHD and may aid in delineating ADHD pathophysiology. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Repeatability of standard metabolic rate, active metabolic rate and aerobic scope in young brown trout during a period of moderate food availability.

    Science.gov (United States)

    Norin, Tommy; Malte, Hans

    2011-05-15

    Standard metabolic rate (SMR) and active metabolic rate (AMR) are two fundamental physiological parameters providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available within these two parameters confines constitutes the absolute aerobic scope (AAS). Previous studies on fish have found SMR to closely correlate with dominance and position in the social hierarchy, and to be highly repeatable over time when fish were provided an ad libitum diet. In this study we tested the temporal repeatability of individual SMR, AMR and AAS, as well as repeatability of body mass, in young brown trout (Salmo trutta L.) fed a moderately restricted diet (0.5-0.7% fish mass day⁻¹). Metabolism was estimated from measurements of oxygen consumption rate (M(.)(O₂)) and repeatability was evaluated four times across a 15-week period. Individual body mass was highly repeatable across the entire 15 week experimental period whereas residual body-mass-corrected SMR, AMR and AAS showed a gradual loss of repeatability over time. Individual residual SMR, AMR and AAS were significantly repeatable in the short term (5 weeks), gradually declined across the medium term (10 weeks) and completely disappeared in the long term (15 weeks). We suggest that this gradual decline in repeatability was due to the slightly restricted feeding regime. This is discussed in the context of phenotypic plasticity, natural selection and ecology.

  3. Bias and accuracy of resting metabolic rate equations in non-obese and obese adults.

    Science.gov (United States)

    Frankenfield, David C

    2013-12-01

    Consensus on the best equation for predicting metabolic rate in healthy people remains elusive. New equations continue to appear. The purpose of the current study was to validate several standard and new metabolic rate equations in obese and non-obese adults. Resting metabolic rate was measured with indirect calorimetry and calculated using the Mifflin St. Jeor, Livingston, Harris Benedict, Muller, Vander Weg, WHO equations, and the Oxford variation of WHO. Each equation was compared for accuracy (percent of estimates falling within 10% of measured) and bias (95% confidence intervals of differences between estimate and measured expenditure that excluded zero). Three hundred thirty-seven ambulatory, community-living adults were measured. The Mifflin St. Jeor equation was unbiased (95% confidence interval -26 to +8 kcal/day), the Livingston equation tended to underestimate true metabolic rate (95% confidence interval -63 to -25 kcal/day), while all other equations tended to overestimate true metabolic rate. Accuracy rate was similar between Mifflin St. Jeor and Livingston (82 vs. 79%). Accuracy rate was lower in obese than non-obese volunteers, no matter which equation was used (for example 87 vs. 75% for the Mifflin St. Jeor equation). The Mifflin St. Jeor equation is confirmed as a useful prediction equation for resting metabolic rate in community-living ambulatory adults of various body sizes, though the Livingston equation is similar. Accuracy rate is lower in obese than non-obese people, and so an obesity-specific equation is proposed. This equation needs validation before it is adopted for clinical use. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  4. Flight Modes in Migrating European Bee-Eaters: Heart Rate May Indicate Low Metabolic Rate during Soaring and Gliding

    National Research Council Canada - National Science Library

    Sapir, Nir; Wikelski, Martin; McCue, Marshall D; Pinshow, Berry; Nathan, Ran

    2010-01-01

    Many avian species soar and glide over land. Evidence from large birds (mb>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate...

  5. Preferred Barefoot Step Frequency is Influenced by Factors Beyond Minimizing Metabolic Rate

    Science.gov (United States)

    Yandell, Matthew B.; Zelik, Karl E.

    2016-01-01

    Humans tend to increase their step frequency in barefoot walking, as compared to shod walking at the same speed. Based on prior studies and the energy minimization hypothesis we predicted that people make this adjustment to minimize metabolic cost. We performed an experiment quantifying barefoot walking metabolic rate at different step frequencies, specifically comparing preferred barefoot to preferred shod step frequency. We found that subjects increased their preferred frequency when walking barefoot at 1.4 m/s (~123 vs. ~117 steps/min shod, P = 2e-5). However, average barefoot walking metabolic rates at the preferred barefoot and shod step frequencies were not significantly different (P = 0.40). Instead, we observed subject-specific trends: five subjects consistently reduced (−8% average), and three subjects consistently increased (+10% average) their metabolic rate at preferred barefoot vs. preferred shod frequency. Thus, it does not appear that people ubiquitously select a barefoot step frequency that minimizes metabolic rate. We concluded that preferred barefoot step frequency is influenced by factors beyond minimizing metabolic rate, such as shoe properties and/or perceived comfort. Our results highlight the subject-specific nature of locomotor adaptations and how averaging data across subjects may obscure meaningful trends. Alternative experimental designs may be needed to better understand individual adaptations. PMID:26988124

  6. Preferred Barefoot Step Frequency is Influenced by Factors Beyond Minimizing Metabolic Rate

    Science.gov (United States)

    Yandell, Matthew B.; Zelik, Karl E.

    2016-03-01

    Humans tend to increase their step frequency in barefoot walking, as compared to shod walking at the same speed. Based on prior studies and the energy minimization hypothesis we predicted that people make this adjustment to minimize metabolic cost. We performed an experiment quantifying barefoot walking metabolic rate at different step frequencies, specifically comparing preferred barefoot to preferred shod step frequency. We found that subjects increased their preferred frequency when walking barefoot at 1.4 m/s (~123 vs. ~117 steps/min shod, P = 2e-5). However, average barefoot walking metabolic rates at the preferred barefoot and shod step frequencies were not significantly different (P = 0.40). Instead, we observed subject-specific trends: five subjects consistently reduced (-8% average), and three subjects consistently increased (+10% average) their metabolic rate at preferred barefoot vs. preferred shod frequency. Thus, it does not appear that people ubiquitously select a barefoot step frequency that minimizes metabolic rate. We concluded that preferred barefoot step frequency is influenced by factors beyond minimizing metabolic rate, such as shoe properties and/or perceived comfort. Our results highlight the subject-specific nature of locomotor adaptations and how averaging data across subjects may obscure meaningful trends. Alternative experimental designs may be needed to better understand individual adaptations.

  7. Metabolic engineering of Escherichia coli: a sustainable industrial platform for bio-based chemical production.

    Science.gov (United States)

    Chen, Xianzhong; Zhou, Li; Tian, Kangming; Kumar, Ashwani; Singh, Suren; Prior, Bernard A; Wang, Zhengxiang

    2013-12-01

    In order to decrease carbon emissions and negative environmental impacts of various pollutants, more bulk and/or fine chemicals are produced by bioprocesses, replacing the traditional energy and fossil based intensive route. The Gram-negative rod-shaped bacterium, Escherichia coli has been studied extensively on a fundamental and applied level and has become a predominant host microorganism for industrial applications. Furthermore, metabolic engineering of E. coli for the enhanced biochemical production has been significantly promoted by the integrated use of recent developments in systems biology, synthetic biology and evolutionary engineering. In this review, we focus on recent efforts devoted to the use of genetically engineered E. coli as a sustainable platform for the production of industrially important biochemicals such as biofuels, organic acids, amino acids, sugar alcohols and biopolymers. In addition, representative secondary metabolites produced by E. coli will be systematically discussed and the successful strategies for strain improvements will be highlighted. Moreover, this review presents guidelines for future developments in the bio-based chemical production using E. coli as an industrial platform. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds

    Science.gov (United States)

    Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.

    2014-01-01

    In general, tropical birds have a “slow pace of life,” lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal’s life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080

  9. Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

    Directory of Open Access Journals (Sweden)

    Ana Gabriela Jimenez

    Full Text Available In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR, proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR], using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

  10. Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B

    2014-01-01

    In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

  11. Sudden Stops, the Real Exchange Rate and Fiscal Sustainability: Argentina's Lessons

    OpenAIRE

    Izquierdo, Alejandro; Talvi, Ernesto; Calvo, Guillermo A.

    2002-01-01

    This paper offers an alternative explanation for t he fall of Argentina's Convertibility Program based on the country's vulnerability to Sudden Stops in capital flows. Sudden Stops are typically accompanied by a substantial increase in the real exchange rate that wreaks havoc in countries that are heavily dollarized in their liabilities, turning otherwise sustainable fiscal and corporate sector positions into unsustainable ones. In particular, we stress that the required change in relative pr...

  12. Is zero central line-associated bloodstream infection rate sustainable? A 5-year perspective.

    Science.gov (United States)

    Erdei, Carmina; McAvoy, Linda L; Gupta, Munish; Pereira, Sunita; McGowan, Elisabeth C

    2015-06-01

    Adoption and implementation of evidence-based measures for catheter care leads to reductions in central line-associated bloodstream infection (CLABSI) rates in the NICU. The purpose of this study is to evaluate whether this rate reduction is sustainable for at least 1 year and to identify key determinants of this sustainability at the NICU of the Floating Hospital for Children at Tufts Medical Center. We reviewed the incidence of CLABSIs in the NICU temporally to the implementation of new practice policies and procedures, from July 2008 to December 2013. Adoption of standardized care practices, including bundles and checklists, was associated with a significant reduction of the CLABSI rate to zero for >370 consecutive days in our NICU in 2012. Overall, our CLABSI rates decreased from 4.1 per 1000 line days in 2009 (13 infections; 3163 line days) to 0.94 in 2013 (2 infections; 2115 line days), which represents a 77% reduction over a 5-year period. In the first quarter of 2013, there was a brief increase in CLABSI rate to 3.3 per 1000 line days; after a series of interventions, the CLABSI rate was maintained at zero for >600 days. Ongoing training, surveillance, and vigilance with catheter insertion and maintenance practices and improved documentation were identified as key drivers for success. High-quality training, strict compliance with evidence-based guidelines, and thorough documentation is associated with significant reductions in CLABSIs. Mindful organizing may lead to a better understanding of what goes into a unit's ability to handle peak demands and sustain extraordinary performance in the long-term. Copyright © 2015 by the American Academy of Pediatrics.

  13. Sustainable Agro-Food Industrial Wastewater Treatment Using High Rate Anaerobic Process

    Directory of Open Access Journals (Sweden)

    Yung-Tse Hung

    2013-03-01

    Full Text Available This review article compiles the various advances made since 2008 in sustainable high-rate anaerobic technologies with emphasis on their performance enhancement when treating agro-food industrial wastewater. The review explores the generation and characteristics of different agro-food industrial wastewaters; the need for and the performance of high rate anaerobic reactors, such as an upflow anaerobic fixed bed reactor, an upflow anaerobic sludge blanket (UASB reactor, hybrid systems etc.; operational challenges, mass transfer considerations, energy production estimation, toxicity, modeling, technology assessment and recommendations for successful operation

  14. Measurement of flying and diving metabolic rate in wild animals: Review and recommendations.

    Science.gov (United States)

    Elliott, Kyle H

    2016-12-01

    Animals' abilities to fly long distances and dive to profound depths fascinate earthbound researchers. Due to the difficulty of making direct measurements during flying and diving, many researchers resort to modeling so as to estimate metabolic rate during each of those activities in the wild, but those models can be inaccurate. Fortunately, the miniaturization, customization and commercialization of biologgers has allowed researchers to increasingly follow animals on their journeys, unravel some of their mysteries and test the accuracy of biomechanical models. I provide a review of the measurement of flying and diving metabolic rate in the wild, paying particular attention to mass loss, doubly-labelled water, heart rate and accelerometry. Biologgers can impact animal behavior and influence the very measurements they are designed to make, and I provide seven guidelines for the ethical use of biologgers. If biologgers are properly applied, quantification of metabolic rate across a range of species could produce robust allometric relationships that could then be generally applied. As measuring flying and diving metabolic rate in captivity is difficult, and often not directly translatable to field conditions, I suggest that applying multiple techniques in the field to reinforce one another may be a viable alternative. The coupling of multi-sensor biologgers with biomechanical modeling promises to improve precision in the measurement of flying and diving metabolic rate in wild animals. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Albuminuria and Glomerular Filtration Rate in Individuals with Type 1 Diabetes Mellitus: Contribution of Metabolic Syndrome.

    Science.gov (United States)

    Uribe-Wiechers, Ana Cecilia; Janka-Zires, Marcela; Almeda-Valdés, Paloma; López-Gutiérrez, Joel; Gómez-Pérez, Francisco J

    2015-01-01

    The development of metabolic syndrome has been described in patients with type 1 diabetes mellitus as the disease progresses over time. The purpose of this study is to assess the relationship between metabolic syndrome, albuminuria, and glomerular filtration rate, as well as to determine the prevalence of metabolic syndrome, in a group of Mexican patients with type 1 diabetes mellitus. We conducted a cross-sectional study that included patients with type 1 diabetes mellitus who were diagnosed over 10 years ago and who are seen at the Diabetes Intensive Control Clinic of the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran in Mexico City. The presence of metabolic syndrome was determined by using the National Cholesterol Education Program-Adult Treatment Panel III (ATP III) criteria. A total of 81 individuals were studied. The prevalence of metabolic syndrome was 18.5% (n = 15). A higher albuminuria was found in subjects with metabolic syndrome (34.9 mg/24 hours; 8.3-169.3) than in those without metabolic syndrome (9.0 mg/24 hours; 5.0-27.0; p = 0.02). Glomerular filtration rate was lower in patients with metabolic syndrome (95.3 ml/minute; [64.9-107.2] vs. 110.2 ml/minute [88.1-120.3]; p = 0.04). After classifying the population according to the number of metabolic syndrome criteria, a progressive increase in albuminuria and a progressive decrease in glomerular filtration rate were found with each additional metabolic syndrome criterion (p = 0.008 and p = 0.032, respectively). After adjusting for age, time from diagnosis, systolic blood pressure, triglycerides, HDL-cholesterol, and treatment with angiotensin receptor blockers or angiotensin converting enzyme inhibitors, we found that age, time from diagnosis, triglycerides, and HDL-cholesterol were independent factors associated with glomerular filtration rate (R2 = 0.286; p < 0.001). Metabolic syndrome was associated with a higher albuminuria and a reduction in glomerular filtration rate in

  16. Sustainability assessment, rating systems and historical buildings Case study: Rehabilitated construction in a university site

    Directory of Open Access Journals (Sweden)

    Sadrykia Somayeh

    2016-01-01

    Full Text Available This paper explores the relationship between the indicators and different factors that “rating systems for green projects” concentrates on, and principles and factors considered in the rehabilitation of historical buildings. In recent years, different methods and systems concerned and improved for assessing environmental sustainability. LEED (Leadership in Energy and Environmental Design and BREEAM (Building Research Establishment (BRE Environmental Assessment Method are two most commonly used rating systems, established in U.S and UK. These systems comprise some categories and different factors to achieve environmentally responsible design. Firstly, this study focuses on the list of rating systems indicators and criteria. Secondly this paper investigates a historical rehabilitated building in the site of Tabriz Art University, as a case study and has tried to compile its green design elements. Finally, this work intends to compare mentioned elements with indicators and factors of building rating systems. Findings of the study revealed that “Materials and Resources”, “indoor environmental quality” and also “Sustainable Sites” ,the most significant indicator of rating systems, had major and important role in the rehabilitation of the building. Beyond this materials’ life cycle was considerable in construction.

  17. Effects of starvation and molting on the metabolic rate of the bed bug (Cimex lectularius L.).

    Science.gov (United States)

    DeVries, Zachary C; Kells, Stephen A; Appel, Arthur G

    2015-01-01

    The bed bug (Cimex lectularius L.) is a common hematophagous pest in the urban environment and is capable of surviving extended periods of starvation. However, the relationship between starvation and metabolism in bed bugs is not well understood. To better understand this relationship, we measured the metabolism of all life stages for >900 h after feeding (starvation) using closed-system respirometry. Measurements were made around molting for the immature life stages, which occurs only after a blood meal. In addition, both mated and unmated adults were measured. Starvation and molting had significant effects on the metabolism of the bed bug. Mass-specific metabolic rate (V(O2); mL g(-1) h(-1)) declined in a curvilinear fashion with the period of starvation for adults and with the postmolting period for immature bed bugs (used to standardize all immature life stages). A standard curve was developed to depict the generalized pattern of metabolic decline observed in all life stages that molted. Individual metabolic comparisons among life stages that molted revealed some differences in metabolic rate between unmated males and females. In addition, the mass scaling coefficient was found to decline with starvation time (postmolting time) for all life stages that molted. In most life stages, the ratio of V(CO2) to V(O2) (respiratory exchange ratio) declined over time, indicating a change in metabolic substrate with starvation. Finally, daily percent loss in body mass declined in a pattern similar to that of V(O2). The observed patterns in metabolic decline are evaluated in relation to the life history of bed bugs. In addition, the evolutionary development of these patterns is discussed. The metabolic pattern after feeding was also found to share several similarities with that of other ectothermic species.

  18. Variation in energy intake and basal metabolic rate of a bird migrating in a wind tunnel

    NARCIS (Netherlands)

    Lindström, Å.; Klaassen, M.R.J.; Kvist, A.

    1999-01-01

    1. We studied the changes in body mass, metabolizable energy intake rate (ME) and basal metabolic rate (BMR) of a Thrush Nightingale, Luscinia luscinia, following repeated 12-h migratory flights in a wind tunnel. In total the bird flew for 176 h corresponding to 6300 km. This is the first study

  19. Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments

    DEFF Research Database (Denmark)

    Knoblauch, C.; Jørgensen, BB; Harder, J.

    1999-01-01

    of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than...

  20. Interplay between metabolic rate and diet quality in the South American fox, Pseudalopex culpaeus.

    Science.gov (United States)

    Silva, Sergio I; Jaksic, Fabian M; Bozinovic, Francisco

    2004-01-01

    We studied the metabolic costs associated with the ingestion of peppertree fruits (Schinus molle) in the culpeo fox, Pseudalopex culpaeus, the second largest canid in South America. Throughout its range of distribution, this fox feeds on rodents and other small vertebrates, and also on peppertree fruits, which represent 98% of total fruits consumed in semiarid Chile. Peppertree contains a high diversity of phytochemicals. Foxes feeding on diets containing rats and peppertree fruits (mixed diets) exhibited a 98.9% increase in basal rate of metabolism when compared to rat-acclimated foxes. Thus, acute ingestion of chemically defended fruits has an energetic cost for the fox, reflected in higher values of basal metabolism. Increased metabolic rates may be associated with increased protein synthesis for detoxification and for tissue repair, including the production of biotransformation enzymes.

  1. Physical activity, heart rate, metabolic profile, and estradiol in premenopausal women

    DEFF Research Database (Denmark)

    Emaus, Aina; Veierød, Marit B; Furberg, Anne-Sofie

    2008-01-01

    PURPOSE: To study whether physical inactive women with a tendency to develop metabolic syndrome have high levels of 17beta-estradiol (E2) of importance for breast cancer risk. METHODS: Two hundred and four healthy women of reproductive age were assessed for self-reported leisure-time physical...... activity (LPA), resting heart rate (HR), blood pressure (BP), anthropometry, and serum glucose, lipids, and insulin [Norwegian Energy Balance and Breast Cancer Aspect (EBBA) study]. E2 was measured in daily saliva samples throughout an entire menstrual cycle. A clustered metabolic risk score [z metabolic...

  2. Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods

    Directory of Open Access Journals (Sweden)

    Romain Dubois, Thierry Paillard, Mark Lyons, David McGrath, Olivier Maurelli, Jacques Prioux

    2017-03-01

    Full Text Available The aims of this study were (1 to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2 to explore the relationship between these methods and (3 to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y, over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; p<0.01 while the forwards cover more distance than the backs (+26.8 ± 5.7%; p<0.05 in moderate-speed zone (10-14.4 km·h-1. However, no significant difference in high-metabolic power distance was found between the backs and forwards. Indeed, the high-metabolic power distances were greater than high-speed running distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; p<0.001 between the two groups. Nevertheless, nearly perfect correlations were found between the total distance assessed using the traditional approach and the metabolic power approach (r = 0.98. Furthermore, there is a strong association (r = 0.93 between the high-speed running distance (assessed using the traditional approach and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high

  3. Sustained zero-order delivery of GC-1 from a nanochannel membrane device alleviates metabolic syndrome.

    Science.gov (United States)

    Filgueira, C S; Nicolov, E; Hood, R L; Ballerini, A; Garcia-Huidobro, J; Lin, J Z; Fraga, D; Webb, P; Sabek, O M; Gaber, A O; Phillips, K J; Grattoni, A

    2016-11-01

    Our objective was to assess the sustained, low-dose and constant administration of the thyroid receptor-β (TRβ)-selective agonist GC-1 (sobetirome) from a novel nanochannel membrane device (NMD) for drug delivery. As it known to speed up metabolism, accomplish weight loss, improve cholesterol levels and possess anti-diabetic effects, GC-1 was steadily administered by our NMD, consisting of an implantable nanochannel membrane, as an alternative to conventional daily administration, which is subject to compliance issues in clinical settings. Diet-induced obese C57BL/J6 male mice were fed a very high-fat diet (VHFD) and received NMD implants subcutaneously. Ten mice per group received capsules containing GC-1 or phosphate-buffered saline (control). Weight, lean and fat mass, as well as cholesterol, triglycerides, insulin and glucose, were monitored for 24 days. After treatment, plasma levels of thyroid-stimulating hormone (TSH) and thyroxine were compared. mRNA levels of a panel of thermogenic markers were examined using real-time PCR in white adipose tissue (WAT) and brown adipose tissue (BAT). Adipose tissue, liver and local inflammatory response to the implant were examined histologically. Pancreatic islet number and β-cell area were assessed. GC-1 released from the NMD reversed VHFD-induced obesity and normalized serum cholesterol and glycemia. Significant reductions in body weight and fat mass were observed within 10 days, whereas reductions in serum cholesterol and glucose levels were seen within 7 days. The significant decrease in TSH was consistent with TRβ selectivity for GC-1. Levels of transcript for Ucp1 and thermogenic genes PGC1a, Cidea, Dio2 and Cox5a showed significant upregulation in WAT in NMD-GC-1-treated mice, but decreased in BAT. Although mice treated by NMD-GC-1 showed a similar number of pancreatic islets, they exhibited significant increase in β-cell area. Our data demonstrate that the NMD implant achieves steady administration of GC-1

  4. Genetic relation of life span to metabolic rate for inbred mouse strains and their hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, G.A.; Duffy, P.H.

    1979-02-01

    Average life spans were estimated for the male progeny from 21 of the 25 possible matings of 5 inbred mouse strains. Oxygen consumption was measured in an open system over a 48-hour interval. Resting metabolism, M/sub re/, and average metabolism, M/sub av/, were determined at 6 to 8 months of age, and at 24 to 34 months. Body weight, W, was determined at the time metabolism was measured. Life span, L, is negatively correlated with M/sub re/, and M/sub av/, and positively correlated with W at both ages of measurement. This is in accord with the metabolic wear factor that had previously been established among 85 different species of mammals. A new metabolism variable, the energy partition coefficient, defined as the ratio of average to resting metabolic rate, M/sub av//M/sub re/, has a parabolic relation to body weight, i.e., is maximal at an intermediate body size. The squared body weight deviation in turn has a negative correlation with life span. The correlation of L with M/sub av//M/sub re/ is positive, as expected, but not significant. These data suggest the existence of a longevity factor dependent on the partition of energy between the phasic metabolism of activity and the continuous maintenance metabolism.

  5. Effect of the helicity injection rate and the Lundquist number on spheromak sustainment

    Energy Technology Data Exchange (ETDEWEB)

    García-Martínez, Pablo Luis, E-mail: pablogm@cab.cnea.gov.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Sede Andina—Universidad Nacional de Río Negro (UNRN), Av. Bustillo 9500, 8400 San Carlos de Bariloche, Río Negro (Argentina); Lampugnani, Leandro Gabriel; Farengo, Ricardo [Instituto Balseiro and Centro Atómico Bariloche (CAB-CNEA), Av. Bustillo 9500, 8400 San Carlos de Bariloche, Río Negro (Argentina)

    2014-12-15

    The dynamics of the magnetic relaxation process during the sustainment of spheromak configurations at different helicity injection rates is studied. The three-dimensional activity is recovered using time-dependent resistive magnetohydrodynamic simulations. A cylindrical flux conserver with concentric electrodes is used to model configurations driven by a magnetized coaxial gun. Magnetic helicity is injected by tangential boundary flows. Different regimes of sustainment are identified and characterized in terms of the safety factor profile. The spatial and temporal behavior of fluctuations is described. The dynamo action is shown to be in close agreement with existing experimental data. These results are relevant to the design and operation of helicity injected devices, as well as to basic understanding of the plasma relaxation mechanism in quasi-steady state.

  6. Effect of the helicity injection rate and the Lundquist number on spheromak sustainment

    Science.gov (United States)

    García-Martínez, Pablo Luis; Lampugnani, Leandro Gabriel; Farengo, Ricardo

    2014-12-01

    The dynamics of the magnetic relaxation process during the sustainment of spheromak configurations at different helicity injection rates is studied. The three-dimensional activity is recovered using time-dependent resistive magnetohydrodynamic simulations. A cylindrical flux conserver with concentric electrodes is used to model configurations driven by a magnetized coaxial gun. Magnetic helicity is injected by tangential boundary flows. Different regimes of sustainment are identified and characterized in terms of the safety factor profile. The spatial and temporal behavior of fluctuations is described. The dynamo action is shown to be in close agreement with existing experimental data. These results are relevant to the design and operation of helicity injected devices, as well as to basic understanding of the plasma relaxation mechanism in quasi-steady state.

  7. Temporal repeatability of metabolic rate and the effect of organ mass and enzyme activity on metabolism in European eel (Anguilla anguilla).

    Science.gov (United States)

    Boldsen, Martin Maagaard; Norin, Tommy; Malte, Hans

    2013-05-01

    Intraspecific variation in metabolic rate of fish can be pronounced and have been linked to various fitness-related behavioural and physiological traits, but the underlying causes for this variation have received far less attention than the consequences of it. In the present study we investigated whether European eels (Anguilla anguilla) displayed temporal repeatability of body-mass-corrected (residual) metabolic rate over a two-month period and if variations in organ mass and enzyme activity between individual fish could be the cause for the observed variation in metabolic rate. Both standard metabolic rate (SMR; Pearson's r=0.743) and routine metabolic rate (RMR; r=0.496) were repeatable over the two-month period. Repeatability of RMR is an interesting finding as it indicates that the level of spontaneous activity in respirometer-confined fish is not random. Cumulative organ mass (liver, heart, spleen and intestine; mean 1.6% total body mass) was found to explain 38% of the variation in SMR (r=0.613) with the liver (one of the metabolically most active organs) being the driver for the correlation between organ mass and metabolic rate. No relationships were found for either liver citrate synthase or cytochrome oxidase activity and metabolic rate in the European eels. Reasons for, and contributions to, the observed variation in metabolic rate are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia.

    Science.gov (United States)

    Clark, Steven L; Hamilton, Emily F; Garite, Thomas J; Timmins, Audra; Warrick, Philip A; Smith, Samuel

    2017-02-01

    Despite intensive efforts directed at initial training in fetal heart rate interpretation, continuing medical education, board certification/recertification, team training, and the development of specific protocols for the management of abnormal fetal heart rate patterns, the goals of consistently preventing hypoxia-induced fetal metabolic acidemia and neurologic injury remain elusive. The purpose of this study was to validate a recently published algorithm for the management of category II fetal heart rate tracings, to examine reasons for the birth of infants with significant metabolic acidemia despite the use of electronic fetal heart rate monitoring, and to examine critically the limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia. The potential performance of electronic fetal heart rate monitoring under ideal circumstances was evaluated in an outcomes-blinded examination fetal heart rate tracing of infants with metabolic acidemia at birth (base deficit, >12) and matched control infants (base deficit, fetal heart rate tracings, followed by delivery within 30 minutes, (4) evaluation without the need to provide patient care simultaneously, and (5) comparison of results under these circumstances with those achieved in actual clinical practice. During the study period, 120 infants were identified with an arterial cord blood base deficit of >12 mM/L. Matched control infants were not demographically different from subjects. In actual practice, operative intervention on the basis of an abnormal fetal heart rate tracings occurred in 36 of 120 fetuses (30.0%) with metabolic acidemia. Based on expert, algorithm-assisted reviews, 55 of 120 patients with acidemia (45.8%) were judged to need operative intervention for abnormal fetal heart rate tracings. This difference was significant (P=.016). In infants who were born with a base deficit of >12 mM/L in which blinded, algorithm-assisted expert review indicated the need for

  9. Muscle vibration sustains motor unit firing rate during submaximal isometric fatigue in humans.

    Science.gov (United States)

    Griffin, L; Garland, S J; Ivanova, T; Gossen, E R

    2001-09-15

    1. In keeping with the 'muscular wisdom hypothesis', many studies have documented that the firing rate of the majority of motor units decreased during fatiguing isometric contractions. The present study investigated whether the application of periodic muscle vibration, which strongly activates muscle spindles, would alter the modulation of motor unit firing rate during submaximal fatiguing isometric contractions. 2. Thirty-three motor units from the lateral head of the triceps brachii muscle were recorded from 10 subjects during a sustained isometric 20 % maximal voluntary contraction (MVC) of the elbow extensors. Vibration was interposed on the contraction for 2 s every 10 s. Twenty-two motor units were recorded from the beginning of the fatigue task. The discharge rate of the majority of motor units remained constant (12/22) or increased (4/22) with fatigue. Six motor units demonstrated a reduction in discharge rate that later returned toward initial values; these motor units had higher initial discharge rates than the other 16 motor units. 3. In a second series of experiments, four subjects held a sustained isometric 20 % MVC for 2 min and then vibration was applied as above for the remainder of the contraction. In this case, motor units initially demonstrated a decrease in firing rate that increased after the vibration was applied. Thus muscle spindle disfacilitation of the motoneurone pool may be associated with the decline of motor unit discharge rate observed during the first 2 min of the contraction. 4. In a third set of experiments, seven subjects performed the main experiment on one occasion and repeated the fatigue task without vibration on a second occasion. Neither the endurance time of the fatiguing contraction nor the MVC torque following fatigue was affected by the application of vibration. This finding calls into question the applicability of the muscular wisdom hypothesis to submaximal contractions.

  10. Effect of photoperiod on longevity and metabolic rate in Anopheles quadrimaculatus.

    Science.gov (United States)

    Lanciani, C A; Anderson, J F

    1993-06-01

    The effect of photoperiod on longevity of nondiapausing members of a species in the mosquito species complex Anopheles quadrimaculatus was tested in laboratory experiments. First-generation adults reared from 2 field collections showed the same trends: those reared under short photoperiod (8 h light: 16 h dark) lived longer than did those reared under long photoperiod (16 h light: 8 h dark). Adult metabolic rates were not consistently related to longevity. In adults reared from the first collection, metabolic rates were higher in long-photoperiod individuals but in adults reared from the second collection, metabolic rates were higher in short-photoperiod individuals. Longevity appears to be another of many insect features that are affected similarly by temperature and photoperiod.

  11. Negative relationships between population density and metabolic rates are not general.

    Science.gov (United States)

    Yashchenko, Varvara; Fossen, Erlend Ignacio; Kielland, Øystein Nordeide; Einum, Sigurd

    2016-07-01

    Population density has recently been suggested to be an important factor influencing metabolic rates and to represent an important 'third axis' explaining variation beyond that explained by body mass and temperature. In situations where population density influences food consumption, the immediate effect on metabolism acting through specific dynamic action (SDA), and downregulation due to fasting over longer periods, is well understood. However, according to a recent review, previous studies suggest a more general effect of population density per se, even in the absence of such effects. It has been hypothesized that this results from animals performing anticipatory responses (i.e. reduced activity) to expected declines in food availability. Here, we test the generality of this finding by measuring density effects on metabolic rates in 10 clones from two different species of the zooplankton Daphnia (Daphnia pulex Leydig and D. magna Straus). Using fluorescence-based respirometry, we obtain high-precision measures of metabolism. We also identify additional studies on this topic that were not included in the previous review, compare the results and evaluate the potential for measurement bias in all previous studies. We demonstrate significant variation in mass-specific metabolism among clones within both species. However, we find no evidence for a negative relationship between population density and mass-specific metabolism. The previously reported pattern also disappeared when we extended the set of studies analysed. We discuss potential reasons for the discrepancy among studies, including two main sources of potential bias (microbial respiration and declining oxygen consumption due to reduced oxygen availability). Only one of the previous studies gives sufficient information to conclude the absence of such biases, and consistent with our results, no effect of density on metabolism was found. We conclude that population density per se does not have a general effect

  12. Effect and Analysis of Sustainable Cell Rate using MPEG video Traffic in ATM Networks

    Directory of Open Access Journals (Sweden)

    Sakshi Kaushal

    2006-04-01

    Full Text Available The broadband networks inhibit the capability to carry multiple types of traffic – voice, video and data, but these services need to be controlled according to the traffic contract negotiated at the time of the connection to maintain desired Quality of service. Such control techniques use traffic descriptors to evaluate its performance and effectiveness. In case of Variable Bit Rate (VBR services, Peak Cell Rate (PCR and its Cell Delay Variation Tolerance (CDVTPCR are mandatory descriptors. In addition to these, ATM Forum proposed Sustainable Cell Rate (SCR and its Cell delay variation tolerance (CDVTSCR. In this paper, we evaluated the impact of specific SCR and CDVTSCR values on the Usage Parameter Control (UPC performance in case of measured MPEG traffic for improving the efficiency

  13. Characteristics of Resting Metabolic Rate in Critically Ill, Mechanically Ventilated Adults With Cystic Fibrosis.

    Science.gov (United States)

    Frankenfield, David C; Ashcraft, Christine M; Drasher, Tammy L; Reid, Elizabeth K; Vender, Robert L

    2017-05-01

    Critically ill patients with cystic fibrosis may be especially sensitive to the negative consequences of overfeeding and underfeeding, yet there is almost no information available about the energy needs of these patients. The purpose of this study was to characterize the metabolic rate of critically ill adult patients with cystic fibrosis requiring mechanical ventilation. This was an observational study in which the resting metabolic rate, oxygen consumption, and carbon dioxide production of adult patients with cystic fibrosis requiring critical care, sedation, and mechanical ventilation were measured with indirect calorimetry. This group was compared with a cohort of adult critical care patients without cystic fibrosis. Twelve patients with cystic fibrosis were identified and measured. These were compared with a control group of 25 critically ill patients. Both groups were underweight (body mass index, 17.4 ± 4.0 kg/m2 in cystic fibrosis and 18.4 ± 2.3 kg/m2 in control). Adjusting for differences in age, sex, height, and weight, there was no difference in resting metabolic rate between the cystic fibrosis and control groups (1702 ± 193 vs 1642 ± 194 kcal/d, P = .388). Measured resting metabolic rate matched predicted values 58% of the time in cystic fibrosis and 60% of the time in control. The resting metabolic rate of sedated adult patients with cystic fibrosis being assisted with mechanical ventilation is not different from that of adult critical care patients without cystic fibrosis. In both these underweight groups, accurate prediction of resting metabolic rate is difficult to obtain.

  14. The relationship of sleep with temperature and metabolic rate in a hibernating primate.

    Directory of Open Access Journals (Sweden)

    Andrew D Krystal

    Full Text Available STUDY OBJECTIVES: It has long been suspected that sleep is important for regulating body temperature and metabolic-rate. Hibernation, a state of acute hypothermia and reduced metabolic-rate, offers a promising system for investigating those relationships. Prior studies in hibernating ground squirrels report that, although sleep occurs during hibernation, it manifests only as non-REM sleep, and only at relatively high temperatures. In our study, we report data on sleep during hibernation in a lemuriform primate, Cheirogaleus medius. As the only primate known to experience prolonged periods of hibernation and as an inhabitant of more temperate climates than ground squirrels, this animal serves as an alternative model for exploring sleep temperature/metabolism relationships that may be uniquely relevant to understanding human physiology. MEASUREMENTS AND RESULTS: We find that during hibernation, non-REM sleep is absent in Cheirogaleus. Rather, periods of REM sleep occur during periods of relatively high ambient temperature, a pattern opposite of that observed in ground squirrels. Like ground squirrels, however, EEG is marked by ultra-low voltage activity at relatively low metabolic-rates. CONCLUSIONS: These findings confirm a sleep-temperature/metabolism link, though they also suggest that the relationship of sleep stage with temperature/metabolism is flexible and may differ across species or mammalian orders. The absence of non-REM sleep suggests that during hibernation in Cheirogaleus, like in the ground squirrel, the otherwise universal non-REM sleep homeostatic response is greatly curtailed or absent. Lastly, ultra-low voltage EEG appears to be a cross-species marker for extremely low metabolic-rate, and, as such, may be an attractive target for research on hibernation induction.

  15. Equilibrium exchange rate assessment in Serbia using the IMF external sustainability approach

    Directory of Open Access Journals (Sweden)

    Pažun Brankica

    2014-01-01

    Full Text Available The exchange rate has always been a topical issue, particularly in the last two decades, at the time of strong world economy globalisation, as well as liberalization of international flows of goods, services and factors of production, which has resulted in stronger trade and financial integration. There has been a rise in the share of trade in world GDP. Growing developing countries contribute significantly to this growth, which is evident from the data that show increase of their share in world trade , as well as their importance in international capital flows. One of the most important concepts in open macroeconomics is the equilibrium real exchange rate - ERER. Deviations of the real exchange rate are considered to be the cause of the loss of competitiveness and economic slowdown, as well as possible currency crisis (overvaluation and undervaluation. Disadvantages of traditional concepts in exchange rate assessment which are very often reflected in unsuccessful empirical results, motivate experts to seek alternative models to assist in equilibrium exchange rate analysis. This paper aims to present one of three complementary methodologies used by the International Monetary Fund, for the equilibrium real exchange rate assessment in Serbia, as well as the deviation of the real exchange rate from its (estimated equilibrium, that is external sustainability approach.

  16. Standard metabolic rate is associated with gestation duration, but not clutch size, in speckled cockroaches Nauphoeta cinerea

    OpenAIRE

    Schimpf, Natalie G.; Matthews, Philip G. D.; White, Craig R.

    2012-01-01

    Summary Metabolic rate varies significantly between individuals, and these differences persist even when the wide range of biotic and abiotic factors that influence metabolism are accounted for. It is important to understand the life history implications of variation in metabolic rate, but they remain poorly characterised despite a growing body of work examining relationships between metabolism and a range of traits. In the present study we used laboratory-bred families (one sire to three ...

  17. Quantitative Rates of Brain Glucose Metabolism Distinguish Minimally Conscious from Vegetative State Patients

    DEFF Research Database (Denmark)

    Stender, Johan; Kupers, Ron; Rodell, Anders

    2015-01-01

    of these patients. However, no quantitative comparisons of cerebral glucose metabolism in VS/UWS and MCS have yet been reported. We calculated the regional and whole-brain CMRglc of 41 patients in the states of VS/UWS (n=14), MCS (n=21) or emergence from MCS (EMCS, n=6), and healthy volunteers (n=29). Global...... cortical CMRglc in VS/UWS and MCS averaged 42% and 55% of normal, respectively. Differences between VS/UWS and MCS were most pronounced in the frontoparietal cortex, at 42% and 60% of normal. In brainstem and thalamus, metabolism declined equally in the two conditions. In EMCS, metabolic rates were...... indistinguishable from those of MCS. Ordinal logistic regression predicted that patients are likely to emerge into MCS at CMRglc above 45% of normal. Receiver-operating characteristics showed that patients in MCS and VS/UWS can be differentiated with 82% accuracy, based on cortical metabolism. Together...

  18. Winter Is Coming: Seasonal Variation in Resting Metabolic Rate of the European Badger (Meles meles).

    Science.gov (United States)

    McClune, David W; Kostka, Berit; Delahay, Richard J; Montgomery, W Ian; Marks, Nikki J; Scantlebury, David M

    2015-01-01

    Resting metabolic rate (RMR) is a measure of the minimum energy requirements of an animal at rest, and can give an indication of the costs of somatic maintenance. We measured RMR of free-ranging European badgers (Meles meles) to determine whether differences were related to sex, age and season. Badgers were captured in live-traps and placed individually within a metabolic chamber maintained at 20 ± 1°C. Resting metabolic rate was determined using an open-circuit respirometry system. Season was significantly correlated with RMR, but no effects of age or sex were detected. Summer RMR values were significantly higher than winter values (mass-adjusted mean ± standard error: 2366 ± 70 kJ⋅d(-1); 1845 ± 109 kJ⋅d(-1), respectively), with the percentage difference being 24.7%. While under the influence of anaesthesia, RMR was estimated to be 25.5% lower than the combined average value before administration, and after recovery from anaesthesia. Resting metabolic rate during the autumn and winter was not significantly different to allometric predictions of basal metabolic rate for mustelid species weighing 1 kg or greater, but badgers measured in the summer had values that were higher than predicted. Results suggest that a seasonal reduction in RMR coincides with apparent reductions in physical activity and body temperature as part of the overwintering strategy ('winter lethargy') in badgers. This study contributes to an expanding dataset on the ecophysiology of medium-sized carnivores, and emphasises the importance of considering season when making predictions of metabolic rate.

  19. A comparison of methods for fitting allometric equations to field metabolic rates of animals.

    Science.gov (United States)

    Packard, Gary C; Boardman, Thomas J

    2009-02-01

    We re-examined data for field metabolic rates of varanid lizards and marsupial mammals to illustrate how different procedures for fitting the allometric equation can lead to very different estimates for the allometric coefficient and exponent. A two-parameter power function was obtained in each case by the traditional method of back-transformation from a straight line fitted to logarithms of the data. Another two-parameter power function was then generated for each data-set by non-linear regression on values in the original arithmetic scale. Allometric equations obtained by non-linear regression described the metabolic rates of all animals in the samples. Equations estimated by back-transformation from logarithms, on the other hand, described the metabolic rates of small species but not large ones. Thus, allometric equations estimated in the traditional way for field metabolic rates of varanids and marsupials do not have general importance because they do not characterize rates for species spanning the full range in body size. Logarithmic transformation of predictor and response variables creates new distributions that may enable investigators to perform statistical analyses in compliance with assumptions underlying the tests. However, statistical models fitted to transformations should not be used to estimate parameters of equations in the arithmetic domain because such equations may be seriously biased and misleading. Allometric analyses should be performed on values expressed in the original scale, if possible, because this is the scale of interest.

  20. Swimming metabolic rates vary by sex and development stage, but not by species, in three species of Australian otariid seals.

    Science.gov (United States)

    Ladds, Monique A; Slip, David J; Harcourt, Robert G

    2017-04-01

    Physiology may limit the ability for marine mammals to adapt to changing environments. Depth and duration of foraging dives are a function of total available oxygen stores, which theoretically increase as animals grow, and metabolic costs. To evaluate how physiology may influence the travelling costs for seals to foraging patches in the wild, we measured metabolic rates of a cross-section of New Zealand fur seals, Australian fur seals and Australian sea lions representing different foraging strategies, development stages, sexes and sizes. We report values for standard metabolic rate, active metabolic rate (obtained from submerged swimming), along with estimates of cost of transport (COT), measured via respirometry. We found a decline in mass-specific metabolic rate with increased duration of submerged swimming. For most seals mass-specific metabolic rate increased with speed and for all seals mass-specific COT decreased with speed. Mass-specific metabolic rate was higher for subadult than adult fur seals and sea lions, corresponding to an overall higher minimum COT. Some sex differences were also apparent, such that female Australian fur seals and Australian sea lions had higher mass-specific metabolic rates than males. There were no species differences in standard or active metabolic rates for adult males or females. The seals in our study appear to operate at their physiological optimum during submerged swimming. However, the higher metabolic rates of young and female fur seals and sea lions may limit their scope for increasing foraging effort during times of resource limitation.

  1. Intra-seasonal flexibility in avian metabolic performance highlights the uncoupling of basal metabolic rate and thermogenic capacity.

    Science.gov (United States)

    Petit, Magali; Lewden, Agnès; Vézina, François

    2013-01-01

    Stochastic winter weather events are predicted to increase in occurrence and amplitude at northern latitudes and organisms are expected to cope through phenotypic flexibility. Small avian species wintering in these environments show acclimatization where basal metabolic rate (BMR) and maximal thermogenic capacity (MSUM) are typically elevated. However, little is known on intra-seasonal variation in metabolic performance and on how population trends truly reflect individual flexibility. Here we report intra-seasonal variation in metabolic parameters measured at the population and individual levels in black-capped chickadees (Poecileatricapillus). Results confirmed that population patterns indeed reflect flexibility at the individual level. They showed the expected increase in BMR (6%) and MSUM (34%) in winter relative to summer but also, and most importantly, that these parameters changed differently through time. BMR began its seasonal increase in November, while MSUM had already achieved more than 20% of its inter-seasonal increase by October, and declined to its starting level by March, while MSUM remained high. Although both parameters co-vary on a yearly scale, this mismatch in the timing of variation in winter BMR and MSUM likely reflects different constraints acting on different physiological components and therefore suggests a lack of functional link between these parameters.

  2. Mini-review: high rate algal ponds, flexible systems for sustainable wastewater treatment.

    Science.gov (United States)

    Young, P; Taylor, M; Fallowfield, H J

    2017-06-01

    Over the last 20 years, there has been a growing requirement by governments around the world for organisations to adopt more sustainable practices. Wastewater treatment is no exception, with many currently used systems requiring large capital investment, land area and power consumption. High rate algal ponds offer a sustainable, efficient and lower cost option to the systems currently in use. They are shallow, mixed lagoon based systems, which aim to maximise wastewater treatment by creating optimal conditions for algal growth and oxygen production-the key processes which remove nitrogen and organic waste in HRAP systems. This design means they can treat wastewater to an acceptable quality within a fifth of time of other lagoon systems while using 50% less surface area. This smaller land requirement decreases both the construction costs and evaporative water losses, making larger volumes of treated water available for beneficial reuse. They are ideal for rural, peri-urban and remote communities as they require minimum power and little on-site management. This review will address the history of and current trends in high rate algal pond development and application; a comparison of their performance with other systems when treating various wastewaters; and discuss their potential for production of added-value products. Finally, the review will consider areas requiring further research.

  3. Does metabolic rate and evaporative water loss reflect differences in migratory strategy in sexually dimorphic hoverflies?

    Science.gov (United States)

    Tomlinson, Sean; Menz, Myles H M

    2015-12-01

    A typical explanation for ecologically stable strategies that apply to only a proportion of a population, is bet hedging, where increased reproductive success offsets reduced reproductive rate. One such is partial migration, where only a proportion of a population moves seasonally to avoid inclement climatic conditions. Bet hedging may overlook unseen costs to maintain broad physiological resilience, implied by encountering a breadth of environmental conditions. We investigated the physiological correlates of partial migration by measuring standard metabolic rates, and rates of evaporative water loss, and then estimating upper and lower thermal tolerance in males and females of two hoverfly species, Episyrphus balteatus and Eristalis tenax. In central Europe, females of these species may either migrate or overwinter, whereas males may migrate south to the Mediterranean, but have not been found overwintering. Both species were sexually dimorphic; female Ep. balteatus were lighter than males, but female Er. tenax were heavier than males. While allometrically- corrected metabolic rate in both species increased with temperature, the most parsimonious models included no sex-specific differences in metabolic rate for either species. Evaporative water loss of both species also increased with temperature, but was higher for females of both species than males. Assuming that resting metabolism is congruent with the activity requirements of migration, highly consistent thermal tolerance and metabolic rate suggests that any given fly could migrate, although water loss patterns suggest that females may be less well-adapted to Mediterranean climates. We infer that partial migration probably results from the imperatives of their reproductive strategies. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Heart rate variability and metabolic syndrome in hospitalized patients with schizophrenia.

    Science.gov (United States)

    Lee, Kyunghee; Park, Jeongeon; Choi, Jeongim; Park, Chang Gi

    2011-12-01

    Reduced heart rate variability significantly increases cardiovascular mortality. Metabolic syndrome increases the cardiac autonomic dysfunction. Recently, increasing cardiovascular mortality has been reported in patients with schizophrenia. This study was done to compare heart rate variability between adults with and without schizophrenia and to compare the relationship of heart rate variability to metabolic syndrome in hospitalized patients with schizophrenia. This was a descriptive and correlational study in which 719 adults without schizophrenia and 308 adults with schizophrenia took part between May and June 2008. We measured the following: five-minute heart rate variability; high-frequency, low-frequency, the ratio of low-frequency to high-frequency, and the Standard Deviation of all the normal RR intervals. Data was also collected on metabolic syndrome, abdominal obesity, triglycerides, HDL cholesterol, blood pressure and fasting glucose. The Standard Deviation of all the normal RR intervals values of heart rate variability indices were 1.53±0.18. The low-frequency and high-frequency values of heart rate variability indices were significantly higher in hospitalized patients with schizophrenia (3.89±1.36; 3.80±1.20) than those in the healthy participants (2.20±0.46; 2.10±0.46). There were no significant differences between the schizophrenic patients with and without metabolic syndrome. The results of this study indicate that schizophrenia patients have significantly lower cardiac autonomic control, but they have significantly higher low-frequency and high-frequency values than those of healthy adults. Use of antipsychotic drug may affect the autonomic nervous system in schizophrenic patients. Metabolic syndrome was not associated with cardiac autonomic control in schizophrenia patients.

  5. Sustainable Sites Initiative: US updated rating criteria for open spaces design

    Directory of Open Access Journals (Sweden)

    Renata Valente

    2014-10-01

    Full Text Available The paper presents the U.S. Sustainable Sites Initiative, by illustrating and commenting the recent updates of the rating criteria in addition to a number of certified projects, including some sites visited by the author in California. The system is compared with existing tools, as LEED 2009 for Neighborhood Development Rating System, albeit some differences also in scale of interventions. In the work, scientific literature and personal considerations are given about those aspects still not evaluated by the system and its potential wider applicability with regard to directions of research on the topic. The theme fits well in the mainstream of studies dedicated to the design of resilient open spaces, contributing to adaptation and mitigation of climate change.

  6. Relationship between resting pulse rate and lipid metabolic dysfunctions in Chinese adults living in rural areas.

    Directory of Open Access Journals (Sweden)

    Chong-jian Wang

    Full Text Available BACKGROUND: Resting pulse rate has been observed to be associated with cardiovascular diseases. However, its association with lipid metabolic dysfunctions remains unclear, especially resting pulse rate as an indicator for identifying the risk of lipid metabolic dysfunctions. The purpose of this study was to examine the association between resting pulse rate and lipid metabolic dysfunctions, and then evaluate the feasibility of resting pulse rate as an indicator for screening the risk of lipid metabolic dysfunctions. METHODS: A cross-sectional survey was performed, and 16,926 subjects were included in this study from rural community residents aged 35-78 years. Resting pulse rate and relevant covariates were collected from a standard questionnaire. The fasting blood samples were collected and measured for lipid profile. Predictive performance was analyzed by receiver operating characteristic (ROC curve. RESULTS: A significant correlation was observed between resting pulse rate and TC (r = 0.102, P = 0.001, TG (r = 0.182, P = 0.001, and dyslipidemia (r = 0.037, P = 0.008. In the multivariate models, the adjusted odds ratios for hypercholesterolemia (from 1.07 to 1.15, hypertriglyceridemia (1.11 to 1.16, low HDL hypercholesterolemia (1.03 to 1.06, high LDL hypercholesterolemia (0.92 to 1.14, and dyslipidemia (1.04 to 1.07 were positively increased across quartiles of resting pulse rate (P for trend <0.05. The ROC curve indicated that resting pulse rate had low sensitivity (78.95%, 74.18%, 51.54%, 44.39%, and 54.22%, specificity (55.88%, 59.46%, 57.27%, 65.02%, and 60.56%, and the area under ROC curve (0.70, 0.69, 0.54, 0.56, and 0.58 for identifying the risk of hypercholesterolemia, hypertriglyceridemia, low HDL hypercholesterolemia, high LDL hypercholesterolemia, and dyslipidemia, respectively. CONCLUSION: Fast resting pulse rate was associated with a moderate increased risk of lipid metabolic dysfunctions in rural adults. However, resting pulse

  7. Relationship between resting pulse rate and lipid metabolic dysfunctions in Chinese adults living in rural areas.

    Science.gov (United States)

    Wang, Chong-jian; Li, Yu-qian; Li, Lin-lin; Wang, Ling; Zhao, Jing-zhi; You, Ai-guo; Guo, Yi-rui; Li, Wen-jie

    2012-01-01

    Resting pulse rate has been observed to be associated with cardiovascular diseases. However, its association with lipid metabolic dysfunctions remains unclear, especially resting pulse rate as an indicator for identifying the risk of lipid metabolic dysfunctions. The purpose of this study was to examine the association between resting pulse rate and lipid metabolic dysfunctions, and then evaluate the feasibility of resting pulse rate as an indicator for screening the risk of lipid metabolic dysfunctions. A cross-sectional survey was performed, and 16,926 subjects were included in this study from rural community residents aged 35-78 years. Resting pulse rate and relevant covariates were collected from a standard questionnaire. The fasting blood samples were collected and measured for lipid profile. Predictive performance was analyzed by receiver operating characteristic (ROC) curve. A significant correlation was observed between resting pulse rate and TC (r = 0.102, P = 0.001), TG (r = 0.182, P = 0.001), and dyslipidemia (r = 0.037, P = 0.008). In the multivariate models, the adjusted odds ratios for hypercholesterolemia (from 1.07 to 1.15), hypertriglyceridemia (1.11 to 1.16), low HDL hypercholesterolemia (1.03 to 1.06), high LDL hypercholesterolemia (0.92 to 1.14), and dyslipidemia (1.04 to 1.07) were positively increased across quartiles of resting pulse rate (P for trend rate had low sensitivity (78.95%, 74.18%, 51.54%, 44.39%, and 54.22%), specificity (55.88%, 59.46%, 57.27%, 65.02%, and 60.56%), and the area under ROC curve (0.70, 0.69, 0.54, 0.56, and 0.58) for identifying the risk of hypercholesterolemia, hypertriglyceridemia, low HDL hypercholesterolemia, high LDL hypercholesterolemia, and dyslipidemia, respectively. Fast resting pulse rate was associated with a moderate increased risk of lipid metabolic dysfunctions in rural adults. However, resting pulse rate as an indicator has limited potential for screening the risk of lipid metabolic dysfunctions.

  8. Standard Metabolic Rate (SMR) is inversely related to erythrocyte and genome size in allopolyploid fish of the Cobitis taenia hybrid complex

    OpenAIRE

    Maciak, S.; Janko, K. (Karel); Kotusz, J.; Choleva, L. (Lukáš); Boron, A.; Juchno, D.; Kujawa, R.; Kozlowski, J.; Konarzewski, M.

    2011-01-01

    As a first approximation, whole-body metabolic rate can be considered as the sum of metabolic rates of constituent cells. Yet, among several current explanations of metabolic rate scaling, only two explicitly invoke cell architecture of organisms: (1) the Metabolic Theory of Ecology, which predicts size invariance of metabolically active cells, such as erythrocytes and (2) the cell metabolism hypothesis postulating partial dependence of metabolic scaling on the cell size (CS), which is mediat...

  9. Spatial variation in the relationship between performance and metabolic rate in wild juvenile Atlantic salmon

    Science.gov (United States)

    Grethe Robertsen; John D. Armstrong; Keith H. Nislow; Ivar Herfindal; Simon McKelvey; Sigurd Einum; Martin. Genner

    2014-01-01

    Maintenance of metabolic rate (MR, the energy cost of self-maintenance) is linked to behavioural traits and fitness and varies substantially within populations. Despite having received much attention, the causes and consequences of this variation remain obscure. Theoretically, such within-population variation in fitness-related traits can be maintained by environmental...

  10. [Evaluation of metabolic rate for a correct risk assessment of thermal environments].

    Science.gov (United States)

    Del Ferraro, Simona; Molinaro, V

    2010-01-01

    The new law n.81/2008 recognises microclimate as one of physical agents for which risk assessment becomes obligatory. To achieve this it is necessary to evaluate suitable indices, based on heat balance equation, which depend on six parameters: the first four are related to thermal environment and the last two are related to the worker (metabolic rate and thermal insulation). The first four parameters are directly measurable in situ by using a multiple data acquisition unit provided with suitable sensors. Parameters related to the worker are not directly measurable. This aspect represents one of the problems which can lead to an inaccurate risk assessment. Aim of the paper was to identify a method which leads to a correct evaluation of the metabolic rate related to the worker under study. It was decided to follow the procedures described by the standard UNI EN ISO 8996:2005 which presents four different levels to evaluate metabolic rate, each one with an increasing degree of accuracy. Seven workers were selected: three performed light tasks and the other four did heavy work. The study showed that the results appear to be in acceptable agreement in the case of light work while there were detectable differences in value for heavy tasks. The Authors believe it is necessary to stress the importance of a suitable estimation of the metabolic rate in order to carry out a correct risk assessment which quantifies the risk exactly.

  11. Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

    Directory of Open Access Journals (Sweden)

    Schilling Brian K

    2009-04-01

    Full Text Available Abstract Correction to Richard J Bloomer, Kelsey H Fisher-Wellman, Kelley G Hammond, Brian K Schilling, Adrianna A Weber and Bradford J Cole: Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men. Journal of the International Society of Sports Nutrition 2009, 6: 4

  12. Heritability of flight and resting metabolic rates in the Glanville fritillary butterfly.

    Science.gov (United States)

    Mattila, A L K; Hanski, I

    2014-08-01

    Dispersal capacity is a key life-history trait especially in species inhabiting fragmented landscapes. Evolutionary models predict that, given sufficient heritable variation, dispersal rate responds to natural selection imposed by habitat loss and fragmentation. Here, we estimate phenotypic variance components and heritability of flight and resting metabolic rates (RMRs) in an ecological model species, the Glanville fritillary butterfly, in which flight metabolic rate (FMR) is known to correlate strongly with dispersal rate. We modelled a two-generation pedigree with the animal model to distinguish additive genetic variance from maternal and common environmental effects. The results show that FMR is significantly heritable, with additive genetic variance accounting for about 40% of total phenotypic variance; thus, FMR has the potential to respond to selection on dispersal capacity. Maternal influences on flight metabolism were negligible. Heritability of flight metabolism was context dependent, as in stressful thermal conditions, environmentally induced variation dominated over additive genetic effects. There was no heritability in RMR, which was instead strongly influenced by maternal effects. This study contributes to a mechanistic understanding of the evolution of dispersal-related traits, a pressing question in view of the challenges posed to many species by changing climate and fragmentation of natural habitats. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  13. Metabolic rate and clothing insulation data of children and adolescents during various school activities

    NARCIS (Netherlands)

    Havenith, G.

    2007-01-01

    Data on metabolic rates (n = 0;81) and clothing insulation (n = 96) of school children and adolescents (A, primary school: age 9-10; B, primary school: age 10-11 year; C, junior vocational (technical) education: age 13-16 (lower level); D, same as C but at advanced level; and E, senior vocational

  14. Basal metabolic rate scaled to body mass between species by the ...

    African Journals Online (AJOL)

    This implies that the whole body fractal vascular dimension D is also applicable to all organs or collections of organs such as the viscera and skeletal muscle. The principal reason that basal metabolic rate (BMR) and MMR scale with different power exponents to whole body mass is that MMR is due mainly to respiration in ...

  15. Vitamin C improves basal metabolic rate and lipid profile in alloxan ...

    Indian Academy of Sciences (India)

    Diabetes mellitus (DM) is a multi-factorial disease which is characterized by hyperglycaemia, lipoprotein abnormalities and oxidative stress. This study evaluated effect of oral vitamin C administration on basal metabolic rate and lipid profile of alloxan-induced diabetic rats. Vitamin C was administered at 200 mg/kg body wt.

  16. Metabolic Syndrome and Short-Term Heart Rate Variability in Adults with Intellectual Disabilities

    Science.gov (United States)

    Chang, Yaw-Wen; Lin, Jin-Ding; Chen, Wei-Liang; Yen, Chia-Feng; Loh, Ching-Hui; Fang, Wen-Hui; Wu, Li-Wei

    2012-01-01

    Metabolic syndrome (MetS) increases the risk of cardiovascular events. Heart rate variability (HRV) represents autonomic functioning, and reduced HRV significantly increases cardiovascular mortality. The aims of the present paper are to assess the prevalence of MetS in adults with intellectual disabilities (ID), the difference in short-term HRV…

  17. Physiological plasticity of metabolic rates in the invasive honey bee and an endemic Australian bee species.

    Science.gov (United States)

    Tomlinson, Sean; Dixon, Kingsley W; Didham, Raphael K; Bradshaw, S Don

    2015-12-01

    Seasonal variation in metabolic rate and evaporative water loss as a function of ambient temperature were compared in two species of bees. The endemic blue-banded bee, Amegilla chlorocyanea, is a solitary species that is an important pollinator in the south-west Australian biodiversity hotspot. Responses were compared with the European honeybee, Apis mellifera, naturalised in Western Australia almost 200 years ago. Metabolic rate increased exponentially with temperature to a peak in both species, and then declined rapidly, with unique scaling exponents and peaks for all species-by-season comparisons. Early in the austral summer, Apis was less thermally tolerant than Amegilla, but the positions reversed later in the foraging season. There were also significant exponential increases in evaporative water loss with increasing temperature, and both season and species contributed to significantly different responses. Apis maintained relatively consistent thermal performance of metabolic rate between seasons, but at the expense of increased rates of evaporative water loss later in summer. In contrast, Amegilla had dramatically increased metabolic requirements later in summer, but maintained consistent thermal performance of evaporative water loss. Although both species acclimated to higher thermal tolerance, the physiological strategies underpinning the acclimation differed. These findings may have important implications for understanding the responses of these and other pollinators to changing environments and for their conservation management.

  18. The relationship between basal metabolic rate and daily energy expenditure in birds and mammals

    NARCIS (Netherlands)

    Ricklefs, RE; Konarzewski, M; Daan, S

    We examined the relationship between daily energy expenditure (DEE) and basal metabolic rate (BMR) in birds and mammals. Two models of the relationship between DEE and BMR were distinguished: a ''shared pathways'' model in which DEE replaces BMR in the active organism and a ''partitioned pathways''

  19. Using in vitro derived enzymatic reaction rates of metabolism to inform pesticide body burdens in amphibians.

    Science.gov (United States)

    Glinski, Donna A; Henderson, W Matthew; Van Meter, Robin J; Purucker, S Thomas

    2018-02-13

    Understanding how pesticide exposure to non-target species influences toxicity is necessary to accurately assess the ecological risks these compounds pose. To assess the potential metabolic activation of broad use pesticides in amphibians, in vitro and in vivo metabolic rate constants were derived from toad (Anaxyrus terrestris) livers in experiments measuring the depletion of atrazine (ATZ), triadimefon (TDN), and fipronil (FIP) as well as formation of their metabolites. To determine the predictability of these in vitro derived rate constants, Fowler's toads (Anaxyrus fowleri) were exposed to soil contaminated with each of the pesticides at maximum application rate. Desethyl atrazine (DEA) and deisopropyl atrazine (DIA), both metabolites of ATZ, exhibited similar velocities (V max ) while the K M constant for DIA was two times higher than DEA. TDN was metabolized into two diastereomers of triadimenol (TDL A and TDL B), where TDL B had a V max around two times higher than TDL A. The metabolite fipronil sulfone's V max and K M were 150 pmol min -1  mg -1 and 29 μM, respectively. While intrinsic clearance rates for the pesticides ranged from 0.54 to 38.31 mL min -1  kg -1 . Thus, gaining knowledge on differences in metabolism of pesticides within amphibians is important in estimating risk to these non-target species since the inherent toxicity of metabolites can differ from the parent compound. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Metabolic Rate Calibrates the Molecular Clock: Reconciling Molecular and Fossil Estimates of Evolutionary Divergence

    OpenAIRE

    Gillooly, James F.; Andrew P. Allen; West, Geoffrey B.; Brown, James H.

    2004-01-01

    Observations that rates of molecular evolution vary widely within and among lineages have cast doubts upon the existence of a single molecular clock. Differences in the timing of evolutionary events estimated from genetic and fossil evidence have raised further questions about the existence of molecular clocks and their use. Here we present a model of nucleotide substitution that combines new theory on metabolic rate with the now classic neutral theory of molecular evolution. The model quanti...

  1. Individual (co)variation in standard metabolic rate, feeding rate, and exploratory behavior in wild-caught semiaquatic salamanders.

    Science.gov (United States)

    Gifford, Matthew E; Clay, Timothy A; Careau, Vincent

    2014-01-01

    Repeatability is an important concept in evolutionary analyses because it provides information regarding the benefit of repeated measurements and, in most cases, a putative upper limit to heritability estimates. Repeatability (R) of different aspects of energy metabolism and behavior has been demonstrated in a variety of organisms over short and long time intervals. Recent research suggests that consistent individual differences in behavior and energy metabolism might covary. Here we present new data on the repeatability of body mass, standard metabolic rate (SMR), voluntary exploratory behavior, and feeding rate in a semiaquatic salamander and ask whether individual variation in behavioral traits is correlated with individual variation in metabolism on a whole-animal basis and after conditioning on body mass. All measured traits were repeatable, but the repeatability estimates ranged from very high for body mass (R = 0.98), to intermediate for SMR (R = 0.39) and food intake (R = 0.58), to low for exploratory behavior (R = 0.25). Moreover, repeatability estimates for all traits except body mass declined over time (i.e., from 3 to 9 wk), although this pattern could be a consequence of the relatively low sample size used in this study. Despite significant repeatability in all traits, we find little evidence that behaviors are correlated with SMR at the phenotypic and among-individual levels when conditioned on body mass. Specifically, the phenotypic correlations between SMR and exploratory behavior were negative in all trials but significantly so in one trial only. Salamanders in this study showed individual variation in how their exploratory behavior changed across trials (but not body mass, SMR, and feed intake), which might have contributed to observed changing correlations across trials.

  2. Effects of NaCl on metabolic heat evolution rates by barley roots

    Science.gov (United States)

    Criddle, R. S.; Hansen, L. D.; Breidenbach, R. W.; Ward, M. R.; Huffaker, R. C.

    1989-01-01

    The effect of salinity stress on metabolic heat output of barley (Hordeum vulgare L.) root tips was measured by isothermal microcalorimetry. Several varieties differing in tolerance to salinity were compared and differences quantified. Two levels of inhibition by increasing salt were found. Following the transition from the initial rate of the first level, inhibition remained at about 50% with further increases in salt concentration up to 150 millimolar. The concentration of salt required to inhibit to this level was cultivar dependent. At highter concentrations (>150 millimolar) of salt, metabolism was further decreased. This decrease was not cultivar dependent. The decreased rate of metabolic heat output at the first transition could be correlated with decreases in uptake of NO3-, NH4+, and Pi that occurred as the salt concentration was increased. The high degree of dependence of the inhibition of metabolic heat output on NaCl concentration points to a highly cooperative reaction responsible for the general inhibition of metabolism and nutrient uptake. The time required to attain the first level of salt inhibition is less than 20 minutes. Inhibition of root tips was not reversible by washing with salt free solutions. In addition to revealing these features of salt inhibition, isothermal microcalorimetry is a promising method for convenient and rapid determination of varietal differences in response to increasing salinity.

  3. Standard metabolic rates of Lepisma saccharina and Thermobia domestica: effects of temperature and mass.

    Science.gov (United States)

    DeVries, Zachary C; Appel, Arthur G

    2013-06-01

    Silverfish, Lepisma saccharina L., and firebrats, Thermobia domestica (Packard), are two common thysanuran pests in the urban environment. Both species can survive for extended periods without feeding, suggesting that they have some metabolic modifications compared with other insects which cannot tolerate extended starvation. To investigate potential metabolic modifications and to compare silverfish and firebrats, we measured the standard metabolic rate of both species at five temperatures (10, 20, 25, 30, 40°C) across a range of body masses using closed system respirometry. Temperature had a stronger effect on firebrat mass specific [Formula: see text] (mlg(-1)h(-1)) than on silverfish mass specific [Formula: see text] for adults (>0.00700g: firebrat Q10=2.32, silverfish Q10=2.07) and immatures (metabolic substrate with temperature. These results are interpreted with respect to the life histories and environment of both species. Finally, metabolic rates are compared with those of ticks and other arthropods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Experimental study on trace chemical contaminant generation rates of human metabolism in spacecraft crew module

    Science.gov (United States)

    Lihua, Guo; Xinxing, He; Guoxin, Xu; Xin, Qi

    2012-12-01

    Trace chemical contaminants generated by human metabolism is a major source of contamination in spacecraft crew module. In this research, types and generation rates of pollutants from human metabolism were determined in the Chinese diets. Expired air, skin gas, and sweat of 20 subjects were analyzed at different exercise states in a simulated module. The exercise states were designed according to the basic activities in the orbit of astronauts. Qualitative and quantitative analyses of contaminants generated by human metabolic were performed with gas chromatography/mass spectrometry, gas chromatography and UV spectrophotometer. Sixteen chemical compounds from metabolic sources were found. With the increase in physical load, the concentrations of chemical compounds from human skin and expired air correspondingly increased. The species and the offgassing rates of pollutants from human metabolism are different among the Chinese, Americans and the Russians due to differences in ethnicity and dietary customs. This research provides data to aid in the design, development and operation of China's long duration space mission.

  5. Mechanistic drivers of flexibility in summit metabolic rates of small birds.

    Directory of Open Access Journals (Sweden)

    David Swanson

    Full Text Available Flexible metabolic phenotypes allow animals to adjust physiology to better fit ecological or environmental demands, thereby influencing fitness. Summit metabolic rate (Msum = maximal thermogenic capacity is one such flexible trait. Skeletal muscle and heart masses and myocyte metabolic intensity are potential drivers of Msum flexibility in birds. We examined correlations of skeletal muscle and heart masses and pectoralis muscle citrate synthase (CS activity (an indicator of cellular metabolic intensity with Msum in house sparrows (Passer domesticus and dark-eyed juncos (Junco hyemalis to determine whether these traits are associated with Msum variation. Pectoralis mass was positively correlated with Msum for both species, but no significant correlation remained for either species after accounting for body mass (Mb variation. Combined flight and leg muscle masses were also not significantly correlated with Msum for either species. In contrast, heart mass was significantly positively correlated with Msum for juncos and nearly so (P = 0.054 for sparrows. Mass-specific and total pectoralis CS activities were significantly positively correlated with Msum for sparrows, but not for juncos. Thus, myocyte metabolic intensity influences Msum variation in house sparrows, although the stronger correlation of total (r = 0.495 than mass-specific (r = 0.378 CS activity with Msum suggests that both pectoralis mass and metabolic intensity impact Msum. In contrast, neither skeletal muscle masses nor pectoralis metabolic intensity varied with Msum in juncos. However, heart mass was associated with Msum variation in both species. These data suggest that drivers of metabolic flexibility are not uniform among bird species.

  6. Mechanistic Drivers of Flexibility in Summit Metabolic Rates of Small Birds

    Science.gov (United States)

    Swanson, David; Zhang, Yufeng; King, Marisa

    2014-01-01

    Flexible metabolic phenotypes allow animals to adjust physiology to better fit ecological or environmental demands, thereby influencing fitness. Summit metabolic rate (Msum = maximal thermogenic capacity) is one such flexible trait. Skeletal muscle and heart masses and myocyte metabolic intensity are potential drivers of Msum flexibility in birds. We examined correlations of skeletal muscle and heart masses and pectoralis muscle citrate synthase (CS) activity (an indicator of cellular metabolic intensity) with Msum in house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis) to determine whether these traits are associated with Msum variation. Pectoralis mass was positively correlated with Msum for both species, but no significant correlation remained for either species after accounting for body mass (Mb) variation. Combined flight and leg muscle masses were also not significantly correlated with Msum for either species. In contrast, heart mass was significantly positively correlated with Msum for juncos and nearly so (P = 0.054) for sparrows. Mass-specific and total pectoralis CS activities were significantly positively correlated with Msum for sparrows, but not for juncos. Thus, myocyte metabolic intensity influences Msum variation in house sparrows, although the stronger correlation of total (r = 0.495) than mass-specific (r = 0.378) CS activity with Msum suggests that both pectoralis mass and metabolic intensity impact Msum. In contrast, neither skeletal muscle masses nor pectoralis metabolic intensity varied with Msum in juncos. However, heart mass was associated with Msum variation in both species. These data suggest that drivers of metabolic flexibility are not uniform among bird species. PMID:24992186

  7. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Jon C Svendsen

    Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

  8. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Science.gov (United States)

    Svendsen, Jon C; Genz, Janet; Anderson, W Gary; Stol, Jennifer A; Watkinson, Douglas A; Enders, Eva C

    2014-01-01

    Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons). Using juvenile lake sturgeon (Acipenser fulvescens), the objective of this study was to test four hypotheses: 1) A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2) A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3) measurements of forced maximum metabolic rate (MMR(F)) are repeatable in individual fish; and 4) MMR(F) correlates positively with spontaneous maximum metabolic rate (MMR(S)). Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F). Trials lasting 24 h were used to measure standard metabolic rate (SMR) and MMR(S). Repeatability and correlations between MMR(F) and MMR(S) were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat))), demonstrating oxygen regulation. In contrast, MMR(F) was affected by hypoxia and decreased across the range from 100% O(2sat) to 70% O(2sat). MMR(F) was repeatable in individual fish, and MMR(F) correlated positively with MMR(S), but the relationships between MMR(F) and MMR(S) were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor). Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F) and MMR(S) support the conjecture that MMR(F) represents a measure of organism performance that could be a target of natural selection.

  9. Effect of dietary fatty acids on metabolic rate and nonshivering thermogenesis in golden hamsters.

    Science.gov (United States)

    Jefimow, Małgorzata; Wojciechowski, Michał S

    2014-02-01

    Hibernating rodents prior to winter tend to select food rich in polyunsaturated fatty acids (PUFA). Several studies found that such diet may positively affect their winter energy budget by enhancing torpor episodes. However, the effect of composition of dietary fatty acids (FA) on metabolism of normothermic heterotherms is poorly understood. Thus we tested whether diets different in FA composition affect metabolic rate (MR) and the capacity for nonshivering thermogenesis (NST) in normothermic golden hamsters (Mesocricetus auratus). Animals were housed in outdoor enclosures from May 2010 to April 2011 and fed a diet enriched with PUFA (i.e., standard food supplemented weekly with sunflower and flax seeds) or with saturated and monounsaturated fatty acids (SFA/MUFA, standard food supplemented with mealworms). Since diet rich in PUFA results in lower MR in hibernating animals, we predicted that PUFA-rich diet would have similar effect on MR of normothermic hamsters, that is, normothermic hamsters on the PUFA diet would have lower metabolic rate in cold and higher NST capacity than hamsters supplemented with SFA/MUFA. Indeed, in winter resting metabolic rate (RMR) below the lower critical temperature was higher and NST capacity was lower in SFA/MUFA-supplemented animals than in PUFA-supplemented ones. These results suggest that the increased capacity for NST in PUFA-supplemented hamsters enables them lower RMR below the lower critical temperature of the thermoneural zone. © 2013 Wiley Periodicals, Inc.

  10. Ecological Influences and Morphological Correlates of Resting and Maximal Metabolic Rates across Teleost Fish Species.

    Science.gov (United States)

    Killen, Shaun S; Glazier, Douglas S; Rezende, Enrico L; Clark, Timothy D; Atkinson, David; Willener, Astrid S T; Halsey, Lewis G

    2016-05-01

    Rates of aerobic metabolism vary considerably across evolutionary lineages, but little is known about the proximate and ultimate factors that generate and maintain this variability. Using data for 131 teleost fish species, we performed a large-scale phylogenetic comparative analysis of how interspecific variation in resting metabolic rates (RMRs) and maximum metabolic rates (MMRs) is related to several ecological and morphological variables. Mass- and temperature-adjusted RMR and MMR are highly correlated along a continuum spanning a 30- to 40-fold range. Phylogenetic generalized least squares models suggest that RMR and MMR are higher in pelagic species and that species with higher trophic levels exhibit elevated MMR. This variation is mirrored at various levels of structural organization: gill surface area, muscle protein content, and caudal fin aspect ratio (a proxy for activity) are positively related with aerobic capacity. Muscle protein content and caudal fin aspect ratio are also positively correlated with RMR. Hypoxia-tolerant lineages fall at the lower end of the metabolic continuum. Different ecological lifestyles are associated with contrasting levels of aerobic capacity, possibly reflecting the interplay between selection for increased locomotor performance on one hand and tolerance to low resource availability, particularly oxygen, on the other. These results support the aerobic capacity model of the evolution of endothermy, suggesting elevated body temperatures evolved as correlated responses to selection for high activity levels.

  11. On the depth and scale of metabolic rate variation: scaling of oxygen consumption rates and enzymatic activity in the Class Cephalopoda (Mollusca).

    Science.gov (United States)

    Seibel, Brad A

    2007-01-01

    Recent ecological theory depends, for predictive power, on the apparent similarity of metabolic rates within broad taxonomic or functional groups of organisms (e.g. invertebrates or ectotherms). Such metabolic commonality is challenged here, as I demonstrate more than 200-fold variation in metabolic rates independent of body mass and temperature in a single class of animals, the Cephalopoda, over seven orders of magnitude size range. I further demonstrate wide variation in the slopes of metabolic scaling curves. The observed variation in metabolism reflects differential selection among species for locomotory capacity rather than mass or temperature constraints. Such selection is highest among epipelagic squids (Lolignidae and Ommastrephidae) that, as adults, have temperature-corrected metabolic rates higher than mammals of similar size.

  12. Inter-sexual differences in resting metabolic rates in the Texas tarantula, Aphonopelma anax.

    Science.gov (United States)

    Shillington, Cara

    2005-12-01

    Intra-specific variation in life history and mating strategies can lead to differences in energy allocation and expenditure in males and females. This may, in turn, explain large-scale evolutionary patterns. In this study, I investigated the effects of body mass, temperature and sex on resting metabolic rates (RMRs) in sexually mature male and female tarantulas (Aphonopelma anax (Chamberlin)), a species that exhibits extreme inter-sexual differences in life history after reaching sexual maturity. RMRs were measured as rates of CO(2) production in an open-flow respirometry system at 20, 25, 30 and 35 degrees C. These temperatures are typical to what this species experiences under natural conditions. In addition, a respiratory quotient (RQ) of 0.92 was calculated from rates of CO(2) production and O(2) consumption in a closed, constant-volume respirometry system. As expected, RMRs increased with increasing temperature and body mass. However, after adjusting for the influence of body mass, males had substantially higher metabolic rates than females at each temperature. This higher metabolic rate is proposed as an adaptive strategy to support higher energetic demands for males during their active, locomotory search for females during the mating season.

  13. A CMI (cell metabolic indicator)-based controller for achieving high growth rate Escherichia coli cultures.

    Science.gov (United States)

    Pepper, Matthew E; Wang, Li; Padmakumar, Ajay; Burg, Timothy C; Harcum, Sarah W; Groff, Richard E

    2014-01-01

    A large fraction of biopharmaceuticals are produced in Escherichia coli, where each new product and strain currently requires a high degree of growth characterization in benchtop and industrial bioreactors to achieve economical production protocols. The capability to use a standard set of sensors to characterize a system quickly without the need to conduct numerous experiments to determine stable growth rate for the strain would significantly decrease development time. This paper presents a cell metabolic indicator (CMI) which provides better insight into the E. coli metabolism than a growth rate value. The CMI is the ratio of the oxygen uptake rate (OUR) of the culture and the base addition rate (BAR) required to keep pH at a desired setpoint. The OUR and BAR are measured using a off-gas sensor and pH probe, respectively, and thus the CMI can be computed online. Experimental results demonstrate the relationship between CMI and the different cell metabolic states. A previously published model is augmented with acid production dynamics, allowing for comparison of the CMI-based controller with an open-loop controller in simulation. The CMI-based controller required little a priori knowledge about the E. coli strain in order to achieve a high growth rate. Since many different types of cells exhibit similar behaviors, the CMI concept can be extended to mammalian and stem cells.

  14. Isometric size-scaling of metabolic rate and the size abundance distribution of phytoplankton

    Science.gov (United States)

    Huete-Ortega, María; Cermeño, Pedro; Calvo-Díaz, Alejandra; Marañón, Emilio

    2012-01-01

    The relationship between phytoplankton cell size and abundance has long been known to follow regular, predictable patterns in near steady-state ecosystems, but its origin has remained elusive. To explore the linkage between the size-scaling of metabolic rate and the size abundance distribution of natural phytoplankton communities, we determined simultaneously phytoplankton carbon fixation rates and cell abundance across a cell volume range of over six orders of magnitude in tropical and subtropical waters of the Atlantic Ocean. We found an approximately isometric relationship between carbon fixation rate and cell size (mean slope value: 1.16; range: 1.03–1.32), negating the idea that Kleiber's law is applicable to unicellular autotrophic protists. On the basis of the scaling of individual resource use with cell size, we predicted a reciprocal relationship between the size-scalings of phytoplankton metabolic rate and abundance. This prediction was confirmed by the observed slopes of the relationship between phytoplankton abundance and cell size, which have a mean value of −1.15 (range: −1.29 to −0.97), indicating that the size abundance distribution largely results from the size-scaling of metabolic rate. Our results imply that the total energy processed by carbon fixation is constant along the phytoplankton size spectrum in near steady-state marine ecosystems. PMID:22171079

  15. Seasonal variation in metabolic rate, flight activity and body size of Anopheles gambiae in the Sahel.

    Science.gov (United States)

    Huestis, Diana L; Yaro, Alpha S; Traoré, Adama I; Dieter, Kathryne L; Nwagbara, Juliette I; Bowie, Aleah C; Adamou, Abdoulaye; Kassogué, Yaya; Diallo, Moussa; Timbiné, Seydou; Dao, Adama; Lehmann, Tovi

    2012-06-15

    Malaria in Africa is vectored primarily by the Anopheles gambiae complex. Although the mechanisms of population persistence during the dry season are not yet known, targeting dry season mosquitoes could provide opportunities for vector control. In the Sahel, it appears likely that M-form A. gambiae survive by aestivation (entering a dormant state). To assess the role of eco-physiological changes associated with dry season survival, we measured body size, flight activity and metabolic rate of wild-caught mosquitoes throughout 1 year in a Sahelian locality, far from permanent water sources, and at a riparian location adjacent to the Niger River. We found significant seasonal variation in body size at both the Sahelian and riparian sites, although the magnitude of the variation was greater in the Sahel. For flight activity, significant seasonality was only observed in the Sahel, with increased flight activity in the wet season when compared with that just prior to and throughout the dry season. Whole-organism metabolic rate was affected by numerous biotic and abiotic factors, and a significant seasonal component was found at both locations. However, assay temperature accounted completely for seasonality at the riparian location, while significant seasonal variation remained after accounting for all measured variables in the Sahel. Interestingly, we did not find that mean metabolic rate was lowest during the dry season at either location, contrary to our expectation that mosquitoes would conserve energy and increase longevity by reducing metabolism during this time. These results indicate that mosquitoes may use mechanisms besides reduced metabolic rate to enable survival during the Sahelian dry season.

  16. Regular monitoring of breast-feeding rates: feasible and sustainable. The Emilia-Romagna experience.

    Science.gov (United States)

    Di Mario, Simona; Borsari, Silvana; Verdini, Eleonora; Battaglia, Sergio; Cisbani, Luca; Sforza, Stefano; Cuoghi, Chiara; Basevi, Vittorio

    2017-08-01

    An efficient breast-feeding monitoring system should be in place in every country to assist policy makers and health professionals plan activities to reach optimal breast-feeding rates. Design/Setting/Subjects From March to June 2015, breast-feeding rates at 3 and 5 months of age were monitored in Emilia-Romagna, an Italian region, using four questions added to a newly developed paediatric immunization database with single records for each individual. Data were collected at primary-care centres. Breast-feeding definitions and 24 h recall as recommended by the WHO were used. Direct age standardization was applied to breast-feeding rates. Record linkage with the medical birth database was attempted to identify maternal, pregnancy and delivery factors associated with full breast-feeding rates at 3 and 5 months of age. Data on breast-feeding were collected for 14044 infants. The mean regional full breast-feeding rate at 3 months was 52 %; differences between local health authorities ranged from 42 to 62 %. At 5 months of age, the mean regional full breast-feeding rate dropped to 33 % (range between local health authorities: 26 to 46 %). Record linkage with the birth certificate database was successful for 93 % of records. Total observations more than doubled with respect to the previous regional survey. The new monitoring system implemented in 2015 in Emilia-Romagna region, totally integrated with the immunization database, has proved to be feasible, sustainable and more efficient than the previous one. This system can be a model for other regions and countries where the vast majority of mothers obtain vaccinations from public health facilities and that already have an immunization database in place.

  17. Metabolic flux analysis for optimizing the specific growth rate of recombinant Aspergillus niger.

    Science.gov (United States)

    Gheshlaghi, R; Scharer, J M; Moo-Young, M; Douglas, P L

    2007-11-01

    A comprehensive metabolic network comprising three intracellular compartments (cytoplasm, mitochondrion and peroxisome) was developed for Aspergillus niger. The metabolic flux network includes carbohydrate and amino acid metabolism in both anabolic and catabolic reactions. Linear programming was used for the optimization of the specific growth rates in combination with 37 measured input and output fluxes of the key metabolites to evaluate corresponding intracellular flux distributions throughout the batch fermentations. Logarithmic sensitivity analysis revealed that the addition of proline, alanine and glutamate benefited growth in defined media. The experimental observations and flux analysis showed that tyrosine was a potential candidate for biomass production improvement. Model predictions was verified by conducting batch and fed-batch fermentations and it was found that the addition of the four amino acids according to the predetermined schedule resulted in a 44 and 41% improvements in biomass and recombinant protein productions, respectively.

  18. Maximum entropy modeling of metabolic networks by constraining growth-rate moments predicts coexistence of phenotypes

    Science.gov (United States)

    De Martino, Daniele

    2017-12-01

    In this work maximum entropy distributions in the space of steady states of metabolic networks are considered upon constraining the first and second moments of the growth rate. Coexistence of fast and slow phenotypes, with bimodal flux distributions, emerges upon considering control on the average growth (optimization) and its fluctuations (heterogeneity). This is applied to the carbon catabolic core of Escherichia coli where it quantifies the metabolic activity of slow growing phenotypes and it provides a quantitative map with metabolic fluxes, opening the possibility to detect coexistence from flux data. A preliminary analysis on data for E. coli cultures in standard conditions shows degeneracy for the inferred parameters that extend in the coexistence region.

  19. Glutamate dehydrogenase is essential to sustain neuronal oxidative energy metabolism during stimulation

    DEFF Research Database (Denmark)

    Hohnholt, Michaela C; Andersen, Vibe H; Andersen, Jens V

    2017-01-01

    -labelled glutamine and glucose. We observed a severely reduced oxidative glutamine metabolism during glucose deprivation in synaptosomes and cultured neurons not expressing GDH. In contrast, in the presence of glucose, glutamine metabolism was not affected by the lack of GDH expression. Respiration fuelled...... by glutamate was significantly lower in brain mitochondria from GDH KO mice and synaptosomes were not able to increase their respiration upon an elevated energy demand. The role of GDH for metabolism of glutamine and the respiratory capacity underscore the importance of GDH for neurons particularly during...

  20. The implications of reduced metabolic rate in resource-limited corals.

    Science.gov (United States)

    Jacobson, Lianne M; Edmunds, Peter J; Muller, Erik B; Nisbet, Roger M

    2016-03-01

    Many organisms exhibit depressed metabolism when resources are limited, a change that makes it possible to balance an energy budget. For symbiotic reef corals, daily cycles of light and periods of intense cloud cover can be chronic causes of food limitation through reduced photosynthesis. Furthermore, coral bleaching is common in present-day reefs, creating a context in which metabolic depression could have beneficial value to corals. In the present study, corals (massive Porites spp.) were exposed to an extreme case of resource limitation by starving them of food and light for 20 days. When resources were limited, the corals depressed area-normalized respiration to 37% of initial rates, and coral biomass declined to 64% of initial amounts, yet the corals continued to produce skeletal mass. However, the declines in biomass cannot account for the declines in area-normalized respiration, as mass-specific respiration declined to 30% of the first recorded time point. Thus, these corals appear to be capable of metabolic depression. It is possible that some coral species are better able to depress metabolic rates than others; such variation could explain differential survival during conditions that limit resources (e.g. shading). Furthermore, we found that maintenance of existing biomass, in part, supports the production of skeletal mass. This association could be explained if maintenance supplies needed energy (e.g. ATP) or inorganic carbon (i.e. CO2) that otherwise limits the production of skeletal mass. Finally, the observed metabolic depression can be explained as a change in pool sizes, and does not require a change in metabolic rules. © 2016. Published by The Company of Biologists Ltd.

  1. Ivabradine reduces heart rate while preserving metabolic fluxes and energy status of healthy normoxic working hearts.

    Science.gov (United States)

    Lauzier, Benjamin; Vaillant, Fanny; Gélinas, Roselle; Bouchard, Bertrand; Brownsey, Roger; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine

    2011-03-01

    Heart rate reduction (HRR) is an important target in the management of patients with chronic stable angina. Most available drugs for HRR, such as β-blockers, have adverse effects, including on cardiac energy substrate metabolism, a well-recognized determinant of cardiac homeostasis. This study aimed at 1) testing whether HRR by ivabradine (IVA) alters substrate metabolism in the healthy normoxic working heart and 2) comparing the effect of IVA with that of the β-blocker metoprolol (METO). This was assessed using our well-established model of ex vivo mouse heart perfusion in the working mode, which enables concomitant evaluation of myocardial contractility and metabolic fluxes using (13)C-labeled substrates. Hearts were perfused in the absence (controls; n = 10) or presence of IVA (n = 10, 3 μM) with or without atrial pacing to abolish HRR in the IVA group. IVA significantly reduced HR (35 ± 5%) and increased stroke volume (39 ± 9%) while maintaining similar cardiac output, contractility, power, and efficiency. Effects of IVA on HR and stroke volume were reversed by atrial pacing. At the metabolic level, IVA did not impact on substrate selection to citrate formation, rates of glycolysis, or tissue levels of high-energy phosphates. In contrast, METO, at concentrations up to 40 μM, decreased markedly cardiac function (flow: 25 ± 6%; stroke volume: 30 ± 10%; contractility: 31 ± 9%) as well as glycolysis (2.9-fold) but marginally affected HR. Collectively, these results demonstrate that IVA selectively reduces HR while preserving energy substrate metabolism of normoxic healthy working mouse hearts perfused ex vivo, a model that mimics to some extent the denervated transplanted heart. Our results provide the impetus for testing selective HRR by IVA on cardiac substrate metabolism in pathological models.

  2. Evaluation of rate law approximations in bottom-up kinetic models of metabolism

    DEFF Research Database (Denmark)

    Du, Bin; Zielinski, Daniel C.; Kavvas, Erol S.

    2016-01-01

    mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law...... concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations. Conclusions: Overall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux......Background: The mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws...

  3. Sustainable Use of Pesticide Applications in Citrus: A Support Tool for Volume Rate Adjustment

    Directory of Open Access Journals (Sweden)

    Cruz Garcerá

    2017-06-01

    Full Text Available Rational application of pesticides by properly adjusting the amount of product to the actual needs and specific conditions for application is a key factor for sustainable plant protection. However, current plant protection product (PPP labels registered for citrus in EU are usually expressed as concentration (%; rate/hl and/or as the maximum dose of product per unit of ground surface, without taking into account those conditions. In this work, the fundamentals of a support tool, called CitrusVol, developed to recommend mix volume rates in PPP applications in citrus orchards using airblast sprayers, are presented. This tool takes into consideration crop characteristics (geometry, leaf area density, pests, and product and application efficiency, and it is based on scientific data obtained previously regarding the minimum deposit required to achieve maximum efficacy, efficiency of airblast sprayers in citrus orchards, and characterization of the crop. The use of this tool in several commercial orchards allowed a reduction of the volume rate and the PPPs used in comparison with the commonly used by farmers of between 11% and 74%, with an average of 31%, without affecting the efficacy. CitrusVol is freely available on a website and in an app for smartphones.

  4. Effects of dietary trans fatty acids on fat accumulation and metabolic rate in rat.

    Science.gov (United States)

    Ochiai, Masaru; Fujii, Kazuma; Takeuchi, Hiroyuki; Matsuo, Tatsuhiro

    2013-01-01

    Dietary intake of high trans-fatty acids (TFAs) is well known to increase the risk of cardiovascular diseases. However, few reports demonstrated definitive relationships between dietary TFAs and obesity. In addition, the difference in the gastrointestinal absorption rate of TFAs containing oil from that of cis-FAs containing oil was not taken into consideration in many rat studies. In experiment A, we investigated the difference in the apparent absorption rate of TFAs containing oil from control oil. Hydrogenated rapeseed oil and a mixture of camellia oil and tristearin (90:10 [w/w]) were used as TFA-containing test oil and control oil, respectively. Ten Wistar rats were divided into the control group or TFA group, and fed the respective diet containing the control oil or the test oil for 1 week. The apparent absorption rates of these oils were measured by fecal fat excretion rate and dietary fat intake. The results showed a significantly lower gastrointestinal apparent absorption rate of the test oil (93.1%) than that of the control oil (96.2%). In consideration of the apparent absorption rate of these dietary oils, the effects of dietary TFAs on body fat accumulation and energy metabolism were investigated in rats. Twenty-eight Wistar rats were divided into the control group or the TFA group. Each group received an isoenergetic diet containing the control oil or the test oil for 8 weeks. Pre- and postprandial metabolic rates were measured between weeks 7 and 8. The test oil-based diet did not significantly influence body weight gain, fat accumulation, and metabolic rate. In contrast, liver weight, hepatic triglyceride content, and serum non-high density lipoprotein (HDL)-cholesterol (CHO)/HDL-CHO ratio were significantly higher in the TFA group than in the control group. In conclusion, these findings suggest that dietary TFAs did not influence body fat accumulation but increased the levels of risk markers of cardiovascular diseases.

  5. Assessing metabolic rate and indoor air quality with passive environmental sensors.

    Science.gov (United States)

    Ruiz, Iván; Sprowls, Mark; Deng, Yue; Kulick, Doina; Destaillats, Hugo; Forzani, Erica S

    2018-02-13

    The present work introduces the use of environmental sensors to assess indoor air quality (IAQ) in combination with human biometrics. The sensor array included temperature, relative humidity, carbon dioxide, and noise sensors. The array was used in a classroom as well as in a vehicle cabin to assess the indoor air quality and carbon dioxide production rate of individuals in a closed ventilation environment. Analysis of carbon dioxide production allowed for the quantification of the average metabolic rate of the group of individuals in the classroom, and for one individual in the vehicle cabin. These results yielded a mere 5% difference from the values assessed using commercial metabolic rate instruments, and averaged values from epidemiological studies. The results presented in this work verify the feasibility of determining an individual's metabolic rate using passive environmental sensors; these same sensors are able to provide a metric of indoor air quality that helps characterize the safety of the environment in which the individual is present. © 2018 IOP Publishing Ltd.

  6. Social sustainability in healthcare facilities: a rating tool for analysing and improving social aspects in environments of care.

    Science.gov (United States)

    Capolongo, Stefano; Gola, Marco; di Noia, Michela; Nickolova, Maria; Nachiero, Dario; Rebecchi, Andrea; Settimo, Gaetano; Vittori, Gail; Buffoli, Maddalena

    2016-01-01

    Nowadays several rating systems exist for the evaluation of the sustainability of buildings, but often their focus is limited to environmental and efficiency aspects. Hospitals are complex constructions in which many variables affect hospital processes. Therefore, a research group has developed a tool for the evaluation of sustainability in healthcare facilities. The paper analyses social sustainability issues through a tool which evaluates users' perception from a the quality and well-being perspective. It presents a hierarchical structure composed of a criteria and indicators system which is organised through a weighing system calculated by using the Analytic Network Process. The output is the definition of a tool which evaluates how Humanisation, Comfort and Distribution criteria can affect the social sustainability of a building. Starting from its application, it is evident that the instrument enables the improvement of healthcare facilities through several design and organisational suggestions for achieving healing and sustainable architectures.

  7. Consequences of complex environments: Temperature and energy intake interact to influence growth and metabolic rate.

    Science.gov (United States)

    Stahlschmidt, Zachary R; Jodrey, Alicia D; Luoma, Rachel L

    2015-09-01

    The field of comparative physiology has a rich history of elegantly examining the effects of individual environmental factors on performance traits linked to fitness (e.g., thermal performance curves for locomotion). However, animals live in complex environments wherein multiple environmental factors co-vary. Thus, we investigated the independent and interactive effects of temperature and energy intake on the growth and metabolic rate of juvenile corn snakes (Pantherophis guttatus) in the context of shifts in complex environments. Unlike previous studies that imposed constant or fluctuating temperature regimes, we manipulated the availability of preferred thermal microclimates (control vs. relatively warm regimes) for eight weeks and allowed snakes to behaviorally thermoregulate among microclimates. By also controlling for energy intake, we demonstrate an interactive effect of temperature and energy on growth-relevant temperature shifts had no effect on snakes' growth when energy intake was low and a positive effect on growth when energy intake was high. Thus, acclimation to relatively warm thermal options can result in increased rates of growth when food is abundant in a taxon in which body size confers fitness advantages. Temperature and energy also interactively influenced metabolic rate-snakes in the warmer temperature regime exhibited reduced metabolic rate (O2 consumption rate at 25 °C and 30 °C) if they had relatively high energy intake. Although we advocate for continued investigation into the effects of complex environments on other traits, our results indicate that warming may actually benefit important life history traits in some taxa and that metabolic shifts may underlie thermal acclimation. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Influence of ambient oxygenation and temperature on metabolic scope and scope for heart rate in the common sole Solea solea

    OpenAIRE

    Lefrancois, Christelle; Claireaux, Guy

    2003-01-01

    The objective of this study was to quantify the constraints exerted by temperature and oxygenation on both metabolic scope and scope for heart rate of the common sole Solea solea. We exposed sole to a large range of temperature and oxygenation conditions and a modelling procedure was implemented to describe metabolic and cardiac responses. Standard metabolic rate (SMR) rose exponentially from 4 to 24degreesC, whereas active metabolic rate (AMR) increased from 55.4 to 159.2 mgO(2) kg(-1) h(-1)...

  9. Low global sensitivity of metabolic rate to temperature in calcified marine invertebrates.

    Science.gov (United States)

    Watson, Sue-Ann; Morley, Simon A; Bates, Amanda E; Clark, Melody S; Day, Robert W; Lamare, Miles; Martin, Stephanie M; Southgate, Paul C; Tan, Koh Siang; Tyler, Paul A; Peck, Lloyd S

    2014-01-01

    Metabolic rate is a key component of energy budgets that scales with body size and varies with large-scale environmental geographical patterns. Here we conduct an analysis of standard metabolic rates (SMR) of marine ectotherms across a 70° latitudinal gradient in both hemispheres that spanned collection temperatures of 0-30 °C. To account for latitudinal differences in the size and skeletal composition between species, SMR was mass normalized to that of a standard-sized (223 mg) ash-free dry mass individual. SMR was measured for 17 species of calcified invertebrates (bivalves, gastropods, urchins and brachiopods), using a single consistent methodology, including 11 species whose SMR was described for the first time. SMR of 15 out of 17 species had a mass-scaling exponent between 2/3 and 1, with no greater support for a 3/4 rather than a 2/3 scaling exponent. After accounting for taxonomy and variability in parameter estimates among species using variance-weighted linear mixed effects modelling, temperature sensitivity of SMR had an activation energy (Ea) of 0.16 for both Northern and Southern Hemisphere species which was lower than predicted under the metabolic theory of ecology (Ea 0.2-1.2 eV). Northern Hemisphere species, however, had a higher SMR at each habitat temperature, but a lower mass-scaling exponent relative to SMR. Evolutionary trade-offs that may be driving differences in metabolic rate (such as metabolic cold adaptation of Northern Hemisphere species) will have important impacts on species abilities to respond to changing environments.

  10. Quantitative assessment of brain glucose metabolic rates using in vivo deuterium magnetic resonance spectroscopy.

    Science.gov (United States)

    Lu, Ming; Zhu, Xiao-Hong; Zhang, Yi; Mateescu, Gheorghe; Chen, Wei

    2017-11-01

    Quantitative assessment of cerebral glucose consumption rate (CMR glc ) and tricarboxylic acid cycle flux (V TCA ) is crucial for understanding neuroenergetics under physiopathological conditions. In this study, we report a novel in vivo Deuterium ( 2 H) MRS (DMRS) approach for simultaneously measuring and quantifying CMR glc and V TCA in rat brains at 16.4 Tesla. Following a brief infusion of deuterated glucose, dynamic changes of isotope-labeled glucose, glutamate/glutamine (Glx) and water contents in the brain can be robustly monitored from their well-resolved 2 H resonances. Dynamic DMRS glucose and Glx data were employed to determine CMR glc and V TCA concurrently. To test the sensitivity of this method in response to altered glucose metabolism, two brain conditions with different anesthetics were investigated. Increased CMR glc (0.46 vs. 0.28 µmol/g/min) and V TCA (0.96 vs. 0.6 µmol/g/min) were found in rats under morphine as compared to deeper anesthesia using 2% isoflurane. This study demonstrates the feasibility and new utility of the in vivo DMRS approach to assess cerebral glucose metabolic rates at high/ultrahigh field. It provides an alternative MRS tool for in vivo study of metabolic coupling relationship between aerobic and anaerobic glucose metabolisms in brain under physiopathological states.

  11. The optimal combination of standard metabolic rate and aerobic scope for somatic growth depends on food availability

    OpenAIRE

    Auer, Sonya K.; Salin, Karine; Rudolf, Agata Marta; Anderson, Graeme J.; Metcalfe, Neil B.

    2015-01-01

    Metabolic rates can vary as much as threefold among individuals of the same size and age in a population, but why such variation persists is unclear given that they determine the energetic cost of living. Relationships between standard metabolic rate (SMR), growth and survival can vary with environmental conditions, suggesting that the fitness consequences of a given metabolic phenotype may be context-dependent. Less attention has focused on the link between absolute aerobic scope (AS, the di...

  12. STARS: A Sustainability Assessment and Rating System for Colleges and Universities

    Science.gov (United States)

    Walton, Judy

    2008-01-01

    Given the rapid growth of sustainability initiatives at institutions of higher education in the United States, measuring and assessing progress toward sustainability goals has become increasingly important. While many institutions have undertaken campus-wide assessments of their progress toward sustainability, and while a variety of sustainability…

  13. Basal metabolic rate in relation to body composition and daily energy expenditure in the field vole, Microtus agrestis

    NARCIS (Netherlands)

    Meerlo, P; Bolle, L; Visser, GH; Masman, D; Daan, S

    1997-01-01

    Basal metabolic rate in the field vole (Microtus agrestis) was studied in relation to body composition and daily energy expenditure in the field Daily energy expenditure was measured by means of doubly labelled water ((D2O)-O-18). In the same individuals, basal metabolic rate was subsequently

  14. Neonatal environment exerts a sustained influence on the development of the intestinal microbiota and metabolic phenotype.

    Science.gov (United States)

    Merrifield, Claire A; Lewis, Marie C; Berger, Bernard; Cloarec, Olivier; Heinzmann, Silke S; Charton, Florence; Krause, Lutz; Levin, Nadine S; Duncker, Swantje; Mercenier, Annick; Holmes, Elaine; Bailey, Mick; Nicholson, Jeremy K

    2016-01-01

    The postnatal environment, including factors such as weaning and acquisition of the gut microbiota, has been causally linked to the development of later immunological diseases such as allergy and autoimmunity, and has also been associated with a predisposition to metabolic disorders. We show that the very early-life environment influences the development of both the gut microbiota and host metabolic phenotype in a porcine model of human infants. Farm piglets were nursed by their mothers for 1 day, before removal to highly controlled, individual isolators where they received formula milk until weaning at 21 days. The experiment was repeated, to create two batches, which differed only in minor environmental fluctuations during the first day. At day 1 after birth, metabolic profiling of serum by (1)H nuclear magnetic resonance spectroscopy demonstrated significant, systemic, inter-batch variation which persisted until weaning. However, the urinary metabolic profiles demonstrated that significant inter-batch effects on 3-hydroxyisovalerate, trimethylamine-N-oxide and mannitol persisted beyond weaning to at least 35 days. Batch effects were linked to significant differences in the composition of colonic microbiota at 35 days, determined by 16 S pyrosequencing. Different weaning diets modulated both the microbiota and metabolic phenotype independently of the persistent batch effects. We demonstrate that the environment during the first day of life influences development of the microbiota and metabolic phenotype and thus should be taken into account when interrogating experimental outcomes. In addition, we suggest that intervention at this early time could provide 'metabolic rescue' for at-risk infants who have undergone aberrant patterns of initial intestinal colonisation.

  15. How Useful Is The Genuine Savings Rate As A Macroeconomic Sustainability Indicator For Countries And Regions? Australia And Queensland Compared

    OpenAIRE

    Assoc Prof Richard Brown; John Asafu-Adjaye; Draca, M; A. Straton

    2003-01-01

    This paper demonstrates how macroeconomic indicators of sustainable development can be applied to the Queensland economy. We derive a Genuine Savings Rate (GSR) for Queensland for the period 1989 to 1999, which is then compared with the World Bank estimate of Australia's GSR for the same period. Specifically, we examine how well a single "headline" indicator based on the World Bank's GSR performs as a measure of overall sustainability. In doing so, we review criticisms of the GSR and compare ...

  16. Metabolic Rate M[superscript 0.75] in Human Beings

    Science.gov (United States)

    Agrawal. D. C.

    2014-01-01

    Human beings consume energy every day. Even at rest, energy is still needed for the working of the internal organs. This is achieved by the metabolism of consumed food in the presence of inhaled oxygen. During the resting state this is called the maintenance rate, and follows the mouse-to-elephant formula, P[subscript met] = 70M[superscript 0.75]…

  17. Metabolic rate of the red panda, Ailurus fulgens, a dietary bamboo specialist

    OpenAIRE

    Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

    2017-01-01

    The red panda (Ailurus fulgens) has a similar diet, primarily bamboo, and shares the same habitat as the giant panda, Ailuropoda melanoleuca. There are considerable efforts underway to understand the ecology of the red panda and to increase its populations in natural reserves. Yet it is difficult to design an effective strategy for red panda reintroduction if we do not understand its basic biology. Here we report the resting metabolic rate of the red panda and find that it is higher than prev...

  18. Is There a Chronic Elevation in Organ-Tissue Sleeping Metabolic Rate in Very Fit Runners?

    Directory of Open Access Journals (Sweden)

    Taishi Midorikawa

    2016-04-01

    Full Text Available It is unclear whether the resting metabolic rate of individual organ-tissue in adults with high aerobic fitness is higher than that in untrained adults; in fact, this topic has been debated for years using a two-component model. To address this issue, in the present study, we examined the relationship between the measured sleeping energy expenditure (EE by using an indirect human calorimeter (IHC and the calculated resting EE (REE from organ-tissue mass using magnetic resonance imaging, along with the assumed metabolic rate constants in healthy adults. Seventeen healthy male long-distance runners were recruited and grouped according to the median \\(\\dot{\\text{V}}\\O2peak: very fit group (>60 mL/min/kg; n = 8 and fit group (<60 mL/min/kg; n = 9. Participants performed a graded exercise test for determining \\(\\dot{\\text{V}}\\O2peak; X-ray absorptiometry and magnetic resonance imaging were used to determine organ-tissue mass, and IHC was used to determine sleeping EE. The calculated REE was estimated as the sum of individual organ-tissue masses multiplied by their metabolic rate constants. No significant difference was observed in the measured sleeping EE, calculated REE, and their difference, as well as in the slopes and intercepts of the two regression lines between the groups. Moreover, no significant correlation between \\(\\dot{\\text{V}}\\O2peak and the difference in measured sleeping EE and calculated REE was observed for all subjects. Thus, aerobic endurance training does not result in a chronic elevation in the organ-tissue metabolic rate in cases with \\(\\dot{\\text{V}}\\O2peak of approximately 60 mL/min/kg.

  19. Is There a Chronic Elevation in Organ-Tissue Sleeping Metabolic Rate in Very Fit Runners?

    Science.gov (United States)

    Midorikawa, Taishi; Tanaka, Shigeho; Ando, Takafumi; Tanaka, Chiaki; Masayuki, Konishi; Ohta, Megumi; Torii, Suguru; Sakamoto, Shizuo

    2016-01-01

    It is unclear whether the resting metabolic rate of individual organ-tissue in adults with high aerobic fitness is higher than that in untrained adults; in fact, this topic has been debated for years using a two-component model. To address this issue, in the present study, we examined the relationship between the measured sleeping energy expenditure (EE) by using an indirect human calorimeter (IHC) and the calculated resting EE (REE) from organ-tissue mass using magnetic resonance imaging, along with the assumed metabolic rate constants in healthy adults. Seventeen healthy male long-distance runners were recruited and grouped according to the median V·O2peak: very fit group (>60 mL/min/kg; n = 8) and fit group (<60 mL/min/kg; n = 9). Participants performed a graded exercise test for determining V·O2peak; X-ray absorptiometry and magnetic resonance imaging were used to determine organ-tissue mass, and IHC was used to determine sleeping EE. The calculated REE was estimated as the sum of individual organ-tissue masses multiplied by their metabolic rate constants. No significant difference was observed in the measured sleeping EE, calculated REE, and their difference, as well as in the slopes and intercepts of the two regression lines between the groups. Moreover, no significant correlation between V·O2peak and the difference in measured sleeping EE and calculated REE was observed for all subjects. Thus, aerobic endurance training does not result in a chronic elevation in the organ-tissue metabolic rate in cases with V·O2peak of approximately 60 mL/min/kg.

  20. Metabolic control analysis of biochemical pathways based on a thermokinetic description of reaction rates

    DEFF Research Database (Denmark)

    Nielsen, Jens Bredal

    1997-01-01

    of the thermokinetic description of reaction rates to include the influence of effecters. Here the reaction rate is written as a linear function of the logarithm of the metabolite concentrations. With this type of rate function it is shown that the approach of Delgado and Liao [Biochem. J. (1992) 282, 919-927] can......Metabolic control analysis is a powerful technique for the evaluation of flux control within biochemical pathways. Its foundation is the elasticity coefficients and the flux control coefficients (FCCs). On the basis of a thermokinetic description of reaction rates it is here shown...... that the elasticity coefficients can be calculated directly from the pool levels of metabolites at steady state. The only requirement is that one thermodynamic parameter be known, namely the reaction affinity at the intercept of the tangent in the inflection point of the curve of reaction rate against reaction...

  1. TT Mutant Homozygote of Is a Key Factor for Increasing Basal Metabolic Rate and Resting Metabolic Rate in Korean Elementary School Children

    Directory of Open Access Journals (Sweden)

    Jung Ran Choi

    2013-12-01

    Full Text Available We investigated the contribution of genetic variations of KLF5 to basal metabolic rate (BMR and resting metabolic rate (RMR and the inhibition of obesity in Korean children. A variation of KLF5 (rs3782933 was genotyped in 62 Korean children. Using multiple linear regression analysis, we developed a model to predict BMR in children. We divided them into several groups; normal versus overweight by body mass index (BMI and low BMR versus high BMR by BMR. There were no differences in the distributions of alleles and genotypes between each group. The genetic variation of KLF5 gene showed a significant correlation with several clinical factors, such as BMR, muscle, low-density lipoprotein cholesterol, and insulin. Children with the TT had significantly higher BMR than those with CC (p = 0.030. The highest muscle was observed in the children with TT compared with CC (p = 0.032. The insulin and C-peptide values were higher in children with TT than those with CC (p= 0.029 vs. p = 0.004, respectively. In linear regression analysis, BMI and muscle mass were correlated with BMR, whereas insulin and C-peptide were not associated with BMR. In the high-BMR group, we observed that higher muscle, fat mass, and C-peptide affect the increase of BMR in children with TT (p < 0.001, p < 0.001, and p = 0.018, respectively, while Rohrer's index could explain the usual decrease in BMR (adjust r2 = 1.000, p < 0.001, respectively. We identified a novel association between TT of KLF5 rs3782933 and BMR in Korean children. We could make better use of the variation within KLF5 in a future clinical intervention study of obesity.

  2. Resting cardiac energy metabolism is inversely associated with heart rate in healthy young adult men.

    Science.gov (United States)

    Fragasso, Gabriele; De Cobelli, Francesco; Spoladore, Roberto; Esposito, Antonio; Salerno, Anna; Calori, Giliola; Montanaro, Claudia; Maranta, Francesco; Lattuada, Guido; Margonato, Alberto; Del Maschio, Alessandro; Perseghin, Gianluca

    2011-07-01

    31-Phosphorus-magnetic resonance spectroscopy may provide pathophysiological insights into the high-energy phosphate metabolism of the myocardium as measured by phosphocreatine to adenosine triphosphate (PCr/ATP) ratio. Aim of the present study was to determine in vivo the relation between cardiac PCr/ATP ratio and heart rate in normal male subjects. One hundred twelve apparently healthy, young male individuals (age 34 ± 10 years) were prospectively evaluated. They underwent cardiac cine magnetic resonance imaging to assess left ventricular (LV) function and morphology and 3D-ISIS (31)P-magnetic resonance spectroscopy of the LV to assess the PCr/ATP ratio (a recognized in vivo marker of myocardial energy metabolism). Data were analyzed after segregation by tertiles of the resting PCr/ATP ratio. A significant inverse association between PCr/ATP ratios and resting heart rate was observed (Spearman ρ: r=-0.37; P heart rate was found to be independently related to PCr/ATP. The present study shows that resting heart rate is proportionally lower across tertiles of increasing PCr/ATP ratio of the LV in apparently healthy young male individuals, supporting the hypothesis that heart rate is a major determinant of cardiac energy stores. These findings may explain the prognostic role of heart rate in the general population as evidenced by previous large epidemiological studies. Copyright © 2011 Mosby, Inc. All rights reserved.

  3. Thermal optimum for pikeperch (Sander lucioperca) and the use of ventilation frequency as a predictor of metabolic rate

    DEFF Research Database (Denmark)

    Frisk, Michael; Skov, Peter Vilhelm; Steffensen, John Fleng

    2012-01-01

    Pikeperch is of increasing interest to the aquaculture industry, as a novel high value species. To our knowledge there is currently no information available on the metabolic rates of adult pikeperch. The present study determined the standard and maximum metabolic rates and ventilation frequency...... at six temperatures, ranging from 13 to 28 °C, in order to identify the temperature where pikeperch has the largest metabolic scope (MS). Between 13 and 25 °C, standard metabolic rates (SMR) increased as expected with a Q10=1.8 in response to increasing temperatures, while maximum metabolic rate (MMR...... consumption rate (M_ O2), during normoxia and progressive hypoxia. A strong correlation was found between fV and M_ O2 across all temperatures, and fV could predict M_ O2 with a high degree of accuracy in normoxia...

  4. Muscle-tendon mechanics explain unexpected effects of exoskeleton assistance on metabolic rate during walking.

    Science.gov (United States)

    Jackson, Rachel W; Dembia, Christopher L; Delp, Scott L; Collins, Steven H

    2017-06-01

    The goal of this study was to gain insight into how ankle exoskeletons affect the behavior of the plantarflexor muscles during walking. Using data from previous experiments, we performed electromyography-driven simulations of musculoskeletal dynamics to explore how changes in exoskeleton assistance affected plantarflexor muscle-tendon mechanics, particularly for the soleus. We used a model of muscle energy consumption to estimate individual muscle metabolic rate. As average exoskeleton torque was increased, while no net exoskeleton work was provided, a reduction in tendon recoil led to an increase in positive mechanical work performed by the soleus muscle fibers. As net exoskeleton work was increased, both soleus muscle fiber force and positive mechanical work decreased. Trends in the sum of the metabolic rates of the simulated muscles correlated well with trends in experimentally observed whole-body metabolic rate (R2=0.9), providing confidence in our model estimates. Our simulation results suggest that different exoskeleton behaviors can alter the functioning of the muscles and tendons acting at the assisted joint. Furthermore, our results support the idea that the series tendon helps reduce positive work done by the muscle fibers by storing and returning energy elastically. We expect the results from this study to promote the use of electromyography-driven simulations to gain insight into the operation of muscle-tendon units and to guide the design and control of assistive devices. © 2017. Published by The Company of Biologists Ltd.

  5. Water hyacinth: a possible alternative rate retarding natural polymer used in sustained release tablet design.

    Science.gov (United States)

    Khatun, Sabera; Sutradhar, Kumar B

    2014-01-01

    In recent years natural polymers have been widely used because of their effectiveness and availability over synthetic polymers. In this present investigation matrix tablets of Metformin hydrochloride were formulated using Water hyacinth powder and its rate retardant activity was studied. Tablets were prepared using wet granulation method with 8% starch as granulating agent and 5, 10, 15, 20, 25 and 30% of Water hyacinth powder to the drug. In preformulation study, angle of repose, Carr's Index and Hausner ratio were calculated. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) studies were performed and no interactions were found between drug and excipients. Weight variation, friability, hardness, thickness, diameter, and in vitro release study were performed with the prepared matrix tablets. Dissolution studies were conducted using USP type II apparatus at a speed of 100 rpm at 37°C ± 0.5 temperature for 8 h. Though all the formulations comply with both BP and USP requirements, formulation F-1 (5% of Water hyacinth) was the best fitted formula. The drug release patterns were explained in different kinetic models such as Zero order, First order, Higuchi, Hixson Crowell, and Korsmeyer-Peppas equations. The current investigation implies that Water hyacinth has the potential to be used as a rate-retarding agent in sustained release drug formulations.

  6. WATER HYACINTH: A POSSIBLE ALTERNATIVE RATE RETARDING NATURAL POLYMER USED IN SUSTAINED RELEASE TABLET DESIGN

    Directory of Open Access Journals (Sweden)

    Sabera eKhatun

    2014-06-01

    Full Text Available In recent years natural polymers have been widely used, because of their effectiveness and availability over synthetic polymers. In this present investigation matrix tablets of Metformin hydrochloride were formulated using Water hyacinth powder and its rate retardant activity was studied. Tablets were prepared using wet granulation method with 8% starch as granulating agent and 5%, 10%, 15%, 20%, 25% and 30% of Water hyacinth powder to the drug. In preformulation study, angle of repose, Carr’s Index and Hausner ratio were calculated. Fourier Transform Infrared Spectroscopy (FTIR, Differential Scanning Calorimetry (DSC and Scanning Electron Microscopy (SEM studies were performed and no interactions were found between drug and excipients. Weight variation, friability, hardness, thickness, diameter, and in vitro release study were performed with the prepared matrix tablets. Dissolution studies were conducted using USP type II apparatus at a speed of 100 rpm at 37oC ± 0.5 temperature, for 8 hours. All the formulations comply with both BP and USP requirements, but among all the formulations F-1 (5% of Water hyacinth was the best fitted formula. The drug release patterns were explained in different kinetic models such as Zero order, First order, Higuchi, Hixson Crowell and Korsmeyer-Peppas equations. The current investigation implies that Water hyacinth has the potential to be used as a rate-retarding agent in sustained release drug formulations.

  7. Autonomic control of heart rate by metabolically sensitive skeletal muscle afferents in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Seifert, Thomas; Hartwich, Doreen

    2010-01-01

    Isolated activation of metabolically sensitive skeletal muscle afferents (muscle metaboreflex) using post-exercise ischaemia (PEI) following handgrip partially maintains exercise-induced increases in arterial blood pressure (BP) and muscle sympathetic nerve activity (SNA), while heart rate (HR...... of cardiac parasympathetic reactivation on heart rate....... moderate (PEI-M) and high (PEI-H) intensity isometric handgrip performed at 25% and 40% maximum voluntary contraction, under control (no drug), parasympathetic blockade (glycopyrrolate) and beta-adrenergic blockade (metoprolol or propranalol) conditions, while beat-to-beat HR and BP were continuously...

  8. Dedicated Industrial Oilseed Crops as Metabolic Engineering Platforms for Sustainable Industrial Feedstock Production

    NARCIS (Netherlands)

    Zhu, Li Hua; Krens, Frans; Smith, Mark A.; Li, Xueyuan; Qi, Weicong; Loo, Van Eibertus N.; Iven, Tim; Feussner, Ivo; Nazarenus, Tara J.; Huai, Dongxin; Taylor, David C.; Zhou, Xue Rong; Green, Allan G.; Shockey, Jay; Klasson, Thomas K.; Mullen, Robert T.; Huang, Bangquan; Dyer, John M.; Cahoon, Edgar B.

    2016-01-01

    Feedstocks for industrial applications ranging from polymers to lubricants are largely derived from petroleum, a non-renewable resource. Vegetable oils with fatty acid structures and storage forms tailored for specific industrial uses offer renewable and potentially sustainable sources of

  9. Quorum Sensing Coordinates Cooperative Expression of Pyruvate Metabolism Genes To Maintain a Sustainable Environment for Population Stability.

    Science.gov (United States)

    Hawver, Lisa A; Giulietti, Jennifer M; Baleja, James D; Ng, Wai-Leung

    2016-12-06

    Quorum sensing (QS) is a microbial cell-cell communication system that regulates gene expression in response to population density to coordinate collective behaviors. Yet, the role of QS in resolving the stresses caused by the accumulation of toxic metabolic by-products at high cell density is not well defined. In response to cell density, QS could be involved in reprogramming of the metabolic network to maintain population stability. Using unbiased metabolomics, we discovered that Vibrio cholerae mutants genetically locked in a low cell density (LCD) QS state are unable to alter the pyruvate flux to convert fermentable carbon sources into neutral acetoin and 2,3-butanediol molecules to offset organic acid production. As a consequence, LCD-locked QS mutants rapidly lose viability when grown with fermentable carbon sources. This key metabolic switch relies on the QS-regulated small RNAs Qrr1-4 but is independent of known QS regulators AphA and HapR. Qrr1-4 dictate pyruvate flux by translational repression of the enzyme AlsS, which carries out the first step in acetoin and 2,3-butanediol biosynthesis. Consistent with the idea that QS facilitates the expression of a common trait in the population, AlsS needs to be expressed cooperatively in a group of cells. Heterogeneous populations with high percentages of cells not expressing AlsS are unstable. All of the cells, regardless of their respective QS states, succumb to stresses caused by toxic by-product accumulation. Our results indicate that the ability of the bacteria to cooperatively control metabolic flux through QS is critical in maintaining a sustainable environment and overall population stability. Our work reveals a novel role for Vibrio cholerae quorum sensing (QS) in relieving the stresses caused by toxic metabolite accumulation when the population becomes crowded through metabolic reprogramming. QS enables V. cholerae switching from a low cell density energy-generating metabolism that is beneficial to

  10. Metabolic rate control during extravehicular activity simulations and measurement techniques during actual EVAS

    Science.gov (United States)

    Horrigan, D. J.

    1975-01-01

    A description of the methods used to control and measure metabolic rate during ground simulations is given. Work levels attained at the Space Environment Simulation Laboratory are presented. The techniques and data acquired during ground simulations are described and compared with inflight procedures. Data from both the Skylab and Apollo Program were utilized and emphasis is given to the methodology, both in simulation and during flight. The basic techniques of work rate assessment are described. They include oxygen consumption, which was useful for averages over long time periods, heart rate correlations based on laboratory calibrations, and liquid cooling garment temperature changes. The relative accuracy of these methods as well as the methods of real-time monitoring at the Mission Control Center are discussed. The advantages and disadvantages of each of the metabolic measurement techniques are discussed. Particular emphasis is given to the problem of utilizing oxygen decrement for short time periods and heart rate at low work levels. A summary is given of the effectiveness of work rate control and measurements; and current plans for future EVA monitoring are discussed.

  11. Food composition influences metabolism, heart rate and organ growth during digestion in Python regius.

    Science.gov (United States)

    Henriksen, Poul Secher; Enok, Sanne; Overgaard, Johannes; Wang, Tobias

    2015-05-01

    Digestion in pythons is associated with a large increase in oxygen consumption (SDA), increased cardiac output and growth in visceral organs assisting in digestion. The processes leading to the large postprandial rise in metabolism in snakes is subject to opposing views. Gastric work, protein synthesis and organ growth have each been speculated to be major contributors to the SDA. To investigate the role of food composition on SDA, heart rate (HR) and organ growth, 48 ball pythons (Python regius) were fed meals of either fat, glucose, protein or protein combined with carbonate. Our study shows that protein, in the absence or presence of carbonate causes a large SDA response, while glucose caused a significantly smaller SDA response and digestion of fat failed to affect metabolism. Addition of carbonate to the diet to stimulate gastric acid secretion did not increase the SDA response. These results support protein synthesis as a major contributor to the SDA response and show that increased gastric acid secretion occurs at a low metabolic cost. The increase in metabolism was supported by tachycardia caused by altered autonomic regulation as well as an increased non-adrenergic, non-cholinergic (NANC) tone in response to all diets, except for the lipid meal. Organ growth only occurred in the small intestine and liver in snakes fed on a high protein diet. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Repeatability of standard metabolic rate (SMR) in a small fish, the spined loach (Cobitis taenia).

    Science.gov (United States)

    Maciak, Sebastian; Konarzewski, Marek

    2010-10-01

    Significant repeatability of a trait of interest is an essential assumption for undertaking studies of phenotypic variability. It is especially important in studies on highly variable traits, such as metabolic rates. Recent publications suggest that resting/basal metabolic rate of homeotherms is repeatable across wide range of species. In contrast, studies on the consistency of standard metabolic rate (SMR) in ectotherms, particularly fish, are scarce. Here we present a comprehensive analysis of several important technical aspects of body mass-corrected SMR measurements and its repeatability in a small (average weight approximately 3g) fish, the spined loach (Cobitis taenia). First we demonstrated that release of oxygen from the walls of metabolic chambers exposed to hypoxic conditions did not confound SMR measurements. Next, using principle of propagation of measurement uncertainties we demonstrated that in aquatic systems, measurement error is significantly higher in open than closed respirometry setups. The measurement error for SMR of a small fish determined in a closed aquatic system is comparable to that obtainable using top-notch open-flow systems used for air-breathing terrestrial animals. Using a closed respirometer we demonstrated that body mass-corrected SMR in spined loaches was repeatable under both normoxia and hypoxia over a 5-month period (Pearson correlation r=0.68 and r=0.73, respectively) as well as across both conditions (intraclass correlation coefficient tau=0.30). In these analyses we accounted for possible effect of oxygen consumption of the oxygen electrode on repeatability of SMR. Significant SMR consistency was accompanied by significant repeatability of body mass (intraclass correlation coefficient tau=0.86). To our knowledge, this is the first study showing long-term repeatability of body mass and SMR in a small fish, and is consistent with the existence of heritable variation of these two traits. 2010 Elsevier Inc. All rights reserved.

  13. Military personnel sustaining Lisfranc injuries have high rates of disability separation.

    Science.gov (United States)

    Balazs, George C; Hanley, M G; Pavey, G J; Rue, J-Ph

    2017-06-01

    Lisfranc injuries are relatively uncommon midfoot injuries disproportionately affecting young, active males. Previous studies in civilian populations have reported relatively good results with operative treatment. However, treatment results have not been specifically examined in military personnel, who may have higher physical demands than the general population. The purpose of this study was to examine rates of return to military duty following surgical treatment of isolated Lisfranc injuries. Surgical records and radiographic images from all active duty US military personnel treated for an isolated Lisfranc injury between January 2005 and July 2014 were examined. Demographic information, injury data, surgical details and subsequent return to duty information were recorded. The primary outcome was ability to return to unrestricted military duty following treatment. The secondary outcome was secondary conversion to a midfoot arthrodesis following initial open reduction internal fixation. Twenty-one patients meeting inclusion criteria were identified. Median patient age was 23 years, and mean follow-up was 43 months. Within this cohort, 14 patients were able to return to military service, while seven required a disability separation from the armed forces. Of the 18 patients who underwent initial fixation, eight were subsequently revised to midfoot arthrodesis for persistent pain. Military personnel sustaining Lisfranc injuries have high rates of persistent pain and disability, even after optimal initial surgical treatment. Military surgeons should counsel patients on the career-threatening nature of this condition and high rates of secondary procedures. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  14. Intraspecific variation in flight metabolic rate in the bumblebee Bombus impatiens: repeatability and functional determinants in workers and drones.

    Science.gov (United States)

    Darveau, Charles-A; Billardon, Fannie; Bélanger, Kasandra

    2014-02-15

    The evolution of flight energetics requires that phenotypes be variable, repeatable and heritable. We studied intraspecific variation in flight energetics in order to assess the repeatability of flight metabolic rate and wingbeat frequency, as well as the functional basis of phenotypic variation in workers and drones of the bumblebee species Bombus impatiens. We showed that flight metabolic rate and wingbeat frequency were highly repeatable in workers, even when controlling for body mass variation using residual analysis. We did not detect significant repeatability in drones, but a smaller range of variation might have prevented us from finding significant values in our sample. Based on our results and previous findings, we associated the high repeatability of flight phenotypes in workers to the functional links between body mass, thorax mass, wing size, wingbeat frequency and metabolic rate. Moreover, differences between workers and drones were as predicted from these functional associations, where drones had larger wings for their size, lower wingbeat frequency and lower flight metabolic rate. We also investigated thoracic muscle metabolic phenotypes by measuring the activity of carbohydrate metabolism enzymes, and we found positive correlations between mass-independent metabolic rate and the activity of all enzymes measured, but in workers only. When comparing workers and drones that differ in flight metabolic rate, only the activity of the enzymes hexokinase and trehalase showed the predicted differences. Overall, our study indicates that there should be correlated evolution among physiological phenotypes at multiple levels of organization and morphological traits associated with flight.

  15. Measuring maximum and standard metabolic rates using intermittent-flow respirometry: a student laboratory investigation of aerobic metabolic scope and environmental hypoxia in aquatic breathers.

    Science.gov (United States)

    Rosewarne, P J; Wilson, J M; Svendsen, J C

    2016-01-01

    Metabolic rate is one of the most widely measured physiological traits in animals and may be influenced by both endogenous (e.g. body mass) and exogenous factors (e.g. oxygen availability and temperature). Standard metabolic rate (SMR) and maximum metabolic rate (MMR) are two fundamental physiological variables providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available between these two variables constitutes the aerobic metabolic scope (AMS). A laboratory exercise aimed at an undergraduate level physiology class, which details the appropriate data acquisition methods and calculations to measure oxygen consumption rates in rainbow trout Oncorhynchus mykiss, is presented here. Specifically, the teaching exercise employs intermittent flow respirometry to measure SMR and MMR, derives AMS from the measurements and demonstrates how AMS is affected by environmental oxygen. Students' results typically reveal a decline in AMS in response to environmental hypoxia. The same techniques can be applied to investigate the influence of other key factors on metabolic rate (e.g. temperature and body mass). Discussion of the results develops students' understanding of the mechanisms underlying these fundamental physiological traits and the influence of exogenous factors. More generally, the teaching exercise outlines essential laboratory concepts in addition to metabolic rate calculations, data acquisition and unit conversions that enhance competency in quantitative analysis and reasoning. Finally, the described procedures are generally applicable to other fish species or aquatic breathers such as crustaceans (e.g. crayfish) and provide an alternative to using higher (or more derived) animals to investigate questions related to metabolic physiology. © 2016 The Fisheries Society of the British Isles.

  16. Diets supplemented with seaweed affect metabolic rate, innate immune, and antioxidant responses, but not individual growth rate in European seabass (Dicentrarchus labrax)

    DEFF Research Database (Denmark)

    Peixoto, Maria J.; Svendsen, Jon Christian; Malte, Hans

    2016-01-01

    in triplicate groups of 20 fish (initial body weight 25.5 ± 4.1 g). Final results showed similar growth rates and digestive activities between diets. Maximum and standard metabolic rates and aerobic metabolic scope revealed comparable results for the three diets. In contrast, fish fed with GR7.5 exhibited......This study investigated the effects of seaweed dietary supplementation on measures of fish performance including aerobic metabolism, digestive enzymes activity, innate immune status, oxidative damage, and growth rate using European seabass (Dicentrarchus labrax). Fish were fed for 49 days...... elevated routine metabolic rate (190.7 mg O2 kg−1 h−1). Fish fed with the GR7.5 and Mix diets had lower alternative complement pathway (ACH50) (62.5 and 63 units mL−1 respectively) than CTRL (84 units mL−1) GR7.5 increased lipid peroxidation and cholinesterase levels, as well as glutathione s...

  17. Climate and foraging mode explain interspecific variation in snake metabolic rates.

    Science.gov (United States)

    Dupoué, Andréaz; Brischoux, François; Lourdais, Olivier

    2017-11-29

    The energy cost of self-maintenance is a critical facet of life-history strategies. Clarifying the determinant of interspecific variation in metabolic rate (MR) at rest is important to understand and predict ecological patterns such as species distributions or responses to climatic changes. We examined variation of MR in snakes, a group characterized by a remarkable diversity of activity rates and a wide distribution. We collated previously published MR data (n = 491 observations) measured in 90 snake species at different trial temperatures. We tested for the effects of metabolic state (standard MR (SMR) versus resting MR (RMR)), foraging mode (active versus ambush foragers) and climate (temperature and precipitation) while accounting for non-independence owing to phylogeny, body mass and thermal dependence. We found that RMR was 40% higher than SMR, and that active foragers have higher MR than species that ambush their prey. We found that MR was higher in cold environments, supporting the metabolic cold adaptation hypothesis. We also found an additive and positive effect of precipitation on MR suggesting that lower MR in arid environments may decrease dehydration and energetic costs. Altogether, our findings underline the complex influences of climate and foraging mode on MR and emphasize the relevance of these facets to understand the physiological impact of climate change. © 2017 The Author(s).

  18. Standard metabolic rate of the bed bug, Cimex lectularius: effects of temperature, mass, and life stage.

    Science.gov (United States)

    Devries, Zachary C; Kells, Stephen A; Appel, Arthur G

    2013-11-01

    Metabolic rates provide important information about the biology of organisms. For ectothermic species such as insects, factors such as temperature and mass heavily influence metabolism, but these effects differ considerably between species. In this study we examined the standard metabolic rate of the bed bug, Cimex lectularius L. We used closed system respirometry and measured both O2 consumption and CO2 production across a range of temperatures (10, 20, 25, 30, 35°C) and life stages, while also accounting for activity. Temperature had a stronger effect on the mass specific .VO2 (mlg(-1)h(-1)) of mated males (Q10=3.29), mated females (Q10=3.19), unmated males (Q10=3.09), and nymphs that hatched (first instars, Q10=3.05) than on unmated females (Q10=2.77) and nymphs that molted (second through fifth instars, Q10=2.78). First instars had significantly lower respiratory quotients (RQ) than all other life stages. RQ of all stages was not affected by temperature. .VO2 (mlh(-1)) scaled more with mass than values previously reported for other arthropods or that would be predicted by the 3/4-power law. The results are used to understand the biology and ecology of the bed bug. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Sustainability assessment of succinic acid production technologies from biomass using metabolic engineering

    OpenAIRE

    Morales M.; Ataman M.; Badr S.; Linster S.; Kourlimpinis I.; Papadokonstantakis S.; Hatzimanikatis V.; Hungerbühlera K.

    2016-01-01

    Over the past few years bio succinic acid from renewable resources has gained increasing attention as a potential bio derived platform chemical for the detergent/surfactant ion chelator food and pharmaceutical markets. Until now much research was undertaken to lower the production costs of bio succinic acid however a multicriteria sustainability evaluation of established and upcoming production processes from a technical perspective is still lacking in the scientific literature. In this study...

  20. Spatial variation in the relationship between performance and metabolic rate in wild juvenile Atlantic salmon.

    Science.gov (United States)

    Robertsen, Grethe; Armstrong, John D; Nislow, Keith H; Herfindal, Ivar; McKelvey, Simon; Einum, Sigurd

    2014-07-01

    Maintenance of metabolic rate (MR, the energy cost of self-maintenance) is linked to behavioural traits and fitness and varies substantially within populations. Despite having received much attention, the causes and consequences of this variation remain obscure. Theoretically, such within-population variation in fitness-related traits can be maintained by environmental heterogeneity in selection patterns, but for MR, this has rarely been tested in nature. Here, we experimentally test whether the relationship between MR and performance can vary spatially by assessing survival, growth rate and movement of Atlantic salmon (Salmo salar L.) juveniles from 10 family groups differing in MR (measured as egg metabolism) that were stocked in parallel across 10 tributaries of a single watershed. The relationship between MR and relative survival and growth rate varied significantly among tributaries. Specifically, the effect of MR ranged from negative to positive for relative survival, whereas it was negative for growth rate. The association between MR and movement was positive and did not vary significantly among tributaries. These results are consistent with a fitness cost of traits associated with behavioural dominance that varies across relatively small spatial scales (within a single watershed). More generally, our results support the hypothesis that spatial heterogeneity in environmental conditions contributes to maintain within-population variation in fitness-related traits, such as MR. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  1. Prolonged saltatory fetal heart rate pattern leading to newborn metabolic acidosis.

    Science.gov (United States)

    Nunes, I; Ayres-de-Campos, D; Kwee, A; Rosén, K G

    2014-01-01

    The saltatory pattern, characterized by wide and rapid oscillations of the fetal heart rate (FHR), remains a controversial entity. The authors sought to evaluate whether it could be associated with an adverse fetal outcome. The authors report a case series of four saltatory patterns occurring in the last 30 minutes before birth in association with cord artery metabolic acidosis, obtained from three large databases of internally acquired FHR tracings. The distinctive characteristics of this pattern were evaluated with the aid of a computer system. All cases were recorded in uneventful pregnancies, with normal birthweight singletons, born vaginally at term. The saltatory pattern lasted between 23 and 44 minutes, exhibited a mean oscillatory amplitude of 45.9 to 80.0 beats per minute (bpm) and a frequency between four and eight cycles per minute. A saltatory pattern exceeding 20 minutes can be associated with the occurrence of fetal metabolic acidosis.

  2. Obesity-associated metabolic changes influence resting and peak heart rate in women and men.

    Science.gov (United States)

    Strandheim, Astrid; Halland, Hilde; Saeed, Sahrai; Cramariuc, Dana; Hetland, Trude; Lønnebakken, Mai Tone; Gerdts, Eva

    2015-01-01

    To study the relationship between obesity and heart rate (HR) in women and men. We studied 241 overweight and obese subjects without known heart disease. All subjects underwent ergospirometry during maximal exercise testing on treadmill and recording of body composition, electrocardiogram and clinic and ambulatory blood pressure. Women (n = 132) were slightly older and had higher fat mass, but lower weight, blood pressure and prevalence of metabolic syndrome (MetS) than men (n = 109) (all p obesity and hypertension did not differ. A significant interaction between sex and HR was demonstrated (p obesity were the main covariates in women in multivariate analyses (all p obesity and obesity-associated metabolic changes influenced both resting and peak exercise HR.

  3. Metabolic processes sustaining the reviviscence of lichen Xanthoria elegans (Link) in high mountain environments.

    OpenAIRE

    Aubert, Serge; Juge, Christine; Boisson, Anne-Marie; Gout, Elisabeth; Bligny, Richard

    2007-01-01

    International audience; To survive in high mountain environments lichens must adapt themselves to alternating periods of desiccation and hydration. Respiration and photosynthesis of the foliaceous lichen, Xanthoria elegans, in the dehydrated state were below the threshold of CO2-detection by infrared gas analysis. Following hydration, respiration totally recovered within seconds and photosynthesis within minutes. In order to identify metabolic processes that may contribute to the quick and ef...

  4. Sustainable mechanical biological treatment of solid waste in urbanized areas with low recycling rates.

    Science.gov (United States)

    Trulli, Ettore; Ferronato, Navarro; Torretta, Vincenzo; Piscitelli, Massimiliano; Masi, Salvatore; Mancini, Ignazio

    2018-01-01

    Landfill is still the main technological facility used to treat and dispose municipal solid waste (MSW) worldwide. In developing countries, final dumping is applied without environmental monitoring and soil protection since solid waste is mostly sent to open dump sites while, in Europe, landfilling is considered as the last option since reverse logistic approaches or energy recovery are generally encouraged. However, many regions within the European Union continue to dispose of MSW to landfill, since modern facilities have not been introduced owing to unreliable regulations or financial sustainability. In this paper, final disposal activities and pre-treatment operations in an area in southern Italy are discussed, where final disposal is still the main option for treating MSW and the recycling rate is still low. Mechanical biological treatment (MBT) facilities are examined in order to evaluate the organic stabilization practices applied for MSW and the efficiencies in refuse derived fuel production, organic waste stabilization and mass reduction. Implementing MBT before landfilling the environmental impact and waste mass are reduced, up to 30%, since organic fractions are stabilized resulting an oxygen uptake rate less than 1600 mgO2 h-1 kg-1VS, and inorganic materials are exploited. Based on experimental data, this work examines MBT application in contexts where recycling and recovery activities have not been fully developed. The evidence of this study led to state that the introduction of MBT facilities is recommended for developing regions with high putrescible waste production in order to decrease environmental pollution and enhance human healthy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Physiological effects of bioceramic material: harvard step, resting metabolic rate and treadmill running assessments.

    Science.gov (United States)

    Leung, Ting-Kai; Kuo, Chia-Hua; Lee, Chi-Ming; Kan, Nai-Wen; Hou, Chien-Wen

    2013-12-31

    Previous biomolecular and animal studies have shown that a room-temperature far-infrared-rayemitting ceramic material (bioceramic) demonstrates physical-biological effects, including the normalization of psychologically induced stress-conditioned elevated heart rate in animals. In this clinical study, the Harvard step test, the resting metabolic rate (RMR) assessment and the treadmill running test were conducted to evaluate possible physiological effects of the bioceramic material in human patients. The analysis of heart rate variability (HRV) during the Harvard step test indicated that the bioceramic material significantly increased the high-frequency (HF) power spectrum. In addition, the results of RMR analysis suggest that the bioceramic material reduced oxygen consumption (VO2). Our results demonstrate that the bioceramic material has the tendency to stimulate parasympathetic responses, which may reduce resting energy expenditure and improve cardiorespiratory recovery following exercise.

  6. Rates of performance loss and neuromuscular activity in men and women during cycling: evidence for a common metabolic basis of muscle fatigue

    Science.gov (United States)

    Hunter, Sandra K.; Bundle, Matthew W.

    2017-01-01

    The durations that muscular force and power outputs can be sustained until failure fall predictably on an exponential decline between an individual’s 3-s burst maximum to the maximum performance they can sustain aerobically. The exponential time constants describing these rates of performance loss are similar across individuals, suggesting that a common metabolically based mechanism governs muscle fatigue; however, these conclusions come from studies mainly on men. To test whether the same physiological understanding can be applied to women, we compared the performance-duration relationships and neuromuscular activity between seven men [23.3 ± 1.9 (SD) yr] and seven women (21.7 ± 1.8 yr) from multiple exhaustive bouts of cycle ergometry. Each subject performed trials to obtain the peak 3-s power output (Pmax), the mechanical power at the aerobic maximum (Paer), and 11–14 constant-load bouts eliciting failure between 3 and 300 s. Collectively, men and women performed 180 exhaustive bouts spanning an ~6-fold range of power outputs (118–1116 W) and an ~35-fold range of trial durations (8–283 s). Men generated 66% greater Pmax (956 ± 109 W vs. 632 ± 74 W) and 68% greater Paer (310 ± 47 W vs. 212 ± 15 W) than women. However, the metabolically based time constants describing the time course of performance loss were similar between men (0.020 ± 0.003/s) and women (0.021 ± 0.003/s). Additionally, the fatigue-induced increases in neuromuscular activity did not differ between the sexes when compared relative to the pedal forces at Paer. These data suggest that muscle fatigue during short-duration dynamic exercise has a common metabolically based mechanism determined by the extent that ATP is resynthesized by anaerobic metabolism. NEW & NOTEWORTHY Although men and women differed considerably in their absolute cycling performances, there was no sex difference in the metabolically based exponential time constant that described the

  7. Effect of nanoparticles of silver and gold on metabolic rate and development of broiler and layer embryos

    DEFF Research Database (Denmark)

    Pineda, L; Sawosz, E; Hotowy, A

    2012-01-01

    -air-circuit respiration unit, and HP was calculated for 10, 13, 16 and 19-day-old embryos. Relative chick and muscle weights were used as a measure of growth rate and development. AgNano but not AuNano increased the rates of O(2) consumption and HP of the layer embryos. The metabolic rate of broiler embryos...... was not affected by either of the treatments, but it was significantly higher compared to the layer embryos. Neither of the nanoparticles promoted nor depressed growth and development of the embryos, irrespective of breed. Although the metabolic rate of AgNano-injected layer embryos was significantly increased......, their BW and muscle weights at hatching were similar to those of the control group, which suggests that the concentration of AgNano used was adequate for increasing the metabolic rate but not enough to affect growth and development. The results show that AgNano could be a potential metabolic modifier...

  8. Is there a relationship between insect metabolic rate and mortality of mealworms Tenebrio molitor L. after insecticide exposure?

    Directory of Open Access Journals (Sweden)

    Justyna MALISZEWSKA

    2016-09-01

    Full Text Available Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication with pyrethroid, oxadiazine, neonicotinoid and organophosphate. Metabolic rate before and after intoxication with insecticides was also determined. The highest CO2 production and mortality rate was observed after mealworms exposition to neonicotinoid insecticide. The results suggest that high CO2 release after intoxication is adequate to the intensity of the non-specific action of the xenobiotic (e.g. hyperactivity of neuromuscular system, rather than the intensity of detoxification processes, and it is correlated with mealworms mortality.

  9. The Pandolf load carriage equation is a poor predictor of metabolic rate while wearing explosive ordnance disposal protective clothing.

    Science.gov (United States)

    Bach, Aaron J E; Costello, Joseph T; Borg, David N; Stewart, Ian B

    2017-03-01

    This investigation aimed to quantify metabolic rate when wearing an explosive ordnance disposal (EOD) ensemble (~33kg) during standing and locomotion; and determine whether the Pandolf load carriage equation accurately predicts metabolic rate when wearing an EOD ensemble during standing and locomotion. Ten males completed 8 trials with metabolic rate measured through indirect calorimetry. Walking in EOD at 2.5, 4.0 and 5.5km·h-1 was significantly (p ensemble by 49% (127W), 65% (213W) and 78% (345W), respectively. Mean bias (95% limits of agreement) between predicted and measured metabolism during standing, 2.5, 4 and 5.5km·h-1 were 47W (19 to 75W); -111W (-172 to -49W); -122W (-189 to -54W) and -158W (-245 to -72W), respectively. The Pandolf equation significantly underestimated measured metabolic rate during locomotion. These findings have practical implications for EOD technicians during training and operation and should be considered when developing maximum workload duration models and work-rest schedules. Practitioner Summary: Using a rigorous methodological design we quantified metabolic rate of wearing EOD clothing during locomotion. For the first time we demonstrated that metabolic rate when wearing this ensemble is greater than that predicted by the Pandolf equation. These original findings have significant implications for EOD training and operation.

  10. Kleptoparasitism and aggressiveness are influenced by standard metabolic rate in eels.

    Science.gov (United States)

    Geffroy, Benjamin; Bolliet, Valérie; Bardonnet, Agnès

    2016-04-01

    Kleptoparasitism refers to either interspecific or intraspecific stealing of food already procured by other species or individuals. Within a given species, individuals might differ in their propensity to use such a tactic, in a similar manner to which they differ in their general level of aggressiveness. Standard metabolic rate is often viewed as a proxy for energy requirements. For this reason, it should directly impact on both kleptoparasitism and aggressiveness when individuals have to share the same food source. In the present study we first assessed the standard metabolic rate (SMR) of 128 juvenile European eels (Anguilla anguilla) by the determination of oxygen consumption. We then tested how the SMR could influence agonistic behavior of individuals competing for food in three distinct trials evenly distributed over three months. We demonstrate that SMR positively correlates with attacks (sum of bite and push events) in all trials. Similarly SMR correlated positively with kleptoparasitism (food theft), but this was significant only for the third trial (month 3). To our knowledge, the present study is the first reporting a link between kleptoparasitism and SMR in a fish species. This has ecological implications owing to the fact that this species is characterized by an environmental sex determination linked to early growth rate. We discuss theses findings in the light of the producer-scrounger foraging game. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Effects of nutritional status on metabolic rate, exercise and recovery in a freshwater fish

    Energy Technology Data Exchange (ETDEWEB)

    Gingerich, Andrew J.; Philipp, D. P.; Suski, C. D.

    2010-11-20

    The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

  12. Flexibility in metabolic rate confers a growth advantage under changing food availability.

    Science.gov (United States)

    Auer, Sonya K; Salin, Karine; Rudolf, Agata M; Anderson, Graeme J; Metcalfe, Neil B

    2015-09-01

    1. Phenotypic flexibility in physiological, morphological and behavioural traits can allow organisms to cope with environmental challenges. Given recent climate change and the degree of habitat modification currently experienced by many organisms, it is therefore critical to quantify the degree of phenotypic variation present within populations, individual capacities to change and what their consequences are for fitness. 2. Flexibility in standard metabolic rate (SMR) may be particularly important since SMR reflects the minimal energetic cost of living and is one of the primary traits underlying organismal performance. SMR can increase or decrease in response to food availability, but the consequences of these changes for growth rates and other fitness components are not well known. 3. We examined individual variation in metabolic flexibility in response to changing food levels and its consequences for somatic growth in juvenile brown trout (Salmo trutta). 4. SMR increased when individuals were switched to a high food ration and decreased when they were switched to a low food regime. These shifts in SMR, in turn, were linked with individual differences in somatic growth; those individuals that increased their SMR more in response to elevated food levels grew fastest, while growth at the low food level was fastest in those individuals that depressed their SMR most. 5. Flexibility in energy metabolism is therefore a key mechanism to maximize growth rates under the challenges imposed by variability in food availability and is likely to be an important determinant of species' resilience in the face of global change. © 2015 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  13. Adipokines may mediate the relationship between resting metabolic rates and bone mineral densities in obese women.

    Science.gov (United States)

    Moradi, S; Mirzaei, K; Abdurahman, A A; Keshavarz, S A

    2017-05-01

    The researchers sought to test the possible link between resting metabolic rate and bone mineral density through four adipokines. Participants with lower resting metabolic rate (RMR) per kilogram demonstrated higher total bone mineral density (BMD), total T-score, and total Z-score. Omentin-1 had a mediatory effect on the relationship between RMR/kg of body weight and bone parameters. The previous results of studies regarding the links between obesity and bone health are controversial. For this reason, the researchers sought to test the possible link between RMR and BMD through the following four adipokines: vaspin, retinol binding protein 4, angiopoietin-like 6 (ANGPL6), and omentin-1. We enrolled 312 obese Iranian women (30 ≤ body mass index BMD, the participants were grouped based on RMR per body weight. Body composition, dietary intake, bone mineral density, and resting metabolic rate were assessed in all participants. Serum adipokine levels were quantified by the enzyme-linked immunosorbent assay (ELISA) method. Low levels of RMR/kg were strongly associated with higher weight, body mass index, fat mass, and visceral fat levels. In fact, participants with an RMR/kg of body weight obese (p BMD, total T-score, and total Z-score. Our results showed that omentin-1 had a mediatory effect on the relationship between RMR per kilogram of body weight and bone parameters (p BMD (p > 0.05). The inhibitory effect of omentin-1 on TNF-alpha seems to be able to reduce the amount of circulating leptin as adipokine, affecting energy expenditure and improving bone loss induced by estrogen deficiency and controlled effect of RMR on BMD.

  14. Comparing the measured basal metabolic rates in patients with chronic disorders of consciousness to the estimated basal metabolic rate calculated from common predictive equations.

    Science.gov (United States)

    Xiao, Guizhen; Xie, Qiuyou; He, Yanbin; Wang, Ziwen; Chen, Yan; Jiang, Mengliu; Ni, Xiaoxiao; Wang, Qinxian; Murong, Min; Guo, Yequn; Qiu, Xiaowen; Yu, Ronghao

    2017-10-01

    Accurately predicting the basal metabolic rate (BMR) of patients in a vegetative state (VS) or minimally conscious state (MCS) is critical to proper nutritional therapy, but commonly used equations have not been shown to be accurate. Therefore, we compared the BMR measured by indirect calorimetry (IC) to BMR values estimated using common predictive equations in VS and MCS patients. Body composition variables were measured using the bioelectric impedance analysis (BIA) technique. BMR was measured by IC in 82 patients (64 men and 18 women) with VS or MCS. Patients were classified by body mass index as underweight (equations and compared to the measured BMR using Bland-Altman analyses. For the underweight group, there was a significant difference between the measured BMR values and the estimated BMR values calculated using the H-B, Schofield, and Cunningham equations (p equations were different significantly from the measured BMR (p equations, only Schofield was not significantly different from the measured BMR in the normal-weight group. The Schofield equation showed the best concordance (only 41.5%) with the BMR values measured by IC. None of the commonly used equations to estimate BMR were suitable for the VS or MCS populations. Indirect calorimetry is the preferred way to avoid either over or underestimate of BMR values. Copyright © 2016. Published by Elsevier Ltd.

  15. Effects of carbohydrate quantity and glycemic index on resting metabolic rate and body composition during weight loss

    Science.gov (United States)

    Objective: To examine the effects of diets varying in carbohydrate and glycemic index (GI) on changes in body composition, resting metabolic rate (RMR), and metabolic adaptation during and after weight loss. Methods: Adults with obesity (n = 91) were randomized to one of four provided-food diets f...

  16. Hyperpolarized [1-13C]-acetate Renal Metabolic Clearance Rate Mapping

    DEFF Research Database (Denmark)

    Mikkelsen, Emmeli F R; Mariager, Christian Østergaard; Nørlinger, Thomas

    2017-01-01

    of furosemide, a loop diuretic known to alter both the hemodynamics and oxygen consumption in the kidney. The metabolic clearance rates (MCR) were estimated and compared between the two modalities experimentally in vivo and in simulations. There was a clear dependency on the mean transit time and MCR for both...... 13C-acetate and 11C-acetate following furosemide administration, while no dependencies on the apparent renal perfusion were observed. This study demonstrated that hyperpolarized 13C-acetate MRI is feasible for measurements of the intrarenal energetic demand via the MCR, and that the quantitative...

  17. Post-natal exposure to corticosterone affects standard metabolic rate in the zebra finch (Taeniopygia guttata).

    Science.gov (United States)

    Spencer, K A; Verhulst, S

    2008-01-01

    Post-natal stress has been shown to have important short and long term effects on many adult traits in birds. During stress, metabolic alterations often result in the mobilization of energy away from energy-sensitive functions such as growth, which could have significant implications for developing animals. However, little is known about the implications of stress hormones for energy consumption in growing individuals. We experimentally increased corticosterone (CORT) levels in nestling zebra finches via oral administration, between the ages of 7 and 18 days. The standard metabolic rate (SMR) of birds was measured twice overnight when birds were between 11-13 and 55-65 days of age. Developmental CORT administration significantly elevated overnight variability in SMR (sd) in nestling birds (during the treatment period), but not at 55-65 days (5-6 weeks after the treatment period). The effect on variability was seen more prominently in birds from larger brood sizes and in females. We found no effects of our treatments on mean SMR overnight. However, brood size and sex had interactive effects, with males from larger brood sizes having higher SMR at 55-65 days of age. These results suggest that stress hormones can have significant effects on energy metabolism and possibly nocturnal arousal and sleep fragmentation. However, there were no detectable long term effects of our treatments on SMR, suggesting that these effects are only short-lived, in order to maintain homeostasis in the short term.

  18. Advancing City Sustainability via Its Systems of Flows: The Urban Metabolism of Birmingham and Its Hinterland

    Directory of Open Access Journals (Sweden)

    Susan E. Lee

    2016-03-01

    Full Text Available Cities are dependent on their hinterlands for their function and survival. They provide resources such as people, materials, water, food and energy, as well as areas for waste disposal. Over the last 50 years, commerce and trade has become increasingly global with resources sourced from further afield often due to cheap labour costs, better transportation and a plentiful supply of energy and raw materials. However, the use and transportation of resources is becoming increasingly unsustainable as the global population increases, raw materials become increasing scarce, and energy costs rise. This paper builds on research undertaken in the Liveable Cities Programme on the resource flows of Birmingham, UK. It investigates how people, material, and food flows interact within regional, national, and international hinterlands through road and rail transportation and assesses their sustainability across all three pillars (economic, social, and environmental. The type and weight of goods is highlighted together with their costs and energy used. For a city to move with greatest effect towards sustainability it needs to: (i source as much as it can locally, to minimise transportation and energy costs; (ii adopt such principles as the “circular economy”; and (iii provide clean and efficient means to move people, especially public transportation.

  19. Interaction of carbohydrate metabolism and rat liquid gastric emptying in sustained running.

    Science.gov (United States)

    Chang, Full-Young; Lu, Ching-Liang; Lee, Shou-Dong; Doong, Ming-Luen; Yeh, Jiun-Yih; Wang, Paulus S

    2006-05-01

    Moderate to severe running usually leads to gastrointestinal dysmotility and critical energy exhaustion. It is unknown whether the carbohydrate metabolism of runners can influence gastric emptying (GE). Using a running rat model, the present study explored the impact of exercise/carbohydrate metabolism on liquid GE. Rats were put on the runways of a moving treadmill for 1 h. Trained rats underwent daily running 5 days a week for 4 weeks. Untrained rats were those put on a quiet treadmill to serve as sham exercise. On the motility study day, trained and untrained rats ran for 45 min. After orogastric feeding of radiochromium marker, they resumed running for an additional 15 min and were then killed in order to measure GE. Another group of trained and untrained rats received lactate infusion for 1 h in the quiet condition to measure their GE. The third group of rats received glucose infusion during running to measure GE. Running of untrained (P untrained rats rather than the trained counterparts had diminished plasma glucose level (P untrained (P untrained (P untrained rats during running was not only to correct hypoglycemia (P untrained rats.

  20. Metabolic Changes in Synechocystis PCC6803 upon Nitrogen-Starvation: Excess NADPH Sustains Polyhydroxybutyrate Accumulation

    Directory of Open Access Journals (Sweden)

    Waldemar Hauf

    2013-02-01

    Full Text Available Polyhydroxybutyrate (PHB is a common carbon storage polymer among heterotrophic bacteria. It is also accumulated in some photoautotrophic cyanobacteria; however, the knowledge of how PHB accumulation is regulated in this group is limited. PHB synthesis in Synechocystis sp. PCC 6803 is initiated once macronutrients like phosphorus or nitrogen are limiting. We have previously reported a mutation in the gene sll0783 that impairs PHB accumulation in this cyanobacterium upon nitrogen starvation. In this study we present data which explain the observed phenotype. We investigated differences in intracellular localization of PHB synthase, metabolism, and the NADPH pool between wild type and mutant. Localization of PHB synthase was not impaired in the sll0783 mutant; however, metabolome analysis revealed a difference in sorbitol levels, indicating a more oxidizing intracellular environment than in the wild type. We confirmed this by directly measuring the NADPH/NADP ratio and by altering the intracellular redox state of wild type and sll0783 mutant. We were able to physiologically complement the mutant phenotype of diminished PHB synthase activity by making the intracellular environment more reducing. Our data illustrate that the NADPH pool is an important factor for regulation of PHB biosynthesis and metabolism, which is also of interest for potential biotechnological applications.

  1. Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

    Science.gov (United States)

    Martin, Thomas E.; Ton, Riccardo; Nikilson, Alina

    2013-01-01

    Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

  2. KABAM Version 1.0 User's Guide and Technical Documentation - Appendix H - Methods for Estimating Metabolism Rate Constant

    Science.gov (United States)

    Appendix H of KABAM Version 1.0 documentation related to estimating the metabolism rate constant. KABAM is a simulation model used to predict pesticide concentrations in aquatic regions for use in exposure assessments.

  3. Metabolic Rate and Perceived Exertion of Walking in Older Adults With Idiopathic Chronic Fatigue.

    Science.gov (United States)

    Valiani, Vincenzo; Corbett, Duane B; Knaggs, Jeffrey D; Manini, Todd M

    2016-11-01

    Fatigue is a common complaint in older adults, often not associated with underlying medical conditions. The purpose of this study was to investigate metabolic rate (MR) of walking, walking performance, and perception-based exertion during walking in older adults with and without idiopathic chronic fatigue (ICF). 20 older adults (aged 70.8±4.9 years), reporting 2 SD above normative values of the Functional Assessment of Chronic Illness Therapy-Fatigue scale and without overt health conditions that explained their symptoms, were compared with 25 age-matched older adults (73.2±5.1 years) without fatigue symptoms. Participants walked 400 m at a rapid pace on a 20-m course. On a separate visit, oxygen consumption was measured during treadmill test at standard (40.2 m/min), preferred paces (40-83 m/min) and peak capacity. Ratings of perceived exertion (RPE) were measured at each treadmill stage and after each lap of the 400-m walk test. During the 400-m walk test, individuals with ICF showed lower overall walking speed and reported a steady increase in RPE with no change observed in non-fatigued group (1.63±1.72 vs 0.27±0.68, p < .01). Similar findings on RPE were noted on treadmill test. Gross MR, mass-specific MR, mass-specific net MR, and MR as a percent of peak oxygen consumption of walking were similar between groups during standard, preferred paces and peak capacity on treadmill. This study suggests that ICF in older adults is not related to elevated metabolic cost of walking. Higher RPE without concomitant decreases in performance indicate a potential disconnect between metabolic output and sensations during movement. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Cold-hearted bats: uncoupling of heart rate and metabolism during torpor at subzero temperatures.

    Science.gov (United States)

    Currie, Shannon E; Stawski, Clare; Geiser, Fritz

    2017-11-07

    Many hibernating animals thermoregulate during torpor and defend their body temperature (Tb) below 10°C by an increase in metabolic rate. Above a critical temperature (Tcrit) animals usually thermoconform. We investigated the physiological responses above and below Tcrit for a small tree dwelling bat (Chalinolobus gouldii, ∼14 g) that is often exposed to subzero temperatures during winter. Through simultaneous measurement of heart rate (HR) and oxygen consumption (V̇O2) we show that the relationship between oxygen transport and cardiac function is substantially altered in thermoregulating torpid bats between 1 and -2°C, compared with thermoconforming torpid bats at mild ambient temperatures (Ta 5-20°C). Tcrit for this species was Ta 0.7±0.4°C, with a corresponding Tb of 1.8±1.2°C. Below Tcrit animals began to thermoregulate, indicated by a considerable but disproportionate increase in both HR and V̇O2 The maximum increase in HR was only 4-fold greater than the average thermoconforming minimum, compared to a 46-fold increase in V̇O2 The differential response of HR and V̇O2 to low Ta was reflected in a 15-fold increase in oxygen delivery per heart beat (cardiac oxygen pulse). During torpor at low Ta, thermoregulating bats maintained a relatively slow HR and compensated for increased metabolic demands by significantly increasing stroke volume and tissue oxygen extraction. Our study provides new information on the relationship between metabolism and HR in an unstudied physiological state that may occur frequently in the wild and can be extremely costly for heterothermic animals. © 2017. Published by The Company of Biologists Ltd.

  5. Methods matter: considering locomotory mode and respirometry technique when estimating metabolic rates of fishes

    Science.gov (United States)

    Rummer, Jodie L.; Binning, Sandra A.; Roche, Dominique G.; Johansen, Jacob L.

    2016-01-01

    Respirometry is frequently used to estimate metabolic rates and examine organismal responses to environmental change. Although a range of methodologies exists, it remains unclear whether differences in chamber design and exercise (type and duration) produce comparable results within individuals and whether the most appropriate method differs across taxa. We used a repeated-measures design to compare estimates of maximal and standard metabolic rates (MMR and SMR) in four coral reef fish species using the following three methods: (i) prolonged swimming in a traditional swimming respirometer; (ii) short-duration exhaustive chase with air exposure followed by resting respirometry; and (iii) short-duration exhaustive swimming in a circular chamber. We chose species that are steady/prolonged swimmers, using either a body–caudal fin or a median–paired fin swimming mode during routine swimming. Individual MMR estimates differed significantly depending on the method used. Swimming respirometry consistently provided the best (i.e. highest) estimate of MMR in all four species irrespective of swimming mode. Both short-duration protocols (exhaustive chase and swimming in a circular chamber) produced similar MMR estimates, which were up to 38% lower than those obtained during prolonged swimming. Furthermore, underestimates were not consistent across swimming modes or species, indicating that a general correction factor cannot be used. However, SMR estimates (upon recovery from both of the exhausting swimming methods) were consistent across both short-duration methods. Given the increasing use of metabolic data to assess organismal responses to environmental stressors, we recommend carefully considering respirometry protocols before experimentation. Specifically, results should not readily be compared across methods; discrepancies could result in misinterpretation of MMR and aerobic scope. PMID:27382471

  6. Standard metabolic rate is associated with gestation duration, but not clutch size, in speckled cockroaches Nauphoeta cinerea.

    Science.gov (United States)

    Schimpf, Natalie G; Matthews, Philip G D; White, Craig R

    2012-12-15

    Metabolic rate varies significantly between individuals, and these differences persist even when the wide range of biotic and abiotic factors that influence metabolism are accounted for. It is important to understand the life history implications of variation in metabolic rate, but they remain poorly characterised despite a growing body of work examining relationships between metabolism and a range of traits. In the present study we used laboratory-bred families (one sire to three dams) of Nauphoeta cinerea (Olivier) (speckled cockroaches) to examine the relationship between standard metabolic rate (SMR) and reproductive performance (number of offspring and gestation duration). We show that SMR is negatively associated with female gestation duration. Age at mating is negatively associated with gestation duration for females, and mass is negatively associated with the average gestation duration of the females a male was mated with. In addition to the results in the current literature, the results from the present study suggest that the association between metabolism and life history is more complex than simple relationships between metabolism and various fitness traits. Future work should consider longitudinal, ontogenetic as well as selective and quantitative genetic breeding approaches to fully examine the associations between metabolism and fitness.

  7. Individual condition, standard metabolic rate, and rearing temperature influence steelhead and rainbow trout (Oncorhynchus mykiss) life histories

    Science.gov (United States)

    Matthew R. Sloat; Gordon H. Reeves

    2014-01-01

    We reared juvenile Oncorhychus mykiss with low and high standard metabolic rates (SMR) under alternative thermal regimes to determine how these proximate factors influence life histories in a partially migratory salmonid fish. High SMR significantly decreased rates of freshwater maturation and increased rates of smoltification in females, but not...

  8. The Pandolf equation under-predicts the metabolic rate of contemporary military load carriage.

    Science.gov (United States)

    Drain, Jace R; Aisbett, Brad; Lewis, Michael; Billing, Daniel C

    2017-11-01

    This investigation assessed the accuracy of error of the Pandolf load carriage energy expenditure equation when simulating contemporary military conditions (load distribution, external load and walking speed). Within-participant design. Sixteen male participants completed 10 trials comprised of five walking speeds (2.5, 3.5, 4.5, 5.5 and 6.5km·h -1 ) and two external loads (22.7 and 38.4kg). The Pandolf equation demonstrated poor predictive precision, with a mean bias of 124.9W and -48.7 to 298.5W 95% limits of agreement. Furthermore, the Pandolf equation systematically under-predicted metabolic rate (pload combinations. Predicted metabolic rate error ranged from 12-33% across all conditions with the 'moderate' walking speeds (i.e. 4.5-5.5km·h -1 ) yielding less prediction error (12-17%) when compared to the slower and faster walking speeds (21-33%). Factors such as mechanical efficiency and load distribution contribute to the impaired predictive accuracy. The authors suggest the Pandolf equation should be applied to military load carriage with caution. Copyright © 2017 Sports Medicine Australia. All rights reserved.

  9. Factor analysis of regional cerebral glucose metabolic rates in healthy men

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, Z.; Camargo, E.E.; Sostre, S.; Shafique, I.; Sadzot, B.; Links, J.M.; Dannals, R.F.; Wagner, H.N. Jr. (Johns Hopkins Medical Institutions, Baltimore, MA (United States). Div. of Nuclear Medicine Johns Hopkins Medical Institutions, Baltimore, MA (United States). Div. of Radiation Health Sciences)

    1992-07-01

    Cerebral glucose utilization measured with fluorine-18-fluoro-2-deoxy-D-glucose is characterized by considerable variability both among different persons and for the same person examined on different occasions. The goal of this study was to explore whether some regions of the brain were more variable than others with respect to glucose utilization and whether there was a pattern in their covariance. The global and regional cerebral utilization of glucose was measured in 12 healthy young volunteers on 3 or 4 occasions. In all, 24 regions were examined. The interrelation of the glucose utilization rates of the brain regions was investigated by factor analysis of the metabolic rates. Some 70% of the total variance was attributable to only 1 factor, while 80% of the total variance could be attributed to 2 factors. Regions making up the first factor were the frontal and temporal cortex, cingulate gyrus, caudate nucleus, thalamus and putamen. These regions are functionally related to the limbic system. Regions of the second factor were the parietal cortex, occipital cortex and cerebellum, regions more clearly related to sensory and motor functions. The 2-factor pattern was highly reproducible, being found with different algorithms for factor extraction and rotation. Under resting conditions, the variance of cerebral metabolism seems to be primarily related to regions which are closely involved with the limbic system. Cortical regions involved primarily in motor and sensory functions have less influence on the variance. (orig.).

  10. The effect of long term combined yoga practice on the basal metabolic rate of healthy adults

    Directory of Open Access Journals (Sweden)

    Nagendra HR

    2006-08-01

    Full Text Available Abstract Background Different procedures practiced in yoga have stimulatory or inhibitory effects on the basal metabolic rate when studied acutely. In daily life however, these procedures are usually practiced in combination. The purpose of the present study was to investigate the net change in the basal metabolic rate (BMR of individuals actively engaging in a combination of yoga practices (asana or yogic postures, meditation and pranayama or breathing exercises for a minimum period of six months, at a residential yoga education and research center at Bangalore. Methods The measured BMR of individuals practicing yoga through a combination of practices was compared with that of control subjects who did not practice yoga but led similar lifestyles. Results The BMR of the yoga practitioners was significantly lower than that of the non-yoga group, and was lower by about 13 % when adjusted for body weight (P Conclusion This study shows that there is a significantly reduced BMR, probably linked to reduced arousal, with the long term practice of yoga using a combination of stimulatory and inhibitory yogic practices.

  11. Effects of dietary quality on basal metabolic rate and internal morphology of European starlings (Sturnus vulgaris)

    Science.gov (United States)

    Geluso, Keith; Hayes, J.P.

    1999-01-01

    European starlings (Sturnus vulgaris) were fed either a low- or high-quality diet to test the effects of dietary quality on basal metabolic rate (BMR) and internal morphology. Basal metabolic rate did not differ significantly between the two dietary groups, but internal morphology differed greatly. Starlings fed the low-quality diet had heavier gastrointestinal tracts, gizzards, and livers. Starlings fed the high-quality diet had heavier breast muscles. Starlings on the low-quality diet maintained mass, while starlings on the high-quality diet gained mass. Dry matter digestibility and energy digestibility were lower for starlings fed the low-quality diet, and their food and water intake were greater than starlings on the high-quality diet. The lack of dietary effect on BMR may be the result of increased energy expenditure of digestive organs paralleling a reduction of energy expenditure of organs and tissues not related to digestion (i.e., skeletal muscle). This trade-off in energy allocation among organs suggests a mechanism by which organisms may alter BMR in response to a change in seasonal variation in food availability.

  12. Energy analysis for a sustainable future multi-scale integrated analysis of societal and ecosystem metabolism

    CERN Document Server

    Giampietro, Mario; Sorman, Alevgül H

    2013-01-01

    The vast majority of the countries of the world are now facing an imminent energy crisis, particularly the USA, China, India, Japan and EU countries, but also developing countries having to boost their economic growth precisely when more powerful economies will prevent them from using the limited supply of fossil energy. Despite this crisis, current protocols of energy accounting have been developed for dealing with fossil energy exclusively and are therefore not useful for the analysis of alternative energy sources. The first part of the book illustrates the weakness of existing analyses of energy problems: the science of energy was born and developed neglecting the issue of scale. The authors argue that it is necessary to adopt more complex protocols of accounting and analysis in order to generate robust energy scenarios and effective assessments of the quality of alternative energy sources. The second part of the book introduces the concept of energetic metabolism of modern societies and uses empirical res...

  13. Metabolic processes sustaining the reviviscence of lichen Xanthoria elegans (Link) in high mountain environments.

    Science.gov (United States)

    Aubert, Serge; Juge, Christine; Boisson, Anne-Marie; Gout, Elisabeth; Bligny, Richard

    2007-10-01

    To survive in high mountain environments lichens must adapt themselves to alternating periods of desiccation and hydration. Respiration and photosynthesis of the foliaceous lichen, Xanthoria elegans, in the dehydrated state were below the threshold of CO2-detection by infrared gas analysis. Following hydration, respiration totally recovered within seconds and photosynthesis within minutes. In order to identify metabolic processes that may contribute to the quick and efficient reactivation of lichen physiological processes, we analysed the metabolite profile of lichen thalli step by step during hydration/dehydration cycles, using 31P- and 13C-NMR. It appeared that the recovery of respiration was prepared during dehydration by the accumulation of a reserve of gluconate 6-P (glcn-6-P) and by the preservation of nucleotide pools, whereas glycolytic and photosynthetic intermediates like glucose 6-P and ribulose 1,5-diphosphate were absent. The large pools of polyols present in both X. elegans photo- and mycobiont are likely to contribute to the protection of cell constituents like nucleotides, proteins, and membrane lipids, and to preserve the integrity of intracellular structures during desiccation. Our data indicate that glcn-6-P accumulated due to activation of the oxidative pentose phosphate pathway, in response to a need for reducing power (NADPH) during the dehydration-triggered down-regulation of cell metabolism. On the contrary, glcn-6-P was metabolised immediately after hydration, supplying respiration with substrates during the replenishment of pools of glycolytic and photosynthetic intermediates. Finally, the high net photosynthetic activity of wet X. elegans thalli at low temperature may help this alpine lichen to take advantage of brief hydration opportunities such as ice melting, thus favouring its growth in harsh high mountain climates.

  14. Metabolic clearance rate and blood production rate of testosterone and dihydrotestosterone in normal subjects, during pregnancy, and in hyperthyroidism

    Science.gov (United States)

    Saez, J. M.; Forest, M. G.; Morera, A. M.; Bertrand, J.

    1972-01-01

    The metabolic clearance rate (MCR) and blood production rate (BP) of testosterone (T) and dihydrotestosterone (DHT), the conversion of plasma testosterone to plasma dihydrotestosterone, and the renal clearance of androstenedione, testosterone, and dihydrotestosterone have been studied in man. In eight normal men, the MCRT (516±108 [SD] liters/m2/day) was significantly greater than the MCRDHT (391±71 [SD] liters/m2/day). In seven females, the MCRT (304±53 [SD] liters/m2/day) was also greater than the MCRDHT (209±45 [SD] liters/m2/day) and both values were less than their respective values in men (P hyperthyroidism, the MCR for testosterone and dihydrotestosterone were similar to those observed in pregnant females, but the conversion of testosterone into dihydrotestosterone (2.78±1.7%) (SD) was greater, and similar to that found in men. In men the production of dihydrotestosterone was 0.39±0.1 (SD) mg/day, 50% being derived from the transformation of plasma testosterone. In women the production of DHT was 0.05±0.028 (SD) mg/day, only 10% coming from testosterone. During pregnancy, the production of testosterone and dihydrotestosterone are similar to that in normal women. In three patients with testicular feminization syndrome (an adult with hyperthyroidism and two children) these two MCRs were greatly reduced compared to the normal females, but the conversion of testosterone into dihydrotestosterone was in the limits of normal male range In the normal subjects the renal clearance of androstenedione was greater than that of testosterone and dihydrotestosterone. Less than 20% of the dihydrotestosterone and less than 10% of the androstenedione in the urine is derived from the plasma dihydrotestosterone and androstenedione. PMID:5020435

  15. The association between coronary flow rate and impaired heart rate recovery in patients with metabolic syndrome: A preliminary report.

    Science.gov (United States)

    Alihanoglu, Yusuf I; Kilic, I Dogu; Evrengul, Harun; Yildiz, Bekir S; Alur, Ihsan; Uludag, Burcu; Kuru, Omur; Taskoylu, Ozgur; Kaftan, Havane Asuman

    2014-01-01

    The aim of this study is to evaluate heart rate recovery (HRR) and association between coronary flow rate and HRR in patients with metabolic syndrome (MS) who had morphologically normal coronary angiogram. Study population included 43 patients with MS and 37 control subjects without MS. All patients were selected from individuals who had recently undergone coronary angiography in our hospital and were diagnosed as having angiographically normal coronary arteries. Exercise stress test results obtained prior to coronary angiography were evaluated for calculating HRR and other parameters. In addition, coronary flow was objectively evaluated for each major coronary artery in each subject using TIMI frame count method. All HRR values calculated were detected significantly lower in MS group compared to controls (HRR first: 32 ± 9 vs. 37 ± 10; p = 0.01, second: 46 ± 11 vs. 52 ± 11; p = 0.03, third: 51 ± 12 vs. 59 ± 12; p = 0.00, fourth: 54 ± 13 vs. 61 ± 2; p = 0.02). TIMI frame counts for each major epicardial coronary artery and mean TIMI frame count were also found to be significantly higher in MS group compared to controls (left anterior descending artery:51 ± 24 vs. 39 ± 15; p = 0.009, left circumflex artery: 32 ± 11 vs. 24 ± 7; p = 0.001, right coronary artery: 33 ± 14 vs. 24 ± 10; p = 0.003, mean TIMI frame count: 38 ± 15 vs. 29 ± 9;p = 0.002). Additionally, significant negative correlations were also detected between HRR first minute and coronary TIMI frame count values in patients with MS. None of MS parameters did not affect HRR values, however mean TIMI frame count independently associated with HRR first minute (p = 0.04) in patients with MS. Impaired coronary blood flow occurring in MS might be a clue of autonomic dysfunction in addition to previously known endothelial dysfunction.

  16. Evaluation of rate law approximations in bottom-up kinetic models of metabolism.

    Science.gov (United States)

    Du, Bin; Zielinski, Daniel C; Kavvas, Erol S; Dräger, Andreas; Tan, Justin; Zhang, Zhen; Ruggiero, Kayla E; Arzumanyan, Garri A; Palsson, Bernhard O

    2016-06-06

    The mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question. In this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations. Overall, our work generally supports the use of approximate rate laws when

  17. Comparing maximum rate and sustainability of pacing by mechanical vs. electrical stimulation in the Langendorff-perfused rabbit heart.

    Science.gov (United States)

    Quinn, T Alexander; Kohl, Peter

    2016-12-01

    Mechanical stimulation (MS) represents a readily available, non-invasive means of pacing the asystolic or bradycardic heart in patients, but benefits of MS at higher heart rates are unclear. Our aim was to assess the maximum rate and sustainability of excitation by MS vs. electrical stimulation (ES) in the isolated heart under normal physiological conditions. Trains of local MS or ES at rates exceeding intrinsic sinus rhythm (overdrive pacing; lowest pacing rates 2.5±0.5 Hz) were applied to the same mid-left ventricular free-wall site on the epicardium of Langendorff-perfused rabbit hearts. Stimulation rates were progressively increased, with a recovery period of normal sinus rhythm between each stimulation period. Trains of MS caused repeated focal ventricular excitation from the site of stimulation. The maximum rate at which MS achieved 1:1 capture was lower than during ES (4.2±0.2 vs. 5.9±0.2 Hz, respectively). At all overdrive pacing rates for which repetitive MS was possible, 1:1 capture was reversibly lost after a finite number of cycles, even though same-site capture by ES remained possible. The number of MS cycles until loss of capture decreased with rising stimulation rate. If interspersed with ES, the number of MS to failure of capture was lower than for MS only. In this study, we demonstrate that the maximum pacing rate at which MS can be sustained is lower than that for same-site ES in isolated heart, and that, in contrast to ES, the sustainability of successful 1:1 capture by MS is limited. The mechanism(s) of differences in MS vs. ES pacing ability, potentially important for emergency heart rhythm management, are currently unknown, thus warranting further investigation. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

  18. Leucine disposal rate for assessment of amino acid metabolism in maintenance hemodialysis patients

    Science.gov (United States)

    Denny, Gerald B.; Deger, Serpil M.; Chen, Guanhua; Bian, Aihua; Sha, Feng; Booker, Cindy; Kesler, Jaclyn T.; David, Sthuthi; Ellis, Charles D.; Ikizler, T. Alp

    2016-01-01

    Background Protein energy wasting (PEW) is common in patients undergoing maintenance hemodialysis (MHD) and closely associated with poor outcomes. Insulin resistance and associated alterations in amino acid metabolism are potential pathways leading to PEW. We hypothesized that the measurement of leucine disposal during a hyperinsulinemic- euglycemic-euaminoacidemic clamp (HEAC) procedure would accurately measure the sensitivity to insulin for its actions on concomitant carbohydrate and protein metabolism in MHD patients. Methods We examined 35 MHD patients and 17 control subjects with normal kidney function by hyperinsulinemic-euglycemic clamp (HEGC) followed by HEAC clamp procedure to obtain leucine disposal rate (LDR) along with isotope tracer methodology to assess whole body protein turnover. Results The glucose disposal rate (GDR) by HEGC was 5.1 ± 2.1 mg/kg/min for the MHD patients compared to 6.3 ± 3.9 mg/kg/min for the controls (p = 0.38). The LDR during HEAC was 0.09 ± 0.03 mg/kg/min for the MHD patients compared to 0.11 ± 0.05 mg/kg/min for the controls (p = 0.009). The LDR level was correlated with whole body protein synthesis (r = 0.25; p = 0.08), with whole body protein breakdown (r = −0.38 p = 0.01) and net protein balance (r = 0.85; p < 0.001) in the overall study population. Correlations remained significant in subgroup analysis. The GDR derived by HEGC and LDR correlated well in the controls (r = 0.79, p < 0.001), but less so in the MHD patients (r = 0.58, p < 0.001). Conclusions Leucine disposal rate reliably measures amino acid utilization in MHD patients and controls in response to high dose insulin. PMID:27413537

  19. Metabolic activity and behavior of the invasive amphipod Dikerogammarus villosus and two common Central European gammarid species (Gammarus fossarum, Gammarus roeselii): Low metabolic rates may favor the invader.

    Science.gov (United States)

    Becker, Jochen; Ortmann, Christian; Wetzel, Markus A; Koop, Jochen H E

    2016-01-01

    The Ponto-Caspian amphipod Dikerogammarus villosus is one of the most successful invaders in Central European rivers. Contrary to studies on its ecology, ecophysiological studies comparing the species' physiological traits are scarce. In this context, in particular the metabolic activity of the invasive species has rarely been considered and, moreover, the few existing studies on this species report strongly deviating results. The purpose of this study was to assess the metabolic activity and behavior of D. villosus and other common European amphipod species (Gammarus fossarum, Gammarus roeselii) in relation to temperatures covering the thermal regime of the invaded habitats. Based on direct calorimetric measurements of metabolic heat dissipation at three temperature levels (5°C, 15°C and 25°C), we found the routine metabolic rate of D. villosus to be significantly lower than that of the other studied gammarid species at the medium temperature level. The estimated resting metabolic rate indicated a similar trend. At 5°C and 25°C, both routine and resting metabolic rate did not differ between species. Compared to G. fossarum and G. roeselii, D. villosus exhibited lower locomotor activity at the low and medium temperatures (5°C and 15°C). In contrast, its locomotor activity increased at the high experimental temperature (25°C). G. fossarum and G. roeselii were apparently more active than D. villosus at all studied temperatures. We conclude that D. villosus has both physiological and behavioral adaptations that lead to a reduction in metabolic energy expenditure, which is assumed to be beneficial and might contribute to its invasive success. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Insulin, IGF-I, and muscle MAPK pathway responses after sustained exercise and their contribution to growth and lipid metabolism regulation in gilthead sea bream.

    Science.gov (United States)

    Sánchez-Gurmaches, J; Cruz-Garcia, L; Ibarz, A; Fernández-Borrás, J; Blasco, J; Gutiérrez, J; Navarro, I

    2013-10-01

    Herein, we studied whether sustained exercise positively affects growth of gilthead sea bream by alterations in a) plasma concentrations of insulin and IGF-I, b) signaling pathways in muscle, or c) regulation of lipid metabolism. Specifically, we evaluated the effects of moderated swimming (1.5 body lengths per second; BL/s) on the circulating concentrations of insulin and IGF-I, morphometric parameters, and expression of genes related to lipid metabolism in gilthead sea bream (80-90 g BW). Exercise increased the specific growth rate (P growth and metabolic homeostasis during swimming. The observed decrease in plasma insulin concentrations (P = 0.016) could favor the mobilization of tissue reserves in exercised fish. In this sense, the increase in liver fatty acid content (P = 0.041) and the changes in expression of peroxisome proliferator-activated receptors PPARα (P = 0.017) and PPARγ (P = 0.033) indicated a hepatic lipid mobilization. Concentration of glycogen in both white and red muscles was decreased (P = 0.021 and P = 0.017, respectively) in exercised (n = 12) relative to control (n = 12) gilthead sea bream, whereas concentrations of glucose (P = 0.016) and lactate (P = 0.0007) were decreased only in red muscle, indicating the use of these substrates. No changes in the glucose transporter and in lipoprotein lipase mRNA expression were found in any of the tissues studied. Exercised sea bream had decreased content of PPARβ mRNA in white and red muscle relative to control sea bream expression (P = 0.001 and P = 0.049, respectively). Mitogen-activated protein kinase phosphorylation was significantly down-regulated in both white and red muscles of exercised sea bream (P = 0.0374 and P = 0.0371, respectively). Tumor necrosis factor-α expression of white muscle was down-regulated in exercised gilthead sea bream (P = 0.045). Collectively, these results contribute to the knowledge base about hormonal regulation of growth and lipid metabolism in exercised gilthead

  1. Metabolic adaptation during early lactation: key to cow health, longevity and a sustainable dairy production chain

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Hammon, H.M.; Bernabucci, U.; Bertoni, G.; Bruckmaier, R.M.; Goselink, R.M.A.; Gross, J.J.; Kuhla, B.; Metges, C.C.; Parmentier, H.K.; Trevisi, E.; Tröscher, A.; Vuuren, van A.M.

    2014-01-01

    Enhancing longevity by reducing involuntary culling and consequently increasing productive life and lifetime production of dairy cows is not only a strategy to improve a farm’s profit, but is also related to improved animal welfare. High rates of involuntary culling in dairy cows are currently

  2. Predicting metabolic rate during level and uphill outdoor walking using a low-cost GPS receiver.

    Science.gov (United States)

    de Müllenheim, Pierre-Yves; Dumond, Rémy; Gernigon, Marie; Mahé, Guillaume; Lavenu, Audrey; Bickert, Sandrine; Prioux, Jacques; Noury-Desvaux, Bénédicte; Le Faucheur, Alexis

    2016-08-01

    The objective of this study was to assess the accuracy of using speed and grade data obtained from a low-cost global positioning system (GPS) receiver to estimate metabolic rate (MR) during level and uphill outdoor walking. Thirty young, healthy adults performed randomized outdoor walking for 6-min periods at 2.0, 3.5, and 5.0 km/h and on three different grades: 1) level walking, 2) uphill walking on a 3.7% mean grade, and 3) uphill walking on a 10.8% mean grade. The reference MR [metabolic equivalents (METs) and oxygen uptake (V̇o2)] values were obtained using a portable metabolic system. The speed and grade were obtained using a low-cost GPS receiver (1-Hz recording). The GPS grade (Δ altitude/distance walked) was calculated using both uncorrected GPS altitude data and GPS altitude data corrected with map projection software. The accuracy of predictions using reference speed and grade (actual[SPEED/GRADE]) data was high [R(2) = 0.85, root-mean-square error (RMSE) = 0.68 MET]. The accuracy decreased when GPS speed and uncorrected grade (GPS[UNCORRECTED]) data were used, although it remained substantial (R(2) = 0.66, RMSE = 1.00 MET). The accuracy was greatly improved when the GPS speed and corrected grade (GPS[CORRECTED]) data were used (R(2) = 0.82, RMSE = 0.79 MET). Published predictive equations for walking MR were also cross-validated using actual or GPS speed and grade data when appropriate. The prediction accuracy was very close when either actual[SPEED/GRADE] values or GPS[CORRECTED] values (for level and uphill combined) or GPS speed values (for level walking only) were used. These results offer promising research and clinical applications related to the assessment of energy expenditure during free-living walking. Copyright © 2016 the American Physiological Society.

  3. Physiological Status Drives Metabolic Rate in Mediterranean Geckos Infected with Pentastomes.

    Directory of Open Access Journals (Sweden)

    Isabel C Caballero

    Full Text Available Negative effects of parasites on their hosts are well documented, but the proximate mechanisms by which parasites reduce their host's fitness are poorly understood. For example, it has been suggested that parasites might be energetically demanding. However, a recent meta-analysis suggests that they have statistically insignificant effects on host resting metabolic rate (RMR. It is possible, though, that energetic costs associated with parasites are only manifested during and/or following periods of activity. Here, we measured CO2 production (a surrogate for metabolism in Mediterranean geckos (Hemidactylus turcicus infected with a lung parasite, the pentastome Raillietiella indica, under two physiological conditions: rested and recently active. In rested geckos, there was a negative, but non-significant association between the number of pentastomes (i.e., infection intensity and CO2 production. In recently active geckos (chased for 3 minutes, we recorded CO2 production from its maximum value until it declined to a stationary phase. We analyzed this decline as a 3 phase function (initial decline, secondary decline, stationary. Geckos that were recently active showed, in the secondary phase, a significant decrease in CO2 production as pentastome intensity increased. Moreover, duration of the secondary phase showed a significant positive association with the number of pentastomes. These results suggest that the intensity of pentastome load exerts a weak effect on the metabolism of resting geckos, but a strong physiological effect on geckos that have recently been active; we speculate this occurs via mechanical constraints on breathing. Our results provide a potential mechanism by which pentastomes can reduce gecko fitness.

  4. The rate of metabolism as a factor determining longevity of the Saccharomyces cerevisiae yeast.

    Science.gov (United States)

    Molon, Mateusz; Szajwaj, Monika; Tchorzewski, Marek; Skoczowski, Andrzej; Niewiadomska, Ewa; Zadrag-Tecza, Renata

    2016-02-01

    Despite many controversies, the yeast Saccharomyces cerevisiae continues to be used as a model organism for the study of aging. Numerous theories and hypotheses have been created for several decades, yet basic mechanisms of aging have remained unclear. Therefore, the principal aim of this work is to propose a possible mechanism leading to increased longevity in yeast. In this paper, we suggest for the first time that there is a link between decreased metabolic activity, fertility and longevity expressed as time of life in yeast. Determination of reproductive potential and total lifespan with the use of fob1Δ and sfp1Δ mutants allows us to compare the "longevity" presented as the number of produced daughters with the longevity expressed as the time of life. The results of analyses presented in this paper suggest the need for a change in the definition of longevity of yeast by taking into consideration the time parameter. The mutants that have been described as "long-lived" in the literature, such as the fob1Δ mutant, have an increased reproductive potential but live no longer than their standard counterparts. On the other hand, the sfp1Δ mutant and the wild-type strain produce a similar number of daughter cells, but the former lives much longer. Our results demonstrate a correlation between the decreased efficiency of the translational apparatus and the longevity of the sfp1Δ mutant. We suggest that a possible factor regulating the lifespan is the rate of cell metabolism. To measure the basic metabolism of the yeast cells, we used the isothermal microcalorimetry method. In the case of sfp1Δ, the flow of energy, ATP concentration, polysome profile and translational fitness are significantly lower in comparison with the wild-type strain and the fob1Δ mutant.

  5. Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers

    Energy Technology Data Exchange (ETDEWEB)

    Miletto, M.; Williams, K.H.; N' Guessan, A.L.; Lovley, D.R.

    2011-04-01

    Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations, and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a decline in dsrB transcript abundance in the Desulfobacteraceae. These results suggest that monitoring transcripts of dissimilatory (bi)sulfite reductase genes in distinct populations of sulfate reducers can provide insight into the relative rates of metabolism of different components of the sulfate-reducing community and their ability to respond to

  6. Effects of Time-Release Caffeine Containing Supplement on Metabolic Rate, Glycerol Concentration and Performance

    Directory of Open Access Journals (Sweden)

    Adam M. Gonzalez, Jay R. Hoffman, Adam J. Wells, Gerald T. Mangine, Jeremy R. Townsend, Adam R. Jajtner, Ran Wang, Amelia A. Miramonti, Gabriel J. Pruna, Michael B. LaMonica, Jonathan D. Bohner, Mattan W. Hoffman, Leonardo P. Oliveira, David H. Fukuda, Maren S. Fragala, Jeffrey R. Stout

    2015-06-01

    Full Text Available This study compared caffeine pharmacokinetics, glycerol concentrations, metabolic rate, and performance measures following ingestion of a time-release caffeine containing supplement (TR-CAF versus a regular caffeine capsule (CAF and a placebo (PL. Following a double-blind, placebo-controlled, randomized, cross-over design, ten males (25.9 ± 3.2 y who regularly consume caffeine ingested capsules containing either TR-CAF, CAF, or PL. Blood draws and performance measures occurred at every hour over an 8-hour period. Plasma caffeine concentrations were significantly greater (p < 0.05 in CAF compared to TR-CAF during hours 2-5 and significantly greater (p = 0.042 in TR-CAF compared to CAF at hour 8. There were no significant differences between trials in glycerol concentrations (p = 0.86 or metabolic measures (p = 0.17-0.91. Physical reaction time was significantly improved for CAF at hour 5 (p=0.01 compared to PL. Average upper body reaction time was significantly improved for CAF and TR-CAF during hours 1-4 (p = 0.04 and p = 0.01, respectively and over the 8-hour period (p = 0.04 and p = 0.001, respectively compared to PL. Average upper body reaction time was also significantly improved for TR-CAF compared to PL during hours 5-8 (p = 0.004. TR-CAF and CAF showed distinct pharmacokinetics yielding modest effects on reaction time, yet did not alter glycerol concentration, metabolic measures, or other performance measures.

  7. Inhibition of soluble epoxide hydrolase reduces food intake and increases metabolic rate in obese mice

    Science.gov (United States)

    do Carmo, Jussara M.; da Silva, Alexandre A.; Morgan, Jarrett; Wang, Yi-Xin (Jim); Munusamy, Shankar; Hall, John E.

    2011-01-01

    Background and Aims This study evaluated the responses to soluble epoxide hydrolase (s-EH) inhibition, an essential enzyme in the metabolism of arachidonic acid, on food intake, body weight and metabolic parameters in mice fed a high fat-high fructose diet (HFD) for 10 weeks. Methods and Results After 5 weeks of HFD, mice were divided into two groups: 1) s-EH inhibitor (AR9281, 200 mg/kg/day by gavage twice daily), and 2) vehicle (0.3 ml per gavage). Food intake, body weight, oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient (RQ), and motor activity were measured weekly for more 5 weeks. HFD increased body weight (37±1 vs 26±1 g), and plasma of glucose (316±8 vs 188±27 mg/dl), insulin (62.1±8.1 vs 15.5±5.0 µU/ml), and leptin levels (39.4±3.6 vs 7.5±0.1 ng/ml) while reducing VO2, VCO2 and motor activity. s-EH inhibition for 5 weeks decreased caloric intake by ~32% and increased VO2 by ~17% (42.8±1.4 vs. 50.2±1.5 ml/kg/min) leading to significant weight loss. Inhibition of s-EHi also caused significant reductions in plasma leptin levels and visceral fat content. Uncoupling protein 1 (UCP1) content in brown adipose tissue was also elevated by ~50% during s-EH inhibition compared to vehicle treatment. Conclusion These results suggest that s-EH inhibition with AR9281 promotes weight loss by reducing appetite and increasing metabolic rate, and that increased UCP1 content may contribute to the increase in energy expenditure. PMID:21190818

  8. Role of resting metabolic rate and energy expenditure in hunger and appetite control: a new formulation.

    Science.gov (United States)

    Blundell, John E; Caudwell, Phillipa; Gibbons, Catherine; Hopkins, Mark; Naslund, Erik; King, Neil; Finlayson, Graham

    2012-09-01

    A long-running issue in appetite research concerns the influence of energy expenditure on energy intake. More than 50 years ago, Otto G. Edholm proposed that "the differences between the intakes of food [of individuals] must originate in differences in the expenditure of energy". However, a relationship between energy expenditure and energy intake within any one day could not be found, although there was a correlation over 2 weeks. This issue was never resolved before interest in integrative biology was replaced by molecular biochemistry. Using a psychobiological approach, we have studied appetite control in an energy balance framework using a multi-level experimental system on a single cohort of overweight and obese human subjects. This has disclosed relationships between variables in the domains of body composition [fat-free mass (FFM), fat mass (FM)], metabolism, gastrointestinal hormones, hunger and energy intake. In this Commentary, we review our own and other data, and discuss a new formulation whereby appetite control and energy intake are regulated by energy expenditure. Specifically, we propose that FFM (the largest contributor to resting metabolic rate), but not body mass index or FM, is closely associated with self-determined meal size and daily energy intake. This formulation has implications for understanding weight regulation and the management of obesity.

  9. Validity of the Inbody 520™ to predict metabolic rate in apparently healthy adults.

    Science.gov (United States)

    Salacinski, Amanda J; Howell, Steven M; Hill, Danielle L

    2017-05-30

    The present study seeks to assess the validity of the InBody 520™ device to predict RMR in apparently healthy adults relative to a metabolic cart (the standard, yet time intensive, method for determining resting metabolic rate). Twenty-six apparently healthy adults participated in the study. Predicted RMR (pRMR) was calculated by the InBody 520™ and measured RMR (mRMR) was determined by 30-minute gas analysis and ventilated hood system. Of the 78 measurement trials conducted, 64 yielded acceptable measurement trials. A Pearson product-moment correlation was used to determine the relationship between pRMR and mRMR (r = .87, P < .001). No significant difference existed between the pRMR (1650.89 ± 295.96 kcal) and mRMR (1675.36 ± 278.69 kcal) values (P =.19). Study findings suggest that the InBody520™ provides valid measurements of RMR in apparently healthy adults and can be an effective and efficient method for collecting data in a clinical setting.

  10. The Acute Effects of Nonstimulant Over-the-Counter Dietary Herbal Supplements on Resting Metabolic Rate.

    Science.gov (United States)

    Salacinski, Amanda J; Howell, Steven M; Hill, Danielle L; Mauk, Steven M

    2016-01-01

    Weight loss supplements are widely advertised and highly sought out products. Many supplements claim to increase body fat utilization, increase resting metabolic rate (RMR), and to improve body composition by decreasing total body fat composition. Therefore, the purpose of this study was to determine the acute effect of nonstimulant herbal supplements on RMR and substrate utilization. Ten female and 16 male participants (mean age 23.7 ± 3.9 years; mean weight 79.2 ± 18.2 kg) completed a random-repeated measures crossover study. Participants completed a total of three RMRs by either ingesting a placebo (P) or one of two supplements [raspberry ketones (R) or metabolic activator blend (MAB)] 2 hours prior to testing. No significant difference was found for RMR for P vs. MAB (p = .130), vs. R (p = .588), and MAB vs. R (p = .636). No significant difference was found for respiratory quotient for P vs. MAB (p = .056), vs. R (p = .149), and MAB vs. R (p = .764). No significant difference was found for substrate utilization: percent carbohydrate utilization, P vs. MAB (p = .052), P vs. R (p = .124), and MAB vs. R (p = .680); and percent fat utilization, P vs. MAB (p = .052), P vs. R (p = .120), and MAB vs. R (p = .749). Therefore, nonstimulant weight loss supplements may not be beneficial for weight loss, or an increase of fat utilization.

  11. Pregnancy-related changes in activity energy expenditure and resting metabolic rate in Switzerland.

    Science.gov (United States)

    Melzer, K; Schutz, Y; Boulvain, M; Kayser, B

    2009-10-01

    To measure resting metabolic rate (RMR), activity energy expenditure (AEE), total energy expenditure (TEE) and physical activity pattern, that is, duration and intensity (in metabolic equivalents, METs) of activities performed in late pregnancy compared with postpartum in healthy, well-nourished women living in Switzerland. Weight, height, RMR, AEE, TEE and physical activity patterns were measured longitudinally in 27 healthy women aged 23-40 years at 38.2+/-1.5 weeks of gestation and 40.0+/-7.2 weeks postpartum. The RMR during late pregnancy was 7480 kJ per day, that is, 1320+/-760 kJ per day (21.4%) higher than the postpartum RMR (P or =6 (1 vs 6 min, P=0.014) during pregnancy and postpartum, respectively. Energy expenditure in healthy women living in Switzerland increases in pregnancy compared with the postpartum state. Additional energy expenditure is primarily attributed to an increase in RMR, which is partly compensated by a decrease in AEE. The decrease in physical activity-related energy costs is achieved by selecting less demanding activities and should be taken into account when defining extra energy requirements for late pregnancy in Switzerland.

  12. Relationship between serum uric acid, metabolic syndrome and resting heart rate in Chinese elderly.

    Science.gov (United States)

    Liu, Ping; Jiang, Yunqi; Meng, Juan

    2016-01-01

    Both serum uric acid (SUA) and resting heart rate (RHR) are positively associated with metabolic syndrome (MetS). However, little is known regarding the relationship between SUA and RHR. We aimed to investigate the relationship between SUA and RHR in the elderly with MetS. With a retrospective observational analysis, 867 Chinese elderly subjects (437 males and 430 females) were divided into 4 groups according to SUA quartiles. We first investigated the relationship between SUA and MetS. Then we evaluated whether there is an independent association of SUA with RHR in these subjects. There were significant differences of MetS incidence in groups of Quartile 1-4 in male and female (all P0.30, Pmetabolic risk in Chinese elderly. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  13. Differential circadian pattern of water and Na excretion rates in the metabolic syndrome.

    Science.gov (United States)

    Fezeu, Leopold; Bankir, Lise; Hansel, Boris; Guerrot, Dominique

    2014-08-01

    This study comparatively investigated the chronobiology of water and Na excretion rates (W-ExcR and Na-ExcR) in 46 non-diabetic metabolic syndrome (MS) patients. The circadian pattern of W-ExcR was independently associated with the nocturnal dipping of systolic blood pressure (β = -3.1). During oral glucose tolerance test, the rise in plasma insulin (β = 34.0) and the insulinogenic index (β = 4.1) were independently associated with the day/night ratio of W-ExcR. The circadian pattern of Na-ExcR was not significantly associated with the latter variables. This study strongly suggests that the chronobiology of mechanisms involved in the regulation of water excretion may be more specifically altered in the MS.

  14. Regional cerebral metabolic rate for glucose and cerebrospinal fluid monoamine metabolites in subacute sclerosing panencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Yanai, Kazuhiko; Miyabayashi, Shigeaki; Iinuma, Kazuie; Tada, Keiya; Fukuda, Hiroshi; Ito, Masatoshi; Matsuzawa, Taiju

    1987-06-01

    Regional cerebral metabolic rate for glucose (rCMRglu) and cerebrospinal fluid monoamine metabolites were measured in two cases of subacute sclerosing panencephalitis (SSPE) with different clinical courses. A marked decrease in rCMRglu was found in the cortical gray matter of a patient with rapidly developing SSPE (3.6 - 4.2 mg/100 g brain tissue/min). However, the rCMRglu was preserved in the caudate and lenticular nuclei of the patient (7.7 mg/100 g/min). The rCMRglu in a patient with slowly developing SSPE revealed patterns and values similar to those of the control. Cerebrospinal fluid monoamine metabolites ; homovanilic acid and 5-hydroxyindoleacetic acid, were decreased in both rapidly and slowly developing SSPE. These data indicated that rCMRglu correlated better with the neurological and psychological status and that dopaminergic and serotonergic abnormalities have been implicated in pathophysiology of SSPE.

  15. Basal metabolic rate of Colombian children 2-16 y of age: ethnicity and nutritional status.

    Science.gov (United States)

    Spurr, G B; Reina, J C; Hoffmann, R G

    1992-10-01

    Measurements of basal metabolic rate (BMR) were made in 528 children 2-16 y of age living in underprivileged areas of the city of Cali, Colombia (153 control and 186 undernourished boys, 93 control and 96 undernourished girls). The data are related to BMR calculated from the equations of Schofield and to estimates of the lean body mass (LBM). The ethnic composition of the subjects was 80% mestizo (mixed European and South Amerindian ancestry), 15% black, and 5% white. The data do not show any variations due to race in these subjects. The Schofield equations overestimate the BMR of boys by approximately 6% whereas the estimation of BMR in girls is not significantly different from measured values. More than 65% of the variation in BMR of both nutritionally normal and undernourished boys and girls is explained by variation in body size as estimated by the LBM.

  16. Effect of copper nanoparticles on metabolic rate and development of chicken embryos

    DEFF Research Database (Denmark)

    Pineda, Lane Manalili; Sawosz, E.; Vadalasetty, K. P.

    2013-01-01

    The objective of the study was to investigate the effects of an in ovo injection of CuNano and the timing of injection on metabolic rate (O consumption and heat production, HP) and development of layer hatchlings. On day 1 of incubation, 192 fertile eggs from 29-week-old Lohmann breeder strain...... chickens were distributed into four groups that were administered colloidal CuNano on: day 1 and/or 10. Gaseous exchange was measured in an open-air-circuit respiration unit, and HP was calculated for 16- and 19-day-old embryos. Yolk free body weight (YFBW) at 24h after hatching and the relative organ...... weights were used as a measure of hatchling development. In ovo injection of CuNano on different days during incubation significantly decreased O consumption and HP compared with the control group. The residual yolk sac weight in the treated groups was significantly higher than in the control group (P0...

  17. The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise

    Directory of Open Access Journals (Sweden)

    Shaun Steven Killen

    2015-04-01

    Full Text Available When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fuelled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope or recovery time after exhaustive exercise. Slower recovery ability or a reduced aerobic scope could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how aerobic scope and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden grey mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26oC, then measured for standard and maximal metabolic rates and aerobic scope using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasise that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with

  18. Familial Resemblance of Body Composition, Physical Activity, and Resting Metabolic Rate in Pre-School Children

    Directory of Open Access Journals (Sweden)

    Kurosh Djafarian

    2013-10-01

    Full Text Available Background: Although parental obesity is a well-established predisposing factor for the development of obesity, associations between regional body compositions, resting metabolic rates (RMR, and physical activity (PA of parents and their pre-school children remain unknown. The objective of this study was to investigate parent-child correlations for total and regional body compositions, resting energy expenditures, and physical activity. Methods: Participants were 89 children aged 2-6 years and their parents, consisting of 61 families. Resting metabolic rate was assessed using indirect calorimetry. Total and regional body compositions were measured by both dual energy X-ray absorptiometry (DXA and deuterium dilution. Physical activity was assessed by an accelerometer. Results: There was a significant parent-offspring regression for total fat free mass (FFM between children and their mothers (P=0.02, fathers (P=0.02, and mid-parent (average of father and mother value (P=0.002 when measured by DXA. The same was true for fat mass (FM between children and mothers (P<0.01, fathers (P=0.02, and mid-parent (P=0.001. There was no significant association between children and parents for physical activity during the entire week, weekend, weekdays, and different parts of days, except for morning activity, which was positively related to the mothers’ morning activities (P<0.01 and mid-parent (P=0.009. No association was found between RMR of children and parents before and after correction for FFM and FM. Conclusion: These data suggest a familial resemblance for total body composition between children and their parents. Our data showed no familial resemblance for PA and RMR between children and their parents.

  19. A validated disease specific prediction equation for resting metabolic rate in underweight patients with COPD

    Directory of Open Access Journals (Sweden)

    Anita Nordenson

    2010-09-01

    Full Text Available Anita Nordenson2, Anne Marie Grönberg1,2, Lena Hulthén1, Sven Larsson2, Frode Slinde11Department of Clinical Nutrition, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden; 2Department of Internal Medicine/Respiratory Medicine and Allergology, Sahlgrenska Academy at University of Gothenburg, SwedenAbstract: Malnutrition is a serious condition in chronic obstructive pulmonary disease (COPD. Successful dietary intervention calls for calculations of resting metabolic rate (RMR. One disease-specific prediction equation for RMR exists based on mainly male patients. To construct a disease-specific equation for RMR based on measurements in underweight or weight-losing women and men with COPD, RMR was measured by indirect calorimetry in 30 women and 11 men with a diagnosis of COPD and body mass index <21 kg/m2. The following variables, possibly influencing RMR were measured: length, weight, middle upper arm circumference, triceps skinfold, body composition by dual energy x-ray absorptiometry and bioelectrical impedance, lung function, and markers of inflammation. Relations between RMR and measured variables were studied using univariate analysis according to Pearson. Gender and variables that were associated with RMR with a P value <0.15 were included in a forward multiple regression analysis. The best-fit multiple regression equation included only fat-free mass (FFM: RMR (kJ/day = 1856 + 76.0 FFM (kg. To conclude, FFM is the dominating factor influencing RMR. The developed equation can be used for prediction of RMR in underweight COPD patients.Keywords: pulmonary disease, chronic obstructive, basal metabolic rate, malnutrition, body composition

  20. Effect of temperature on the standard metabolic rates of juvenile and adult Exopalaemon carinicauda

    Science.gov (United States)

    Zhang, Chengsong; Li, Fuhua; Xiang, Jianhai

    2015-03-01

    Ridgetail white prawn ( Exopalaemon carinicauda) are of significant economic importance in China where they are widely cultured. However, there is little information on the basic biology of this species. We evaluated the effect of temperature (16, 19, 22, 25, 28, 31, and 34°C) on the standard metabolic rates (SMRs) of juvenile and adult E. carinicauda in the laboratory under static conditions. The oxygen consumption rate (OCR), ammonia-N excretion rate (AER), and atomic ratio of oxygen consumed to nitrogen consumed (O:N ratio) of juvenile and adult E. carinicauda were significantly influenced by temperature ( P 0.05). The O:N ratio in juveniles was significantly higher than that in the adults over the entire temperature range ( P <0.05). The temperature coefficient ( Q 10) of OCR and AER ranged from 5.03 to 0.86 and 6.30 to 0.85 for the adults, respectively, and from 6.09-1.03 and 3.66-1.80 for the juveniles, respectively. The optimal temperature range for growth of the juvenile and adult shrimp was from 28 to 31°C, based on Q 10 and SMR values. Results from the present study may be used to guide pond culture production of E. carinicauda.

  1. Resting metabolic rate, pulmonary functions, and body composition parameters in children with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Alpaslan, Ahmet Hamdi; Ucok, Kagan; Coşkun, Kerem Şenol; Genc, Abdurrahman; Karabacak, Hatice; Guzel, Halil Ibrahim

    2017-03-01

    Several studies of school-aged children with attention deficit hyperactivity disorder (ADHD) have found a higher prevalence of overweight/obesity compared with the general population. However, the scientific literature contains insufficient evidence to establish clear conclusions on pulmonary functions, resting metabolic rate (RMR), and body composition in children with ADHD. This study therefore investigates the pulmonary functions tests (PFTs), RMR, and body composition parameters in children with ADHD and evaluates their quality of life. Forty children with ADHD and 40 healthy controls participated in the study. The children's parents completed Conners' parent rating scale (CPRS) and the pediatric quality of life (PedsQL), and their teachers completed Conners' Teacher rating scale (CTRS). The child participants also completed the PedsQL. RMR, PFTs, and body composition parameters were investigated. No significant differences in age, gender, and socioeconomic level were found. All CPRS subscales, except anxiety and psychosomatic conditions, were significantly different (p ADHD group. The results showed that the ADHD group's quality of life is worse than the control group. Body mass index, body composition parameters, RMR, and PFTs were not statistically different between the children with ADHD and the healthy controls. Further studies with complex designs are needed to confirm the results.

  2. Bringing metabolic networks to life: convenience rate law and thermodynamic constraints

    Directory of Open Access Journals (Sweden)

    Klipp Edda

    2006-12-01

    Full Text Available Abstract Background Translating a known metabolic network into a dynamic model requires rate laws for all chemical reactions. The mathematical expressions depend on the underlying enzymatic mechanism; they can become quite involved and may contain a large number of parameters. Rate laws and enzyme parameters are still unknown for most enzymes. Results We introduce a simple and general rate law called "convenience kinetics". It can be derived from a simple random-order enzyme mechanism. Thermodynamic laws can impose dependencies on the kinetic parameters. Hence, to facilitate model fitting and parameter optimisation for large networks, we introduce thermodynamically independent system parameters: their values can be varied independently, without violating thermodynamical constraints. We achieve this by expressing the equilibrium constants either by Gibbs free energies of formation or by a set of independent equilibrium constants. The remaining system parameters are mean turnover rates, generalised Michaelis-Menten constants, and constants for inhibition and activation. All parameters correspond to molecular energies, for instance, binding energies between reactants and enzyme. Conclusion Convenience kinetics can be used to translate a biochemical network – manually or automatically - into a dynamical model with plausible biological properties. It implements enzyme saturation and regulation by activators and inhibitors, covers all possible reaction stoichiometries, and can be specified by a small number of parameters. Its mathematical form makes it especially suitable for parameter estimation and optimisation. Parameter estimates can be easily computed from a least-squares fit to Michaelis-Menten values, turnover rates, equilibrium constants, and other quantities that are routinely measured in enzyme assays and stored in kinetic databases.

  3. Association of erythrocyte sedimentation rate and fibrinogen concentration with metabolic syndrome in schizophrenic patients.

    Science.gov (United States)

    Pavlović, Marko; Babić, Dragan; Rastović, Pejana; Ljevak, Ivona

    2013-06-01

    Inflammation can be a process significant to the development of schizophrenia and metabolic disorders that are frequently found in patients suffering from schizophrenia. The aim of this study was to determine the values of erythrocyte sedimentation rate and fibrinogen concentration and to establish their possible association with MS and its components in schizophrenic patients. A cross-sectional study was conducted on 200 subjects who were divided into two groups. The study group consisted of schizophrenic patients from the University Clinical Hospital Mostar (n=100), while the control group consisted of healthy subjects who came for systematic medical examinations at the infirmary of the Health Center Mostar (n=100). The diagnosis of MS was made according to NCEP-ATP III criteria, and on that basis subjects from both groups were divided into two subgroups, one with and one without MS. Inflammatory indicators that were determinated were erythrocyte sedimentation rate and fibrinogen concentration. Statistically, MS was significantly more frequent in schizophrenic subjects (46.0%) compared to the control group (29.0%) (p=0.013). Schizophrenic subjects with MS had statistically higher sedimentation rate and fibrinogen concentration compared to the schizophrenic subjects without MS, as well as compared to the control subgroup without MS. The most significant correlations discovered were for the relation of sedimentation rate with systolic (r=0.41) and diastolic (r=0.34) blood pressures. Routine monitoring of erythrocyte sedimentation rate and fibrinogen concentration might have an important role in forecasting MS development and consequent adverse cardiovascular events which are the leading cause of mortality in schizophrenic patients.

  4. Resting heart rate predicts metabolic syndrome in apparently healthy non-obese Japanese men.

    Science.gov (United States)

    Oda, Eiji; Aizawa, Yoshifusa

    2014-02-01

    Autonomic nervous dysfunction is considered to be one of the mechanisms of metabolic syndrome (MetS). The aim of this study is to investigate whether resting heart rate, a marker of autonomic nervous dysfunction, is a predictor of MetS in apparently healthy non-obese [body mass index (BMI) healthy Japanese 1,265 men and 793 women without MetS and with no history of cardiovascular disease and no use of antihypertensive, antidiabetic, or antihyperlipidemic medication at baseline. Hazard ratios (HRs) of incident MetS were calculated for each 1 SD increase in heart rate stratified by gender and obesity. Incidence of MetS for each tertile of heart rate and HRs of MetS for the highest tertile (T3) compared with the lowest tertile (T1) were calculated stratified by gender and obesity. The HRs [95% confidence intervals (CIs)] of MetS for each 1 SD increase in heart rate were 1.319 (1.035-1.681) (p = 0.025) in non-obese men, 1.172 (0.825-1.665) (p = 0.377) in obese men, 1.115 (0.773-1.608) (p = 0.560) in non-obese women, and 1.401 (0.944-2.078) (p = 0.094) in obese women adjusted for BMI, age, smoking, alcohol drinking, and physical activity. The HRs (95% CIs) of MetS for T3 were 2.138 (1.071-4.269) (p = 0.031) in non-obese men and 1.341 (0.565-3.180) (p = 0.506) in obese men adjusted for pre-existing five components of MetS, age, smoking, alcohol drinking, and physical activity. In conclusion, an increase in resting heart rate was a significant predictor of MetS in non-obese Japanese men.

  5. Validity of predictive equations for resting metabolic rate in healthy older adults.

    Science.gov (United States)

    Itoi, Aya; Yamada, Yosuke; Yokoyama, Keiichi; Adachi, Tetsuji; Kimura, Misaka

    2017-12-01

    Accurate estimation of energy expenditure in older people is important for nutritional support. The current literature contains controversial or inconsistent data regarding the resting metabolic rate (RMR, or basal metabolic rate) in older adults, including the relationship between the RMR and ethnicity. Little information about the RMR in healthy Asian older adults is available. This study was performed to examine the RMR in healthy Japanese older adults and compare it with previously established 16 equations. Thirty-two community-dwelling, healthy, and active elderly Japanese adults were enrolled (age, 64-87 years; 14 men, 18 women; mean height, 154.9 ± 8.9 cm; mean weight, 53.5 ± 9.1 kg; mean body mass index, 22.2 ± 2.5 kg/m 2 ). The RMR was measured by indirect calorimetry. The measured RMR was compared among 16 equations. Correlation analysis, a paired t test, and a Bland-Altman plot were used to assess the agreement among the equations. The average RMR was 1132 ± 178 kcal/day with 2233 ± 437 kcal/day average total energy expenditure (TEE) measured by doubly labeled water (DLW). The smallest bias was established by De Lorenzo et al.'s equation as bias ±1.96SD = 4 ± 121 kcal/day. De Lorenzo et al. and Ikeda et al.'s equations had no significant average bias both in men and women (P > 0.05). The 1.96SD of bias in six equations was within 160 kcal/day. In contrast, residuals between the measured and predicted RMR were largely correlated with the RMR in four equations. A sex-related difference in the mean bias was observed in many equations. Although the average Japanese healthy older adult has a shorter stature and lower weight than older adults in the Western population, the current data suggest that a similar predictive equation for the RMR can be applied to both Japanese and Western older adults. This study demonstrate that the De Lorenzo et al.'s or Ikeda's equation may be useful for estimating RMR in the community

  6. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals.

    Science.gov (United States)

    Frasier, Charles C

    2015-01-01

    The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymass) (b) . Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal's characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal's means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals' skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or not MMLE can

  7. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    Science.gov (United States)

    2015-01-01

    The Mass, Metabolism and Length Explanation (MMLE) was advanced in 1984 to explain the relationship between metabolic rate and body mass for birds and mammals. This paper reports on a modernized version of MMLE. MMLE deterministically computes the absolute value of Basal Metabolic Rate (BMR) and body mass for individual animals. MMLE is thus distinct from other examinations of these topics that use species-averaged data to estimate the parameters in a statistically best fit power law relationship such as BMR = a(bodymass)b. Beginning with the proposition that BMR is proportional to the number of mitochondria in an animal, two primary equations are derived that compute BMR and body mass as functions of an individual animal’s characteristic length and sturdiness factor. The characteristic length is a measureable skeletal length associated with an animal’s means of propulsion. The sturdiness factor expresses how sturdy or gracile an animal is. Eight other parameters occur in the equations that vary little among animals in the same phylogenetic group. The present paper modernizes MMLE by explicitly treating Froude and Strouhal dynamic similarity of mammals’ skeletal musculature, revising the treatment of BMR and using new data to estimate numerical values for the parameters that occur in the equations. A mass and length data set with 575 entries from the orders Rodentia, Chiroptera, Artiodactyla, Carnivora, Perissodactyla and Proboscidea is used. A BMR and mass data set with 436 entries from the orders Rodentia, Chiroptera, Artiodactyla and Carnivora is also used. With the estimated parameter values MMLE can calculate characteristic length and sturdiness factor values so that every BMR and mass datum from the BMR and mass data set can be computed exactly. Furthermore MMLE can calculate characteristic length and sturdiness factor values so that every body mass and length datum from the mass and length data set can be computed exactly. Whether or not MMLE can

  8. Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, M.S.; Wu, J.; Haier, R.; Hazlett, E.; Ball, R.; Katz, M.; Sokolski, K.; Lagunas-Solar, M.; Langer, D.

    1987-06-22

    Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with YF-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found. A correlation between regional changes in metabolic rate and regional benzodiazepine receptor binding density from other human autopsy studies was observed; brain regions highest in receptor density showed the greatest decrease in rate.

  9. Beneficial Effects of a Dietary Weight Loss Intervention on Human Gut Microbiome Diversity and Metabolism Are Not Sustained during Weight Maintenance.

    Science.gov (United States)

    Heinsen, Femke-Anouska; Fangmann, Daniela; Müller, Nike; Schulte, Dominik M; Rühlemann, Malte C; Türk, Kathrin; Settgast, Ute; Lieb, Wolfgang; Baines, John F; Schreiber, Stefan; Franke, Andre; Laudes, Matthias

    2016-01-01

    In the present study, we examined the effect of a very low-calorie diet(VLCD)-based obesity program on human gut microbiome diversity and metabolism during weight loss and weight maintenance. Obese subjects underwent 3 months of VLCD followed by 3 months of weight maintenance. A lean and an obese control group were included. The microbiome was characterized by performing high-throughput dual-indexed 16S rDNA amplicon sequencing. At baseline, a significant difference in the Firmicutes/Bacteroidetes ratio between the lean and obese individuals was observed (p = 0.047). The VLCD resulted in significant alterations in gut microbiome diversity from baseline to 3 months (p = 0.0053). Acinetobacter represented an indicator species for the observed effect (indicator value = 0.998, p = 0.006). Metabolic analyses revealed alterations of the bacterial riboflavin pathway from baseline to 3 months (pnom = 0.0078). These changes in diversity and bacterial metabolism induced by VLCD diminished during the weight maintenance phase, despite sustained reductions in body weight and sustained improvements of insulin sensitivity. The present data show that a VLCD is able to beneficially alter both gut microbiome diversity and metabolism in obese humans, but that these changes are not sustained during weight maintenance. This finding might suggest that the microbiome should be targeted during obesity programs. © 2016 The Author(s) Published by S. Karger GmbH, Freiburg.

  10. Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

    Directory of Open Access Journals (Sweden)

    David L Swanson

    Full Text Available The underlying assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR and maximal aerobic metabolic rates are phenotypically linked. However, because BMR is largely a function of central organs whereas maximal metabolic output is largely a function of skeletal muscles, the mechanistic underpinnings for their linkage are not obvious. Interspecific studies in birds generally support a phenotypic correlation between BMR and maximal metabolic output. If the aerobic capacity model is valid, these phenotypic correlations should also extend to intraspecific comparisons. We measured BMR, M(sum (maximum thermoregulatory metabolic rate and MMR (maximum exercise metabolic rate in a hop-flutter chamber in winter for dark-eyed juncos (Junco hyemalis, American goldfinches (Carduelis tristis; M(sum and MMR only, and black-capped chickadees (Poecile atricapillus; BMR and M(sum only and examined correlations among these variables. We also measured BMR and M(sum in individual house sparrows (Passer domesticus in both summer, winter and spring. For both raw metabolic rates and residuals from allometric regressions, BMR was not significantly correlated with either M(sum or MMR in juncos. Moreover, no significant correlation between M(sum and MMR or their mass-independent residuals occurred for juncos or goldfinches. Raw BMR and M(sum were significantly positively correlated for black-capped chickadees and house sparrows, but mass-independent residuals of BMR and M(sum were not. These data suggest that central organ and exercise organ metabolic levels are not inextricably linked and that muscular capacities for exercise and shivering do not necessarily vary in tandem in individual birds. Why intraspecific and interspecific avian studies show differing results and the significance of these differences to the aerobic capacity model are unknown, and resolution of these questions will require additional studies of potential

  11. The effects of weekly exercise time on VO2max and resting metabolic rate in normal adults.

    Science.gov (United States)

    Gim, Mi-Na; Choi, Jung-Hyun

    2016-04-01

    [Purpose] The present study examined the effect of individual weekly exercise time on resting metabolic rate and VO2max (maximal oxygen uptake), which are important components of individual health indexes. [Subjects and Methods] Thirty healthy adults participated in this study. Questionnaires were used to divide the participants into groups based on average weekly walking. Resting metabolic rate was measured using a respiratory gas analyzer. Graded exercise tests were conducted using a treadmill, and the modified Bruce protocol was used as an exercise test method. [Results] VO2max, anaerobic threshold, and resting metabolic rate were significantly different among the groups. [Conclusion] Average weekly exercise time affected VO2max, resting metabolic rate, and anaerobic threshold, all of which are indicators of individual physical ability and health. These values increased as the individual amount of exercise increased. In addition, VO2max, resting metabolic rate, and anaerobic threshold were found to be closely correlated. These findings were consistent with the results of similar previous studies.

  12. Effects of season, temperature, and body mass on the standard metabolic rate of tegu lizards (Tupinambis merianae).

    Science.gov (United States)

    Toledo, Luís F; Brito, Simone P; Milsom, William K; Abe, Augusto S; Andrade, Denis V

    2008-01-01

    Abstract This study examined how the standard metabolic rate of tegu lizards, a species that undergoes large ontogenetic changes in body weight with associated changes in life-history traits, is affected by changes in body mass, body temperature, season, and life-history traits. We measured rates of oxygen consumption (Vo(2)) in 90 individuals ranging in body mass from 10.4 g to 3.75 kg at three experimental temperatures (17 degrees , 25 degrees , and 30 degrees C) over the four seasons. We found that standard metabolic rate scaled to the power of 0.84 of body mass at all experimental temperatures in all seasons and that thermal sensitivity of metabolism was relatively low (Q(10) approximately 2.0-2.5) over the range from 17 degrees to 30 degrees C regardless of body size or season. Metabolic rates did vary seasonally, being higher in spring and summer than in autumn and winter at the same temperatures, and this was true regardless of animal size. Finally, in this study, the changes in life-history traits that occurred ontogenetically were not accompanied by significant changes in metabolic rate.

  13. Low rates of lateral gene transfer among metabolic genes define the evolving biogeochemical niches of archaea through deep time.

    Science.gov (United States)

    Blank, Carrine E

    2012-01-01

    Phylogenomic analyses of archaeal genome sequences are providing windows into the group's evolutionary past, even though most archaeal taxa lack a conventional fossil record. Here, phylogenetic analyses were performed using key metabolic genes that define the metabolic niche of microorganisms. Such genes are generally considered to have undergone high rates of lateral gene transfer. Many gene sequences formed clades that were identical, or similar, to the tree constructed using large numbers of genes from the stable core of the genome. Surprisingly, such lateral transfer events were readily identified and quantifiable, occurring only a relatively small number of times in the archaeal domain of life. By placing gene acquisition events into a temporal framework, the rates by which new metabolic genes were acquired can be quantified. The highest lateral transfer rates were among cytochrome oxidase genes that use oxygen as a terminal electron acceptor (with a total of 12-14 lateral transfer events, or 3.4-4.0 events per billion years, across the entire archaeal domain). Genes involved in sulfur or nitrogen metabolism had much lower rates, on the order of one lateral transfer event per billion years. This suggests that lateral transfer rates of key metabolic proteins are rare and not rampant.

  14. Associations between heart rate variability, metabolic syndrome risk factors, and insulin resistance.

    Science.gov (United States)

    Stuckey, Melanie I; Kiviniemi, Antti; Gill, Dawn P; Shoemaker, J Kevin; Petrella, Robert J

    2015-07-01

    The purpose of this study was to examine differences in heart rate variability (HRV) in metabolic syndrome (MetS) and to determine associations between HRV parameters, MetS risk factors, and insulin resistance (homeostasis model assessment for insulin resistance (HOMA-IR)). Participants (n = 220; aged 23-70 years) were assessed for MetS risk factors (waist circumference, blood pressure, fasting plasma glucose, triglycerides, and high-density lipoprotein cholesterol) and 5-min supine HRV (time and frequency domain and nonlinear). HRV was compared between those with 3 or more (MetS+) and those with 2 or fewer MetS risk factors (MetS-). Multiple linear regression models were built for each HRV parameter to investigate associations with MetS risk factors and HOMA-IR. Data with normal distribution are presented as means ± SD and those without as median [interquartile range]. In women, standard deviation of R-R intervals 38.0 [27.0] ms, 44.5 [29.3] ms; p = 0.020), low-frequency power (5.73 ± 1.06 ln ms(2), 6.13 ± 1.05 ln ms(2); p = 0.022), and the standard deviation of the length of the Poincaré plot (46.8 [31.6] ms, 58.4 [29.9] ms; p = 0.014) were lower and heart rate was higher (68 [13] beats/min, 64 [12] beats/min; p = 0. 018) in MetS+ compared with MetS-, with no differences in men. Waist circumference was most commonly associated with HRV, especially frequency domain parameters. HOMA-IR was associated with heart rate. In conclusion, MetS+ women had a less favourable HRV profile than MetS- women, but there were no differences in men. HOMA-IR was associated with heart rate, not HRV.

  15. Influence of menstrual cycle on thermoregulatory, metabolic, and heart rate responses to exercise at night.

    Science.gov (United States)

    Hessemer, V; Brück, K

    1985-12-01

    Ten women [mean maximal O2 uptake (VO2max), 2.81 l X min-1] exercised for 15 min on a cycle ergometer in the middle of the luteal phase (L) and in the early follicular phase (F) of the menstrual cycle at the same constant work rates (mean 122 W) and an ambient temperature of 18 degrees C. Serum progesterone averaged 44.7 nmol X l-1 in L and 0.7 nmol X l-1 in F. After a 4-h resting period, exercise was performed between 3 and 4 A.M., when the L-F core temperature difference is maximal. Preexercise esophageal (Tes), tympanic (Tty), and rectal (Tre) temperatures averaged 0.6 degrees C higher in L. During exercise Tes, Tty, and Tre averaged 0.5 degrees C higher. The thresholds for chest sweating and cutaneous vasodilation (heat clearance technique) at the thumb and forearm were elevated in L by an average of 0.47 degrees C, related to mean body temperature (Tb(es) = 0.87Tes + 0.13Tskin), Tes, Tty, or Tre. The above-threshold chest sweat rate and cutaneous heat clearances were also increased in L. The mean exercise heart rate was 170.0 beats X min-1 in L and 163.8 beats X min-1 in F. The mean exercise VO2 in L (2.21 l X min-1) was 5.2% higher than in F (2.10 l X min-1), the metabolic rate was increased in L by 5.6%, but the net efficiency was 5.3% lower. No significant L-F differences in the respiratory exchange ratio and postexercise plasma lactate were demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Determination of the Metabolic Rate and Work Arduousness Class for Workers in Coal Mines - The Results of in Situ Research

    Science.gov (United States)

    Drenda, Jan; Kułagowska, Ewa; Różański, Zenon; Pach, Grzegorz; Wrona, Paweł; Karolak, Izabela

    2017-06-01

    Considering different duties and activities among miners working in underground coal mines, their work is connected with variable metabolic rate. Determination of this rate for different workplace was the aim of the research and was the base for set up the work arduousness classes for the workplace (according to the standard PN-EN 27243). The research covered 6 coal mines, 268 workers and 1164 series of measurements. Metabolic rate was established on the base of heart rate obtained from individual pulsometers (according to the standard PN-EN ISO 8996). Measurements were supplemented by poll surveys about worker and thermal environment parameters. The results showed significant variability of average heart rate (from 87 bmp to 100 bpm) with variance coefficient 14%. Mean values of metabolic rate were from 150 W/m2 to 207 W/m2. According to the results, the most common class of work arduousness was at moderate metabolic rate (class 2 - moderate work), however, more intense work was found in headings, especially at " blind end" workplace.

  17. Validity and reproducibility of resting metabolic rate measurements in rural Bangladeshi women: comparison of measurements obtained by Medgem and by Deltatrac device

    NARCIS (Netherlands)

    Alam, D.S.; Hulshof, P.J.M.; Roordink, D.; Meltzer, M.; Yunus, M.; Salam, M.A.; Raaij, van J.M.A.

    2005-01-01

    Objective:To assess reproducibility and validity of resting metabolic rate (RMR) of Bangladeshi women as measured with the MedGem device and using the Deltatrac metabolic monitor as a reference; and (2) to evaluate the FAO/WHO/UNU basal metabolic rate (BMR)-prediction equations. Design:In each of

  18. Growth trajectory influences temperature preference in fish through an effect on metabolic rate.

    Science.gov (United States)

    Killen, Shaun S

    2014-11-01

    Most animals experience temperature variations as they move through the environment. For ectotherms, in particular, temperature has a strong influence on habitat choice. While well studied at the species level, less is known about factors affecting the preferred temperature of individuals; especially lacking is information on how physiological traits are linked to thermal preference and whether such relationships are affected by factors such feeding history and growth trajectory. This study examined these issues in the common minnow Phoxinus phoxinus, to determine the extent to which feeding history, standard metabolic rate (SMR) and aerobic scope (AS), interact to affect temperature preference. Individuals were either: 1) food deprived (FD) for 21 days, then fed ad libitum for the next 74 days; or 2) fed ad libitum throughout the entire period. All animals were then allowed to select preferred temperatures using a shuttle-box, and then measured for SMR and AS at 10 °C, estimated by rates of oxygen uptake. Activity within the shuttle-box under a constant temperature regime was also measured. In both FD and control fish, SMR was negatively correlated with preferred temperature. The SMR of the FD fish was increased compared with the controls, probably due to the effects of compensatory growth, and so these growth-compensated fish preferred temperatures that were on average 2.85 °C cooler than controls fed a maintenance ration throughout the study. Fish experiencing compensatory growth also displayed a large reduction in activity. In growth-compensated fish and controls, activity measured at 10 °C was positively correlated with preferred temperature. Individual fish prefer temperatures that vary predictably with SMR and activity level, which are both plastic in response to feeding history and growth trajectories. Cooler temperatures probably allow individuals to reduce maintenance costs and divert more energy towards growth. A reduction in SMR at cooler

  19. Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

    Directory of Open Access Journals (Sweden)

    Schilling Brian K

    2009-01-01

    Full Text Available Abstract Background Dietary supplements targeting fat loss and increased thermogenesis are prevalent within the sport nutrition/weight loss market. While some isolated ingredients have been reported to be efficacious when used at high dosages, in particular in animal models and/or via intravenous delivery, little objective evidence is available pertaining to the efficacy of a finished product taken by human subjects in oral form. Moreover, many ingredients function as stimulants, leading to increased hemodynamic responses. The purpose of this investigation was to determine the effects of a finished dietary supplement on plasma catecholamine concentration, markers of lipolysis, metabolic rate, and hemodynamics. Methods Ten resistance trained men (age = 27 ± 4 yrs; BMI = 25 ± 3 kg· m-2; body fat = 9 ± 3%; mean ± SD ingested a dietary supplement (Meltdown®, Vital Pharmaceuticals or a placebo, in a random order, double blind cross-over design, with one week separating conditions. Fasting blood samples were collected before, and at 30, 60, and 90 minutes post ingestion and were assayed for epinephrine (EPI, norepinephrine (NE, glycerol, and free fatty acids (FFA. Area under the curve (AUC was calculated for all variables. Gas samples were collected from 30–60 minutes post ingestion for measurement of metabolic rate. Heart rate and blood pressure were recorded at all blood collection times. Results AUC was greater for the dietary supplement compared to the placebo for NE (1332 ± 128 pg·mL-1·90 min-1 vs. 1003 ± 133 pg·mL-1·90 min-1; p = 0.03, glycerol (44 ± 3 μg·mL-1·90 min-1 vs. 26 ± 2 μg·mL-1·90 min-1; p -1·90 min-1 vs. 0.88 ± 0.12 mmol·L-1·90 min-1; p = 0.0003. No difference between conditions was noted for EPI AUC (p > 0.05. For all variables, values were highest at 90 minutes post ingestion. Total kilocalorie expenditure during the 30 minute collection period was 29.6% greater (p = 0.02 for the dietary supplement (35 ± 3

  20. High basal metabolic rate does not elevate oxidative stress during reproduction in laboratory mice.

    Science.gov (United States)

    Brzęk, Paweł; Książek, Aneta; Ołdakowski, Łukasz; Konarzewski, Marek

    2014-05-01

    Increased oxidative stress (OS) has been suggested as a physiological cost of reproduction. However, previous studies reported ambiguous results, with some even showing a reduction of oxidative damage during reproduction. We tested whether the link between reproduction and OS is mediated by basal metabolic rate (BMR), which has been hypothesized to affect both the rate of radical oxygen species production and antioxidative capacity. We studied the effect of reproduction on OS in females of laboratory mice divergently selected for high (H-BMR) and low (L-BMR) BMR, previously shown to differ with respect to parental investment. Non-reproducing L-BMR females showed higher oxidative damage to lipids (quantified as the level of malondialdehyde in internal organ tissues) and DNA (quantified as the level of 8-oxodG in blood serum) than H-BMR females. Reproduction did not affect oxidative damage to lipids in either line; however, it reduced damage to DNA in L-BMR females. Reproduction increased catalase activity in liver (significantly stronger in L-BMR females) and decreased it in kidneys. We conclude that the effect of reproduction on OS depends on the initial variation in BMR and varies between studied internal organs and markers of OS.

  1. Metabolic modeling of energy balances in Mycoplasma hyopneumoniae shows that pyruvate addition increases growth rate.

    Science.gov (United States)

    Kamminga, Tjerko; Slagman, Simen-Jan; Bijlsma, Jetta J E; Martins Dos Santos, Vitor A P; Suarez-Diez, Maria; Schaap, Peter J

    2017-10-01

    Mycoplasma hyopneumoniae is cultured on large-scale to produce antigen for inactivated whole-cell vaccines against respiratory disease in pigs. However, the fastidious nutrient requirements of this minimal bacterium and the low growth rate make it challenging to reach sufficient biomass yield for antigen production. In this study, we sequenced the genome of M. hyopneumoniae strain 11 and constructed a high quality constraint-based genome-scale metabolic model of 284 chemical reactions and 298 metabolites. We validated the model with time-series data of duplicate fermentation cultures to aim for an integrated model describing the dynamic profiles measured in fermentations. The model predicted that 84% of cellular energy in a standard M. hyopneumoniae cultivation was used for non-growth associated maintenance and only 16% of cellular energy was used for growth and growth associated maintenance. Following a cycle of model-driven experimentation in dedicated fermentation experiments, we were able to increase the fraction of cellular energy used for growth through pyruvate addition to the medium. This increase in turn led to an increase in growth rate and a 2.3 times increase in the total biomass concentration reached after 3-4 days of fermentation, enhancing the productivity of the overall process. The model presented provides a solid basis to understand and further improve M. hyopneumoniae fermentation processes. Biotechnol. Bioeng. 2017;114: 2339-2347. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Effects of shifts in the rate of repetitive stimulation on sustained attention

    Science.gov (United States)

    Krulewitz, J. E.; Warm, J. S.; Wohl, T. H.

    1975-01-01

    The effects of shifts in the rate of presentation of repetitive neutral events (background event rate) were studied in a visual vigilance task. Four groups of subjects experienced either a high (21 events/min) or a low (6 events/min) event rate for 20 min and then experienced either the same or the alternate event rate for an additional 40 min. The temporal occurrence of critical target signals was identical for all groups, irrespective of event rate. The density of critical signals was 12 signals/20 min. By the end of the session, shifts in event rate were associated with changes in performance which resembled contrast effects found in other experimental situations in which shift paradigms were used. Relative to constant event rate control conditions, a shift from a low to a high event rate depressed the probability of signal detections, while a shift in the opposite direction enhanced the probability of signal detections.

  3. Body weight and basal metabolic rate in childhood narcolepsy: a longitudinal study.

    Science.gov (United States)

    Wang, Zongwen; Wu, Huijuan; Stone, William S; Zhuang, Jianhua; Qiu, Linli; Xu, Xing; Wang, Yan; Zhao, Zhengqing; Han, Fang; Zhao, Zhongxin

    2016-09-01

    The aims of this study were to document the trajectory of weight gain and body mass index (BMI) in children with type 1 narcolepsy, and to analyze basal metabolic rate (BMR). A total of 65 Chinese children with type 1 narcolepsy with a disease duration ≤12 months were included. In addition, 79 healthy age-matched students were enrolled as controls. Height and body weight were measured every six months for up to 36 months to calculate BMI growth. BMR was measured using COSMED K4b2 indirect calorimetry in 34 patients and 30 healthy controls at six months. At the end of 36 months, the BMR was compared among 18 patients and 16 healthy controls. The children with type 1 narcolepsy showed higher BMIs at follow-up assessments. At the end of the study, 38.46% of the patients were obese and an additional 26.15% were overweight. The patients' BMI growth at six, 12, 18, 24 and 30 months of follow-up was significantly higher, but not at month 36. The patients' basal energy expenditure was significantly lower than that of the controls at six months but not at 36 months. BMI increased rapidly in children with type 1 narcolepsy after disease onset, but BMI growth decreased gradually with prolonged disease. Decreased BMR is an important cause underlying rapid weight gain. The gradual restoration of BMI growth and BMR in narcolepsy emphasizes the importance of compensatory metabolic mechanisms in this disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Can we rely on predicted basal metabolic rate in chronic pancreatitis outpatients?

    Science.gov (United States)

    Olesen, Søren Schou; Holst, Mette; Køhler, Marianne; Drewes, Asbjørn Mohr; Rasmussen, Henrik Højgaard

    2015-04-01

    Malnutrition is a common complication to chronic pancreatitis (CP) and many patients need nutritional support. An accurate estimation of the basal metabolic rate (BMR) is essential when appropriate nutritional support is to be initiated, but in the clinical settings BMR is cumbersome to measure. We therefore investigated whether BMR can be reliable predicted from a standard formula (the Harris-Benedict equation) in CP outpatients. Twenty-eight patients with clinical stable CP and no current alcohol abuse were enrolled. Patients were stratified according to nutritional risk using the Nutrition Risk Screening 2002 system. Body composition was estimated using bioelectrical impedance. BMR was measured using indirect calorimetry and predicted using the Harris-Benedict equation based on anthropometric data. The average predicted BMR was 1371 ± 216 kcal/day compared to an average measured BMR of 1399 ± 231 kcal/day (P = 0.4). The corresponding limits of agreement were -347 to 290 kcal/day. Twenty-two patients (79%) had a measured BMR between 85 and 115% of the predicted BMR. When analysing patients stratified according to nutritional risk profiles, no differences between predicted and measured BMR were evident for any of the risk profile subgroups (all P > 0.2). The BMR was correlated to fat free mass determined by bioelectrical impedance (rho = 0.55; P = 0.003), while no effect modification was seen from nutritional risk stratification in a linear regression analysis (P = 0.4). The Harris-Benedict equation reliable predicts the measured BMR in four out of five clinical stable CP outpatients with no current alcohol abuse. Copyright © 2015 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

  5. Novel approach for evaluation of air change rate in naturally ventilated occupied spaces based on metabolic CO2 time variation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Markov, Detelin G.

    2014-01-01

    , air-tight space, constant indoor pressure and temperature. The proposed approach for ACR evaluation can be applied to time intervals with any length, even with varying parameters of both indoor and outdoor air, in which metabolic CO2 generation rate is known and constant. This approach makes possible......IAQ in many residential buildings relies on non-organized natural ventilation. Accurate evaluation of air change rate (ACR) in this situation is difficult due to the nature of the phenomenon - intermittent infiltration-exfiltration periods of mass exchange between the room air and the outdoor air...... at low rate. This paper describes a new approach for ACR evaluation in naturally ventilated occupied spaces. Actual metabolic CO2 time variation record in an interval of time is compared with the computed variation of metabolic CO2 for the same time interval under reference conditions: sleeping occupants...

  6. Effect of sampling regime on estimation of basal metabolic rate and standard evaporative water loss using flow-through respirometry.

    Science.gov (United States)

    Cooper, C E; Withers, P C

    2010-01-01

    Strict criteria have been established for measurement of basal metabolic rate and standard evaporative water loss to ensure that data can be compared intra- and interspecifically. However, data-sampling regimes vary, from essentially continuous sampling to interrupted (switching) systems with data recorded periodically at more widely spaced intervals. Here we compare one continuous and three interrupted sampling regimes to determine whether sampling regime has a significant effect on estimation of basal metabolic rate or standard evaporative water loss. Compared to continuous 20-s sampling averaged over 20 min, sampling every 6 min and averaging over 60 min overestimated basal metabolic rate and evaporative water loss, sampling every 3 min and averaging over 21 min underestimated basal metabolic rate, and sampling every 12 min and averaging over 36 min showed no difference in estimates. Increasing the period over which the minimum mean was calculated significantly increased estimates of physiological variables. Reducing the frequency of sampling from 20 s to a longer interval of 3, 6, or 12 min underestimated basal metabolic rate but not evaporative water loss. This indicates that sampling frequency per se influences estimates of basal metabolic rate and that differences are not just an artifact of differences in the period over which the mean is calculated. Sampling regime can have a highly significant influence on estimation of standard physiological variables, although the actual differences between sampling regimes were generally small (usually <5%). Although continuous sampling is the preferred sampling regime for open-flow respirometry studies, if time and cost are prohibitive, then use of an appropriate switching system will result in smaller errors than measuring individuals continuously for shorter periods.

  7. Effectiveness of eugenol sedation to reduce the metabolic rates of cool and warm water fish at high loading densities

    Science.gov (United States)

    Cupp, Aaron R.; Hartleb, Christopher F.; Fredricks, Kim T.; Gaikowski, Mark P.

    2016-01-01

    Effects of eugenol (AQUI-S®20E, 10% active eugenol) sedation on cool water, yellow perch Perca flavescens (Mitchill), and warm water, Nile tilapia Oreochromis niloticus L. fish metabolic rates were assessed. Both species were exposed to 0, 10, 20 and 30 mg L−1 eugenol using static respirometry. In 17°C water and loading densities of 60, 120 and 240 g L−1, yellow perch controls (0 mg L−1 eugenol) had metabolic rates of 329.6–400.0 mg O2 kg−1 h−1, while yellow perch exposed to 20 and 30 mg L−1 eugenol had significantly reduced metabolic rates of 258.4–325.6 and 189.1–271.0 mg O2 kg−1 h−1 respectively. Nile tilapia exposed to 30 mg L−1 eugenol had a significantly reduced metabolic rate (424.5 ± 42.3 mg O2 kg−1 h−1) relative to the 0 mg L−1 eugenol control (546.6 ± 53.5 mg O2 kg−1 h−1) at a loading density of 120 g L−1 in 22°C water. No significant differences in metabolic rates for Nile tilapia were found at 240 or 360 g L−1 loading densities when exposed to eugenol. Results suggest that eugenol sedation may benefit yellow perch welfare at high densities (e.g. live transport) due to a reduction in metabolic rates, while further research is needed to assess the benefits of eugenol sedation on Nile tilapia at high loading densities.

  8. Testing a novel method for measuring sleeping metabolic rate in neonates.

    Science.gov (United States)

    Summer, Suzanne S; Pratt, Jesse M; Koch, Elizabeth A; Anderson, Jeffrey B

    2014-07-01

    Sleeping metabolic rate (SMR) is used as a proxy for basal metabolic rate in infants, when measurement while awake is not practical. Measuring SMR via indirect calorimetry (IC) can be useful for assessing feeding adequacy especially in compromised neonates. Standard IC equipment, including a hood placed over the head, is not designed for the smallest of patients. Our aim was to determine whether a nonstandard smaller hood measures SMR in neonates similarly compared with a standard large hood. SMR was measured in healthy neonates (controls) and those born with single-ventricle congenital heart disease (cases). Two measurements were performed: SMR using a standard large hood and SMR using a smaller hood. Time-to-steady state, minute ventilation (V̇E), and fraction of exhaled carbon dioxide (FĒCO2 ; an indicator of data quality) were also measured. Primary outcome was SMR using both hoods. Results are stated as median (interquartile range). Spearman's correlations measured association between the small and large hoods. We studied 9 controls and 7 cases. SMR in controls was not different between the small and large hoods (35.7 [15.14] vs 37.8 [7.41] kcal/kg/d, respectively). In cases, SMR with the small hood was significantly greater than that with the large hood (45.5 [4.63] vs 34.2 [8] kcal/kg/d, P < .02). FĒCO2 was significantly higher with the small hood versus the large hood in both groups, and V̇E was significantly lower with the small hood versus the large hood in controls only. The SMRs with the small and large hoods were significantly correlated in the control group (r = 0.80, P < .01). Time-to-steady state was similar in both groups regardless of hood size. SMR measured with a small hood yields results similar to those measured with a large hood in healthy neonates without affecting testing time or other aspects of the IC procedure. Furthermore, results in compromised infants suggest that a smaller hood may facilitate SMR testing in this population

  9. Investigating predictors of eating: is resting metabolic rate really the strongest proxy of energy intake?

    Science.gov (United States)

    McNeil, Jessica; Lamothe, Gilles; Cameron, Jameason D; Riou, Marie-Ève; Cadieux, Sébastien; Lafrenière, Jacynthe; Goldfield, Gary; Willbond, Stephanie; Prud'homme, Denis; Doucet, Éric

    2017-11-01

    Background: Evidence suggests that fat-free mass and resting metabolic rate (RMR), but not fat mass, are strong predictors of energy intake (EI). However, body composition and RMR do not explain the entire variance in EI, suggesting that other factors may contribute to this variance.Objective: We aimed to investigate the associations between body mass index (in kg/m2), fat mass, fat-free mass, and RMR with acute (1 meal) and daily (24-h) EI and between fasting appetite ratings and certain eating behavior traits with daily EI. We also evaluated whether RMR is a predictor of the error variance in acute and daily EI.Design: Data collected during the control condition of 7 studies conducted in Ottawa, Ontario, Canada, were included in these analyses (n = 191 and 55 for acute and daily EI, respectively). These data include RMR (indirect calorimetry), body composition (dual-energy X-ray absorptiometry), fasting appetite ratings (visual analog scales), eating behavior traits (Three-Factor Eating Questionnaire), and EI (food buffet or menu).Results: Fat-free mass was the best predictor of acute EI (R2 = 0.46; P < 0.0001). The combination of fasting prospective food consumption ratings and RMR was the best predictor of daily EI (R2 = 0.44; P < 0.0001). RMR was a statistically significant positive predictor of the error variance for acute (R2 = 0.20; P < 0.0001) and daily (R2 = 0.23; P < 0.0001) EI. RMR did, however, remain a statistically significant predictor of acute (R2 = 0.32; P < 0.0001) and daily (R2 = 0.30; P < 0.0001) EI after controlling for this error variance.Conclusions: Our findings suggest that combined measurements of appetite ratings and RMR could be used to estimate EI in weight-stable individuals. However, greater error variance in acute and daily EI with increasing RMR values was observed. Future studies are needed to identify whether greater fluctuations in daily EI over time occur with increasing RMR values. This trial was registered at clinicaltrials

  10. Molecular evolutionary rates are not correlated with temperature and latitude in Squamata: an exception to the metabolic theory of ecology?

    Science.gov (United States)

    Rolland, Jonathan; Loiseau, Oriane; Romiguier, Jonathan; Salamin, Nicolas

    2016-05-20

    The metabolic theory of ecology stipulates that molecular evolutionary rates should correlate with temperature and latitude in ectothermic organisms. Previous studies have shown that most groups of vertebrates, such as amphibians, turtles and even endothermic mammals, have higher molecular evolutionary rates in regions where temperature is high. However, the association between molecular evolutionary rates and temperature or latitude has never been tested in Squamata. We used a large dataset including the spatial distributions and environmental variables for 1,651 species of Squamata and compared the contrast of the rates of molecular evolution with the contrast of temperature and latitude between sister species. Using major axis regressions and a new algorithm to choose independent sister species pairs, we found that temperature and absolute latitude were not associated with molecular evolutionary rates. This absence of association in such a diverse ectothermic group questions the mechanisms explaining current pattern of species diversity in Squamata and challenges the presupposed universality of the metabolic theory of ecology.

  11. Exchange rate volatility and oil prices shocks and its impact on economic sustainability

    Directory of Open Access Journals (Sweden)

    Khuram Shaf

    2015-01-01

    Full Text Available Impact of exchange rate volatility has received a great attention from the last century, its importance is certain in all sectors of the economy and it affects welfare as well as social life of the economy. Exchange rate between two currencies tells the value of one currency in terms of others one. Depreciation/Appreciation of exchange rate affects economic growth in terms of trade and shifts income to/from exporting countries from/to importing countries. The factors affecting exchange rate are inflation, interest rate, foreign direct investment, government consumption expenditure and balance of trade. This research study examines the impact of oil prices and exchange rate volatility on economic growth in Germany based on 40-year annual data. Cointegration technique is applied to check the impact of macroeconomic variables on exchange rate in the long run and short run. It is estimated that imports, exports, inflation, interest rate, government consumption expenditure and foreign direct investment had significant impacts on real effective exchange rate in the long run and short run. Sin addition, Engle Granger results indicate that relationship was significant for the long run and its error correction adjustment mechanism (ECM in short a run is significant and correctly signed for Germany.

  12. Phenotypic plasticity of gas exchange pattern and water loss in Scarabaeus spretus (Coleoptera: Scarabaeidae): deconstructing the basis for metabolic rate variation.

    Science.gov (United States)

    Terblanche, John S; Clusella-Trullas, Susana; Chown, Steven L

    2010-09-01

    Investigation of gas exchange patterns and modulation of metabolism provide insight into metabolic control systems and evolution in diverse terrestrial environments. Variation in metabolic rate in response to environmental conditions has been explained largely in the context of two contrasting hypotheses, namely metabolic depression in response to stressful or resource-(e.g. water) limited conditions, or elevation of metabolism at low temperatures to sustain life in extreme conditions. To deconstruct the basis for metabolic rate changes in response to temperature variation, here we undertake a full factorial study investigating the longer- and short-term effects of temperature exposure on gas exchange patterns. We examined responses of traits of gas exchange [standard metabolic rate (SMR); discontinuous gas exchange (DGE) cycle frequency; cuticular, respiratory and total water loss rate (WLR)] to elucidate the magnitude and form of plastic responses in the dung beetle, Scarabaeus spretus. Results showed that short- and longer-term temperature variation generally have significant effects on SMR and WLR. Overall, acclimation to increased temperature led to a decline in SMR (from 0.071+/-0.004 ml CO(2) h(-1) in 15 degrees C-acclimated beetles to 0.039+/-0.004 ml CO(2) h(-1) in 25 degrees C-acclimated beetles measured at 20 degrees C) modulated by reduced DGE frequency (15 degrees C acclimation: 0.554+/-0.027 mHz, 20 degrees C acclimation: 0.257+/-0.030 mHz, 25 degrees C acclimation: 0.208+/-0.027 mHz recorded at 20 degrees C), reduced cuticular WLRs (from 1.058+/-0.537 mg h(-1) in 15 degrees C-acclimated beetles to 0.900+/-0.400 mg h(-1) in 25 degrees C-acclimated beetles measured at 20 degrees C) and reduced total WLR (from 4.2+/-0.5 mg h(-1) in 15 degrees C-acclimated beetles to 3.1+/-0.5 mg h(-1) in 25 degrees C-acclimated beetles measured at 25 degrees C). Respiratory WLR was reduced from 2.25+/-0.40 mg h(-1) in 15 degrees C-acclimated beetles to 1.60+/-0.40 mg h

  13. A mathematical framework for yield (versus rate) optimization in constraint-based modeling and applications in metabolic engineering.

    Science.gov (United States)

    Klamt, Steffen; Müller, Stefan; Regensburger, Georg; Zanghellini, Jürgen

    2018-02-07

    The optimization of metabolic rates (as linear objective functions) represents the methodical core of flux-balance analysis techniques which have become a standard tool for the study of genome-scale metabolic models. Besides (growth and synthesis) rates, metabolic yields are key parameters for the characterization of biochemical transformation processes, especially in the context of biotechnological applications. However, yields are ratios of rates, and hence the optimization of yields (as nonlinear objective functions) under arbitrary linear constraints is not possible with current flux-balance analysis techniques. Despite the fundamental importance of yields in constraint-based modeling, a comprehensive mathematical framework for yield optimization is still missing. We present a mathematical theory that allows to systematically compute and analyze yield-optimal solutions of metabolic models under arbitrary linear constraints. In particular, we formulate yield optimization as a linear-fractional program. For practical computations, we transform the linear-fractional yield optimization problem to a (higher-dimensional) linear problem. Its solutions determine the solutions of the original problem and can be used to predict yield-optimal flux distributions in genome-scale metabolic models. For the theoretical analysis, we consider the linear-fractional problem directly. Most importantly, we show that the yield-optimal solution set (like the rate-optimal solution set) is determined by (yield-optimal) elementary flux vectors of the underlying metabolic model. However, yield- and rate-optimal solutions may differ from each other, and hence optimal (biomass or product) yields are not necessarily obtained at solutions with optimal (growth or synthesis) rates. Moreover, we discuss phase planes/production envelopes and yield spaces, in particular, we prove that yield spaces are convex and provide algorithms for their computation. We illustrate our findings by a small

  14. Sustained release nitrite therapy results in myocardial protection in a porcine model of metabolic syndrome with peripheral vascular disease.

    Science.gov (United States)

    Bradley, Jessica M; Islam, Kazi N; Polhemus, David J; Donnarumma, Erminia; Brewster, Luke P; Tao, Ya-Xiong; Goodchild, Traci T; Lefer, David J

    2015-07-15

    Metabolic syndrome (MetS) reduces endothelial nitric oxide (NO) bioavailability and exacerbates vascular dysfunction in patients with preexisting vascular diseases. Nitrite, a storage form of NO, can mediate vascular function during pathological conditions when endogenous NO is reduced. The aims of the present study were to characterize the effects of severe MetS and obesity on dyslipidemia, myocardial oxidative stress, and endothelial NO synthase (eNOS) regulation in the obese Ossabaw swine (OS) model and to examine the effects of a novel, sustained-release formulation of sodium nitrite (SR-nitrite) on coronary vascular reactivity and myocardial redox status in obese OS subjected to critical limb ischemia (CLI). After 6 mo of an atherogenic diet, obese OS displayed a MetS phenotype. Obese OS had decreased eNOS functionality and NO bioavailability. In addition, obese OS exhibited increased oxidative stress and a significant reduction in antioxidant enzymes. The efficacy of SR-nitrite therapy was examined in obese OS subjected to CLI. After 3 wk of treatment, SR-nitrite (80 mg · kg(-1) · day(-1) bid po) increased myocardial nitrite levels and eNOS function. Treatment with SR-nitrite reduced myocardial oxidative stress while increasing myocardial antioxidant capacity. Ex vivo assessment of vascular reactivity of left anterior descending coronary artery segments demonstrated marked improvement in vasoreactivity to sodium nitroprusside but not to substance P and bradykinin in SR-nitrite-treated animals compared with placebo-treated animals. In conclusion, in a clinically relevant, large-animal model of MetS and CLI, treatment with SR-nitrite enhanced myocardial NO bioavailability, attenuated oxidative stress, and improved ex vivo coronary artery vasorelaxation.

  15. Difference in C3-C4 metabolism underlies tradeoff between growth rate and biomass yield in Methylobacterium extorquens AM1.

    Science.gov (United States)

    Fu, Yanfen; Beck, David A C; Lidstrom, Mary E

    2016-07-19

    Two variants of Methylobacterium extorquens AM1 demonstrated a trade-off between growth rate and biomass yield. In addition, growth rate and biomass yield were also affected by supplementation of growth medium with different amounts of cobalt. The metabolism changes relating to these growth phenomena as well as the trade-off were investigated in this study. (13)C metabolic flux analysis was used to generate a detailed central carbon metabolic flux map with both absolute and normalized flux values. The major differences between the two variants occurred at the formate node as well as within C3-C4 inter-conversion pathways. Higher relative fluxes through formyltetrahydrofolate ligase, phosphoenolpyruvate carboxylase, and malic enzyme led to higher biomass yield, while higher relative fluxes through pyruvate kinase and pyruvate dehydrogenase led to higher growth rate. These results were then tested by phenotypic studies on three mutants (null pyk, null pck mutant and null dme mutant) in both variants, which agreed with the model prediction. In this study, (13)C metabolic flux analysis for two strain variants of M. extorquens AM1 successfully identified metabolic pathways contributing to the trade-off between cell growth and biomass yield. Phenotypic analysis of mutants deficient in corresponding genes supported the conclusion that C3-C4 inter-conversion strategies were the major response to the trade-off.

  16. Effects of temperature, swimming speed and body mass on standard and active metabolic rate in vendace (Coregonus albula).

    Science.gov (United States)

    Ohlberger, Jan; Staaks, Georg; Hölker, Franz

    2007-11-01

    This study gives an integrated analysis of the effects of temperature, swimming speed and body mass on standard metabolism and aerobic swimming performance in vendace (Coregonus albula (L.)). The metabolic rate was investigated at 4, 8 and 15 degrees C using one flow-through respirometer and two intermittent-flow swim tunnels. We found that the standard metabolic rate (SMR), which increased significantly with temperature, accounted for up to 2/3 of the total swimming costs at optimum speed (U (opt)), although mean U (opt) was high, ranging from 2.0 to 2.8 body lengths per second. Net swimming costs increased with swimming speed, but showed no clear trend with temperature. The influence of body mass on the metabolic rate varied with temperature and activity level resulting in scaling exponents (b) of 0.71-0.94. A multivariate regression analysis was performed to integrate the effects of temperature, speed and mass (AMR = 0.82M (0.93) exp(0.07T) + 0.43M (0.93) U (2.03)). The regression analysis showed that temperature affects standard but not net active metabolic costs in this species. Further, we conclude that a low speed exponent, high optimum speeds and high ratios of standard to activity costs suggest a remarkably efficient swimming performance in vendace.

  17. Metabolic Energy Correlates of Heart Rate Variability Spectral Power Associated with a 900-Calorie Challenge

    Directory of Open Access Journals (Sweden)

    Richard M. Millis

    2011-01-01

    Full Text Available We studied healthy males challenged with a 900 Cal test beverage and correlated EE with the raw (ms2 and normalized units (nu of total power (TP, low frequency/high frequency (LF/HF and VLF spectral power of heart rate variability (HRV. The correlations were evaluated during 20 min of normal breathing (NB, control and 20 min of paced breathing (PB at 12 breaths⋅min−1 (0.2 Hz. EE was not significantly correlated with any of the HRV variables before the metabolic challenge. After the challenge, EE was positively correlated with LF/HF and with VLF; VLF was also positively correlated with LF/HF during both NB and PB. These findings suggest that EE may be a correlate of LF/HF and of VLF spectral power of HRV in healthy adolescent/young adult males. The association of lower resting energy expenditure with lower amounts of VLF spectral power may occur in individuals with predilections for obese phenotypes.

  18. Diet affects resting, but not basal metabolic rate of normothermic Siberian hamsters acclimated to winter.

    Science.gov (United States)

    Gutowski, Jakub P; Wojciechowski, Michał S; Jefimow, Małgorzata

    2011-12-01

    We examined the effect of different dietary supplements on seasonal changes in body mass (m(b)), metabolic rate (MR) and nonshivering thermogenesis (NST) capacity in normothermic Siberian hamsters housed under semi-natural conditions. Once a week standard hamster food was supplemented with either sunflower and flax seeds, rich in polyunsaturated fatty acids (FA), or mealworms, rich in saturated and monounsaturated FA. We found that neither of these dietary supplements affected the hamsters' normal winter decrease in m(b) and fat content nor their basal MR or NST capacity. NST capacity of summer-acclimated hamsters was lower than that of winter-acclimated ones. The composition of total body fat reflected the fat composition of the dietary supplements. Resting MR below the lower critical temperature of the hamsters, and their total serum cholesterol concentration were lower in hamsters fed a diet supplemented with mealworms than in hamsters fed a diet supplemented with seeds. These results indicate that in mealworm-fed hamsters energy expenditure in the cold is lower than in animals eating a seed-supplemented diet, and that the degree of FA unsaturation of diet affects energetics of heterotherms, not only during torpor, but also during normothermy. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Temperature dependences of growth rates and carrying capacities of marine bacteria depart from metabolic theoretical predictions

    KAUST Repository

    Huete-Stauffer, Tamara Megan

    2015-09-11

    Using the metabolic theory of ecology (MTE) framework, we evaluated over a whole annual cycle the monthly responses to temperature of the growth rates (μ) and carrying capacities (K) of heterotrophic bacterioplankton at a temperate coastal site. We used experimental incubations spanning 6oC with bacterial physiological groups identified by flow cytometry according to membrane integrity (live), nucleic acid content (HNA and LNA) and respiratory activity (CTC+). The temperature dependence of μat the exponential phase of growth was summarized by the activation energy (E), which was variable (-0.52 to 0.72 eV) but followed a seasonal pattern, only reaching the hypothesized value for aerobic heterotrophs of 0.65 eV during the spring bloom for the most active bacterial groups (live, HNA, CTC+). K (i.e. maximum experimental abundance) peaked at 4 × 106 cells mL-1 and generally covaried with μbut, contrary to MTE predictions, it did not decrease consistently with temperature. In the case of live cells, the responses of μand K to temperature were positively correlated and related to seasonal changes in substrate availability, indicating that the responses of bacteria to warming are far from homogeneous and poorly explained by MTE at our site. © FEMS 2015.

  20. In situ measurement of calling metabolic rate in an Australian mole cricket, Gryllotalpa monanka.

    Science.gov (United States)

    White, Craig R; Matthews, Philip G D; Seymour, Roger S

    2008-06-01

    Examination of the energetics of sound production usually requires measurement of species that will produce normal calls under unnatural circumstances. Such measurements are potentially compromised by stress-related changes in calling input (through a reduction in calling effort) or output (through forced use of sub-optimal singing burrows). To determine if such measurements are indeed affected by abstraction from a natural setting, we measured the energetics of song production in undisturbed mole crickets Gryllotalpa monanka and employed a new approach where the animal's singing chamber replaces the respirometry chamber normally used in studies of this type. It was therefore possible to measure metabolic rate (MR) of calling crickets in situ for animals within self-constructed burrows under natural conditions. Calling MR measured under these conditions averaged 13.5-fold higher than standard MR and 2.2-fold higher than MR measured during burrowing in the lab. The calling MR of G. monanka was similar to that measured for other calling insects, and to endothermic insects, but was only 10% of that allometrically predicted for a similarly sized insect (0.89 g) during flight. A male mole cricket is estimated to consume 5.9 ml of oxygen during construction of a calling burrow and a 1-h calling bout; by comparison, a flying female would consume a similar volume in less than 6 min.

  1. Basal metabolic rate and body composition of elite Japanese male athletes.

    Science.gov (United States)

    Koshimizu, Takako; Matsushima, Yoshiko; Yokota, Yukari; Yanagisawa, Kae; Nagai, Satsuki; Okamura, Koji; Komatsu, Yutaka; Kawahara, Takashi

    2012-01-01

    The estimated energy requirement is important for adequate nutritional management in athletes. The energy requirement can be estimated from the basal metabolic rate (BMR). However, there is little data regarding the BMR of Japanese athletes. This study measured the BMR and body composition of 81 elite Japanese male athletes in different sports categories: endurance (E), strength, power and sprint (S) and ball game (B). The factors influencing the BMR were also investigated. The BMR and body composition were measured by indirect calorimetry and an air-displacement plentysmograph device (the BOD POD), respectively. The BMR per lean body mass (LBM) differed significantly among the three groups. The BMR was significantly correlated with the body weight (BW) and LBM in all groups. A multiple-regression analysis showed that the LBM was the most powerful predictor in the E and S groups, whereas the BW was the most powerful predictor in the B group. The BW appears to become an important predictor as the BW of athletes increases. Additionally, height was the second explanatory variable in the S and B groups, thus suggesting that height needs to be considered for the BMR in these groups. Therefore, the BMR in elite athletes needs to be estimated according to their body composition.

  2. Estimated glomerular filtration rate function in patients with and without metabolic syndrome

    Directory of Open Access Journals (Sweden)

    María E Lizardo

    2016-06-01

    Full Text Available Introduction: Metabolic syndrome (MS is an independent risk factor, which affects the development of chronic kidney disease, so the glomerular filtration rate (GFR as an indicator of glomerular function in patients with and without MS who attended the outpatient clinic “los Grillitos, sector Caña de Azucar”. Materials and Methods: A comparative, correlational, cross-sectional study was conducted in a non-probability sample of convenience consisting of 60 patients with MS diagnosed according to the criteria Panel ATP III, and 60 apparently healthy individuals, whom the GFR was determined by the Cockcroft-Gault as well as clinical and biochemical parameters for the diagnosis of MS. Results: Out of the total patients evaluated, 37 (30.7% showed alterations that put them in grades G2 and G3 system risk stratification of CKD, of these 18 and 19 corresponded to patients with and without MS respectively. Glomerular Hyperfiltration (> 120 mil / min it was found in both groups 28 (46.7% and 24 (40% cases of patients with and without MS respectively. The glomerular function was strongly correlated with abdominal obesity and high levels of stress arterial. As for the number of criteria and its relationship to the level of kidney damage present, not a firm to increase the latter with respect to the first (p=0.385 trend was observed. Conclusion: The change in the glomerular function is not directly related to the MS but with its components, specifically abdominal obesity and hypertension.

  3. Does encephalization correlate with life history or metabolic rate in Carnivora?

    Science.gov (United States)

    Finarelli, John A

    2010-06-23

    A recent analysis of brain size evolution reconstructed the plesiomorphic brain-body size allometry for the mammalian order Carnivora, providing an important reference frame for comparative analyses of encephalization (brain volume scaled to body mass). I performed phylogenetically corrected regressions to remove the effects of body mass, calculating correlations between residual values of encephalization with basal metabolic rate (BMR) and six life-history variables (gestation time, neonatal mass, weaning time, weaning mass, litter size, litters per year). No significant correlations were recovered between encephalization and any life-history variable or BMR, arguing against hypotheses relating encephalization to maternal energetic investment. However, after correcting for clade-specific adaptations, I recovered significant correlations for several variables, and further analysis revealed a conserved carnivoran reproductive strategy, linking degree of encephalization to the well-documented mammalian life-history trade-off between neonatal mass and litter size. This strategy of fewer, larger offspring correlating with increased encephalization remains intact even after independent changes in encephalization allometries in the evolutionary history of this clade.

  4. Temperature dependences of growth rates and carrying capacities of marine bacteria depart from metabolic theoretical predictions.

    Science.gov (United States)

    Huete-Stauffer, Tamara Megan; Arandia-Gorostidi, Nestor; Díaz-Pérez, Laura; Morán, Xosé Anxelu G

    2015-10-01

    Using the metabolic theory of ecology (MTE) framework, we evaluated over a whole annual cycle the monthly responses to temperature of the growth rates (μ) and carrying capacities (K) of heterotrophic bacterioplankton at a temperate coastal site. We used experimental incubations spanning 6ºC with bacterial physiological groups identified by flow cytometry according to membrane integrity (live), nucleic acid content (HNA and LNA) and respiratory activity (CTC+). The temperature dependence of μ at the exponential phase of growth was summarized by the activation energy (E), which was variable (-0.52 to 0.72 eV) but followed a seasonal pattern, only reaching the hypothesized value for aerobic heterotrophs of 0.65 eV during the spring bloom for the most active bacterial groups (live, HNA, CTC+). K (i.e. maximum experimental abundance) peaked at 4 × 10(6) cells mL(-1) and generally covaried with μ but, contrary to MTE predictions, it did not decrease consistently with temperature. In the case of live cells, the responses of μ and K to temperature were positively correlated and related to seasonal changes in substrate availability, indicating that the responses of bacteria to warming are far from homogeneous and poorly explained by MTE at our site. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Effect of copper nanoparticles and copper sulphate on metabolic rate and development of broiler embryos

    DEFF Research Database (Denmark)

    Scott, Abdullah Talal Abudllah; Vadalasetty, Krishna Prasad; Sawosz, E.

    2016-01-01

    Copper (Cu) is regularly used as a growth promoter in poultry production. However, it has been demonstrated that the content of Cu inside eggs might not be sufficient to support the embryonic development. It is possible to supply the embryo with extra nutrients by in-ovo administration. Recently...... consumption — O2 and energy expenditure — EE) and development during embryogenesis. Fertilised broiler eggs were divided into six groups: a non-injected control, a placebo injected with demineralised water, two groups injected, at day one of incubation, with CuSO4 (50 and 100 mg/kg) and two groups injected....../kg Cu-NP and CuSO4 significantly increased O2 consumption and EE on the 16th and 19th day of incubation compared with the control group; Cu-NP had the largest effect on the metabolic rate. However, organ weights (intestine, heart, liver, and breast) relative to the yolk-free body weight were...

  6. Is complex allometry in field metabolic rates of mammals a statistical artifact?

    Science.gov (United States)

    Packard, Gary C

    2017-01-01

    Recent reports indicate that field metabolic rates (FMRs) of mammals conform to a pattern of complex allometry in which the exponent in a simple, two-parameter power equation increases steadily as a dependent function of body mass. The reports were based, however, on indirect analyses performed on logarithmic transformations of the original data. I re-examined values for FMR and body mass for 114 species of mammal by the conventional approach to allometric analysis (to illustrate why the approach is unreliable) and by linear and nonlinear regression on untransformed variables (to illustrate the power and versatility of newer analytical methods). The best of the regression models fitted directly to untransformed observations is a three-parameter power equation with multiplicative, lognormal, heteroscedastic error and an allometric exponent of 0.82. The mean function is a good fit to data in graphical display. The significant intercept in the model may simply have gone undetected in prior analyses because conventional allometry assumes implicitly that the intercept is zero; or the intercept may be a spurious finding resulting from bias introduced by the haphazard sampling that underlies "exploratory" analyses like the one reported here. The aforementioned issues can be resolved only by gathering new data specifically intended to address the question of scaling of FMR with body mass in mammals. However, there is no support for the concept of complex allometry in the relationship between FMR and body size in mammals. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Altered Adipocytokine Levels and Heart Rate Variability in Schizophrenic Patients with Risk of Metabolic Syndrome.

    Science.gov (United States)

    Musa, Zulifeiya; Shabiti, Asikaer; Aizezi, Zainuremu; Yi, Peng

    2016-01-01

    The aim of this study was to investigate changes in the levels of high-sensitivity C-reactive protein (Hs-CRP), tumor necrosis factor α (TNF-α), myocardial fibrosis, and long-term heart rate variability (HRV) in schizophrenic patients at risk of developing metabolic syndrome (MS). 45 subjects without schizophrenia or MS were recruited into the control group (group A), 45 schizophrenic patients not at risk for developing MS constituted group B, and 45 schizophrenic patients at risk of MS constituted group C. Serum levels of TNF-α and Hs-CRP were examined by enzyme linked immunosorbent assay (ELISA). Ultrasonic acoustic densitometry (AD) analysis was performed to assess myocardial fibrosis, and 24 hours dynamic electrocardiography was conducted to determine HRV time-domain index. Compared with the control group, schizophrenic patients at risk of MS displayed a reduced HRV (p 0.05). Moreover, serum levels of TNF-α and Hs-CRP in the schizophrenic patients with MS risk were elevated compared with the control group (p levels, hypertension and obesity, schizophrenic patients at risk of MS exhibited elevated levels of TNF-α and Hs-CRP, enhanced ventricular myocardial fibrosis, and reduced HRV, which might have resulted from structural changes and autonomic nervous dysfunction in cardiac tissues.

  8. A Finished Dietary Supplement Stimulates Lipolysis and Metabolic Rate in Young Men and Women

    Directory of Open Access Journals (Sweden)

    Cameron G. McCarthy

    2012-01-01

    Full Text Available Background Dietary supplements are often marketed to increase lipolysis and thermogenesis, with the proposed end result being weight loss and body fat reduction. It was the purpose of the present investigation to study the acute effects of a weight/fat loss supplement within a sample of healthy human subjects. Methods Twelve subjects (men 24.8 ± 4.3 yrs; women 22.8 ± 0.4 yrs ingested a dietary supplement (OxyELITE Pro™ or a placebo, on two separate days in a double-blind, cross-over design. Blood samples were collected immediately before ingestion, and at 60 and 120 minutes post ingestion, and analyzed for plasma glycerol and free fatty acids (FFA. Breath samples were collected immediately before ingestion and at 30, 60, 90, and 120 minutes post ingestion, for a measure of kilocalorie expenditure using indirect calorimetry. Area under the curve (AUC was calculated. Heart rate and blood pressure were recorded at all times and rate pressure product (RPP was calculated. Results AUC was greater for supplement compared to placebo for glycerol (22.74 ± 1.98 μg · mL -1 · 2 hr -1 vs. 15.76 ± 1.36 μg · mL -1 · 2 hr -1 ; P = 0.001, FFA(1.62 ± 0.07 mmol · L -1 · 2 hr -1 vs. 0.78 ± 0.12 mmol · L -1 · 2 hr -1 ; P < 0.0001, and kilocalorie expenditure (149 ± 7 kcal · 2 hr -1 vs. 122 ± 8 kcal · 2 hr -1 ; P = 0.005. Heart rate ( P = 0.02, systolic blood pressure ( P < 0.0001, and RPP ( P = 0.002 were higher for supplement compared to placebo. Conclusion Ingestion of OxyELITE Pro™ resulted in an increase in blood markers of lipolysis, as well as metabolic rate, during a two-hour post ingestion time period. An increase in hemodynamic variables was also observed. These findings are in reference to a sample of healthy men and women who were naïve to treatment with the dietary supplement. Additional work is needed to determine if the acute changes observed here would persist with chronic use of the supplement and possibly lead to weight

  9. ASSOCIATION BETWEEN HEART RATE VARIABILITY AND COMPONENTS OF THE METABOLIC SYNDROME IN WOMEN WITH RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2014-01-01

    Full Text Available Aim. To study the relationship between heart rate variability (HRV and components of the metabolic syndrome (MS in women with rheumatoid arthritis (RA.Material and methods. Female patients (n=291 with a firm RA diagnosis under 60 years of age were examined. Evaluation of traditional cardiovascular risk factors, MS components (International Diabetes Federation criteria, 24-hour ECG monitoring were performed along with the assessment of clinical symptoms, the degree of activity and severity of RA.Results. Weak associations of HRV with waist circumference, blood pressure level, hypertriglyceridemia, hypoalphalipoproteinemia and smoking were found in the correlation analysis. Patients with RA were divided into three groups depending on the number of existing MS components. Group 1 (0-1 component included 113 women (39%, group 2 (2-3 components – 109 women (37% and group 3 (4-5 components – included 69 women with RA (24%. Progressive decrease in the absolute values and the increase in the percentage of the low values of all the studied time and frequency HRV indices, adjusted by age and heart rate, from the 1st to the 3rd group of women with RA were determined. Significant increase in sympathovagal index from the 1st to the 3rd group was also shown.Conclusion. A combination of several components of the MS in RA plays a greater role in the development of disorders of neurovegetative autonomic control of heart activity (increased influence of the sympathetic and/or reduced influence of the parasympathetic nervous system on cardiac function than each traditional cardiovascular risk factor taken separately. Abnormality in autonomic regulation of cardiac activity may be an important link in the pathogenesis of cardiac arrhythmias, sudden cardiac death and overall cardiovascular mortality in women with RA.

  10. ASSOCIATION BETWEEN HEART RATE VARIABILITY AND COMPONENTS OF THE METABOLIC SYNDROME IN WOMEN WITH RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2015-09-01

    Full Text Available Aim. To study the relationship between heart rate variability (HRV and components of the metabolic syndrome (MS in women with rheumatoid arthritis (RA.Material and methods. Female patients (n=291 with a firm RA diagnosis under 60 years of age were examined. Evaluation of traditional cardiovascular risk factors, MS components (International Diabetes Federation criteria, 24-hour ECG monitoring were performed along with the assessment of clinical symptoms, the degree of activity and severity of RA.Results. Weak associations of HRV with waist circumference, blood pressure level, hypertriglyceridemia, hypoalphalipoproteinemia and smoking were found in the correlation analysis. Patients with RA were divided into three groups depending on the number of existing MS components. Group 1 (0-1 component included 113 women (39%, group 2 (2-3 components – 109 women (37% and group 3 (4-5 components – included 69 women with RA (24%. Progressive decrease in the absolute values and the increase in the percentage of the low values of all the studied time and frequency HRV indices, adjusted by age and heart rate, from the 1st to the 3rd group of women with RA were determined. Significant increase in sympathovagal index from the 1st to the 3rd group was also shown.Conclusion. A combination of several components of the MS in RA plays a greater role in the development of disorders of neurovegetative autonomic control of heart activity (increased influence of the sympathetic and/or reduced influence of the parasympathetic nervous system on cardiac function than each traditional cardiovascular risk factor taken separately. Abnormality in autonomic regulation of cardiac activity may be an important link in the pathogenesis of cardiac arrhythmias, sudden cardiac death and overall cardiovascular mortality in women with RA.

  11. Maximal sum of metabolic exchange fluxes outperforms biomass yield as a predictor of growth rate of microorganisms.

    Science.gov (United States)

    Zarecki, Raphy; Oberhardt, Matthew A; Yizhak, Keren; Wagner, Allon; Shtifman Segal, Ella; Freilich, Shiri; Henry, Christopher S; Gophna, Uri; Ruppin, Eytan

    2014-01-01

    Growth rate has long been considered one of the most valuable phenotypes that can be measured in cells. Aside from being highly accessible and informative in laboratory cultures, maximal growth rate is often a prime determinant of cellular fitness, and predicting phenotypes that underlie fitness is key to both understanding and manipulating life. Despite this, current methods for predicting microbial fitness typically focus on yields [e.g., predictions of biomass yield using GEnome-scale metabolic Models (GEMs)] or notably require many empirical kinetic constants or substrate uptake rates, which render these methods ineffective in cases where fitness derives most directly from growth rate. Here we present a new method for predicting cellular growth rate, termed SUMEX, which does not require any empirical variables apart from a metabolic network (i.e., a GEM) and the growth medium. SUMEX is calculated by maximizing the SUM of molar EXchange fluxes (hence SUMEX) in a genome-scale metabolic model. SUMEX successfully predicts relative microbial growth rates across species, environments, and genetic conditions, outperforming traditional cellular objectives (most notably, the convention assuming biomass maximization). The success of SUMEX suggests that the ability of a cell to catabolize substrates and produce a strong proton gradient enables fast cell growth. Easily applicable heuristics for predicting growth rate, such as what we demonstrate with SUMEX, may contribute to numerous medical and biotechnological goals, ranging from the engineering of faster-growing industrial strains, modeling of mixed ecological communities, and the inhibition of cancer growth.

  12. The effects of temperature and food availability on growth, flexibility in metabolic rates and their relationships in juvenile common carp.

    Science.gov (United States)

    Zeng, Ling-Qing; Fu, Cheng; Fu, Shi-Jian

    2018-03-01

    Flexibility in phenotypic traits can allow organisms to handle environmental changes. However, the ecological consequences of flexibility in metabolic rates are poorly understood. Here, we investigated whether the links between growth and flexibility in metabolic rates vary between two temperatures. Common carp Cyprinus carpio were raised in three temperature treatments [the 18°C, 28°C and 28°C-food control (28°C-FC)] and fed to satiation of receiving food either once or twice daily for 4weeks. The morphology and metabolic rates (standard metabolic rate, SMR; maximum metabolic rate, MMR) were measured at the beginning and end of the experiment. The mean total food ingested by fish in the 28°C-FC treatment was the same as that by fish in the 18°C treatment at each food availability. The final SMR (not MMR and aerobic scope, AS=MMR-SMR) increased more in the 28°C and 28°C-FC treatments with twice-daily feedings than once-daily feedings. Fish in the 28°C treatment had a higher specific growth rate (SGR) than fish in the 28°C-FC and 18°C treatments at both food availabilities. However, no differences in feeding efficiency (FE) were found among the three treatments in fish fed twice daily. The flexibility in SMR was related to individual differences in SGR, not with food intake and FE; individuals who increased their SMR more had a smaller growth performance with twice-daily feedings at 28°C, but it did not exist at 18°C. Flexibility in SMR provides a growth advantage in juvenile common carp experiencing changes in food availability and this link is temperature-dependent. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The postabsorptive and postprandial metabolic rates of praying mantises: Comparisons across species, body masses, and meal sizes.

    Science.gov (United States)

    McCue, Marshall D; Salinas, Isabella; Ramirez, Gabriella; Wilder, Shawn

    The metabolic rate of an animal affects the amount of energy available for its growth, activity and reproduction and, ultimately, shapes how energy and nutrients flow through ecosystems. Standard metabolic rate (SMR; when animals are post-absorptive and at rest) and specific dynamic action (SDA; the cost of digesting and processing food) are two major components of animal metabolism. SMR has been studied in hundreds of species of insects, but very little is known about the SMR of praying mantises. We measured the rates of CO 2 production as a proxy for metabolic rate and tested the prediction that the SMR of mantises more closely resembles the low SMR of spiders - a characteristic generally believed to be related to their sit-and-wait foraging strategy. Although few studies have examined SDA in insects we also tested the prediction that mantises would exhibit comparatively large SDA responses characteristic of other types of predators (e.g., snakes) known to consume enormous, protein-rich meals. The SMR of the mantises was positively correlated with body mass and did not differ among the four species we examined. Their SMR was best described by the equation μW=1526*g 0.745 and was not significantly different from that predicted by the standard 'insect-curve'; but it was significantly higher than that of spiders to which mantises are ecologically more similar than other insects. Mantises consumed meals as large as 138% of their body mass and within 6-12h of feeding and their metabolic rates doubled before gradually returning to prefeeding rates over the subsequent four days. We found that the SDA responses were isometrically correlated with meal size and the relative cost of digestion was 38% of the energy in each meal. We conclude that mantises provide a promising model to investigate nutritional physiology of insect predators as well as nutrient cycling within their ecological communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Molecular and metabolic adaptations of Lactococcus lactis at near-zero growth rates

    NARCIS (Netherlands)

    Ercan, O.; Wels, M.; Smid, E.J.; Kleerebezem, M.

    2015-01-01

    This paper describes the molecular and metabolic adaptations of Lactococcus lactis during the transition from a growing to a near-zero growth state using carbon-limited retentostat cultivation. Transcriptomic analyses revealed that metabolic patterns shifted between lactic- and mixed-acid

  15. Molecular and metabolic adaptations of Lactococcus lactis at near-zero growth rates

    NARCIS (Netherlands)

    Ercan, O.; Wels, M.W.; Smid, E.J.; Kleerebezem, M

    2015-01-01

    This paper describes the molecular and metabolic adaptations of Lactococcus lactis during the transition from a growing to a near-zero growth state by using carbon-limited retentostat cultivation. Transcriptomic analyses revealed that metabolic patterns shifted between lactic- and mixed-acid

  16. Molecular and Metabolic Adaptations of Lactococcus lactis at Near-Zero Growth Rates

    NARCIS (Netherlands)

    Ercan, O.; Wels, M.; Smid, E.J.; Kleerebezem, M.

    2015-01-01

    This paper describes the molecular and metabolic adaptations of Lactococcus lactis during the transition from a growing to a near-zero growth state by using carbon-limited retentostat cultivation. Transcriptomic analyses revealed that metabolic patterns shifted between lactic- and mixed-acid

  17. The Coupling of Cerebral Metabolic Rate of Glucose and Cerebral Blood Flow In Vivo

    DEFF Research Database (Denmark)

    Hasselbalch, Steen; Paulson, Olaf Bjarne

    2012-01-01

    and metabolism was originally performed using the Kety-Schmidt method and this method still represent the gold standard by which subsequent methods have been evaluated. However, in its classical setting, the method overestimates cerebral blood flow. Studies of metabolic changes during activation must take......The energy supplied to the brain by metabolic substrate is largely utilized for maintaining synaptic transmission. In this regulation cerebral blood flow and glucose consumption is tightly coupled as well in the resting condition as during activation. Quantification of cerebral blood flow...... this into account, and subsequent methods for measurement of regional glucose metabolism must be corrected accordingly in order to allow reliable quantitative comparisons of metabolite changes in activation studies. For studies of regional metabolic changes during activation quantification poses further...

  18. Flexibility in basal metabolic rate and evaporative water loss among hoopoe larks exposed to different environmental temperatures

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI

    2000-01-01

    The 'energy demand' hypothesis for short-term adjustments in basal metabolic rate (BMR) posits that birds adjust the size of their internal organs relative to food intake, a correlate of energy demand, We tested this hypothesis on hoopoe larks (Alaemon alaudipes), inhabitants of the Arabian desert,

  19. Gender dependent rate of metabolism of the opioid receptor-PET ligand [{sup 18}F]fluoroethyl-diprenorphine

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, G.; Spilker, M.E.; Hauser, A.I.; Boecker, H.; Schwaiger, M.; Wester, H.J. [Technische Univ. Muenchen, Garching (Germany). Dept. of Nuclear Medicine; Sprenger, T.; Platzer, S.; Toelle, T.R. [Technische Univ. Muenchen, Garching (Germany). Klinikum rechts der Isar, Neurology

    2006-07-01

    Aim: The morphinane-derivate 6-O-(2-[{sup 18}F]fluoroethyl)-6-O-desmethyldiprenorphine ([{sup 18}F]FDPN) is a non-selective opioid receptor ligand currently used in positron emission tomography (PET). Correction for plasma metabolites of the arterial input function is necessary for quantitative measurements of [{sup 18}]FDPN binding. A study was undertaken to investigate if there are gender dependent differences in the rate of metabolism of [{sup 18}F]FDPN. Methods: The rate of metabolism of [{sup 18}F]FDPN was mathematically quantified by fitting a bi-exponential function to each individual's dynamic metabolite data. Results: No statistically significant gender differences were found for age, weight, body mass index or dose. However, significant differences (p<0.01) in two of the four kinetic parameters describing the rate of metabolism were found between the two groups, with women metabolizing [{sup 18}F]FDPN faster than men. These differences were found in the contribution of the fast and slow kinetic components of the model describing the distribution of radioactive species in plasma, indicating a higher rate of enzyme-dependent degradation of [{sup 18}F]FDPN in women than in men. Conclusion: The findings reinforce the need for individualized metabolite correction during [{sup 18}F]FDPN-PET scans and also indicate that in certain cases, grouping according to gender could be performed in order to minimize methodological errors of the input function prior to kinetic analyses. (orig.)

  20. Excess heart rate and systolic blood pressure during psychological stress in relation to metabolic demand in adolescents

    Science.gov (United States)

    Cardiovascular responses during exercise are matched to the increased metabolic demand, but this may not be the case during psychological stress. No studies to date have tested this hypothesis in youth. Fifty-four youth, ages 13-16 years completed two visits. Heart rate (HR), systolic blood pressu...

  1. Intraspecific Allometry of Basal Metabolic Rate : Relations with Body Size, Temperature, Composition, and Circadian Phase in the Kestrel, Falco tinnunculus

    NARCIS (Netherlands)

    Daan, Serge; Masman, Dirkjan; Strijkstra, Arjen; Verhulst, Simon

    1989-01-01

    The relationship between body size and basal metabolic rate (BMR) in homeotherms has been treated in the literature primarily by comparison between species of mammals or birds. This paper focuses on the intraindividual changes in BMR when body mass (W) varies with different maintenance regimens. BMR

  2. Monitoring and prevalence rates of metabolic syndrome in military veterans with serious mental illness.

    Directory of Open Access Journals (Sweden)

    Sameed Ahmed M Khatana

    Full Text Available BACKGROUND: Cardiovascular disease is the leading cause of mortality among patients with serious mental illness (SMI and the prevalence of metabolic syndrome--a constellation of cardiovascular risk factors--is significantly higher in these patients than in the general population. Metabolic monitoring among patients using second generation antipsychotics (SGAs--a risk factor for metabolic syndrome--has been shown to be inadequate despite the release of several guidelines. However, patients with SMI have several factors independent of medication use that predispose them to a higher prevalence of metabolic syndrome. Our study therefore examines monitoring and prevalence of metabolic syndrome in patients with SMI, including those not using SGAs. METHODS AND FINDINGS: We retrospectively identified all patients treated at a Veterans Affairs Medical Center with diagnoses of schizophrenia, schizoaffective disorder or bipolar disorder during 2005-2006 and obtained demographic and clinical data. Incomplete monitoring of metabolic syndrome was defined as being unable to determine the status of at least one of the syndrome components. Of the 1,401 patients included (bipolar disorder: 822; schizophrenia: 222; and schizoaffective disorder: 357, 21.4% were incompletely monitored. Only 54.8% of patients who were not prescribed SGAs and did not have previous diagnoses of hypertension or hypercholesterolemia were monitored for all metabolic syndrome components compared to 92.4% of patients who had all three of these characteristics. Among patients monitored for metabolic syndrome completely, age-adjusted prevalence of the syndrome was 48.4%, with no significant difference between the three psychiatric groups. CONCLUSIONS: Only one half of patients with SMI not using SGAs or previously diagnosed with hypertension and hypercholesterolemia were completely monitored for metabolic syndrome components compared to greater than 90% of those with these characteristics

  3. Physiological underpinnings associated with differences in pace of life and metabolic rate in north temperate and neotropical birds.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Cooper-Mullin, Clara; Calhoon, Elisabeth A; Williams, Joseph B

    2014-07-01

    Animal life-history traits fall within limited ecological space with animals that have high reproductive rates having short lives, a continuum referred to as a "slow-fast" life-history axis. Animals of the same body mass at the slow end of the life-history continuum are characterized by low annual reproductive output and low mortality rate, such as is found in many tropical birds, whereas at the fast end, rates of reproduction and mortality are high, as in temperate birds. These differences in life-history traits are thought to result from trade-offs between investment in reproduction or self-maintenance as mediated by the biotic and abiotic environment. Thus, tropical and temperate birds provide a unique system to examine physiological consequences of life-history trade-offs at opposing ends of the "pace of life" spectrum. We have explored the implications of these trade-offs at several levels of physiological organization including whole-animal, organ systems, and cells. Tropical birds tend to have higher survival, slower growth, lower rates of whole-animal basal metabolic rate and peak metabolic rate, and smaller metabolically active organs compared with temperate birds. At the cellular level, primary dermal fibroblasts from tropical birds tend to have lower cellular metabolic rates and appear to be more resistant to oxidative cell stress than those of temperate birds. However, at the subcellular level, lipid peroxidation rates, a measure of the ability of lipid molecules within the cell membranes to thwart the propagation of oxidative damage, appear not to be different between tropical and temperate species. Nevertheless, lipids in mitochondrial membranes of tropical birds tend to have increased concentrations of plasmalogens (phospholipids with antioxidant properties), and decreased concentrations of cardiolipin (a complex phospholipid in the electron transport chain) compared with temperate birds.

  4. Bile acid metabolism in hereditary forms of hypertriglyceridemia: evidence for an increased synthesis rate in monogenic familial hypertriglyceridemia.

    OpenAIRE

    Angelin, B; Hershon, K S; Brunzell, J D

    1987-01-01

    This study was undertaken to characterize bile acid metabolism in hereditary forms of hypertriglyceridemia. Ten hypertriglyceridemic patients (type IV phenotype) with familial combined hyperlipidemia and 7 patients with monogenic familial hypertriglyceridemia (FHTG) were compared with 18 healthy controls; all subjects were males. Pool size, synthesis rate, and fractional catabolic rate of cholic and chenodeoxycholic acids were determined with an isotope dilution technique. Patients with FHTG ...

  5. Eucalanoid copepod metabolic rates in the oxygen minimum zone of the eastern tropical north Pacific: Effects of oxygen and temperature

    Science.gov (United States)

    Cass, Christine J.; Daly, Kendra L.

    2014-12-01

    The eastern tropical north Pacific Ocean (ETNP) contains one of the world's most severe oxygen minimum zones (OMZs), where oxygen concentrations are less than 2 μmol kg-1. OMZs cause habitat compression, whereby species intolerant of low oxygen are restricted to near-surface oxygenated waters. Copepods belonging to the family Eucalanidae are dominant zooplankters in this region and inhabit a variety of vertical habitats within the OMZ. The purpose of this study was to compare the metabolic responses of three species of eucalanoid copepods, Eucalanus inermis, Rhincalanus rostrifrons, and Subeucalanus subtenuis, to changes in temperature and environmental oxygen concentrations. Oxygen consumption and urea, ammonium, and phosphate excretion rates were measured via end-point experiments at three temperatures (10, 17, and 23 °C) and two oxygen concentrations (100% and 15% air saturation). S. subtenuis, which occurred primarily in the upper 50 m of the water column at our study site, inhabiting well-oxygenated to upper oxycline conditions, had the highest metabolic rates per unit weight, while E. inermis, which was found throughout the water column to about 600 m depth in low oxygen waters, typically had the lowest metabolic rates. Rates for R. rostrifrons (found primarily between 200 and 300 m depth) were intermediate between the other two species and more variable. Metabolic ratios suggested that R. rostrifrons relied more heavily on lipids to fuel metabolism than the other two species. S. subtenuis was the only species that demonstrated a decrease in oxygen consumption rates (at intermediate 17 °C temperature treatment) when environmental oxygen concentrations were lowered. The percentage of total measured nitrogen excreted as urea (% urea-N), as well as overall urea excretion rates, responded in a complex manner to changes in temperature and oxygen concentration. R. rostrifrons and E. inermis excreted a significantly higher % of urea-N in low oxygen treatments at

  6. Identical metabolic rate and thermal conductance in Rock Sandpiper (Calidris ptilocnemis) subspecies with contrasting nonbreeding life histories

    Science.gov (United States)

    Ruthrauff, Daniel R.; Dekinga, Anne; Gill, Robert E.; Piersma, Theunis

    2013-01-01

    Closely related species or subspecies can exhibit metabolic differences that reflect site-specific environmental conditions. Whether such differences represent fixed traits or flexible adjustments to local conditions, however, is difficult to predict across taxa. The nominate race of Rock Sandpiper (Calidris ptilocnemis) exhibits the most northerly nonbreeding distribution of any shorebird in the North Pacific, being common during winter in cold, dark locations as far north as upper Cook Inlet, Alaska (61°N). By contrast, the tschuktschorum subspecies migrates to sites ranging from about 59°N to more benign locations as far south as ~37°N. These distributional extremes exert contrasting energetic demands, and we measured common metabolic parameters in the two subspecies held under identical laboratory conditions to determine whether differences in these parameters are reflected by their nonbreeding life histories. Basal metabolic rate and thermal conductance did not differ between subspecies, and the subspecies had a similar metabolic response to temperatures below their thermoneutral zone. Relatively low thermal conductance values may, however, reflect intrinsic metabolic adaptations to northerly latitudes. In the absence of differences in basic metabolic parameters, the two subspecies’ nonbreeding distributions will likely be more strongly influenced by adaptations to regional variation in ecological factors such as prey density, prey quality, and foraging habitat.

  7. Variation in Metabolic Rate among Individuals Is Related to Tissue-Specific Differences in Mitochondrial Leak Respiration.

    Science.gov (United States)

    Salin, Karine; Auer, Sonya K; Rudolf, Agata M; Anderson, Graeme J; Selman, Colin; Metcalfe, Neil B

    Standard metabolic rate (SMR) and maximum metabolic rate (MMR) typically vary two- or threefold among conspecifics, with both traits assumed to significantly impact fitness. However, the underlying mechanisms that determine such intraspecific variation are not well understood. We examined the influence of mitochondrial properties on intraspecific variation in SMR and MMR and hypothesized that if SMR supports the cost of maintaining the metabolic machinery required for MMR, then the mitochondrial properties underlying these traits should be shared. Mitochondrial respiratory capacity (leak and phosphorylating respiration) and mitochondrial content (cytochrome c oxidase activity) were determined in the liver and white muscle of brown trout Salmo trutta of similar age and maintenance conditions. SMR and MMR were uncorrelated across individuals and were not associated with the same mitochondrial properties, suggesting that they are under the control of separate physiological processes. Moreover, tissue-specific relationships between mitochondrial properties and whole-organism metabolic traits were observed. Specifically, SMR was positively associated with leak respiration in liver mitochondria, while MMR was positively associated with muscle mitochondrial leak respiration and mitochondrial content. These results suggest that a high SMR or MMR, rather than signaling a higher ability for respiration-driven ATP synthesis, may actually reflect greater dissipation of energy, driven by proton leak across the mitochondrial inner membrane. Knowledge of these links should aid interpretation of the potential fitness consequences of such variation in metabolism, given the importance of mitochondria in the utilization of resources and their allocation to performance.

  8. Low metabolism and inactive lifestyle of a tropical rain forest bird investigated via heart-rate telemetry.

    Science.gov (United States)

    Steiger, Silke S; Kelley, J Patrick; Cochran, William W; Wikelski, Martin

    2009-01-01

    Birds in the lowland tropical rain forest are expected to have low energy turnover. Here, we used heart rate telemetry to estimate nighttime resting metabolic rate (RMR), daily energy expenditure (DEE), and locomotor activity of a small, long-lived tropical rain forest-understory bird, the spotted antbird (Hylophylax naevioides). Heart rate was linearly related to oxygen consumption in respirometry measurements that encompassed 96% of heart rates measured in wild birds. Heart rates in the wild ranged from 260 beats/min at night to 824 beats/min during the day, with a mean of 492 beats/min. Compared with temperate-forest birds of similar body mass, wild spotted antbirds had a low DEE, only 51% of the expected value. Such low metabolism was achieved mainly by being locomotively inactive for 35% of the daytime (i.e., 0 hops or flights/min). On average, spotted antbirds exhibited 1.6 hops or short flights/min during the daytime. In addition, they decreased nighttime RMR in the wild (at ambient temperatures below their thermoneutral zone [TNZ]) to levels equivalent to nighttime RMR in the laboratory at temperatures within their TNZ. This suggests that wild birds reduce their body temperature every night. Our data confirm and extend previous studies showing that tropical passerines have low metabolic rates.

  9. Sustainable systems rating program: Marketing Green'' Building in Austin, Texas

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    Four major resource issues for home construction were identified: water, energy, materials, and waste. A systems flow model was then developed that tracked the resource issues through interactive matrices in the areas of sourcing, processing, using, and disposing or recycling. This model served as the basis for a rating system used in an educational and marketing tool called the Eco-Home Guide.

  10. Effects of photoperiod on food intake, activity and metabolic rate in adult neutered male cats.

    Science.gov (United States)

    Kappen, K L; Garner, L M; Kerr, K R; Swanson, K S

    2014-10-01

    With the continued rise in feline obesity, novel weight management strategies are needed. To date, strategies aimed at altering physical activity, an important factor in weight maintenance, have been lacking. Photoperiod is known to cause physiological changes in seasonal mammals, including changes in body weight (BW) and reproductive status. Thus, our objective was to determine the effect of increased photoperiod (longer days) on voluntary physical activity levels, resting metabolic rate (RMR), food intake required to maintain BW, and fasting serum leptin and ghrelin concentrations in adult cats. Eleven healthy, adult, neutered, male domestic shorthair cats were used in a randomized crossover design study. During two 12-week periods, cats were exposed to either a short-day (SD) photoperiod of 8 h light: 16 h dark or a long-day (LD) photoperiod of 16 h light: 8 h dark. Cats were fed a commercial diet to maintain baseline BW. In addition to daily food intake and twice-weekly BW, RMR (via indirect calorimetry), body composition [via dual-energy X-ray absorptiometry (DEXA)] and physical activity (via Actical activity monitors) were measured at week 0 and 12 of each period. Fasting serum leptin and ghrelin concentrations were measured at week 0, 6 and 12 of each period. Average hourly physical activity was greater (p = 0.008) in LD vs. SD cats (3770 vs. 3129 activity counts/h), which was primarily due to increased (p cats (9.02 vs. 8.37 kcal/h). Body composition, serum leptin and serum ghrelin were not altered by photoperiod. More research is needed to determine potential mechanisms by which these physiological changes occurred and how they may apply to weight management strategies.

  11. The effect of smoking two cigarettes on resting metabolic rate with and without food.

    Science.gov (United States)

    Warwick, P M; Chapple, R S; Thomson, E S

    1987-01-01

    Resting metabolic rate (RMR) was measured using a ventilated hood apparatus in 15 subjects before (BMR) and for 5 h after (5HEE) four treatments. In 10 smokers (five occasional and five habitual) the treatments were: food (600 kcal (2.51 MJ) breakfast) with and without smoking two cigarettes (F +/- S) and no food with and without smoking (NF +/- S). In five non-smokers duplicate measurements of food (F-S) and no food (NF-S) were made. In non-smokers the thermic effect of food (TEF) averaged 9.35 per cent of the ingested energy. Duplicate measures of 5HEE showed good reproducibility both with and without food (c.v. 2.5 and 1.3 per cent respectively). In smokers, RMR did not increase after smoking even during the first 15-30 min. There were no apparent differences in response between occasional and habitual smokers. 5HEE and delta 5HEE (5HEE minus BMR) were significantly lower after food with smoking than without smoking (-16 kcal (67 kJ)/5 h, P less than 0.001 and -14 kcal (59 kJ)/5 h, P less than 0.02 respectively) but not significantly lower after smoking without food. TEF was lower with smoking (8.6 per cent of ingested energy) than without smoking (10.0 per cent of ingested energy) but the difference was not significant (P = 0.23). TEF in smokers regardless of treatment averaged 9.3 per cent of the ingested energy. We conclude that any effects of smoking two cigarettes in isolation after overnight deprivation are too small or too variable to consistently influence RMR or the thermic effect of food.

  12. Resting metabolic rate and thermogenic effect of food in vegetarian diets compared with Mediterranean diets.

    Science.gov (United States)

    Bissoli, L; Armellini, F; Zamboni, M; Mandragona, R; Ballarin, A; Bosello, O

    1999-01-01

    The purpose of our work is to compare the resting metabolic rate (RMR) and thermogenic effect of food (TEF) in a group of vegetarians and a group of subjects consuming a Mediterranean diet. The composition of the diets was similar. Thirty-two subjects were studied: 16 vegetarians (age 34 +/- 9 years, BMI 21 +/- 2) and 16 omnivors (age 30 +/- 5 years, BMI 22 +/- 3). All were in excellent general health. Each subject consumed a dish of pasta (100 g) and bread (30 g) after RMR had been measured. TEF was measured over the next 3 h and calculated as the incremental area above RMR. Energy (vegetarians and omnivors 7,727 +/- 3,516 vs 8,970 +/- 2,273 kJ/day, respectively) and carbohydrate (vegetarians and omnivors 285.1 +/- 141.3 vs. 300.1 +/- 74 g/day, respectively) intakes of the 2 groups were similar. The vegetarian group consumed a higher quantity of fiber (30.5 +/- 16.7 vs. 16.5 +/- 7.9) and a lower amount of protein (44.9 +/- 18.3 vs. 70.1 +/- 14.9) than the omnivorous group. No significant differences were observed in RMR (4.23 +/- 0.96 vs. 4.06 +/- 0.54 kJ/min) and TEF (0.50 +/- 0.25 vs. 0.38 +/- 0.25 Delta kJ/min) between the groups. Results did not change after correcting for weight, age and gender. Our study failed to show any significant differences in RMR and TEF between vegetarians and subjects consuming a Mediterranean diet. We conclude that vegetarianism per se is not accompanied by a difference in RMR and TEF when the carbohydrate content of the diet is similar to a control group of nonvegetarians.

  13. Intrinsic and extrinsic influences on standard metabolic rates of three species of Australian otariid.

    Science.gov (United States)

    Ladds, Monique A; Slip, David J; Harcourt, Robert G

    2017-01-01

    The study of marine mammal energetics can shed light on how these animals might adapt to changing environments. Their physiological potential to adapt will be influenced by extrinsic factors, such as temperature, and by intrinsic factors, such as sex and reproduction. We measured the standard metabolic rate (SMR) of males and females of three Australian otariid species (two Australian fur seals, three New Zealand fur seals and seven Australian sea lions). Mean SMR ranged from 0.47 to 1.05 l O 2 min -1 , which when adjusted for mass was from 5.33 to 7.44 ml O 2 min -1 kg -1 . We found that Australian sea lion mass-specific SMR (sSMR; in millilitres of oxygen per minute per kilogram) varied little in response to time of year or moult, but was significantly influenced by sex and water temperature. Likewise, sSMR of Australian and New Zealand fur seals was also influenced by sex and water temperature, but also by time of year (pre-moult, moult or post-moult). During the moult, fur seals had significantly higher sSMR than at other times of the year, whereas there was no discernible effect of moult for sea lions. For both groups, females had higher sSMR than males, but sea lions and fur seals showed different responses to changes in water temperature. The sSMR of fur seals increased with increasing water temperature, whereas sSMR of sea lions decreased with increasing water temperature. There were no species differences when comparing animals of the same sex. Our study suggests that fur seals have more flexibility in their physiology than sea lions, perhaps implying that they will be more resilient in a changing environment.

  14. The impact of short-term depot-medroxyprogesterone acetate treatment on resting metabolic rate.

    Science.gov (United States)

    Steward, Ryan G; Bateman, Lori A; Slentz, Cris; Stanczyk, Frank Z; Price, Thomas M

    2016-04-01

    This study examines the effect of a progestogen (depot-medroxyprogesterone acetate, DMPA) on resting metabolic rate (RMR) in a cohort of young, normal-weight healthy women. We hypothesize an increase in RMR and nonshivering thermogenesis (NST) resulting in increased body temperature by DMPA. We performed a prospective cohort study in 13 subjects tested at baseline, 3 weeks and 9 weeks after 150 mg intramuscular DMPA administration. RMR was determined with indirect calorimetry. Secondary endpoints included changes in body mass index (BMI), body composition, temperature and serum levels of estradiol (E2), luteinizing hormone (LH), progesterone and MPA. The percent change in RMR from baseline to week 3 (9%) was significantly higher than the percent change from baseline to week 9 (1.6%) (p=.045). The greatest percent change from baseline to week 3 compared to baseline to week 9 was seen in women initiating DMPA in the luteal phase of the cycle. Hypothalamic-pituitary-ovarian axis was evident by decreases in E2, LH and progesterone. DMPA resulted in increased body temperature with a significant correlation between the change in body temperature and the change in RMR. No change in body composition was seen. RMR and NST increased in young healthy women with normal BMI 3 weeks after receiving the initial dose of 150 mg DMPA for contraception. The effect was augmented when the drug was administered during the luteal phase of the menstrual cycle. DMPA increases RMR and thermogenesis independent of changes in body mass. An increase in weight with chronic DMPA may result from a combination of hyperphagia and abnormal NST in predisposed individuals. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Cerebral metabolic rate of oxygen (CMRO2 ) mapping with hyperventilation challenge using quantitative susceptibility mapping (QSM).

    Science.gov (United States)

    Zhang, Jingwei; Zhou, Dong; Nguyen, Thanh D; Spincemaille, Pascal; Gupta, Ajay; Wang, Yi

    2017-05-01

    Our objective was to demonstrate the feasibility of using hyperventilation as an efficient vasoconstrictive challenge and prior knowledge as denoising constraints for cerebral metabolic rate of oxygen (CMRO2 ) mapping based upon quantitative susceptibility mapping (QSM). Three-dimensional (3D) multi-echo gradient echo and arterial spin labeling imaging were performed to calculate QSM and perfusion maps before and after a hyperventilation challenge in 11 healthy subjects. For comparison, this was repeated using a caffeine challenge. Whole-brain CMRO2 and oxygen extraction fraction (OEF) maps were computed using constrained optimization. Hyperventilation scans were repeated to measure reproducibility. Regional agreement of CMRO2 and OEF maps was analyzed within the cortical gray matter (CGM) using t-test and Bland-Altman plots. Hyperventilation challenge eliminates the 30-min waiting time needed for caffeine to exert its vasoconstrictive effects. Mean CMRO2 (in µmol/100g/min) obtained in CGM using the caffeine and repeated hyperventilation scans were 149 ± 16, 153 ± 19, and 150 ± 20, respectively. This corresponded to an OEF of 33.6 ± 3.4%, 32.3 ± 3.2%, and 34.1 ± 3.8% at baseline state and 39.8 ± 4.8%, 43.6 ± 6.2%, and 42.8 ± 6.8% at challenged state, respectively. Hyperventilation scans produced a good agreement of CMRO2 and OEF values. Hyperventilation is a feasible, reproducible, and efficient vasoconstrictive challenge for QSM-based quantitative CMRO2 mapping. Magn Reson Med 77:1762-1773, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  16. Metabolic and Hormonal Determinants of Glomerular Filtration Rate and Renal Hemodynamics in Severely Obese Individuals

    Directory of Open Access Journals (Sweden)

    Edoardo Vitolo

    2016-10-01

    Full Text Available Objective: Renal function is often compromised in severe obesity. A true measurement of glomerular filtration rate (GFR is unusual, and how estimation formulae (EstForm perform in such individuals is unclear. We characterized renal function and hemodynamics in severely obese individuals, assessing the reliability of EstForm. Methods: We measured GFR (mGFR by iohexol plasma clearance, renal plasma flow (RPF by 123I-ortho-iodo-hippurate, basal and stimulated vascular renal indices, endothelium-dependent and -independent vasodilation using flow-mediated dilation (FMD as well as metabolic and hormonal profile in morbid, otherwise healthy, obese subjects. Results: Compared with mGFR, the better performing EstForm was CKD-EPI (5.3 ml/min/1.73 m2 bias by Bland-Altman analysis. mGFR was directly related with RPF, total and incremental glucose AUC, and inversely with PTH and h8 cortisol. Patients with mGFR below the median shown significantly higher PTH and lower vitamin D3. Basal or dynamic renal resistive index, FMD, pulse wave velocity were not related with mGFR. In an adjusted regression model, renal diameter and plasma flow remained related with mGFR (R2 = 0.67, accounting for 15% and 21% of mGFR variance, respectively. Conclusions: CKD-EPI formula should be preferred in morbid obesity; glucose increments during oral glucose tolerance test correlate with hyperfiltration; RPF and diameter are independent determinants of mGFR; slightly high PTH values, frequent in obesity, might influence mGFR.

  17. [Longitudinal changes in body composition and basal metabolic rate in institutionalized or domiciled obese adolescents].

    Science.gov (United States)

    Lazzer, S; Meyer, M; Derumeaux, H; Boirie, Y; Vermorel, M

    2005-09-01

    The prevalence of obesity in children has increased dramatically during the past decades, and requires efficient care. To determine changes in anthropometric parameters and basal metabolic rate (BMR) in obese adolescents during and after 2 types of weight-reduction programs. Twenty-six adolescents (group I, Z-score of BMI = 4.72) followed a 9-month-weight reduction program including a moderate energy restriction and regular physical activities in a specialized institution. In addition, 39 adolescents (group E, Z-score of BMI = 2.83) followed at home a 9-month-weight reduction program including medical and dietetic advices. Body composition (by impedancemetry) and BMR (by indirect calorimetry) were assessed before the beginning (M0), 4 months after (M4) and at the end (M9) of the programs, then 4 months (M13) and 16 month (M25) after the end of the weight-reduction programs. Twenty-two adolescents in group I and 20 adolescents in group E completed the study. At M0, age, body weight (BW), fat-free mass (FFM) and BMR of subjects of group I were higher (1.0 year, 36 %, 30 % and 23 %, respectively, P adolescents of group I showed significant reductions in BW and FM (-19 and -37 %, respectively, P adolescents, but increased (+9.7% and 14.8%, respectively, P adolescents. However, BMR did not change significantly in all adolescents. Between M13 and M25, BW, FM, FFM and BMR increased significantly (+13%, +34%, +6% et +5%, respectively, P adolescents of group E showed significant increases in BW, FFM and BMR (+8%, +14% and +10%, respectively, P program at the institution could contribute to body weight regain in the post-obese adolescents if they do not maintain the lifestyle habits taught during the weight-reduction period. In other respects, Z-score was stabilized in 51% of domiciled obese adolescents.

  18. Does exercise training affect resting metabolic rate in adolescents with obesity?

    Science.gov (United States)

    Alberga, Angela S; Prud'homme, Denis; Sigal, Ronald J; Goldfield, Gary S; Hadjiyannakis, Stasia; Gougeon, Réjeanne; Phillips, Penny; Malcolm, Janine; Wells, George A; Doucette, Steve; Ma, Jinhui; Kenny, Glen P

    2017-01-01

    We evaluated the hypothesis that resistance exercise training performed alone or in combination with aerobic exercise training would increase resting metabolic rate (RMR) relative to aerobic-only and nonexercising control groups. Postpubertal adolescents (N = 304) aged 14-18 years with obesity (body mass index (BMI) ≥ 95th percentile) or overweight (BMI ≥ 85th percentile + additional diabetes risk factor(s)) were randomized to 4 groups for 22 weeks: Aerobic exercise training, Resistance exercise training, Combined aerobic and resistance exercise training, or Control. All participants received dietary counselling targeting a daily energy deficit of 250 kcal. RMR was measured by indirect calorimetry and body composition by magnetic resonance imaging. There was no significant change in RMR in any group, in spite of significant within-group increases in fat-free mass in the Aerobic, Resistance, and Combined exercise training groups. RMR at baseline and 6 months were Aerobic: 1972 ± 38 and 1990 ± 41; Resistance: 2024 ± 37 and 1992 ± 41; Combined: 2023 ± 38 and 1995 ± 38; Control: 2075 ± 38 and 2073 ± 39 kcal/day (p > 0.05). There were no between-group differences in RMR after adjustment for total body weight or fat-free mass between groups over time. Per-protocol analyses including only participants with ≥70% adherence, and analyses stratified by sex, also showed no within- or between-group differences in RMR. In conclusion, despite an increase in fat-free mass in all exercise groups, 6 months of aerobic, resistance, or combined training with modest dietary restriction did not increase RMR compared with diet only in adolescents with obesity.

  19. Basal metabolic rate, maximum thermogenic capacity and aerobic scope in rodents: interaction between environmental temperature and torpor use

    OpenAIRE

    Careau, Vincent

    2013-01-01

    When torpid animals arouse and warm up to restore normal body temperature (Tb), they produce heat at levels that can reach up to 10 times basal metabolic rate (BMR), close to the cold-induced summit metabolism (VO2-sum). Because torpor is an adaptation aimed at conserving energy over periods of low ambient temperature (Ta) and food availability, selective forces that have led to the evolution of torpor may have simultaneously favoured high thermogenic capacity (i.e. VO2-sum) relative to the m...

  20. Post exercise basil metabolic rate following a 6 minute high intensity interval workout

    National Research Council Canada - National Science Library

    Petrofsky, Jerrold; Laymon, Michael; Altenbernt, Lorna; Buffum, Alyx; Gonzales, Kristine; Guinto, Chez

    2011-01-01

    Recent evidence shows that a burst of rapid exercise with a duration of 10 minutes or less may be more effective in increasing body metabolism in the hours after exercise than is seen with low level aerobic exercise...

  1. Mobilising sustainable local government revenue in Ghana: modelling property rates and business taxes

    Directory of Open Access Journals (Sweden)

    Samuel B Biitir

    2015-06-01

    Full Text Available Property rates and business operating license fees constitute the major revenue sources for local government authorities. Accurate assessment of these revenues enhances the revenue base and effectiveness of their generation. Assessment of property rates and business operating license fees have been identified as one of the limiting factors that inhibit the revenue potential of local government authorities. Assessment must obey the principles of taxation such as efficiency, equity and fairness, adequacy, administrative feasibility and political acceptability. Over the years, the Sekondi-Takoradi Metropolitan Assembly (STMA acknowledges that, it has had problems in ensuring equity and fairness in the assessment of property rates and business operating license fees. The paper reports on a computer modelling study carried out to introduce measure to ensure equity and fairness in assessing tax objects. A computer application has been developed with quantitative measures to evaluate and assess equity in tax assessment. A test run of the system has been successful and a pilot test is currently being implemented by STMA.

  2. The Protein Cost of Metabolic Fluxes: Prediction from Enzymatic Rate Laws and Cost Minimization

    Science.gov (United States)

    Noor, Elad; Flamholz, Avi; Bar-Even, Arren; Davidi, Dan; Milo, Ron; Liebermeister, Wolfram

    2016-01-01

    Bacterial growth depends crucially on metabolic fluxes, which are limited by the cell’s capacity to maintain metabolic enzymes. The necessary enzyme amount per unit flux is a major determinant of metabolic strategies both in evolution and bioengineering. It depends on enzyme parameters (such as kcat and KM constants), but also on metabolite concentrations. Moreover, similar amounts of different enzymes might incur different costs for the cell, depending on enzyme-specific properties such as protein size and half-life. Here, we developed enzyme cost minimization (ECM), a scalable method for computing enzyme amounts that support a given metabolic flux at a minimal protein cost. The complex interplay of enzyme and metabolite concentrations, e.g. through thermodynamic driving forces and enzyme saturation, would make it hard to solve this optimization problem directly. By treating enzyme cost as a function of metabolite levels, we formulated ECM as a numerically tractable, convex optimization problem. Its tiered approach allows for building models at different levels of detail, depending on the amount of available data. Validating our method with measured metabolite and protein levels in E. coli central metabolism, we found typical prediction fold errors of 4.1 and 2.6, respectively, for the two kinds of data. This result from the cost-optimized metabolic state is significantly better than randomly sampled metabolite profiles, supporting the hypothesis that enzyme cost is important for the fitness of E. coli. ECM can be used to predict enzyme levels and protein cost in natural and engineered pathways, and could be a valuable computational tool to assist metabolic engineering projects. Furthermore, it establishes a direct connection between protein cost and thermodynamics, and provides a physically plausible and computationally tractable way to include enzyme kinetics into constraint-based metabolic models, where kinetics have usually been ignored or oversimplified

  3. The Protein Cost of Metabolic Fluxes: Prediction from Enzymatic Rate Laws and Cost Minimization.

    Directory of Open Access Journals (Sweden)

    Elad Noor

    2016-11-01

    Full Text Available Bacterial growth depends crucially on metabolic fluxes, which are limited by the cell's capacity to maintain metabolic enzymes. The necessary enzyme amount per unit flux is a major determinant of metabolic strategies both in evolution and bioengineering. It depends on enzyme parameters (such as kcat and KM constants, but also on metabolite concentrations. Moreover, similar amounts of different enzymes might incur different costs for the cell, depending on enzyme-specific properties such as protein size and half-life. Here, we developed enzyme cost minimization (ECM, a scalable method for computing enzyme amounts that support a given metabolic flux at a minimal protein cost. The complex interplay of enzyme and metabolite concentrations, e.g. through thermodynamic driving forces and enzyme saturation, would make it hard to solve this optimization problem directly. By treating enzyme cost as a function of metabolite levels, we formulated ECM as a numerically tractable, convex optimization problem. Its tiered approach allows for building models at different levels of detail, depending on the amount of available data. Validating our method with measured metabolite and protein levels in E. coli central metabolism, we found typical prediction fold errors of 4.1 and 2.6, respectively, for the two kinds of data. This result from the cost-optimized metabolic state is significantly better than randomly sampled metabolite profiles, supporting the hypothesis that enzyme cost is important for the fitness of E. coli. ECM can be used to predict enzyme levels and protein cost in natural and engineered pathways, and could be a valuable computational tool to assist metabolic engineering projects. Furthermore, it establishes a direct connection between protein cost and thermodynamics, and provides a physically plausible and computationally tractable way to include enzyme kinetics into constraint-based metabolic models, where kinetics have usually been ignored or

  4. PENGARUH PROFIT MARGIN, ASSETS TURNOVER DAN LEVERAGE TERHADAP SUSTAINABLE GROWTH RATE PADA PERUSAHAAN SEKTOR JASA YANG TERDAFTAR DI BURSA EFEK INDONESIA PERIODE 2010-2012

    Directory of Open Access Journals (Sweden)

    Arim Nasim

    2015-04-01

    Full Text Available This study aims to determine the effect of Profit Margin, Assets Turnover and Leverage on Sustainable Growth Rate. The variables used are profit margin, asset turnover and leverage as independent variable and sustainable growth rate as dependent variable. This study also aims to describe the state of profit margin projected by Net Profit Margin (NPM, asset turnover proxied by Total Assets Turnover (TATO, leverage which is proxied by Debt to Equity Ratio (DER and Sustainable Growth Rate (SGR Service sector. This research was conducted on service sector companies listed in Indonesia Stock Exchange 2010-2012.Data obtained from website Bursa Efek Indonesia.Teknik data analysis used is multiple linear regression and use t-statistics to test the influence of each independent variable to variable Dependent partially.Previously done classical assumption test that includes data normality test, multicolinierity test, heteroskedastisitas test and autocorrelation test.Based on data normality test, multicolinierity test, heteroscedasticity test and autocorrelation test did not found any variables that deviate from the classical assumption.From the results of research Shows that profit margin positively affect sustainable growth rate, asset turnover have positive effect to sustainable growth rate, and leverage have positive effect to sustainable growth rate.

  5. Obstructive sleep apnea and heart rate variability in male patients with metabolic syndrome: cross-sectional study.

    Science.gov (United States)

    Véber, Orsolya; Lendvai, Zsofia; Ronai, Katalin Zsuzsanna; Dunai, Andrea; Zoller, Rezso; Lindner, Anett Virag; Turányi, Csilla Zita; Szocs, Julia Luca; Keresztes, Katalin; Tabák, Adam Gyula; Novak, Marta; Molnar, Miklos Z; Mucsi, Istvan

    2014-03-01

    Obstructive sleep apnea (OSA) is often accompanied by the metabolic syndrome. Because both conditions are associated with depressed heart rate variability (HRV) separately, our aim was to study whether co-morbid OSA is associated with more reduced HRV in male patients with the metabolic syndrome. In this cross-sectional study, 35 men (age, 57±11 years) with the metabolic syndrome (according to International Diabetes Federation criteria) were included. OSA severity was defined by the apnea-hypopnea index (AHI). HRV was assessed by 24-hr ambulatory electrocardiographic monitoring. Standard deviation of all normal-to-normal RR intervals (SDNN), the high frequency power (HFP), and the ratio of low- to high-frequency power (LF/HF) were measured. There were 14, 6, and 8 cases of severe (AHI ≥30/hr), moderate (15/hr≤AHI standardized β regression coefficient (β)=-0.362, P=0.043] and higher night/day LF/HF ratio (β=0.377, P=0.023) after controlling for age, duration of diabetes, and severity of metabolic syndrome. Co-morbid OSA is associated with decreased overall HRV, parasympathetic loss, and impaired diurnal pattern of sympathovagal balance that may further increase the cardiovascular vulnerability of male patients with the metabolic syndrome. The role of the HRV analysis in the risk assessment of these patients warrants further studies.

  6. Effects of carbohydrate quantity and glycemic index on resting metabolic rate and body composition during weight loss.

    Science.gov (United States)

    Karl, J Philip; Roberts, Susan B; Schaefer, Ernst J; Gleason, Joi A; Fuss, Paul; Rasmussen, Helen; Saltzman, Edward; Das, Sai Krupa

    2015-11-01

    To examine the effects of diets varying in carbohydrate and glycemic index (GI) on changes in body composition, resting metabolic rate (RMR), and metabolic adaptation during and after weight loss. Adults with obesity (n = 91) were randomized to one of four provided-food diets for 17 weeks. Diets differed in percentage energy from carbohydrate (55% or 70%) and GI (low or high) but were matched for protein, fiber, and energy. Body weight, body composition, RMR, and metabolic adaptation (measured RMR-predicted RMR) were measured during weight loss and subsequent weight stability. No effect of dietary carbohydrate content or GI on body weight loss or percentage of weight lost as fat mass (FM) was observed. Measured RMR was significantly lower (-226 kJ/day [95% CI: -314 to -138 kJ/day], P Metabolic adaptation did not differ by dietary carbohydrate content or GI and was not associated with weight regain 12 months later. Moderate-carbohydrate and low-GI diets did not preferentially reduce FM, preserve lean mass, or attenuate metabolic adaptation during weight loss compared to high-carbohydrate and high-GI diets. © 2015 The Obesity Society.

  7. Dissolved Organic Nitrogen Inputs from Wastewater Treatment Plant Effluents Increase Responses of Planktonic Metabolic Rates to Warming.

    Science.gov (United States)

    Vaquer-Sunyer, Raquel; Conley, Daniel J; Muthusamy, Saraladevi; Lindh, Markus V; Pinhassi, Jarone; Kritzberg, Emma S

    2015-10-06

    Increased anthropogenic pressures on coastal marine ecosystems in the last century are threatening their biodiversity and functioning. Global warming and increases in nutrient loadings are two major stressors affecting these systems. Global warming is expected to increase both atmospheric and water temperatures and increase precipitation and terrestrial runoff, further increasing organic matter and nutrient inputs to coastal areas. Dissolved organic nitrogen (DON) concentrations frequently exceed those of dissolved inorganic nitrogen in aquatic systems. Many components of the DON pool have been shown to supply nitrogen nutrition to phytoplankton and bacteria. Predictions of how global warming and eutrophication will affect metabolic rates and dissolved oxygen dynamics in the future are needed to elucidate their impacts on biodiversity and ecosystem functioning. Here, we experimentally determine the effects of simultaneous DON additions and warming on planktonic community metabolism in the Baltic Sea, the largest coastal area suffering from eutrophication-driven hypoxia. Both bacterioplankton community composition and metabolic rates changed in relation to temperature. DON additions from wastewater treatment plant effluents significantly increased the activation energies for community respiration and gross primary production. Activation energies for community respiration were higher than those for gross primary production. Results support the prediction that warming of the Baltic Sea will enhance planktonic respiration rates faster than it will for planktonic primary production. Higher increases in respiration rates than in production may lead to the depletion of the oxygen pool, further aggravating hypoxia in the Baltic Sea.

  8. Effects of dietary Gracilaria sp. and Alaria sp. supplementation on growth performance, metabolic rates and health in meagre (Argyrosomus regius) subjected to pathogen infection

    DEFF Research Database (Denmark)

    Peixoto, Maria João; Salas-Leitón, Emílio; Brito, Francisca

    2017-01-01

    . Standard and routine metabolic rates, and aerobic metabolic scope did not vary significantly among dietary treatments. Conversely, maximum metabolic rate was significantly higher in fish fed Alaria sp. diet when compared to control group. Non-infected fish had higher hematocrit levels than the infected...... enzymes activities when compared to non-infected. An interaction between infection and diet was found for glutathione peroxidase and reduced glutathione activities. The current study suggests that dietary seaweed supplementation modulates metabolic rates and biomarker responses in meagre, which may confer...

  9. Sustainable organic loading rate and energy recovery potential of mesophilic anaerobic membrane bioreactor for municipal wastewater treatment

    KAUST Repository

    Wei, Chunhai

    2014-08-01

    The overall performance of a mesophilic anaerobic membrane bioreactor (AnMBR) for synthetic municipal wastewater treatment was investigated under a range of organic loading rate (OLR). A very steady and high chemical oxygen demand (COD) removal (around 98%) was achieved over a broad range of volumetric OLR of 0.8-10gCOD/L/d. The sustainable volumetric and sludge OLR satisfying a permeate COD below 50mg/L for general reuse was 6gCOD/L/d and 0.63gCOD/gMLVSS (mixed liquor volatile suspended solids)/d, respectively. At a high sludge OLR of over 0.6gCOD/gMLVSS/d, the AnMBR achieved high methane production of over 300ml/gCOD (even approaching the theoretical value of 382ml/gCOD). A low biomass production of 0.015-0.026gMLVSS/gCOD and a sustainable flux of 6L/m2/h were observed. The integration of a heat pump and forward osmosis into the mesophilic AnMBR process would be a promising way for net energy recovery from typical municipal wastewater in a temperate area. © 2014 Elsevier Ltd.

  10. Stable Breathing in Patients With Obstructive Sleep Apnea Is Associated With Increased Effort but Not Lowered Metabolic Rate.

    Science.gov (United States)

    de Melo, Camila M; Taranto-Montemurro, Luigi; Butler, James P; White, David P; Loring, Stephen H; Azarbarzin, Ali; Marques, Melania; Berger, Philip J; Wellman, Andrew; Sands, Scott A

    2017-10-01

    In principle, if metabolic rate were to fall during sleep in a patient with obstructive sleep apnea (OSA), ventilatory requirements could be met without increased respiratory effort thereby favoring stable breathing. Indeed, most patients achieve periods of stable flow-limited breathing without respiratory events for periods during the night for reasons that are unclear. Thus, we tested the hypothesis that in patients with OSA, periods of stable breathing occur when metabolic rate (VO2) declines. Twelve OSA patients (apnea-hypopnea index >15 events/h) completed overnight polysomnography including measurements of VO2 (using ventilation and intranasal PO2) and respiratory effort (esophageal pressure). Contrary to our hypothesis, VO2 did not differ between stable and unstable breathing periods in non-REM stage 2 (208 ± 20 vs. 213 ± 18 mL/min), despite elevated respiratory effort during stable breathing (26 ± 2 versus 23 ± 2 cmH2O, p = .03). However, VO2 was lowered during deeper sleep (244 to 179 mL/min from non-REM stages 1 to 3, p = .04) in conjunction with more stable breathing. Further analysis revealed that airflow obstruction curtailed metabolism in both stable and unstable periods, since CPAP increased VO2 by 14% in both cases (p = .02, .03, respectively). Patients whose VO2 fell most during sleep avoided an increase in PCO2 and respiratory effort. OSA patients typically convert from unstable to stable breathing without lowering metabolic rate. During sleep, OSA patients labor with increased respiratory effort but fail to satisfy metabolic demand even in the absence of overt respiratory events.

  11. Hypertension prevalence and influence of basal metabolic rate on blood pressure among adult students in Bangladesh.

    Science.gov (United States)

    Ali, Nurshad; Mahmood, Shakil; Manirujjaman, M; Perveen, Rasheda; Al Nahid, Abdullah; Ahmed, Shamim; Khanum, Farida Adib; Rahman, Mustafizur

    2017-07-25

    Hypertension is a global health issue and is currently increasing at rapid pace in South Asian countries including Bangladesh. Although, some studies on hypertension have been conducted in Bangladesh, there is a lack of scientific evidence in the adult student population that was missing from the previous and recent national cross-sectional studies. Moreover, the specific risk factors of hypertension in the Bangladeshi adults still need to be investigated. This study was conducted to estimate hypertension prevalence among adult students in Bangladesh and to test the hypothesis of Luke et al. (Hypertension 43:555-560, 2004) that basal metabolic rate (BMR) and blood pressure are positively associated independent of body size. The data was collected on 184 adult university students (118 female and 66 male) in Dhaka, Bangladesh. Anthropometric, BMR details and an average of at least two blood pressure measurements were obtained. Hypertension was defined by a systolic blood pressure (SBP) ≥ 140 mmHg and/or, diastolic blood pressure (DBP) ≥ 90 mmHg. Overall, 6.5% of participants had hypertension with significantly (p < 0.001) higher prevalence in male (12.1%) than in the female (3.4%) students. Age and BMI showed positive and significant correlation with hypertension among the students. When adjusted for body mass index (BMI), as well as other potentially confounding variables such as age, sex, smoking status and degree of urbanization, BMR was positively correlated with SBP and DBP (p < 0.001). Thus, higher BMR is associated with SBP and DBP; this is opposite the well documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMR might be an important predictor that can explain relatively high blood pressure and hypertension in humans. This study reports the prevalence and associated risk factors of hypertension in the Bangladeshi adult students. The

  12. Hypertension prevalence and influence of basal metabolic rate on blood pressure among adult students in Bangladesh

    Directory of Open Access Journals (Sweden)

    Nurshad Ali

    2017-07-01

    Full Text Available Abstract Background Hypertension is a global health issue and is currently increasing at rapid pace in South Asian countries including Bangladesh. Although, some studies on hypertension have been conducted in Bangladesh, there is a lack of scientific evidence in the adult student population that was missing from the previous and recent national cross-sectional studies. Moreover, the specific risk factors of hypertension in the Bangladeshi adults still need to be investigated. This study was conducted to estimate hypertension prevalence among adult students in Bangladesh and to test the hypothesis of Luke et al. (Hypertension 43:555–560, 2004 that basal metabolic rate (BMR and blood pressure are positively associated independent of body size. Method The data was collected on 184 adult university students (118 female and 66 male in Dhaka, Bangladesh. Anthropometric, BMR details and an average of at least two blood pressure measurements were obtained. Hypertension was defined by a systolic blood pressure (SBP ≥ 140 mmHg and/or, diastolic blood pressure (DBP ≥ 90 mmHg. Results Overall, 6.5% of participants had hypertension with significantly (p < 0.001 higher prevalence in male (12.1% than in the female (3.4% students. Age and BMI showed positive and significant correlation with hypertension among the students. When adjusted for body mass index (BMI, as well as other potentially confounding variables such as age, sex, smoking status and degree of urbanization, BMR was positively correlated with SBP and DBP (p < 0.001. Thus, higher BMR is associated with SBP and DBP; this is opposite the well documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMR might be an important predictor that can explain relatively high blood pressure and hypertension in humans. Conclusion This study reports the prevalence and associated risk factors

  13. Metabolic and protein interaction sub-networks controlling the proliferation rate of cancer cells and their impact on patient survival.

    Science.gov (United States)

    Feizi, Amir; Bordel, Sergio

    2013-10-24

    Cancer cells can have a broad scope of proliferation rates. Here we aim to identify the molecular mechanisms that allow some cancer cell lines to grow up to 4 times faster than other cell lines. The correlation of gene expression profiles with the growth rate in 60 different cell lines has been analyzed using several genome-scale biological networks and new algorithms. New possible regulatory feedback loops have been suggested and the known roles of several cell cycle related transcription factors have been confirmed. Over 100 growth-correlated metabolic sub-networks have been identified, suggesting a key role of simultaneous lipid synthesis and degradation in the energy supply of the cancer cells growth. Many metabolic sub-networks involved in cell line proliferation appeared also to correlate negatively with the survival expectancy of colon cancer patients.

  14. Non-invasive Estimation of Metabolic Uptake Rate of Glucose using F18-FDG PET and Linear Transformation of Outputs

    DEFF Research Database (Denmark)

    Christensen, Anders Nymark; Reichkendler, M.; Auerback, P.

    different standard deviations with the best method-Parker and Feng- at 0.0030 i. e. around 10 %. Conclusion: Based on this study, we can estimate the metabolic uptake rate of glucose with good accuracy and precision in similar future studies without blood sampling. Given the high variance of the femoral......For quantitative analysis and kinetic modeling of dynamic PET-data an input function is needed. Normally this is obtained by arterial blood sampling, potentially an unpleasant experience for the patient and laborious for the staff. Aim: To validate methods for determination of the metabolic uptake...... rate (Km) of glucose from dynamic FDG-PET scans using Image Derived Input Functions (IDIF) without blood sampling. Method: We performed 24 dynamic FDG-PET scans of the thigh of 14 healthy young male volunteers during a hyperinsulinemic isoglycemic clamp. Ten of the subjects were scanned twice 11 weeks...

  15. Essential fatty acids influence metabolic rate and tolerance of hypoxia in Dover sole ( Solea solea ) larvae and juveniles

    DEFF Research Database (Denmark)

    McKenzie, David; Lund, Ivar; Pedersen, Per Bovbjerg

    2008-01-01

    Dover sole (Solea solea, Linneaus 1758) were raised from first feeding on brine shrimp (Artemia sp.) with different contents and compositions of the essential fatty acids (EFA) arachidonic acid (ARA, 20:4n - 6); eicosapentaenoic acid (EPA, 20:5n - 3), and docosahexaenoic acid (DHA, 22:6n - 3......), and their metabolic rate and tolerance to hypoxia measured prior to and following metamorphosis and settlement. Four dietary Artemia preparations were compared: (1) un-enriched; (2) enriched with a commercial EFA mixture (Easy DHA SELCO Emulsion); (3) enriched with a marine fish oil combination (VEVODAR and Incromega...... DHA) to provide a high ratio of ARA to DHA, and (4) enriched with these fish oils to provide a low ratio of ARA to DHA. Sole fed un-enriched Artemia were significantly less tolerant to hypoxia than the other dietary groups. Larvae from this group had significantly higher routine metabolic rate (RMR...

  16. A Hyporheic Mesocosm Experiment: Influence of Quantity and Quality of stream-source DOC on Rates of Hyporheic Metabolism

    Science.gov (United States)

    Serchan, S. P.; Wondzell, S. M.; Haggerty, R.; Pennington, R.; Feris, K. P.; Sanfilippo, A. R.; Reeder, W. J.; Tonina, D.

    2016-12-01

    Hyporheic zone biogeochemical processes can influence stream water chemistry. Some estimates show that 50-90% stream water CO2 is produced in the hyporheic zone through heterotrophic metabolism of organic matter, usually supplied from the stream as dissolved organic carbon (DOC). Preliminary results from our well network at the HJ Andrews WS1, indicate that dissolved inorganic carbon (DIC) is 1.5-2 times higher in the hyporheic zone than in stream water. Conversely, DOC (mg/L) is 1.5 times higher in stream water than in the hyporheic zone throughout the year. Overall, the hyporheic zone appears to be a net source of DIC. However, the increase in DIC along hyporheic flow paths is approximately 10-times greater than the loss of DOC, suggesting that metabolism of buried particulate organic carbon (POC) is a major source of organic carbon for microbial metabolism. However, we cannot completely rule out alternative sources of DIC, especially those originating in the overlying riparian soil, because hyporheic processes are difficult to isolate in well networks. To study hyporheic zone biogeochemical processes, particularly the transformation of organic carbon to inorganic carbon species, we designed and built six replicate 2-m long hyporheic mesocosms in which we are conducting DOC amendment experiments. We examine the role of DOC quality and quantity on hyporheic respiration by injecting labile (acetate) and refractory (fulvic acid) organic carbon and comparing rates of O2 consumption, DOC loss, and DIC gains against a control. We expect that stream source DOC is limiting in this small headwater stream, forcing hyporheic metabolism to rely on buried POC. However, the long burial time of POC suggests it is likely of low quality so that supplying labile DOC in stream water should shift hyporheic metabolism away from POC rather than increase the overall rate of metabolism. Future experiments will examine natural sources of DOC (stream periphyton, leaf, and soil humic

  17. Screening for Mental Health Problems: Addressing the Base Rate Fallacy for a Sustainable Screening Program in Integrated Primary Care.

    Science.gov (United States)

    Lavigne, John V; Feldman, Marissa; Meyers, Kathryn Mendelsohn

    2016-11-01

    The Affordable Care Act has stimulated interest in screening for psychological problems in primary care. Given the scale with which screening might occur, the implications of a problem known as the base rate fallacy need to be considered. The concepts of sensitivity and specificity, positive and negative predictive value, and the base rate fallacy are discussed. The possibility that a screening program may not improve upon random selection is reviewed, as is the possibility that sequential screening might be useful. Developing effective screening programs for pediatric mental health problems is highly desirable, and properly addressing the high rate of false positives may improve the likelihood that such programs can be sustained. Consideration needs to be given to the use of sequential screening, which has both advantages and disadvantages, depending upon the type of problem to be screened for and the availability of resources for follow-up evaluations. © The Author 2016. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. INFLUENCE OF TRIMETAZIDINE METABOLIC THERAPY ON CONNECTIVE TISSUE METABOLISM IN EXPERIMENTAL DIFFUSE ISCHEMIC NECROTIC CARDIOSCLEROSIS IN RATS WITH DIFFERENT RATES OF HYPOXIA RESISTANCE

    Directory of Open Access Journals (Sweden)

    H. S. Saturska

    2016-05-01

    Full Text Available Background. The change in metabolism of the connective tissue elements of heart is the central chain in pathogenesis of diffuse ischemic necrotic cardiosclerosis (DINC, which occurs after repeated epinephrine injury of myocardial tissues. Objective. This study proves that trimetazidine (TM metabolic therapy has a protective effect on the development of DINC in rats with different rates of hypoxia resistance. Methods. Male white rats were divided into three groups due to the different rates of hypoxia resistance by means of the method of hypobaric hypoxia: rats with low, middle and high rates of hypoxia resistance. Each group was divided into equal subgroups: a control group, a DINC group (injections of epinephrine hydrotartrate (0,5 mg/kg of body weight and calcium gluconate (5 mg/kg of body weight two times, a control group administrated with trimetazidine dihydrochloride (10 mg/kg of body weight, a DINC group treated with TM every day (10 mg/kg of body weight for all period of observation. Concentration of protein-bound oxyproline in blood serum was evaluated on the 7th, 14th and 30th days after the pathology simulation. Histological examination of Masson trichrome staining of myocardium was performed on the 30th days after the pathology simulation. Results. DINC increased the concentration of protein-bound oxyproline in blood serum on the 7th, 14th and 30th days after the pathology simulation, and followed by metabolic imbalances in diffuse connective tissue elements, which are rich in collagens. DINC+TM increased the concentration of protein-bound oxyproline in blood serum less intensively. Conclusions. The intensity of metabolic imbalances in diffuse connective tissue elements is the highest in the low resistant animals to hypoxia. Those results are confirmed by histological examination of the myocardium of rats with different resistance to hypoxia. Fibrotic regions in myocardium are rich in collagens. It has been revealed that the most

  19. A comparative analysis of metabolic rate in six Scarabaeus species (Coleoptera: Scarabaeidae) from southern Africa: further caveats when inferring adaptation.

    Science.gov (United States)

    Davis, A L.V.; Chown, S L.; McGeoch, M A.; Scholtz, C H.

    2000-04-01

    Alterations in VO(2) or VCO(2) are amongst the more polemical physiological adaptations ascribed to insects. Generally, metabolic rate is thought to be lowered in response to arid conditions, and elevated in species from cold environments compared to their more temperate relatives. However, most studies have rarely addressed the influence of both environmental factors in unison. To this end, standard metabolic rate and its temperature dependence were measured (at 4 degrees C intervals from 16 to 32 degrees C) in six Scarabaeus dung beetle species (three flightless, three volant) from a variety of habitats (warm, arid to cool, mesic) in southern Africa using flow-through respirometry. Mass specific VCO(2) varied from 0.0158 ml g(-1) h(-1) at 16 degrees C to 0.1839 ml g (-1) h(-1) at 32 degrees C. The slopes of the rate temperature curves were similar for all species (Q(10)s of 2.14-2.84), although the intercepts differed significantly in the direction (warm arid to cool mesic): S. gariepinusgalenusmetabolic rate modulation, and especially metabolic cold adaptation, in insects must take both temperature and water availability into account.

  20. Organ-specific rates of cellular respiration in developing sunflower seedlings and their bearing on metabolic scaling theory.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2012-10-01

    Fifty years ago Max Kleiber described what has become known as the "mouse-to-elephant" curve, i.e., a log-log plot of basal metabolic rate versus body mass. From these data, "Kleiber's 3/4 law" was deduced, which states that metabolic activity scales as the three fourths-power of body mass. However, for reasons unknown so far, no such "universal scaling law" has been discovered for land plants (embryophytes). Here, we report that the metabolic rates of four different organs (cotyledons, cotyledonary hook, hypocotyl, and roots) of developing sunflower (Helianthus annuus L.) seedlings grown in darkness (skotomorphogenesis) and in white light (photomorphogenesis) differ by a factor of 2 to 5 and are largely independent of light treatment. The organ-specific respiration rate (oxygen uptake per minute per gram of fresh mass) of the apical hook, which is composed of cells with densely packaged cytoplasm, is much higher than that of the hypocotyl, an organ that contains vacuolated cells. Data for cell length, cell density, and DNA content reveal that (1) hook opening in white light is caused by a stimulation of cell elongation on the inside of the curved organ, (2) respiration, cell density and DNA content are much higher in the hook than in the stem, and (3) organ-specific respiration rates and the DNA contents of tissues are statistically correlated. We conclude that, due to the heterogeneity of the plant body caused by the vacuolization of the cells, Kleiber's law, which was deduced using mammals as a model system, cannot be applied to embryophytes. In plants, this rule may reflect scaling phenomena at the level of the metabolically active protoplasmic contents of the cells.

  1. Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage.

    Science.gov (United States)

    Benson, Roger B J; Campione, Nicolás E; Carrano, Matthew T; Mannion, Philip D; Sullivan, Corwin; Upchurch, Paul; Evans, David C

    2014-05-01

    Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of

  2. Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage.

    Directory of Open Access Journals (Sweden)

    Roger B J Benson

    2014-05-01

    Full Text Available Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large

  3. Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage

    Science.gov (United States)

    Benson, Roger B. J.; Campione, Nicolás E.; Carrano, Matthew T.; Mannion, Philip D.; Sullivan, Corwin; Upchurch, Paul; Evans, David C.

    2014-01-01

    Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614–622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation

  4. Impact of growth mode, phase, and rate on the metabolic state of the extremely thermophilic archaeon Pyrococcus furiosus.

    Science.gov (United States)

    Khatibi, Piyum A; Chou, Chung-Jung; Loder, Andrew J; Zurawski, Jeffrey V; Adams, Michael W W; Kelly, Robert M

    2017-12-01

    The archaeon Pyrococcus furiosus is emerging as a metabolic engineering platform for production of fuels and chemicals, such that more must be known about this organism's characteristics in bioprocessing contexts. Its ability to grow at temperatures from 70 to greater than 100°C and thereby avoid contamination, offers the opportunity for long duration, continuous bioprocesses as an alternative to batch systems. Toward that end, we analyzed the transcriptome of P. furiosus to reveal its metabolic state during different growth modes that are relevant to bioprocessing. As cells progressed from exponential to stationary phase in batch cultures, genes involved in biosynthetic pathways important to replacing diminishing supplies of key nutrients and genes responsible for the onset of stress responses were up-regulated. In contrast, during continuous culture, the progression to higher dilution rates down-regulated many biosynthetic processes as nutrient supplies were increased. Most interesting was the contrast between batch exponential phase and continuous culture at comparable growth rates (∼0.4 hr-1 ), where over 200 genes were differentially transcribed, indicating among other things, N-limitation in the chemostat and the onset of oxidative stress. The results here suggest that cellular processes involved in carbon and electron flux in P. furiosus were significantly impacted by growth mode, phase and rate, factors that need to be taken into account when developing successful metabolic engineering strategies. © 2017 Wiley Periodicals, Inc.

  5. Intracerebroventricular injection of murine leptin enhances the postprandial metabolic rate in the rat

    NARCIS (Netherlands)

    Ruffin, MP; Nicolaidis, S

    2000-01-01

    Energy balance is achieved by means of a concomitant control of both food intake and energy expenditure. Leptin, synthesized in the adipose tissue, acts on brain structures and lowers body weight by inhibiting food intake and in parallel by enhancing energy expenditure i.e. metabolism or one of its

  6. Post-natal exposure to corticosterone affects standard metabolic rate in the zebra finch (Taeniopygia guttata)

    NARCIS (Netherlands)

    Spencer, K. A.; Verhulst, S.

    2008-01-01

    Post-natal stress has been shown to have important short and long term effects on many adult traits in birds. During stress, metabolic alterations often result in the mobilization of energy away from energy-sensitive functions such as growth, which could have significant implications for developing

  7. Respirometry increases cortisol levels in rainbow trout Oncorhynchus mykiss: implications for measurements of metabolic rate

    DEFF Research Database (Denmark)

    Murray, L.; Rennie, M. D.; Svendsen, Jon Christian

    2017-01-01

    This study aimed to assess the extent to which chasing, handling and confining Oncorhynchus mykiss to a small respirometer chamber during respirometric experiments is stressful and affects metabolic measurements. The study observed increased cortisol levels in animals tested using a chase protocol...

  8. Costly neighbours: Heterospecific competitive interactions increase metabolic rates in dominant species

    Czech Academy of Sciences Publication Activity Database

    Janča, M.; Gvoždík, Lumír

    2017-01-01

    Roč. 7, č. 5177 (2017), č. článku 5177. ISSN 2045-2322 R&D Projects: GA ČR(CZ) GA15-07140S Institutional support: RVO:68081766 Keywords : interference competition * intraspecific variation * terrestrial salamander * energy metabolism * natural selection * newts Subject RIV: EG - Zoology Impact factor: 4.259, year: 2016

  9. Effects of temperature and salinity on metabolic rate of the Asiatic clam Corbicula fluminea (Müller, 1774).

    Science.gov (United States)

    Xiao, Bai-Cai; Li, Er-Chao; Du, Zhen-Yu; Jiang, Run-Lan; Chen, Li-Qiao; Yu, Na

    2014-01-01

    The effects of temperature and salinity on the metabolism of the Asiatic clam Corbicula fluminea (mollusca, Lamellibranchia) were studied experimentally. Firstly, three indexes of basal metabolism (oxygen consumption rate, OCR; ammonia excretion rate, AER; and CO2 emission rate, CER), patterns of diurnal rhythm and O: N ratios were measured for three size ranges (large: h = 25.54 ± 1.96 mm, medium: h = 22.07 ± 1.33 mm and small: h = 17.70 ± 1.43 mm) at two salinities (0.3‰ and 1.8‰). The results showed that: (1) three indexes decreased with increasing body size. (2) no significant difference was found between two salinities for the O: N ratios of the small and large size, but a significant difference was found for the medium-sized one; (3) however, there were similar and distinct diurnal rhythms of metabolic rate at two salinities over a 24 hour period in three size C. fluminea. N ratios and Q10 (temperature coefficient) of small-sized C. fluminea were measured across five water temperatures (4, 11, 18, 25 and 32°C) and two salinities (0.3‰ and 1.8‰) in the following experiments. Our results of the small C. fluminea were as follows: there was no significant difference in the O: N ratios among the five temperatures and two salinity treatments; and no significant difference of three indexes between both salinity levels were observed at same temperature controlled; and three indexes increased significantly with increasing temperature from 4°C to 25°C, while no significant difference was observed in the 25-32°C range; and the highest Q10 coefficients (Q10 = 1.825 at salinity of 0.3‰ and Q10 = 1.683 at salinity of 1.8‰) were observed at the 18-25°C temperature increase, and the low values were found in the 4-11°C, 11-18°C and 25-32°C interval. It indicates that there is not a synergetic effect of our temperature and salinity on the metabolic rate of small C. fluminea, and a temperature of 18-25°C may represent an optimum adequate metabolic

  10. Role of metabolic rate and DNA-repair in Drosophila aging Implications for the mitochondrial mutation theory of aging

    Science.gov (United States)

    Miquel, J.; Binnard, R.; Fleming, J. E.

    1983-01-01

    The notion that injury to mitochondrial DNA is a cause of intrinsic aging was tested by correlating the different respiration rates of several wild strains of Drosophila melanogaster with the life-spans. Respiration rate and aging in a mutant of D. melanogaster deficient in postreplication repair were also investigated. In agreement with the rate of living theory, there was an inverse relation between oxygen consumption and median life-span in flies having normal DNA repair. The mutant showed an abnormally low life-span as compared to the controls and also exhibited significant deficiency in mating fitness and a depressed metabolic rate. Therefore, the short life-span of the mutant may be due to the congenital condition rather than to accelerated aging.

  11. Respirometry increases cortisol levels in rainbow trout Oncorhynchus mykiss: implications for measurements of metabolic rate.

    Science.gov (United States)

    Murray, L; Rennie, M D; Svendsen, J C; Enders, E C

    2017-05-01

    This study aimed to assess the extent to which chasing, handling and confining Oncorhynchus mykiss to a small respirometer chamber during respirometric experiments is stressful and affects metabolic measurements. The study observed increased cortisol levels in animals tested using a chase protocol and subsequent intermittent-flow respirometry, suggesting that this procedural treatment may stress animals. © 2017 The Fisheries Society of the British Isles.

  12. The Effect of Saquinavir on the Rate of Metabolism of Midazolam

    Science.gov (United States)

    1999-10-01

    margin of safety of a therapy ( Katzung , 1997). V max The maximal velocity of the biotransformation of a specific drug ( Katzung , 1997). Volume of...Distribution (Vd) The amount of drug present in the body in relation to the concentration of the drug in the plasma expressed in liters ( Katzung , 1997...Charlhant, D., Dreano, Y., Picart, D., Lohezic, F. & Riche, C. (1998). Drug Metabolism and Disposition, 26, 257-260. Katzung , B. (Ed.). (1998). Basic

  13. Effect of resistance training on resting metabolic rate and its estimation by a dual-energy X-ray absorptiometry metabolic map.

    Science.gov (United States)

    Aristizabal, J C; Freidenreich, D J; Volk, B M; Kupchak, B R; Saenz, C; Maresh, C M; Kraemer, W J; Volek, J S

    2015-07-01

    Fat-free mass (FFM) is the major predictor of resting metabolic rate (RMR). As protein supplementation during resistance training may augment gains in FFM, we investigated the effects of resistance training combined with protein supplementation on RMR and whether RMR responses could be estimated by a dual-energy X-ray absorptiometry (DXA) metabolic map. Healthy adults completed a whole-body periodized resistance training program consisting of 96 workouts (~9 months). Participants were randomly assigned to supplement with whey protein (whey; n=18), soy protein (soy; n=21) or carbohydrate (carb; n=22). RMR was measured using indirect calorimetry (RMR(IC)) and estimated by DXA metabolic mapping (RMR(MM)) pretraining and posttraining. RMR(IC) increased from pretraining to posttraining in the whole cohort (1653±302 to 1726±291 kcal/day, P=0.001) without differences between the groups. Delta RMR(IC) and RMR(MM) (73±158 vs 52±41 kcal/day were not significantly different by t-test (P=0.303), although they were not significantly correlated (r=0.081; P=0.535). Stepwise regression identified 43% of the shared variance in delta RMR(IC) using total serum thyroxine, RMR(IC) and FFM at baseline (P=0.009). These results indicate that 9 months of resistance training significantly increased RMR ~5% on average, but there was wide variability between individuals, which can be partially accounted for by changes in FFM and thyroid hormones.

  14. Field metabolic rate and PCB adipose tissue deposition efficiency in East Greenland polar bears derived from contaminant monitoring data.

    Science.gov (United States)

    Pavlova, Viola; Nabe-Nielsen, Jacob; Dietz, Rune; Svenning, Jens-Christian; Vorkamp, Katrin; Rigét, Frank Farsø; Sonne, Christian; Letcher, Robert J; Grimm, Volker

    2014-01-01

    Climate change will increasingly affect the natural habitat and diet of polar bears (Ursus maritimus). Understanding the energetic needs of polar bears is therefore important. We developed a theoretical method for estimating polar bear food consumption based on using the highly recalcitrant polychlorinated biphenyl (PCB) congener, 2,2',4,4',55-hexaCB (CB153) in bear adipose tissue as an indicator of food intake. By comparing the CB153 tissue concentrations in wild polar bears with estimates from a purposely designed individual-based model, we identified the possible combinations of field metabolic rates (FMR) and CB153 deposition efficiencies in East Greenland polar bears. Our simulations indicate that if 30% of the CB153 consumed by polar bear individuals were deposited into their adipose tissue, the corresponding FMR would be only two times the basal metabolic rate. In contrast, if the modelled CB153 deposition efficiency were 10%, adult polar bears would require six times more energy than that needed to cover basal metabolism. This is considerably higher than what has been assumed for polar bears in previous studies though it is similar to FMRs found in other marine mammals. An implication of this result is that even relatively small reductions in future feeding opportunities could impact the survival of East Greenland polar bears.

  15. Field metabolic rate and PCB adipose tissue deposition efficiency in East Greenland polar bears derived from contaminant monitoring data.

    Directory of Open Access Journals (Sweden)

    Viola Pavlova

    Full Text Available Climate change will increasingly affect the natural habitat and diet of polar bears (Ursus maritimus. Understanding the energetic needs of polar bears is therefore important. We developed a theoretical method for estimating polar bear food consumption based on using the highly recalcitrant polychlorinated biphenyl (PCB congener, 2,2',4,4',55-hexaCB (CB153 in bear adipose tissue as an indicator of food intake. By comparing the CB153 tissue concentrations in wild polar bears with estimates from a purposely designed individual-based model, we identified the possible combinations of field metabolic rates (FMR and CB153 deposition efficiencies in East Greenland polar bears. Our simulations indicate that if 30% of the CB153 consumed by polar bear individuals were deposited into their adipose tissue, the corresponding FMR would be only two times the basal metabolic rate. In contrast, if the modelled CB153 deposition efficiency were 10%, adult polar bears would require six times more energy than that needed to cover basal metabolism. This is considerably higher than what has been assumed for polar bears in previous studies though it is similar to FMRs found in other marine mammals. An implication of this result is that even relatively small reductions in future feeding opportunities could impact the survival of East Greenland polar bears.

  16. The Circadian Clock Components CRY1 and CRY2 Are Necessary to Sustain Sex Dimorphism in Mouse Liver Metabolism*

    Science.gov (United States)

    Bur, Isabelle M.; Cohen-Solal, Anne M.; Carmignac, Danielle; Abecassis, Pierre-Yves; Chauvet, Norbert; Martin, Agnès O.; van der Horst, Gijsbertus T. J.; Robinson, Iain C. A. F.; Maurel, Patrick; Mollard, Patrice; Bonnefont, Xavier

    2009-01-01

    In mammals, males and females exhibit anatomical, hormonal, and metabolic differences. A major example of such sex dimorphism in mouse involves hepatic drug metabolism, which is also a noticeable target of circadian timekeeping. However, whether the circadian clock itself contributes to sex-biased metabolism has remained unknown, although several daily output parameters differ between sexes in a number of species, including humans. Here we show that dimorphic liver metabolism is altered when the circadian regulators Cryptochromes, Cry1 and Cry2, are inactivated. Indeed, double mutant Cry1–/– Cry2–/– male mice that lack a functional circadian clock express a number of sex-specific liver products, including several cytochrome P450 enzymes, at levels close to those measured in females. In addition, body growth of Cry-deficient mice is impaired, also in a sex-biased manner, and this phenotype goes along with an altered pattern of circulating growth hormone (GH) in mutant males, specifically. It is noteworthy that hormonal injections able to mimic male GH pulses reversed the feminized gene expression profile in the liver of Cry1–/– Cry2–/– males. Altogether, our observations suggest that the 24-h clock paces the dimorphic ultradian pulsatility of GH that is responsible for sex-dependent liver activity. We thus conclude that circadian timing, sex dimorphism, and liver metabolism are finely interconnected. PMID:19211562

  17. Growth hormone transgenic tilapia (Oreochromis sp.) compensate for increased metabolic rate to preserve exercise performance and hypoxia tolerance

    DEFF Research Database (Denmark)

    McKenzie, D.J.; Martínez, R.; Morales, A.

    2001-01-01

    was linked to elevated rates of maintenance metabolism in transgenics, and if this, in turn, influenced their scope to increase O2 uptake and perform exercise or their ability to maintain O2 uptake during progressive hypoxia. Individual transgenics or wild-types, of similar mass and length (60.0 ± 10 g...... reductions in water O2 partial pressures (PO2) from 18.4 down to 1.3 kPa), and O2 uptake measured at each PO2. Despite higher routine rates of O2 uptake in transgenics, the critical PO2 at which O2 uptake fell below the normoxic rate was similar in transgenics and wild-types (2.75 ± 0.30 vs. 4.16 ± 1.53 k......Pa, respectively). The results indicate that stimulation of growth consequent to ectopic expression of growth hormone in transgenic tilapia (Martinez et al. 1999) is linked to increased rates of maintenance metabolism. The swimming and hypoxia experiments indicate, however, that the transgenics were able...

  18. Peripheral reduction of FGFR4 with antisense oligonucleotides increases metabolic rate and lowers adiposity in diet-induced obese mice.

    Directory of Open Access Journals (Sweden)

    Xing Xian Yu

    Full Text Available Obesity is a primary risk factor for multiple metabolic disorders. Many drugs for the treatment of obesity, which mainly act through CNS as appetite suppressants, have failed during development or been removed from the market due to unacceptable adverse effects. Thus, there are very few efficacious drugs available and remains a great unmet medical need for anti-obesity drugs that increase energy expenditure by acting on peripheral tissues without severe side effects. Here, we report a novel approach involving antisense inhibition of fibroblast growth factor receptor 4 (FGFR4 in peripheral tissues. Treatment of diet-induce obese (DIO mice with FGFR4 antisense oligonucleotides (ASO specifically reduced liver FGFR4 expression that not only resulted in decrease in body weight (BW and adiposity in free-feeding conditions, but also lowered BW and adiposity under caloric restriction. In addition, combination treatment with FGFR4 ASO and rimonabant showed additive reduction in BW and adiposity. FGFR4 ASO treatment increased basal metabolic rate during free-feeding conditions and, more importantly, prevented adaptive decreases of metabolic rate induced by caloric restriction. The treatment increased fatty acid oxidation while decreased lipogenesis in both liver and fat. Mechanistic studies indicated that anti-obesity effect of FGFR4 ASO was mediated at least in part through an induction of plasma FGF15 level resulted from reduction of hepatic FGFR4 expression. The anti-obesity effect was accompanied by improvement in plasma glycemia, whole body insulin sensitivity, plasma lipid levels and liver steatosis. Therefore, FGFR4 could be a potential novel target and antisense reduction of hepatic FGFR4 expression could be an efficacious therapy as an adjunct to diet restriction or to an appetite suppressant for the treatment of obesity and related metabolic disorders.

  19. Heat dissipation does not suppress an immune response in laboratory mice divergently selected for basal metabolic rate (BMR).

    Science.gov (United States)

    Książek, Aneta; Konarzewski, Marek

    2016-05-15

    The capacity for heat dissipation is considered to be one of the most important constraints on rates of energy expenditure in mammals. To date, the significance of this constraint has been tested exclusively under peak metabolic demands, such as during lactation. Here, we used a different set of metabolic stressors, which do not induce maximum energy expenditures and yet are likely to expose the potential constraining effect of heat dissipation. We compared the physiological responses of mice divergently selected for high (H-BMR) and low basal metabolic rate (L-BMR) to simultaneous exposure to the keyhole limpet haemocyanin (KLH) antigen and high ambient temperature (Ta). At 34°C (and at 23°C, used as a control), KLH challenge resulted in a transient increase in core body temperature (Tb) in mice of both line types (by approximately 0.4°C). Warm exposure did not produce line-type-dependent differences in Tb (which was consistently higher by ca. 0.6°C in H-BMR mice across both Ta values), nor did it result in the suppression of antibody synthesis. These findings were also supported by the lack of between-line-type differences in the mass of the thymus, spleen or lymph nodes. Warm exposure induced the downsizing of heat-generating internal organs (small intestine, liver and kidneys) and an increase in intrascapular brown adipose tissue mass. However, these changes were similar in scope in both line types. Mounting a humoral immune response in selected mice was therefore not affected by ambient temperature. Thus, a combined metabolic challenge of high Ta and an immune response did not appreciably compromise the capacity to dissipate heat, even in the H-BMR mice. © 2016. Published by The Company of Biologists Ltd.

  20. Sustainable urban metabolism as a link between bio-physical sciences and urban planning: The BRIDGE project

    NARCIS (Netherlands)

    Chrysoulakis, N.; Lopes, M.; San José, R.; Grimmond, C.S.B.; Jones, M.B.; Magliulo, V.; Klostermann, J.E.M.; Synnefa, A.; Mitraka, Z.; Castro, E.; González, A.; Vogt, R.; Vesala, T.; Spano, D.; Pigeon, G.; Freer-Smith, P.; Staszewski, T.; Hodges, N.; Mills, G.; Cartalis, C.

    2013-01-01

    Urban metabolism considers a city as a system with flows of energy and material between it and the environment. Recent advances in bio-physical sciences provide methods and models to estimate local scale energy, water, carbon and pollutant fluxes. However, good communication is required to provide

  1. Anesthetic Management of a Patient with Sustained Severe Metabolic Alkalosis and Electrolyte Abnormalities Caused by Ingestion of Baking Soda

    Directory of Open Access Journals (Sweden)

    Jose Soliz

    2014-01-01

    Full Text Available The use of alternative medicine is prevalent worldwide. However, its effect on intraoperative anesthetic care is underreported. We report the anesthetic management of a patient who underwent an extensive head and neck cancer surgery and presented with a severe intraoperative metabolic alkalosis from the long term ingestion of baking soda and other herbal remedies.

  2. Anesthetic management of a patient with sustained severe metabolic alkalosis and electrolyte abnormalities caused by ingestion of baking soda.

    Science.gov (United States)

    Soliz, Jose; Lim, Jeffrey; Zheng, Gang

    2014-01-01

    The use of alternative medicine is prevalent worldwide. However, its effect on intraoperative anesthetic care is underreported. We report the anesthetic management of a patient who underwent an extensive head and neck cancer surgery and presented with a severe intraoperative metabolic alkalosis from the long term ingestion of baking soda and other herbal remedies.

  3. Understanding water deficit stress-induced changes in the basic metabolism of higher plants - biotechnologically and sustainably improving agriculture and the ecoenvironment in arid regions of the globe.

    Science.gov (United States)

    Shao, Hong-Bo; Chu, Li-Ye; Jaleel, C Abdul; Manivannan, P; Panneerselvam, R; Shao, Ming-An

    2009-01-01

    Water is vital for plant growth, development and productivity. Permanent or temporary water deficit stress limits the growth and distribution of natural and artificial vegetation and the performance of cultivated plants (crops) more than any other environmental factor. Productive and sustainable agriculture necessitates growing plants (crops) in arid and semiarid regions with less input of precious resources such as fresh water. For a better understanding and rapid improvement of soil-water stress tolerance in these regions, especially in the water-wind eroded crossing region, it is very important to link physiological and biochemical studies to molecular work in genetically tractable model plants and important native plants, and further extending them to practical ecological restoration and efficient crop production. Although basic studies and practices aimed at improving soil water stress resistance and plant water use efficiency have been carried out for many years, the mechanisms involved at different scales are still not clear. Further understanding and manipulating soil-plant water relationships and soil-water stress tolerance at the scales of ecology, physiology and molecular biology can significantly improve plant productivity and environmental quality. Currently, post-genomics and metabolomics are very important in exploring anti-drought gene resources in various life forms, but modern agriculturally sustainable development must be combined with plant physiological measures in the field, on the basis of which post-genomics and metabolomics have further practical prospects. In this review, we discuss physiological and molecular insights and effects in basic plant metabolism, drought tolerance strategies under drought conditions in higher plants for sustainable agriculture and ecoenvironments in arid and semiarid areas of the world. We conclude that biological measures are the bases for the solutions to the issues relating to the different types of

  4. Is mass-based metabolism rate proportional to surface area in plant leaves? A data re-analysis.

    Science.gov (United States)

    Jin, Dongmei; Dai, Yiqiang; Sun, Li; Sun, Shucun

    2008-06-01

    We re-analyzed two large published databases on leaf traits of plant species from seven different biomes, and determined the scaling relationship between leaf metabolism rate (mass-based photosynthesis capacity, A(mass), and mass-based dark respiration, Rd(mass)) and specific leaf area (SLA) across biomes, using a standardized major axis (SMA) method. Overall pooled data produced a scaling exponent of 1.33 for the relationship between A(mass) and SLA, significantly larger than 1.0; and 1.04 between Rd(mass) and SLA. The scaling exponent of the relationship between A(mass) and SLA ranged between 1.23 (in tropical forest) and 1.66 (in alpine biome), and it was significantly larger in alpine (1.66) and grass/meadow (1.52) biomes than in tropical forest (1.23) and wetland (1.27). The exponent of the relationship between Rd(mass) and SLA, however, was much smaller in wetland (1.05) than in temperate forest (1.29) and tropical rainforest (1.65). In general, the predicated universal scaling relationship that the mass-based metabolism rate should be proportional to surface area in organisms is not applicable at the leaf-level in plants. Rather, the large slope difference of the relationship between leaf metabolism rate and SLA found among biomes indicates that the strength of the selective forces driving the scaling relationship is different among the biomes. The result basically suggests the importance of increasing SLA to plant carbon gain in stressful environments and to carbon loss in favorable habitats, and therefore has an important implication for survival strategies of plants in different biomes.

  5. Respiration-based monitoring of metabolic rate following cold-exposure in two invasive Anoplophora species depending on acclimation regime.

    Science.gov (United States)

    Javal, M; Roques, A; Roux, G; Laparie, M

    2017-11-09

    The Asian andCitrus longhorned beetles, Anoplophora glabripennis (ALB) and A. chinensis (CLB) respectively, are two closely related invasive species with overlapping native ranges. Although both species have rather similar biological characteristics, they differ in their invasion patterns. ALB shows numerous, but local, outbreaks in urban areas of North-East America, Western andCentral Europe, whereas CLB has colonized a large part of Northern Italy. Temperature is pivotal in setting distribution limits of ectotherms. Low temperature may be limiting for larvae since they are the main overwintering stage for both species. To investigate whether differential cold tolerance may contribute to setting the respective limits of the range invaded by each species, we monitored larval metabolic rate before and after exposure to a one-week ecologically relevant moderate cold stress (-2/+2°C, 14/10h). We tested two distinctive fluctuating regimes before the cold exposure to check whether larval acclimation significantly altered their cold tolerance. Survival was high in all conditions for both species. Visual examination showed temporary locomotor inactivity during the stress but respiration rates were not altered after the stress suggesting that larvae could rapidly resume their initial metabolic activity. The respiration rate was globally higher in ALB than in CLB. Together, these results tend to indicate that both species have similar tolerance to the moderate cold stress tested, but also that ALB may be better at maintaining metabolic activity at cold than CLB. These observed differences could affect phenology in both species and in turn their establishment potential. Copyright © 2017. Published by Elsevier Inc.

  6. Can We Rely on Predicted Basal Metabolic Rate in Patients With Intestinal Failure on Home Parenteral Nutrition?

    DEFF Research Database (Denmark)

    Andersen, Anders Skallerup; Pedersen, Louis Nygaard; Olesen, Søren Schou

    2017-01-01

    evaluated the accuracy of predicted BMR in clinically stable patients with IF dependent on home parenteral nutrition (HPN). METHODS: In total, 103 patients with IF were included. We used indirect calorimetry for assessment of BMR and calculated predicted BMR using different equations based on anthropometric......BACKGROUND AND AIMS: Intestinal failure (IF) is a serious and common complication of short bowel syndrome with patients depending on parental nutrition (PN) support. Effective nutrition management requires an accurate estimation of the patient's basal metabolic rate (BMR) to avoid underfeeding...

  7. Multi-Criteria Indicator for Sustainability Rating in Suppliers of the Oil and Gas Industries in Brazil

    Directory of Open Access Journals (Sweden)

    José Felipe Figueiredo Barata

    2014-02-01

    Full Text Available The necessity of sustainability evaluation is rapidly growing alongside the expansion of civilization. Likewise, the supply chain suitability improvement is a need that has arisen in the petroleum industry, especially as it is responsible for the most part of CO2 emissions in the atmosphere. The modeling of this kind of problem deals with multiple criteria evaluations. This paper proposes an original multiple-criteria based approach to classifying the degree of organizational sustainability. This proposal was applied to evaluate a representative set of companies, which are suppliers of the Brazilian petroleum industry. The data collection was supported by a questionnaire. The results highlight that the studied companies have not yet reached an advanced level of maturity in the sustainability context. In a comprehensive vision of sustainability based on Triple Bottom Line (TBL, these companies are either in the initial stage or in the implementation phase of the sustainability practices.

  8. Extraction of elementary rate constants from global network analysis of E. coli central metabolism

    Directory of Open Access Journals (Sweden)

    Broderick Gordon

    2008-05-01

    Full Text Available Abstract Background As computational performance steadily increases, so does interest in extending one-particle-per-molecule models to larger physiological problems. Such models however require elementary rate constants to calculate time-dependent rate coefficients under physiological conditions. Unfortunately, even when in vivo kinetic data is available, it is often in the form of aggregated rate laws (ARL that do not specify the required elementary rate constants corresponding to mass-action rate laws (MRL. There is therefore a need to develop a method which is capable of automatically transforming ARL kinetic information into more detailed MRL rate constants. Results By incorporating proteomic data related to enzyme abundance into an MRL modelling framework, here we present an efficient method operating at a global network level for extracting elementary rate constants from experiment-based aggregated rate law (ARL models. The method combines two techniques that can be used to overcome the difficult properties in parameterization. The first, a hybrid MRL/ARL modelling technique, is used to divide the parameter estimation problem into sub-problems, so that the parameters of the mass action rate laws for each enzyme are estimated in separate steps. This reduces the number of parameters that have to be optimized simultaneously. The second, a hybrid algebraic-numerical simulation and optimization approach, is used to render some rate constants identifiable, as well as to greatly narrow the bounds of the other rate constants that remain unidentifiable. This is done by incorporating equality constraints derived from the King-Altman and Cleland method into the simulated annealing algorithm. We apply these two techniques to estimate the rate constants of a model of E. coli glycolytic pathways. The simulation and statistical results show that our innovative method performs well in dealing with the issues of high computation cost, stiffness, local

  9. Physical mechanism or evolutionary trade-off? Factors dictating the relationship between metabolic rate and ambient temperature in carabid beetles.

    Science.gov (United States)

    Gudowska, Agnieszka; Schramm, Bartosz W; Czarnoleski, Marcin; Kozłowski, Jan; Bauchinger, Ulf

    2017-08-01

    The tight association between ambient temperature (T) and metabolic rate (MR) is a common occurrence in ectotherms, but the determinants of this association are not fully understood. This study examined whether the relationship between MR and T is the same among individuals, as predicted by the Universal Temperature Dependence hypothesis, or whether this relationship differs between them. We used flow-through respirometry to measure standard MR and to determine gas exchange patterns for 111 individuals of three Carabidae species which differ in size (Abax ovalis, Carabus linnei and C. coriaceus), exposed to four different temperatures (ten individuals of each species measured at 6, 11, 16 and 21°C). We found a significant interaction between ln body mass and the inverse of temperature, indicating that in a given species, the effect of temperature on MR was weaker in larger individuals than in smaller individuals. Overall, this finding shows that the thermal dependence of MR is not body mass invariant. We observed three types of gas exchange patterns among beetles: discontinuous, cyclic and continuous. Additionally, the appearance of these patterns was associated with MR and T. Evolution in diverse terrestrial environments could affect diverse ventilation patterns, which accommodate changes in metabolism in response to temperature variation. In conclusion, explaining the variance in metabolism only through fundamental physical laws of thermodynamics, as predicted by the Universal Temperature Dependence hypothesis, appears to oversimplify the complexity of nature, ignoring evolutionary trade-offs that should be taken into account in the temperature - metabolism relationship. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Towards a Sustainable Urban Metabolism: Algae-to-Energy Systems as Clean Cycles in the Urban Water Chain

    OpenAIRE

    Menger-Krug, Eve

    2013-01-01

    This study includes an analysis of the urban water chain in Germany (water supply, wastewater and sludge management); followed by an analysis of the integration of algae systems on the level of wastewater treatment plants. Then, the scope of the study is extended to put the results in context of the urban metabolism. The relevance of the urban water chain - with and without algae - for the urban energy balance and the urban flows of nutrients and anthropogenic micropollutants is assessed.

  11. Lack of evolvability in self-sustaining autocatalytic networks constraints metabolism-first scenarios for the origin of life.

    Science.gov (United States)

    Vasas, Vera; Szathmáry, Eörs; Santos, Mauro

    2010-01-26

    A basic property of life is its capacity to experience Darwinian evolution. The replicator concept is at the core of genetics-first theories of the origin of life, which suggest that self-replicating oligonucleotides or their similar ancestors may have been the first "living" systems and may have led to the evolution of an RNA world. But problems with the nonenzymatic synthesis of biopolymers and the origin of template replication have spurred the alternative metabolism-first scenario, where self-reproducing and evolving proto-metabolic networks are assumed to have predated self-replicating genes. Recent theoretical work shows that "compositional genomes" (i.e., the counts of different molecular species in an assembly) are able to propagate compositional information and can provide a setup on which natural selection acts. Accordingly, if we stick to the notion of replicator as an entity that passes on its structure largely intact in successive replications, those macromolecular aggregates could be dubbed "ensemble replicators" (composomes) and quite different from the more familiar genes and memes. In sharp contrast with template-dependent replication dynamics, we demonstrate here that replication of compositional information is so inaccurate that fitter compositional genomes cannot be maintained by selection and, therefore, the system lacks evolvability (i.e., it cannot substantially depart from the asymptotic steady-state solution already built-in in the dynamical equations). We conclude that this fundamental limitation of ensemble replicators cautions against metabolism-first theories of the origin of life, although ancient metabolic systems could have provided a stable habitat within which polymer replicators later evolved.

  12. The mTORC2/PKC pathway sustains compensatory insulin secretion of pancreatic β cells in response to metabolic stress.

    Science.gov (United States)

    Xie, Yun; Cui, Canqi; Nie, Aifang; Wang, Yan; Ni, Qicheng; Liu, Yun; Yin, Qinglei; Zhang, Hongli; Li, Yong; Wang, Qidi; Gu, Yanyun; Ning, Guang

    2017-08-01

    Compensation of the pancreatic β cell functional mass in response to metabolic stress is key to the pathogenesis of Type 2 Diabetes. The mTORC2 pathway governs fuel metabolism and β cell functional mass. It is unknown whether mTORC2 is required for regulating metabolic stress-induced β cell compensation. We challenged four-week-old β-cell-specific Rictor (a key component of mTORC2)-knockout mice with a high fat diet (HFD) for 4weeks and measured metabolic and pancreatic morphological parameters. We performed ex vivo experiments to analyse β cell insulin secretion and electrophysiology characteristics. Adenoviral-mediated overexpression and lentiviral-ShRNA-mediated knocking down proteins were applied in Min6 cells and cultured primary mouse islets. βRicKO mice showed a significant glucose intolerance and a reduced plasma insulin level and an unchanged level β cell mass versus the control mice under HFD. A HFD or palmitate treatment enhanced both glucose-induced insulin secretion (GIIS) and the PMA (phorbol 12-myristate 13-acetate)-induced insulin secretion in the control islets but not in the βRicKO islets. The KO β cells showed similar glucose-induced Ca2+ influx but lower membrane capacitance increments versus the control cells. The enhanced mTORC2/PKC proteins levels in the control HFD group were ablated by Rictor deletion. Replenishing PKCα by overexpression of PKCα-T638D restored the defective GIIS in βRicKO islets. The mTORC2/Rictor pathway modulates β cell compensatory GIIS under nutrient overload mediated by its phosphorylation of PKCα. This study suggests that the mTORC2/PKC pathway in β cells is involved in the pathogenesis of T2D. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Controlling the feed rate of glucose and propanol for the enhancement of erythromycin production and exploration of propanol metabolism fate by quantitative metabolic flux analysis.

    Science.gov (United States)

    Chen, Yong; Huang, Mingzhi; Wang, Zejian; Chu, Ju; Zhuang, Yingping; Zhang, Siliang

    2013-10-01

    In this paper, several different fermentation experiments were designed to address whether modulating glucose and propanol feeds could benefit the production level of erythromycin during pilot plant (30 L) fermentation. Results showed that glucose feed rate (determined by a set high or low culture pH) had no effect on erythromycin production, indicating that glucose was not the limiting factor for erythromycin biosynthesis under these conditions. It was found that decreasing glucose feed could stimulate the consumption of propanol, and the high erythromycin production (12.49 ± 0.50 mg ml⁻¹) was achieved by controlling the feed rates of glucose and propanol. The quantitative metabolic flux analysis disclosed that high propanol consumption increased the pool size of propionyl-CoA (~2.147 mmol g⁻¹ day⁻¹) and methylmalonyl-CoA (~1.708 mmol g⁻¹ day⁻¹). It was also found that 45-77 % of the propanol went into the TCA cycle which strengthened the conclusion that blocking the propionate pathway to TCA cycle could lead to a significant increase in erythromycin production in carbohydrate-based media (Reeves et al. Ind Microbiol Biotechnol 7:600-609, 2006). In addition, the results also suggested that a relative low intracellular ATP level resulting from low glucose feed did not limit the erythromycin biosynthesis, and a relatively high NADPH should be beneficial for erythromycin biosynthesis.

  14. Effects of intraspecific variation in reproductive traits, pectoral fin use and burst swimming on metabolic rates and swimming performance in the Trinidadian guppy (Poecilia reticulata)

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Banet, Amanda I.; Christensen, Rune Haubo Bojesen

    2013-01-01

    of reproductive traits, pectoral fin use and burse-assisted swimming on swimming metabolic rate, standard metabolic rate (MO2std) and prolonged swimming performance (Ucrit). Reproductive traits included reproductive allocation and pregnancy stage, the former defined as the mass of the reproductive tissues divided......There is considerable intraspecific variation in metabolic rates and locomotor performance in aquatic ectothermic vertebrates; however, the mechanistic basis remains poorly understood. Using pregnant Trinidadian guppies (Poecilia reticulata), a livebearing teleost, we examined the effects...... by the total body mass. Results showed that the metabolic rate increased curvilinearly with swimming speed. The slope of the relationship was used as an index of swimming cost. There was no evidence that reproductive traits correlated with swimming cost, MO2std or Ucrit. In contrast, data revealed strong...

  15. Metabolic rate and cardiorespiratory response during hybrid cycling versus handcycling at equal subjective exercise intensity levels in people with spinal cord injury

    NARCIS (Netherlands)

    Bakkum, Arjan J. T.; de Groot, Sonja; Onderwater, Mark Q.; de Jong, Jelle; Janssen, Thomas W. J.

    2014-01-01

    Objective: To compare the metabolic rate and cardiorespiratory response during hybrid cycling versus handcycling at equal subjective exercise intensity levels in people with spinal cord injury (SCI). Design: Cross-sectional study. Setting: Amsterdam Rehabilitation Research Centre vertical bar Reade,

  16. Flower vs. leaf feeding by Pieris brassicae: glucosinolate-rich flower tissues are preferred and sustain higher growth rate.

    Science.gov (United States)

    Smallegange, R C; van Loon, J J A; Blatt, S E; Harvey, J A; Agerbirk, N; Dicke, M

    2007-10-01

    Interactions between butterflies and caterpillars in the genus Pieris and plants in the family Brassicaceae are among the best explored in the field of insect-plant biology. However, we report here for the first time that Pieris brassicae, commonly assumed to be a typical folivore, actually prefers to feed on flowers of three Brassica nigra genotypes rather than on their leaves. First- and second-instar caterpillars were observed to feed primarily on leaves, whereas late second and early third instars migrated via the small leaves of the flower branches to the flower buds and flowers. Once flower feeding began, no further leaf feeding was observed. We investigated growth rates of caterpillars having access exclusively to either leaves of flowering plants or flowers. In addition, we analyzed glucosinolate concentrations in leaves and flowers. Late-second- and early-third-instar P. brassicae caterpillars moved upward into the inflorescences of B. nigra and fed on buds and flowers until the end of the final (fifth) instar, after which they entered into the wandering stage, leaving the plant in search of a pupation site. Flower feeding sustained a significantly higher growth rate than leaf feeding. Flowers contained levels of glucosinolates up to five times higher than those of leaves. Five glucosinolates were identified: the aliphatic sinigrin, the aromatic phenylethylglucosinolate, and three indole glucosinolates: glucobrassicin, 4-methoxyglucobrassicin, and 4-hydroxyglucobrassicin. Tissue type and genotype were the most important factors affecting levels of identified glucosinolates. Sinigrin was by far the most abundant compound in all three genotypes. Sinigrin, 4-hydroxyglucobrassicin, and phenylethylglucosinolate were present at significantly higher levels in flowers than in leaves. In response to caterpillar feeding, sinigrin levels in both leaves and flowers were significantly higher than in undamaged plants, whereas 4-hydroxyglucobrassicin leaf levels were

  17. High diving metabolic rate indicated by high-speed transit to depth in negatively buoyant long-finned pilot whales.

    Science.gov (United States)

    Aoki, Kagari; Sato, Katsufumi; Isojunno, Saana; Narazaki, Tomoko; Miller, Patrick J O

    2017-10-15

    To maximize foraging duration at depth, diving mammals are expected to use the lowest cost optimal speed during descent and ascent transit and to minimize the cost of transport by achieving neutral buoyancy. Here, we outfitted 18 deep-diving long-finned pilot whales with multi-sensor data loggers and found indications that their diving strategy is associated with higher costs than those of other deep-diving toothed whales. Theoretical models predict that optimal speed is proportional to (basal metabolic rate/drag)1/3 and therefore to body mass0.05 The transit speed of tagged animals (2.7±0.3 m s-1) was substantially higher than the optimal speed predicted from body mass (1.4-1.7 m s-1). According to the theoretical models, this choice of high transit speed, given a similar drag coefficient (median, 0.0035) to that in other cetaceans, indicated greater basal metabolic costs during diving than for other cetaceans. This could explain the comparatively short duration (8.9±1.5 min) of their deep dives (maximum depth, 444±85 m). Hydrodynamic gliding models indicated negative buoyancy of tissue body density (1038.8±1.6 kg m-3, ±95% credible interval, CI) and similar diving gas volume (34.6±0.6 ml kg-1, ±95% CI) to those in other deep-diving toothed whales. High diving metabolic rate and costly negative buoyancy imply a 'spend more, gain more' strategy of long-finned pilot whales, differing from that in other deep-diving toothed whales, which limits the costs of locomotion during foraging. We also found that net buoyancy affected the optimal speed: high transit speeds gradually decreased during ascent as the whales approached neutral buoyancy owing to gas expansion. © 2017. Published by The Company of Biologists Ltd.

  18. Effect of Temperature on Precipitation Rate of Calcium Carbonate Produced through Microbial Metabolic Process of Bio Materials

    Directory of Open Access Journals (Sweden)

    Prima Yane Putri

    2016-09-01

    Full Text Available Concrete is the most widely used construction material in civil engineering. But plain concrete is a brittle material and has little resistance to cracking. The cracking in concrete promotes deterioration such as the corrosion of reinforcing rebar, therefore, repair in filling the crack is often carried out. Recently, repair methods using bio-based materials associated with microbial metabolic processes leading to precipitation of calcium carbonate have been intensively studied. In this study, influencing factors on the precipitation rate depending on the constituents of bio-based material comprising yeast, glucose and calcium acetate mixed in tris buffer solution was examined for improving the rate of initial reactions. In addition, effect of temperature change on the amount of calcium carbonate precipitation was also investigated. The precipitates were identified by X-ray diffraction. It was shown that the increase of temperature lead to a change on calcium carbonate precipitation and caused the pH decrease under 7.0.

  19. Designing safer chemicals: Predicting the rates of metabolism of halogenated alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Yin, H.; Anders, M.W.; Higgins, L. [Univ. of Rochester, NY (United States)

    1995-11-21

    A computational model is presented that can be used as a tool in the design of safer chemicals. This model predicts that rate of hydrogen-atom abstraction by cytochrome P450 enzymes. Excellent correlations between biotransformation rates and the calculated activation energies ({Delta}H{sub act}) of the cytochrome P450-mediated hydrogen-atom abstractions were obtained for the in vitro biotransformation of six halogenated alkanes (1-fluoro-1,1,1,2,2-tetrachloroethane, 1,1,1,2-tetrafluoro-2-chloroethane, 1,1,1,2,2-pentafluoroethane, and 2-bromo-2-chloro-1,1,1-trifluoroethane) with both rat and human enzyme preparations: (rate, human CYP2E1) = 44.99 - 1.79 ({Delta}H{sub act}), r{sup 2} = 0.86; In (rate, human Cyp2E1)= 46399 -1.77 ({Delta}H{sub act}), r{sup 2} = 0.97 (rates are in nmol of product per min per nmol of cytochrome P450 and energies are in kcal/mol). Correlations were also obtained for five inhalation anesthetics (enflurane, sevoflurane, desflurane, methoxyflurane, and isoflurane) for both in vivo and in vitro data have been shown to agree in any species. The model presented herein provides an archetype for the methodology that may be used in the future design of safer chemicals, particularly hydrochlorofluorocarbons and inhalation anesthetics. 41 refs., 1 fig., 2 tabs.

  20. Dietary lipid saturation influences environmental temperature preference but not resting metabolic rate in the Djungarian Hamster (Phodopus sungorus).

    Science.gov (United States)

    Pannorfi, Ryan; Zee, Barry M; Vatnick, Itzick; Berner, Nancy; Hiebert, Sara M

    2012-01-01

    Heterothermic rodents increase self-selection of diets rich in polyunsaturated fatty acids (PUFAs) when exposed to cold, short days, or short-day melatonin profiles, and Djungarian hamsters (Phodopus sungorus) do so in long days in response to cold exposure alone. To determine whether Djungarian hamsters are also capable of selecting a thermal environment in response to dietary lipid composition, continuously normothermic hamsters were fed either a PUFA-rich diet or a diet rich in saturated fatty acids (SFAs) for 6-10 wk and given a choice of thermal environments. As predicted, SFA-fed hamsters were more likely than PUFA-fed hamsters to occupy the single heated corner of their cage ([Formula: see text]) and were most likely to show this diet-related difference in behavior when T(a) fell within the thermal neutral zone. Respirometry revealed no effect of diet on whole-animal or mass-specific resting metabolic rate or on lower critical temperature. The results are more consistent with the homeoviscous adaptation hypothesis, which predicts that organisms should make physiological and/or behavioral adjustments that preserve membrane fluidity within a relatively small range, than with the membrane pacemaker hypothesis, which predicts that high PUFA content in membrane phospholipids should increase basal metabolic rate.

  1. The effects of laboratory housing and spatial enrichment on brain size and metabolic rate in the eastern mosquitofish, Gambusia holbrooki

    Directory of Open Access Journals (Sweden)

    Mischa P. Turschwell

    2016-03-01

    Full Text Available It has long been hypothesised that there is a functional correlation between brain size and metabolic rate in vertebrates. The present study tested this hypothesis in wild-caught adult mosquitofish Gambusia holbrooki by testing for an intra-specific association between resting metabolic rate (RMR and brain size while controlling for variation in body size, and through the examination of the effects of spatial enrichment and laboratory housing on body mass-independent measures of brain size and RMR. Controlling for body mass, there was no relationship between brain size and RMR in wild-caught fish. Contrary to predictions, spatial enrichment caused a decrease in mass-independent brain size, highlighting phenotypic plasticity in the adult brain. As expected, after controlling for differences in body size, wild-caught fish had relatively larger brains than fish that had been maintained in the laboratory for a minimum of six weeks, but wild-caught fish also had significantly lower mass-independent RMR. This study demonstrates that an organisms' housing environment can cause significant plastic changes to fitness related traits including brain size and RMR. We therefore conclude that current standard laboratory housing conditions may cause captive animals to be non-representative of their wild counterparts, potentially undermining the transferability of previous laboratory-based studies of aquatic ectothermic vertebrates to wild populations.

  2. The effects of laboratory housing and spatial enrichment on brain size and metabolic rate in the eastern mosquitofish, Gambusia holbrooki.

    Science.gov (United States)

    Turschwell, Mischa P; White, Craig R

    2016-01-21

    It has long been hypothesised that there is a functional correlation between brain size and metabolic rate in vertebrates. The present study tested this hypothesis in wild-caught adult mosquitofish Gambusia holbrooki by testing for an intra-specific association between resting metabolic rate (RMR) and brain size while controlling for variation in body size, and through the examination of the effects of spatial enrichment and laboratory housing on body mass-independent measures of brain size and RMR. Controlling for body mass, there was no relationship between brain size and RMR in wild-caught fish. Contrary to predictions, spatial enrichment caused a decrease in mass-independent brain size, highlighting phenotypic plasticity in the adult brain. As expected, after controlling for differences in body size, wild-caught fish had relatively larger brains than fish that had been maintained in the laboratory for a minimum of six weeks, but wild-caught fish also had significantly lower mass-independent RMR. This study demonstrates that an organisms' housing environment can cause significant plastic changes to fitness related traits including brain size and RMR. We therefore conclude that current standard laboratory housing conditions may cause captive animals to be non-representative of their wild counterparts, potentially undermining the transferability of previous laboratory-based studies of aquatic ectothermic vertebrates to wild populations. © 2016. Published by The Company of Biologists Ltd.

  3. Size dependence in non-sperm ejaculate production is reflected in daily energy expenditure and resting metabolic rate.

    Science.gov (United States)

    Friesen, Christopher R; Powers, Donald R; Copenhaver, Paige E; Mason, Robert T

    2015-05-01

    The non-sperm components of an ejaculate, such as copulatory plugs, can be essential to male reproductive success. But the costs of these ejaculate components are often considered trivial. In polyandrous species, males are predicted to increase energy allocation to the production of non-sperm components, but this allocation is often condition dependent and the energetic costs of their production have never been quantified. Red-sided garter snakes (Thamnophis sirtalis parietalis) are an excellent model with which to quantify the energetic costs of non-sperm components of the ejaculate as they exhibit a dissociated reproductive pattern in which sperm production is temporally disjunct from copulatory plug production, mating and plug deposition. We estimated the daily energy expenditure and resting metabolic rate of males after courtship and mating, and used bomb calorimetry to estimate the energy content of copulatory plugs. We found that both daily energy expenditure and resting metabolic rate were significantly higher in small mating males than in courting males, and a single copulatory plug without sperm constitutes 5-18% of daily energy expenditure. To our knowledge, this is the first study to quantify the energetic expense of size-dependent ejaculate strategies in any species. © 2015. Published by The Company of Biologists Ltd.

  4. Thyroxine-induced changes in metabolic rate and cytochrome oxidase activity in Thamnophis sirtalis: effects of nutritional status.

    Science.gov (United States)

    Etheridge, K

    1993-07-01

    The effects of nutritional status on thyroxine-induced changes in standard metabolic rate (SMR), and the activity of hepatic cytochrome oxidase were examined in the garter snake Thamnophis sirtalis. Twelve snakes were fed ad libitum, and 12 more were fed a maintenance diet, which was half as many fish per gram of body weight as that eaten by ad libitum snakes. Snakes in the first group gained weight during the 3-week treatment, while individual snakes in the second group either maintained their original weight or showed a slight loss (less than 10%). Within each diet treatment, half of the snakes received a 5-mg thyroxine (T4) pellet implant, and half received placebo implants. Plasma [T4] was unchanged by treatment. Plasma [T3] was elevated in T4-supplemented snakes fed ad libitum, but the difference was not statistically significant (P = 0.09). Standard metabolic rate and cytochrome oxidase activity at 25 degrees were increased significantly (34 and 24%, respectively) only in the T4-supplemented snakes on the ad libitum diet. Thus, T. sirtalis must be in a positive energy balance for thyroid hormones to have an effect on SMR or hepatic cytochrome oxidase activity.

  5. Differences in the metabolic rates of exploited and unexploited fish populations: a signature of recreational fisheries induced evolution?

    Directory of Open Access Journals (Sweden)

    Jan-Michael Hessenauer

    Full Text Available Non-random mortality associated with commercial and recreational fisheries have the potential to cause evolutionary changes in fish populations. Inland recreational fisheries offer unique opportunities for the study of fisheries induced evolution due to the ability to replicate study systems, limited gene flow among populations, and the existence of unexploited reference populations. Experimental research has demonstrated that angling vulnerability is heritable in Largemouth Bass Micropterus salmoides, and is correlated with elevated resting metabolic rates (RMR and higher fitness. However, whether such differences are present in wild populations is unclear. This study sought to quantify differences in RMR among replicated exploited and unexploited populations of Largemouth Bass. We collected age-0 Largemouth Bass from two Connecticut drinking water reservoirs unexploited by anglers for almost a century, and two exploited lakes, then transported and reared them in the same pond. Field RMR of individuals from each population was quantified using intermittent-flow respirometry. Individuals from unexploited reservoirs had a significantly higher mean RMR (6% than individuals from exploited populations. These findings are consistent with expectations derived from artificial selection by angling on Largemouth Bass, suggesting that recreational angling may act as an evolutionary force influencing the metabolic rates of fishes in the wild. Reduced RMR as a result of fisheries induced evolution may have ecosystem level effects on energy demand, and be common in exploited recreational populations globally.

  6. Relationship of metal metabolism to vascular disease mortality rates in Texas.

    Science.gov (United States)

    Dawson, E B; Frey, M J; Moore, T D; McGanity, W J

    1978-07-01

    The annual mortality rates for 1968 of six types of cardiovascular diseases among those persons over 45 years of age in 24 Texas communities were compared with respective community drinking water and urine metal levels of calcium, magnesium, potassium, lithium, strontium, and silicon. Numerous inverse correlations were found between mortality rates and the levels of various metals in both drinking water and urine. Positive correlations were also observed between several of the mortality rates and the ratio of the concentration of sodium to that of the other metals in both water and urine. Mean community urinary levels of lithium, magnesium, strontium, and silicon showed a direct correlation to the levels of exposure via the drinking water. The results of this study suggest that calcium, magnesium, lithium strontium, and silicon may protect against cardiovascular mortality; possibly, by competing with sodium and potassium for transport in the intestinal lumen, increasing excretion of sodium, or other mechanism.

  7. Heart rate variability analysed by Poincaré plot in patients with metabolic syndrome.

    Science.gov (United States)

    Kubičková, Alena; Kozumplík, Jiří; Nováková, Zuzana; Plachý, Martin; Jurák, Pavel; Lipoldová, Jolana

    2016-01-01

    The SD1 and SD2 indexes (standard deviations in two orthogonal directions of the Poincaré plot) carry similar information to the spectral density power of the high and low frequency bands but have the advantage of easier calculation and lesser stationarity dependence. ECG signals from metabolic syndrome (MetS) and control group patients during tilt table test under controlled breathing (20 breaths/minute) were obtained. SD1, SD2, SDRR (standard deviation of RR intervals) and RMSSD (root mean square of successive differences of RR intervals) were evaluated for 31 control group and 33 MetS subjects. Statistically significant lower values were observed in MetS patients in supine position (SD1: p=0.03, SD2: p=0.002, SDRR: p=0.006, RMSSD: p=0.01) and during tilt (SD2: p=0.004, SDRR: p=0.007). SD1 and SD2 combining the advantages of time and frequency domain methods, distinguish successfully between MetS and control subjects. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Encystment of parasitic freshwater pearl mussel (Margaritifera margaritifera) larvae coincides with increased metabolic rate and haematocrit in juvenile brown trout (Salmo trutta).

    Science.gov (United States)

    Filipsson, Karl; Brijs, Jeroen; Näslund, Joacim; Wengström, Niklas; Adamsson, Marie; Závorka, Libor; Österling, E Martin; Höjesjö, Johan

    2017-04-01

    Gill parasites on fish are likely to negatively influence their host by inhibiting respiration, oxygen transport capacity and overall fitness. The glochidia larvae of the endangered freshwater pearl mussel (FPM, Margaritifera margaritifera (Linnaeus, 1758)) are obligate parasites on the gills of juvenile salmonid fish. We investigated the effects of FPM glochidia encystment on the metabolism and haematology of brown trout (Salmo trutta Linnaeus, 1758). Specifically, we measured whole-animal oxygen uptake rates at rest and following an exhaustive exercise protocol using intermittent flow-through respirometry, as well as haematocrit, in infested and uninfested trout. Glochidia encystment significantly affected whole-animal metabolic rate, as infested trout exhibited higher standard and maximum metabolic rates. Furthermore, glochidia-infested trout also had elevated levels of haematocrit. The combination of an increased metabolism and haematocrit in infested fish indicates that glochidia encystment has a physiological effect on the trout, perhaps as a compensatory response to the potential respiratory stress caused by the glochidia. When relating glochidia load to metabolism and haematocrit, fish with low numbers of encysted glochidia were the ones with particularly elevated metabolism and haematocrit. Standard metabolic rate decreased with substantial glochidia loads towards levels similar to those of uninfested fish. This suggests that initial effects visible at low levels of encystment may be countered by additional physiological effects at high loads, e.g. potential changes in energy utilization, and also that high numbers of glochidia may restrict oxygen uptake by the gills.

  9. Metabolic modeling of energy balances in Mycoplasma hyopneumoniae shows that pyruvate addition increases growth rate

    NARCIS (Netherlands)

    Kamminga, Tjerko; Slagman, Simen Jan; Bijlsma, Jetta J.E.; Martins dos Santos, Vitor A.P.; Suarez-Diez, Maria; Schaap, Peter J.

    2017-01-01

    Mycoplasma hyopneumoniae is cultured on large-scale to produce antigen for inactivated whole-cell vaccines against respiratory disease in pigs. However, the fastidious nutrient requirements of this minimal bacterium and the low growth rate make it challenging to reach sufficient biomass yield for

  10. Metabolic rates, enzyme activities and chemical compositions of some deep-sea pelagic worms, particularly Nectonemertes mirabilis (Nemertea; Hoplonemertinea) and Poeobius meseres (Annelida; Polychaeta)

    Science.gov (United States)

    Thuese