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Sample records for measured metabolic rates

  1. Comparison between Medgem and Deltatrac resting metabolic rate measurements.

    Science.gov (United States)

    Compher, C; Hise, M; Sternberg, A; Kinosian, B P

    2005-10-01

    The primary aims of this trial were to evaluate the reproducibility of a portable handheld calorimeter (Medgem) in a clinical population, and to compare its measures with a calorimeter in typical use with these patients. Cross-sectional clinical validation study. Outpatient Clinical Research Center. A total of 24 stable home nutrition support patients. In random order three measures of resting metabolic rate (RMR) were taken after a 4-h fast, 15 min rest and 2-h abstention from exercise. Two measures were taken with the same Medgem (MG) and one with the traditional calorimeter (Deltatrac). Reproducibility of MG measures and their comparability to a Deltatrac measure were assessed by Bland-Altman analysis, with >+/-250 kcal/day established a priori as a clinically unacceptable error. In addition, disagreement between the two types of measures was defined as greater than 10% difference. The mean difference between two MG measures was -6.8 kcal/day, with limits of agreement between 233 and -247 kcal/day and clinically acceptable. The mean difference between the Deltatrac and mean of two MG measures was -162 kcal/day, with limits of agreement between 577 and -253 kcal/day and clinically unacceptable. In all, 80% of the repeated MG RMR measures agreed within 10%, and the mean MG reading agreed with the Deltatrac in 60% of cases. RMR obtained using the MG calorimeter has an acceptable degree of reproducibility, and is acceptable to patients. The MG measures, however, are frequently lower than traditional measures and require further validation prior to application to practice in this vulnerable patient group.

  2. Experimental sources of variation in avian energetics: estimated basal metabolic rate decreases with successive measurements.

    Science.gov (United States)

    Jacobs, Paul J; McKechnie, Andrew E

    2014-01-01

    Basal metabolic rate (BMR) is one of the most widely used metabolic variables in endotherm ecological and evolutionary physiology. Surprisingly few studies have investigated how BMR is influenced by experimental and analytical variables over and above the standardized conditions required for minimum normothermic resting metabolism. We tested whether avian BMR is affected by habituation to the conditions experienced during laboratory gas exchange measurements by measuring BMR five times in succession in budgerigars (Melopsittacus undulatus) housed under constant temperature and photoperiod. Both the magnitude and the variability of BMR decreased significantly with repeated measurements, from 0.410 ± 0.092 W (n = 9) during the first measurement to 0.285 ± 0.042 W (n = 9) during the fifth measurement. Thus, estimated BMR decreased by ∼30% within individuals solely on account of the number of times they had previously experienced the experimental conditions. The most likely explanation for these results is an attenuation with repeated exposure of the acute stress response induced by birds being handled and placed in respirometry chambers. Our data suggest that habituation to experimental conditions is potentially an important determinant of observed BMR, and this source of variation needs to be taken into account in future studies of metabolic variation among individuals, populations, and species.

  3. Exploration of Energy Metabolism in the Mouse Using Indirect Calorimetry: Measurement of Daily Energy Expenditure (DEE) and Basal Metabolic Rate (BMR).

    Science.gov (United States)

    Meyer, Carola W; Reitmeir, Peter; Tschöp, Matthias H

    2015-09-01

    Current comprehensive mouse metabolic phenotyping involves studying energy balance in cohorts of mice via indirect calorimetry, which determines heat release from changes in respiratory air composition. Here, we describe the measurement of daily energy expenditure (DEE) and basal metabolic rate (BMR) in mice. These well-defined metabolic descriptors serve as meaningful first-line read-outs for metabolic phenotyping and should be reported when exploring energy expenditure in mice. For further guidance, the issue of appropriate sample sizes and the frequency of sampling of metabolic measurements is also discussed. Copyright © 2015 John Wiley & Sons, Inc.

  4. 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

  5. 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.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

    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

  7. 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 (BMR was estimated for each group using the Harris-Benedict (H-B), Schofield, or Cunningham 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 BMR values estimated using the H-B and Cunningham equations were different significantly from the measured BMR (p 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.

  8. 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.

  9. Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose

    International Nuclear Information System (INIS)

    Ackermann, R.F.; Lear, J.L.

    1989-01-01

    We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered [ 18 F]fluorodeoxyglucose (FDG) and [ 14 C]-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the 14 C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the 14 C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum

  10. Prediction of work metabolism from heart rate measurements in forest work: some practical methodological issues.

    Science.gov (United States)

    Dubé, Philippe-Antoine; Imbeau, Daniel; Dubeau, Denise; Auger, Isabelle; Leone, Mario

    2015-01-01

    Individual heart rate (HR) to workload relationships were determined using 93 submaximal step-tests administered to 26 healthy participants attending physical activities in a university training centre (laboratory study) and 41 experienced forest workers (field study). Predicted maximum aerobic capacity (MAC) was compared to measured MAC from a maximal treadmill test (laboratory study) to test the effect of two age-predicted maximum HR Equations (220-age and 207-0.7 × age) and two clothing insulation levels (0.4 and 0.91 clo) during the step-test. Work metabolism (WM) estimated from forest work HR was compared against concurrent work V̇O2 measurements while taking into account the HR thermal component. Results show that MAC and WM can be accurately predicted from work HR measurements and simple regression models developed in this study (1% group mean prediction bias and up to 25% expected prediction bias for a single individual). Clothing insulation had no impact on predicted MAC nor age-predicted maximum HR equations. Practitioner summary: This study sheds light on four practical methodological issues faced by practitioners regarding the use of HR methodology to assess WM in actual work environments. More specifically, the effect of wearing work clothes and the use of two different maximum HR prediction equations on the ability of a submaximal step-test to assess MAC are examined, as well as the accuracy of using an individual's step-test HR to workload relationship to predict WM from HR data collected during actual work in the presence of thermal stress.

  11. 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...

  12. Implications of progesterone metabolism in MA-10 cells for accurate measurement of the rate of steroidogenesis

    NARCIS (Netherlands)

    F.F.G. Rommerts (Focko); S.R. King (Steven); P.N. Span (Paul)

    2001-01-01

    textabstractIn virtually all studies with MA-10 cells, progesterone RIAs have been used to measure steroid synthesis. To test whether progesterone is a stable end product, we investigated the metabolism of added tritiated progesterone and pregnenolone in MA-10 cells over a period

  13. Implications of progesterone metabolism in MA-10 cells for accurate measurement of the rate of steroidogenesis.

    NARCIS (Netherlands)

    Rommerts, F.F.; King, S.R.; Span, P.N.

    2001-01-01

    In virtually all studies with MA-10 cells, progesterone RIAs have been used to measure steroid synthesis. To test whether progesterone is a stable end product, we investigated the metabolism of added tritiated progesterone and pregnenolone in MA-10 cells over a period of 3 h. Steroids were then

  14. Measurement of the carrying capacity of benthic habitats using a metabolic-rate based index.

    Science.gov (United States)

    Edgar, G J

    1993-03-01

    Carrying capacities of grazed habitats are typically expressed as numbers or biomass of animals per unit area; however, such parameters are appropriate only when the body size of animals is constant because consumption and other metabolic-rate based parameters such as respiration and production are proportional to body mass raised by a power of ≈0.75 rather than 0 or 1. Habitat carrying levels are therefore better expressed in the form of an index of total community consumption by summing the body masses of individual animals after they have been scaled using a biomass exponent of ≈0.75. A parameter scaled in this way,P 20 , varied in a predictable manner when calculated for the mobile epifaunal assemblages associated with rope fibre habitats placed at marine and estuarine sites;P 20 showed no significant difference between 17 shallow, clear-water sites worldwide, but declined consistently when photosynthesis was reduced.P 20 also did not vary significantly when calculated for the mobile epifaunal communities associated with fourAmphibolis antarctica seagrass habitats in Australia ([Formula: see text] = 100 µg ·g -1 · day -1 ), and reached but did not significantly exceed a ceiling of ≈280 μg · g -1 · day -1 forSargassum plants. These results are consistent with the hypothesis that the production of shallow-water epifaunal communities of grazers is constrained by resource ceilings which can be quantified using metabolic-rate based indices. If this "production ceiling" hypothesis is correct then diffuse competition is generally more important than predation or environmental disturbance in restricting the growth of mobile epifaunal populations.

  15. Phosphorus-31 NMR magnetization transfer measurements of metabolic reaction rates in the rat heart and kidney in vivo

    International Nuclear Information System (INIS)

    Koretsky, A.P.

    1984-01-01

    31 P NMR is a unique tool to study bioenergetics in living cells. The application of magnetization transfer techniques to the measurement of steady-state enzyme reaction rates provides a new approach to understanding the regulation of high energy phosphate metabolism. This dissertation is concerned with the measurement of the rates of ATP synthesis in the rat kidney and of the creatine kinase catalyzed reaction in the rat heart in situ. The theoretical considerations of applying magnetization transfer techniques to intact organs are discussed with emphasis on the problems associated with multiple exchange reactions and compartmentation of reactants. Experimental measurements of the ATP synthesis rate were compared to whole kidney oxygen consumption and Na + reabsorption rates to derive ATP/O values. The problems associated with ATP synthesis rate measurements in kidney, e.g. the heterogeneity of the inorganic phosphate resonance, are discussed and experiments to overcome these problems proposed. In heart, the forward rate through creatine kinase was measured to be larger than the reverse rate. To account for the difference in forward and reverse rates a model is proposed based on the compartmentation of a small pool of ATP

  16. [Measurement of regional cerebral metabolism rate of glucose in patients with Alzheimer's disease in different levels of severity].

    Science.gov (United States)

    Xiao, Shi-fu; Cao, Qiu-yun; Xue, Hai-bo; Liu, Yong-chang; Zuo, Chuan-tao; Jiang, Kai-da; Zhang, Ming-yuan

    2005-11-09

    To measure the changes of regional cerebral metabolism rate of glucose (rCMRglc) in patients with Alzheimer's disease (AD) and explore their value to diagnosis of AD. 10 patients with AD who met the diagnostic criteria of DSM-IV and 10 normal controls (NC) were assessed with (18)F-2-fluoro-deoxy-D-glucose positron emission tomography (PET). The two groups were matched in age, gender and education. The mean total scores of the mini-mental status examination (MMSE) were 16.5 +/- 6.1 for AD and 28.7 +/- 1.6 for NC. The mean total memory quotient of Wechsler Memory Scales (MQ) were 32.3 +/- 19.6 for AD and 93.1 +/- 9.0 for NC. Comparing to NC, the AD groups showed statistically significant decline of rCMRglc in frontal lobe, temporal lobe and the hippocampal formation with decreased rates ranged from 3.3% to 28.4% (P upper and middle frontal gyri, middle temporal gyrus, orbital gyrus and anterior cingulate gyrus, in which areas the metabolism decreased over 20% compared to NC. The hypo-metabolism was correlated to the severity of dementia. Discriminant analysis demonstrated that the variables of right inferior temporal gyrus, left upper temporal gyrus, left hippocampus and right insular lobe were entered into the discriminant functions and the total discriminant accuracy reached 100%. (18)F-FDG PET is a very sensitive tool in measurement of the changes of rCMRglc in patients with AD. The findings show a frontal-temporal type of metabolism in AD patients and suggest that hypo-metabolism in hippocampal formation and temporal lobe is helpful in early detection of AD.

  17. Metabolic rate of spiders (Pardosa prativage) feed on prey species of different diet quality measured by colorimetry

    DEFF Research Database (Denmark)

    Nielsen, Søren Achim; Kynde, Bjarke; Westh, Peter

    The metabolic rate was measured in the wolf spider Pardosa prativaga after preying different species of aphids, collembolans and fruit flies raised on common commercial medium. The activity of detoxification enzyme systems Glutathione S-Transferase (GST), Glutathione Peroxidase (GSTpx) was invest......The metabolic rate was measured in the wolf spider Pardosa prativaga after preying different species of aphids, collembolans and fruit flies raised on common commercial medium. The activity of detoxification enzyme systems Glutathione S-Transferase (GST), Glutathione Peroxidase (GSTpx......) was investigated for spiders preying the different species. The heat production of starved P. prativaga was ca. 1.5 mW per mg fresh weight. For specimens feed on fruit flies (Drosophila melanogaster) the heat production was appreciable higher whereas feed on the aphids Sitobion avenae and Rhopalosiphum padi...... the heat production was on the same level or lower than in the staved spiders. The variation of the observed metabolic changes was in concordance with the variations in enzyme activities....

  18. Effect of postprandial hyperglycaemia in non-invasive measurement of cerebral metabolic rate of glucose in non-diabetic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, Tatsuro; Itoh, Harumi [Department of Radiology, Fukui Medical University, Matsuoka (Japan); Sadato, Norihiro; Nishizawa, Sadahiko; Yonekura, Yoshiharu [Biomedical Imaging Research Center, Fukui Medical University (Japan)

    2002-02-01

    The aim of this study was to determine the effect of postprandial hyperglycaemia (HG) on the non-invasive measurement of cerebral metabolic rate of glucose (CMRGlc). Five patients who had a meal within an hour before a fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) examination were recruited in this study. They underwent intermittent arterial blood sampling (measured input function), and, based on this sampling, CMRGlc was calculated using an autoradiographic method (CMRGlc{sub real}). Simulated input functions were generated based on standardised input function, body surface area and net injected dose of FDG, and simulated CMRGlc (CMRGlc{sub sim}) was also calculated. Percent error of the area under the curve (AUC) between measured (AUC{sub real}) and simulated input function (AUC{sub IFsim}) and percent error between CMRGlc{sub real} and CMRGlc{sub sim} were calculated. These values were compared with those obtained from a previous study conducted under fasting conditions (F). The serum glucose level in the HG group was significantly higher than that in the F group (165{+-}69 vs 100{+-}9 mg/dl, P=0.0007). Percent errors of AUC and CMRGlc in grey matter and white matter in HG were significantly higher than those in F (12.9%{+-}1.3% vs 3.5%{+-}2.2% in AUC, P=0.0015; 18.2%{+-}2.2% vs 2.9%{+-}1.9% in CMRGlc in grey matter, P=0.0028; 24.0%{+-}4.6% vs 3.4%{+-}2.2% in CMRGlc in white matter, P=0.0028). It is concluded that a non-invasive method of measuring CMRGlc should be applied only in non-diabetic subjects under fasting conditions. (orig.)

  19. Effect of postprandial hyperglycaemia in non-invasive measurement of cerebral metabolic rate of glucose in non-diabetic subjects

    International Nuclear Information System (INIS)

    Tsuchida, Tatsuro; Itoh, Harumi; Sadato, Norihiro; Nishizawa, Sadahiko; Yonekura, Yoshiharu

    2002-01-01

    The aim of this study was to determine the effect of postprandial hyperglycaemia (HG) on the non-invasive measurement of cerebral metabolic rate of glucose (CMRGlc). Five patients who had a meal within an hour before a fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) examination were recruited in this study. They underwent intermittent arterial blood sampling (measured input function), and, based on this sampling, CMRGlc was calculated using an autoradiographic method (CMRGlc real ). Simulated input functions were generated based on standardised input function, body surface area and net injected dose of FDG, and simulated CMRGlc (CMRGlc sim ) was also calculated. Percent error of the area under the curve (AUC) between measured (AUC real ) and simulated input function (AUC IFsim ) and percent error between CMRGlc real and CMRGlc sim were calculated. These values were compared with those obtained from a previous study conducted under fasting conditions (F). The serum glucose level in the HG group was significantly higher than that in the F group (165±69 vs 100±9 mg/dl, P=0.0007). Percent errors of AUC and CMRGlc in grey matter and white matter in HG were significantly higher than those in F (12.9%±1.3% vs 3.5%±2.2% in AUC, P=0.0015; 18.2%±2.2% vs 2.9%±1.9% in CMRGlc in grey matter, P=0.0028; 24.0%±4.6% vs 3.4%±2.2% in CMRGlc in white matter, P=0.0028). It is concluded that a non-invasive method of measuring CMRGlc should be applied only in non-diabetic subjects under fasting conditions. (orig.)

  20. Metabolic rate of nocturnal incubation in female great tits, Parus major, in relation to clutch size measured in a natural environment

    NARCIS (Netherlands)

    de Heij, Maaike E.; van der Graaf, Alexandra J.; Hafner, Dennis; Tinbergen, Joost M.

    2007-01-01

    To study the energetic costs of incubation in relation to clutch size, clutch sizes were manipulated and the metabolic rate of female great tits, Parus major (Linnaeus), during nocturnal incubation (MRinc) was measured using mobile oxygen analysers. Individuals were measured on consecutive nights

  1. Does basal metabolic rate drive eating rate?

    Science.gov (United States)

    Henry, Christiani Jeyakumar; Ponnalagu, Shalini; Bi, Xinyan; Forde, Ciaran

    2018-05-15

    There have been recent advances in our understanding of the drivers of energy intake (EI). However, the biological drivers of differences in eating rate (ER) remain less clear. Studies have reported that the fat-free mass (FFM) and basal metabolic rate (BMR) are both major components that contribute to daily energy expenditure (EE) and drive EI. More recently, a number of observations report that higher ER can lead to greater EI. The current study proposed that adults with a higher BMR and higher energy requirements would also exhibit higher ERs. Data on BMR, FFM, and ER were collected from 272 Chinese adults (91 males and 181 females) in a cross-sectional study. Analysis showed significant positive associations between BMR and ER (r s  = 0.405, p BMR explained about 15% of the variation in ER which was taken to be metabolically significant. This association provides metabolic explanation that the differences in an individual's BMR (hence energy requirements) may be correlated with ERs. This merits further research. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Metabolic syndrome but not obesity measures are risk factors for accelerated age-related glomerular filtration rate decline in the general population.

    Science.gov (United States)

    Stefansson, Vidar T N; Schei, Jørgen; Solbu, Marit D; Jenssen, Trond G; Melsom, Toralf; Eriksen, Bjørn O

    2018-05-01

    Rapid age-related glomerular filtration rate (GFR) decline increases the risk of end-stage renal disease, and a low GFR increases the risk of mortality and cardiovascular disease. High body mass index and the metabolic syndrome are well-known risk factors for patients with advanced chronic kidney disease, but their role in accelerating age-related GFR decline independent of cardiovascular disease, hypertension and diabetes is not adequately understood. We studied body mass index, waist circumference, waist-hip ratio and metabolic syndrome as risk factors for accelerated GFR decline in 1261 middle-aged people representative of the general population without diabetes, cardiovascular disease or kidney disease. GFR was measured as iohexol clearance at baseline and repeated after a median of 5.6 years. Metabolic syndrome was defined as fulfilling three out of five criteria, based on waist circumference, blood pressure, glucose, high-density lipoprotein cholesterol and triglycerides. The mean GFR decline rate was 0.95 ml/min/year. Neither the body mass index, waist circumference nor waist-hip ratio predicted statistically significant changes in age-related GFR decline, but individuals with baseline metabolic syndrome had a significant mean of 0.30 ml/min/year faster decline than individuals without metabolic syndrome in a multivariable adjusted linear regression model. This association was mainly driven by the triglyceride criterion of metabolic syndrome, which was associated with a significant 0.36 ml/min/year faster decline when analyzed separately. Results differed significantly when GFR was estimated using creatinine and/or cystatin C. Thus, metabolic syndrome, but not the body mass index, waist circumference or waist-hip ratio, is an independent risk factor for accelerated age-related GFR decline in the general population. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  3. Simultaneous measurement of glucose blood–brain transport constants and metabolic rate in rat brain using in-vivo 1H MRS

    Science.gov (United States)

    Du, Fei; Zhang, Yi; Zhu, Xiao-Hong; Chen, Wei

    2012-01-01

    Cerebral glucose consumption and glucose transport across the blood–brain barrier are crucial to brain function since glucose is the major energy fuel for supporting intense electrophysiological activity associated with neuronal firing and signaling. Therefore, the development of noninvasive methods to measure the cerebral metabolic rate of glucose (CMRglc) and glucose transport constants (KT: half-saturation constant; Tmax: maximum transport rate) are of importance for understanding glucose transport mechanism and neuroenergetics under various physiological and pathological conditions. In this study, a novel approach able to simultaneously measure CMRglc, KT, and Tmax via monitoring the dynamic glucose concentration changes in the brain tissue using in-vivo 1H magnetic resonance spectroscopy (MRS) and in plasma after a brief glucose infusion was proposed and tested using an animal model. The values of CMRglc, Tmax, and KT were determined to be 0.44±0.17 μmol/g per minute, 1.35±0.47 μmol/g per minute, and 13.4±6.8 mmol/L in the rat brain anesthetized with 2% isoflurane. The Monte-Carlo simulations suggest that the measurements of CMRglc and Tmax are more reliable than that of KT. The overall results indicate that the new approach is robust and reliable for in-vivo measurements of both brain glucose metabolic rate and transport constants, and has potential for human application. PMID:22714049

  4. Metabolic, respiratory, and cardiological measurements during exercise and rest

    Science.gov (United States)

    1971-01-01

    Low concentration effects of CO2 on metabolic respiration and circulation were measured during work and at rest. The relationship between heart rate and metabolic rate is examined, as well as calibration procedures, and rate measurement during submaximal and standard exercise tests. Alterations in acid base and electrolytes were found during exhaustive exercise, including changes in ECG and metabolic alkalosis effects.

  5. Metabolic rates of giant pandas inform conservation strategies

    Science.gov (United States)

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

    2016-01-01

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction. PMID:27264109

  6. Metabolic rates of giant pandas inform conservation strategies

    Science.gov (United States)

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

    2016-06-01

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

  7. 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. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

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

    OpenAIRE

    de Figueiredo Ferreira, Marina; Detrano, Filipe; Coelho, Gabriela Morgado de Oliveira; Barros, Maria Elisa; Serrão Lanzillotti, Regina; Firmino Nogueira Neto, José; Portella, Emilson Souza; Serrão Lanzillotti, Haydée; Soares, Eliane de Abreu

    2014-01-01

    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 als...

  9. Comparative evaluation of SUV, tumor-to-blood standard uptake ratio (SUR), and dual time point measurements for assessment of the metabolic uptake rate in FDG PET.

    Science.gov (United States)

    Hofheinz, Frank; Hoff, Jörg van den; Steffen, Ingo G; Lougovski, Alexandr; Ego, Kilian; Amthauer, Holger; Apostolova, Ivayla

    2016-12-01

    We have demonstrated recently that the tumor-to-blood standard uptake ratio (SUR) is superior to tumor standardized uptake value (SUV) as a surrogate of the metabolic uptake rate K m of fluorodeoxyglucose (FDG), overcoming several of the known shortcomings of the SUV approach: excellent linear correlation of SUR and K m from Patlak analysis was found using dynamic imaging of liver metastases. However, due to the perfectly standardized uptake period used for SUR determination and the comparatively short uptake period, these results are not automatically valid and applicable for clinical whole-body examinations in which the uptake periods (T) are distinctly longer and can vary considerably. Therefore, the aim of this work was to investigate the correlation between SUR derived from clinical static whole-body scans and K m-surrogate derived from dual time point (DTP) measurements. DTP (18)F-FDG PET/CT was performed in 90 consecutive patients with histologically proven non-small cell lung cancer (NSCLC). In the PET images, the primary tumor was delineated with an adaptive threshold method. For determination of the blood SUV, an aorta region of interest (ROI) was delineated manually in the attenuation CT and transferred to the PET image. Blood SUV was computed as the mean value of the aorta ROI. SUR values were computed as ratio of tumor SUV and blood SUV. SUR values from the early time point of each DTP measurement were scan time corrected to 75 min postinjection (SURtc). As surrogate of K m, we used the SUR(T) slope, K slope, derived from DTP measurements since it is proportional to the latter under the given circumstances. The correlation of SUV and SURtc with K slope was investigated. The prognostic value of SUV, SURtc, and K slope for overall survival (OS) and progression-free survival (PFS) was investigated with univariate Cox regression in a homogeneous subgroup (N=31) treated with primary chemoradiation. Correlation analysis revealed for both, SUV and SURtc, a

  10. 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 ...

  11. Fluctuating selection on basal metabolic rate.

    Science.gov (United States)

    Nilsson, Johan F; Nilsson, Jan-Åke

    2016-02-01

    BMR (Basal metabolic rate) is an important trait in animal life history as it represents a significant part of animal energy budgets. BMR has also been shown to be positively related to sustainable work rate and maximal thermoregulatory capacity. To this date, most of the studies have focused on the causes of interspecific and intraspecific variation in BMR, and fairly little is known about the fitness consequences of different metabolic strategies. In this study, we show that winter BMR affects local survival in a population of wild blue tits (Cyanistes caeruleus), but that the selection direction differs between years. We argue that this fluctuating selection is probably a consequence of varying winter climate with a positive relation between survival and BMR during cold and harsh conditions, but a negative relation during mild winters. This fluctuating selection can not only explain the pronounced variation in BMR in wild populations, but will also give us new insights into how energy turnover rates can shape the life-history strategies of animals. Furthermore, the study shows that the process of global warming may cause directional selection for a general reduction in BMR, affecting the general life-history strategy on the population level.

  12. 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.

  13. 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

  14. 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

  15. Determinants of inter-specific variation in basal metabolic rate.

    Science.gov (United States)

    White, Craig R; Kearney, Michael R

    2013-01-01

    Basal metabolic rate (BMR) is the rate of metabolism of a resting, postabsorptive, non-reproductive, adult bird or mammal, measured during the inactive circadian phase at a thermoneutral temperature. BMR is one of the most widely measured physiological traits, and data are available for over 1,200 species. With data available for such a wide range of species, BMR is a benchmark measurement in ecological and evolutionary physiology, and is often used as a reference against which other levels of metabolism are compared. Implicit in such comparisons is the assumption that BMR is invariant for a given species and that it therefore represents a stable point of comparison. However, BMR shows substantial variation between individuals, populations and species. Investigation of the ultimate (evolutionary) explanations for these differences remains an active area of inquiry, and explanation of size-related trends remains a contentious area. Whereas explanations for the scaling of BMR are generally mechanistic and claim ties to the first principles of chemistry and physics, investigations of mass-independent variation typically take an evolutionary perspective and have demonstrated that BMR is ultimately linked with a range of extrinsic variables including diet, habitat temperature, and net primary productivity. Here we review explanations for size-related and mass-independent variation in the BMR of animals, and suggest ways that the various explanations can be evaluated and integrated.

  16. 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 im...

  17. Cellular metabolic rates from primary dermal fibroblast cells isolated from birds of different body masses.

    Science.gov (United States)

    Jimenez, Ana Gabriela; Williams, Joseph B

    2014-10-01

    The rate of metabolism is the speed at which organisms use energy, an integration of energy transformations within the body; it governs biological processes that influence rates of growth and reproduction. Progress at understanding functional linkages between whole organism metabolic rate and underlying mechanisms that influence its magnitude has been slow despite the central role this issue plays in evolutionary and physiological ecology. Previous studies that have attempted to relate how cellular processes translate into whole-organism physiology have done so over a range of body masses of subjects. However, the data still remains controversial when observing metabolic rates at the cellular level. To bridge the gap between these ideas, we examined cellular metabolic rate of primary dermal fibroblasts isolated from 49 species of birds representing a 32,000-fold range in body masses to test the hypothesis that metabolic rate of cultured cells scales with body size. We used a Seahorse XF-96 Extracellular flux analyzer to measure cellular respiration in fibroblasts. Additionally, we measured fibroblast size and mitochondrial content. We found no significant correlation between cellular metabolic rate, cell size, or mitochondrial content and body mass. Additionally, there was a significant relationship between cellular basal metabolic rate and proton leak in these cells. We conclude that metabolic rate of cells isolated in culture does not scale with body mass, but cellular metabolic rate is correlated to growth rate in birds. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. 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...

  19. Basal metabolic rate and risk-taking behaviour in birds.

    Science.gov (United States)

    Møller, A P

    2009-12-01

    Basal metabolic rate (BMR) constitutes the minimal metabolic rate in the zone of thermo-neutrality, where heat production is not elevated for temperature regulation. BMR thus constitutes the minimum metabolic rate that is required for maintenance. Interspecific variation in BMR in birds is correlated with food habits, climate, habitat, flight activity, torpor, altitude, and migration, although the selective forces involved in the evolution of these presumed adaptations are not always obvious. I suggest that BMR constitutes the minimum level required for maintenance, and that variation in this minimum level reflects the fitness costs and benefits in terms of ability to respond to selective agents like predators, implying that an elevated level of BMR is a cost of wariness towards predators. This hypothesis predicts a positive relationship between BMR and measures of risk taking such as flight initiation distance (FID) of individuals approached by a potential predator. Consistent with this suggestion, I show in a comparative analysis of 76 bird species that species with higher BMR for their body mass have longer FID when approached by a potential predator. This effect was independent of potentially confounding variables and similarity among species due to common phylogenetic descent. These results imply that BMR is positively related to risk-taking behaviour, and that predation constitutes a neglected factor in the evolution of BMR.

  20. Measurement of regional cerebral metabolic rate for glucose in the human subject with (F-18)-2-deoxy-2-fluoro-d-glucose and emission computed tomography: validation of the method

    International Nuclear Information System (INIS)

    Phelps, M.E.; Huang, S.C.; Hoffman, E.J.; Selin, C.; Kuhl, D.E.

    1977-01-01

    Tracer techniques and models of in vitro quantitative autoradiography and tissue counting for the measure of regional metabolic rates (rMR) are combined with emission computed tomography (ECT). This approach, Physiologic Tomography (PT), provides atraumatic and analytical measurements of rMR. PT is exemplified with the regional measurement of the cerebral metabolic rate for glucose (CMRGlu) in man with ( 18 F)-2-deoxy-2-fluoro-D-glucose (FDG) and positron ECT. Our model incorporates a k 4 * mediated hydrolysis of FDG-6-PO 4 to FDG which then competes with phosphorylation (k 3 *) of FDG back to FDG-6-PO 4 and reverse transport (k 2 *) back to blood. Although small, k 4 * is found to be significant. The ECAT positron tomograph was used to measure the rate constants (k 1 *→k 4 *), lumped constant (LC), stability, and reproducibility of the model in man. Since these parameters have not been measured for FDG in any species, comparisons are made to values for DG in rat and monkey. Compartmental concentrations of FDG and FDG-6-PO 4 were determined and show that cerebral FDG-6-PO 4 steadily accumulates for about 100 mins, plateaus and then slowly decreases due to hydrolysis. Cerebral blood FDG concentration was determined to be a minor contribution to tissue activity after 10 min. Regional CMRGlu measurements are reproducible to +- 5.5% over 5 hrs. PT allows the in vivo study ofregional biochemistry and physiology in normal and pathophysiologic states in man with a unique and fundamental capability

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

    African Journals Online (AJOL)

    The method used in measuring the metabolic rate was by indirect calorimetry. Results showed that the different food- carbohydrate, protein and fat ingestion each, caused a significant increase (p<0.0001) when compared with the control metabolic rate. Comparing the effect of the three, protein ingestion caused the greatest ...

  2. Is the rate of metabolic ageing and survival determined by Basal metabolic rate in the zebra finch?

    Directory of Open Access Journals (Sweden)

    Bernt Rønning

    Full Text Available The relationship between energy metabolism and ageing is of great interest because aerobic metabolism is the primary source of reactive oxygen species which is believed to be of major importance in the ageing process. We conducted a longitudinal study on captive zebra finches where we tested the effect of age on basal metabolic rate (BMR, as well as the effect of BMR on the rate of metabolic ageing (decline in BMR with age and survival. Basal metabolic rate declined with age in both sexes after controlling for the effect of body mass, indicating a loss of functionality with age. This loss of functionality could be due to accumulated oxidative damage, believed to increase with increasing metabolic rate, c.f. the free radical theory of ageing. If so, we would expect the rate of metabolic ageing to increase and survival to decrease with increasing BMR. However, we found no effect of BMR on the rate of metabolic ageing. Furthermore, survival was not affected by BMR in the males. In female zebra finches there was a tendency for survival to decrease with increasing BMR, but the effect did not reach significance (P<0.1. Thus, the effect of BMR on the rate of functional deterioration with age, if any, was not strong enough to influence neither the rate of metabolic ageing nor survival in the zebra finches.

  3. Is the rate of metabolic ageing and survival determined by Basal metabolic rate in the zebra finch?

    Science.gov (United States)

    Rønning, Bernt; Moe, Børge; Berntsen, Henrik H; Noreen, Elin; Bech, Claus

    2014-01-01

    The relationship between energy metabolism and ageing is of great interest because aerobic metabolism is the primary source of reactive oxygen species which is believed to be of major importance in the ageing process. We conducted a longitudinal study on captive zebra finches where we tested the effect of age on basal metabolic rate (BMR), as well as the effect of BMR on the rate of metabolic ageing (decline in BMR with age) and survival. Basal metabolic rate declined with age in both sexes after controlling for the effect of body mass, indicating a loss of functionality with age. This loss of functionality could be due to accumulated oxidative damage, believed to increase with increasing metabolic rate, c.f. the free radical theory of ageing. If so, we would expect the rate of metabolic ageing to increase and survival to decrease with increasing BMR. However, we found no effect of BMR on the rate of metabolic ageing. Furthermore, survival was not affected by BMR in the males. In female zebra finches there was a tendency for survival to decrease with increasing BMR, but the effect did not reach significance (PBMR on the rate of functional deterioration with age, if any, was not strong enough to influence neither the rate of metabolic ageing nor survival in the zebra finches.

  4. 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.

  5. 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

    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...

  6. 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...

  7. Resting metabolic rate and postprandial thermogenesis in polycystic ovarian syndrome.

    Science.gov (United States)

    Segal, K R; Dunaif, A

    1990-07-01

    To determine whether the high frequency of obesity in women with polycystic ovary syndrome (PCO) is related to a defect in energy expenditure, resting metabolic rate (RMR) and the thermic response to a standard meal were compared in 10 obese PCO women, nine obese but otherwise normal women, and 11 lean women. All groups were matched with respect to age and fat-free mass and the two obese groups were matched for degree of obesity. RMR was measured by indirect calorimetry for 3 h on two days: (1) in the postabsorptive state; and (2) after a 720 kcal (3014 kJ) liquid mixed meal. The thermic effect of food, calculated as 3 h postprandial minus fasting RMR, was significantly greater for the lean [52.9 +/- 5.5 kcal/3 h (221 +/- 23 kJ/3 h)] than the obese [17.2 +/- 5.1 kcal/3 h (72 +/- 21 kJ/3 h)] and the PCO women [22.8 +/- 5.2 kcal/3 h (95 +/- 22 kJ/3)], P less than 0.001). The thermic effect of food was negatively related to percent body fat (r = -0.694, P less than 0.001). Resting metabolic rate did not differ significantly among the three groups, and was strongly related to fat-free mass (r = 0.687, P less than 0.001). These results confirm previous reports of blunted thermogenesis in obese individuals, but provide no evidence of altered resting metabolic rate or postprandial thermogenesis in women with PCO compared with normal women of similar degree of obesity.

  8. Palaeohistological Evidence for Ancestral High Metabolic Rate in Archosaurs.

    Science.gov (United States)

    Legendre, Lucas J; Guénard, Guillaume; Botha-Brink, Jennifer; Cubo, Jorge

    2016-11-01

    Metabolic heat production in archosaurs has played an important role in their evolutionary radiation during the Mesozoic, and their ancestral metabolic condition has long been a matter of debate in systematics and palaeontology. The study of fossil bone histology provides crucial information on bone growth rate, which has been used to indirectly investigate the evolution of thermometabolism in archosaurs. However, no quantitative estimation of metabolic rate has ever been performed on fossils using bone histological features. Moreover, to date, no inference model has included phylogenetic information in the form of predictive variables. Here we performed statistical predictive modeling using the new method of phylogenetic eigenvector maps on a set of bone histological features for a sample of extant and extinct vertebrates, to estimate metabolic rates of fossil archosauromorphs. This modeling procedure serves as a case study for eigenvector-based predictive modeling in a phylogenetic context, as well as an investigation of the poorly known evolutionary patterns of metabolic rate in archosaurs. Our results show that Mesozoic theropod dinosaurs exhibit metabolic rates very close to those found in modern birds, that archosaurs share a higher ancestral metabolic rate than that of extant ectotherms, and that this derived high metabolic rate was acquired at a much more inclusive level of the phylogenetic tree, among non-archosaurian archosauromorphs. These results also highlight the difficulties of assigning a given heat production strategy (i.e., endothermy, ectothermy) to an estimated metabolic rate value, and confirm findings of previous studies that the definition of the endotherm/ectotherm dichotomy may be ambiguous. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. 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.

  10. Computerized system for measuring cerebral metabolism

    International Nuclear Information System (INIS)

    McGlone, J.S.; Hibbard, L.S.; Hawkins, R.A.; Kasturi, R.

    1987-01-01

    A computerized stereotactic measurement system for evaluating rat brain metabolism was developed to utilize the large amount of data generated by quantitative autoradiography. Conventional methods of measurement only analyze a small percent of these data because these methods are limited by instrument design and the subjectiveness of the investigator. However, a computerized system allows digital images to be analyzed by placing data at their appropriate three-dimensional stereotactic coordinates. The system automatically registers experimental data to a standard three-dimensional image using alignment, scaling, and matching operations. Metabolic activity in different neuronal structures is then measured by generating digital masks and superimposing them on to experimental data. Several experimental data sets were evaluated and it was noticed that the structures measured by the computerized system, had in general, lower metabolic activity than manual measurements had indicated. This was expected because the computerized system measured the structure over its volume while the manual readings were taken from the most active metabolic area of a particular structure

  11. Metabolic rate and body temperature of an African sun bird ...

    African Journals Online (AJOL)

    1997-02-19

    Feb 19, 1997 ... has a wide distribution in southern Africa. ... sample the voltage output of the oxygen analyser every 2 min ... Bailey Bat thermocouple thermometer, and the system was .... A similar 50% drop in metabolic rate in finches at.

  12. Metabolic rate determines haematopoietic stem cell self-renewal.

    Science.gov (United States)

    Sastry, P S R K

    2004-01-01

    The number of haematopoietic stem cells (HSCs) per animal is conserved across species. This means the HSCs need to maintain hematopoiesis over a longer period in larger animals. This would result in the requirement of stem cell self-renewal. At present the three existing models are the stochastic model, instructive model and the third more recently proposed is the chiaro-scuro model. It is a well known allometric law that metabolic rate scales to the three quarter power. Larger animals have a lower metabolic rate, compared to smaller animals. Here it is being hypothesized that metabolic rate determines haematopoietic stem cell self-renewal. At lower metabolic rate the stem cells commit for self-renewal, where as at higher metabolic rate they become committed to different lineages. The present hypothesis can explain the salient features of the different models. Recent findings regarding stem cell self-renewal suggest an important role for Wnt proteins and their receptors known as frizzleds, which are an important component of cell signaling pathway. The role of cGMP in the Wnts action provides further justification for the present hypothesis as cGMP is intricately linked to metabolic rate. One can also explain the telomere homeostasis by the present hypothesis. One prediction of the present hypothesis is with reference to the limit of cell divisions known as Hayflick limit, here it is being suggested that this is the result of metabolic rate in laboratory conditions and there can be higher number of cell divisions in vivo if the metabolic rate is lower. Copyright 2004 Elsevier Ltd.

  13. Metabolic rate and thermal conductance of lemmings from high-arctic Canada and Siberia

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Agrell, J.; Lindström, A.

    2002-01-01

    The arctic climate places high demands on the energy metabolism of its inhabitants. We measured resting (RMR) and basal metabolic rates (BMR), body temperatures, and dry and wet thermal conductances in summer morphs of the lemmings Dicrostonyx groenlandicus and Lemmus trimucronatus in arctic Canada,

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

    African Journals Online (AJOL)

    Exercise-induced maximum metabolic rate scaled to body mass by the fractal ... rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is ... muscle stress limitation, and maximized oxygen delivery and metabolic rates.

  15. Predicting basal metabolic rates in Malaysian adult elite athletes.

    Science.gov (United States)

    Wong, Jyh Eiin; Poh, Bee Koon; Nik Shanita, Safii; Izham, Mohd Mohamad; Chan, Kai Quin; Tai, Meng De; Ng, Wei Wei; Ismail, Mohd Noor

    2012-11-01

    This study aimed to measure the basal metabolic rate (BMR) of elite athletes and develop a gender specific predictive equation to estimate their energy requirements. 92 men and 33 women (aged 18-31 years) from 15 sports, who had been training six hours daily for at least one year, were included in the study. Body composition was measured using the bioimpedance technique, and BMR by indirect calorimetry. The differences between measured and estimated BMR using various predictive equations were calculated. The novel equation derived from stepwise multiple regression was evaluated using Bland and Altman analysis. The predictive equations of Cunningham and the Food and Agriculture Organization/World Health Organization/United Nations University either over- or underestimated the measured BMR by up to ± 6%, while the equations of Ismail et al, developed from the local non-athletic population, underestimated the measured BMR by 14%. The novel predictive equation for the BMR of athletes was BMR (kcal/day) = 669 + 13 (weight in kg) + 192 (gender: 1 for men and 0 for women) (R2 0.548; standard error of estimates 163 kcal). Predicted BMRs of elite athletes by this equation were within 1.2% ± 9.5% of the measured BMR values. The novel predictive equation presented in this study can be used to calculate BMR for adult Malaysian elite athletes. Further studies may be required to validate its predictive capabilities for other sports, nationalities and age groups.

  16. 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.

  17. 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

  18. True mean rate measuring system

    International Nuclear Information System (INIS)

    Eichenlaub, D.P.

    1980-01-01

    A digital radiation-monitoring system for nuclear power plants uses digital and microprocessor circuitry to enable rapid processing of pulse information from remote radiation monitors. The pulse rates are analyzed to determine whether new pulse-rate information is statisticaly the same as that previously received and to determine the best possible averaging time, which can be changed so that the statistical error remains below a specified level while the system response time remains short. Several data modules each process the pulse-rate information from several remote radiation monitors. Each data module accepts pulse data from each radiation monitor and measures the true average or mean pulse rate of events occurring with a Poisson distribution to determine the radiation level. They then develop digital output signals which indciate the respective radiation levels and which can be transmitted via multiplexer circuits for additional processing and display. The data modules can accept signals from remote control stations or computer stations via the multiplexer circuit to change operating thresholds and alarm levels in their memories. A check module scans the various data modules to determine whether the output signals are valid. It also acts as a redundant data module and will automatically replace an inoperative unit. (DN)

  19. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    International Nuclear Information System (INIS)

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G.

    1990-01-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states

  20. 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...... composition (e.g. abdominal fat) may be more so. Basal metabolic rate (BMR) is an expression of resting metabolism and may serve as a complementary tool when assessing the possibly underlying metabolism behind a persons' body composition. OBJECTIVE: To investigate the body composition and basal metabolic rate...... in individuals with HS compared with healthy controls. METHODS: We performed a cross-sectional study on both a hospital-based and population-based HS group and compared with controls using Bioelectrical Impedance Analysis to assess body composition. RESULTS: We identified a hospital-based HS group of 32 hospital...

  1. PET measurements of cerebral metabolism corrected for CSF contributions

    International Nuclear Information System (INIS)

    Chawluk, J.; Alavi, A.; Dann, R.; Kushner, M.J.; Hurtig, H.; Zimmerman, R.A.; Reivich, M.

    1984-01-01

    Thirty-three subjects have been studied with PET and anatomic imaging (proton-NMR and/or CT) in order to determine the effect of cerebral atrophy on calculations of metabolic rates. Subgroups of neurologic disease investigated include stroke, brain tumor, epilepsy, psychosis, and dementia. Anatomic images were digitized through a Vidicon camera and analyzed volumetrically. Relative areas for ventricles, sulci, and brain tissue were calculated. Preliminary analysis suggests that ventricular volumes as determined by NMR and CT are similar, while sulcal volumes are larger on NMR scans. Metabolic rates (18F-FDG) were calculated before and after correction for CSF spaces, with initial focus upon dementia and normal aging. Correction for atrophy led to a greater increase (%) in global metabolic rates in demented individuals (18.2 +- 5.3) compared to elderly controls (8.3 +- 3.0,p < .05). A trend towards significantly lower glucose metabolism in demented subjects before CSF correction was not seen following correction for atrophy. These data suggest that volumetric analysis of NMR images may more accurately reflect the degree of cerebral atrophy, since NMR does not suffer from beam hardening artifact due to bone-parenchyma juxtapositions. Furthermore, appropriate correction for CSF spaces should be employed if current resolution PET scanners are to accurately measure residual brain tissue metabolism in various pathological states

  2. Radiation dose rate measuring device

    International Nuclear Information System (INIS)

    Sorber, R.

    1987-01-01

    A portable device is described for in-field usage for measuring the dose rate of an ambient beta radiation field, comprising: a housing, substantially impervious to beta radiation, defining an ionization chamber and having an opening into the ionization chamber; beta radiation pervious electrically-conductive window means covering the opening and entrapping, within the ionization chamber, a quantity of gaseous molecules adapted to ionize upon impact with beta radiation particles; electrode means disposed within the ionization chamber and having a generally shallow concave surface terminating in a generally annular rim disposed at a substantially close spacing to the window means. It is configured to substantially conform to the window means to define a known beta radiation sensitive volume generally between the window means and the concave surface of the electrode means. The concave surface is effective to substantially fully expose the beta radiation sensitive volume to the radiation field over substantially the full ambient area faced by the window means

  3. 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.

  4. 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.

  5. Long-term effect of yogic practices on diurnal metabolic rates of healthy subjects

    Directory of Open Access Journals (Sweden)

    Chaya M

    2008-01-01

    Full Text Available Background: The metabolic rate is an indicator of autonomic activity. Reduced sympathetic arousal probably resulting in hypometabolic states has been reported in several yogic studies. Aim: The main objective of this study was to assess the effect of yoga training on diurnal metabolic rates in yoga practitioners at two different times of the day (at 6 a.m. and 9 p.m.. Methods and Material: Eighty eight healthy volunteers were selected and their metabolic rates assessed at 6 a.m. and 9 p.m. using an indirect calorimeter at a yoga school in Bangalore, India. Results and conclusions: The results show that the average metabolic rate of the yoga group was 12% lower than that of the non-yoga group ( P < 0.001 measured at 9 p.m. and 16% lower at 6 a.m. ( P < 0.001. The 9 p.m. metabolic rates of the yoga group were almost equal to their predicted basal metabolic rates (BMRs whereas the metabolic rate was significantly higher than the predicted BMR for the non-yoga group. The 6 a.m. metabolic rate was comparable to their predicted BMR in the non-yoga group whereas it was much lower in the yoga group ( P < 0.001. The lower metabolic rates in the yoga group at 6 a.m. and 9 p.m. may be due to coping strategies for day-to-day stress, decreased sympathetic nervous system activity and probably, a stable autonomic nervous system response (to different stressors achieved due to training in yoga.

  6. Long-term effect of yogic practices on diurnal metabolic rates of healthy subjects

    Directory of Open Access Journals (Sweden)

    Chaya M

    2008-01-01

    Full Text Available Background : The metabolic rate is an indicator of autonomic activity. Reduced sympathetic arousal probably resulting in hypometabolic states has been reported in several yogic studies. Aim : The main objective of this study was to assess the effect of yoga training on diurnal metabolic rates in yoga practitioners at two different times of the day (at 6 a.m. and 9 p.m.. Materials and Methods : Eighty eight healthy volunteers were selected and their metabolic rates assessed at 6 a.m. and 9 p.m. using an indirect calorimeter at a yoga school in Bangalore, India. Results and conclusions: The results show that the average metabolic rate of the yoga group was 12% lower than that of the non-yoga group ( P < 0.001 measured at 9 p.m. and 16% lower at 6 a.m. ( P < 0.001. The 9 p.m. metabolic rates of the yoga group were almost equal to their predicted basal metabolic rates (BMRs whereas the metabolic rate was significantly higher than the predicted BMR for the non-yoga group. The 6 a.m. metabolic rate was comparable to their predicted BMR in the non-yoga group whereas it was much lower in the yoga group ( P < 0.001. The lower metabolic rates in the yoga group at 6 a.m. and 9 p.m. may be due to coping strategies for day-to-day stress, decreased sympathetic nervous system activity and probably, a stable autonomic nervous system response (to different stressors achieved due to training in yoga.

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

    International Nuclear Information System (INIS)

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr.; Gillin, J.C.

    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

  8. 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,

  9. 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.

  10. Measuring Glial Metabolism in Repetitive Brain Trauma and Alzheimers Disease

    Science.gov (United States)

    2017-09-01

    4: Correlate the glial and glutamate metabolic rates with additional measures obtained in the parent studies including of a) serum, CSF, and genetic...resonances as a linear combination model. Note the high SNR of glutamate and its separation from other metabolites that would overlap at 3 Tesla. 3.3... separate protocol offered to participants in the study but will not be mandatory and thus will not impact this study in any way. 3.4. Results

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

    Science.gov (United States)

    Wone, B W M; Madsen, P; Donovan, E R; Labocha, M K; Sears, M W; Downs, C J; Sorensen, D A; Hayes, J P

    2015-04-01

    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, and BMR was slightly, but not significantly, higher (2.5%). Compared with controls, MMR was significantly higher (5.3%) in antagonistically selected lines, and BMR was slightly, but not significantly, lower (4.2%). Analysis of breeding values revealed no positive genetic trend for elevated BMR in high-MMR lines. A weak positive genetic correlation was detected between MMR and BMR. That weak positive genetic correlation supports the aerobic capacity model for the evolution of endothermy in the sense that it fails to falsify a key model assumption. Overall, the results suggest that at least in these mice there is significant capacity for independent evolution of metabolic traits. Whether that is true in the ancestral animals that evolved endothermy remains an important but unanswered question.

  12. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    OpenAIRE

    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...

  13. Covariation of metabolic rates and cell size in coccolithophores

    Science.gov (United States)

    Aloisi, G.

    2015-08-01

    Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size). I show that growth, photosynthesis and, to a lesser extent, calcification covary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature (below the optimum temperature for growth) produces the opposite effect. The magnitude of the coccosphere-size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment-metabolism-size link are understood, it will be possible to use coccosphere-size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. The coccolithophore database is strongly biased in favour of experiments with the coccolithophore Emiliania huxleyi (E. huxleyi; 82 % of database entries), and more experiments with other species are needed to understand whether these observations can be extended to coccolithophores in general. I

  14. 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.

  15. 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

  16. The relationship between body mass and field metabolic rate among individual birds and mammals.

    Science.gov (United States)

    Hudson, Lawrence N; Isaac, Nick J B; Reuman, Daniel C

    2013-09-01

    1. The power-law dependence of metabolic rate on body mass has major implications at every level of ecological organization. However, the overwhelming majority of studies examining this relationship have used basal or resting metabolic rates, and/or have used data consisting of species-averaged masses and metabolic rates. Field metabolic rates are more ecologically relevant and are probably more directly subject to natural selection than basal rates. Individual rates might be more important than species-average rates in determining the outcome of ecological interactions, and hence selection. 2. We here provide the first comprehensive database of published field metabolic rates and body masses of individual birds and mammals, containing measurements of 1498 animals of 133 species in 28 orders. We used linear mixed-effects models to answer questions about the body mass scaling of metabolic rate and its taxonomic universality/heterogeneity that have become classic areas of controversy. Our statistical approach allows mean scaling exponents and taxonomic heterogeneity in scaling to be analysed in a unified way while simultaneously accounting for nonindependence in the data due to shared evolutionary history of related species. 3. The mean power-law scaling exponents of metabolic rate vs. body mass relationships were 0.71 [95% confidence intervals (CI) 0.625-0.795] for birds and 0.64 (95% CI 0.564-0.716) for mammals. However, these central tendencies obscured meaningful taxonomic heterogeneity in scaling exponents. The primary taxonomic level at which heterogeneity occurred was the order level. Substantial heterogeneity also occurred at the species level, a fact that cannot be revealed by species-averaged data sets used in prior work. Variability in scaling exponents at both order and species levels was comparable to or exceeded the differences 3/4-2/3 = 1/12 and 0.71-0.64. 4. Results are interpreted in the light of a variety of existing theories. In particular, results

  17. 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.

  18. 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

  19. Helicoverpa armigera (Lepidoptera: Noctuidae) larvae that survive sublethal doses of nucleopolyhedrovirus exhibit high metabolic rates.

    Science.gov (United States)

    Bouwer, Gustav; Nardini, Luisa; Duncan, Frances D

    2009-04-01

    To determine the effect of sublethal doses of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearSNPV) on the metabolic rate of H. armigera, the respiration rates of third instar H. armigera larvae inoculated with sublethal doses of HearSNPV were evaluated. Respiration rates, measured as the rate of CO(2) production (VCO(2)), were recorded daily using closed-system respirometry. By 4 days post-inoculation (dpi), the metabolic rates of LD(25) or LD(75) survivors were significantly higher than that of uninoculated controls. When dose data were pooled, the VCO(2) values of larvae that survived inoculation (0.0288mlh(-1)), the uninoculated controls (0.0250mlh(-1)), and the larvae that did not survive inoculation (0.0199mlh(-1)) differed significantly from one another. At 4dpi, the VCO(2) of the uninoculated controls were significantly lower than the VCO(2) of inoculation survivors, but significantly higher than the VCO(2) of inoculation non-survivors. Inoculation survivors may have had high metabolic rates due to a combination of viral replication, organ damage, and an energy-intensive induced cellular immune response. The high 4dpi metabolic rate of inoculation survivors may reflect an effective immune response and may be seen as the metabolic signature of larvae that are in the process of surviving inoculation with HearSNPV.

  20. Metabolic clearance and blood production rates of estradiol in hyperthyroidism.

    Science.gov (United States)

    Ridgway, E C; Longcope, C; Maloof, F

    1975-09-01

    The metabolic clearance rate of 17beta-estradiol (MCR2), the plasma levels of 17beta-estradiol (E2)1, sex-steroid binding globulin (SSBG), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured in 10 hyperthyroid subjects (7 men and 3 women). The blood production rate of 17beta-estradiol (PB2) was calculated for all subjects. Nine of the 10 hyperthyroid subjects had a decreased MCR2 which returned towards normal in 5 of the 6 subjects restudied following therapy. In all 10 subjects the levels of SSBG were increased when they were hyperthyroid and returned toward normal with therapy. It is concluded that the decrease in MCR2 is largely due to the increased binding of 17beta-estradiol to SSBG. In 7 of the 10 hyperthyroid the plasma E2 concentrations were normal whereas 3 had slightly elevated levels. In 8 of the 10 hyperthyroid the PB2 was within the normal range. Only 2 hyperthyroid subjects had slightly elevated PB2. In the 6 subjects who were restudied after therapy, there was no consistent change in PB2 which remained in the normal range in all cases. It is concluded that the MCR2 is decreased in most subjects with hyperthyroidism in association with an increase of SSBG. Despite this change in MCR2 there is no significant change in PB2. The increase in SSBG levels in hyperthyroidism appears to be a direct effect of the elevation of thyroid hormone activity and is not mediated through estrogen.

  1. 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

  2. Increased metabolic turnover rate and transcapillary escape rate of albumin in long-term juvenile diabetics

    DEFF Research Database (Denmark)

    Parving, H H; Rossing, N; Sander, E

    1975-01-01

    The metabolic turnover rate and transcapillary escape rate of albumin were studied with 131I-labelled human albumin in nine patients with long-term diabetes mellitus. Retinopathy was present in all patients and nephropathy in four. Plasma albumin concentration and plasma volume were reduced (P...

  3. 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.

  4. 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.

  5. 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

  6. [Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

    Science.gov (United States)

    Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

    2003-01-01

    Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

  7. Behavioral and physiological significance of minimum resting metabolic rate in king penguins.

    Science.gov (United States)

    Halsey, L G; Butler, P J; Fahlman, A; Woakes, A J; Handrich, Y

    2008-01-01

    Because fasting king penguins (Aptenodytes patagonicus) need to conserve energy, it is possible that they exhibit particularly low metabolic rates during periods of rest. We investigated the behavioral and physiological aspects of periods of minimum metabolic rate in king penguins under different circumstances. Heart rate (f(H)) measurements were recorded to estimate rate of oxygen consumption during periods of rest. Furthermore, apparent respiratory sinus arrhythmia (RSA) was calculated from the f(H) data to determine probable breathing frequency in resting penguins. The most pertinent results were that minimum f(H) achieved (over 5 min) was higher during respirometry experiments in air than during periods ashore in the field; that minimum f(H) during respirometry experiments on water was similar to that while at sea; and that RSA was apparent in many of the f(H) traces during periods of minimum f(H) and provides accurate estimates of breathing rates of king penguins resting in specific situations in the field. Inferences made from the results include that king penguins do not have the capacity to reduce their metabolism to a particularly low level on land; that they can, however, achieve surprisingly low metabolic rates at sea while resting in cold water; and that during respirometry experiments king penguins are stressed to some degree, exhibiting an elevated metabolism even when resting.

  8. 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

    , 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...... 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....

  9. Correlations of metabolic rate and body acceleration in three species of coastal sharks under contrasting temperature regimes.

    Science.gov (United States)

    Lear, Karissa O; Whitney, Nicholas M; Brewster, Lauran R; Morris, Jack J; Hueter, Robert E; Gleiss, Adrian C

    2017-02-01

    The ability to produce estimates of the metabolic rate of free-ranging animals is fundamental to the study of their ecology. However, measuring the energy expenditure of animals in the field has proved difficult, especially for aquatic taxa. Accelerometry presents a means of translating metabolic rates measured in the laboratory to individuals studied in the field, pending appropriate laboratory calibrations. Such calibrations have only been performed on a few fish species to date, and only one where the effects of temperature were accounted for. Here, we present calibrations between activity, measured as overall dynamic body acceleration (ODBA), and metabolic rate, measured through respirometry, for nurse sharks (Ginglymostoma cirratum), lemon sharks (Negaprion brevirostris) and blacktip sharks (Carcharhinus limbatus). Calibrations were made at a range of volitional swimming speeds and experimental temperatures. Linear mixed models were used to determine a predictive equation for metabolic rate based on measured ODBA values, with the optimal model using ODBA in combination with activity state and temperature to predict metabolic rate in lemon and nurse sharks, and ODBA and temperature to predict metabolic rate in blacktip sharks. This study lays the groundwork for calculating the metabolic rate of these species in the wild using acceleration data. © 2017. Published by The Company of Biologists Ltd.

  10. Reduced basal metabolic rate of migratory waders wintering in coastal Africa

    NARCIS (Netherlands)

    Kersten, M.; Bruinzeel, L.W.; Wiersma, P.; Piersma, T.

    1998-01-01

    We measured Basal Metabolic Rate (EMR) of 16 wader species (order Charadriiformes) on their wintering grounds in Africa. The allometric regression equation relating BMR to body mass: BMR (W) = 4.02 x M (kg)(0.724) runs parallel to that of waders in temperate areas, but at a 20% lower elevation.

  11. Basal metabolic rate declines during long-distance migratory flight in great knots

    NARCIS (Netherlands)

    Battley, PF; Dekinga, A; Dietz, MW; Piersma, T; Tang, SX; Hulsman, K; Battley, Phil F.; Tang, Sixian

    2001-01-01

    Great Knots (Calidris tenuirostris) make one of the longest migratory flights in the avian world, flying almost 5500 km from Australia to China during northward migration. We measured basal metabolic rate (BMR) and body composition in birds before and after this flight and found that BMR decreased

  12. Avian basal metabolic rates : their association with body composition and energy expenditure in nature

    NARCIS (Netherlands)

    Daan, Serge; Masman, Dirkjan; Groenewold, Alex

    Measurements of basal metabolic rate (BMR), body water, fat, and lean dry mass of different organs were obtained in 22 bird species, ranging from 10.8 to 1,253 g body mass. Residuals of BMR (after subtracting BMR allometrically predicted from body mass) were positively correlated with residuals of

  13. Determinants of intra-specific variation in basal metabolic rate.

    Science.gov (United States)

    Konarzewski, Marek; Książek, Aneta

    2013-01-01

    Basal metabolic rate (BMR) provides a widely accepted benchmark of metabolic expenditure for endotherms under laboratory and natural conditions. While most studies examining BMR have concentrated on inter-specific variation, relatively less attention has been paid to the determinants of within-species variation. Even fewer studies have analysed the determinants of within-species BMR variation corrected for the strong influence of body mass by appropriate means (e.g. ANCOVA). Here, we review recent advancements in studies on the quantitative genetics of BMR and organ mass variation, along with their molecular genetics. Next, we decompose BMR variation at the organ, tissue and molecular level. We conclude that within-species variation in BMR and its components have a clear genetic signature, and are functionally linked to key metabolic process at all levels of biological organization. We highlight the need to integrate molecular genetics with conventional metabolic field studies to reveal the adaptive significance of metabolic variation. Since comparing gene expressions inter-specifically is problematic, within-species studies are more likely to inform us about the genetic underpinnings of BMR. We also urge for better integration of animal and medical research on BMR; the latter is quickly advancing thanks to the application of imaging technologies and 'omics' studies. We also suggest that much insight on the biochemical and molecular underpinnings of BMR variation can be gained from integrating studies on the mammalian target of rapamycin (mTOR), which appears to be the major regulatory pathway influencing the key molecular components of BMR.

  14. Metabolic rates and biochemical compositions of Apostichopus japonicus (Selenka) tissue during periods of inactivity

    Science.gov (United States)

    Bao, Jie; Dong, Shuanglin; Tian, Xiangli; Wang, Fang; Gao, Qinfeng; Dong, Yunwei

    2010-03-01

    Estivation, hibernation, and starvation are indispensable inactive states of sea cucumbers Apostichopus japonicus in nature and in culture ponds. Generally, temperature is the principal factor that induces estivation or hibernation in the sea cucumber. The present study provided insight into the physiological adaptations of A. japonicus during the three types of inactivity (hibernation, estivation, and starvation) by measuring the oxygen consumption rates ( Vo2) and biochemical compositions under laboratory conditions of low (3°C), normal (17°C) and high (24°C) temperature. The results show that the characteristics of A. japonicus in dormancy (hibernation and estivation) states were quite different from higher animals, such as fishes, amphibians, reptiles, and mammals, but more closely resembled a semi-dormant state. It was observed that the shift in the A. japonicus physiological state from normal to dormancy was a chronic rather than acute process, indicated by the gradual depression of metabolic rate. While metabolic rates declined 44.9% for the estivation group and 71.7% for the hibernation group, relative to initial rates, during the 36 d culture period, metabolic rates were not maintained at constant levels during these states. The metabolic depression processes for sea cucumbers in hibernation and estivation appeared to be a passive and an active metabolic suppression, respectively. In contrast, the metabolic rates (128.90±11.70 μg/g h) of estivating sea cucumbers were notably higher (107.85±6.31 μg/g h) than in starving sea cucumbers at 17°C, which indicated that the dormancy mechanism here, as a physiological inhibition, was not as efficient as in higher animals. Finally, the principle metabolic substrate or energy source of sea cucumbers in hibernation was lipid, whereas in estivation they mainly consumed protein in the early times and both protein and lipid thereafter.

  15. Thyroid hormones correlate with basal metabolic rate but not field metabolic rate in a wild bird species.

    Directory of Open Access Journals (Sweden)

    Jorg Welcker

    Full Text Available Thyroid hormones (TH are known to stimulate in vitro oxygen consumption of tissues in mammals and birds. Hence, in many laboratory studies a positive relationship between TH concentrations and basal metabolic rate (BMR has been demonstrated whereas evidence from species in the wild is scarce. Even though basal and field metabolic rates (FMR are often thought to be intrinsically linked it is still unknown whether a relationship between TH and FMR exists. Here we determine the relationship between the primary thyroid hormone triiodothyronine (T3 with both BMR and FMR in a wild bird species, the black-legged kittiwake (Rissa tridactyla. As predicted we found a strong and positive relationship between plasma concentrations of T3 and both BMR and mass-independent BMR with coefficients of determination ranging from 0.36 to 0.60. In contrast there was no association of T3 levels with either whole-body or mass-independent FMR (R(2 =0.06 and 0.02, respectively. In accordance with in vitro studies our data suggests that TH play an important role in modulating BMR and may serve as a proxy for basal metabolism in wild birds. However, the lack of a relationship between TH and FMR indicates that levels of physical activity in kittiwakes are largely independent of TH concentrations and support recent studies that cast doubt on a direct linkage between BMR and FMR.

  16. Thyroid Hormones Correlate with Basal Metabolic Rate but Not Field Metabolic Rate in a Wild Bird Species

    Science.gov (United States)

    Welcker, Jorg; Chastel, Olivier; Gabrielsen, Geir W.; Guillaumin, Jerome; Kitaysky, Alexander S.; Speakman, John R.; Tremblay, Yann; Bech, Claus

    2013-01-01

    Thyroid hormones (TH) are known to stimulate in vitro oxygen consumption of tissues in mammals and birds. Hence, in many laboratory studies a positive relationship between TH concentrations and basal metabolic rate (BMR) has been demonstrated whereas evidence from species in the wild is scarce. Even though basal and field metabolic rates (FMR) are often thought to be intrinsically linked it is still unknown whether a relationship between TH and FMR exists. Here we determine the relationship between the primary thyroid hormone triiodothyronine (T3) with both BMR and FMR in a wild bird species, the black-legged kittiwake (Rissa tridactyla). As predicted we found a strong and positive relationship between plasma concentrations of T3 and both BMR and mass-independent BMR with coefficients of determination ranging from 0.36 to 0.60. In contrast there was no association of T3 levels with either whole-body or mass-independent FMR (R2 = 0.06 and 0.02, respectively). In accordance with in vitro studies our data suggests that TH play an important role in modulating BMR and may serve as a proxy for basal metabolism in wild birds. However, the lack of a relationship between TH and FMR indicates that levels of physical activity in kittiwakes are largely independent of TH concentrations and support recent studies that cast doubt on a direct linkage between BMR and FMR. PMID:23437096

  17. Estimating fish swimming metrics and metabolic rates with accelerometers: the influence of sampling frequency.

    Science.gov (United States)

    Brownscombe, J W; Lennox, R J; Danylchuk, A J; Cooke, S J

    2018-06-21

    Accelerometry is growing in popularity for remotely measuring fish swimming metrics, but appropriate sampling frequencies for accurately measuring these metrics are not well studied. This research examined the influence of sampling frequency (1-25 Hz) with tri-axial accelerometer biologgers on estimates of overall dynamic body acceleration (ODBA), tail-beat frequency, swimming speed and metabolic rate of bonefish Albula vulpes in a swim-tunnel respirometer and free-swimming in a wetland mesocosm. In the swim tunnel, sampling frequencies of ≥ 5 Hz were sufficient to establish strong relationships between ODBA, swimming speed and metabolic rate. However, in free-swimming bonefish, estimates of metabolic rate were more variable below 10 Hz. Sampling frequencies should be at least twice the maximum tail-beat frequency to estimate this metric effectively, which is generally higher than those required to estimate ODBA, swimming speed and metabolic rate. While optimal sampling frequency probably varies among species due to tail-beat frequency and swimming style, this study provides a reference point with a medium body-sized sub-carangiform teleost fish, enabling researchers to measure these metrics effectively and maximize study duration. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Positron emission tomography assessment of cerebral glucose metabolic rates in autism spectrum disorder and schizophrenia.

    Science.gov (United States)

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

    2018-04-01

    Several models have been proposed to account for observed overlaps in clinical features and genetic predisposition between schizophrenia and autism spectrum disorder. This study assessed similarities and differences in topological patterns and vectors of glucose metabolism in both disorders in reference to these models. Co-registered 18 fluorodeoxyglucose PET and MRI scans were obtained in 41 schizophrenia, 25 ASD, and 55 healthy control subjects. AFNI was used to map cortical and subcortical regions of interest. Metabolic rates were compared between three diagnostic groups using univariate and multivariate repeated-measures ANOVA. Compared to controls, metabolic rates in schizophrenia subjects were decreased in the frontal lobe, anterior cingulate, superior temporal gyrus, amygdala and medial thalamic nuclei; rates were increased in the occipital cortex, hippocampus, basal ganglia and lateral thalamic nuclei. In ASD subjects metabolic rates were decreased in the parietal lobe, frontal premotor and eye-fields areas, and amygdala; rates were increased in the posterior cingulate, occipital cortex, hippocampus and basal ganglia. In relation to controls, subjects with ASD and schizophrenia showed opposite changes in metabolic rates in the primary motor and somatosensory cortex, anterior cingulate and hypothalamus; similar changes were found in prefrontal and occipital cortices, inferior parietal lobule, amygdala, hippocampus, and basal ganglia. Schizophrenia and ASD appear to be associated with a similar pattern of metabolic abnormalities in the social brain. Divergent maladaptive trade-offs, as postulated by the diametrical hypothesis of their evolutionary relationship, may involve a more circumscribed set of anterior cingulate, motor and somatosensory regions and the specific cognitive functions they subserve.

  19. 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.

  20. 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.

  1. Hexamitiasis leads to lower metabolic rates in rainbow trout Oncorhynchus mykiss (Walbaum) juveniles.

    Science.gov (United States)

    Ogut, H; Parlak, R

    2014-12-01

    This study assessed the effects of Hexamita salmonis (Moore) on metabolism of rainbow trout Oncorhynchus mykiss (Walbaum) and its effect on the host's susceptibility to infectious pancreatic necrosis virus (IPNV) after antiparasitic treatment. Rainbow trout naturally infected with H. salmonis were treated with 10 mg metronidazole kg fish(-1) per day, and their physiological recovery was assessed through measuring resting metabolism on the 7th, 14th, 21st and 28th day after treatment. In addition, we exposed the naïve fish to H. salmonis and measured the resting metabolism (oxygen consumption as mg O2 kg(-1) per hour) on the 10th, 20th and 30th day after the exposure to assess the variation in metabolic rates after infection. Significantly lower rates of metabolic activity (P trout to IPNV remained unchanged in the presence of H. salmonis. Weight loss was significantly higher (P < 0.05) in infected than that in the parasite-free fish. Fish should be examined regularly for H. salmonis and treated immediately whether found to prevent economic losses and excessive size variation. © 2013 John Wiley & Sons Ltd.

  2. Hemispherical dominance of glucose metabolic rate in the brain of the 'normal' ageing population

    NARCIS (Netherlands)

    Cutts, DA; Maguire, RP; Leenders, KL; Spyrou, NM

    2004-01-01

    In the 'normal' ageing brain a decrease in the cerebral metabolic rate has been determined across many brain regions. This study determines whether age differences would affect metabolic rates in regions and different hemispheres of the brain. The regional metabolic rate of glucose (rCMRGlu) was

  3. Energy metabolism and the metabolic syndrome: does a lower basal metabolic rate signal recovery following weight loss?

    Science.gov (United States)

    Soares, Mario J; Cummings, Nicola K; Ping-Delfos, Wendy L Chan She

    2011-01-01

    To determine whether basal metabolic rate (BMR) was causally related to MetS, and to study the role of gender in this relationship. Seventy-two Caucasian subjects (43 women, 29 men) had changes in basal metabolic rate (BMR), carbohydrate oxidation rate (COR), fat oxidation rate (FOR) and prevalence of the metabolic syndrome (MetS) assessed in response to weight loss. There was a significant gender×MetS interaction in BMR at the start. Women with MetS had higher adjusted BMR, whilst men with MetS had lower adjusted BMR than their respective counterparts. Weight loss resulted in a significant decrease in fat mass (-5.2±0.31 kg, p=0.001), fat free mass (-2.3±0.27 kg, p=0.001), BMR (-549±58 kJ/d, p=0.001) and a decreased proportion of MetS (22/72, χ(2)=0.005). Subjects who recovered from MetS after weight loss (RMS) had ∼250 kJ/d significantly lower adjusted BMR compared to those who were never MetS (NMS, p=0.046) and those who still had MetS (MetS+, p=0.047). Regression analysis showed that change (Δ) in BMR was best determined by Δglucose×gender interaction (r(2)=23%), ΔFOR (r(2)=20.3%), ΔCOR (r(2)=19.4%) and Δtriglycerides (r(2)=7.8%). There is a sexual dimorphism of BMR in MetS. Overall, the data support the notion that alterations in BMR may be central to the etiopathogenesis of MetS. Copyright © 2012 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  4. 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......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....... 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...

  5. Chapter 15. Measurement of the main calcium metabolism processes

    International Nuclear Information System (INIS)

    Milhaud, G.

    1975-01-01

    A method of measuring the chief calcium metabolism processes in man is described and is based on the following techniques and theory: intraveinous injection of 45 Ca; determination of the specific radioactivity of serum calcium, total radioactivity of urine and stools, ingested and excreted calcium; mathematical analysis of the specific radioactivity decay curve for serum calcium. The following data were obtained in this way: intestinal absorption fraction of calcium in the chemical state in which it is found in foods; quantity of calcium excreted by the intestin, as distinct from the non-absorbed fraction; physiological turnover rates in the skeleton by osteolysis and osteoblastosis; mass of rapidly exchangeable calcium in the organism, i.e. the calcium pool; rates of exchange with serum calcium of calcium from the different pool components, mass of bone calcium subjected to recrystallisation. Some applications of the method in man and the verification of the theory in rats are reported [fr

  6. 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

  7. Measurement of inertial confinement fusion reaction rate

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Tang Daorun; Liu Shenye; Huang Tianxuan; Liu Yonggang; Xu Tao; Chen Ming; Mei Yu

    2011-01-01

    Fusion reaction rate is an important parameter for measuring compression during the implosion in inertial confinement fusion experiment. We have developed a system for fusion reaction history measurement with high temporal resolution. The system is composed of plastic scintillator and nose cone, optical system and streak camera. We have applied this system on the SG-III prototype for fusion reaction rate measuring. For the first time, fusion reaction rate history have been measured for deuterium-tritium filled targets with neutrons yields about 10 10 . We have analyzed possible influence factor during fusion reaction rate measuring. It indicates that the instrument measures fusion reaction bang time at temporal resolutions as low as 30 ps.(authors)

  8. Measurement of metabolism of worker ants by using the elimination of caesium-134

    International Nuclear Information System (INIS)

    Nielsen, M.G.; Jensen, T.F.

    1977-01-01

    In order to find a method for measuring field metabolism of worker ants the elimination of 134 Cs by two ant species has been investigated. Equations relating temperature to radiocaesium elimination and metabolism have been found. From these equations the relationship between elimination and metabolism is calculated. Consequently, the elimination of the isotope can be used for measuring metabolism. A pilot field experiment with Lasius alienus (Foerst.) reveals that the traditional methods of estimating field metabolism give values which are considerably lower than the value based on caesium elimination rate. This difference is supposed to be mainly due to greater motor activity of the animals in the field. Consequently, the value of the caesium elimination method is closer to the 'true' value of field metabolism. (orig.) [de

  9. Dose-response relationship between probability of pathologic tumor control and glucose metabolic rate measured with FDG PET after preoperative chemoradiotherapy in locally advanced non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Choi, Noah C.; Fischman, Alan J.; Niemierko, Andrzej; Ryu, Jin-Sook; Lynch, Thomas; Wain, John; Wright, Cameron; Fidias, Panos; Mathisen, Douglas

    2002-01-01

    Purpose: To determine the dose-response relationship between the probability of tumor control on the basis of pathologic tumor response (pTCP) and the residual metabolic rate of glucose (MRglc) in response to preoperative chemoradiotherapy in locally advanced non-small-cell lung cancer and to define the level of residual MRglc that corresponds to pTCP 50% and pTCP ≥95%. Methods and Materials: Quantitative dynamic 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography was performed to measure regional MRglc at the primary lesion before and 2 weeks after preoperative chemoradiotherapy in an initial group of 13 patients with locally advanced NSCLC. A simplified kinetic method was developed subsequently from the initial dynamic study and used in the subsequent 16 patients. The preoperative radiotherapy programs consisted of (1) a split course of 42 Gy in 28 fractions within a period of 28 days using a twice-daily treatment schedule for Stage IIIA(N2) NSCLC (n=18) and (2) standard once-daily radiation schedule of 45-63 Gy in 25-35 fractions during a 5-7-week period (n=11). The preoperative chemotherapy regimens included two cycles of cisplatin, vinblastine, and 5-fluorouracil (n=24), cisplatin and etoposide (n=2), and cisplatin, Taxol, and 5-fluorouracil (n=3). Patients free of tumor progression after preoperative chemoradiotherapy underwent surgery. The degree of residual MRglc measured 2 weeks after preoperative chemoradiotherapy and 2 weeks before surgery was correlated with the pathologic tumor response. The relationship between MRglc and pTCP was modeled using logistic regression. Results: Of 32 patients entered into the study, 29 (16 men and 13 women; 30 lesions) were evaluated for the correlation between residual MRglc and pathologic tumor response. Three patients did not participate in the second study because of a steady decline in general condition. The median age was 60 years (range 42-78). One of the 29 patients had two separate lesions, and

  10. 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.

  11. 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) (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. Environment, migratory tendency, phylogeny and basal metabolic rate in birds.

    Directory of Open Access Journals (Sweden)

    Walter Jetz

    Full Text Available Basal metabolic rate (BMR represents the minimum maintenance energy requirement of an endotherm and has far-reaching consequences for interactions between animals and their environments. Avian BMR exhibits considerable variation that is independent of body mass. Some long-distance migrants have been found to exhibit particularly high BMR, traditionally interpreted as being related to the energetic demands of long-distance migration. Here we use a global dataset to evaluate differences in BMR between migrants and non-migrants, and to examine the effects of environmental variables. The BMR of migrant species is significantly higher than that of non-migrants. Intriguingly, while the elevated BMR of migrants on their breeding grounds may reflect the metabolic machinery required for long-distance movements, an alternative (and statistically stronger explanation is their occupation of predominantly cold high-latitude breeding areas. Among several environmental predictors, average annual temperature has the strongest effect on BMR, with a 50% reduction associated with a 20 degrees C gradient. The negative effects of temperature variables on BMR hold separately for migrants and non-migrants and are not due their different climatic associations. BMR in migrants shows a much lower degree of phylogenetic inertia. Our findings indicate that migratory tendency need not necessarily be invoked to explain the higher BMR of migrants. A weaker phylogenetic signal observed in migrants supports the notion of strong phenotypic flexibility in this group which facilitates migration-related BMR adjustments that occur above and beyond environmental conditions. In contrast to the findings of previous analyses of mammalian BMR, primary productivity, aridity or precipitation variability do not appear to be important environmental correlates of avian BMR. The strong effects of temperature-related variables and varying phylogenetic effects reiterate the importance of

  13. 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 ( Poecile atricapillus ). 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. PMID:23840843

  14. Does basal metabolic rate predict weight gain?12

    Science.gov (United States)

    Anthanont, Pimjai; Jensen, Michael D

    2016-01-01

    Background: Some previous studies have indicated that a low basal metabolic rate (BMR) is an independent predictor of future weight gain, but low rates of follow-up and highly select populations may limit the ability to generalize the results. Objective: We assessed whether adults with a low BMR gain more weight than do adults with a high BMR who are living in a typical Western environment. Design: We extracted BMR, body-composition, demographic, and laboratory data from electronic databases of 757 volunteers who were participating in our research protocols at the Mayo Clinic between 1995 and 2012. Research study volunteers were always weight stable, had no acute illnesses and no confounding medication use, and were nonsmokers. The top and bottom 15th percentiles of BMR, adjusted for fat-free mass (FFM), fat mass, age, and sex, were identified. Follow-up electronic medical record system data were available for 163 subjects, which allowed us to determine their subsequent weight changes for ≥3 y (mean: ∼9.7 y). Results: By definition, the BMR was different in the high-BMR group (2001 ± 317 kcal/d; n = 86) than in the low-BMR group (1510 ± 222 kcal/d; n = 77), but they were comparable with respect to age, body mass index, FFM, and fat mass. Rates of weight gain were not greater in the bottom BMR group (0.3 ± 1.0 kg/y) than in the top BMR group (0.5 ± 1.5 kg/y) (P = 0.17). Conclusion: Adults with low BMRs did not gain more weight than did adults with high BMRs, implying that habitual differences in food intake or activity counterbalance variations in BMR as a risk factor for weight gain in a typical Western population. PMID:27581474

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

    OpenAIRE

    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 cel...

  16. Glass dissolution rate measurement and calculation revisited

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Maxime, E-mail: maxime.fournier@cea.fr [CEA, DEN, DTCD, SECM, F-30207, Bagnols sur Cèze (France); Ull, Aurélien; Nicoleau, Elodie [CEA, DEN, DTCD, SECM, F-30207, Bagnols sur Cèze (France); Inagaki, Yaohiro [Department of Applied Quantum Physics & Nuclear Engineering, Kyushu University, Fukuoka, 819-0395 (Japan); Odorico, Michaël [ICSM-UMR5257 CEA/CNRS/UM2/ENSCM, Site de Marcoule, BP17171, F-30207, Bagnols sur Cèze (France); Frugier, Pierre; Gin, Stéphane [CEA, DEN, DTCD, SECM, F-30207, Bagnols sur Cèze (France)

    2016-08-01

    Aqueous dissolution rate measurements of nuclear glasses are a key step in the long-term behavior study of such waste forms. These rates are routinely normalized to the glass surface area in contact with solution, and experiments are very often carried out using crushed materials. Various methods have been implemented to determine the surface area of such glass powders, leading to differing values, with the notion of the reactive surface area of crushed glass remaining vague. In this study, around forty initial dissolution rate measurements were conducted following static and flow rate (SPFT, MCFT) measurement protocols at 90 °C, pH 10. The international reference glass (ISG), in the forms of powders with different particle sizes and polished monoliths, and soda-lime glass beads were examined. Although crushed glass grains clearly cannot be assimilated with spheres, it is when using the samples geometric surface (S{sub geo}) that the rates measured on powders are closest to those found for monoliths. Overestimation of the reactive surface when using the BET model (S{sub BET}) may be due to small physical features at the atomic scale—contributing to BET surface area but not to AFM surface area. Such features are very small compared with the thickness of water ingress in glass (a few hundred nanometers) and should not be considered in rate calculations. With a S{sub BET}/S{sub geo} ratio of 2.5 ± 0.2 for ISG powders, it is shown here that rates measured on powders and normalized to S{sub geo} should be divided by 1.3 and rates normalized to S{sub BET} should be multiplied by 1.9 in order to be compared with rates measured on a monolith. The use of glass beads indicates that the geometric surface gives a good estimation of glass reactive surface if sample geometry can be precisely described. Although data clearly shows the repeatability of measurements, results must be given with a high uncertainty of approximately ±25%. - Highlights: • Initial dissolution

  17. 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

    This investigation evaluated the effects of nanoparticles of silver (AgNano) and gold (AuNano) on metabolic rate (O(2) consumption, CO(2) production and heat production-HP) and the development of embryos from different breeds of broiler and layer chicken. Gaseous exchange was measured in an open......-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...

  18. Mechanistic model of mass-specific basal metabolic rate: evaluation in healthy young adults.

    Science.gov (United States)

    Wang, Z; Bosy-Westphal, A; Schautz, B; Müller, M

    2011-12-01

    Mass-specific basal metabolic rate (mass-specific BMR), defined as the resting energy expenditure per unit body mass per day, is an important parameter in energy metabolism research. However, a mechanistic explanation for magnitude of mass-specific BMR remains lacking. The objective of the present study was to validate the applicability of a proposed mass-specific BMR model in healthy adults. A mechanistic model was developed at the organ-tissue level, mass-specific BMR = Σ( K i × F i ), where Fi is the fraction of body mass as individual organs and tissues, and K i is the specific resting metabolic rate of major organs and tissues. The Fi values were measured by multiple MRI scans and the K i values were suggested by Elia in 1992. A database of healthy non-elderly non-obese adults (age 20 - 49 yrs, BMI BMR of all subjects was 21.6 ± 1.9 (mean ± SD) and 21.7 ± 1.6 kcal/kg per day, respectively. The measured mass-specific BMR was correlated with the predicted mass-specific BMR (r = 0.82, P BMR, versus the average of measured and predicted mass-specific BMR. In conclusion, the proposed mechanistic model was validated in non-elderly non-obese adults and can help to understand the inherent relationship between mass-specific BMR and body composition.

  19. HANARO core channel flow-rate measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heon Il; Chae, Hee Tae; Im, Don Soon; Kim, Seon Duk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-01

    HANARO core consists of 23 hexagonal flow tubes and 16 cylindrical flow tubes. To get the core flow distribution, we used 6 flow-rate measuring dummy fuel assemblies (instrumented dummy fuel assemblies). The differential pressures were measured and converted to flow-rates using the predetermined relationship between AP and flow-rate for each instrumented dummy fuel assemblies. The flow-rate for the cylindrical flow channels shows +-7% relative errors and that for the hexagonal flow channels shows +-3.5% relative errors. Generally the flow-rates of outer core channels show smaller values compared to those of inner core. The channels near to the core inlet pipe and outlet pipes also show somewhat lower flow-rates. For the lower flow channels, the thermal margin was checked by considering complete linear power histories. From the experimental results, the gap flow-rate was estimated to be 49.4 kg/s (cf. design flow of 50 kg/s). 15 tabs., 9 figs., 10 refs. (Author) .new.

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

    Indian Academy of Sciences (India)

    MADU

    3.1 Effect of vitamin C administration on basal metabolic rate. The basal metabolic rate values in diabetic rats and control are presented in figure 1. The basal metabolic rate (BMR) in diabetic rats was 1.19 ± 0.15 ml/h/g, while the BMR in control rats was 0.76 ± 0.89 ml/h/g. The BMR value in diabetic rats treated with vitamin ...

  1. Metabolic clearance and production rates of human growth hormone

    Science.gov (United States)

    Taylor, Andrew L.; Finster, Joseph L.; Mintz, Daniel H.

    1969-01-01

    The metabolic clearance rate (MCR) of human growth hormone (HGH) was determined by the constant infusion to equilibrium technique utilizing HGH-125I. 22 control subjects had a MCR of 229 ±52 ml/min (mean ±SD). No difference was evident between sexes, or between various age groups. Patients with acromegaly demonstrated normal MCR's. Moreover, acute elevations of plasma growth hormone concentrations in normal subjects did not alter the MCR of HGH. The MCR was relatively constant from day to day and within the day when subjects were evaluated in the supine position. In contrast, the assumption of the upright position was associated with a mean 24% decrease in the MCR. These results were contrasted with the MCR of HGH observed in a small number of patients with altered thyroid function or diabetes mellitus. In six patients with hypothyroidism the MCR (131 ±36 ml/min) was significantly decreased (P < 0.001); whereas the MCR in eight patients with hyperthyroidism (240 ±57 ml/min) did not differ from control subjects. The MCR in eight patients with insulin-independent diabetes mellitus (IID) (185 ±41 ml/min) and in eight patients with insulin-dependent diabetes mellitus (IDD) (136 ±31 ml/min) were significantly different from control subjects (P = < 0.05 and P = < 0.001, respectively). These data were interpreted to indicate that the plasma HGH-removing mechanism(s) is not saturated at physiologic plasma HGH levels, that plasma HGH levels alone may not permit distinction between variations in pituitary release of the hormone and its rate of clearance from the plasma, and that the estimation of the MCR of HGH may help clarify the mechanism of abnormal plasma HGH responses to various stimuli. Production rates of HGH (PR) in control subjects (347 ±173 mμg/min) were contrasted with hyperthyroid patients (529 ±242 mμg/min, P < 0.05), hypothyroid patients (160 ±69 mμg/min, P < 0.02), IID (245 ±100 mμg/min, NS), and IDD (363 ±153 mμg/min, NS). Considerable

  2. [Proceeding: Production rate, metabolic clearance rate and mean plasma concentration of cortisol in hyperthyroidism (author's transl)].

    Science.gov (United States)

    Linquette, M; Lefebvre, J; Racadot, A; Cappoen, J P

    1975-01-01

    The adrenocortical function was studied in 23 patients with hyperthyroidism and compared with a group of 15 normal subjects. Parameters of adrenal function were determined with 1,2(3)H-cortisol. The half-life of cortisol is significantly shortened in hyperthyroidism, as compared to normal subjects (49,5 +/- 6,6 min vs 68,3 +/- 10,5 min) and metabolic clearance rate is increased (418,5 +/- 89,5 L/24 h vs 237,5 +/- 48,5 L/24 h, for normal subjects). The production rate of cortisol, calculated from specific and cumulate activities of THE and THF is increased in hyperthyroidism expressed as mg/24 h or mg/m2/24 h (respectively : 26,7 +/- 7,8 mg/24 h vs 15,7 +/- 3 mg/24 h and 16,9 +/- 4,6 mg/m2/24 h vs 9,5 +/- 1,8 mg/m2/24 h). The mean plasma concentration, calculated as the radio (see article) is not statiscally different in hyperthyroid and normal subjects (6,8 +/- 2,1 microg/100 ml vs 7,3 +/- 1,9 microg/100 ml). 7 patients were reinvestigated after treatment of thyrotoxicosis when they were clinically and biologically in euthyroid state. All the values were normalized, without statistically significant difference from control (T 1/2 = 65,4 +/- 18 min, Metb Cl. Rate : 255 +/- 64,5 L/24 h, production rate : 15,6 +/- 1,8 mg/24 h and 9 +/- 1,4 mg/m2/24 h. mean plasma concentration : 6,8 +/- 2,8 microg/100 ml). Shortened cortisol half life, increased metabolic clearance rate and production rate, and normal mean plasma concentration have been reported in hyperthyroidism (Peterson, Copinschi, Gallagher). These changes, secondary to thyroid hormone excess, are the consequences of increased hepatic catabolism of cortisol. The activity of 11 OH steroid deshydrogenase is increased, as demonstrated by increased ratio (see article) in normal subjects (0,001 less than p less than 0,005). There is a high proportion of 17 kéto metabolites (E, DHE, THE) whose feed-back effect is weak as compared to 17 OH metabolites (F, DHF, THF). The hypothalamo-hypophyso-adrenal system is

  3. Expensive Brains: “Brainy” Rodents have Higher Metabolic Rate

    Science.gov (United States)

    Sobrero, Raúl; May-Collado, Laura J.; Agnarsson, Ingi; Hernández, Cristián E.

    2011-01-01

    Brains are the centers of the nervous system of animals, controlling the organ systems of the body and coordinating responses to changes in the ecological and social environment. The evolution of traits that correlate with cognitive ability, such as relative brain size is thus of broad interest. Brain mass relative to body mass (BM) varies among mammals, and diverse factors have been proposed to explain this variation. A recent study provided evidence that energetics play an important role in brain evolution (Isler and van Schaik, 2006). Using composite phylogenies and data drawn from multiple sources, these authors showed that basal metabolic rate (BMR) correlates with brain mass across mammals. However, no such relationship was found within rodents. Here we re-examined the relationship between BMR and brain mass within Rodentia using a novel species-level phylogeny. Our results are sensitive to parameter evaluation; in particular how species mass is estimated. We detect no pattern when applying an approach used by previous studies, where each species BM is represented by two different numbers, one being the individual that happened to be used for BMR estimates of that species. However, this approach may compromise the analysis. When using a single value of BM for each species, whether representing a single individual, or available species mean, our findings provide evidence that brain mass (independent of BM) and BMR are correlated. These findings are thus consistent with the hypothesis that large brains evolve when the payoff for increased brain mass is greater than the energetic cost they incur. PMID:21811456

  4. Experiences in integrated leak rate measurements

    International Nuclear Information System (INIS)

    Shirk, R.E.

    1982-01-01

    During a hypothetical design basis accident for nuclear power plants, the reactor containment system is relied upon to maintain radioactive exposure limits below acceptable limits. Integrated leak rate testing is a means of verifying that the leakage of radioactivity material from the reactor containment will be below allowable limits. Leakage rate computations are based on the ideal gas law. The absolute method of leakage rate testing utilizing mass point method of data analysis is recommended. Integrated leak rate testing data is obtained from pressure, drybulb temperature, dewpoint temperature, and flow measuring systems. Test data does not support the usual leakage (flow) - pressure square root relationship. The major source of potential leakage from the reactor containment is reactor containment isolation valves

  5. Low resting metabolic rate in exercise-associated amenorrhea is not due to a reduced proportion of highly active metabolic tissue compartments.

    Science.gov (United States)

    Koehler, Karsten; Williams, Nancy I; Mallinson, Rebecca J; Southmayd, Emily A; Allaway, Heather C M; De Souza, Mary Jane

    2016-08-01

    Exercising women with menstrual disturbances frequently display a low resting metabolic rate (RMR) when RMR is expressed relative to body size or lean mass. However, normalizing RMR for body size or lean mass does not account for potential differences in the size of tissue compartments with varying metabolic activities. To explore whether the apparent RMR suppression in women with exercise-associated amenorrhea is a consequence of a lower proportion of highly active metabolic tissue compartments or the result of metabolic adaptations related to energy conservation at the tissue level, RMR and metabolic tissue compartments were compared among exercising women with amenorrhea (AMEN; n = 42) and exercising women with eumenorrheic, ovulatory menstrual cycles (OV; n = 37). RMR was measured using indirect calorimetry and predicted from the size of metabolic tissue compartments as measured by dual-energy X-ray absorptiometry (DEXA). Measured RMR was lower than DEXA-predicted RMR in AMEN (1,215 ± 31 vs. 1,327 ± 18 kcal/day, P < 0.001) but not in OV (1,284 ± 24 vs. 1,252 ± 17, P = 0.16), resulting in a lower ratio of measured to DEXA-predicted RMR in AMEN (91 ± 2%) vs. OV (103 ± 2%, P < 0.001). AMEN displayed proportionally more residual mass (P < 0.001) and less adipose tissue (P = 0.003) compared with OV. A lower ratio of measured to DXA-predicted RMR was associated with lower serum total triiodothyronine (ρ = 0.38, P < 0.001) and leptin (ρ = 0.32, P = 0.004). Our findings suggest that RMR suppression in this population is not the result of a reduced size of highly active metabolic tissue compartments but is due to metabolic and endocrine adaptations at the tissue level that are indicative of energy conservation.

  6. Instantaneous Metabolic Cost of Walking: Joint-Space Dynamic Model with Subject-Specific Heat Rate.

    Directory of Open Access Journals (Sweden)

    Dustyn Roberts

    Full Text Available A subject-specific model of instantaneous cost of transport (ICOT is introduced from the joint-space formulation of metabolic energy expenditure using the laws of thermodynamics and the principles of multibody system dynamics. Work and heat are formulated in generalized coordinates as functions of joint kinematic and dynamic variables. Generalized heat rates mapped from muscle energetics are estimated from experimental walking metabolic data for the whole body, including upper-body and bilateral data synchronization. Identified subject-specific energetic parameters-mass, height, (estimated maximum oxygen uptake, and (estimated maximum joint torques-are incorporated into the heat rate, as opposed to the traditional in vitro and subject-invariant muscle parameters. The total model metabolic energy expenditure values are within 5.7 ± 4.6% error of the measured values with strong (R2 > 0.90 inter- and intra-subject correlations. The model reliably predicts the characteristic convexity and magnitudes (0.326-0.348 of the experimental total COT (0.311-0.358 across different subjects and speeds. The ICOT as a function of time provides insights into gait energetic causes and effects (e.g., normalized comparison and sensitivity with respect to walking speed and phase-specific COT, which are unavailable from conventional metabolic measurements or muscle models. Using the joint-space variables from commonly measured or simulated data, the models enable real-time and phase-specific evaluations of transient or non-periodic general tasks that use a range of (aerobic energy pathway similar to that of steady-state walking.

  7. Problems in continuous dose rate measurement

    International Nuclear Information System (INIS)

    Yoshioka, Mitsuo

    1983-01-01

    The system of continuous dose rate measurement in Fukui Prefecture is described. A telemeter system was constructed in October, 1976, and it has been operated since 1977. Observation has been made at 11 observation stations in the Prefecture. In addition to the continuous measurement of dose rate by using NaI(T1)-DBM systems, the ionization chambers for high dose rate were installed, and also meteorological data have been collected. The detectors are covered with 1 mm thick aluminum designed so that the absorption of external radiation is kept as small as possible. To keep the environmental temperature of the detectors constant, constant temperature wind blow is made. With these consideration, the measurement of Xe-133 is possible, and the standard deviation of yearly dose is around 0.4 mR/Y. By measuring DBM transmission rate, the contribution of Xe-133, which comes from the exhaust pumps in power plants, can be detected. The problems of this system are as follows. First of all, the characteristics of the system must meet the purpose of dose monitoring. The system must detect the dose less than the target value to be achieved. The second is the selection of measuring systems to be set. The system is still not unified, and it is difficult to exchange data between different stations. Finally, the method of data analysis is not yet unified. Manuals or guide-books for this purpose are necessary for the mutual comparison of the data from the stations in different districts. (Kato, T.)

  8. Increasing Winter Maximal Metabolic Rate Improves Intrawinter Survival in Small Birds.

    Science.gov (United States)

    Petit, Magali; Clavijo-Baquet, Sabrina; Vézina, François

    Small resident bird species living at northern latitudes increase their metabolism in winter, and this is widely assumed to improve their chances of survival. However, the relationship between winter metabolic performance and survival has yet to be demonstrated. Using capture-mark-recapture, we followed a population of free-living black-capped chickadees (Poecile atricapillus) over 3 yr and evaluated their survival probability within and among winters. We also measured the size-independent body mass (M s ), hematocrit (Hct), basal metabolic rate (BMR), and maximal thermogenic capacity (Msum) and investigated how these parameters influenced survival within and among winters. Results showed that survival probability was high and constant both within (0.92) and among (0.96) winters. They also showed that while M s , Hct, and BMR had no significant influence, survival was positively related to Msum-following a sigmoid relationship-within but not among winter. Birds expressing an Msum below 1.26 W (i.e., similar to summer levels) had a winter. Our data therefore suggest that black-capped chickadees that are either too slow or unable to adjust their phenotype from summer to winter have little chances of survival and thus that seasonal upregulation of metabolic performance is highly beneficial. This study is the first to document in an avian system the relationship between thermogenic capacity and winter survival, a proxy of fitness.

  9. The scaling of maximum and basal metabolic rates of mammals and birds

    Science.gov (United States)

    Barbosa, Lauro A.; Garcia, Guilherme J. M.; da Silva, Jafferson K. L.

    2006-01-01

    Allometric scaling is one of the most pervasive laws in biology. Its origin, however, is still a matter of dispute. Recent studies have established that maximum metabolic rate scales with an exponent larger than that found for basal metabolism. This unpredicted result sets a challenge that can decide which of the concurrent hypotheses is the correct theory. Here, we show that both scaling laws can be deduced from a single network model. Besides the 3/4-law for basal metabolism, the model predicts that maximum metabolic rate scales as M, maximum heart rate as M, and muscular capillary density as M, in agreement with data.

  10. Heartbeat Rate Measurement from Facial Video

    DEFF Research Database (Denmark)

    Haque, Mohammad Ahsanul; Irani, Ramin; Nasrollahi, Kamal

    2016-01-01

    Heartbeat Rate (HR) reveals a person’s health condition. This paper presents an effective system for measuring HR from facial videos acquired in a more realistic environment than the testing environment of current systems. The proposed method utilizes a facial feature point tracking method...... by combining a ‘Good feature to track’ and a ‘Supervised descent method’ in order to overcome the limitations of currently available facial video based HR measuring systems. Such limitations include, e.g., unrealistic restriction of the subject’s movement and artificial lighting during data capture. A face...

  11. Metabolism of the intervertebral disc: effects of low levels of oxygen, glucose, and pH on rates of energy metabolism of bovine nucleus pulposus cells.

    Science.gov (United States)

    Bibby, Susan R S; Jones, Deborah A; Ripley, Ruth M; Urban, Jill P G

    2005-03-01

    In vitro measurements of metabolic rates of isolated bovine nucleus pulposus cells at varying levels of oxygen, glucose, and pH. To obtain quantitative information on the interactions between oxygen and glucose concentrations and pH, and the rates of oxygen and glucose consumption and lactic acid production, for disc nucleus cells. Disc cells depend on diffusion from blood vessels at the disc margins for supply of nutrients. Loss of supply is thought to lead to disc degeneration, but how loss of supply affects nutrient concentrations in the disc is not known; nutrient concentrations within discs can normally only be calculated, because concentration measurements are invasive. However, realistic predictions cannot be made until there are data from measurements of metabolic rates at conditions found in the disc in vivo, i.e., at low levels of oxygen, glucose, and pH. A metabolism chamber was designed to allow simultaneous recording of oxygen and glucose concentrations and of pH. These concentrations were measured electrochemically with custom-built glucose and oxygen sensors; lactic acid was measured biochemically. Bovine nucleus pulposus cells were isolated and inserted into the chamber, and simultaneous rates of oxygen and glucose consumption and of lactic acid production were measured over a range of glucose, oxygen, and pH levels. There were strong interactions between rates of metabolism and oxygen consumption and pH. At atmospheric oxygen levels, oxygen consumption rate at pH 6.2 was 32% of that at pH 7.4. The rate fell by 60% as oxygen concentration was decreased from 21 to 5% at pH 7.4, but only by 20% at pH 6.2. Similar interactions were seen for lactic acid production and glucose consumption rates; we found that glycolysis rates fell at low oxygen and glucose concentrations and low pH. Equations were derived that satisfactorily predict the effect of nutrient and metabolite concentrations on rates of lactic acid production rate and oxygen consumption. Disc

  12. 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

    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 with th...

  13. Measuring Biological Age via Metabonomics: The Metabolic Age Score.

    Science.gov (United States)

    Hertel, Johannes; Friedrich, Nele; Wittfeld, Katharina; Pietzner, Maik; Budde, Kathrin; Van der Auwera, Sandra; Lohmann, Tobias; Teumer, Alexander; Völzke, Henry; Nauck, Matthias; Grabe, Hans Jörgen

    2016-02-05

    Chronological age is one of the most important risk factors for adverse clinical outcome. Still, two individuals at the same chronological age could have different biological aging states, leading to different individual risk profiles. Capturing this individual variance could constitute an even more powerful predictor enhancing prediction in age-related morbidity. Applying a nonlinear regression technique, we constructed a metabonomic measurement for biological age, the metabolic age score, based on urine data measured via (1)H NMR spectroscopy. We validated the score in two large independent population-based samples by revealing its significant associations with chronological age and age-related clinical phenotypes as well as its independent predictive value for survival over approximately 13 years of follow-up. Furthermore, the metabolic age score was prognostic for weight loss in a sample of individuals who underwent bariatric surgery. We conclude that the metabolic age score is an informative measurement of biological age with possible applications in personalized medicine.

  14. 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…

  15. Metabolic rates are significantly lower in abyssal Holothuroidea than in shallow-water Holothuroidea

    Science.gov (United States)

    van Oevelen, Dick

    2018-01-01

    Recent analyses of metabolic rates in fishes, echinoderms, crustaceans and cephalopods have concluded that bathymetric declines in temperature- and mass-normalized metabolic rate do not result from resource-limitation (e.g. oxygen or food/chemical energy), decreasing temperature or increasing hydrostatic pressure. Instead, based on contrasting bathymetric patterns reported in the metabolic rates of visual and non-visual taxa, declining metabolic rate with depth is proposed to result from relaxation of selection for high locomotory capacity in visual predators as light diminishes. Here, we present metabolic rates of Holothuroidea, a non-visual benthic and benthopelagic echinoderm class, determined in situ at abyssal depths (greater than 4000 m depth). Mean temperature- and mass-normalized metabolic rate did not differ significantly between shallow-water (less than 200 m depth) and bathyal (200–4000 m depth) holothurians, but was significantly lower in abyssal (greater than 4000 m depth) holothurians than in shallow-water holothurians. These results support the dominance of the visual interactions hypothesis at bathyal depths, but indicate that ecological or evolutionary pressures other than biotic visual interactions contribute to bathymetric variation in holothurian metabolic rates. Multiple nonlinear regression assuming power or exponential models indicates that in situ hydrostatic pressure and/or food/chemical energy availability are responsible for variation in holothurian metabolic rates. Consequently, these results have implications for modelling deep-sea energetics and processes. PMID:29892403

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

    African Journals Online (AJOL)

    user

    2016-10-27

    Oct 27, 2016 ... maximum aerobic metabolic rate (MMR) is proportional to the fractal extent ... metabolic rate with body mass can be obtained by taking body .... blood takes place. ..... MMR and BMR is that MMR is owing mainly to respiration in skeletal .... the spectra of surface area scaling strategies of cells and organisms:.

  17. Environmental and genetic influences on flight metabolic rate in the honey bee, Apis mellifera.

    Science.gov (United States)

    Harrison, Jon F; Fewell, Jennifer H

    2002-10-01

    Flying honey bees demonstrate highly variable metabolic rates. The lowest reported values (approximately 0.3 Wg(-1)) occur in tethered bees generating the minimum lift to support their body weight, free-flying 2-day old bees, winter bees, or bees flying at high air temperatures (45 degrees C). The highest values (approximately 0.8 Wg(-1)) occur in foragers that are heavily loaded or flying in low-density air. In different studies, flight metabolic rate has increased, decreased, or remained constant with air temperature. Current research collectively suggests that this variation occurs because flight metabolic rates decrease at thorax temperatures above or below 38 degrees C. At 30 degrees C, approximately 30% of colonial energy is spent during typical foraging, so variation in flight metabolic rate can strongly affect colony-level energy balance. Higher air temperatures tend to increase colonial net gain rates, efficiencies and honey storage rates due to lower metabolic rates during flight and in the hive. Variation in flight metabolism has a clear genetic basis. Different genetic strains of honey bees often differ in flight metabolic rate, and these differences in flight physiology can be correlated with foraging effort, suggesting a possible pathway for selection effects on flight metabolism.

  18. High dose rate brachytherapy source measurement intercomparison.

    Science.gov (United States)

    Poder, Joel; Smith, Ryan L; Shelton, Nikki; Whitaker, May; Butler, Duncan; Haworth, Annette

    2017-06-01

    This work presents a comparison of air kerma rate (AKR) measurements performed by multiple radiotherapy centres for a single HDR 192 Ir source. Two separate groups (consisting of 15 centres) performed AKR measurements at one of two host centres in Australia. Each group travelled to one of the host centres and measured the AKR of a single 192 Ir source using their own equipment and local protocols. Results were compared to the 192 Ir source calibration certificate provided by the manufacturer by means of a ratio of measured to certified AKR. The comparisons showed remarkably consistent results with the maximum deviation in measurement from the decay-corrected source certificate value being 1.1%. The maximum percentage difference between any two measurements was less than 2%. The comparisons demonstrated the consistency of well-chambers used for 192 Ir AKR measurements in Australia, despite the lack of a local calibration service, and served as a valuable focal point for the exchange of ideas and dosimetry methods.

  19. Metabolic rate and gross efficiency at high work rates in world class and national level sprint skiers.

    Science.gov (United States)

    Sandbakk, Øyvind; Holmberg, Hans-Christer; Leirdal, Stig; Ettema, Gertjan

    2010-06-01

    The present study investigated metabolic rate (MR) and gross efficiency (GE) at moderate and high work rates, and the relationships to gross kinematics and physical characteristics in elite cross-country skiers. Eight world class (WC) and eight national level (NL) male sprint cross-country skiers performed three 5-min stages using the skating G3 technique, whilst roller skiing on a treadmill. GE was calculated by dividing work rate by MR. Work rate was calculated as the sum of power against gravity and frictional rolling forces. MR was calculated using gas exchange and blood lactate values. Gross kinematics, i.e. cycle length (CL) and cycle rate (CR) were measured by video analysis. Furthermore, the skiers were tested for time to exhaustion (TTE), peak oxygen uptake (VO(2peak)), and maximal speed (V(max)) on the treadmill, and maximal strength in the laboratory. Individual performance level in sprint skating was determined by FIS points. WC skiers did not differ in aerobic MR, but showed lower anaerobic MR and higher GE than NL skiers at a given speed (all P higher V(max) and TTE (all P better technique and to technique-specific power.

  20. 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).

  1. Carbon conversion and metabolic rate in two marine sponges

    NARCIS (Netherlands)

    Koopmans, M.; Van Rijswijk, P.; Martens, D.; 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

  2. Metabolic rate and its relationship with ascites in chicken genotypes

    NARCIS (Netherlands)

    Malan, D.D.; Scheele, C.W.; Buyse, J.; Kwakernaak, C.; Siebrits, F.K.; Klis, van der J.D.; Decuypere, E.

    2003-01-01

    This review addresses the suggestion that the decline in dairy reproductive performance, as increasingly observed these days, may be due to a hampered process of metabolic adaptation in early lactating cows. In our opinion, adaptation to the negative energy balance is a gradual process. Because

  3. Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

    Science.gov (United States)

    Swanson, David L; Thomas, Nathan E; Liknes, Eric T; Cooper, Sheldon J

    2012-01-01

    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 mechanistic

  4. 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

  5. Environmental effects on energy metabolism and 86Rb elimination rates of fishes

    International Nuclear Information System (INIS)

    Peters, E.L.

    1994-01-01

    Relationships between energy metabolism and the turnover rates of number of important chemical and radiological elements (particularly the Group IA alkali metals: K, Rb, and Cs) have been observed in fishes. Using response surface statistics and fractional factorial ANOVA, the author examined the relative influences of temperature, salinity, food intake rate, mass, and their first order interactions on routine energy metabolism and 86 Rb elimination rates. Routine metabolic rates were increased primarily by increased temperature and salinity, with a strong body mass effect and a significant effect of food intake. 86 Rb elimination rates were increased primarily by increased temperature and salinity. There were no interactive effects between mass and either temperature or salinity for either routine energy metabolism or 86 Rb elimination rates. There was a significant interaction effect between temperature and salinity on routine energy metabolism rates, but not on 86 Rb elimination. The authors also observed a relationship between routine energy metabolism and 86 Rb elimination rates that may possibly be exploited as a means of estimating energy metabolic rates of fishes in the field. The statistical techniques used in this experiment have broad potential applications in assessing the contributions of combinations of environmental variables on contaminant kinetics, as well as in multiple toxicity testing, in that they greatly simplify experimental designs compared with traditional full-factorial methods

  6. Measurement of leach rates: a review

    International Nuclear Information System (INIS)

    Mendel, J.E.

    1982-01-01

    A historical perspective of the techniques that can be used to measure the leach rate of radioactive waste forms is presented. The achievement of leach rates that are as low as possible has been an important goal ever since the development of solidification processes for liquid radioactive wastes began in the 1950's. Leach tests can be divided into two major categories, dynamic and static, based on whether or not the leachant in contact with the test specimen is changed during the course of the test. Both types of tests have been used extensively. The results of leach tests can be used to compare waste forms, and that has been a major purpose of leach data heretofore; increasingly, however, the data now are needed for predicting long-term leaching behavior during geologic disposal. This requirement is introducing new complexities into leach testing methodology. 3 figures, 2 tables

  7. Flow rate measurement in a volume

    Energy Technology Data Exchange (ETDEWEB)

    Galvez, Cristhian

    2018-04-17

    A system for measuring flow rate within a volume includes one or more transmission devices that transmit one or more signals through fluid contained within the volume. The volume may be bounded, at least in part, by an outer structure and by an object at least partially contained within the outer structure. A transmission device located at a first location of the outer structure transmits a first signal to a second location of the outer structure. A second signal is transmitted through the fluid from the second location to a third location of the outer structure. The flow rate of the fluid within the volume may be determined based, at least in part, on the time of flight of both the first signal and the second signal.

  8. 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.

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

    Science.gov (United States)

    Starostová, Zuzana; Konarzewski, Marek; Kozłowski, Jan; Kratochvíl, Lukáš

    2013-01-01

    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.

  10. 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.

  11. Metabolic cold adaptation of polar fish based on measurements of aerobic oxygen consumption: fact or artefact? Artefact!

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2002-01-01

    Whether metabolic cold adaptation in polar fish, based on measurements of aerobic standard metabolic rate, is a fact or an artefact has been a dispute since Holeton asked the question in 1974. So far polar fish had been considered to be metabolically cold adapted because they were reported to have...... a considerably elevated resting oxygen consumption, or standard metabolic rate, compared with oxygen consumption values of tropical or temperate fish extrapolated to similar low polar temperatures. Recent experiments on arctic and Antarctic fish, however, do not show elevated resting aerobic oxygen consumption...

  12. Fasting respiratory exchange ratio and resting metabolic rate as predictors of weight gain : the Baltimore Longitudinal Study on Aging

    NARCIS (Netherlands)

    Seidell, J C; Muller, D C; Sorkin, J D; Andres, R.

    The authors followed 775 men (aged 18-98 years) participating in the Baltimore Longitudinal Study in Aging for an average of ten years. Resting metabolic rate and fasting respiratory exchange ratio (RER) were measured by indirect calorimetry on their first visit and related to subsequent weight

  13. 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.

  14. Association of Objectively Measured Physical Activity and Metabolic Syndrome Among US Adults With Osteoarthritis.

    Science.gov (United States)

    Liu, Shao-Hsien; Waring, Molly E; Eaton, Charles B; Lapane, Kate L

    2015-10-01

    To investigate the association between objectively measured physical activity and metabolic syndrome among adults with osteoarthritis (OA). Using cross-sectional data from the 2003-2006 National Health and Nutrition Examination Survey, we identified 566 adults with OA with available accelerometer data assessed using Actigraph AM-7164 and measurements necessary to determine metabolic syndrome by the Adult Treatment Panel III. Analysis of variance was conducted to examine the association between continuous variables in each activity level and metabolic syndrome components. Logistic models estimated the relationship of quartile of daily minutes of different physical activity levels to odds of metabolic syndrome adjusted for socioeconomic and health factors. Among persons with OA, most were women average age of 62.1 years and average disease duration of 12.9 years. Half of adults with OA had metabolic syndrome (51.0%; 95% confidence interval [95% CI] 44.2%-57.8%), and only 9.6% engaged in the recommended 150 minutes per week of moderate/vigorous physical activity. Total sedentary time was associated with higher rates of metabolic syndrome and its components, while light and objectively measured moderate/vigorous physical activity was inversely associated with metabolic syndrome and its components. Higher levels of light activity were associated with lower prevalence of metabolic syndrome (quartile 4 versus quartile 1: adjusted odds ratio 0.45, 95% CI 0.24-0.84, P for linear trend physical activity, especially in light intensity, is more likely to be associated with decreasing prevalence of metabolic syndrome among persons with OA. © 2015, American College of Rheumatology.

  15. Changes in Body Compositions and Basal Metabolic Rates during Treatment of Graves’ Disease

    Directory of Open Access Journals (Sweden)

    Min Joo Kim

    2018-01-01

    Full Text Available Objectives. Because thyroid hormone is an important determinant of body weight and basal metabolic rate, we investigated the changes in the basal metabolic rate and body composition sequentially after treatment for Graves’ disease. Methods. A prospective cohort study was performed with six women newly diagnosed with Graves’ disease. During a 52-week treatment of methimazole, body composition, resting respiratory expenditure (REE, and handgrip strength were measured consecutively. Results. After methimazole treatment, body weight was initially increased (0–8 weeks, subsequently plateaued (8–24 weeks, and gradually decreased in the later period (24–52 weeks despite the decreased food intake. The measured REE was 40% higher than the predicted REE at baseline, and it gradually decreased after treatment. REE positively correlated with thyroid hormone levels, peripheral deiodinase activity, and thyroid’s secretory capacity. Body compositional analyses showed that the fat mass increased during an earlier period (4–12 weeks, while the lean mass increased significantly during the later period (26–52 weeks. Consistent with the lean mass changes, muscle strength also significantly increased during the later period. Conclusions. Treatment of Graves’ disease increased body weight and fat mass transiently with decreased REE. However, long-term compositional changes moved in a beneficial direction increasing lean mass and reinforcing muscle strength, following decreasing fat percentages.

  16. a metabolic wastage model for the rate-yield trade off

    Indian Academy of Sciences (India)

    A METABOLIC WASTAGE MODEL FOR THE RATE-YIELD TRADE OFF. There is a growth limiting step in which an intermediate metabolite (m) has to hit a target molecule (t). ... D= rate of diffusing out. S= the rate of formation of the metabolite. The equilibrium loss decides the yield. The no. of activated targets decide the rate ...

  17. 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...... environment was held constant at a temperature corresponding to PMV=0 at sedentary activity. Even low activity changes of short duration (1 min at 20% relative work load) affected thermal perceptions. However, after circa 15 min of constant activity, subjective thermal responses approximated the steady...

  18. Evolutionary Rate Heterogeneity of Primary and Secondary Metabolic Pathway Genes in Arabidopsis thaliana.

    Science.gov (United States)

    Mukherjee, Dola; Mukherjee, Ashutosh; Ghosh, Tapash Chandra

    2015-11-10

    Primary metabolism is essential to plants for growth and development, and secondary metabolism helps plants to interact with the environment. Many plant metabolites are industrially important. These metabolites are produced by plants through complex metabolic pathways. Lack of knowledge about these pathways is hindering the successful breeding practices for these metabolites. For a better knowledge of the metabolism in plants as a whole, evolutionary rate variation of primary and secondary metabolic pathway genes is a prerequisite. In this study, evolutionary rate variation of primary and secondary metabolic pathway genes has been analyzed in the model plant Arabidopsis thaliana. Primary metabolic pathway genes were found to be more conserved than secondary metabolic pathway genes. Several factors such as gene structure, expression level, tissue specificity, multifunctionality, and domain number are the key factors behind this evolutionary rate variation. This study will help to better understand the evolutionary dynamics of plant metabolism. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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

    Science.gov (United States)

    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 cons...

  20. Seasonal field metabolic rates of American martens in Wisconsin

    Science.gov (United States)

    Jonathan H. Gilbert; Patrick A Zollner; Adam K. Green; John L. Wright

    2009-01-01

    We report on FMR of free-living American martens (Martes americana) in autumn and winter in northern Wisconsin. Mean body mass was significantly higher in males (1099 ± 43 [S.E.] g) than females (737 ± 28 g), with no significant difference by season. Daily mass change rates of martens did not differ from zero, and mass change rate...

  1. Hemispherical dominance of glucose metabolic rate in the brain of the 'normal' ageing population

    International Nuclear Information System (INIS)

    Cutts, D.A.; Spyrou, N.M.

    2004-01-01

    In the 'normal' ageing brain a decrease in the cerebral metabolic rate has been determined across many brain regions. It is determined whether age differences would affect metabolic rates in regions and different hemispheres of the brain. The regional metabolic rate of glucose (rCMRGlu) was examined in a group of 72 subjects, ages 22 to 82 years, with 36 regions of interest chosen from both hemispheres of the cortex, midbrain and cerebellum. To determine metabolic rates the in-vivo technique of positron emission tomography (PET) was employed. Three age groups were chosen to compare hemispherical differences. In both young and intermediate age groups the left hemisphere had higher rCMRGlu values than those of the right for the majority of regions with, although less pronounced in the intermediate group. Importantly, the older age group displayed little difference between hemispheres. (author)

  2. Temperature dependences of growth rates and carrying capacities of marine bacteria depart from metabolic theoretical predictions

    KAUST Repository

    Huete-Stauffer, Tamara Megan; Arandia-Gorostidi, Nestor; Dí az-Pé rez, Laura; Moran, Xose Anxelu G.

    2015-01-01

    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

  3. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R. [University of Massachusetts, Amherst

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  4. 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

  5. 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%; pdemands 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-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

  6. Dose rate measuring device and dose rate measuring method using the same

    International Nuclear Information System (INIS)

    Urata, Megumu; Matsushita, Takashi; Hanazawa, Sadao; Konno, Takahiro; Chiba, Yoshinori; Yumitate, Tadahiro

    1998-01-01

    The device of the present invention comprises a scintillation fiber scope having a shape elongated in the direction of the height of a pressure vessel and emitting light by incident of radiation to detect radiation, a radioactivity measuring device for measuring a dose rate based on the detection of the fiber scope and a reel means for dispensing and taking up the fiber scope, and it constituted such that the dose rate of the pressure vessel and that of a shroud are determined independently. Then, when the taken out shroud is contained in an container, excessive shielding is not necessary, in addition, this device can reliably be inserted to or withdrawn from complicated places between the pressure vessel and the shroud, and further, the dose rate of the pressure vessel and that of the shroud can be measured approximately accurately even when the thickness of them is different greatly. (N.H.)

  7. Dose rate measuring device and dose rate measuring method using the same

    Energy Technology Data Exchange (ETDEWEB)

    Urata, Megumu; Matsushita, Takashi; Hanazawa, Sadao; Konno, Takahiro; Chiba, Yoshinori; Yumitate, Tadahiro

    1998-11-13

    The device of the present invention comprises a scintillation fiber scope having a shape elongated in the direction of the height of a pressure vessel and emitting light by incident of radiation to detect radiation, a radioactivity measuring device for measuring a dose rate based on the detection of the fiber scope and a reel means for dispensing and taking up the fiber scope, and it constituted such that the dose rate of the pressure vessel and that of a shroud are determined independently. Then, when the taken out shroud is contained in an container, excessive shielding is not necessary, in addition, this device can reliably be inserted to or withdrawn from complicated places between the pressure vessel and the shroud, and further, the dose rate of the pressure vessel and that of the shroud can be measured approximately accurately even when the thickness of them is different greatly. (N.H.)

  8. 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...... 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.......05). Furthermore, the plasma concentrations of IgM and IgG and the mRNA expression of NF-kB and TNF-α were not affected (both; P>0.05), indicating the absence of inflammatory modulation by CuNano. These preliminary results demonstrated that CuNano, regardless of the day of injection, altered the metabolic rate...

  9. 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.

  10. Metabolic enzyme cost explains variable trade-offs between microbial growth rate and yield.

    Directory of Open Access Journals (Sweden)

    Meike T Wortel

    2018-02-01

    Full Text Available Microbes may maximize the number of daughter cells per time or per amount of nutrients consumed. These two strategies correspond, respectively, to the use of enzyme-efficient or substrate-efficient metabolic pathways. In reality, fast growth is often associated with wasteful, yield-inefficient metabolism, and a general thermodynamic trade-off between growth rate and biomass yield has been proposed to explain this. We studied growth rate/yield trade-offs by using a novel modeling framework, Enzyme-Flux Cost Minimization (EFCM and by assuming that the growth rate depends directly on the enzyme investment per rate of biomass production. In a comprehensive mathematical model of core metabolism in E. coli, we screened all elementary flux modes leading to cell synthesis, characterized them by the growth rates and yields they provide, and studied the shape of the resulting rate/yield Pareto front. By varying the model parameters, we found that the rate/yield trade-off is not universal, but depends on metabolic kinetics and environmental conditions. A prominent trade-off emerges under oxygen-limited growth, where yield-inefficient pathways support a 2-to-3 times higher growth rate than yield-efficient pathways. EFCM can be widely used to predict optimal metabolic states and growth rates under varying nutrient levels, perturbations of enzyme parameters, and single or multiple gene knockouts.

  11. Body Temperature Measurements for Metabolic Phenotyping in Mice

    Science.gov (United States)

    Meyer, Carola W.; Ootsuka, Youichirou; Romanovsky, Andrej A.

    2017-01-01

    Endothermic organisms rely on tightly balanced energy budgets to maintain a regulated body temperature and body mass. Metabolic phenotyping of mice, therefore, often includes the recording of body temperature. Thermometry in mice is conducted at various sites, using various devices and measurement practices, ranging from single-time probing to continuous temperature imaging. Whilst there is broad agreement that body temperature data is of value, procedural considerations of body temperature measurements in the context of metabolic phenotyping are missing. Here, we provide an overview of the various methods currently available for gathering body temperature data from mice. We explore the scope and limitations of thermometry in mice, with the hope of assisting researchers in the selection of appropriate approaches, and conditions, for comprehensive mouse phenotypic analyses. PMID:28824441

  12. 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.

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

    OpenAIRE

    MALISZEWSKA, Justyna; TĘGOWSKA, Eugenia

    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...

  14. Effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness of female patients with metabolic syndrome.

    Science.gov (United States)

    Kang, Seol-Jung; Kim, Eon-Ho; Ko, Kwang-Jun

    2016-06-01

    [Purpose] The purpose of this study was to investigate the effects of aerobic exercise on the resting heart rate, physical fitness, and arterial stiffness or female patients with metabolic syndrome. [Subjects and Methods] Subjects were randomly assigned to an exercise group (n=12) or a control group (n=11). Subjects in the exercise group performed aerobic exercise at 60-80% of maximum heart rate for 40 min 5 times a week for 12 weeks. The changes in metabolic syndrome risk factors, resting heart rate, physical fitness, and arterial stiffness were measured and analyzed before and after initiation of the exercise program to determine the effect of exercise. Arterial stiffness was assessed based on brachial-ankle pulse wave velocity (ba-PWV). [Results] Compared to the control group; The metabolic syndrome risk factors (weight, % body fat, waist circumference, systolic blood pressure, diastolic blood pressure, and HDL-Cholesterol) were significantly improved in the exercise: resting heart rate was significantly decreased; VO2max, muscle strength and muscle endurance were significantly increased; and ba-PWV was significantly decreased. [Conclusion] Aerobic exercise had beneficial effects on the resting heart rate, physical fitness, and arterial stiffness of patients with metabolic syndrome.

  15. Measuring the costs of exchange rate volatility

    OpenAIRE

    Paul R. Bergin

    2004-01-01

    Many countries go to great lengths to manage their exchange rates. Probably the most prominent recent example is the European Monetary Union, where all the members abandoned their national currencies and adopted the euro. A number of developing countries maintain other kinds of regimes of managed exchange rates, even though they face potent market pressures to let their exchange rates float. One of the main motives for these arrangements stems from the extreme volatility of exchange rates. Th...

  16. Measuring Implicit Rental Rates for Farm Capital

    OpenAIRE

    Hrubovcak, James

    1986-01-01

    Developing implicit rental rates for capital inputs is an Important step in understanding the Impact of tax law changes on agricultural investments This article develops a methodology for estimating implicit rental rates and presents annual estimates of rental rates for seven categories of farm equipment and structures from 1955 to 1979 This article also compares these rental rates With those estimated under a no-tax alternative The author developed a method for estimating marginal Federal In...

  17. Visual rating of medial temporal lobe metabolism in mild cognitive impairment and Alzheimer's disease using FDG-PET

    International Nuclear Information System (INIS)

    Mosconi, Lisa; Santi, Susan De; Li, Yi; Li, Juan; Zhan, Jiong; Boppana, Madhu; Tsui, Wai Hon; Leon, Mony J. de; Pupi, Alberto

    2006-01-01

    This study was designed to examine the utility of visual inspection of medial temporal lobe (MTL) metabolism in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD) using FDG-PET scans. Seventy-five subjects [27 normal controls (NL), 26 MCI, and 22 AD] with FDG-PET and MRI scans were included in this study. We developed a four-point visual rating scale to evaluate the presence and severity of MTL hypometabolism on FDG-PET scans. The visual MTL ratings were compared with quantitative glucose metabolic rate (MR glc ) data extracted using regions of interest (ROIs) from the MRI-coregistered PET scans of all subjects. A standard rating evaluation of neocortical hypometabolism was also completed. Logistic regressions were used to determine and compare the diagnostic accuracy of the MTL and cortical ratings. For both MTL and cortical ratings, high intra- and inter-rater reliabilities were found (p values glc measures (p values <0.001). The combination of MTL and cortical ratings significantly improved the diagnostic accuracy over the cortical rating alone, with 100% of AD, 77% of MCI, and 85% of NL cases being correctly identified. This study shows that the visual rating of MTL hypometabolism on PET is reliable, yields a diagnostic accuracy equal to the quantitative ROI measures, and is clinically useful and more sensitive than cortical ratings for patients with MCI. We suggest this method be further evaluated for its potential in the early diagnosis of AD. (orig.)

  18. 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...

  19. Metabolic rate and body temperature of an African sun bird ...

    African Journals Online (AJOL)

    The oxygen consumption (VO2) of the lesser double-collared sunbird, Nectarinia chalybea, was measured at ambient temperatures (Ta) from 7 to 35°C. The diel variation in body temperature (Tb) and wet thermal conductance (C) was also determined. The sunbirds (mean mass 8.36 g ± S.E. 0.21 g) showed a pronounced ...

  20. Changes in Microbial Energy Metabolism Measured by Nanocalorimetry during Growth Phase Transitions

    Science.gov (United States)

    Robador, Alberto; LaRowe, Douglas E.; Finkel, Steven E.; Amend, Jan P.; Nealson, Kenneth H.

    2018-01-01

    Calorimetric measurements of the change in heat due to microbial metabolic activity convey information about the kinetics, as well as the thermodynamics, of all chemical reactions taking place in a cell. Calorimetric measurements of heat production made on bacterial cultures have recorded the energy yields of all co-occurring microbial metabolic reactions, but this is a complex, composite signal that is difficult to interpret. Here we show that nanocalorimetry can be used in combination with enumeration of viable cell counts, oxygen consumption rates, cellular protein content, and thermodynamic calculations to assess catabolic rates of an isolate of Shewanella oneidensis MR-1 and infer what fraction of the chemical energy is assimilated by the culture into biomass and what fraction is dissipated in the form of heat under different limiting conditions. In particular, our results demonstrate that catabolic rates are not necessarily coupled to rates of cell division, but rather, to physiological rearrangements of S. oneidensis MR-1 upon growth phase transitions. In addition, we conclude that the heat released by growing microorganisms can be measured in order to understand the physiochemical nature of the energy transformation and dissipation associated with microbial metabolic activity in conditions approaching those found in natural systems. PMID:29449836

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

    International Nuclear Information System (INIS)

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

    1987-01-01

    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. (author)

  2. The metabolic clearance rate of corticosterone in lean and obese male Zucker rats

    International Nuclear Information System (INIS)

    White, B.D.; Corll, C.B.; Porter, J.R.

    1989-01-01

    The obese Zucker rat is an animal model of human juvenile-onset obesity. These rats exhibit numerous endocrine and metabolic abnormalities. Adrenalectomy of obese rats has been shown to reduce or reverse several of these abnormalities, thereby implying that corticosterone may contribute to the expression of obesity in this animal. Furthermore, it has been shown that the circadian rhythm of plasma corticosterone is disturbed in obese Zucker rats resulting in elevated morning plasma corticosterone concentrations in obese rats as compared to lean rats. In a effort to better elucidate the mechanism of the elevated morning levels of plasma corticosterone, the metabolic clearance rate of corticosterone was determined in the morning for lean and obese male Zucker rats (12 to 20 weeks). Additionally, the biliary and urinary excretion of labeled corticosterone and/or its metabolites were determined. The metabolic clearance rate of corticosterone was significantly greater in obese rats than in their lean counterparts. Both the metabolic clearance rate and the volume of compartments significantly correlated with body weight. No correlation was found between body weight and the elimination rate constant. The increased metabolic clearance rate of obese rats appeared to be due to an increase in the physiologic distribution of corticosterone and not to an alteration in the enzymes responsible for corticosterone metabolism. It appears that the metabolic clearance rate of corticosterone in obese Zucker rats does not contribute to elevated morning concentrations of plasma corticosterone previously observed in these animals. It suggests that the adrenal corticosterone secretion rate must actually be greater than one would expect from the plasma corticosterone concentrations alone

  3. Measuring heart rate with optical sensor

    NARCIS (Netherlands)

    Barachi, M. (Mitra)

    2014-01-01

    The problem addressed in this report is to verify the possibility of using an optical sensor in the SaxShirt in order to extract the heart rate. There are specifically three questions that we try to address. 1) How is it possible to extract heart rate (BPM) from the optical sensor? 2) Is it

  4. Female fibromyalgia patients: lower resting metabolic rates than matched healthy controls.

    Science.gov (United States)

    Lowe, John C; Yellin, Jackie; Honeyman-Lowe, Gina

    2006-07-01

    Many features of fibromyalgia and hypothyroidism are virtually the same, and thyroid hormone treatment trials have reduced or eliminated fibromyalgia symptoms. These findings led the authors to test the hypothesis that fibromyalgia patients are hypometabolic compared to matched controls. Resting metabolic rate (RMR) was measured by indirect calorimetry and body composition by bioelectrical impedance for 15 fibromyalgia patients and 15 healthy matched controls. Measured resting metabolic rate (mRMR) was compared to percentages of predicted RMR (pRMR) by fat-free weight (FFW) (Sterling-Passmore: SP) and by sex, age, height, and weight (Harris-Benedict: HB). Patients had a lower mRMR (4,306.31+/-1077.66 kJ vs 5,411.59+/-695.95 kJ, p=0.0028) and lower percentages of pRMRs (SP: -28.42+/-15.82% vs -6.83+/-12.55%, pBMI) best accounted for variability in controls' RMRs, age and fat weight (FW) did for patients. In the patient group, TSH level accounted for 28% of the variance in pain distribution, and free T3 (FT3) accounted for 30% of the variance in pressure-pain threshold. Patients had lower mRMR and percentages of pRMRs. The lower RMRs were not due to calorie restriction or low FFW. Patients' normal FFW argues against low physical activity as the mechanism. TSH, FT4, and FT3 levels did not correlate with RMRs in either group. This does not rule out inadequate thyroid hormone regulation because studies show these laboratory values do not reliably predict RMR.

  5. 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.

  6. Basal metabolic rate and the mass of tissues differing in metabolic scope : Migration-related covariation between individual knots Calidris canutus

    NARCIS (Netherlands)

    Weber, TP; Piersma, T; Weber, Thomas P.

    To examine whether variability in the basal metabolic rate (BMR) of migrant shorebirds is a function of a variably sized metabolic machinery or of temporal changes in metabolic intensities at the tissue level, BMR, body composition and activity of cytochrome-c oxidase (CCO, a marker for maximum

  7. 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.

  8. 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.

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

    Science.gov (United States)

    Caballero, Isabel C; Sakla, Andrew J; Detwiler, Jillian T; Le Gall, Marion; Behmer, Spencer T; Criscione, Charles D

    2015-01-01

    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.

  10. Oxygen consumption rate v. rate of energy utilization of fishes: a comparison and brief history of the two measurements.

    Science.gov (United States)

    Nelson, J A

    2016-01-01

    Accounting for energy use by fishes has been taking place for over 200 years. The original, and continuing gold standard for measuring energy use in terrestrial animals, is to account for the waste heat produced by all reactions of metabolism, a process referred to as direct calorimetry. Direct calorimetry is not easy or convenient in terrestrial animals and is extremely difficult in aquatic animals. Thus, the original and most subsequent measurements of metabolic activity in fishes have been measured via indirect calorimetry. Indirect calorimetry takes advantage of the fact that oxygen is consumed and carbon dioxide is produced during the catabolic conversion of foodstuffs or energy reserves to useful ATP energy. As measuring [CO2 ] in water is more challenging than measuring [O2 ], most indirect calorimetric studies on fishes have used the rate of O2 consumption. To relate measurements of O2 consumption back to actual energy usage requires knowledge of the substrate being oxidized. Many contemporary studies of O2 consumption by fishes do not attempt to relate this measurement back to actual energy usage. Thus, the rate of oxygen consumption (M˙O2 ) has become a measurement in its own right that is not necessarily synonymous with metabolic rate. Because all extant fishes are obligate aerobes (many fishes engage in substantial net anaerobiosis, but all require oxygen to complete their life cycle), this discrepancy does not appear to be of great concern to the fish biology community, and reports of fish oxygen consumption, without being related to energy, have proliferated. Unfortunately, under some circumstances, these measures can be quite different from one another. A review of the methodological history of the two measurements and a look towards the future are included. © 2016 The Fisheries Society of the British Isles.

  11. Effects of pre- and postnatal polychlorinated biphenyl exposure on metabolic rate and thyroid hormones of white-footed mice

    Science.gov (United States)

    French, J.B.; Voltura, M.B.; Tomasi, T.E.

    2001-01-01

    Energy budgets have proven to be a valuable tool for predicting life history from physiological data in terrestrial vertebrates, yet these concepts have not been applied to the physiological effects of contaminants. Contaminants might affect energy budgets by imposing an additional metabolic cost or by reducing the overall amount of energy taken in; either process will reduce the energy available for production (i.e., growth or reproduction). This study examined whole animal energetic effects of polychlorinated biphenyl (PCB) exposure in white-footed mice (Peromyscus leucopus). Exposure to PCBs is known to reduce concentrations of plasma thyroid hormones, and thyroid hormones exert strong control over the rate of energy metabolism in mammals. Peromyscus leucopus that were proven breeders were fed PCBs in their food at 0, 10, and 25 ppm. Through lactation, offspring were exposed to PCB from conception and were maintained on the maternal diet to adulthood. No effects were seen on energy metabolism (O-2 consumption, measured in adulthood) or on growth, but there were large dose-dependent decreases in thyroid hormone concentrations, particularly T-4. The apparent disparity in our data between unchanged metabolic rates and 50% reductions in T-4 concentrations can be rationalized by noting that free T-3 (the fraction not bound to plasma protein) in treated mice was not significantly different from controls and that metabolism is most strongly influenced by free T-3. Overall, this study did not demonstrate any energetic consequences of PCB exposure in P. leucopus at dietary concentrations up to 25 ppm.

  12. 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

  13. Effects of vasoactive and metabolic active substances (measurement of RCBF)

    Energy Technology Data Exchange (ETDEWEB)

    Herrschaft, H.

    1986-09-29

    Methods, principles, normal values, reproducibility and clinical indications of rCBF-measurements, using the intraartrial 133-Xenon-clearance-technique, are presented. The effect of vaso- and metabolically active drugs on cerebral blood flow was examined in 215 patients, suffering from cerebral ischemia. Significant increase of rCBF was ascertained after intravenous injection of centrophenoxine, pyrithioxine, extractum sanguis deproteinatus, piracetam and solutions of low molecular dextran. All the other drugs tested proved to be either without any effect or caused decrease of rCBF. In 130 patients with obstructive disease of internal carotid artery after surgery at an interval of 6 - 8 weeks and 1 year a significant increase of CBF could be stated. The rank of psychological tests and quantitative EEF-investigations relating to evidence of efficacy of metabolically active drugs is discussed critically. Therapeutic efficacy and clinical relevance of vaso- and metabolically active drugs in cerebral ischemia of man are to be substantiated only by double-blind controlled studies.

  14. Effects of vasoactive and metabolic active substances (measurement of RCBF)

    International Nuclear Information System (INIS)

    Herrschaft, H.

    1986-01-01

    Methods, principles, normal values, reproducibility and clinical indications of rCBF-measurements, using the intraartrial 133-Xenon-clearance-technique, are presented. The effect of vaso- and metabolically active drugs on cerebral blood flow was examined in 215 patients, suffering from cerebral ischemia. Significant increase of rCBF was ascertained after intravenous injection of centrophenoxine, pyrithioxine, extractum sanguis deproteinatus, piracetam and solutions of low molecular dextran. All the other drugs tested proved to be either without any effect or caused decrease of rCBF. In 130 patients with obstructive disease of internal carotid artery after surgery at an interval of 6 - 8 weeks and 1 year a significant increase of CBF could be stated. The rank of psychological tests and quantitative EEF-investigations relating to evidence of efficacy of metabolically active drugs is discussed critically. Therapeutic efficacy and clinical relevance of vaso- and metabolically active drugs in cerebral ischemia of man are to be substantiated only by double-blind controlled studies. (orig.) [de

  15. Measurements of Protein Crystal Face Growth Rates

    Science.gov (United States)

    Gorti, S.

    2014-01-01

    Protein crystal growth rates will be determined for several hyperthermophile proteins.; The growth rates will be assessed using available theoretical models, including kinetic roughening.; If/when kinetic roughening supersaturations are established, determinations of protein crystal quality over a range of supersaturations will also be assessed.; The results of our ground based effort may well address the existence of a correlation between fundamental growth mechanisms and protein crystal quality.

  16. Age differences in intercorrelations between regional cerebral metabolic rates for glucose

    International Nuclear Information System (INIS)

    Horwitz, B.; Duara, R.; Rapoport, S.I.

    1986-01-01

    Patterns of cerebral metabolic intercorrelations were compared in the resting state in 15 healthy young men (ages 20 to 32 years) and 15 healthy elderly men (ages 64 to 83 years). Controlling for whole-brain glucose metabolism, partial correlation coefficients were determined between pairs of regional cerebral metabolic rates for glucose determined by positron emission tomography using [18F]fluorodeoxyglucose and obtained in 59 brain regions. Compared with the young men, the elderly men had fewer statistically significant correlations, with the most notable reductions observed between the parietal lobe regions, and between the parietal and frontal lobe regions. These results suggest that cerebral functional interactions are reduced in healthy elderly men

  17. Standard metabolic rates of early life stages of the diamondback terrapin (Malaclemys terrapin), an estuarine turtle, suggest correlates between life history changes and the metabolic economy of hatchlings.

    Science.gov (United States)

    Rowe, Christopher L

    2018-04-01

    I estimated standard metabolic rates (SMR) using measurements of oxygen consumption rates of embryos and unfed, resting hatchlings of the diamondback terrapin (Malaclemys terrapin) three times during embryonic development and twice during the early post-hatching period. The highest observed SMRs occurred during mid to late embryonic development and the early post-hatching period when hatchlings were still reliant on yolk reserves provided by the mother. Hatchlings that were reliant on yolk displayed per capita SMR 135 % higher than when measured 25 calendar days later after they became reliant on exogenous resources. The magnitude of the difference in hatchling SMR between yolk-reliant and exogenously feeding stages was much greater than that attributed to costs of digestion (specific dynamic action) observed in another emydid turtle, suggesting that processing of the yolk was not solely responsible for the observed difference. The pre-feeding period of yolk reliance of hatchlings corresponds with the period of dispersal from the nesting site, suggesting that elevated SMR during this period could facilitate dispersal activities. Thus, I hypothesize that the reduction in SMR after the development of feeding behaviors may reflect an energy optimization strategy in which a high metabolic expenditure in support of development and growth of the embryo and dispersal of the hatchling is followed by a substantial reduction in metabolic expenditure coincident with the individual becoming reliant on exogenous resources following yolk depletion. Copyright © 2018 Elsevier GmbH. All rights reserved.

  18. 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.

  19. Evolution of mitochondrial DNA and its relation to basal metabolic rate.

    Science.gov (United States)

    Feng, Ping; Zhao, Huabin; Lu, Xin

    2015-08-01

    Energy metabolism is essential for the survival of animals, which can be characterized by maximum metabolic rate (MMR) and basal metabolic rate (BMR). Because of the crucial roles of mitochondria in energy metabolism, mitochondrial DNA (mtDNA) has been subjected to stronger purifying selection in strongly locomotive than weakly locomotive birds and mammals. Although maximum locomotive speed (an indicator of MMR) showed a negative correlation with the evolutionary rate of mtDNA, it is unclear whether BMR has driven the evolution of mtDNA. Here, we take advantage of the large amount of mtDNA and BMR data in 106 mammals to test whether BMR has influenced the mtDNA evolution. Our results showed that, in addition to the locomotive speed, mammals with higher BMR have subjected to stronger purifying selection on mtDNA than did those with lower BMR. The evolution of mammalian mtDNA has been modified by two levels of energy metabolism, including MMR and BMR. Our study provides a more comprehensive view of mtDNA evolution in relation to energy metabolism.

  20. Special K: testing the potassium link between radioactive rubidium (86Rb) turnover and metabolic rate.

    Science.gov (United States)

    Tomlinson, Sean; Mathialagan, Priya D; Maloney, Shane K

    2014-04-01

    The measurement of (86)Rb turnover recently has been suggested as a useful method for measuring field metabolic rate in small animals. We investigated a proposed mechanism of (86)Rb turnover, its analogy to K(+), by comparing the turnover of (86)Rb in a model insect, the rhinoceros beetle Xylotrupes gideon, fed a diet of plum jam or plum jam enriched with K(+) or Rb(+). The turnover of (86)Rb in the beetles on the K(+) and the Rb(+) diets was higher than that for beetles on the jam diet (F2,311=32.4; P=1.58×10(-13)). We also exposed the beetles to different ambient temperatures to induce differences in metabolic rate ( ) while feeding them the jam and K(+) diets. was higher at higher ambient temperature (Ta) for both jam (F1,11=14.56; P=0.003) and K(+) (F1,8=15.39; P=0.004) dietary groups, and the turnover of (86)Rb was higher at higher Ta for both jam (F1,11=10.80; P=0.007) and K(+) (F1,8=12.34; P=0.008) dietary groups. There was a significant relationship between (86)Rb turnover and for both the jam (F1,11=35.00; P=1.0×10(-3)) and the K(+) (F1,8=64.33; P=4.3×10(-5)) diets, but the relationship differed between the diets (F1,19=14.07; P=0.001), with a higher (86)Rb turnover in beetles on the K(+)-enriched than on the jam diet at all Ta. We conclude that (86)Rb turnover is related to K(+) metabolism, and that this is the mechanism of the relationship between (86)Rb turnover and . Studies relating (86)Rb turnover to should maintain dietary [K] as close as possible to that of natural diets for the most accurate calibrations for free-ranging animals.

  1. Measuring Change with the Rating Scale Model.

    Science.gov (United States)

    Ludlow, Larry H.; And Others

    The Rehabilitation Research and Development Laboratory at the United States Veterans Administration Hines Hospital is engaged in a long-term evaluation of blind rehabilitation. One aspect of the evaluation project focuses on the measurement of attitudes toward blindness. Our aim is to measure changes in attitudes toward blindness from…

  2. Local cerebral metabolic rate of glucose (lCMRGlc) in treated and untreated patients with Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Rougemont, D; Baron, J C; Collard, P; Bustany, P; Comar, D; Agid, Y

    1983-06-01

    Local cerebral metabolic rate of glucose (lCMRGlc) was measured twice, using positron emission tomography and /sup 18/F-Fluoro-2-deoxy-D-glucose (/sup 18/FDG), in 4 patients with Parkinson disease, first unmedicated and then treated with L-DOPA. Despite a dramatic clinical improvement, no significant changes in lCMRGlc could be detected. Moreover, no reproducible differences of lCMRGlc were found between patients with Parkinson disease and with normal brain.

  3. Local cerebral metabolic rate of glucose (lCMRGlc) in treated and untreated patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Rougemont, D.; Baron, J.C.; Collard, P.; Bustany, P.; Comar, D.; Agid, Y.

    1983-06-01

    Local cerebral metabolic rate of glucose (lCMRGlc) was measured twice, using positron emission tomography and 18 F-Fluoro-2-deoxy-D-glucose ( 18 FDG), in 4 patients with Parkinson disease, first unmedicated and then treated with L-DOPA. Despite a dramatic clinical improvement, no significant changes in lCMRGlc could be detected. Moreover, no reproducible differences of lCMRGlc were found between patients with Parkinson disease and with normal brain

  4. Basal metabolic rate can evolve independently of morphological and behavioural traits.

    Science.gov (United States)

    Mathot, K J; Martin, K; Kempenaers, B; Forstmeier, W

    2013-09-01

    Quantitative genetic analyses of basal metabolic rate (BMR) can inform us about the evolvability of the trait by providing estimates of heritability, and also of genetic correlations with other traits that may constrain the ability of BMR to respond to selection. Here, we studied a captive population of zebra finches (Taeniopygia guttata) in which selection lines for male courtship rate have been established. We measure BMR in these lines to see whether selection on male sexual activity would change BMR as a potentially correlated trait. We find that the genetic correlation between courtship rate and BMR is practically zero, indicating that the two traits can evolve independently of each other. Interestingly, we find that the heritability of BMR in our population (h(2)=0.45) is markedly higher than was previously reported for a captive zebra finch population from Norway. A comparison of the two studies shows that additive genetic variance in BMR has been largely depleted in the Norwegian population, especially the genetic variance in BMR that is independent of body mass. In our population, the slope of BMR increase with body mass differs not only between the sexes but also between the six selection lines, which we tentatively attribute to genetic drift and/or founder effects being strong in small populations. Our study therefore highlights two things. First, the evolvability of BMR may be less constrained by genetic correlations and lack of independent genetic variation than previously described. Second, genetic drift in small populations can rapidly lead to different evolvabilities across populations.

  5. Basal metabolic rate is positively correlated with parental investment in laboratory mice

    Science.gov (United States)

    Sadowska, Julita; Gębczyński, Andrzej K.; Konarzewski, Marek

    2013-01-01

    The assimilation capacity (AC) hypothesis for the evolution of endothermy predicts that the maternal basal metabolic rate (BMR) should be positively correlated with the capacity for parental investment. In this study, we provide a unique test of the AC model based on mice from a long-term selection experiment designed to produce divergent levels of BMR. By constructing experimental families with cross-fostered litters, we were able to control for the effect of the mother as well as the type of pup based on the selected lines. We found that mothers with genetically determined high levels of BMR were characterized by higher parental investment capacity, measured as the offspring growth rate. We also found higher food consumption and heavier visceral organs in the females with high BMR. These findings suggested that the high-BMR females have higher energy acquisition abilities. When the effect of the line type of a foster mother was controlled, the pup line type significantly affected the growth rate only in the first week of life, with young from the high-BMR line type growing more rapidly. Our results support the predictions of the AC model. PMID:23282996

  6. White-nose syndrome increases torpid metabolic rate and evaporative water loss in hibernating bats.

    Science.gov (United States)

    McGuire, Liam P; Mayberry, Heather W; Willis, Craig K R

    2017-12-01

    Fungal diseases of wildlife typically manifest as superficial skin infections but can have devastating consequences for host physiology and survival. White-nose syndrome (WNS) is a fungal skin disease that has killed millions of hibernating bats in North America since 2007. Infection with the fungus Pseudogymnoascus destructans causes bats to rewarm too often during hibernation, but the cause of increased arousal rates remains unknown. On the basis of data from studies of captive and free-living bats, two mechanistic models have been proposed to explain disease processes in WNS. Key predictions of both models are that WNS-affected bats will show 1 ) higher metabolic rates during torpor (TMR) and 2 ) higher rates of evaporative water loss (EWL). We collected bats from a WNS-negative hibernaculum, inoculated one group with P. destructans , and sham-inoculated a second group as controls. After 4 mo of hibernation, TMR and EWL were measured using respirometry. Both predictions were supported, and our data suggest that infected bats were more affected by variation in ambient humidity than controls. Furthermore, disease severity, as indicated by the area of the wing with UV fluorescence, was positively correlated with EWL, but not TMR. Our results provide the first direct evidence that heightened energy expenditure during torpor and higher EWL independently contribute to WNS pathophysiology, with implications for the design of potential treatments for the disease. Copyright © 2017 the American Physiological Society.

  7. A quantitative theory of solid tumor growth, metabolic rate and vascularization.

    Directory of Open Access Journals (Sweden)

    Alexander B Herman

    Full Text Available The relationships between cellular, structural and dynamical properties of tumors have traditionally been studied separately. Here, we construct a quantitative, predictive theory of solid tumor growth, metabolic rate, vascularization and necrosis that integrates the relationships between these properties. To accomplish this, we develop a comprehensive theory that describes the interface and integration of the tumor vascular network and resource supply with the cardiovascular system of the host. Our theory enables a quantitative understanding of how cells, tissues, and vascular networks act together across multiple scales by building on recent theoretical advances in modeling both healthy vasculature and the detailed processes of angiogenesis and tumor growth. The theory explicitly relates tumor vascularization and growth to metabolic rate, and yields extensive predictions for tumor properties, including growth rates, metabolic rates, degree of necrosis, blood flow rates and vessel sizes. Besides these quantitative predictions, we explain how growth rates depend on capillary density and metabolic rate, and why similar tumors grow slower and occur less frequently in larger animals, shedding light on Peto's paradox. Various implications for potential therapeutic strategies and further research are discussed.

  8. [Analysis of body composition and resting metabolic rate of 858 middle-aged and elderly people in urban area of Beijing].

    Science.gov (United States)

    Yu, D N; Xian, T Z; Wang, L J; Cheng, B; Sun, M X; Guo, L X

    2018-05-10

    Objective: To understand the overweight rate and obesity rate in middle-aged and elderly people in urban area of Beijing, and analyze the changes of body composition and resting metabolic rate with age. Methods: From November 2014 to December 2015, body composition measurement and resting metabolic rate detection were conducted among 858 people aged 51 to 99 years, including 760 men, 98 women, who received physical examination at Beijing Hospital. Results: The overweight rate was 51.4 % , and the obesity rate was 16.9 % . The overweight rate was 26.5 % and the obesity rate was 14.3 % in women, significantly lower than those in men (54.6 % and 17.2 % ) ( P area and resting metabolic rate in different age groups were different ( P area increased obviously ( P area increased significantly in age group 70- years ( P area of Beijing, and the rates were higher in men than in women. With the increase of age, the skeletal muscle volume, muscle index and resting metabolic rate gradually decreased, while the percentage of body fat and visceral fat area increased; Overweight and obese people had earlier changes in body composition and resting metabolic rate.

  9. Automated Speech Rate Measurement in Dysarthria

    Science.gov (United States)

    Martens, Heidi; Dekens, Tomas; Van Nuffelen, Gwen; Latacz, Lukas; Verhelst, Werner; De Bodt, Marc

    2015-01-01

    Purpose: In this study, a new algorithm for automated determination of speech rate (SR) in dysarthric speech is evaluated. We investigated how reliably the algorithm calculates the SR of dysarthric speech samples when compared with calculation performed by speech-language pathologists. Method: The new algorithm was trained and tested using Dutch…

  10. 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 diabetes mellitus. Metabolic syndrome was present in 18.5% of this group of Mexican individuals with type 1 diabetes

  11. 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

  12. Effects of antiseptic mouthwash on resting metabolic rate: A randomized, double-blind, crossover study.

    Science.gov (United States)

    Sundqvist, Michaela L; Lundberg, Jon O; Weitzberg, Eddie

    2016-12-30

    The nitrate-nitrite-nitric oxide pathway has emerged as a significant source of nitric oxide (NO) bioactivity. Dietary intake of inorganic nitrate has a number of cardiovascular effects as well as a decrease in oxygen cost during exercise and a reduction in resting metabolic rate (RMR). Oral bacteria have a key role in bioactivation of inorganic nitrate since they catalyse the conversion of salivary nitrate to the more reactive nitrite anion. Recent studies demonstrate that blood pressure increases with the use of an antiseptic mouthwash, indicating that endogenous, NO-synthase derived nitrate is recycled into nitrite and NO, sufficiently to modulate cardiovascular function. Here we tested if also RMR would be affected by an antiseptic mouthwash. Seventeen healthy normotensive female subjects (23 ± 4 y) participated in this randomized, double-blinded, crossover study. During two 3-day periods separated by 28 days the subjects consumed a diet low in nitrate combined with rinsing their mouth three times daily with a chlorhexidine-containing mouthwash (mouthwash) or placebo mouthwash (placebo) with similar taste but no antiseptic properties. Resting metabolic rate (RMR) was measured by indirect calorimetry and 24 h ambulatory blood pressure recordings were obtained after each intervention together with blood, saliva and urine samples. Treatment with chlorhexidine-containing mouthwash effectively reduced oral conversion of nitrate to nitrite but had no effect on plasma levels of these anions or plasma cGMP. RMR and 24 h ambulatory blood pressure were unaffected by the intervention. We conclude that in young healthy females an antiseptic mouthwash was effective in disrupting oral bacterial nitrate conversion to nitrite, but this was not associated with changes in plasma nitrite, RMR or blood pressure. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. 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.

  14. Blood flow rate measurements with indicator techniques revisited

    DEFF Research Database (Denmark)

    Sejrsen, Per; Bülow, Jens

    2009-01-01

    In view of the emerging role, disturbances in regional blood flow rate seem to play in the pathogenesis of the metabolic syndrome; we review the concepts of the classical indicator dilution and washout techniques used for determinations of regional blood flow rate. Prerequisites, assumptions......, necessary precautions for the application of these experimental techniques are emphasized. Special attention has been carried out to elucidate the consequence of a choice of indicators having a large distribution volume in the tissues....

  15. Effects of Contingency versus Constraints on the Body-Mass Scaling of Metabolic Rate

    Directory of Open Access Journals (Sweden)

    Douglas S. Glazier

    2018-01-01

    Full Text Available I illustrate the effects of both contingency and constraints on the body-mass scaling of metabolic rate by analyzing the significantly different influences of ambient temperature (Ta on metabolic scaling in ectothermic versus endothermic animals. Interspecific comparisons show that increasing Ta results in decreasing metabolic scaling slopes in ectotherms, but increasing slopes in endotherms, a pattern uniquely predicted by the metabolic-level boundaries hypothesis, as amended to include effects of the scaling of thermal conductance in endotherms outside their thermoneutral zone. No other published theoretical model explicitly predicts this striking variation in metabolic scaling, which I explain in terms of contingent effects of Ta and thermoregulatory strategy in the context of physical and geometric constraints related to the scaling of surface area, volume, and heat flow across surfaces. My analysis shows that theoretical models focused on an ideal 3/4-power law, as explained by a single universally applicable mechanism, are clearly inadequate for explaining the diversity and environmental sensitivity of metabolic scaling. An important challenge is to develop a theory of metabolic scaling that recognizes the contingent effects of multiple mechanisms that are modulated by several extrinsic and intrinsic factors within specified constraints.

  16. Quantitative rates of brain glucose metabolism distinguish minimally conscious from vegetative state patients.

    Science.gov (United States)

    Stender, Johan; Kupers, Ron; Rodell, Anders; Thibaut, Aurore; Chatelle, Camille; Bruno, Marie-Aurélie; Gejl, Michael; Bernard, Claire; Hustinx, Roland; Laureys, Steven; Gjedde, Albert

    2015-01-01

    The differentiation of the vegetative or unresponsive wakefulness syndrome (VS/UWS) from the minimally conscious state (MCS) is an important clinical issue. The cerebral metabolic rate of glucose (CMRglc) declines when consciousness is lost, and may reveal the residual cognitive function 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 these results reveal a significant correlation between whole-brain energy metabolism and level of consciousness, suggesting that quantitative values of CMRglc reveal consciousness in severely brain-injured patients.

  17. 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

  18. An explanation of the relationship between mass, metabolic rate and characteristic length for placental mammals

    Directory of Open Access Journals (Sweden)

    Charles C. Frasier

    2015-09-01

    Full Text Available 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(bodymassb. 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

  19. 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......The differentiation of the vegetative or unresponsive wakefulness syndrome (VS/UWS) from the minimally conscious state (MCS) is an important clinical issue. The cerebral metabolic rate of glucose (CMRglc) declines when consciousness is lost, and may reveal the residual cognitive function...... these results reveal a significant correlation between whole-brain energy metabolism and level of consciousness, suggesting that quantitative values of CMRglc reveal consciousness in severely brain-injured patients.Journal of Cerebral Blood Flow & Metabolism advance online publication, 8 October 2014; doi:10...

  20. Leak rate measurements and detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.; Shack, W.J.; Claytor, T.

    1983-10-01

    A research program is under way to evaluate and develop improve leak detection systems. The primary focus of the work has been on acoustic emission detection of leaks. Leaks from artificial flaws, laboratory-generated IGSCCs and thermal fatigue cracks, and field-induced intergranular stress corrosion cracks (IGSCCs) from reactor piping have been examined. The effects of pressure, temperature, and leak rate and geometry on the acoustic signature are under study. The use of cross-correlation techniques for leak location and pattern recognition and autocorrelation for source discrimination is also being considered

  1. Measuring Transpiration to Regulate Winter Irrigation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Samuelson, Lisa [Auburn University

    2006-11-08

    Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

  2. High Yolk Testosterone Transfer Is Associated with an Increased Female Metabolic Rate.

    Science.gov (United States)

    Tschirren, Barbara; Ziegler, Ann-Kathrin; Canale, Cindy I; Okuliarová, Monika; Zeman, Michal; Giraudeau, Mathieu

    2016-01-01

    Yolk androgens of maternal origin are important mediators of prenatal maternal effects. Although in many species short-term benefits of exposure to high yolk androgen concentrations for the offspring have been observed, females differ substantially in the amount of androgens they transfer to their eggs. It suggests that costs for the offspring or the mother constrain the evolution of maternal hormone transfer. However, to date, the nature of these costs remains poorly understood. Unlike most previous work that focused on potential costs for the offspring, we here investigated whether high yolk testosterone transfer is associated with metabolic costs (i.e., a higher metabolic rate) for the mother. We show that Japanese quail (Coturnix japonica) females that deposit higher testosterone concentrations into their eggs have a higher resting metabolic rate. Because a higher metabolic rate is often associated with a shorter life span, this relationship may explain the negative association between yolk testosterone transfer and female longevity observed in the wild. Our results suggest that metabolic costs for the mother can balance the short-term benefits of yolk testosterone exposure for the offspring, thereby contributing to the maintenance of variation in maternal yolk hormone transfer in natural populations.

  3. [Effects of nitrogen application rate on faba bean fusarium wilt and rhizospheric microbial metabolic functional diversity].

    Science.gov (United States)

    Dong, Yan; Yang, Zhi-xian; Dong, Kun; Tang, Li; Zheng, Yi; Hu, Guo-bin

    2013-04-01

    A field plot experiment was conducted to study the effects of different nitrogen (N) application rates on the microbial functional diversity in faba bean rhizosphere and the relationships between the microbial functional diversity and the occurrence of faba bean fusarium wilt. Four nitrogen application rates were installed, i. e. , N0(0 kg hm-2 , N1 (56. 25 kg hm-2) , N2(112. 5 kg hm-2), and N3 (168.75 kg hm-2), and Biolog microbial analysis system was applied to study the damage of faba bean fusarium wilt and the rhizospheric microbial metabolic functional diversity. Applying N (N1 N2, and N3) decreased the disease index of faba bean fusarium wilt and the quantity of Fusarium oxysporum significantly, and increased the quantities of bacteria and actinomyces and the ratios of bacteria/fungi and actinomyces/fungi significantly, with the peak values of bacteria and actinomyces, bacteria/fungi, and actinomyces/fungi, and the lowest disease index and F. oxysporum density in N2. As compared with N0, applying N increased the AWCD value significantly, but the effects of different N application rates on the ability of rhizospheric microbes in utilizing six types of carbon sources had definite differences. Under the application of N, the utilization rates of carbohydrates, carboxylic acids, and amino acids by the rhizospheric microbes were higher. Principal component analysis demonstrated that applying N changed the rhizospheric microbial community composition obviously, and the carbohydrates, carboxylic acids, and amino acids were the sensitive carbon sources differentiating the changes of the microbial community induced by N application. Applying N inhibited the utilization of carbohydrates and carboxylic acids but improved the utilization of amino acids and phenolic acids by the rhizospheric microbes, which could be one of the main reasons of applying N being able to reduce the harm of faba bean fusarium wilt. It was suggested that rationally applying N could increase the

  4. Role of temperature on growth and metabolic rate in the tenebrionid beetles Alphitobius diaperinus and Tenebrio molitor.

    Science.gov (United States)

    Bjørge, Julie Dahl; Overgaard, Johannes; Malte, Hans; Gianotten, Natasja; Heckmann, Lars-Henrik

    2018-03-10

    Insects are increasingly used as a dietary source for food and feed and it is therefore important to understand how rearing conditions affect growth and development of these agricultural animals. Temperature is arguably the most important factor affecting metabolism and growth rate in insects. Here, we investigated how rearing temperature affected growth rate, growth efficiency and macronutrient composition in two species of edible beetle larvae: Alphitobius diaperinus and Tenebrio molitor. Growth rates of both species were quantified at temperatures ranging from 15.2 to 38.0 °C after which we measured protein and lipid content of the different treatment groups. Metabolic rate was measured in a similar temperature range by measuring the rate of O 2 consumption (V·O 2 ) and CO 2 production (V·CO 2 ) using repeated measures closed respirometry. Using these measurements, we calculated the growth efficiency of mealworms by relating the energy assimilation rate to the metabolic rate. Maximum daily growth rates were 18.3% and 16.6% at 31 °C, for A. diaperinus and T. molitor respectively, and we found that A. diaperinus was better at maintaining growth at high temperatures while T. molitor had superior growth at lower temperatures. Both species had highest efficiencies of energy assimilation in the temperature range of 23.3-31.0 °C, with values close to 2 J assimilated/J metabolised in A. diaperinus and around 4 J assimilated/J metabolised in T. molitor. Compared to "conventional" terrestrial livestock, both species of insects were characterised by high growth rates and very high energy conversion efficiency at most experimental temperatures. For A. diaperinus, lipid content was approximately 30% of dry mass and protein content approximately 50% of dry mass across most temperatures. Temperature had a greater influence on the body composition of T. molitor. At 31.0 °C the lipid and protein content was measured to 47.4% and 37.9%, respectively but lipid

  5. Intraspecific allometry of standard metabolic rate in green iguanas, Iguana iguana.

    Science.gov (United States)

    Maxwell, Lara K; Jacobson, Elliott R; McNab, Brian K

    2003-10-01

    To study the allometric relationship between standard metabolic rate and body mass (mass range 16-3627 g) in green iguanas, Iguana iguana (n=32), we measured rates of oxygen consumption (V(O(2))) at 30 degrees C during scotophase. The relationship could be described as: V(O(2))(ml h(-1))=0.478W(0.734). The resulting mass exponent was similar to the 3/4 power commonly used in interspecific curves (P>0.05), but differed from a proposed intraspecific value of 2/3 (Piguanas did not differ (P>0.05). The mass adjusted V(O(2)) was higher than predicted from generalized squamate curves. The mean mass exponent of intra-individual allometric equations of iguanas (n=7) at varying masses during ontogeny did not differ from that of the pooled equation, indicating that scaling of V(O(2)) is similar for both between and within individuals. Thermal acclimation, compensatory changes in V(O(2)) with prolonged exposure to a constant temperature, was not observed in juvenile iguanas (n=11) between 1 and 5 weeks of acclimation at 30 degrees C.

  6. Energetic fitness: Field metabolic rates assessed via 3D accelerometry complement conventional fitness metrics

    Science.gov (United States)

    Grémillet, David; Lescroël, Amelie; Ballard, Grant; Dugger, Katie M.; Massaro, Melanie; Porzig, Elizabeth L.; Ainley, David G.

    2018-01-01

    Evaluating the fitness of organisms is an essential step towards understanding their responses to environmental change. Connections between energy expenditure and fitness have been postulated for nearly a century. However, testing this premise among wild animals is constrained by difficulties in measuring energy expenditure while simultaneously monitoring conventional fitness metrics such as survival and reproductive output.We addressed this issue by exploring the functional links between field metabolic rate (FMR), body condition, sex, age and reproductive performance in a wild population.We deployed 3D accelerometers on 115 Adélie penguins Pygoscelis adeliae during four breeding seasons at one of the largest colonies of this species, Cape Crozier, on Ross Island, Antarctica. The demography of this population has been studied for the past 18 years. From accelerometry recordings, collected for birds of known age and breeding history, we determined the vector of the dynamic body acceleration (VeDBA) and used it as a proxy for FMR.This allowed us to demonstrate relationships among FMR, a breeding quality index (BQI) and body condition. Notably, we found a significant quadratic relationship between mean VeDBA during foraging and BQI for experienced breeders, and individuals in better body condition showed lower rates of energy expenditure.We conclude that using FMR as a fitness component complementary to more conventional fitness metrics will yield greater understanding of evolutionary and conservation physiology.

  7. 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.

  8. The effect of psychological stress on diet-induced thermogenesis and resting metabolic rate.

    Science.gov (United States)

    Weststrate, J A; Van der Kooy, K; Deurenberg, P; Hautvast, J G

    1990-04-01

    The effect of psychological stress on resting metabolic rate (RMR) and diet-induced thermogenesis (DIT) was assessed in 12 healthy young non-obese men of body weight 70.2 +/- 1.2 kg (mean +/- s.e.m.) and age 25 +/- 0.6 years. Two types of commercially available motion pictures (video films) were shown to the subjects during the measurements, ie stress-inducing horror films and as a control, romantic family films. The study was conducted according to a cross-over design. RMR and respiratory quotients were not significantly influenced by the type of film shown to the subjects. DIT, assessed over 4 h, was significantly increased by the stress-inducing treatment, 0.95 +/- 0.05 kJ/min (mean +/- s.e.m.) versus 0.76 +/- 0.06 kJ/min (control). No significant effect was observed of psychological stress on postprandial substrate oxidation rates, nutrient balances, and urinary catecholamine excretion.

  9. 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...

  10. Community-based primary prevention programs decrease the rate of metabolic syndrome among socioeconomically disadvantaged women.

    Science.gov (United States)

    Gilstrap, Lauren Gray; Malhotra, Rajeev; Peltier-Saxe, Donna; Slicas, Donna; Pineda, Eliana; Culhane-Hermann, Catherine; Cook, Nakela; Fernandez-Golarz, Carina; Wood, Malissa

    2013-04-01

    Metabolic Syndrome (MetSyn) is one of the strongest predictors of type 2 diabetes (DM2) and cardiovascular disease (CVD). It is associated with a 4- to 10-fold increased risk of DM2 and a 2- to 3-fold increased risk of CVD. Low income and minority women have some of the highest rates of MetSyn. This study examines the effect of a unique, community based, primary prevention program on the rates of MetSyn and health habits. Sixty-four low income and minority women were enrolled in the HAPPY (Health Awareness and Primary Prevention in Your neighborhood) Heart Program in an eastern suburb of Boston. Over these 2 years, patients were evaluated by an interdisciplinary medical team: their primary physician, cardiologist, nutritionist, physical therapist, and health coach. The rate of MetSyn was measured at baseline, year 1, and year 2. Comparisons were made either using the paired t test for normally distributed variables or the Wilcoxon Sign test for non-normal variables. The rate of MetSyn fell from 64.7% at baseline to 34.9% at year 1 (p=0.01) and 28.2% at year 2 (p<0.001). This was driven by increases in high-density lipoprotein (HDL-C) (p<0.001) and decreases in blood pressure (p=0.05). Fasting blood glucose trended down, but the hemoglobin A1c (HbA1c) reached significance (decreasing from 6 to 5.8, p<0.01). Nutrition and exercise habits trended toward improvement. There were significant decreases in anxiety (p<0.001), depression (p=0.006) and stress (p=0.002). This lifestyle intervention program is effective at decreasing MetSyn in a socioeconomically disadvantaged, largely minority, female population. This program also decreases anxiety, stress, and depression among participants.

  11. Validity of predictive equations for basal metabolic rate in Japanese adults.

    Science.gov (United States)

    Miyake, Rieko; Tanaka, Shigeho; Ohkawara, Kazunori; Ishikawa-Takata, Kazuko; Hikihara, Yuki; Taguri, Emiko; Kayashita, Jun; Tabata, Izumi

    2011-01-01

    Many predictive equations for basal metabolic rate (BMR) based on anthropometric measurements, age, and sex have been developed, mainly for healthy Caucasians. However, it has been reported that many of these equations, used widely, overestimate BMR not only for Asians, but also for Caucasians. The present study examined the accuracy of several predictive equations for BMR in Japanese subjects. In 365 healthy Japanese male and female subjects, aged 18 to 79 y, BMR was measured in the post-absorptive state using a mask and Douglas bag. Six predictive equations were examined. Total error was used as an index of the accuracy of each equation's prediction. Predicted BMR values by Dietary Reference Intakes for Japanese (Japan-DRI), Adjusted Dietary Reference Intakes for Japanese (Adjusted-DRI), and Ganpule equations were not significantly different from the measured BMR in either sex. On the other hand, Harris-Benedict, Schofield, and Food and Agriculture Organization of the United Nations/World Health Organization/United Nations University equations were significantly higher than the measured BMR in both sexes. The prediction error by Japan-DRI, Adjusted-DRI, and Harris-Benedict equations was significantly correlated with body weight in both sexes. Total error using the Ganpule equation was low in both males and females (125 and 99 kcal/d, respectively). In addition, total error using the Adjusted-DRI equation was low in females (95 kcal/d). Thus, the Ganpule equation was the most accurate in predicting BMR in our healthy Japanese subjects, because the difference between the predicted and measured BMR was relatively small, and body weight had no effect on the prediction error.

  12. 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.

  13. 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…

  14. Brain Size and Cerebral Glucose Metabolic Rate in Nonspecific Retardation and Down Syndrome.

    Science.gov (United States)

    Haier, Richard J.; And Others

    1995-01-01

    Brain size and cerebral glucose metabolic rate were determined for 10 individuals with mild mental retardation (MR), 7 individuals with Down syndrome (DS), and 10 matched controls. MR and DS groups both had brain volumes of about 80% compared to controls, with variance greatest within the MR group. (SLD)

  15. Basal metabolic rate scaled to body mass within species by the ...

    African Journals Online (AJOL)

    Basal metabolic rate scaled to body mass within species by the fractal dimension of the vascular system and body composition. ... The postulate bd = c is shown to hold for both these species within the limits of experimental error, with the crucian carp evidence being especially convincing, since b, c and d are estimated from ...

  16. 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''

  17. Heart rate variability analysed by Poincaré plot in patients with metabolic syndrome

    Czech Academy of Sciences Publication Activity Database

    Kubíčková, A.; Kozumplík, J.; Nováková, Z.; Plachý, M.; Jurák, Pavel; Lipoldová, J.

    2016-01-01

    Roč. 49, č. 1 (2016), s. 23-28 ISSN 0022-0736 R&D Projects: GA ČR GAP102/12/2034 Institutional support: RVO:68081731 Keywords : heart rate variability * metabolic syndrome * Poincaré plot * tilt table test * controlled breathing Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.514, year: 2016

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

    African Journals Online (AJOL)

    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 skeletal muscle during exercise and BMR to respiration in the viscera during rest. It follows, therefore, from the self-similarity of the vascular system that BMR is ...

  19. High basal metabolic rates in shorebirds while in the Arctic: a circumpolar view

    NARCIS (Netherlands)

    Lindström, A.; Klaassen, M.R.J.

    2003-01-01

    The basal metabolic rate (BMR) of Old World long-distance-migrant shorebirds has been found to vary along their migration route. On average, BMR is highest in the Arctic at the start of fall migration, intermediate at temperate latitudes, and lowest on the tropical wintering grounds. As a test of

  20. Original communication: Basal metabolic rate in children with a solid tumor

    NARCIS (Netherlands)

    Broeder, den E.; Oeseburg, B.; Lippens, R.J.J.; Staveren, van W.A.; Sengers, R.C.A.; Hof, van 't M.A.; Tolboom, J.J.M.

    2001-01-01

    Objective: To study the level of and changes in basal metabolic rate (BMR) in children with a solid tumour at diagnosis and during treatment in order to provide a more accurate estimate of energy requirements for nutritional support. Design: An observational study. Setting: Tertiary care at the

  1. Differential metabolic rates in prefrontal and temporal Brodmann areas in schizophrenia and schizotypal personality disorder.

    Science.gov (United States)

    Buchsbaum, Monte S; Nenadic, Igor; Hazlett, Erin A; Spiegel-Cohen, Jacqueline; Fleischman, Michael B; Akhavan, Arash; Silverman, Jeremy M; Siever, Larry J

    2002-03-01

    In an exploration of the schizophrenia spectrum, we compared cortical metabolic rates in unmedicated patients with schizophrenia and schizotypal personality disorder (SPD) with findings in age- and sex-matched normal volunteers. Coregistered magnetic resonance imaging (MRI) and positron emission tomography (PET) scans were obtained in 27 schizophrenic, 13 SPD, and 32 normal volunteers who performed a serial verbal learning test during tracer uptake. A template of Brodmann areas derived from a whole brain histological section atlas was used to analyze PET findings. Significantly lower metabolic rates were found in prefrontal areas 44-46 in schizophrenic patients than in normal volunteers. SPD patients did not differ from normal volunteers in most lateral frontal regions, but they had values intermediate between those of normal volunteers and schizophrenic patients in lateral temporal regions. SPD patients showed higher than normal metabolic rates in both medial frontal and medial temporal areas. Metabolic rates in Brodmann area 10 were distinctly higher in SPD patients than in either normal volunteers or schizophrenic patients.

  2. 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

  3. Hypothermia reduces cerebral metabolic rate and cerebral blood flow in newborn pigs

    International Nuclear Information System (INIS)

    Busija, D.W.; Leffler, C.W.

    1987-01-01

    The authors examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-μm radioactive microspheres. Regional CBF ranged from 44 to 66 ml·min -1 ·100 g -1 , and cerebral metabolic rate was 1.94 ± 0.23 ml O 2 ·100 g -1 ·min -1 during normothermia (39 degree C). Reduction of rectal temperature to 34-35 degree C decreased CBF and cerebral metabolic rate 40-50%. In another group of piglets, they examined responsiveness of the cerebral circulation to arterial hypercapnia during hypothermia. Although absolute values for normocapnic and hypercapnic CBF were reduced by hypothermia and absolute values for normocapnic and hypercapnic cerebrovascular resistance were increased, the percentage changes from control in these variables during hypercapnia were similar during normothermia and hypothermia. In another group of animals that were maintained normothermic and exposed to two episodes of hypercapnia, there was no attenuation of cerebrovascular dilation during the second episode. They conclude that hypothermia reduces CBF secondarily to a decrease in cerebral metabolic rate and that percent dilator responsiveness to arterial hypercapnia is unaltered when body temperature is reduced

  4. 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...

  5. 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. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  6. Association of metabolic syndrome and change in Unified Parkinson's Disease Rating Scale scores.

    Science.gov (United States)

    Leehey, Maureen; Luo, Sheng; Sharma, Saloni; Wills, Anne-Marie A; Bainbridge, Jacquelyn L; Wong, Pei Shieen; Simon, David K; Schneider, Jay; Zhang, Yunxi; Pérez, Adriana; Dhall, Rohit; Christine, Chadwick W; Singer, Carlos; Cambi, Franca; Boyd, James T

    2017-10-24

    To explore the association between metabolic syndrome and the Unified Parkinson's Disease Rating Scale (UPDRS) scores and, secondarily, the Symbol Digit Modalities Test (SDMT). This is a secondary analysis of data from 1,022 of 1,741 participants of the National Institute of Neurological Disorders and Stroke Exploratory Clinical Trials in Parkinson Disease Long-Term Study 1, a randomized, placebo-controlled trial of creatine. Participants were categorized as having or not having metabolic syndrome on the basis of modified criteria from the National Cholesterol Education Program Adult Treatment Panel III. Those who had the same metabolic syndrome status at consecutive annual visits were included. The change in UPDRS and SDMT scores from randomization to 3 years was compared in participants with and without metabolic syndrome. Participants with metabolic syndrome (n = 396) compared to those without (n = 626) were older (mean [SD] 63.9 [8.1] vs 59.9 [9.4] years; p metabolic syndrome experienced an additional 0.6- (0.2) unit annual increase in total UPDRS ( p = 0.02) and 0.5- (0.2) unit increase in motor UPDRS ( p = 0.01) scores compared with participants without metabolic syndrome. There was no difference in the change in SDMT scores. Persons with Parkinson disease meeting modified criteria for metabolic syndrome experienced a greater increase in total UPDRS scores over time, mainly as a result of increases in motor scores, compared to those who did not. Further studies are needed to confirm this finding. NCT00449865. © 2017 American Academy of Neurology.

  7. 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.

  8. Comparative analyses of basal rate of metabolism in mammals: data selection does matter.

    Science.gov (United States)

    Genoud, Michel; Isler, Karin; Martin, Robert D

    2018-02-01

    Basal rate of metabolism (BMR) is a physiological parameter that should be measured under strictly defined experimental conditions. In comparative analyses among mammals BMR is widely used as an index of the intensity of the metabolic machinery or as a proxy for energy expenditure. Many databases with BMR values for mammals are available, but the criteria used to select metabolic data as BMR estimates have often varied and the potential effect of this variability has rarely been questioned. We provide a new, expanded BMR database reflecting compliance with standard criteria (resting, postabsorptive state; thermal neutrality; adult, non-reproductive status for females) and examine potential effects of differential selectivity on the results of comparative analyses. The database includes 1739 different entries for 817 species of mammals, compiled from the original sources. It provides information permitting assessment of the validity of each estimate and presents the value closest to a proper BMR for each entry. Using different selection criteria, several alternative data sets were extracted and used in comparative analyses of (i) the scaling of BMR to body mass and (ii) the relationship between brain mass and BMR. It was expected that results would be especially dependent on selection criteria with small sample sizes and with relatively weak relationships. Phylogenetically informed regression (phylogenetic generalized least squares, PGLS) was applied to the alternative data sets for several different clades (Mammalia, Eutheria, Metatheria, or individual orders). For Mammalia, a 'subsampling procedure' was also applied, in which random subsamples of different sample sizes were taken from each original data set and successively analysed. In each case, two data sets with identical sample size and species, but comprising BMR data with different degrees of reliability, were compared. Selection criteria had minor effects on scaling equations computed for large clades

  9. Non-invasive optical measurement of cerebral metabolism and hemodynamics in infants.

    Science.gov (United States)

    Lin, Pei-Yi; Roche-Labarbe, Nadege; Dehaes, Mathieu; Carp, Stefan; Fenoglio, Angela; Barbieri, Beniamino; Hagan, Katherine; Grant, P Ellen; Franceschini, Maria Angela

    2013-03-14

    Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO₂). Thus, measures of CMRO₂ are reflective of neuronal viability and provide critical diagnostic information, making CMRO₂ an ideal target for bedside measurement of brain health. Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases. Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO₂) as a surrogate for cerebral oxygen consumption. However, SO₂ is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO₂ are not sensitive enough to detect brain injury hours after the insult, because oxygen consumption and delivery reach equilibrium after acute transients. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO₂ (CMRO₂i). With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain

  10. Metabolic differentiation in biofilms as indicated by carbon dioxide production rates.

    Science.gov (United States)

    Bester, Elanna; Kroukamp, Otini; Wolfaardt, Gideon M; Boonzaaier, Leandro; Liss, Steven N

    2010-02-01

    The measurement of carbon dioxide production rates as an indication of metabolic activity was applied to study biofilm development and response of Pseudomonas sp. biofilms to an environmental disturbance in the form of a moving air-liquid interface (i.e., shear). A differential response in biofilm cohesiveness was observed after bubble perturbation, and the biofilm layers were operationally defined as either shear-susceptible or non-shear-susceptible. Confocal laser scanning microscopy and image analysis showed a significant reduction in biofilm thickness and biomass after the removal of the shear-susceptible biofilm layer, as well as notable changes in the roughness coefficient and surface-to-biovolume ratio. These changes were accompanied by a 72% reduction of whole-biofilm CO2 production; however, the non-shear-susceptible region of the biofilm responded rapidly after the removal of the overlying cells and extracellular polymeric substances (EPS) along with the associated changes in nutrient and O2 flux, with CO2 production rates returning to preperturbation levels within 24 h. The adaptable nature and the ability of bacteria to respond to environmental conditions were further demonstrated by the outer shear-susceptible region of the biofilm; the average CO2 production rate of cells from this region increased within 0.25 h from 9.45 +/- 5.40 fmol of CO2 x cell(-1) x h(-1) to 22.6 +/- 7.58 fmol of CO2 x cell(-1) x h(-1) when cells were removed from the biofilm and maintained in suspension without an additional nutrient supply. These results also demonstrate the need for sufficient monitoring of biofilm recovery at the solid substratum if mechanical methods are used for biofouling control.

  11. 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

  12. 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.

  13. Tradeoffs between metabolic rate and spiracular conductance in discontinuous gas exchange of Samia cynthia (Lepidoptera, Saturniidae).

    Science.gov (United States)

    Moerbitz, Christian; Hetz, Stefan K

    2010-05-01

    The insect tracheal system is a unique respiratory system, designed for maximum oxygen delivery at high metabolic demands, e.g. during activity and at high ambient temperatures. Therefore, large safety margins are required for tracheal and spiracular conductance. Spiracles are the entry to the tracheal system and play an important role in controlling discontinuous gas exchange (DGC) between tracheal system and atmosphere in moth pupae. We investigated the effect of modulated metabolic rate (by changing ambient temperature) and modulated spiracular conductance (by blocking all except one spiracles) on gas exchange patterns in Samia pupae. Both, spiracle blocking and metabolic rates, affected respiratory behavior in Samia cynthia pupae. While animals showed discontinuous gas exchange cycles at lower temperatures with unblocked spiracles, the respiratory patterns were cyclic at higher temperatures, with partly blocked spiracles or a combination of these two factors. The threshold for the transition from a discontinuous (DGC) to a cyclic gas exchange ((cyc)GE) was significantly higher in animals with unblocked spiracles (18.7 nmol g(-1) min(-1) vs. 7.9 nmol g(-1) min(-1)). These findings indicate an important influence of spiracle conductance on the DGC, which may occur mostly in insects showing high spiracular conductances and low metabolic rates. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. 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

  15. Length and GC content variability of introns among teleostean genomes in the light of the metabolic rate hypothesis.

    Directory of Open Access Journals (Sweden)

    Ankita Chaurasia

    Full Text Available A comparative analysis of five teleostean genomes, namely zebrafish, medaka, three-spine stickleback, fugu and pufferfish was performed with the aim to highlight the nature of the forces driving both length and base composition of introns (i.e., bpi and GCi. An inter-genome approach using orthologous intronic sequences was carried out, analyzing independently both variables in pairwise comparisons. An average length shortening of introns was observed at increasing average GCi values. The result was not affected by masking transposable and repetitive elements harbored in the intronic sequences. The routine metabolic rate (mass specific temperature-corrected using the Boltzmann's factor was measured for each species. A significant correlation held between average differences of metabolic rate, length and GC content, while environmental temperature of fish habitat was not correlated with bpi and GCi. Analyzing the concomitant effect of both variables, i.e., bpi and GCi, at increasing genomic GC content, a decrease of bpi and an increase of GCi was observed for the significant majority of the intronic sequences (from ∼ 40% to ∼ 90%, in each pairwise comparison. The opposite event, concomitant increase of bpi and decrease of GCi, was counter selected (from <1% to ∼ 10%, in each pairwise comparison. The results further support the hypothesis that the metabolic rate plays a key role in shaping genome architecture and evolution of vertebrate genomes.

  16. Length and GC content variability of introns among teleostean genomes in the light of the metabolic rate hypothesis.

    Science.gov (United States)

    Chaurasia, Ankita; Tarallo, Andrea; Bernà, Luisa; Yagi, Mitsuharu; Agnisola, Claudio; D'Onofrio, Giuseppe

    2014-01-01

    A comparative analysis of five teleostean genomes, namely zebrafish, medaka, three-spine stickleback, fugu and pufferfish was performed with the aim to highlight the nature of the forces driving both length and base composition of introns (i.e., bpi and GCi). An inter-genome approach using orthologous intronic sequences was carried out, analyzing independently both variables in pairwise comparisons. An average length shortening of introns was observed at increasing average GCi values. The result was not affected by masking transposable and repetitive elements harbored in the intronic sequences. The routine metabolic rate (mass specific temperature-corrected using the Boltzmann's factor) was measured for each species. A significant correlation held between average differences of metabolic rate, length and GC content, while environmental temperature of fish habitat was not correlated with bpi and GCi. Analyzing the concomitant effect of both variables, i.e., bpi and GCi, at increasing genomic GC content, a decrease of bpi and an increase of GCi was observed for the significant majority of the intronic sequences (from ∼ 40% to ∼ 90%, in each pairwise comparison). The opposite event, concomitant increase of bpi and decrease of GCi, was counter selected (from hypothesis that the metabolic rate plays a key role in shaping genome architecture and evolution of vertebrate genomes.

  17. 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)

    Thuesen, Erik V.; Childress, James J.

    1993-05-01

    Investigations of metabolic rate, enzyme activity and chemical composition were undertaken on two abundant deep-sea pelagic worms: Nectonemertes mirabilis (Nemertea; Hoplonemertinea) and Poeobius meseres (Annelida; Polychaeta). Six other species of worms ( Pelagonemertes brinkmanni (Nemertea) and the following polychaetes: Pelagobia species A, Tomopteris nisseni, Tomopteris pacifica, Tomopteris species A, and Traviopsis lobifera) were captured in smaller numbers and used for comparison in the physiological and biochemical measurements. Polychaete worms had the highest oxygen consumption rates and, along with N. mirabilis, displayed significant size effects on metabolic rate. Poeobius meseres had the lowest rates of oxygen consumption and displayed no significant relationship of oxygen consumption rate to wet weight. No significant effect of size on the activities of citrate synthase, lactate dehydrogenase or pyruvate kinase was observed in P. meseres or N. mirabilis. Lipid content was higher than protein content for all the worms in this study. Carbohydrate was of little significance in these worms and was usually metabolic rates. It appears that polychaete worms as a group have higher metabolic rates than bathypelagic shrimps, copepods and fishes, and may be the animals with the highest metabolic rates in the bathypelagic regions of the world's oceans.

  18. Adaptive changes in basal metabolic rate and thermogenesis in chronic undernutrition

    International Nuclear Information System (INIS)

    Shetty, P.S.

    1993-01-01

    Metabolic adaptation during chronic undernutrition represents a complex integration of several processes which affect the total energy expenditure of the individual. Basal metabolic rate (BMR) is reduced; reductions in BMR per unit fat free mass (FFM) is difficult to demonstrate. BMR changes in undernutrition reflect the low body weight as well as alterations in the composition of the FFM; more specifically changes in the ratio of viscera to muscle compartments of the FFM. Thermogenic responses to norepinephrine are transiently suppressed but recover rapidly on repeated stimulation. Dietary thermogenesis is enhanced possible the result of increases in tissue synthesis within the body. Changes in BMR and thermogenesis suggestive of an increase in metabolic efficiency is thus difficult to demonstrate in chronic undernutrition. (author). 15 refs, 2 figs, 7 tabs

  19. Predicting Basal Metabolic Rate in Men with Motor Complete Spinal Cord Injury.

    Science.gov (United States)

    Nightingale, Tom E; Gorgey, Ashraf S

    2018-01-08

    To assess the accuracy of existing basal metabolic rate (BMR) prediction equations in men with chronic (>1 year) spinal cord injury (SCI). The primary aim is to develop new SCI population-specific BMR prediction models, based on anthropometric, body composition and/or demographic variables that are strongly associated with BMR. Thirty men with chronic SCI (Paraplegic; n = 21, Tetraplegic; n = 9), aged 35 ± 11 years (mean ± SD) participated in this cross-sectional study. Criterion BMR values were measured by indirect calorimetry. Body composition (dual energy X-ray absorptiometry; DXA) and anthropometric measurements (circumferences and diameters) were also taken. Multiple linear regression analysis was performed to develop new SCI-specific BMR prediction models. Criterion BMR values were compared to values estimated from six existing and four developed prediction equations RESULTS: Existing equations that use information on stature, weight and/or age, significantly (P BMR by a mean of 14-17% (187-234 kcal/day). Equations that utilised fat-free mass (FFM) accurately predicted BMR. The development of new SCI-specific prediction models demonstrated that the addition of anthropometric variables (weight, height and calf circumference) to FFM (Model 3; r = 0.77), explained 8% more of the variance in BMR than FFM alone (Model 1; r = 0.69). Using anthropometric variables, without FFM, explained less of the variance in BMR (Model 4; r = 0.57). However, all the developed prediction models demonstrated acceptable mean absolute error ≤ 6%. BMR can be more accurately estimated when DXA derived FFM is incorporated into prediction equations. Utilising anthropometric measurements provides a promising alternative to improve the prediction of BMR, beyond that achieved by existing equations in persons with SCI.

  20. Total Body Capacitance for Estimating Human Basal Metabolic Rate in an Egyptian Population

    Science.gov (United States)

    M. Abdel-Mageed, Samir; I. Mohamed, Ehab

    2016-01-01

    Determining basal metabolic rate (BMR) is important for estimating total energy needs in the human being yet, concerns have been raised regarding the suitability of sex-specific equations based on age and weight for its calculation on an individual or population basis. It has been shown that body cell mass (BCM) is the body compartment responsible for BMR. The objectives of this study were to investigate the relationship between total body capacitance (TBC), which is considered as an expression for BCM, and BMR and to develop a formula for calculating BMR in comparison with widely used equations. Fifty healthy nonsmoking male volunteers [mean age (± SD): 24.93 ± 4.15 year and body mass index (BMI): 25.63 ± 3.59 kg/m2] and an equal number of healthy nonsmoking females matched for age and BMI were recruited for the study. TBC and BMR were measured for all participants using octopolar bioelectric impedance analysis and indirect calorimetry techniques, respectively. A significant regressing equation based on the covariates: sex, weight, and TBC for estimating BMR was derived (R=0.96, SEE=48.59 kcal, and P<0.0001), which will be useful for nutritional and health status assessment for both individuals and populations. PMID:27127453

  1. Thermal conductance and basal metabolic rate are part of a coordinated system for heat transfer regulation

    Science.gov (United States)

    Naya, Daniel E.; Spangenberg, Lucía; Naya, Hugo; Bozinovic, Francisco

    2013-01-01

    Thermal conductance measures the ease with which heat leaves or enters  an organism's body. Although the analysis of this physiological variable in relation to climatic and ecological factors can be traced to studies by Scholander and colleagues, only small advances have occurred ever since. Here, we analyse the relationship between minimal thermal conductance estimated during summer (Cmin) and several ecological, climatic and geographical factors for 127 rodent species, in order to identify the exogenous factors that have potentially affected the evolution of thermal conductance. In addition, we evaluate whether there is compensation between Cmin and basal metabolic rate (BMR)—in such a way that a scale-invariant ratio between both variables is equal to one—as could be expected from the Scholander–Irving model of heat transfer. Our major findings are (i) annual mean temperature is the best single predictor of mass-independent Cmin. (ii) After controlling for the effect of body mass, there is a strong positive correlation between log10 (Cmin) and log10 (BMR). Further, the slope of this correlation is close to one, indicating an almost perfect compensation between both physiological variables. (iii) Structural equation modelling indicated that Cmin values are adjusted to BMR values and not the other way around. Thus, our results strongly suggest that BMR and thermal conductance integrate a coordinated system for heat regulation in endothermic animals and that summer conductance values are adjusted (in an evolutionary sense) to track changes in BMRs. PMID:23902915

  2. Thermal conductance and basal metabolic rate are part of a coordinated system for heat transfer regulation.

    Science.gov (United States)

    Naya, Daniel E; Spangenberg, Lucía; Naya, Hugo; Bozinovic, Francisco

    2013-09-22

    Thermal conductance measures the ease with which heat leaves or enters an organism's body. Although the analysis of this physiological variable in relation to climatic and ecological factors can be traced to studies by Scholander and colleagues, only small advances have occurred ever since. Here, we analyse the relationship between minimal thermal conductance estimated during summer (Cmin) and several ecological, climatic and geographical factors for 127 rodent species, in order to identify the exogenous factors that have potentially affected the evolution of thermal conductance. In addition, we evaluate whether there is compensation between Cmin and basal metabolic rate (BMR)-in such a way that a scale-invariant ratio between both variables is equal to one-as could be expected from the Scholander-Irving model of heat transfer. Our major findings are (i) annual mean temperature is the best single predictor of mass-independent Cmin. (ii) After controlling for the effect of body mass, there is a strong positive correlation between log10 (Cmin) and log10 (BMR). Further, the slope of this correlation is close to one, indicating an almost perfect compensation between both physiological variables. (iii) Structural equation modelling indicated that Cmin values are adjusted to BMR values and not the other way around. Thus, our results strongly suggest that BMR and thermal conductance integrate a coordinated system for heat regulation in endothermic animals and that summer conductance values are adjusted (in an evolutionary sense) to track changes in BMRs.

  3. The role of gut microbiota in the regulation of standard metabolic rate in female Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Paul A. Ayayee

    2018-05-01

    Full Text Available Insect gut microbiota contribute significantly to host nutritional ecology. Disrupting insect gut microbial assemblages impacts nutrient provisioning functions, and can potentially affect host standard metabolic rate (SMR, a measure of host energy balance. In this study, we evaluated the effect of disrupting gut microbial assemblages on the SMR of female Periplaneta americana cockroaches fed dog food (DF, high protein/carbohydrate (p/c ratio, and cellulose-amended dog food (CADF, 30% dog food, 70% cellulose, low p/c ratio diets, supplemented with none, low, or high antibiotic doses. Bacterial loads decreased significantly between diet types (P = 0.04 and across antibiotic doses (P = 0.04. There was a significant diet type x antibiotic dose interaction on SMR of females on both diets (P = 0.05 by the end of the seven-day experimental period. In CADF-fed females, SMR decreased linearly with decreasing bacterial load. However, SMR of DF-fed females on the low dose was significantly higher than those in the control and high dose groups. This is interpreted as a diet-dependent response by low dose DF-fed females to the loss of nutritional services provided by gut bacteria. Severe reductions in bacterial load at high doses reduced SMR of females on both diet types. This study provides insights into the potential role of gut bacteria as modulators of host energy expenditure under varying dietary conditions.

  4. Radioiodinated free fatty acids; can we measure myocardial metabolism

    International Nuclear Information System (INIS)

    Visser, F.C.; Eenige, M.J. van; Duwel, C.M.B.; Roos, J.P.

    1986-01-01

    To investigate the feasibility of radioiodinated free fatty acids for ''metabolic imaging'', the kinetics and distribution pattern of metabolites of heptadecanoic acid I 131 (HDA I 131) were studied in canine myocardium throughout metabolic interventions. In control dogs and in dogs during glucose/insulin and sodium lactate infusion, biopsy specimens were taken during a go-min period after HDA I 131 administration and analyzed. Clearly distinct patterns of distribution and elimination were seen during the metabolic interventions, indicating the usefulness of iodinated fatty acids for metabolic studies. (orig.)

  5. Sex differences in metabolic rates in field crickets and their dipteran parasitoids.

    Science.gov (United States)

    Kolluru, G R; Chappell, M A; Zuk, M

    2004-11-01

    Sex differences in metabolic rate (MR) can result from dimorphism in the performance of energetically demanding activities. Male crickets (Teleogryllus oceanicus) engage in costly calling and aggressive activity not performed by females. Consistent with this difference, we found higher maximal MR, factorial scope, and fat content in males than females. T. oceanicus song is also costly because it attracts the parasitoid fly Ormia ochracea. Parasitized crickets had reduced maximal MR consistent with a metabolic cost to harboring larvae. This cost was greater for females, either because females invest more heavily into reproduction at the expense of metabolic capacity, or because males are under stronger selection to respond to infection. Little is known about O. ochracea outside of its auditory system and parasitic lifestyle. We observed greater resting MR in male flies, possibly reflecting a sex difference in the requirement for metabolic power output, because male flies perform potentially costly mating behavior not seen in females. We found a positive relationship between larval density within a cricket and pupal resting MR, suggesting that crickets in good condition are able to both harbor more larvae and produce larvae with higher resting MR. These results reveal a complex interplay between the metabolism of crickets and their fly parasitoids.

  6. 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

    The numbers of sulfate reducers in two Arctic sediments within situ temperatures of 2.6 and -1.7 degrees C were determined. Most-probable-number counts were higher at 10 degrees C than at 20 degrees C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates...... 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...... their mesophilic counterparts at similarly low temperatures....

  7. Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon).

    Science.gov (United States)

    Watson, Charles M; Burggren, Warren W

    2016-01-01

    Three congeneric lizards from the southeastern United States (Plestiodon fasciatus, P. inexpectatus, and P. laticeps) exhibit a unique nested distribution. All three skink species inhabit the US Southeast, but two extend northward to central Ohio (P. fasciatus and P. laticeps) and P. fasciatus extends well into Canada. Distinct interspecific differences in microhabitat selection and behavior are associated with the cooler temperatures of the more Northern ranges. We hypothesized that interspecific differences in metabolic temperature sensitivity locally segregates them across their total range. Resting oxygen consumption was measured at 20°, 25° and 30°C. Plestiodon fasciatus, from the coolest habitats, exhibited greatly elevated oxygen consumption compared to the other species at high ecologically-relevant temperatures (0.10, 0.17 and 0.83 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Yet, P. inexpectatus, from the warmest habitats, exhibited sharply decreased oxygen consumption compared to the other species at lower ecologically-relevant temperatures (0.09, 0.27 and 0.42 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Plestiodon laticeps, from both open and closed microhabitats and intermediate latitudinal range, exhibited oxygen consumptions significantly lower than the other two species (0.057, 0.104 and 0.172 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Overall, Plestiodon showed metabolic temperature sensitivities (Q10s) in the range of 2-3 over the middle of each species' normal temperature range. However, especially P. fasciatus and P. inexpectatus showed highly elevated Q10s (9 to 25) at the extreme ends of their temperature range. While morphologically similar, these skinks are metabolically distinct across the genus' habitat, likely having contributed to their current distribution.

  8. A transcription factor links growth rate and metabolism in the hypersaline adapted archaeon Halobacterium salinarum.

    Science.gov (United States)

    Todor, Horia; Dulmage, Keely; Gillum, Nicholas; Bain, James R; Muehlbauer, Michael J; Schmid, Amy K

    2014-09-01

    Co-ordinating metabolism and growth is a key challenge for all organisms. Despite fluctuating environments, cells must produce the same metabolic outputs to thrive. The mechanisms underlying this 'growth homeostasis' are known in bacteria and eukaryotes, but remain unexplored in archaea. In the model archaeon Halobacterium salinarum, the transcription factor TrmB regulates enzyme-coding genes in diverse metabolic pathways in response to glucose. However, H. salinarum is thought not to catabolize glucose. To resolve this discrepancy, we demonstrate that TrmB regulates the gluconeogenic production of sugars incorporated into the cell surface S-layer glycoprotein. Additionally, we show that TrmB-DNA binding correlates with instantaneous growth rate, likely because S-layer glycosylation is proportional to growth. This suggests that TrmB transduces a growth rate signal to co-regulated metabolic pathways including amino acid, purine, and cobalamin biosynthesis. Remarkably, the topology and function of this growth homeostatic network appear conserved across domains despite extensive alterations in protein components. © 2014 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  9. Heart Rate Measures of Flight Test and Evaluation

    National Research Council Canada - National Science Library

    Bonner, Malcolm A; Wilson, Glenn F

    2001-01-01

    .... Because flying is a complex task, several measures are required to derive the best evaluation. This article describes the use of heart rate to augment the typical performance and subjective measures used in test and evaluation...

  10. The effect of temperature and body weight on the routine metabolic rate and postprandial metabolic response in mulloway, Argyrosomus japonicus.

    Science.gov (United States)

    Pirozzi, Igor; Booth, Mark A

    2009-09-01

    Specific dynamic action (SDA) is the energy expended on the physiological processes associated with meal digestion and is strongly influenced by the characteristics of the meal and the body weight (BW) and temperature of the organism. This study assessed the effects of temperature and body weight on the routine metabolic rate (RMR) and postprandial metabolic response in mulloway, Argyrosomus japonicus. RMR and SDA were established at 3 temperatures (14, 20 and 26 degrees C). 5 size classes of mulloway ranging from 60 g to 1.14 kg were used to establish RMR with 3 of the 5 size classes (60, 120 and 240 g) used to establish SDA. The effect of body size on the mass-specific RMR (mg O(2) kg(-1) h(-1)) varied significantly depending on the temperature; there was a greater relative increase in the mass-specific RMR for smaller mulloway with increasing temperature. No statistical differences were found between the mass exponent (b) values at each temperature when tested against H(0): b=0.8. The gross RMR of mulloway (mg O(2) fish(-1) h(-1)) can be described as function of temperature (T; 14-26 degrees C) as: (0.0195T-0.0454)BW(g)(0.8) and the mass-specific RMR (mg O(2) kg(-1) h(-1)) can be described as: (21.042T-74.867)BW(g)(-0.2). Both SDA duration and time to peak SDA were influenced by temperature and body weight; SDA duration occurred within 41-89 h and peak time occurred within 17-38 h of feeding. The effect of body size on peak metabolic rate varied significantly depending on temperature, generally increasing with temperature and decreasing with increasing body size. Peak gross oxygen consumption (MO(2): mg O(2) fish(-1) h(-1)) scaled allometrically with BW. Temperature, but not body size, significantly affected SDA scope, although the difference was numerically small. There was a trend for MO(2) above RMR over the SDA period to increase with temperature; however, this was not statistically significant. The average proportion of energy expended over the SDA period

  11. 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 dark period activity (1188 vs. 710 activity counts/h). This corresponded to higher (p energy intake (mean over 12-week period: 196 vs. 187 kcal/day), and increased (p = 0.048) RMR in LD 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.

  12. Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

    International Nuclear Information System (INIS)

    Boas, D A; Strangman, G; Culver, J P; Hoge, R D; Jasdzewski, G; Poldrack, R A; Rosen, B R; Mandeville, J B

    2003-01-01

    We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO 2 ) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO 2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO 2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO 2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO 2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO 2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI

  13. 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.

  14. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  15. 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

  16. Efficiency of rate and latency coding with respect to metabolic cost and time

    Czech Academy of Sciences Publication Activity Database

    Leváková, Marie

    2017-01-01

    Roč. 161, Nov 2017 (2017), s. 31-40 ISSN 0303-2647 R&D Projects: GA ČR(CZ) GA15-08066S Institutional support: RVO:67985823 Keywords : rate coding * temporal coding * metabolic cost * Fisher information Subject RIV: BD - Theory of Information OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 1.652, year: 2016

  17. TT Mutant Homozygote of Kruppel-like Factor 5 Is a Key Factor for Increasing Basal Metabolic Rate and Resting Metabolic Rate in Korean Elementary School Children.

    Science.gov (United States)

    Choi, Jung Ran; Kwon, In-Su; Kwon, Dae Young; Kim, Myung-Sunny; Lee, Myoungsook

    2013-12-01

    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 BMR (adjust r(2) = 1.000, p BMR in Korean children. We could make better use of the variation within KLF5 in a future clinical intervention study of obesity.

  18. 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.

  19. Metabolic equivalents of task are confounded by adiposity, which disturbs objective measurement of physical activity

    Directory of Open Access Journals (Sweden)

    Tuomo T Tompuri

    2015-08-01

    Full Text Available Physical activity refers any bodily movements produced by skeletal muscles that expends energy. Hence the amount and the intensity of physical activity can be assessed by energy expenditure. Metabolic equivalents of task (MET are multiplies of the resting metabolism reflecting metabolic rate during exercise. The standard MET is defined as 3.5 ml/min/kg. However, the expression of energy expenditure by body weight to normalize the size differences between subjects causes analytical hazards: scaling by body weight does not have a physiological, mathematical, or physical rationale. This review demonstrates by examples that false methodology may cause paradoxical observations if physical activity would be assessed by body weight scaled values such as standard METs. While standard METs are confounded by adiposity, lean mass proportional measures of energy expenditure would enable a more truthful choice to assess physical activity. While physical activity as a behavior and cardiorespiratory fitness or adiposity as a state represents major determinants of public health, specific measurements of health determinants must be understood to enable a truthful evaluation of the interactions and their independent role as a health predictor.

  20. Eddy-current flow rate meter for measuring sodium flow rates

    International Nuclear Information System (INIS)

    Knaak, J.

    1976-01-01

    For safety reasons flow rate meters for monitoring coolant flow rates are inserted in the core of sodium-cooled fast breeder reactors. These are so-called eddy-current flow rate meters which can be mounted directly above the fuel elements. In the present contribution the principle of measurement, the mechanical construction and the circuit design of the flow rate measuring device are described. Special problems and their solution on developing the measuring system are pointed out. Finally, results of measurement and experience with the apparatus in several experiments are reported, where also further possibilities of application were tested. (orig./TK) [de

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

    DEFF Research Database (Denmark)

    Nielsen, Jens Bredal

    1997-01-01

    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...... 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...

  2. 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 ( R 2 =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.

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

    Science.gov (United States)

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

    2018-04-04

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

  4. Device accurately measures and records low gas-flow rates

    Science.gov (United States)

    Branum, L. W.

    1966-01-01

    Free-floating piston in a vertical column accurately measures and records low gas-flow rates. The system may be calibrated, using an adjustable flow-rate gas supply, a low pressure gage, and a sequence recorder. From the calibration rates, a nomograph may be made for easy reduction. Temperature correction may be added for further accuracy.

  5. Positron emission tomography for measuring metabolism in vivo

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    1985-01-01

    Nuclear medical imaging always relates to changes at the cellular or molecular level of organization of the body. For years, such changes, summarily called metabolism, permitted radionuclides as tracers to produce information on rather gross organ structure and function. Yet, more recently, increasing emphasis is placed on metabolic reactions themselves; this development is of considerable promise to the clinician, because disease begins and nearly always expresses itself by alterations of metabolism. PET greatly helps to investigate and describe in vivo individual steps within the complex network of enzyme catalized reactions that maintain life; in fact, PET allows studies of biochemistry in vivo. (Author)

  6. Gaucher disease type I: assessment of basal metabolic rate in patients from southern Brazil.

    Science.gov (United States)

    Doneda, Divair; Lopes, André L; Oliveira, Alvaro R; Netto, Cristina B; Moulin, Cileide C; Schwartz, Ida V D

    2011-01-15

    Gaucher disease (GD) is characterized by clinical heterogeneity and is associated with metabolic abnormalities such as increased resting energy expenditure. To assess the basal metabolic rate (BMR) of patients with GD type I followed at the Gaucher Disease Reference Center of Rio Grande do Sul, Brazil. Fourteen patients (male=6) and 14 healthy controls matched by gender, age and body mass index (BMI) were included in the study. The nutritional status of patients was assessed by BMI. The BMR was measured by indirect calorimetry. In two patients, it was possible to perform BMR in the pre- and the post-treatment periods. Mean age and BMI of patients and controls were, respectively, 32.8 ± 17.6 and 32.1 ± 16.6 years and 23.3 ± 3.1 and 22.4 ± 3.1 kg/m(2). Twelve patients were receiving enzyme replacement therapy (ERT) with imiglucerase (mean duration of treatment=5.2 ± 4.3 years; mean dosage of imiglucerase=24.2 ± 7.3 UI/kg/inf). Five patients (36%) were overweight, and nine (64%) were normal weight. Mean BMR of patients on ERT was 27.1% higher than that of controls (p=0.007). There was no difference between the BMR of patients on ERT and not on ERT (n=4) (p=0.92). Comparing the BMR of patients on ERT and their controls with the BMR estimated by the Harris-Benedict equation, the BMR of patients was 6.3% higher than the estimated (p = 0.1), while the BMR of their controls was 17.0% lower than the estimated (p = 0.001). Most treated GD type I patients were normal weight. The patients including those on ERT showed higher BMR when compared to controls. Imiglucerase is probably unable to normalize the hypermetabolism presented by GD type I patients. Additional studies should be performed to confirm our findings. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. Resistive Wall Growth Rate Measurements in the Fermilab Recycler

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, R. [Fermilab; Adamson, P. [Fermilab; Burov, A. [Fermilab; Kourbanis, I. [Fermilab

    2016-10-05

    Impedance could represent a limitation of running high intensity beams in the Fermilab recycler. With high intensity upgrades foreseen, it is important to quantify the impedance. To do this,studies have been performed measuring the growth rate of presumably the resistive wall instability. The growth rates at varying intensities and chromaticities are shown. The measured growth rates are compared to ones calculated with the resistive wall impedance.

  8. 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.

  9. Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

    2004-05-01

    Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

  10. In situ measurements of dose rates from terrestrial gamma rays

    International Nuclear Information System (INIS)

    Horng, M.C.; Jiang, S.H.

    2002-01-01

    A portable, high purity germanium (HPGe) detector was employed for the performance of in situ measurements of radionuclide activity concentrations in the ground in Taiwan, at altitudes ranging from sea level to 3900 m. The absolute peak efficiency of the HPGe detector for a gamma-ray source uniformly distributed in the semi-infinite ground was determined using a semi-empirical method. The gamma-ray dose rates from terrestrial radionuclides were calculated from the measured activity levels using recently published dose rate conversion factors. The absorbed dose rate in air due to cosmic rays was derived by subtracting the terrestrial gamma-ray dose rate from the overall absorbed dose rate in air measured using a high-pressure ionization chamber. The cosmic-ray dose rate calculated as a function of altitude, was found to be in good agreement with the data reported by UNSCEAR. (orig.)

  11. Comparability of slack water and Lagrangian flow respirometry methods for community metabolic measurements.

    Directory of Open Access Journals (Sweden)

    Emily C Shaw

    Full Text Available Coral reef calcification is predicted to decline as a result of ocean acidification and other anthropogenic stressors. The majority of studies predicting declines based on in situ relationships between environmental parameters and net community calcification rate have been location-specific, preventing accurate predictions for coral reefs globally. In this study, net community calcification and production were measured on a coral reef flat at One Tree Island, Great Barrier Reef, using Lagrangian flow respirometry and slack water methods. Net community calcification, daytime net photosynthesis and nighttime respiration were higher under the flow respirometry method, likely due to increased water flow relative to the slack water method. The two methods also varied in the degrees to which they were influenced by potential measurement uncertainties. The difference in the results from these two commonly used methods implies that some of the location-specific differences in coral reef community metabolism may be due to differences in measurement methods.

  12. Aquatic respiration rate measurements at low oxygen concentrations.

    Directory of Open Access Journals (Sweden)

    Moritz Holtappels

    Full Text Available Despite its huge ecological importance, microbial oxygen respiration in pelagic waters is little studied, primarily due to methodological difficulties. Respiration measurements are challenging because of the required high resolution of oxygen concentration measurements. Recent improvements in oxygen sensing techniques bear great potential to overcome these limitations. Here we compare 3 different methods to measure oxygen consumption rates at low oxygen concentrations, utilizing amperometric Clark type sensors (STOX, optical sensors (optodes, and mass spectrometry in combination with (18-18O2 labeling. Oxygen concentrations and consumption rates agreed well between the different methods when applied in the same experimental setting. Oxygen consumption rates between 30 and 400 nmol L(-1 h(-1 were measured with high precision and relative standard errors of less than 3%. Rate detection limits in the range of 1 nmol L(-1 h(-1 were suitable for rate determinations in open ocean water and were lowest at the lowest applied O2 concentration.

  13. Radiographic and metabolic response rates following image-guided stereotactic radiotherapy for lung tumors

    International Nuclear Information System (INIS)

    Mohammed, Nasiruddin; Grills, Inga S.; Wong, Ching-Yee Oliver; Galerani, Ana Paula; Chao, Kenneth; Welsh, Robert; Chmielewski, Gary; Yan Di; Kestin, Larry L.

    2011-01-01

    Purpose: To evaluate radiographic and metabolic response after stereotactic body radiotherapy (SBRT) for early lung tumors. Materials and methods: Thirty-nine tumors were treated prospectively with SBRT (dose = 48-60 Gy, 4-5 Fx). Thirty-six cases were primary NSCLC (T1N0 = 67%; T2N0 = 25%); three cases were solitary metastases. Patients were followed using CT and PET at 6, 16, and 52 weeks post-SBRT, with CT follow-up thereafter. RECIST and EORTC criteria were used to evaluate CT and PET responses. Results: At median follow-up of 9 months (0.4-26), RECIST complete response (CR), partial response (PR), and stable disease (SD) rates were 3%, 43%, 54% at 6 weeks; 15%, 38%, 46% at 16 weeks; 27%, 64%, 9% at 52 weeks. Mean baseline tumor volume was reduced by 46%, 70%, 87%, and 96%, respectively at 6, 16, 52, and 72 weeks. Mean baseline maximum standardized uptake value (SUV) was 8.3 (1.1-20.3) and reduced to 3.4, 3.0, and 3.7 at 6, 16, and 52 weeks after SBRT. EORTC metabolic CR/PR, SD, and progressive disease rates were 67%, 22%, 11% at 6 weeks; 86%, 10%, 3% at 16 weeks; 95%, 5%, 0% at 52 weeks. Conclusions: SBRT yields excellent RECIST and EORTC based response. Metabolic response is rapid however radiographic response occurs even after 1-year post treatment.

  14. Phylogenetic differences of mammalian basal metabolic rate are not explained by mitochondrial basal proton leak.

    Science.gov (United States)

    Polymeropoulos, E T; Heldmaier, G; Frappell, P B; McAllan, B M; Withers, K W; Klingenspor, M; White, C R; Jastroch, M

    2012-01-07

    Metabolic rates of mammals presumably increased during the evolution of endothermy, but molecular and cellular mechanisms underlying basal metabolic rate (BMR) are still not understood. It has been established that mitochondrial basal proton leak contributes significantly to BMR. Comparative studies among a diversity of eutherian mammals showed that BMR correlates with body mass and proton leak. Here, we studied BMR and mitochondrial basal proton leak in liver of various marsupial species. Surprisingly, we found that the mitochondrial proton leak was greater in marsupials than in eutherians, although marsupials have lower BMRs. To verify our finding, we kept similar-sized individuals of a marsupial opossum (Monodelphis domestica) and a eutherian rodent (Mesocricetus auratus) species under identical conditions, and directly compared BMR and basal proton leak. We confirmed an approximately 40 per cent lower mass specific BMR in the opossum although its proton leak was significantly higher (approx. 60%). We demonstrate that the increase in BMR during eutherian evolution is not based on a general increase in the mitochondrial proton leak, although there is a similar allometric relationship of proton leak and BMR within mammalian groups. The difference in proton leak between endothermic groups may assist in elucidating distinct metabolic and habitat requirements that have evolved during mammalian divergence.

  15. [Resting metabolic rate estimated by bioelectrical impedance analysis and its determinants in maintenance hemodialysis patients].

    Science.gov (United States)

    Da, J J; Peng, H Y; Lin, X; Shen, Y; Zhao, J Q; He, S; Zha, Y

    2018-03-27

    Objective: To explore the level of resting energy expenditure (REE) estimated by bioelectrical impedance analysis and the association of resting metabolic rate (RMR) with clinical related factors, and provide new ideas for improving protein energy wasting (PEW) in maintenance hemodialysis (MHD) patients. Methods: Seven hundred and sixty-five subjects receiving MHD between July 2015 and September 2016 in 11 hemodialysis centers in Guizhou province were enrolled in this cross-sectional study. Bioelectrical impedance analysis was used to measure RMR and body composition, such as lean body mass, fat mass and body cell mass (BCM). Baseline characteristics, routine blood test indexes and biochemical data of hemodialysis patients were collected. The level of RMR and body composition in hemodialysis patients was compared by gender grouping. Then the patients were divided into four groups according to the cutoff value of RMR quartile. Spearman correlation analysis and multiple linear regression analysis were used to analyze the relationships between RMR and clinical related factors. Results: The average age of MHD patients was (54.96±15.78) years and the duriation of dialysis was (42.3±9.0) months. The level of RMR in male patients (474 cases, 61.96%) was significantly higher than that in female patients [1 591(1 444, 1 764) kcal/d vs 1 226 (1 104, 1 354) kcal/d, P lean body mass ( P =0.193). Multiple linear regression analysis showed that RMR was positively correlated with body surface area (β=0.817) and lactate dehydrogenase (LDH) (β=0.198), and negatively correlated with age (β=-0.141), all P maintenance hemodialysis are associated with lactate dehydrogenase level, which may become a new index to evaluate energy consumption.

  16. 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.

  17. Rating PV Power and Energy: Cell, Module, and System Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Emery, Keith

    2016-06-02

    A summary of key points related to research-level measurements of current vs. voltage measurement theory including basic PV operation, equivalent circuit, and concept of spectral error; PV power performance including PV irradiance sensors, simulators and commercial and generic I-V systems; PV measurement artifacts, intercomparisons, and alternative rating methods.

  18. Metabolic Effects of Cholecystectomy: Gallbladder Ablation Increases Basal Metabolic Rate through G-Protein Coupled Bile Acid Receptor Gpbar1-Dependent Mechanisms in Mice

    Science.gov (United States)

    Cortés, Víctor; Amigo, Ludwig; Zanlungo, Silvana; Galgani, José; Robledo, Fermín; Arrese, Marco; Bozinovic, Francisco; Nervi, Flavio

    2015-01-01

    Background & Aims Bile acids (BAs) regulate energy expenditure by activating G-protein Coupled Bile Acid Receptor Gpbar1/TGR5 by cAMP-dependent mechanisms. Cholecystectomy (XGB) increases BAs recirculation rates resulting in increased tissue exposure to BAs during the light phase of the diurnal cycle in mice. We aimed to determine: 1) the effects of XGB on basal metabolic rate (BMR) and 2) the roles of TGR5 on XGB-dependent changes in BMR. Methods BMR was determined by indirect calorimetry in wild type and Tgr5 deficient (Tgr5-/-) male mice. Bile flow and BAs secretion rates were measured by surgical diversion of biliary duct. Biliary BAs and cholesterol were quantified by enzymatic methods. BAs serum concentration and specific composition was determined by liquid chromatography/tandem mass spectrometry. Gene expression was determined by qPCR analysis. Results XGB increased biliary BAs and cholesterol secretion rates, and elevated serum BAs concentration in wild type and Tgr5-/- mice during the light phase of the diurnal cycle. BMR was ~25% higher in cholecystectomized wild type mice (p <0.02), whereas no changes were detected in cholecystectomized Tgr5-/- mice compared to wild-type animals. Conclusion XGB increases BMR by TGR5-dependent mechanisms in mice. PMID:25738495

  19. 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.

  20. Flexible Sheet-Type Sensor for Noninvasive Measurement of Cellular Oxygen Metabolism on a Culture Dish.

    Directory of Open Access Journals (Sweden)

    Mari Kojima

    Full Text Available A novel flexible sensor was developed for the noninvasive oxygen metabolism measurement of cultivated cells and tissues. This device is composed of a transparent double-layered polymer sheet of ethylene-vinyl alcohol (EVOH and poly(dimethylsiloxane (PDMS having an array of microhole structures of 90 μm diameter and 50 μm depth on its surface. All the microhole structures were equipped with a 1-μm-thick optical chemical sensing layer of platinum porphyrin-fluoropolymer on their bottom. The three-dimensional microstructures of the sensor were fabricated by a newly developed simple and low-cost production method named self-aligned hot embossing. The device was designed to be attached slightly above the cells cultivated on a dish to form a temporarily closed microspace over the target cells during measurement. Since the change in oxygen concentration is relatively fast in the microcompartmentalized culture medium, a rapid evaluation of the oxygen consumption rate is possible by measuring the phosphorescence lifetime of the platinum porphyrin-fluoropolymer. The combined use of the device and an automated optical measurement system enabled the high-throughput sensing of cellular oxygen consumption (100 points/min. We monitored the oxygen metabolism of the human breast cancer cell line MCF7 on a Petri dish and evaluated the oxygen consumption rate to be 0.72 ± 0.12 fmol/min/cell. Furthermore, to demonstrate the utility of the developed sensing system, we demonstrated the mapping of the oxygen consumption rate of rat brain slices and succeeded in visualizing a clear difference among the layer structures of the hippocampus, i.e., the cornu ammonis (CA1 and CA3 and dentate gyrus (DG.

  1. Metabolic Rate and Climatic Fluctuations Shape Continental Wide Pattern of Genetic Divergence and Biodiversity in Fishes

    Science.gov (United States)

    April, Julien; Hanner, Robert H.; Mayden, Richard L.; Bernatchez, Louis

    2013-01-01

    Taxonomically exhaustive and continent wide patterns of genetic divergence within and between species have rarely been described and the underlying evolutionary causes shaping biodiversity distribution remain contentious. Here, we show that geographic patterns of intraspecific and interspecific genetic divergence among nearly all of the North American freshwater fish species (>750 species) support a dual role involving both the late Pliocene-Pleistocene climatic fluctuations and metabolic rate in determining latitudinal gradients of genetic divergence and very likely influencing speciation rates. Results indicate that the recurrent glacial cycles caused global reduction in intraspecific diversity, interspecific genetic divergence, and species richness at higher latitudes. At the opposite, longer geographic isolation, higher metabolic rate increasing substitution rate and possibly the rapid accumulation of genetic incompatibilities, led to an increasing biodiversity towards lower latitudes. This indicates that both intrinsic and extrinsic factors similarly affect micro and macro evolutionary processes shaping global patterns of biodiversity distribution. These results also indicate that factors favouring allopatric speciation are the main drivers underlying the diversification of North American freshwater fishes. PMID:23922969

  2. Aspectos históricos e metodológicos da medição e estimativa da taxa metabólica basal: uma revisão da literatura Historical and methodological aspects of the measurement and prediction of basal metabolic rate: a review

    Directory of Open Access Journals (Sweden)

    Vivian Wahrlich

    2001-08-01

    Full Text Available A taxa metabólica basal (TMB é uma das informações fisiológicas mais importantes em estudos nutricionais clínicos ou epidemiológicos, seja para se determinar as necessidades energéticas ou calcular o gasto energético de indivíduos ou populações. O presente artigo discute, com base numa revisão da literatura, a importância e os aspectos mais relevantes da medição da TMB. Inicialmente, faz-se um histórico do desenvolvimento dos conceitos e da técnica de medição da TMB até os dias atuais. São discutidos os fatores individuais (idade, antropometria, tabagismo, atividade física, dieta, ciclo menstrual e etnia e os possíveis fatores ambientais presentes na hora da medição (temperatura, local e repouso que podem influir no valor da TMB. Apresenta-se as várias equações de predição de TMB disponíveis, em especial a sugerida pela Organização Mundial da Saúde em 1985, e discute-se os estudos realizados desde então, que tentam validar seu uso internacionalmente, particularmente, em populações vivendo nos trópicos. O artigo aponta para a necessidade de se obter mais informações sobre o metabolismo basal nos vários segmentos populacionais vivendo em diferentes regiões do mundo, para que melhores estimativas possam ser fornecidas tanto para o uso clínico quanto epidemiológico.This paper reviews the most relevant aspects of measuring basal metabolic rate (BMR. The authors discuss individual and lifestyle factors (age, anthropometry, smoking, physical activity, diet, menses, and ethnicity as well as possible environmental factors at time of measurement which may alter BMR values. Various available predictive equations, especially those recommended by the World Health Organization in 1985, and subsequent validation studies, particularly in populations living in the tropics, are presented. The review indicates the need for more information on BMR from populations living in different parts of the world so that better

  3. Velocity, aerobic power and metabolic cost of whole body and arms only front crawl swimming at various stroke rates.

    Science.gov (United States)

    Morris, Kirstin S; Osborne, Mark A; Shephard, Megan E; Skinner, Tina L; Jenkins, David G

    2016-05-01

    Stroke rate (SR) has not been considered in previous research examining the relative roles of the limbs in front-crawl performance. This study compared velocity, aerobic power ([Formula: see text]) and metabolic cost (C) between whole body (WB) and arms only (AO) front-crawl swimming across various intensities while controlling SR. Twenty Australian national swimmers performed six 200 m front-crawl efforts under two conditions: (1) WB swimming and, (2) AO swimming. Participants completed the 200 m trials under three SR conditions: "low" (22-26 stroke-cycles min(-1)), "moderate" (30-34 stroke-cycles min(-1) and "high" (38-42 stroke-cycles min(-1)). [Formula: see text] was continuously measured, with C, velocity, SR, and kick rate calculated for each effort. Regardless of the SR condition and sex, AO velocity was consistently lower than WB velocity by ~11.0 % (p  0.01). When C was expressed as a function of velocity, WB and AO regression equations differed for males (p = 0.01) but not for females (p = 0.087). Kick rate increased as SR increased (p swimming is the same. Coaches should consider these results when prescribing AO sets if their intention is to reduce the metabolic load.

  4. Gender dependent rate of metabolism of the opioid receptor-PET ligand [18F]fluoroethyl-diprenorphine

    International Nuclear Information System (INIS)

    Henriksen, G.; Spilker, M.E.; Hauser, A.I.; Boecker, H.; Schwaiger, M.; Wester, H.J.; Sprenger, T.; Platzer, S.; Toelle, T.R.

    2006-01-01

    Aim: The morphinane-derivate 6-O-(2-[ 18 F]fluoroethyl)-6-O-desmethyldiprenorphine ([ 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 [ 18 ]FDPN binding. A study was undertaken to investigate if there are gender dependent differences in the rate of metabolism of [ 18 F]FDPN. Methods: The rate of metabolism of [ 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 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 [ 18 F]FDPN in women than in men. Conclusion: The findings reinforce the need for individualized metabolite correction during [ 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.)

  5. Investigation of (/sup 18/F)2-fluoro-2-deoxyglucose for the measure of myocardial glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.E.; Hoffman, E.J.; Selin, C.; Huang, S.C.; Robinson, G.; MacDonald, N.; Schelbert, H.; Kuhl, D.E.

    1978-12-01

    Fluorine-18-labeled 2-deoxyglucose (FDG) was studied as a glucose analog for the measure of myocardial glucose metabolism. Myocardial uptake and retention, blood clearance, species dependence (dog, monkey, man), and effect of diet on uptake were investigated. Normal myocardial uptake of FDG was 3 to 4% of injected dose in dog and monkey, and 1 to 4% in man, compared with brain uptakes of 1.5 to 3% in dog, 5 to 6% in monkey, and 4 to 8% in man. The myocardial metabolic rate (MR) for glucose in the nonfasting (glycolytic) state was 2.8 times that in the fasting (ketogenic) state. Human subjects showed higher myocardial uptake after a normal meal than after a meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t/sub 1/2/ of 0.2 to 0.3 min, followed by a t/sub 1/2/ of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had half-times of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. With the ECAT positron tomograph, high image-contrast ratios were found between heart and blood (dog 3.5/1, man 14/1), heart and lung (dog 9/1, man 20/1), and heart and liver (dog 15/1, man 10/1). The FDG was taken up rapidly by the myocardium without any significant tissue clearance over a 4-hr period. The FDG exhibited excellent imaging properties. Average counting rates of 12K, 20K, and 40K c/min-mCi injected are obtained in human subjects with high, medium, and low resolutions of the ECAT tomograph. Determination of glucose and FFA MR in vivo with EACT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man.

  6. Investigation of [18F]2-fluoro-2-deoxyglucose for the measure of myocardial glucose metabolism

    International Nuclear Information System (INIS)

    Phelps, M.E.; Hoffman, E.J.; Selin, C.; Huang, S.C.; Robinson, G.; MacDonald, N.; Schelbert, H.; Kuhl, D.E.

    1978-01-01

    Fluorine-18-labeled 2-deoxyglucose (FDG) was studied as a glucose analog for the measure of myocardial glucose metabolism. Myocardial uptake and retention, blood clearance, species dependence (dog, monkey, man), and effect of diet on uptake were investigated. Normal myocardial uptake of FDG was 3 to 4% of injected dose in dog and monkey, and 1 to 4% in man, compared with brain uptakes of 1.5 to 3% in dog, 5 to 6% in monkey, and 4 to 8% in man. The myocardial metabolic rate (MR) for glucose in the nonfasting (glycolytic) state was 2.8 times that in the fasting (ketogenic) state. Human subjects showed higher myocardial uptake after a normal meal than after a meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t/sub 1/2/ of 0.2 to 0.3 min, followed by a t/sub 1/2/ of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had half-times of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. With the ECAT positron tomograph, high image-contrast ratios were found between heart and blood (dog 3.5/1, man 14/1), heart and lung (dog 9/1, man 20/1), and heart and liver (dog 15/1, man 10/1). The FDG was taken up rapidly by the myocardium without any significant tissue clearance over a 4-hr period. The FDG exhibited excellent imaging properties. Average counting rates of 12K, 20K, and 40K c/min-mCi injected are obtained in human subjects with high, medium, and low resolutions of the ECAT tomograph. Determination of glucose and FFA MR in vivo with EACT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man

  7. Fission rate measurements in fuel plate type assembly reactor cores

    International Nuclear Information System (INIS)

    Rogers, J.W.

    1988-01-01

    The methods, materials and equipment have been developed to allow extensive and precise measurement of fission rate distributions in water moderated, U-Al fuel plate assembly type reactor cores. Fission rate monitors are accurately positioned in the reactor core, the reactor is operated at a low power for a short time, the fission rate monitors are counted with detectors incorporating automated sample changers and the measurements are converted to fission rate distributions. These measured fission rate distributions have been successfully used as baseline information related to the operation of test and experimental reactors with respect to fission power and distribution, fuel loading and fission experiments for approximately twenty years at the Idaho National Engineering Laboratory (INEL). 7 refs., 8 figs

  8. Sodium flow rate measurement method of annular linear induction pump

    International Nuclear Information System (INIS)

    Araseki, Hideo

    2011-01-01

    This report describes a method for measuring sodium flow rate of annular linear induction pumps arranged in parallel and its verification result obtained through an experiment and a numerical analysis. In the method, the leaked magnetic field is measured with measuring coils at the stator end on the outlet side and is correlated with the sodium flow rate. The experimental data and the numerical result indicate that the leaked magnetic field at the stator edge keeps almost constant when the sodium flow rate changes and that the leaked magnetic field change arising from the flow rate change is small compared with the overall leaked magnetic field. It is shown that the correlation between the leaked magnetic field and the sodium flow rate is almost linear due to this feature of the leaked magnetic field, which indicates the applicability of the method to small-scale annular linear induction pumps. (author)

  9. Natural stream flow-rates measurements by tracer techniques

    International Nuclear Information System (INIS)

    Cuellar Mansilla, J.

    1982-01-01

    This paper presents the study of the precision obtained measuring the natural stream flow rates by tracer techniques, especially when the system presents a great slope and a bed constituted by large and extended particle size. The experiences were realized in laboratory pilot channels with flow-rates between 15 and 130 [1/s]; and in natural streams with flow-rates from 1 to 25 m 3 /s. Tracer used were In-133m and Br-82 for laboratory and field measurements respectively. In both cases the tracer was injected as a pulse and its dilution measured collecting samples in the measured section, at constant flow-rates, of 5[1] in laboratory experiences and 60[1] of water in field experiences. Precisions obtained at a 95% confidence level were about 2% for laboratory and 3% for field. (I.V.)

  10. 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

    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...

  11. 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.

  12. Differential effects of simple vs. complex carbohydrates on VLDL secretion rates and HDL metabolism in the guinea pig.

    Science.gov (United States)

    Fernandez, M L; Abdel-Fattah, G; McNamara, D J

    1995-04-28

    Guinea pigs were fed isocaloric diets containing 52% (w/w) carbohydrate, either sucrose or starch, to investigate effects of simple vs. complex carbohydrates on plasma VLDL and HDL metabolism. Plasma cholesterol concentrations were not different between dietary groups while plasma triacylglycerol (TAG) and VLDL cholesterol levels were significantly increased in animals fed the sucrose diet (P < 0.05). Hepatic VLDL TAG secretion rates measured following intravenous injection of Triton WR-1339 were not affected by carbohydrate type whereas the rate of apo B secretion was 1.9-fold higher in sucrose fed animals (P < 0.02). Nascent VLDL from the sucrose group contained less TAG per apo B suggesting that the higher plasma TAG in animals fed simple carbohydrates results from increased secretion of VLDL particles with lower TAG content. Sucrose fed animals exhibited higher concentrations of hepatic free cholesterol (P < 0.01) while hepatic TAG levels and acyl CoA:cholesterol acyltransferase (ACAT) activity were not different between groups. Plasma HDL cholesterol concentrations and composition, and plasma lecithin cholesterol acyltransferase (LCAT) activity were not affected by diet yet there was a positive correlation between HDL cholesteryl ester content and LCAT activities (r = 0.70, P < 0.05). Hepatic membranes from the sucrose group had a higher hepatic HDL binding protein number (Bmax) with no changes in the dissociation constant (Kd). These results suggest that at the same carbohydrate energy intake, simple sugars induce modest changes in HDL metabolism while VLDL metabolism is affected at multiple sites, as indicated by the higher concentrations of hepatic cholesterol, dissociation in the synthesis rates of VLDL components, and compositional changes in nascent and mature VLDL.

  13. 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 values. Results from the present study may be used to guide pond culture production of E. carinicauda.

  14. 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.

  15. Absolute rate measurement by light modulation - ESR technique

    Energy Technology Data Exchange (ETDEWEB)

    Choo, K Y; Gaspar, P P

    1977-01-01

    A rate constant is deduced for the reaction of tert-butoxy radicals and trimethylsilane from the measurement of the phase shift between the modulated light source and the ESR signal of trimethylsilyl radical. The rate constant was found to be 3 x 10/sup -2/M/sup -1/. sec/sup -1/ at -50/sup 0/C.

  16. 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.

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

    Science.gov (United States)

    Gingerich, Andrew James; Philipp, David P; Suski, Cory D

    2010-03-01

    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.

  18. 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.

  19. Metabolism

    Science.gov (United States)

    ... lin), which signals cells to increase their anabolic activities. Metabolism is a complicated chemical process, so it's not ... how those enzymes or hormones work. When the metabolism of body chemicals is ... Hyperthyroidism (pronounced: hi-per-THIGH-roy-dih-zum). Hyperthyroidism ...

  20. Metabolic rate and thyroid activity of hens in relation to the state of feathering.

    Science.gov (United States)

    Pietras, M

    1981-01-01

    Heat production, rectal temperature and thyroid activity were determined in NH X Lg hens that were 40 and 80% defeathered. Within individual groups there was a significant increase in heat production only in hens that were 80% defeathered. In comparison with the control group, defeathered chickens had higher metabolic rates during each examined period. During the third week of the experiment there was a temporary drop in the rectal temperature of the experimental birds. After nine weeks chicken with the greatest degree of defeathering had the highest thyroid weight and the highest levels of thyroxin in the blood plasma.

  1. Resting metabolic rate of obese patients under very low calorie ketogenic diet

    OpenAIRE

    Gomez-Arbelaez, Diego; Crujeiras, Ana B.; Castro, Ana I.; Martinez-Olmos, Miguel A.; Canton, Ana; Ordoñez-Mayan, Lucia; Sajoux, Ignacio; Galban, Cristobal; Bellido, Diego; Casanueva, Felipe F.

    2018-01-01

    Background The resting metabolic rate (RMR) decrease, observed after an obesity reduction therapy is a determinant of a short-time weight regain. Thus, the objective of this study was to evaluate changes in RMR, and the associated hormonal alterations in obese patients with a very low-calorie ketogenic (VLCK)-diet induced severe body weight (BW) loss. Method From 20 obese patients who lost 20.2 kg of BW after a 4-months VLCK-diet, blood samples and body composition analysis, determined by DXA...

  2. Evaluation of Specific Metabolic Rates of Major Organs and Tissues: Comparison Between Nonobese and Obese Women

    OpenAIRE

    Wang, ZiMian; Ying, Zhiliang; Bosy-Westphal, Anja; Zhang, Junyi; Heller, Martin; Later, Wiebke; Heymsfield, Steven B.; Müller, Manfred J.

    2011-01-01

    Elia (1992) identified the specific resting metabolic rates (Ki) of major organs and tissues in young adults with normal weight: 200 for liver, 240 for brain, 440 for heart and kidneys, 13 for skeletal muscle, 4.5 for adipose tissue and 12 for residual mass (all units in kcal/kg per day). The aim of the present study was to assess the applicability of Elia’s Ki values for obese adults. A sample of young women (n = 80) was divided into two groups, nonobese (BMI

  3. Measurement of flow rate in the third loop of PWR

    International Nuclear Information System (INIS)

    Gao Shufan.

    1986-01-01

    The range of flow rate was 14000-50000 m 3 /h. The diameter of main tube was 2.6 m. A special made pitot set was placed on the main tube in order to accurately measure the flow rate. A cross slideway and a guide devicc were used to prevent the pitot vibration. Method of equal annular area was used in the measurement. The error was less than 4.2%. A pitot cylinder flowmeter was set also on the main tube to supervise the total flow rate of the third loop

  4. Effect of dietary restriction on immune response of laboratory mice divergently selected for basal metabolic rate.

    Science.gov (United States)

    Książek, Aneta; Konarzewski, Marek

    2012-01-01

    To study whether dietary restriction (DR; 70% of ad lib. feeding)-elicited immunosuppression results from the trade-off between the costs of mounting an immune response and the metabolic costs of maintenance, we subjected mice from two divergent lines selected for high basal metabolic rate (H-BMR) and low BMR (L-BMR) to 4 wk of DR and then challenged them with keyhole limpet hemocyanin (KLH) antigen. Those line types differ genetically with respect to BMR and to the mass of metabolically expensive internal organs, which are larger in H-BMR mice. In mice of both line types, DR resulted in a significant reduction of body mass, an immune response, and the downsizing of spleen, lymph nodes, thymus, heart, and kidneys but not small intestines. DR resulted in a greater reduction of the spleen and lymph nodes in mice of the H-BMR line type, whereas the thymus was more affected in L-BMR line type. In contrast, immunization resulted in an increase of liver mass in DR mice of both line types. A comparison of the results of current and earlier studies on the same mouse line types suggests that metabolic trade-offs involving the costs of an immune response are more apparent when animals are forced to increase energy demands (e.g., by cold exposure) compared to when energy demands are decreased through DR. Our findings also suggest that divelrgent selection on BMR resulted in between-line-type differences in T-cell- and B-cell-mediated types of an immune response. More generally, our results indicate that production of a wide repertoire of antibodies is not correlated with high BMR.

  5. Assessment of salivary flow rate: biologic variation and measure error.

    NARCIS (Netherlands)

    Jongerius, P.H.; Limbeek, J. van; Rotteveel, J.J.

    2004-01-01

    OBJECTIVE: To investigate the applicability of the swab method in the measurement of salivary flow rate in multiple-handicap drooling children. To quantify the measurement error of the procedure and the biologic variation in the population. STUDY DESIGN: Cohort study. METHODS: In a repeated

  6. Ocean acidification alters early successional coral reef communities and their rates of community metabolism.

    Directory of Open Access Journals (Sweden)

    Sam H C Noonan

    Full Text Available Ocean acidification is expected to alter community composition on coral reefs, but its effects on reef community metabolism are poorly understood. Here we document how early successional benthic coral reef communities change in situ along gradients of carbon dioxide (CO2, and the consequences of these changes on rates of community photosynthesis, respiration, and light and dark calcification. Ninety standardised benthic communities were grown on PVC tiles deployed at two shallow-water volcanic CO2 seeps and two adjacent control sites in Papua New Guinea. Along the CO2 gradient, both the upward facing phototrophic and the downward facing cryptic communities changed in their composition. Under ambient CO2, both communities were dominated by calcifying algae, but with increasing CO2 they were gradually replaced by non-calcifying algae (predominantly green filamentous algae, cyanobacteria and macroalgae, which increased from ~30% to ~80% cover. Responses were weaker in the invertebrate communities, however ascidians and tube-forming polychaetes declined with increasing CO2. Differences in the carbonate chemistry explained a far greater amount of change in communities than differences between the two reefs and successional changes from five to 13 months, suggesting community successions are established early and are under strong chemical control. As pH declined from 8.0 to 7.8, rates of gross photosynthesis and dark respiration of the 13-month old reef communities (upper and cryptic surfaces combined significantly increased by 10% and 20%, respectively, in response to altered community composition. As a consequence, net production remained constant. Light and dark calcification rates both gradually declined by 20%, and low or negative daily net calcification rates were observed at an aragonite saturation state of <2.3. The study demonstrates that ocean acidification as predicted for the end of this century will strongly alter reef communities, and

  7. Regional rates of myocardial fatty acid metabolism: Comparison with coronary angiography and ventriculography

    International Nuclear Information System (INIS)

    Schad, N.; Vattimo, A.; Bertelli, P.

    1990-01-01

    In 50 patients, 1 mCi 123 I phenylpentadecanoic acid (IPPA) was injected at peak ergometric stress and 1500 frames were acquired (1 frame/s) with a high count rate gamma camera. Parametric images of rates of decrease and increase for different time intervals after stress were compared with coronary angiography and LV ventriculography, separately evaluating the 3 main coronary territories: 18/150 territories supplied by normal coronaries presented rather homogeneous regional clearing rates, whereas a gradual decrease in clearing rates towards the end of the territory (frequently with peripheral defects) was seen in all 87/150 territories with significant coronary narrowing. In local correspondence to clearing defects, initial IPPA accumulations could be observed with later onset of clearing between 10 and 25 min. In all 44/150 territories presented abnormal clearing rates, mostly with a patchy pattern, with normal coronary anatomy, but all except one had LV dysfunction and a clinical diagnosis of cardiomyopathy, diabetes mellitus or hypertensive disease. Twenty four of the 41 patients with CAD had, in correspondence to a prior myocardial infarction, minimum or missing metabolic activity frequently in circumscribed zones, partly separated by bridges of still viable tissue with preserved but reduced clearing rates. (orig.)

  8. Regional rates of myocardial fatty acid metabolism: comparison with coronary angiography and ventriculography.

    Science.gov (United States)

    Schad, N; Wagner, R K; Hallermeier, J; Daus, H J; Vattimo, A; Bertelli, P

    1990-01-01

    In 50 patients, 1 mCi 123I phenylpentadecanoic acid (IPPA) was injected at peak ergometric stress and 1500 frames were acquired (1 frame/s) with a high count rate gamma camera. Parametric images of rates of decrease and increase for different time intervals after stress were compared with coronary angiography and LV ventriculography, separately evaluating the 3 main coronary territories: 18/150 territories supplied by normal coronaries presented rather homogeneous regional clearing rates, whereas a gradual decrease in clearing rates towards the end of the territory (frequently with peripheral defects) was seen in all 87/150 territories with significant coronary narrowing. In local correspondence to clearing defects, initial IPPA accumulations could be observed with later onset of clearing between 10 and 25 min. 44/150 territories presented abnormal clearing rates, mostly with a patchy pattern, with normal coronary anatomy, but all except one had LV dysfunction and a clinical diagnosis of cardiomyopathy, diabetes mellitus or hypertensive disease. Twenty four of the 41 patients with CAD had, in correspondence to a prior myocardial infarction, minimum or missing metabolic activity frequently in circumscribed zones, partly separated by bridges of still viable tissue with preserved but reduced clearing rates.

  9. QT measurement and heart rate correction during hypoglycemia

    DEFF Research Database (Denmark)

    Christensen, Toke Folke; Randløv, Jette; Christensen, Leif Engmann

    2010-01-01

    induced by intravenous injection of two insulin types in a cross-over design. QT measurements were done using the slope-intersect (SI) and manual annotation (MA) methods. Heart rate correction was done using Bazett's (QTcB) and Fridericia's (QTcF) formulas. Results. The SI method showed significant......Introduction. Several studies show that hypoglycemia causes QT interval prolongation. The aim of this study was to investigate the effect of QT measurement methodology, heart rate correction, and insulin types during hypoglycemia. Methods. Ten adult subjects with type 1 diabetes had hypoglycemia...... prolongation at hypoglycemia for QTcB (42(6) ms; P measuring the QT interval has...

  10. Measuring Outdoor Air Intake Rates into Existing Building

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2009-04-16

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  11. 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.

  12. Cerebral metabolic rates for glucose in mood disorders. Studies with positron emission tomography and fluorodeoxyglucose F 18

    International Nuclear Information System (INIS)

    Baxter, L.R. Jr.; Phelps, M.E.; Mazziotta, J.C.; Schwartz, J.M.; Gerner, R.H.; Selin, C.E.; Sumida, R.M.

    1985-01-01

    Cerebral metabolic rates for glucose were examined in patients with unipolar depression (N = 11), bipolar depression (N = 5), mania (N = 5), bipolar mixed states (N = 3), and in normal controls (N = 9) using positron emission tomography and fluorodeoxyglucose F 18. All subjects were studied supine under ambient room conditions with eyes open. Bipolar depressed and mixed patients had supratentorial whole brain glucose metabolic rates that were significantly lower than those of the other comparison groups. The whole brain metabolic rates for patients with bipolar depression increased going from depression or a mixed state to a euthymic or manic state. Patients with unipolar depression showed a significantly lower ratio of the metabolic rate of the caudate nucleus, divided by that of the hemisphere as a whole, when compared with normal controls and patients with bipolar depression

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Natalie G. Schimpf

    2012-09-01

    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.

  15. Measurement of tritiated norepinephrine metabolism in intact rat brain

    International Nuclear Information System (INIS)

    Levitt, M.; Kowalik, S.; Barkai, A.I.

    1983-01-01

    A procedure for the study of NE metabolism in the intact rat brain is described. The method involves ventriculocisternal perfusion of the adult male rat with artificial CSF containing [ 3 H]NE. Radioactivity in the perfusate associated with NE and its metabolites 3,4-dihydroxymandelic acid (DOMA), 3,4-dihydroxphenylethyleneglycol (DHPG), 3-methoxy-4-hydroxymandelic acid (VMA), 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), and normetanephrine (NMN) is separated using high-performance liquid chromatography (HPLC). After 80 min the radioactivity in the perfusate reaches an apparent steady-state. Analysis of the steady-state samples shows higher activity in the fractions corresponding to DHPG and MHPG than in those corresponding to DOMA and VMA, confirming glycol formation as the major pathway of NE metabolism in rat brain. Pretreatment with an MAO inhibitor (tranylcypromine) results in a marked decrease in the deaminated metabolites DHPG and MHPG and a concurrent increase in NMN. The results indicate this to be a sensitive procedure for the in vivo determination of changes in NE metabolism. (Auth.)

  16. Evolution of basal metabolic rate in bank voles from a multidirectional selection experiment

    Science.gov (United States)

    Sadowska, Edyta T.; Stawski, Clare; Rudolf, Agata; Dheyongera, Geoffrey; Chrząścik, Katarzyna M.; Baliga-Klimczyk, Katarzyna; Koteja, Paweł

    2015-01-01

    A major theme in evolutionary and ecological physiology of terrestrial vertebrates encompasses the factors underlying the evolution of endothermy in birds and mammals and interspecific variation of basal metabolic rate (BMR). Here, we applied the experimental evolution approach and compared BMR in lines of a wild rodent, the bank vole (Myodes glareolus), selected for 11 generations for: high swim-induced aerobic metabolism (A), ability to maintain body mass on a low-quality herbivorous diet (H) and intensity of predatory behaviour towards crickets (P). Four replicate lines were maintained for each of the selection directions and an unselected control (C). In comparison to C lines, A lines achieved a 49% higher maximum rate of oxygen consumption during swimming, H lines lost 1.3 g less mass in the test with low-quality diet and P lines attacked crickets five times more frequently. BMR was significantly higher in A lines than in C or H lines (60.8, 56.6 and 54.4 ml O2 h−1, respectively), and the values were intermediate in P lines (59.0 ml O2 h−1). Results of the selection experiment provide support for the hypothesis of a positive association between BMR and aerobic exercise performance, but not for the association of adaptation to herbivorous diet with either a high or low BMR. PMID:25876844

  17. Water turnover rate and its metabolism in defaunated, refaunated and faunated male buffalo calves

    International Nuclear Information System (INIS)

    Chaudhary, L.C.; Srivastava, Arun

    1993-01-01

    In tropical countries like India, environment climatic conditions are variable throughout the year ranging from favourable to very hostile. The high temperature and humidity and often limited supply of water causes low productivity of livestock even when good quality of feed is supplied in required quantity. The turnover rate of water is related to environmental temperature, feed supply, protein or electrolyte content of the diet and also on physiological status of the animals.In the present experiment tritiated water dilution technique was used in an attempt to study the effect of removing ciliate protozoa from the rumen (defaunation) on water metabolism and its turnover rate in buffalo calves given wheat straw and concentrate mixture. (author). 18 refs., 2 tabs

  18. Cold-hearted bats: uncoupling of heart rate and metabolism during torpor at sub-zero temperatures.

    Science.gov (United States)

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

    2018-01-04

    Many hibernating animals thermoregulate during torpor and defend their body temperature ( T b ) near 0°C by an increase in metabolic rate. Above a critical temperature ( T crit ), animals usually thermoconform. We investigated the physiological responses above and below T crit for a small tree-dwelling bat ( Chalinolobus gouldii , ∼14 g) that is often exposed to sub-zero temperatures during winter. Through simultaneous measurement of heart rate ( f H ) and oxygen consumption ( V̇ O 2 ), 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 ( T a 5-20°C). T crit for this species was at a T a of 0.7±0.4°C, with a corresponding T b of 1.8±1.2°C. Below T crit , animals began to thermoregulate, as indicated by a considerable but disproportionate increase in both f H and V̇ O 2 The maximum increase in f H was only 4-fold greater than the average thermoconforming minimum, compared with a 46-fold increase in V̇ O 2 The differential response of f H and V̇ O 2  to low T a was reflected in a 15-fold increase in oxygen delivery per heart beat (cardiac oxygen pulse). During torpor at low T a , thermoregulating bats maintained a relatively slow f H 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 f H in an unstudied physiological state that may occur frequently in the wild and can be extremely costly for heterothermic animals. © 2018. Published by The Company of Biologists Ltd.

  19. 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...

  20. Accuracy of real time radiography burning rate measurement

    Science.gov (United States)

    Olaniyi, Bisola

    The design of a solid propellant rocket motor requires the determination of a propellant's burning-rate and its dependency upon environmental parameters. The requirement that the burning-rate be physically measured, establishes the need for methods and equipment to obtain such data. A literature review reveals that no measurement has provided the desired burning rate accuracy. In the current study, flash x-ray modeling and digitized film-density data were employed to predict motor-port area to length ratio. The pre-fired port-areas and base burning rate were within 2.5% and 1.2% of their known values, respectively. To verify the accuracy of the method, a continuous x-ray and a solid propellant rocket motor model (Plexiglas cylinder) were used. The solid propellant motor model was translated laterally through a real-time radiography system at different speeds simulating different burning rates. X-ray images were captured and the burning-rate was then determined. The measured burning rate was within 1.65% of the known values.

  1. 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

  2. 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

  3. Methods of measuring metabolism during surgery in humans: focus on the liver-brain relationship.

    Science.gov (United States)

    Battezzati, Alberto; Bertoli, Simona

    2004-09-01

    The purpose of this work is to review recent advances in setting methods and models for measuring metabolism during surgery in humans. Surgery, especially solid organ transplantation, may offer unique experimental models in which it is ethically acceptable to gain information on difficult problems of amino acid and protein metabolism. Two areas are reviewed: the metabolic study of the anhepatic phase during liver transplantation and brain microdialysis during cerebral surgery. The first model offers an innovative approach to understand the relative role of liver and extrahepatic organs in gluconeogenesis, and to evaluate whether other organs can perform functions believed to be exclusively or almost exclusively performed by the liver. The second model offers an insight to intracerebral metabolism that is closely bound to that of the liver. The recent advances in metabolic research during surgery provide knowledge immediately useful for perioperative patient management and for a better control of surgical stress. The studies during the anhepatic phase of liver transplantation have showed that gluconeogenesis and glutamine metabolism are very active processes outside the liver. One of the critical organs for extrahepatic glutamine metabolism is the brain. Microdialysis studies helped to prove that in humans there is an intense trafficking of glutamine, glutamate and alanine among neurons and astrocytes. This delicate network is influenced by systemic amino acid metabolism. The metabolic dialogue between the liver and the brain is beginning to be understood in this light in order to explain the metabolic events of brain damage during liver failure.

  4. Validating a new device for measuring tear evaporation rates.

    Science.gov (United States)

    Rohit, Athira; Ehrmann, Klaus; Naduvilath, Thomas; Willcox, Mark; Stapleton, Fiona

    2014-01-01

    To calibrate and validate a commercially available dermatology instrument to measure tear evaporation rate of contact lens wearers. A dermatology instrument was modified by attaching a swim goggle cup such that the cup sealed around the eye socket. Results for the unmodified instrument are dependent on probe area and enclosed volume. Calibration curves were established using a model eye, to account for individual variations in chamber volume and exposed area. Fifteen participants were recruited and the study included a contact lens wear and a no contact lens wear stage. Day and diurnal variation of the measurements were assessed by taking the measurement three times a day over 2 days. The coefficient of repeatability of the measurement was calculated and a linear mixed model assessed the influence of humidity, temperature, contact lens wear, day and diurnal variations on tear evaporation rate. The associations between variables were assessed using Pearson correlation coefficient. Absolute evaporation rates with and without contact lens wear were calculated based on the new calibration. The measurements were most repeatable during the evening with no lens wear (COR = 49 g m⁻² h) and least repeatable during the evening with contact lens wear (COR = 93 g m⁻² h). Humidity (p = 0.007), and contact lens wear (p evaporation rate. However, temperature (p = 0.54) diurnal variation (p = 0.85) and different days (p = 0.65) had no significant effect after controlling for humidity. Tear evaporation rates can be measured using a modified dermatology instrument. Measurements were higher and more variable with lens wear consistent with previous literature. Control of environmental conditions is important as a higher humidity results in a reduced evaporation rate. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  5. Omega-3 Fatty Acid Supplementation for 12 Weeks Increases Resting and Exercise Metabolic Rate in Healthy Community-Dwelling Older Females.

    Directory of Open Access Journals (Sweden)

    Samantha L Logan

    Full Text Available Critical among the changes that occur with aging are decreases in muscle mass and metabolic rate and an increase in fat mass. These changes may predispose older adults to chronic disease and functional impairment; ultimately resulting in a decrease in the quality of life. Research has suggested that long chain omega-3 fatty acids, found predominantly in fatty fish, may assist in reducing these changes. The objective of this study was to evaluate the effect of fish oil (FO supplementation in a cohort of healthy, community-dwelling older females on 1 metabolic rate and substrate oxidation at rest and during exercise; 2 resting blood pressure and resting and exercise heart rates; 3 body composition; 4 strength and physical function, and; 5 blood measures of insulin, glucose, c-reactive protein, and triglycerides. Twenty-four females (66 ± 1 yr were recruited and randomly assigned to receive either 3g/d of EPA and DHA or a placebo (PL, olive oil for 12 wk. Exercise measurements were taken before and after 12 wk of supplementation and resting metabolic measures were made before and at 6 and 12 wk of supplementation. The results demonstrated that FO supplementation significantly increased resting metabolic rate by 14%, energy expenditure during exercise by 10%, and the rate of fat oxidation during rest by 19% and during exercise by 27%. In addition, FO consumption lowered triglyceride levels by 29% and increased lean mass by 4% and functional capacity by 7%, while no changes occurred in the PL group. In conclusion, FO may be a strategy to improve age-related physical and metabolic changes in healthy older females. Trial registration: ClinicalTrials.gov NCT01734538.

  6. Consequences of Fatherhood in the Biparental California Mouse (Peromyscus californicus): Locomotor Performance, Metabolic Rate, and Organ Masses.

    Science.gov (United States)

    Andrew, Jacob R; Saltzman, Wendy; Chappell, Mark A; Garland, Theodore

    2016-01-01

    Although effects of motherhood on mothers have been well documented in mammals, the effects of fatherhood on fathers are not well known. We evaluated effects of being a father on key metabolic and performance measures in the California mouse, Peromyscus californicus. California mice are genetically monogamous in the wild, and fathers show similar parental behavior to mothers, with the exception of lactation. To investigate the impact of fatherhood on fathers, focal males were paired with an intact female (breeding males), a tubally ligated female (nonbreeding males), or another male (virgins). Starting 3-5 d after the birth of each breeding pair's first litter, males were tested for locomotor performance (maximum sprint speed, treadmill endurance), basal metabolic rate (BMR), and maximum oxygen consumption ([Formula: see text]). At the end of the 11-d test period, mice were euthanized, hematocrit was determined, and organs were weighed. Speed, endurance, and [Formula: see text] were significantly repeatable between two replicate measurement days but did not differ among groups, nor did BMR. Breeding males had significantly larger hind limb muscles than did nonbreeding males, whereas virgin males had heavier subcutaneous fat pads than did nonbreeding and breeding males. Several correlations were observed at the level of individual variation (residuals from ANCOVA models), including positive correlations for endurance with [Formula: see text], [Formula: see text] with testes mass, and some of the digestion-related organs with each other. These results indicate that fatherhood may not have pronounced performance, metabolic, or morphological effects on fathers, at least under standard laboratory conditions and across a single breeding cycle.

  7. Measurement of viscosity of slush at high shear rates

    OpenAIRE

    小林, 俊一; 川村, 公之; 津川, 圭一; 和泉, 薫; Kobayashi, Shun'ichi; Kawamura, Kimiyuki; Tugawa, Keiichi; Izumi, Kaoru

    1988-01-01

    Measurements of viscosity of slush were carried out using a method of flow along an inclined smooth surface in a 0℃cold room. The method was used to get the values of viscosity under high shear rates (25 and 75s^). From our experiments two important results were obtained: 1) the viscosity of slush decreases with increasing shear rates; 2) The fluid behavior is pseudoplastic that the values of non-Newtonian index of viscosity were less than unity.

  8. Seasonal rates of benthic primary production in a Greenland fjord measured by aquatic eddy correlation

    DEFF Research Database (Denmark)

    M. Attard, Karl; Glud, Ronnie; McGinnis, Daniel F.

    2014-01-01

    -quality multiple-day EC data sets document the presence of a year-round productive benthic phototrophic community. The shallow-water sites were on average autotrophic during the spring and summer months, up to 43.6 mmol O2 m22 d21, and heterotrophic or close to metabolic balance during the autumn and winter....... Substantial benthic gross primary production (GPP) was measured year-round. The highest GPP rates were measured during the spring, up to 5.7 mmol O2 m22 h21 (136.8 mmol O2 m22 d21), and even at low light levels (, 80 mmol quanta m22 s21) during late autumn and winter we measured rates of up to 1.8 mmol O2 m22...

  9. Development of nondestructive measurement of cold work rate, (2)

    International Nuclear Information System (INIS)

    Kamimura, Hideaki; Igarashi, Miyuki; Satoh, Masakazu; Miura, Makoto

    1978-01-01

    Cold-worked type 316 stainless steel will be used as fuel cladding material for the proto-type fast reactor MONJU. Cold work rate is an important parameter in swelling behavior of fuel cladding. It has been shown that austenitic stainless steel undergoes martensitic transformation during cold working. Nondestructive evaluation of cold work rate will be expected by measuring residual magnetism produced in the presence of martensitic phase when cold worked austenitic stainless steel is magnetized. In the previous work, the residual magnetism of cladding tubes of type 316 stainless steel was measured. The results have shown high degree of the correlation between residual magnetism and cold work rate. This paper reports the results of measurement on cold-rolled type 316 stainless steel plate samples. Dimensions of the specimens are 100 mm long and 3.5 and 7 mm wide. The apparatus and experimental procedures were similar to the previous work. Good agreement was found between the estimated cold work rate obtained in the previous work and that for cold rolled plate specimens. Measurement of residual magnetism in identical direction with magnetization showed smaller dispersion of data as compared with that in transverse direction. The residual magnetism near specimen surface hardly decreased when the surface of specimen was chemically removed. The reason for the comparative decrease in residual magnetism at 10% and 15% cold work rate is not clear. (Wakatsuki, Y.)

  10. Estimating average glandular dose by measuring glandular rate in mammograms

    International Nuclear Information System (INIS)

    Goto, Sachiko; Azuma, Yoshiharu; Sumimoto, Tetsuhiro; Eiho, Shigeru

    2003-01-01

    The glandular rate of the breast was objectively measured in order to calculate individual patient exposure dose (average glandular dose) in mammography. By employing image processing techniques and breast-equivalent phantoms with various glandular rate values, a conversion curve for pixel value to glandular rate can be determined by a neural network. Accordingly, the pixel values in clinical mammograms can be converted to the glandular rate value for each pixel. The individual average glandular dose can therefore be calculated using the individual glandular rates on the basis of the dosimetry method employed for quality control in mammography. In the present study, a data set of 100 craniocaudal mammograms from 50 patients was used to evaluate our method. The average glandular rate and average glandular dose of the data set were 41.2% and 1.79 mGy, respectively. The error in calculating the individual glandular rate can be estimated to be less than ±3%. When the calculation error of the glandular rate is taken into consideration, the error in the individual average glandular dose can be estimated to be 13% or less. We feel that our method for determining the glandular rate from mammograms is useful for minimizing subjectivity in the evaluation of patient breast composition. (author)

  11. Rapid Measurement of Neutron Dose Rate for Transport Index

    International Nuclear Information System (INIS)

    Morris, R.L.

    2000-01-01

    A newly available neutron dose equivalent remmeter with improved sensitivity and energy response has been put into service at Rocky Flats Environmental Technology Site (RFETS). This instrument is being used to expedite measurement of the Transport Index and as an ALARA tool to identify locations where slightly elevated neutron dose equivalent rates exist. The meter is capable of measuring dose rates as low as 0.2 μSv per hour (20 μrem per hour). Tests of the angular response and energy response of the instrument are reported. Calculations of the theoretical instrument response made using MCNPtrademark are reported for materials typical of those being shipped

  12. Three-dimensional spatial imaging in multiphoton ionization rate measurements

    International Nuclear Information System (INIS)

    Bredy, Richard; Camp, Howard A.; Nguyen, Hai; Awata, Takaaki; Shan Bing; Chang Zhenghu; DePaola, B.D.

    2004-01-01

    An experiment is described in which an apparatus is used to demonstrate the feasibility of measuring multiphoton photoionization rates in the interaction of short pulsed lasers with atoms or molecules. With this methodology, the ionization rate is measured as a function of the spatial position in the beam-waist region of the laser through the direct three-dimensional spatial imaging of the ionization events. Thus, if the spatial dependence of the laser beam intensity were known, a series of experiments could yield the intensity dependence of multiphoton ionization without the assumptions or errors that are generally inherent in the integration over one or more dimensions in the laser focal volume

  13. Measurement of thoron exhalation rates from building materials.

    Science.gov (United States)

    de With, G; de Jong, P; Röttger, A

    2014-09-01

    Thoron (220Rn) exhalation from building materials has become increasingly recognized as a potential source for radiation exposure in dwellings. However, contrary to radon (220Rn), limited information on thoron exposure is available. The purpose of this study is to develop a test method for the determination of the thoron exhalation rate from building materials. The method is validated, and subsequently the thoron exhalation rates from 10 widely-applied concretes, gypsums, brick, limestone, and mortar are determined. The measured thoron exhalation rates of these materials range from 0.01 Bq m-2 s-1 to 0.43 Bq m-2 s-1, with relative standard uncertainties between 6% to 14%.

  14. Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

    Directory of Open Access Journals (Sweden)

    Fabio A. Labra

    2016-10-01

    Full Text Available Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2, in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA, finding that r(VO2 fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s, either monofractal or weak multifractal dynamics are observed depending on whether Ta  15 °C respectively. For larger time scales, r(VO2 fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q, showing that the infinite number of exponents h(q can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2 time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

  15. Improved growth rate in Clostridium thermocellum hydrogenase mutant via perturbed sulfur metabolism.

    Science.gov (United States)

    Biswas, Ranjita; Wilson, Charlotte M; Giannone, Richard J; Klingeman, Dawn M; Rydzak, Thomas; Shah, Manesh B; Hettich, Robert L; Brown, Steven D; Guss, Adam M

    2017-01-01

    Metabolic engineering is a commonly used approach to develop organisms for an industrial function, but engineering aimed at improving one phenotype can negatively impact other phenotypes. This lack of robustness can prove problematic. Cellulolytic bacterium Clostridium thermocellum is able to rapidly ferment cellulose to ethanol and other products. Recently, genes involved in H 2 production, including the hydrogenase maturase hydG and NiFe hydrogenase ech , were deleted from the chromosome of C. thermocellum . While ethanol yield increased, the growth rate of Δ hydG decreased substantially compared to wild type. Addition of 5 mM acetate to the growth medium improved the growth rate in C. thermocellum ∆hydG , whereas wild type remained unaffected. Transcriptomic analysis of the wild type showed essentially no response to the addition of acetate. However, in C. thermocellum ΔhydG , 204 and 56 genes were significantly differentially regulated relative to wild type in the absence and presence of acetate, respectively. Genes, Clo1313_0108-0125, which are predicted to encode a sulfate transport system and sulfate assimilatory pathway, were drastically upregulated in C. thermocellum ΔhydG in the presence of added acetate. A similar pattern was seen with proteomics. Further physiological characterization demonstrated an increase in sulfide synthesis and elimination of cysteine consumption in C. thermocellum ΔhydG . Clostridium thermocellum ΔhydGΔech had a higher growth rate than ΔhydG in the absence of added acetate, and a similar but less pronounced transcriptional and physiological effect was seen in this strain upon addition of acetate. Sulfur metabolism is perturbed in C. thermocellum ΔhydG strains, likely to increase flux through sulfate reduction to act either as an electron sink to balance redox reactions or to offset an unknown deficiency in sulfur assimilation.

  16. Flow Rate Measurement in Multiphase Flow Rig: Radiotracer and Conventional

    International Nuclear Information System (INIS)

    Nazrul Hizam Yusoff; Noraishah Othman; Nurliyana Abdullah; Amirul Syafiq Mohd Yunos; Rasif Mohd Zain; Roslan Yahya

    2015-01-01

    Applications of radiotracer technology are prevalent throughout oil refineries worldwide, and this industry is one of the main users and beneficiaries of the technology. Radioactive tracers have been used to a great extent in many applications i.e. flow rate measurement, RTD, plant integrity evaluation and enhancing oil production in oil fields. Chemical and petrochemical plants are generally continuously operating and technically complex where the radiotracer techniques are very competitive and largely applied for troubleshooting inspection and process analysis. Flow rate measurement is a typical application of radiotracers. For flow measurements, tracer data are important, rather than the RTD models. Research is going on in refining the existing methods for single phase flow measurement, and in developing new methods for multiphase flow without sampling. The tracer techniques for single phase flow measurements are recognized as ISO standards. This paper presents technical aspect of laboratory experiments, which have been carried out using Molybdenum-99 - Mo99 (radiotracer) to study and determine the flow rate of liquid in multiphase flow rig. The multiphase flow rig consists of 58.7 m long and 20 cm diameter pipeline that can accommodate about 0.296 m 3 of liquid. Tap water was used as liquid flow in pipeline and conventional flow meters were also installed at the flow rig. The flow rate results; radiotracer and conventional flow meter were compared. The total count method was applied for radiotracer technique and showed the comparable results with conventional flow meter. (author)

  17. Correlation measurements of sodium flow rate with magnetic sensors

    International Nuclear Information System (INIS)

    Kebadze, B.V.; Krasnoyarov, N.V.; Adamovskij, L.A.; Golushko, V.V.; Sroelov, V.S.

    1978-01-01

    The results of bench-mark experiments and those carried out at the BOR-60 reactor to measure the sodium coolant flow rate by a correlation method are presented. The method is based on detecting the eddy type flow hydraulic nonuniformities using magnetic flowmeters. The measurements were fulfilled in a broad range of flow rates (G=10-10 4 m 3 /h, Re=2x10 5 -2x10 7 ). The measured and calculated mutual correlation functions are presented with parallel and perpendicular orientations of the flowmeters magnetic fields. A good accord is stated. Prerequirements to the arrangement of the measuring systems are formulated. As an important advantage of the correlation method a possibility of the flowmeter calibration in situ is hydhlighted

  18. 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

  19. Metabolic rate, evaporative water loss and thermoregulatory state in four species of bats in the Negev desert.

    Science.gov (United States)

    Muñoz-Garcia, Agustí; Larraín, Paloma; Ben-Hamo, Miriam; Cruz-Neto, Ariovaldo; Williams, Joseph B; Pinshow, Berry; Korine, Carmi

    2016-01-01

    Life in deserts is challenging for bats because of their relatively high energy and water requirements; nevertheless bats thrive in desert environments. We postulated that bats from desert environments have lower metabolic rates (MR) and total evaporative water loss (TEWL) than their mesic counterparts. To test this idea, we measured MR and TEWL of four species of bats, which inhabit the Negev desert in Israel, one species mainly restricted to hyper-arid deserts (Otonycteris hemprichii), two species from semi-desert areas (Eptesicus bottae and Plecotus christii), and one widespread species (Pipistrellus kuhlii). We also measured separately, in the same individuals, the two components of TEWL, respiratory water loss (RWL) and cutaneous evaporative water loss (CEWL), using a mask. In all the species, MR and TEWL were significantly reduced during torpor, the latter being a consequence of reductions in both RWL and CEWL. Then, we evaluated whether MR and TEWL in bats differ according to their geographic distributions, and whether those rates change with Ta and the use of torpor. We did not find significant differences in MR among species, but we found that TEWL was lowest in the species restricted to desert habitats, intermediate in the semi-desert dwelling species, and highest in the widespread species, perhaps a consequence of adaptation to life in deserts. Our results were supported by a subsequent analysis of data collected from the literature on rates of TEWL for 35 bat species from desert and mesic habitats. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Measurement of droplet vaporization rate enhancement caused by acoustic disturbances

    Science.gov (United States)

    Anderson, T. J.; Winter, M.

    1992-10-01

    Advanced laser diagnostics are being applied to quantify droplet vaporization enhancement in the presence of acoustic fields which can lead to instability in liquid-fueled rockets. While models have been developed to describe the interactions between subcritical droplet vaporization and acoustic fields in the surrounding gases, they have not been verified experimentally. In the super critical environment of a rocket engine combustor, little is understood about how the injected fluid is distributed. Experiments in these areas have been limited because of the lack of diagnostic techniques capable of providing quantitative results. Recently, however, extremely accurate vaporization rate measurements have been performed on droplets in a subcritical environment using morphology-dependent resonances (MDR's) in which fluorescence from an individual droplet provides information about its diameter. Initial measurements on methanol droplets behind a pressure pulse with a pressure ratio of 1.2 indicated that the evaporation rate in the first few microsec after wave passage was extremely high. Subsequent measurements have been made to validate these results using MDR's acquired from similarly-sized droplets using a pulse with a 1.1 pressure ratio. A baseline measurement was also made using a non evaporative fluid under similar Weber and Reynolds number conditions. The MDR technique employed for these measurements is explained and the facilities are described. The evaporation measurement results are shown and the rates observed from different droplet materials and different wave strengths are compared.

  1. Effects of salinity on metabolic rate and branchial expression of genes involved in ion transport and metabolism in Mozambique tilapia (Oreochromis mossambicus).

    Science.gov (United States)

    Zikos, Aris; Seale, Andre P; Lerner, Darren T; Grau, E Gordon; Korsmeyer, Keith E

    2014-12-01

    This study investigated the effects of two rearing salinities, and acute salinity transfer, on the energetic costs of osmoregulation and the expression of metabolic and osmoregulatory genes in the gill of Mozambique tilapia. Using automated, intermittent-flow respirometry, measured standard metabolic rates (SMRs) of tilapia reared in seawater (SW, 130 mg O₂ kg⁻¹ h⁻¹) were greater than those reared in fresh water (FW, 103 mg O₂ kg⁻¹ h⁻¹), when normalized to a common mass of 0.05 kg and at 25±1°C. Transfer from FW to 75% SW increased SMR within 18h, to levels similar to SW-reared fish, while transfer from SW to FW decreased SMR to levels similar to FW-reared fish. Branchial gene expression of Na⁺-K⁺-2Cl⁻ cotransporter (NKCC), an indicator of SW-type mitochondria-rich (MR) cells, was positively correlated with SMR, while Na⁺-Cl⁻ cotransporter (NCC), an indicator of FW-type MR cells, was negatively correlated. Principal Components Analysis also revealed that branchial expression of cytochrome c oxidase subunit IV (COX-IV), glycogen phosphorylase (GP), and a putative mitochondrial biogenesis regulator in fish, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), were correlated with a higher SMR, plasma osmolality, and environmental salinity, while expression of glycogen synthase (GS), PGC-1β, and nuclear respiratory factor 1 (NRF-1) had negative correlations. These results suggest that the energetic costs of osmoregulation are higher in SW than in FW, which may be related to the salinity-dependent differences in osmoregulatory mechanisms found in the gills of Mozambique tilapia. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Endothelial dysfunction and reduced heart rate variability in patients with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Elena Nikolaevna Smirnova

    2018-03-01

    Full Text Available According to experts of the World Health Organization (WHO, metabolic syndrome (MS can be considered as pandemy of the XXI century, because its prevalence among the population of developed countries is about 25-35%. In this study with the purpose of complex investigation of the autonomic nervous system and endothelial function we included 66 patients with MS between the ages of 25 and 61 (46.9±9.9 years. A comparison group of apparently healthy individuals (16 individuals, average age of 45.3±2.3 years; P>0.05 was studied. To evaluate the response of microvascular tone, we used the method of wavelet analysis of skin temperature oscillations during cooling of the limb. All patients underwent the study of heart rate variability. The levels of insulin, endothelin-1, and vascular endothelial growth factor were determined using enzyme immunoassay. Patients with MS had significant differences in all metabolic parameters. Our study showed that in the group of MS there is a decrease of the variability of heart rhythm compared with the healthy group. Conducting cold test revealed signs of endothelial dysfunction in the MS group, which was manifested by the decrease of the index of vasodilation in the endothelial and neurogenic frequency range. In the study group we determined the increase in biochemical markers of endothelial dysfunction, which correlated with parameters of vasodilation. Also, the presence of endothelial dysfunction significantly correlated with signs of reduction of the variability of the heart rhythm.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    John E. Blundell

    2012-09-01

    Full Text Available 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.

  5. Increased Rate of NAD Metabolism Shortens Plant Longevity by Accelerating Developmental Senescence in Arabidopsis.

    Science.gov (United States)

    Hashida, Shin-Nosuke; Itami, Taketo; Takahara, Kentaro; Hirabayashi, Takayuki; Uchimiya, Hirofumi; Kawai-Yamada, Maki

    2016-11-01

    NAD is a well-known co-enzyme that mediates hundreds of redox reactions and is the basis of various processes regulating cell responses to different environmental and developmental cues. The regulatory mechanism that determines the amount of cellular NAD and the rate of NAD metabolism remains unclear. We created Arabidopsis thaliana plants overexpressing the NAD synthase (NADS) gene that participates in the final step of NAD biosynthesis. NADS overexpression enhanced the activity of NAD biosynthesis but not the amounts of NAD + , NADH, NADP + or NADPH. However, the amounts of some intermediates were elevated, suggesting that NAD metabolism increased. The NAD redox state was greatly facilitated by an imbalance between NAD generation and degradation in response to bolting. Metabolite profiling and transcriptional analysis revealed that the drastic modulation of NAD redox homeostasis increased tricarboxylic acid flux, causing the ectopic generation of reactive oxygen species. Vascular bundles suffered from oxidative stress, leading to a malfunction in amino acid and organic acid transportation that caused early wilting of the flower stalk and shortened plant longevity, probably due to malnutrition. We concluded that the mechanism regulating the balance between NAD synthesis and degradation is important in the systemic plant response to developmental cues during the growth-phase transition. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  6. Influence of a Gas Exchange Correction Procedure on Resting Metabolic Rate and Respiratory Quotient in Humans.

    Science.gov (United States)

    Galgani, Jose E; Castro-Sepulveda, Mauricio A

    2017-11-01

    The aim of this study was to determine the influence of a gas exchange correction protocol on resting metabolic rate (RMR) and respiratory quotient (RQ), assessed by a Vmax Encore 29n metabolic cart (SensorMedics Co., Yorba Linda, California) in overnight fasted and fed humans, and to assess the predictive power of body size for corrected and uncorrected RMR. Healthy participants (23 M/29 F; 34 ± 9 years old; 26.3 ± 3.7 kg/m 2 ) ingested two 3-hour-apart glucose loads (75 g). Indirect calorimetry was conducted before and hourly over a 6-hour period. Immediately after indirect calorimetry assessment, gas exchange was simulated through high-precision mass-flow regulators, which permitted the correction of RMR and RQ values. Uncorrected and corrected RMR and RQ were directly related at each time over the 6-hour period. However, uncorrected versus corrected RMR was 6.9% ± 0.5% higher (128 ± 7 kcal/d; P exchange in humans over a 6-hour period is feasible and provides information of improved accuracy. © 2017 The Obesity Society.

  7. The choice of label and measurement technique in tracer studies of body protein metabolism in man

    International Nuclear Information System (INIS)

    James, W.P.T.; Sender, P.M.; Garlick, P.J.; Waterlow, J.C.

    1975-01-01

    The turnover of non-serum proteins in man has had limited study despite the physiological importance of maintaining the balance between synthesis and breakdown of body proteins. Body protein is usually considered as a single pool and breakdown rates are often measured by monitoring excreted label at intervals after pulse labelling with radioactive or 15 N amino acids. No label has yet been used for measuring tissue protein breakdown in man which is free from the major problem of label re-utilization. All measurements of breakdown rates, eg. with 75 Se-selenomethionine, 15 N- or 14 C-glycine, give rate constants which are too low. The heterogeneity of body proteins also means that an estimate of the weighted average breakdown rate can only be obtained after following the excretion of isotope for a long period, perhaps of the order of 3-4 half-lives which, for man, would be 100 days after labelling. We therefore use infusions with either 14 C- or 15 N-labelled amino acids to measure breakdown and synthesis rates: these values are less affected by problems of protein heterogeneity. Single injection techniques are subject to more error than constant infusions of label because of the difficulty of defining the precursor activity. 15 N labelling need not be confined to essential amino acids if total protein rather than amino acid turnover is studied: the latter involves measurements of the labelled amino acid itself which is difficult with 15 N because of the small amounts of free amino acid nitrogen available. Carbon labelling of non-essential amino acids is unsuitable for studies of protein turnover and the choice of the position of the label on the molecule is important when labelled essential amino acids are employed. Short-term changes in protein metabolism are evaluated better with amino acids with a small pool size; the equilibration time in the excretory bicarbonate pool is also shorter than in the urea pool so that 15 N is less useful than carbon labelling. We

  8. Measurement of rates of cholesterol synthesis using tritiated water

    International Nuclear Information System (INIS)

    Dietschy, J.M.; Spady, D.K.

    1984-01-01

    Rates of sterol synthesis in various tissues commonly are assessed by assaying levels of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase on isolated microsomes or by measuring the rates of incorporation of various 14 C-labeled substrates or [ 3 H]water into cholesterol by whole cell preparations in vitro or by the tissues of the whole animal in vivo. While measurement of activities of HMG-CoA reductase or rates of incorporation of 14 C-labeled substrates into cholesterol give useful relative rates of sterol production, neither method yields absolute rates of cholesterol synthesis. The use of [ 3 H]water circumvents the problem of variable and unknown dilution of the specific activity of the precursor pool encountered when 14 C-labeled substrates are used and does yield absolute rates of cholesterol synthesis provided that the 3 H/C incorporation ratio is known for a particular tissue. In 12 different experimental situations it has been found that from 21 to 27 micrograms atoms of 3 H are incorporated into cholesterol from [ 3 H]water in different tissues of several animal species, so that the 3 H/C incorporation ratio is similar under nearly all experimental conditions and varies from 0.78 to 1.00. When administered in vivo, [ 3 H]water rapidly equilibrates with intracellular water and is incorporated into sterols within the various organs at rates that are linear with respect to time. From such data it is possible to obtain absolute rates of cholesterol synthesis in the whole animal and in the various organs of the animal. Current data suggest, therefore, that use of [ 3 H]water yields the most accurate rates of cholesterol synthesis both in vitro and in vivo

  9. Heart rate measurement based on face video sequence

    Science.gov (United States)

    Xu, Fang; Zhou, Qin-Wu; Wu, Peng; Chen, Xing; Yang, Xiaofeng; Yan, Hong-jian

    2015-03-01

    This paper proposes a new non-contact heart rate measurement method based on photoplethysmography (PPG) theory. With this method we can measure heart rate remotely with a camera and ambient light. We collected video sequences of subjects, and detected remote PPG signals through video sequences. Remote PPG signals were analyzed with two methods, Blind Source Separation Technology (BSST) and Cross Spectral Power Technology (CSPT). BSST is a commonly used method, and CSPT is used for the first time in the study of remote PPG signals in this paper. Both of the methods can acquire heart rate, but compared with BSST, CSPT has clearer physical meaning, and the computational complexity of CSPT is lower than that of BSST. Our work shows that heart rates detected by CSPT method have good consistency with the heart rates measured by a finger clip oximeter. With good accuracy and low computational complexity, the CSPT method has a good prospect for the application in the field of home medical devices and mobile health devices.

  10. Sodium flow rate measurement method of annular linear induction pumps

    International Nuclear Information System (INIS)

    Araseki, Hideo; Kirillov, Igor R.; Preslitsky, Gennady V.

    2012-01-01

    Highlights: ► We found a new method of flow rate monitoring of electromagnetic pump. ► The method is very simple and does not require a large space. ► The method was verified with an experiment and a numerical analysis. ► The experimental data and the numerical results are in good agreement. - Abstract: The present paper proposes a method for measuring sodium flow rate of annular linear induction pumps. The feature of the method lies in measuring the leaked magnetic field with measuring coils near the stator end on the outlet side and in correlating it with the sodium flow rate. This method is verified through an experiment and a numerical analysis. The data obtained in the experiment reveals that the correlation between the leaked magnetic field and the sodium flow rate is almost linear. The result of the numerical analysis agrees with the experimental data. The present method will be particularly effective to sodium flow rate monitoring of each one of plural annular linear induction pumps arranged in parallel in a vessel which forms a large-scale pump unit.

  11. Inter-Observer Agreement in Measuring Respiratory Rate

    DEFF Research Database (Denmark)

    Nielsen, Louise Gramstrup; Folkestad, Lars; Brodersen, Jacob Broder

    2015-01-01

    BACKGROUND: Respiratory rate (RR) is an important vital sign which is strongly correlated with in-hospital mortality. At the same time, RR is the most likely vital sign to be omitted when assessing a patient. We believe that one reason for this could be the difficulty in measure the RR, since...

  12. High-temperature rate constant measurements for OH+xylenes

    KAUST Repository

    Elwardani, Ahmed Elsaid; Badra, Jihad; Farooq, Aamir

    2015-01-01

    The overall rate constants for the reactions of hydroxyl (OH) radicals with o-xylene (k 1), m-xylene (k 2), and p-xylene (k 3) were measured behind reflected shock waves over 890-1406K at pressures of 1.3-1.8atm using OH laser absorption near 306

  13. Intercalibration of mussel Mytilus edulis clearance rate measurements

    NARCIS (Netherlands)

    Kjerulf Petersen, J.; Bougrier, S.; Smaal, A.C.; Garen, P.; Robert, S.; Larsen, J.E.N.; Brummelhuis, E.B.M.

    2004-01-01

    Clearance rate (CR) was measured in blue mussels Mytilus edulis L. from Aiguillon Bay and the Oosterschelde using 3 different methods: the flow-through method, the bio-deposition method and the indirect or clearance method. CR differed significantly as a function of the method used and of the origin

  14. Multi-omics approach to study the growth efficiency and amino acid metabolism in Lactococcus lactis at various specific growth rates

    Directory of Open Access Journals (Sweden)

    Arike Liisa

    2011-02-01

    Full Text Available Abstract Background Lactococcus lactis is recognised as a safe (GRAS microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth. Results Using glucose limited continuous cultivations, specific growth rate dependent metabolism of L. lactis including utilization of amino acids was studied based on extracellular metabolome, global transcriptome and proteome analysis. A new growth medium was designed with reduced amino acid concentrations to increase precision of measurements of consumption of amino acids. Consumption patterns were calculated for all 20 amino acids and measured carbon balance showed good fit of the data at all growth rates studied. It was observed that metabolism of L. lactis became more efficient with rising specific growth rate in the range 0.10 - 0.60 h-1, indicated by 30% increase in biomass yield based on glucose consumption, 50% increase in efficiency of nitrogen use for biomass synthesis, and 40% reduction in energy spilling. The latter was realized by decrease in the overall product formation and higher efficiency of incorporation of amino acids into biomass. L. lactis global transcriptome and proteome profiles showed good correlation supporting the general idea of transcription level control of bacterial metabolism, but the data indicated that substrate transport systems together with lower part of glycolysis in L. lactis were presumably under allosteric control. Conclusions The current study demonstrates advantages of the usage of strictly controlled continuous cultivation methods combined with multi-omics approach for quantitative understanding of amino acid and energy metabolism of L. lactis which is a valuable new knowledge for development of balanced growth media, gene manipulations for desired product

  15. MEASURING TINY MASS ACCRETION RATES ONTO YOUNG BROWN DWARFS

    International Nuclear Information System (INIS)

    Herczeg, Gregory J.; Cruz, Kelle L.; Hillenbrand, Lynne A.

    2009-01-01

    We present low-resolution Keck I/LRIS spectra spanning from 3200 to 9000 A of nine young brown dwarfs and three low-mass stars in the TW Hya Association and in Upper Sco. The optical spectral types of the brown dwarfs range from M5.5 to M8.75, though two have near-IR spectral types of early L dwarfs. We report new accretion rates derived from excess Balmer continuum emission for the low-mass stars TW Hya and Hen 3-600A and the brown dwarfs 2MASS J12073347-3932540, UScoCTIO 128, SSSPM J1102-3431, USco J160606.29-233513.3, DENIS-P J160603.9-205644, and Oph J162225-240515B, and upper limits on accretion for the low-mass star Hen 3-600B and the brown dwarfs UScoCTIO 112, Oph J162225-240515A, and USco J160723.82-221102.0. For the six brown dwarfs in our sample that are faintest at short wavelengths, the accretion luminosity or upper limit is measurable only when the image is binned over large wavelength intervals. This method extends our sensitivity to accretion rate down to ∼10 -13 M sun yr -1 for brown dwarfs. Since the ability to measure an accretion rate from excess Balmer continuum emission depends on the contrast between excess continuum emission and the underlying photosphere, for objects with earlier spectral types the upper limit on accretion rate is much higher. Absolute uncertainties in our accretion rate measurements of ∼3-5 include uncertainty in accretion models, brown dwarf masses, and distance. The accretion rate of 2 x 10 -12 M sun yr -1 onto 2MASS J12073347-3932540 is within 15% of two previous measurements, despite large changes in the Hα flux.

  16. Waste tank ventilation rates measured with a tracer gas method

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Evans, J.C.; Sklarew, D.S.; Mitroshkov, A.V.

    1998-08-01

    Passive ventilation with the atmosphere is used to prevent accumulation of waste gases and vapors in the headspaces of 132 of the 177 high-level radioactive waste Tanks at the Hanford Site in Southeastern Washington State. Measurements of the passive ventilation rates are needed for the resolution of two key safety issues associated with the rates of flammable gas production and accumulation and the rates at which organic salt-nitrate salt mixtures dry out. Direct measurement of passive ventilation rates using mass flow meters is not feasible because ventilation occurs va multiple pathways to the atmosphere (i.e., via the filtered breather riser and unsealed tank risers and pits), as well as via underground connections to other tanks, junction boxes, and inactive ventilation systems. The tracer gas method discussed in this report provides a direct measurement of the rate at which gases are removed by ventilation and an indirect measurement of the ventilation rate. The tracer gas behaves as a surrogate of the waste-generated gases, but it is only diminished via ventilation, whereas the waste gases are continuously released by the waste and may be subject to depletion mechanisms other than ventilation. The fiscal year 1998 tracer studies provide new evidence that significant exchange of air occurs between tanks via the underground cascade pipes. Most of the single-shell waste tanks are connected via 7.6-cm diameter cascade pipes to one or two adjacent tanks. Tracer gas studies of the Tank U-102/U-103 system indicated that the ventilation occurring via the cascade line could be a significant fraction of the total ventilation. In this two-tank cascade, air evidently flowed from Tank U-103 to Tank U-102 for a time and then was observed to flow from Tank U-102 to Tank U-103

  17. 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

    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...

  18. Effects of triiodothyronine on turnover rate and metabolizing enzymes for thyroxine in thyroidectomized rats.

    Science.gov (United States)

    Nagao, Hidenori; Sasaki, Makoto; Imazu, Tetsuya; Takahashi, Kenjo; Aoki, Hironori; Minato, Kouichi

    2014-10-29

    Previous studies in rats have indicated that surgical thyroidectomy represses turnover of serum thyroxine (T4). However, the mechanism of this process has not been identified. To clarify the mechanism, we studied adaptive variation of metabolic enzymes involved in T4 turnover. We compared serum T4 turnover rates in thyroidectomized (Tx) rats with or without infusion of active thyroid hormone, triiodothyronine (T3). Furthermore, the levels of mRNA expression and activity of the metabolizing enzymes, deiodinase type 1 (D1), type 2 (D2), uridine diphosphate-glucuronosyltransferase (UGT), and sulfotransferase were also compared in several tissues with or without T3 infusion. After the T3 infusion, the turnover rate of serum T4 in Tx rats returned to normal. Although mRNA expression and activity of D1 decreased significantly in both liver and kidneys without T3 infusion, D2 expression and activity increased markedly in the brain, brown adipose tissue, and skeletal muscle. Surprisingly, hepatic UGT mRNA expression and activity in Tx rats increased significantly in comparison with normal rats, and returned to normal after T3 infusion. This study suggests that repression of the disappearance of serum T4 in rats after Tx is a homeostatic response to decreased serum T3 concentrations. Additionally, T4 glucuronide is a storage form of T4, but may also have biological significance. These results suggest strongly that repression of deiodination of T4 by D1 in the liver and kidneys plays a major role in thyroid hormone homeostasis in Tx rats, and that hepatic UGT also plays a key role in this mechanism. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Measurement for the Leak Rate enhanced by a Improved Method

    International Nuclear Information System (INIS)

    Bae, Sang-Hoon; Choi, Young-San; Kim, Young-Ki; Lee, Yong-Sub; Jung, Hoan-Sung

    2007-01-01

    The leak rate measurement of the HANARO such as a research reactor that adopts a confinement concept for a reactor hall is very important one during a period inspection. This test verifies whether the reactor building could maintain the negative pressure or not when radiation is perceived by abnormal accidents. Of course, this may not cause a problem in a reactor operation only if it can satisfy the design requirement, but it is necessary to have some margin of a limitation value because a reactor hall should be managed more conservatively than the design reference. To meet the requirements of this strict design condition, previous method was changed to a new type of test with more stable and robust measuring method. The new leak rate measurement method is briefly introduced and the merits of this proposed method are shown through the data analyzed for last 3 years

  20. Morph-specific metabolic rate and the timing of reproductive senescence in a color polymorphic dragon.

    Science.gov (United States)

    Friesen, Christopher R; Johansson, Rasmus; Olsson, Mats

    2017-08-01

    Polymorphism has fascinated biologists for over a century because morphs persist within populations through evolutionary time in spite of showing disparate behavioral and physiological phenotypes; any one morph should go to fixation with the slightest fitness advantage over the others. Surely there must be trade-offs that balance selection on them. The polychromatic morphs of the Australian painted dragon lizard, Ctenophorus pictus, are one such system. The male color morphs of painted dragons have different physiological and behavioral traits including reproductive tactics, hormone levels, and the rate of body condition loss through the reproductive season. Due to their differences in physiology and reproductive tactics, we tested the hypotheses that male morphs would differ in resting metabolic rates (RMRs) and that the morphs' RMR would decline at different rates through the mating season. We found that bib-morphs (yellow gular patch) differ in RMR with bibbed (more aggressive) males having consistently higher RMR than non-bibbed males. Furthermore, we show that male dragons experience a decline in RMR as they age from reproductively active to inactive. We also found that the RMR of bibbed males has higher repeatability than non-bibbed males. Our results reinforce previous hypotheses about the morph-specific costs of bearing a gular patch in painted dragons. © 2017 Wiley Periodicals, Inc.

  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. High-temperature rate constant measurements for OH+xylenes

    KAUST Repository

    Elwardani, Ahmed Elsaid

    2015-06-01

    The overall rate constants for the reactions of hydroxyl (OH) radicals with o-xylene (k 1), m-xylene (k 2), and p-xylene (k 3) were measured behind reflected shock waves over 890-1406K at pressures of 1.3-1.8atm using OH laser absorption near 306.7nm. Measurements were performed under pseudo-first-order conditions. The measured rate constants, inferred using a mechanism-fitting approach, can be expressed in Arrhenius form as:k1=2.93×1013exp(-1350.3/T)cm3mol-1s-1(890-1406K)k2=3.49×1013exp(-1449.3/T)cm3mol-1s-1(906-1391K)k3=3.5×1013exp(-1407.5/T)cm3mol-1s-1(908-1383K)This paper presents, to our knowledge, first high-temperature measurements of the rate constants of the reactions of xylene isomers with OH radicals. Low-temperature rate-constant measurements by Nicovich et al. (1981) were combined with the measurements in this study to obtain the following Arrhenius expressions, which are applicable over a wider temperature range:k1=2.64×1013exp(-1181.5/T)cm3mol-1s-1(508-1406K)k2=3.05×109exp(-400/T)cm3mol-1s-1(508-1391K)k3=3.0×109exp(-440/T)cm3mol-1s-1(526-1383K) © 2015 The Combustion Institute.

  3. Microbial catabolic activities are naturally selected by metabolic energy harvest rate.

    Science.gov (United States)

    González-Cabaleiro, Rebeca; Ofiţeru, Irina D; Lema, Juan M; Rodríguez, Jorge

    2015-12-01

    The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate.

  4. Direct monitoring by carbon-13 nuclear magnetic resonance spectroscopy of the metabolism and metabolic rate of 13C-labeled compounds in vivo.

    Science.gov (United States)

    Iida, K; Hidoh, O; Fukami, J; Kajiwara, M

    1991-01-01

    Carbon-13 nuclear magnetic resonance spectroscopy has been used to observe the transformations of [1-13C]-D-glucose to [1,1'-13C2]-D-trehalose, and [3-13C]-L-alanine to [2-13C]-L-glutamic acid in the living body of Gryllodes sigillatus. [3-13C]-D-Alanine was not metabolized. The metabolic rate of [1-13C]-D-glucose was found to be altered by prior injection of boric acid.

  5. How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox

    DEFF Research Database (Denmark)

    Snoep, Jacky L.; Jensen, Peter Ruhdal; Groeneveld, Philip

    1994-01-01

    how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat. We develop metabolic control analysis for the chemostat. this analysis does not depend on the particular way in which specific growth rate varies with the concentration of the growth...

  6. Seasonal Oxygen Dynamics in a Warm Temperate Estuary: Effects of Hydrologic Variability on Measurements of Primary Production, Respiration, and Net Metabolism

    Science.gov (United States)

    Seasonal responses in estuarine metabolism (primary production, respiration, and net metabolism) were examined using two complementary approaches. Total ecosystem metabolism rates were calculated from dissolved oxygen time series using Odum’s open water method. Water column rates...

  7. Precedents For Authorization Of Contents Using Dose Rate Measurements

    International Nuclear Information System (INIS)

    Abramczyk, G.; Bellamy, S.; Nathan, S.; Loftin, B.

    2012-01-01

    For the transportation of Radioactive Material (RAM) packages, the requirements for the maximum allowed dose rate at the package surface and in its vicinity are given in Title 10 of the Code of Federal Regulations, Section 71.47. The regulations are based on the acceptable dose rates to which the public, workers, and the environment may be exposed. As such, the regulations specify dose rates, rather than quantity of radioactive isotopes and require monitoring to confirm the requirements are met. 10CFR71.47 requires that each package of radioactive materials offered for transportation must be designed and prepared for shipment so that under conditions normally incident to transportation the radiation level does not exceed 2 mSv/h (200 mrem/h) at any point on the external Surface of the package, and the transport index does not exceed 10. Before shipment, the dose rate of the package is determined by measurement, ensuring that it conforms to the regulatory limits, regardless of any analyses. This is the requirement for all certified packagings. This paper discusses the requirements for establishing the dose rates when shipping RAM packages and the precedents for meeting these requirements by measurement.

  8. MEASURING THE EVOLUTIONARY RATE OF COOLING OF ZZ Ceti

    Energy Technology Data Exchange (ETDEWEB)

    Mukadam, Anjum S.; Fraser, Oliver; Riecken, T. S.; Kronberg, M. E. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Bischoff-Kim, Agnes [Georgia College and State University, Milledgeville, GA 31061 (United States); Corsico, A. H. [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata (Argentina); Montgomery, M. H.; Winget, D. E.; Hermes, J. J.; Winget, K. I.; Falcon, Ross E.; Reaves, D. [Department of Astronomy, University of Texas at Austin, Austin, TX 78759 (United States); Kepler, S. O.; Romero, A. D. [Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, RS (Brazil); Chandler, D. W. [Meyer Observatory, Central Texas Astronomical Society, 3409 Whispering Oaks, Temple, TX 76504 (United States); Kuehne, J. W. [McDonald Observatory, Fort Davis, TX 79734 (United States); Sullivan, D. J. [Victoria University of Wellington, P.O. Box 600, Wellington (New Zealand); Von Hippel, T. [Embry-Riddle Aeronautical University, 600 South Clyde Morris Boulevard, Daytona Beach, FL 32114 (United States); Mullally, F. [SETI Institute, NASA Ames Research Center, MS 244-30, Moffet Field, CA 94035 (United States); Shipman, H. [Delaware Asteroseismic Research Center, Mt. Cuba Observatory, Greenville, DE 19807 (United States); and others

    2013-07-01

    We have finally measured the evolutionary rate of cooling of the pulsating hydrogen atmosphere (DA) white dwarf ZZ Ceti (Ross 548), as reflected by the drift rate of the 213.13260694 s period. Using 41 yr of time-series photometry from 1970 November to 2012 January, we determine the rate of change of this period with time to be dP/dt = (5.2 {+-} 1.4) Multiplication-Sign 10{sup -15} s s{sup -1} employing the O - C method and (5.45 {+-} 0.79) Multiplication-Sign 10{sup -15} s s{sup -1} using a direct nonlinear least squares fit to the entire lightcurve. We adopt the dP/dt obtained from the nonlinear least squares program as our final determination, but augment the corresponding uncertainty to a more realistic value, ultimately arriving at the measurement of dP/dt = (5.5 {+-} 1.0) Multiplication-Sign 10{sup -15} s s{sup -1}. After correcting for proper motion, the evolutionary rate of cooling of ZZ Ceti is computed to be (3.3 {+-} 1.1) Multiplication-Sign 10{sup -15} s s{sup -1}. This value is consistent within uncertainties with the measurement of (4.19 {+-} 0.73) Multiplication-Sign 10{sup -15} s s{sup -1} for another similar pulsating DA white dwarf, G 117-B15A. Measuring the cooling rate of ZZ Ceti helps us refine our stellar structure and evolutionary models, as cooling depends mainly on the core composition and stellar mass. Calibrating white dwarf cooling curves with this measurement will reduce the theoretical uncertainties involved in white dwarf cosmochronometry. Should the 213.13 s period be trapped in the hydrogen envelope, then our determination of its drift rate compared to the expected evolutionary rate suggests an additional source of stellar cooling. Attributing the excess cooling to the emission of axions imposes a constraint on the mass of the hypothetical axion particle.

  9. Evaporation rate measurement in the pool of IEAR-1 reactor

    International Nuclear Information System (INIS)

    Torres, Walmir Maximo; Cegalla, Miriam A.; Baptista Filho, Benedito Dias

    2000-01-01

    The surface water evaporation in pool type reactors affects the ventilation system operation and the ambient conditions and dose rates in the operation room. This paper shows the results of evaporation rate experiment in the pool of IEA-R1 research reactor. The experiment is based on the demineralized water mass variation inside cylindrical metallic recipients during a time interval. Other parameters were measured, such as: barometric pressure, relative humidity, environmental temperature, water temperature inside the recipients and water temperature in the reactor pool. The pool level variation due to water contraction/expansion was calculated. (author)

  10. Field measurement and interpretation of beta doses and dose rates

    International Nuclear Information System (INIS)

    Selby, J.M.; Swinth, K.L.; Hooker, C.D.; Kenoyer, J.L.

    1983-01-01

    A wide variety of portable survey instruments employing GM, ionization chamber and scintillation detectors exist for the measurement of gamma exposure rates. Often these same survey instruments are used for monitoring beta fields. This is done by making measurements with and without a removable shield which is intended to shield out the non-penetrating component (beta) of the radiation field. The difference does not correspond to an absorbed dose rate for the beta field due to a variety of factors. Among these factors are the dependence on beta energy, source-detector geometries, mixed fields and variable ambient conditions. Attempting to use such measurements directly can lead to errors as high as a factor of 100. In many instances correction factors have been derived, that if properly applied, can reduce these errors substantially. However, this requires some knowledge of the beta spectra, calibration techniques and source geometry. This paper discusses some aspects of the proper use of instruments for beta measurements including the application of appropriate correction factors. Ionization type instruments are commonly used to measure beta dose rates. Through design and calibration these instruments will give an accurate reading only for uniform irradiation of the detection volume. Often in the field it is not feasible to meet these conditions. Large area uniform distributions of activity are not generally encountered and it is not possible to use large source-to-detector distances due to beta particle absorption in air. An example of correction factors required for various point sources is presented when a cutie pie ionization chamber is employed. The instrument reading is multiplied by the appropriate correction factor to obtain the dose rate at the window. When a different detector is used or for other geometries, a different set of correction factors must be used

  11. Noninvasive quantification of cerebral metabolic rate for glucose in rats using 18F-FDG PET and standard input function

    Science.gov (United States)

    Hori, Yuki; Ihara, Naoki; Teramoto, Noboru; Kunimi, Masako; Honda, Manabu; Kato, Koichi; Hanakawa, Takashi

    2015-01-01

    Measurement of arterial input function (AIF) for quantitative positron emission tomography (PET) studies is technically challenging. The present study aimed to develop a method based on a standard arterial input function (SIF) to estimate input function without blood sampling. We performed 18F-fluolodeoxyglucose studies accompanied by continuous blood sampling for measurement of AIF in 11 rats. Standard arterial input function was calculated by averaging AIFs from eight anesthetized rats, after normalization with body mass (BM) and injected dose (ID). Then, the individual input function was estimated using two types of SIF: (1) SIF calibrated by the individual's BM and ID (estimated individual input function, EIFNS) and (2) SIF calibrated by a single blood sampling as proposed previously (EIF1S). No significant differences in area under the curve (AUC) or cerebral metabolic rate for glucose (CMRGlc) were found across the AIF-, EIFNS-, and EIF1S-based methods using repeated measures analysis of variance. In the correlation analysis, AUC or CMRGlc derived from EIFNS was highly correlated with those derived from AIF and EIF1S. Preliminary comparison between AIF and EIFNS in three awake rats supported an idea that the method might be applicable to behaving animals. The present study suggests that EIFNS method might serve as a noninvasive substitute for individual AIF measurement. PMID:25966947

  12. The measurement of the nigrostriatal dopaminergic function and glucose metabolism in patients with movement disorders

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Makoto; Ichiya, Yuichi; Kuwabara, Yasuo; Sasaki, Masayuki; Fukumura, Toshimitsu; Masuda, Kouji; Shima, Fumio; Kato, Motohiro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1992-12-01

    The nigrostriatal dopaminergic function and glucose metabolism were evaluated in 34 patients with various movement disorders by using positron emission tomography with [sup 18]F-Dopa and [sup 18]F-FDG respectively. The [sup 18]F-Dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The [sup 18]F-Dopa uptake in the striatum also decreased in cases of atypical parkinsonism and in cases of progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral hemisphere including the striatum; this finding was also different from those of Parkinson's disease. A normal [sup 18]F-Dopa uptake in the striatum with a markedly decreased striatal glucose metabolism and a mildly decreased cortical glucose metabolism was observed in cases of Huntington's disease and Wilson's disease. The [sup 18]F-Dopa uptake in the striatum increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of [sup 18]F-Dopa uptake and glucose metabolism were thus observed in the various movement disorders. These results suggest that the measurements of the [sup 18]F-Dopa uptake and the cerebral glucose metabolism would be useful for the evaluation of the striatal function in various movement disorders. (author).

  13. The Association Between Measures of Fitness and Metabolic Health in Treatment-Seeking Youth with Obesity.

    Science.gov (United States)

    Guseman, Emily Hill; Cauffman, Samuel P; Tucker, Jared M; Smith, Lucie; Eisenmann, Joey C; Stratbucker, William

    2017-04-01

    Both cardiorespiratory fitness (CRF) and measures of muscular fitness are associated with metabolic syndrome in adults. However, limited information exists about these relationships in youth with severe obesity who are at increased risk of metabolic dysfunction. The purpose of this study was to examine the relationship between fitness and metabolic health in treatment-seeking youth with obesity. Data for this analysis were collected at the time of baseline visits at a stage 3 pediatric weight management center. Maximal voluntary contractions were obtained by using isometric hand-grip dynamometry, and CRF was obtained from a maximal treadmill test. Resting blood pressure and fasting measures of blood lipids, glucose, and insulin were used to calculate a continuous metabolic syndrome score (cMetS); homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting insulin and glucose. Relationships between measures of fitness and metabolic health were evaluated by using partial correlations adjusted for age. Sixty-nine participants (21 boys, 48 girls) were included in this analysis. Of these, 46% (n = 32) met the criteria for metabolic syndrome. No differences were found between boys and girls for any variable analyzed. Muscular strength was positively associated with cMetS (r = 0.35), though this association weakened after adjustment for body mass index percentile. CRF was inversely associated with homeostasis model assessment of insulin resistance (HOMA-IR) (r = -0.26) and fasting insulin (r = -0.27). Body fat percentage was positively associated with insulin (r = 0.36). No significant relationship was found between CRF and cMetS. Contrary to previous studies, CRF was not associated with metabolic syndrome in this group. Muscular strength, however, was associated with cMetS. Notably, CRF was associated with elevated HOMA-IR, which may be seen as a precursor to metabolic syndrome. These results suggest that CRF and muscular

  14. Dosimetric measurement of the disintegration rate of fission products

    International Nuclear Information System (INIS)

    Solymosi, J.; Nagy, L.G.; Zagyvai, P.

    1992-01-01

    Investigations on the disintegration rate of fission products of 238 U and 239 Pu are presented. The intensity of the β-and γ-radiation of fission products were measured continously in an interval of 1-1300 hours following the fission, offering the possibility for determining the general and specific characteristics of the individual fission products. A universal measuring procedure was elaborated for the rapid in situ determination of the dosimetric features of fission products, which is suitable for the accurate evaluation and prediction of external absorbed dose even in case of fission products of various origin and unknown composition. (author) 6 refs.; 7 figs.; 1 tab

  15. Miniature electron bombardment evaporation source: evaporation rate measurement

    International Nuclear Information System (INIS)

    Nehasil, V.; Masek, K.; Matolin, V.; Moreau, O.

    1997-01-01

    Miniature electron beam evaporation sources which operate on the principle of vaporization of source material, in the form of a tip, by electron bombardment are produced by several companies specialized in UHV equipment. These sources are used primarily for materials that are normally difficult to deposit due to their high evaporation temperature. They are appropriate for special applications such as heteroepitaxial thin film growth requiring a very low and well controlled deposition rate. A simple and easily applicable method of evaporation rate control is proposed. The method is based on the measurement of ion current produced by electron bombardment of evaporated atoms. The absolute evaporation flux values were measured by means of the Bayard-Alpert ion gauge, which enabled the ion current vs evaporation flux calibration curves to be plotted. (author). 1 tab., 4 figs., 6 refs

  16. In situ measurements of thoron exhalation rate in Okinawa (Japan)

    International Nuclear Information System (INIS)

    Shiroma, Y.; Isa, N.; Hosoda, M.; Sorimachi, A.; Ishikawa, T.; Tokonami, S.; Furukawa, M.

    2010-01-01

    Thoron exhalation rates from the ground surface were measured at 57 sites on Okinawa Island (Japan), using a ZnS(Ag) scintillation detector equipped with photomultiplier. The arithmetic means ± SD, median ± SD, minimum and maximum of the rates (unit: Bq m -2 s -1 ) were estimated to be 1.9 ± 1.4, 1.6 ± 0.3, 0.04 and 6.2, respectively. The soils distributed on the island are generally classified into dark red soils, residual regosols, as well as red and yellow soils. While it was assumed that the soils were originated from the bedrock, recent studies suggested that the main material of dark red soils is the East Asian eolian dust. In the dark red soils area, the exhalation rate is relatively higher than that in the other areas. This suggested that the eolian dust was an enhancer for the environmental thoron concentration on Okinawa Island. (authors)

  17. Does basal metabolic rate contain a useful signal? Mammalian BMR allometry and correlations with a selection of physiological, ecological, and life-history variables.

    Science.gov (United States)

    White, Craig R; Seymour, Roger S

    2004-01-01

    Basal metabolic rate (BMR, mL O2 h(-1)) is a useful measurement only if standard conditions are realised. We present an analysis of the relationship between mammalian body mass (M, g) and BMR that accounts for variation associated with body temperature, digestive state, and phylogeny. In contrast to the established paradigm that BMR proportional to M3/4, data from 619 species, representing 19 mammalian orders and encompassing five orders of magnitude variation in M, show that BMR proportional to M2/3. If variation associated with body temperature and digestive state are removed, the BMRs of eutherians, marsupials, and birds do not differ, and no significant allometric exponent heterogeneity remains between orders. The usefulness of BMR as a general measurement is supported by the observation that after the removal of body mass effects, the residuals of BMR are significantly correlated with the residuals for a variety of physiological and ecological variables, including maximum metabolic rate, field metabolic rate, resting heart rate, life span, litter size, and population density.

  18. 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.

  19. Nitrogen metabolism and protozoa production rate in cattle fed on diet containing protected protein

    International Nuclear Information System (INIS)

    Singh, G.P.; Gupta, B.N.

    1992-01-01

    Nitrogen metabolism and protozoa production rate using 14 C-choline as marker were studied on 9 adult male crossbred (Tharparker x Brown Swiss) rumen fistulated animals divided into 3 groups (A, B and C). All the animals were fed concentrate mixture and wheatstraw. However, groundnut cake (GNC) in concentrate mixture was untreated in group A, 50 per cent formaldehyde treated in group B and 100 per cent formaldehyde treated in group C. Although, DM intake was similar in these groups but water intake was significantly (P<0.05) higher in control group. Total-N, ammonia-N and blood urea were significantly lower in group B and C as compared to group A. Apparent CP digestibility was not affected by addition of formaldehyde treated GNC at 50 and 100 per cent levels. However, N balances increased significantly (P<0.05) due to addition of protected protein in diet. Protozoal pool as well as production rate were significantly (P<0.01) decreased due to formaldehyde treatment of GNC protein. Thus addition of formaldehyde treated GNC in diets decreased ammonia and protozoa production but increased N retention in groups B and C. (author). 27 refs., 3 tabs., 2 figs

  20. Measurement of soluble nuclide dissolution rates from spent fuel

    International Nuclear Information System (INIS)

    Wilson, C.N.; Gray, W.J.

    1990-01-01

    Gaining a better understanding of the potential release behavior of water-soluble radionuclides is the focus of new laboratory spent fuel dissolution studies being planned in support of the Yucca Mountain Project. Previous studies have suggested that maximum release rates for actinide nuclides, which account for most of the long-term radioactivity in spent fuel, should be solubility-limited and should not depend on the characteristics or durability of the spent fuel waste form. Maximum actinide concentrations should be sufficiently low to meet the NRC (Nuclear Regulatory Commission) annual release limits. Potential release rates for soluble nuclides such as 99 Tc, 135 Cs, 14 C and 129 I, which account for about 1-2% of the activity in spent fuel at 1,000 years, are less certain and may depend on processes such as oxidation of the fuel in the repository air environment. Dissolution rates for several soluble nuclides have been measured from spent fuel specimens using static and semi-static methods. However, such tests do not provide a direct measurement of fuel matrix dissolution rates that may ultimately control soluble-nuclide release rates. Flow-through tests are being developed as a potential supplemental method for determining the matrix component of soluble-nuclide dissolution. Advantages and disadvantages of both semi-static and flow-through methods are discussed. Tests with fuel specimens representing a range of potential fuel states that may occur in the repository, including oxidized fuel, are proposed. Preliminary results from flow-through tests with unirradiated UO 2 suggesting that matrix dissolution rates are very sensitive to water composition are also presented

  1. Sleep-Wake Differences in Relative Regional Cerebral Metabolic Rate for Glucose among Patients with Insomnia Compared with Good Sleepers

    Science.gov (United States)

    Kay, Daniel B.; Karim, Helmet T.; Soehner, Adriane M.; Hasler, Brant P.; Wilckens, Kristine A.; James, Jeffrey A.; Aizenstein, Howard J.; Price, Julie C.; Rosario, Bedda L.; Kupfer, David J.; Germain, Anne; Hall, Martica H.; Franzen, Peter L.; Nofzinger, Eric A.; Buysse, Daniel J.

    2016-01-01

    Study Objectives: The neurobiological mechanisms of insomnia may involve altered patterns of activation across sleep-wake states in brain regions associated with cognition, self-referential processes, affect, and sleep-wake promotion. The objective of this study was to compare relative regional cerebral metabolic rate for glucose (rCMRglc) in these brain regions across wake and nonrapid eye movement (NREM) sleep states in patients with primary insomnia (PI) and good sleeper controls (GS). Methods: Participants included 44 PI and 40 GS matched for age (mean = 37 y old, range 21–60), sex, and race. We conducted [18F]fluoro-2-deoxy-d-glucose positron emission tomography scans in PI and GS during both morning wakefulness and NREM sleep at night. Repeated measures analysis of variance was used to test for group (PI vs. GS) by state (wake vs. NREM sleep) interactions in relative rCMRglc. Results: Significant group-by-state interactions in relative rCMRglc were found in the precuneus/posterior cingulate cortex, left middle frontal gyrus, left inferior/superior parietal lobules, left lingual/fusiform/occipital gyri, and right lingual gyrus. All clusters were significant at Pcorrected sleep and wakefulness. Significant group-by-state interactions in relative rCMRglc suggest that insomnia is associated with impaired disengagement of brain regions involved in cognition (left frontoparietal), self-referential processes (precuneus/posterior cingulate), and affect (left middle frontal, fusiform/lingual gyri) during NREM sleep, or alternatively, to impaired engagement of these regions during wakefulness. Citation: Kay DB, Karim HT, Soehner AM, Hasler BP, Wilckens KA, James JA, Aizenstein HJ, Price JC, Rosario BL, Kupfer DJ, Germain A, Hall MH, Franzen PL, Nofzinger EA, Buysse DJ. Sleep-wake differences in relative regional cerebral metabolic rate for glucose among patients with insomnia compared with good sleepers. SLEEP 2016;39(10):1779–1794. PMID:27568812

  2. Measurement of sulfur dioxide oxidation rates in wintertime orographic clouds

    International Nuclear Information System (INIS)

    Snider, J.R.

    1990-01-01

    SO2-reaction studies in the clouds are examined and summarized to experimentally confirm model predictions and previous field studies regarding dominant SO2-reaction pathways. Controlled amounts of SO2 were released into nonprecipitating orographic clouds, and sulfate yields are compared to oxidant depletions. The sulfate yields were taken from cloud-water samples and liquid-water-concentration measurements, and oxidant-depletion data were generated from continuous gas-phase measurements. Comparisons of Y sub SO4 and D sub H2O2 suggest that H2O2 is the dominant oxidant, and the in-cloud reaction between H2O2 and the bisulfite ion can be expressed by a simple rate that agrees with predictions and laboratory results. The rate measurements are found to be inconsistent with the rate law proposed by Hegg and Hobbs (1982) and with some observational data. The present conclusions are of interest to evaluating the effects of sulfur dioxide emissions on sulfuric acid deposition. 30 refs

  3. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography ( 13 N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique

  4. On the bromine metabolism in uraemia, measured with PIXE

    International Nuclear Information System (INIS)

    Vis, R.D.; Bos, A.J.J.; Verheul, H.; Oe, P.L.; Vrije Univ., Amsterdam

    1981-01-01

    Among other elements, a Br - depletion associated with the uraemic state has been measured earlier [1,2]. It is most probable that this depletion is caused by the treatment with the artificial kidney and therefore the transport of Br - has been measured in an in vitro experiment. A correlation is made between the serum concentration of Br - and complaints of the patients about sleep disturbances. It is the intention to increase Br - levels in the dialysis solution used, in order to improve sleep quality. (orig.)

  5. Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate.

    Directory of Open Access Journals (Sweden)

    Maxi Meissner

    Full Text Available AIMS/HYPOTHESIS: Bile acid sequestrants (BAS reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology. METHODS: Lean and diabetic db/db mice were treated with 2% (wt/wt in diet Colesevelam HCl (BAS for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-(13C]-glucose, [2-(13C]-glycerol, [1-(2H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns. RESULTS: Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001, a ∼300% increased glucokinase flux (p = 0.001 and a ∼200% increased total hepatic glucose production rate (p = 0.0002. BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317 but not in liver (p = 0.189. Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030 and 3-fold in db/db mice (p = 0.002. CONCLUSIONS/INTERPRETATION: BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.

  6. Inferring metabolic states in uncharacterized environments using gene-expression measurements.

    Directory of Open Access Journals (Sweden)

    Sergio Rossell

    Full Text Available The large size of metabolic networks entails an overwhelming multiplicity in the possible steady-state flux distributions that are compatible with stoichiometric constraints. This space of possibilities is largest in the frequent situation where the nutrients available to the cells are unknown. These two factors: network size and lack of knowledge of nutrient availability, challenge the identification of the actual metabolic state of living cells among the myriad possibilities. Here we address this challenge by developing a method that integrates gene-expression measurements with genome-scale models of metabolism as a means of inferring metabolic states. Our method explores the space of alternative flux distributions that maximize the agreement between gene expression and metabolic fluxes, and thereby identifies reactions that are likely to be active in the culture from which the gene-expression measurements were taken. These active reactions are used to build environment-specific metabolic models and to predict actual metabolic states. We applied our method to model the metabolic states of Saccharomyces cerevisiae growing in rich media supplemented with either glucose or ethanol as the main energy source. The resulting models comprise about 50% of the reactions in the original model, and predict environment-specific essential genes with high sensitivity. By minimizing the sum of fluxes while forcing our predicted active reactions to carry flux, we predicted the metabolic states of these yeast cultures that are in large agreement with what is known about yeast physiology. Most notably, our method predicts the Crabtree effect in yeast cells growing in excess glucose, a long-known phenomenon that could not have been predicted by traditional constraint-based modeling approaches. Our method is of immediate practical relevance for medical and industrial applications, such as the identification of novel drug targets, and the development of

  7. Measurement of blowdown flow rates using load cells

    International Nuclear Information System (INIS)

    Dolas, P.K.; Venkat Raj, V.; Ghosh, A.K.; Murty, L.G.K.; Muralidhar Rao, S.

    1980-01-01

    To establish a reliable method for measuring two-phase flow, experiments were planned for measurement of transient single phase flow rates from vessels using load cells. Suitability of lead-zirconate-titanate piezoelectric ceramic discs was examined. Discharge time constant of the disc used was low, leading to large measurement errors. Subsequently, experiments were carried out using strain gauge load cells and these were found satisfactory. The unsteady flow equation has been derived for the system under investigation. The equation has been solved numerically using the fourth order Runge-Kutta method and also by integrating it analytically. The experimental results are compared with the theoretical results and presented in this report. (auth.)

  8. Constrained independent component analysis approach to nonobtrusive pulse rate measurements

    Science.gov (United States)

    Tsouri, Gill R.; Kyal, Survi; Dianat, Sohail; Mestha, Lalit K.

    2012-07-01

    Nonobtrusive pulse rate measurement using a webcam is considered. We demonstrate how state-of-the-art algorithms based on independent component analysis suffer from a sorting problem which hinders their performance, and propose a novel algorithm based on constrained independent component analysis to improve performance. We present how the proposed algorithm extracts a photoplethysmography signal and resolves the sorting problem. In addition, we perform a comparative study between the proposed algorithm and state-of-the-art algorithms over 45 video streams using a finger probe oxymeter for reference measurements. The proposed algorithm provides improved accuracy: the root mean square error is decreased from 20.6 and 9.5 beats per minute (bpm) for existing algorithms to 3.5 bpm for the proposed algorithm. An error of 3.5 bpm is within the inaccuracy expected from the reference measurements. This implies that the proposed algorithm provided performance of equal accuracy to the finger probe oximeter.

  9. Field measurement and interpretation of beta doses and dose rates

    International Nuclear Information System (INIS)

    Selby, J.M.; Swinth, K.L.; Hooker, C.D.; Kenoyer, J.L.

    1983-01-01

    A large number of portable survey instruments employing G.M., ionization chamber, and scintillation detectors used for gamma measurements are also used for monitoring in beta fields by using removable shields to separate the beta and gamma components of the radiation field. The difference does not correspond to an absorbed dose rate for the beta field due to a variety of factors. Among these factors are the dependence on beta energy, source-detector geometries, mixed fields and variable ambient conditions. Attempting to use such measurements directly can lead to errors as high as a factor of 100. Appropriate calibrations and correction factors can be used to reduce the errors in beta measurements to a tolerable level

  10. Noninvasive Sensor for Measuring Muscle Metabolism During Exercise

    Science.gov (United States)

    Soller, B. R.; Yang, Y.; Lee, S. M. C.; Soyemi, O. O.; Wilson, C.; Hagan, R. D.

    2007-01-01

    The measurement of oxygen uptake (VO2) and lactate threshold (LT) are utilized to assess changes in aerobic capacity and the efficacy of exercise countermeasures in astronauts. During extravehicular activity (EVA), real-time knowledge of VO2 and relative work intensity can be used to monitor crew activity levels and organize tasks to reduce the cumulative effects of fatigue. Currently VO2 and LT are determined with complicated measurement techniques that require sampling of expired ventilatory gases, which may not be accurate in enclosed, oxygen-rich environments such as the EVA suit. The UMMS team has developed a novel near infrared spectroscopic (NIRS) system which noninvasively, simultaneously and continuously measures muscle oxygen tension, oxygen saturation, pH (pHm), and hematocrit from a small sensor placed on the leg. This system is unique in that it allows accurate, absolute measurement of these parameters in the thigh muscle by correcting spectra for the interference from skin pigment and fat. These parameters can be used to estimate VO2 and LT. A preliminary evaluation of the system s capabilities was performed in the NASA JSC Exercise Physiology Lab.

  11. 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

    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...

  12. Measurements of astrophysical reaction rates for radioactive samples

    International Nuclear Information System (INIS)

    Koehler, P.E.; O'Brien, H.A.; Bowman, C.D.

    1987-01-01

    Reaction rates for both big-bang and stellar nucleosynthesis can be obtained from the measurement of (n,p) and (n,γ) cross sections for radioactive nuclei. In the past, large backgrounds associated with the sample activity limited these types of measurements to radioisotopes with very long half lives. The advent of the low-energy, high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Results of (n,p) measurements on samples with half lives as short as fifty-three days will be given. The astrophysics to be learned from these data will be discussed. Additional difficulties are encountered when making (n,γ) rather than (n,p) measurements. However, with a properly designed detector, and with the high peak neutron intensities now available, (n,γ) measurements can be made for nuclei with half lives as short as several weeks. Progress on the Los Alamos (n,γ) cross-section measurement program for radioactive samples will be discussed. 25 refs., 3 figs., 1 tab

  13. A new high rate positron lifetime measurement system

    International Nuclear Information System (INIS)

    Bedwell, M.O.; Paulus, T.J.

    1979-01-01

    Positron lifetime measuring system, a technique to perform non-destructive studies on the internal structure of materials, has many components common to those used for nuclear time spectroscopy systems. In each case, a timing coincidence curve is measured for the energy range of interest, and this is accomplished in a typical timing coincidence system. The paper first describes the conventional timing coincidence system, then a new fast timing system is introduced. Comparing to the conventional fast/slow timing system, the fast timing technique offers reduced complexity, lower system cost, and improved high data rate capability. Experimental results show that the FWHM timing resolution ranges from 190 ps for a 1.1 : 1 dynamic range to 337 ps for a 100 : 1 dynamic range of signals with 60 Co. As for the timing resolution as a function of energy, the FWHM resolution for each channel ranges from 124 ps at 1 MeV to 400 ps at 100 keV. Since the excellent timing performance is maintained even at very high input rate, the experimenters can use much more active sources to increase the true coincidence rate and reduce data accumulation time. This method has the added advantage of minimizing long term drift effects since the experiments can be conducted in less time. (Wakatsuki, Y.)

  14. Measurements of waste tank passive ventilation rates using tracer gases

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Olsen, K.B.; Sklarew, D.S.; Evans, J.C.; Remund, K.M.

    1997-09-01

    This report presents the results of ventilation rate studies of eight passively ventilated high-level radioactive waste tanks using tracer gases. Head space ventilation rates were determined for Tanks A-101, AX-102, AX-103, BY-105, C-107, S-102, U-103, and U-105 using sulfur hexafluoride (SF 6 ) and/or helium (He) as tracer gases. Passive ventilation rates are needed for the resolution of several key safety issues. These safety issues are associated with the rates of flammable gas production and ventilation, the rates at which organic salt-nitrate salt mixtures dry out, and the estimation of organic solvent waste surface areas. This tracer gas study involves injecting a tracer gas into the tank headspace and measuring its concentration at different times to establish the rate at which the tracer is removed by ventilation. Tracer gas injection and sample collection were performed by SGN Eurisys Service Corporation and/or Lockheed Martin Hanford Corporation, Characterization Project Operations. Headspace samples were analyzed for He and SF 6 by Pacific Northwest National Laboratory (PNNL). The tracer gas method was first demonstrated on Tank S-102. Tests were conducted on Tank S-102 to verify that the tracer gas was uniformly distributed throughout the tank headspace before baseline samples were collected, and that mixing was sufficiently vigorous to maintain an approximately uniform distribution of tracer gas in the headspace during the course of the study. Headspace samples, collected from a location about 4 in away from the injection point and 15, 30, and 60 minutes after the injection of He and SF 6 , indicated that both tracer gases were rapidly mixed. The samples were found to have the same concentration of tracer gases after 1 hour as after 24 hours, suggesting that mixing of the tracer gas was essentially complete within 1 hour

  15. 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.

  16. Increasing ankle push-off work with a powered prosthesis does not necessarily reduce metabolic rate for transtibial amputees.

    Science.gov (United States)

    Quesada, Roberto E; Caputo, Joshua M; Collins, Steven H

    2016-10-03

    Amputees using passive ankle-foot prostheses tend to expend more metabolic energy during walking than non-amputees, and reducing this cost has been a central motivation for the development of active ankle-foot prostheses. Increased push-off work at the end of stance has been proposed as a way to reduce metabolic energy use, but the effects of push-off work have not been tested in isolation. In this experiment, participants with unilateral transtibial amputation (N=6) walked on a treadmill at a constant speed while wearing a powered prosthesis emulator. The prosthesis delivered different levels of ankle push-off work across conditions, ranging from the value for passive prostheses to double the value for non-amputee walking, while all other prosthesis mechanics were held constant. Participants completed six acclimation sessions prior to a data collection in which metabolic rate, kinematics, kinetics, muscle activity and user satisfaction were recorded. Metabolic rate was not affected by net prosthesis work rate (p=0.5; R 2 =0.007). Metabolic rate, gait mechanics and muscle activity varied widely across participants, but no participant had lower metabolic rate with higher levels of push-off work. User satisfaction was affected by push-off work (p=0.002), with participants preferring values of ankle push-off slightly higher than in non-amputee walking, possibly indicating other benefits. Restoring or augmenting ankle push-off work is not sufficient to improve energy economy for lower-limb amputees. Additional necessary conditions might include alternate timing or control, individualized tuning, or particular subject characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise

    Science.gov (United States)

    Everett, Meghan E.; Loehr, James A.; DeWitt, John K.; Laughlin, Mitzi; Lee, Stuart M. C.

    2010-01-01

    PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures.

  18. A mathematical framework for yield (vs. 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 one 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

  19. Nitrogen metabolism in the rumen and its measurement

    International Nuclear Information System (INIS)

    Nolan, J.V.; Leng, R.A.

    1983-01-01

    Methods are needed to maximize the synthesis of microbial protein in the rumen from readily available, inexpensive (usually non-protein N) sources and thereby to reduce the requirements for true protein in the diet. Some currently available in vitro and in vivo methods for estimating microbial protein synthesis in the rumen are discussed. The factors that alter maintenance ATP requirements of microorganisms, and thereby potentially alter the efficiency of cell growth per unit of fermented organic matter (Ysub(ATP)), are discussed: e.g. continuity and level of supply of substrates; dietary and recycled N and other nutrients; dilution rate; the presence of large protozoal populations in the rumen; cell lysis and N cycling in the rumen. Quantitative studies of these factors have been made by using a variety of isotope tracer techniques and have been applied to a quantitative model of N transactions in the rumen. (author)

  20. Scale factor measure method without turntable for angular rate gyroscope

    Science.gov (United States)

    Qi, Fangyi; Han, Xuefei; Yao, Yanqing; Xiong, Yuting; Huang, Yuqiong; Wang, Hua

    2018-03-01

    In this paper, a scale factor test method without turntable is originally designed for the angular rate gyroscope. A test system which consists of test device, data acquisition circuit and data processing software based on Labview platform is designed. Taking advantage of gyroscope's sensitivity of angular rate, a gyroscope with known scale factor, serves as a standard gyroscope. The standard gyroscope is installed on the test device together with a measured gyroscope. By shaking the test device around its edge which is parallel to the input axis of gyroscope, the scale factor of the measured gyroscope can be obtained in real time by the data processing software. This test method is fast. It helps test system miniaturized, easy to carry or move. Measure quarts MEMS gyroscope's scale factor multi-times by this method, the difference is less than 0.2%. Compare with testing by turntable, the scale factor difference is less than 1%. The accuracy and repeatability of the test system seems good.

  1. Process Measurement Deviation Analysis for Flow Rate due to Miscalibration

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Eunsuk; Kim, Byung Rae; Jeong, Seog Hwan; Choi, Ji Hye; Shin, Yong Chul; Yun, Jae Hee [KEPCO Engineering and Construction Co., Deajeon (Korea, Republic of)

    2016-10-15

    An analysis was initiated to identify the root cause, and the exemption of high static line pressure correction to differential pressure (DP) transmitters was one of the major deviation factors. Also the miscalibrated DP transmitter range was identified as another major deviation factor. This paper presents considerations to be incorporated in the process flow measurement instrumentation calibration and the analysis results identified that the DP flow transmitter electrical output decreased by 3%. Thereafter, flow rate indication decreased by 1.9% resulting from the high static line pressure correction exemption and measurement range miscalibration. After re-calibration, the flow rate indication increased by 1.9%, which is consistent with the analysis result. This paper presents the brief calibration procedures for Rosemount DP flow transmitter, and analyzes possible three cases of measurement deviation including error and cause. Generally, the DP transmitter is required to be calibrated with precise process input range according to the calibration procedure provided for specific DP transmitter. Especially, in case of the DP transmitter installed in high static line pressure, it is important to correct the high static line pressure effect to avoid the inherent systematic error for Rosemount DP transmitter. Otherwise, failure to notice the correction may lead to indicating deviation from actual value.

  2. Measurement of gastric emptying rate in humans. Simplified scanning method

    Energy Technology Data Exchange (ETDEWEB)

    Holt, S.; Colliver, J.; Guram, M.; Neal, C.; Verhulst, S.J.; Taylor, T.V. (Univ. of South Carolina School of Medicine, Columbia (USA))

    1990-11-01

    Simultaneous measurements of the gastric emptying rate of the solid and liquid phase of a dual-isotope-labeled test meal were made using a gamma camera and a simple scintillation detector, similar to that used in a hand-held probe. A simple scanning apparatus, similar to that used in a hand-held scintillation probe, was compared with simultaneous measurements made by a gamma camera in 16 healthy males. A dual-labeled test meal was utilized to measure liquid and solid emptying simultaneously. Anterior and posterior scans were taken at intervals up to 120 min using both a gamma camera and the scintillation probe. Good relative agreement between the methods was obtained both for solid-phase (correlation range 0.92-0.99, mean 0.97) and for liquid-phase data (correlation range 0.93-0.99, mean 0.97). For solid emptying data regression line slopes varied from 0.75 to 1.03 (mean 0.84). Liquid emptying data indicated that slopes ranged from 0.71 to 1.06 (mean 0.87). These results suggested that an estimate of the gamma measurement could be obtained by multiplying the scintillation measurement by a factor of 0.84 for the solid phase and 0.87 for the liquid phase. Correlation between repeat studies was 0.97 and 0.96 for solids and liquids, respectively. The application of a hand-held probe technique provides a noninvasive and inexpensive method for accurately assessing solid- and liquid-phase gastric emptying from the human stomach that correlates well with the use of a gamma camera, within the range of gastric emptying rate in the normal individuals in this study.

  3. Measurement of gastric emptying rate in humans. Simplified scanning method

    International Nuclear Information System (INIS)

    Holt, S.; Colliver, J.; Guram, M.; Neal, C.; Verhulst, S.J.; Taylor, T.V.

    1990-01-01

    Simultaneous measurements of the gastric emptying rate of the solid and liquid phase of a dual-isotope-labeled test meal were made using a gamma camera and a simple scintillation detector, similar to that used in a hand-held probe. A simple scanning apparatus, similar to that used in a hand-held scintillation probe, was compared with simultaneous measurements made by a gamma camera in 16 healthy males. A dual-labeled test meal was utilized to measure liquid and solid emptying simultaneously. Anterior and posterior scans were taken at intervals up to 120 min using both a gamma camera and the scintillation probe. Good relative agreement between the methods was obtained both for solid-phase (correlation range 0.92-0.99, mean 0.97) and for liquid-phase data (correlation range 0.93-0.99, mean 0.97). For solid emptying data regression line slopes varied from 0.75 to 1.03 (mean 0.84). Liquid emptying data indicated that slopes ranged from 0.71 to 1.06 (mean 0.87). These results suggested that an estimate of the gamma measurement could be obtained by multiplying the scintillation measurement by a factor of 0.84 for the solid phase and 0.87 for the liquid phase. Correlation between repeat studies was 0.97 and 0.96 for solids and liquids, respectively. The application of a hand-held probe technique provides a noninvasive and inexpensive method for accurately assessing solid- and liquid-phase gastric emptying from the human stomach that correlates well with the use of a gamma camera, within the range of gastric emptying rate in the normal individuals in this study

  4. The stratigraphic filter and bias in measurement of geologic rates

    Science.gov (United States)

    Schumer, Rina; Jerolmack, Douglas; McElroy, Brandon

    2011-01-01

    Erosion and deposition rates estimated from the stratigraphic record frequently exhibit a power-law dependence on measurement interval. This dependence can result from a power-law distribution of stratigraphic hiatuses. By representing the stratigraphic filter as a stochastic process called a reverse ascending ladder, we describe a likely origin of power-law hiatuses, and thus, rate scaling. While power-law hiatuses in certain environments can be a direct result of power-law periods of stasis (no deposition or erosion), they are more generally the result of randomness in surface fluctuations irrespective of mean subsidence or uplift. Autocorrelation in fluctuations can make hiatuses more or less heavy-tailed, but still exhibit power-law characteristics. In addition we show that by passing stratigraphic data backward through the filter, certain statistics of surface kinematics from their formative environments can be inferred.

  5. Astrocytic and neuronal oxidative metabolism are coupled to the rate of glutamate-glutamine cycle in the tree shrew visual cortex.

    Science.gov (United States)

    Sonnay, Sarah; Poirot, Jordan; Just, Nathalie; Clerc, Anne-Catherine; Gruetter, Rolf; Rainer, Gregor; Duarte, João M N

    2018-03-01

    Astrocytes play an important role in glutamatergic neurotransmission, namely by clearing synaptic glutamate and converting it into glutamine that is transferred back to neurons. The rate of this glutamate-glutamine cycle (V NT ) has been proposed to couple to that of glucose utilization and of neuronal tricarboxylic acid (TCA) cycle. In this study, we tested the hypothesis that glutamatergic neurotransmission is also coupled to the TCA cycle rate in astrocytes. For that we investigated energy metabolism by means of magnetic resonance spectroscopy (MRS) in the primary visual cortex of tree shrews (Tupaia belangeri) under light isoflurane anesthesia at rest and during continuous visual stimulation. After identifying the activated cortical volume by blood oxygenation level-dependent functional magnetic resonance imaging, 1 H MRS was performed to measure stimulation-induced variations in metabolite concentrations. Relative to baseline, stimulation of cortical activity for 20 min caused a reduction of glucose concentration by -0.34 ± 0.09 µmol/g (p glucose infusion was employed to measure fluxes of energy metabolism. Stimulation of glutamatergic activity, as indicated by a 20% increase of V NT , resulted in increased TCA cycle rates in neurons by 12% ( VTCAn, p glucose oxidation and to mitochondrial metabolism in both neurons and astrocytes. © 2017 Wiley Periodicals, Inc.

  6. Best-fitting prediction equations for basal metabolic rate: informing obesity interventions in diverse populations.

    Science.gov (United States)

    Sabounchi, N S; Rahmandad, H; Ammerman, A

    2013-10-01

    Basal metabolic rate (BMR) represents the largest component of total energy expenditure and is a major contributor to energy balance. Therefore, accurately estimating BMR is critical for developing rigorous obesity prevention and control strategies. Over the past several decades, numerous BMR formulas have been developed targeted to different population groups. A comprehensive literature search revealed 248 BMR estimation equations developed using diverse ranges of age, gender, race, fat-free mass, fat mass, height, waist-to-hip ratio, body mass index and weight. A subset of 47 studies included enough detail to allow for development of meta-regression equations. Utilizing these studies, meta-equations were developed targeted to 20 specific population groups. This review provides a comprehensive summary of available BMR equations and an estimate of their accuracy. An accompanying online BMR prediction tool (available at http://www.sdl.ise.vt.edu/tutorials.html) was developed to automatically estimate BMR based on the most appropriate equation after user-entry of individual age, race, gender and weight.

  7. 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.

  8. 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.

  9. Accuracy assessment of high-rate GPS measurements for seismology

    Science.gov (United States)

    Elosegui, P.; Davis, J. L.; Ekström, G.

    2007-12-01

    Analysis of GPS measurements with a controlled laboratory system, built to simulate the ground motions caused by tectonic earthquakes and other transient geophysical signals such as glacial earthquakes, enables us to assess the technique of high-rate GPS. The root-mean-square (rms) position error of this system when undergoing realistic simulated seismic motions is 0.05~mm, with maximum position errors of 0.1~mm, thus providing "ground truth" GPS displacements. We have acquired an extensive set of high-rate GPS measurements while inducing seismic motions on a GPS antenna mounted on this system with a temporal spectrum similar to real seismic events. We found that, for a particular 15-min-long test event, the rms error of the 1-Hz GPS position estimates was 2.5~mm, with maximum position errors of 10~mm, and the error spectrum of the GPS estimates was approximately flicker noise. These results may however represent a best-case scenario since they were obtained over a short (~10~m) baseline, thereby greatly mitigating baseline-dependent errors, and when the number and distribution of satellites on the sky was good. For example, we have determined that the rms error can increase by a factor of 2--3 as the GPS constellation changes throughout the day, with an average value of 3.5~mm for eight identical, hourly-spaced, consecutive test events. The rms error also increases with increasing baseline, as one would expect, with an average rms error for a ~1400~km baseline of 9~mm. We will present an assessment of the accuracy of high-rate GPS based on these measurements, discuss the implications of this study for seismology, and describe new applications in glaciology.

  10. Measuring glucose cerebral metabolism in the healthy mouse using hyperpolarized C-13 magnetic resonance

    DEFF Research Database (Denmark)

    Mishkovsky, Mor; Anderson, Brian; Karlsson, Magnus

    2017-01-01

    The mammalian brain relies primarily on glucose as a fuel to meet its high metabolic demand. Among the various techniques used to study cerebral metabolism, C-13 magnetic resonance spectroscopy (MRS) allows following the fate of C-13-enriched substrates through metabolic pathways. We herein...... glucose is split into 3-carbon intermediates by aldolase. This unique method allows direct detection of glycolysis in vivo in the healthy brain in a noninvasive manner....... demonstrate that it is possible to measure cerebral glucose metabolism in vivo with sub-second time resolution using hyperpolarized C-13 MRS. In particular, the dynamic C-13-labeling of pyruvate and lactate formed from C-13-glucose was observed in real time. An ad-hoc synthesis to produce [2,3,4,6,6-H-2(5), 3...

  11. Prospects for DNA methods to measure human heritable mutation rates

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1985-01-01

    A workshop cosponsored by ICPEMC and the US Department of Energy was held in Alta, Utah, December 9-13, 1984 to examine the extent to which DNA-oriented methods might provide new approaches to the important but intractable problem of measuring mutation rates in control and exposed human populations. The workshop identified and analyzed six DNA methods for detection of human heritable mutation, including several created at the meeting, and concluded that none of the methods combine sufficient feasibility and efficiency to be recommended for general application. 8 refs

  12. Visual rating of medial temporal lobe metabolism in mild cognitive impairment and Alzheimer's disease using FDG-PET

    Energy Technology Data Exchange (ETDEWEB)

    Mosconi, Lisa [New York University School of Medicine, Department of Psychiatry, New York, NY (United States); University of Florence, Department of Clinical Pathophysiology, Nuclear Medicine Unit, Florence (Italy); New York University School of Medicine, Center for Brain Health, New York, NY (United States); Santi, Susan De; Li, Yi; Li, Juan; Zhan, Jiong; Boppana, Madhu [New York University School of Medicine, Department of Psychiatry, New York, NY (United States); Tsui, Wai Hon; Leon, Mony J. de [New York University School of Medicine, Department of Psychiatry, New York, NY (United States); Nathan Kline Institute, Orangeburg, NY (United States); Pupi, Alberto [University of Florence, Department of Clinical Pathophysiology, Nuclear Medicine Unit, Florence (Italy)

    2006-02-01

    This study was designed to examine the utility of visual inspection of medial temporal lobe (MTL) metabolism in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD) using FDG-PET scans. Seventy-five subjects [27 normal controls (NL), 26 MCI, and 22 AD] with FDG-PET and MRI scans were included in this study. We developed a four-point visual rating scale to evaluate the presence and severity of MTL hypometabolism on FDG-PET scans. The visual MTL ratings were compared with quantitative glucose metabolic rate (MR{sub glc}) data extracted using regions of interest (ROIs) from the MRI-coregistered PET scans of all subjects. A standard rating evaluation of neocortical hypometabolism was also completed. Logistic regressions were used to determine and compare the diagnostic accuracy of the MTL and cortical ratings. For both MTL and cortical ratings, high intra- and inter-rater reliabilities were found (p values <0.001). The MTL rating was highly correlated with and yielded a diagnostic accuracy equivalent to the ROI MR{sub glc} measures (p values <0.001). The combination of MTL and cortical ratings significantly improved the diagnostic accuracy over the cortical rating alone, with 100% of AD, 77% of MCI, and 85% of NL cases being correctly identified. This study shows that the visual rating of MTL hypometabolism on PET is reliable, yields a diagnostic accuracy equal to the quantitative ROI measures, and is clinically useful and more sensitive than cortical ratings for patients with MCI. We suggest this method be further evaluated for its potential in the early diagnosis of AD. (orig.)

  13. Maximal metabolic rates during voluntary exercise, forced exercise, and cold exposure in house mice selectively bred for high wheel-running.

    Science.gov (United States)

    Rezende, Enrico L; Chappell, Mark A; Gomes, Fernando R; Malisch, Jessica L; Garland, Theodore

    2005-06-01

    Selective breeding for high wheel-running activity has generated four lines of laboratory house mice (S lines) that run about 170% more than their control counterparts (C lines) on a daily basis, mostly because they run faster. We tested whether maximum aerobic metabolic rates (V(O2max)) have evolved in concert with wheel-running, using 48 females from generation 35. Voluntary activity and metabolic rates were measured on days 5+6 of wheel access (mimicking conditions during selection), using wheels enclosed in metabolic chambers. Following this, V(O2max) was measured twice on a motorized treadmill and twice during cold-exposure in a heliox atmosphere (HeO2). Almost all measurements, except heliox V(O2max), were significantly repeatable. After accounting for differences in body mass (S running speeds on the treadmill. However, running speeds and V(O2max) during voluntary exercise were significantly higher in S lines. Nevertheless, S mice never voluntarily achieved the V(O2max) elicited during their forced treadmill trials, suggesting that aerobic capacity per se is not limiting the evolution of even higher wheel-running speeds in these lines. Our results support the hypothesis that S mice have genetically higher motivation for wheel-running and they demonstrate that behavior can sometimes evolve independently of performance capacities. We also discuss the possible importance of domestication as a confounding factor to extrapolate results from this animal model to natural populations.

  14. Estimating the Basal metabolic rate from fat free mass in individuals with motor complete spinal cord injury.

    Science.gov (United States)

    Chun, S M; Kim, H-R; Shin, H I

    2017-09-01

    Cross-sectional study. This study aimed to validate the existing basal metabolic rate (BMR) predictive equations that include fat free mass (FFM) as an independent variable and, based on the FFM assessment, to develop a new SCI population-specific equation. Outpatient clinic in a general hospital. Our study group was formed of 50 individuals with chronic motor complete SCI: 27 patients with tetraplegia and 23 with paraplegia. Both BMR and FFM values were measured by indirect calorimetry (IC) and the whole-body dual energy X-ray absorptiometry, respectively. The BMR values measured by IC were compared with the values estimated from the Cunningham equation. Multiple linear regression analysis was performed to develop a new FFM-based, BMR predictive equation. The mean value of BMR measured by IC was 1274.8 (s.d.=235.2) kcal day -1 . The intra-class correlation coefficient (ICC) between values measured by IC and estimated from the Cunningham equation was 0.845 and the limits of agreement ranged from -30.6 to 241.3 kcal. SCI population specific BMR predictive equation was developed; BMR (kcal day -1 )=24.5 × FFM (kg)+244.4. The newly developed equation showed ICC of 0.866 with the limits of agreement from -229.0 to 233.1 kcal day -1 . A considerable bias from the BMR values measured by IC was still observed, which warrants clinical consideration when applying FFM-based BMR prediction equations to individuals with SCI.

  15. Strong association between corticosterone levels and temperature-dependent metabolic rate in individual zebra finches

    NARCIS (Netherlands)

    Jimeno Revilla, Blanca; Hau, Michaela; Verhulst, Simon

    2017-01-01

    Glucocorticoid hormones (GCs) are often assumed to be indicators of stress. At the same time, one of their fundamental roles is to facilitate metabolic processes to accommodate changes in energetic demands. Although the metabolic function of GCs is thought to be ubiquitous across vertebrates, we are

  16. Obese Japanese adults with type 2 diabetes have higher basal metabolic rates than non-diabetic adults.

    Science.gov (United States)

    Miyake, Rieko; Ohkawara, Kazunori; Ishikawa-Takata, Kazuko; Morita, Akemi; Watanabe, Shaw; Tanaka, Shigeho

    2011-01-01

    Several cross-sectional studies in Pima Indians and Caucasians have indicated that obese individuals with type 2 diabetes have a higher basal metabolic rate (BMR) than healthy, obese individuals. However, no study has investigated this comparison in Japanese subjects, who are known to be susceptible to type 2 diabetes due to genetic characteristics. Thirty obese Japanese adults with pre-type 2 diabetes (n=7) or type 2 diabetes (n=13) or without diabetes (n=10) participated in this study. BMR was measured using indirect calorimetry. The relationships between residual BMR (calculated as measured BMR minus BMR adjusted for fat-free mass, fat mass, age, and sex) and biomarkers including fasting glucose, glycosylated hemoglobin (HbA(1c)), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-R), triglycerides, and free fatty acids were examined using Pearson's correlation. BMR in diabetic subjects adjusted for fat-free mass, fat mass, age, and sex was 7.1% higher than in non-diabetic subjects. BMR in diabetic subjects was also significantly (pBMR and fasting glucose (r=0.391, p=0.032). These results indicate that in the Japanese population, obese subjects with type 2 diabetes have higher BMR compared with obese non-diabetic subjects. The fasting glucose level may contribute to these differences.

  17. 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

  18. Prolonged non-metabolic heart rate variability reduction as a physiological marker of psychological stress in daily life

    NARCIS (Netherlands)

    Verkuil, B.; Brosschot, J.F.; Tollenaar, M.S.; Lane, R.D.; Thayer, J.F.

    2016-01-01

    BACKGROUND Prolonged cardiac activity that exceeds metabolic needs can be detrimental for somatic health. Psychological stress could result in such "additional cardiac activity." PURPOSE In this study, we examined whether prolonged additional reductions in heart rate variability (AddHRVr) can be

  19. 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

  20. Device for measuring flow rate in a nuclear reactor core

    International Nuclear Information System (INIS)

    Hamano, Jiro.

    1980-01-01

    Purpose: To always calculate core flow rate automatically and accurately in BWR type nuclear power plants. Constitution: Jet pumps are provided to the recycling pump and to the inside of the pressure vessel of a nuclear reactor. The jet pumps comprise a plurality of calibrated jet pumps for forcively convecting the coolants and a plurality of not calibrated jet pumps in order to cool the heat generated in the reactor core. The difference in the pressures between the upper and the lower portions in both of the jet pumps is measured by difference pressure transducers. Further, a thermo-sensitive element is provided to measure the temperature of recycling water at the inlet of the recycling pump. The output signal from the difference pressure transducer is inputted to a process computer, calculated periodically based on predetermined calculation equations, compensated for the temperature by a recycling water temperature signal and outputted as a core flow rate signal to a recoder. The signal is also used for the power distribution calculation in the process computer and the minimum limit power ratio as the thermal limit value for the fuels is outputted. (Furukawa, Y.)

  1. Lagrangian measurements of sulfur dioxide to sulfate conversion rates

    Energy Technology Data Exchange (ETDEWEB)

    Zak, B D

    1981-12-01

    On the basis of Project MISTT data and proposed homogenous gas phase oxidation mechanisms for sulfur dioxide, it has been suggested that the degree of mixing with background air, the chemical composition of the background air, and the intensity of the sunlight available are key factors determining the rate of sulfur dioxide to sulfate conversion. These hypotheses are examined in light of Lagrangian measrements of conversion rates in power plant plumes made during the Tennessee Plume Study and Project Da Vinci. It is found that the Lagrangian conversion rate measurements are consistent with these hypotheses. It has also been suggested that the concentration of ozone may serve as a workable surrogate for the concentrations of the free radicals involved in the homogeneous gas phase mechanism. The night-time Lagrangian data remind one that the gross difference in mean lifetime of ozone and free radicals can lead to situations in which the ozone concentration is not a good surrogate for the free radical concentrations.

  2. Use of the local false discovery rate for identification of metabolic biomarkers in rat urine following Genkwa Flos-induced hepatotoxicity.

    Directory of Open Access Journals (Sweden)

    Zuojing Li

    Full Text Available Metabolomics is concerned with characterizing the large number of metabolites present in a biological system using nuclear magnetic resonance (NMR and HPLC/MS (high-performance liquid chromatography with mass spectrometry. Multivariate analysis is one of the most important tools for metabolic biomarker identification in metabolomic studies. However, analyzing the large-scale data sets acquired during metabolic fingerprinting is a major challenge. As a posterior probability that the features of interest are not affected, the local false discovery rate (LFDR is a good interpretable measure. However, it is rarely used to when interrogating metabolic data to identify biomarkers. In this study, we employed the LFDR method to analyze HPLC/MS data acquired from a metabolomic study of metabolic changes in rat urine during hepatotoxicity induced by Genkwa flos (GF treatment. The LFDR approach was successfully used to identify important rat urine metabolites altered by GF-stimulated hepatotoxicity. Compared with principle component analysis (PCA, LFDR is an interpretable measure and discovers more important metabolites in an HPLC/MS-based metabolomic study.

  3. Bone metabolic activity in hyperostosis cranialis interna measured with {sup 18}F-fluoride PET

    Energy Technology Data Exchange (ETDEWEB)

    Waterval, Jerome J.; Dongen, Thijs M.A. van; Stokroos, Robert J.; Manni, Johannes J. [Maastricht University Medical Center, Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht (Netherlands); Teule, Jaap G.J.; Kemerink, Gerrit J.; Brans, Boudewijn [Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Nieman, Fred H.M. [Maastricht University Medical Center, Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht (Netherlands)

    2011-05-15

    {sup 18}F-Fluoride PET/CT is a relatively undervalued diagnostic test to measure bone metabolism in bone diseases. Hyperostosis cranialis interna (HCI) is a (hereditary) bone disease characterised by endosteal hyperostosis and osteosclerosis of the skull and the skull base. Bone overgrowth causes entrapment and dysfunction of several cranial nerves. The aim of this study is to compare standardised uptake values (SUVs) at different sites in order to quantify bone metabolism in the affected anatomical regions in HCI patients. Nine affected family members, seven non-affected family members and nine non-HCI non-family members underwent {sup 18}F-fluoride PET/CT scans. SUVs were systematically measured in the different regions of interest: frontal bone, sphenoid bone, petrous bone and clivus. Moreover, the average {sup 18}F-fluoride uptake in the entire skull was measured by assessing the uptake in axial slides. Visual assessment of the PET scans of affected individuals was performed to discover the process of disturbed bone metabolism in HCI. {sup 18}F-Fluoride uptake is statistically significantly higher in the sphenoid bone and clivus regions of affected family members. Visual assessment of the scans of HCI patients is relevant in detecting disease severity and the pattern of disturbed bone metabolism throughout life. {sup 18}F-Fluoride PET/CT is useful in quantifying the metabolic activity in HCI and provides information about the process of disturbed bone metabolism in this specific disorder. Limitations are a narrow window between normal and pathological activity and the influence of age. This study emphasises that {sup 18}F-fluoride PET/CT may also be a promising diagnostic tool for other metabolic bone disorders, even those with an indolent course. (orig.)

  4. Bone metabolic activity in hyperostosis cranialis interna measured with 18F-fluoride PET

    International Nuclear Information System (INIS)

    Waterval, Jerome J.; Dongen, Thijs M.A. van; Stokroos, Robert J.; Manni, Johannes J.; Teule, Jaap G.J.; Kemerink, Gerrit J.; Brans, Boudewijn; Nieman, Fred H.M.

    2011-01-01

    18 F-Fluoride PET/CT is a relatively undervalued diagnostic test to measure bone metabolism in bone diseases. Hyperostosis cranialis interna (HCI) is a (hereditary) bone disease characterised by endosteal hyperostosis and osteosclerosis of the skull and the skull base. Bone overgrowth causes entrapment and dysfunction of several cranial nerves. The aim of this study is to compare standardised uptake values (SUVs) at different sites in order to quantify bone metabolism in the affected anatomical regions in HCI patients. Nine affected family members, seven non-affected family members and nine non-HCI non-family members underwent 18 F-fluoride PET/CT scans. SUVs were systematically measured in the different regions of interest: frontal bone, sphenoid bone, petrous bone and clivus. Moreover, the average 18 F-fluoride uptake in the entire skull was measured by assessing the uptake in axial slides. Visual assessment of the PET scans of affected individuals was performed to discover the process of disturbed bone metabolism in HCI. 18 F-Fluoride uptake is statistically significantly higher in the sphenoid bone and clivus regions of affected family members. Visual assessment of the scans of HCI patients is relevant in detecting disease severity and the pattern of disturbed bone metabolism throughout life. 18 F-Fluoride PET/CT is useful in quantifying the metabolic activity in HCI and provides information about the process of disturbed bone metabolism in this specific disorder. Limitations are a narrow window between normal and pathological activity and the influence of age. This study emphasises that 18 F-fluoride PET/CT may also be a promising diagnostic tool for other metabolic bone disorders, even those with an indolent course. (orig.)

  5. Intra-abdominal fat measurement by ultrasonography: association with anthropometry and metabolic syndrome in adolescents.

    Science.gov (United States)

    Novais, Rommel L R; Café, Ana Carolina C; Morais, Aisha A; Bila, Wendell C; Santos, Gilson D da S; Lopes, Carlos Alexandre de O; Belo, Vinícius S; Romano, Márcia Christina C; Lamounier, Joel A

    2018-04-27

    To associate intra-abdominal fat thickness measured by ultrasonography to the factors related to metabolic syndrome and to determine cutoff points of intra-abdominal fat measurement associated with a greater chance of metabolic syndrome in adolescents. This was a cross-sectional study, with 423 adolescents from public schools. Intra-abdominal fat was measured by ultrasonography. Anthropometric data were collected, and biochemical analyses were performed. Intra-abdominal fat was measured by ultrasonography, showing a statistically significant association with the diagnosis of metabolic syndrome (p=0.037), body mass index (p<0.001), elevated triglyceride levels (p=0.012), decreased plasma HDL levels (p=0.034), and increased systemic blood pressure values (p=0.023). Cutoff values of intra-abdominal fat thickness measurements were calculated by ultrasound to estimate the individuals most likely to develop metabolic syndrome. In the logistic regression models, the cutoff values that showed the highest association with metabolic syndrome in males were 4.50, 5.35, 5.46, 6.24, and 6.50cm for the ages of 14, 15, 16, 17, and 18/19 years, respectively. In the female gender, the cutoff values defined for the same age groups were 4.46, 4.55, 4.45, 4.90, and 6.46cm. In an overall analysis using the ROC curve, without gender and age stratification, the cut-off of 3.67cm showed good sensitivity, but low specificity. Ultrasonography is a useful method to estimate intra-abdominal adipose tissue in adolescents, which is associated with the main factors related to obesity and metabolic syndrome. Copyright © 2018 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  6. Variability in the measurement of hospital-wide mortality rates.

    Science.gov (United States)

    Shahian, David M; Wolf, Robert E; Iezzoni, Lisa I; Kirle, Leslie; Normand, Sharon-Lise T

    2010-12-23

    Several countries use hospital-wide mortality rates to evaluate the quality of hospital care, although the usefulness of this metric has been questioned. Massachusetts policymakers recently requested an assessment of methods to calculate this aggregate mortality metric for use as a measure of hospital quality. The Massachusetts Division of Health Care Finance and Policy provided four vendors with identical information on 2,528,624 discharges from Massachusetts acute care hospitals from October 1, 2004, through September 30, 2007. Vendors applied their risk-adjustment algorithms and provided predicted probabilities of in-hospital death for each discharge and for hospital-level observed and expected mortality rates. We compared the numbers and characteristics of discharges and hospitals included by each of the four methods. We also compared hospitals' standardized mortality ratios and classification of hospitals with mortality rates that were higher or lower than expected, according to each method. The proportions of discharges that were included by each method ranged from 28% to 95%, and the severity of patients' diagnoses varied widely. Because of their discharge-selection criteria, two methods calculated in-hospital mortality rates (4.0% and 5.9%) that were twice the state average (2.1%). Pairwise associations (Pearson correlation coefficients) of discharge-level predicted mortality probabilities ranged from 0.46 to 0.70. Hospital-performance categorizations varied substantially and were sometimes completely discordant. In 2006, a total of 12 of 28 hospitals that had higher-than-expected hospital-wide mortality when classified by one method had lower-than-expected mortality when classified by one or more of the other methods. Four common methods for calculating hospital-wide mortality produced substantially different results. This may have resulted from a lack of standardized national eligibility and exclusion criteria, different statistical methods, or

  7. Measuring Effective Tax Rates for Oil and Gas in Canada

    Directory of Open Access Journals (Sweden)

    Jack M. Mintz

    2010-03-01

    Full Text Available The purpose of this report is to provide cost of capital formulae for assessing the effects of taxation on the incentive to invest in oil and gas industries in Canada. The analysis is based on the assumption that businesses invest in capital until the after-tax rate of return on capital is equal to the tax-adjusted cost of capital. The cost of capital in absence of taxation is the inflation-adjusted cost of finance. The after-tax rate of return on capital is the annualized profit earned on a project net of the taxes paid by the businesses. For this purpose, we include corporate income, sales and other capital-related taxes as applied to oil and gas investments. For oil and gas taxation, it is necessary to account for royalties in a special way. Royalties are payment made by businesses for the right to extract oil and gas from land owned by the property holder. The land is owned by the province so the royalties are a rental payment for the benefit received from extracting the product from provincial lands. Thus, provincial royalty payments are a cost to oil and gas companies for using public property. However, since the provincial government is responsible for the royalty regime and could use taxes like the corporate income tax to extract revenue, one might think of royalties as part of the overall fiscal regime to raise revenue. In principle, one should subtract the rental benefit received from oil and gas businesses from taxes and royalty payments to assess the overall fiscal impact. This is impossible to do without measuring some explicit rental rate for use of provincial property. Further, royalty payments may distort economic decisions unlike a payment based on the economic rents earned on oil and gas projects. Instead, for comparability across jurisdictions, one might calculate the aggregate tax and royalty effective tax rates (such as between Alberta and Texas.

  8. Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

    International Nuclear Information System (INIS)

    Anazodo, Udunna; Kewin, Matthew; Finger, Elizabeth; Thiessen, Jonathan; Hadway, Jennifer; Butler, John; Pavlosky, William; Prato, Frank; Thompson, Terry; St Lawrence, Keith

    2015-01-01

    PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

  9. Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Anazodo, Udunna; Kewin, Matthew [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Finger, Elizabeth [Department of Clinical Neurological Sciences, Western University, London, Ontario (Canada); Thiessen, Jonathan; Hadway, Jennifer; Butler, John [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Pavlosky, William [Diagnostic Imaging, St Joseph' s Health Care, London, Ontario (Canada); Prato, Frank; Thompson, Terry; St Lawrence, Keith [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada)

    2015-05-18

    PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

  10. [Study of Basal metabolic rate of 81 young adults aged 20-29 years old in Changsha].

    Science.gov (United States)

    Zhou, X; Mao, D Q; Luo, J Y; Wu, J H; Zhuo, Q; Li, Y M

    2017-07-06

    Objective: To determine the basal metabolic rate (BMR) of young adults aged between 20-29 years old in Changsha. Methods: We recruited volunteers to join in our research project from April to May, 2015. All recruited volunteers must meet the inclusion criteria: aged 20-29 years old, height between 164-180 centimeters in males and 154-167 centimeters in females, in good health condition, and with no habit of regular physical exercise in last year. Finally, 81 qualified volunteers were selected as research objects, including 43 males and 38 females. The BMR, resting lying metabolism rate and resting sitting metabolism rate of the subjects were detected, and the determined BMR was compared with the calculated results: from the adjusted Schofield equation. Results The BMR, resting lying metabolism rate and resting sitting metabolism rate among males were (166.10±22.09), (174.22±24.56), and (179.54±23.35) kJ·m(-2)·h(-1), respectively, which were all higher than those among females were (137.70±20.04), (149.79±19.25), and (167.78±26.02) kJ·m(-2)·h(-1), respectively, ( PBMR of males and females calculated from the adjusted Schofield equation were (160.83±3.93), and (140.29±4.18) kJ·m(-2)·h(-1), respectively, and there was no significantly statistical difference found between the determined BMR and the calculated results from Schofield equation (adjusted) classified by sex, all P values >0.05. Conclusion: The BMR of young adults aged 20-29 years old in Changsha was in the national average level, and the adjusted Schofield equation displayed fine accuracy in predicting BMR of young adults aged 20-29 years old in Changsha.

  11. The measurement of the nigrostriatal dopaminergic function and glucose metabolism in patients with movement disorders

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Makoto; Ichiya, Yuichi; Kuwabara, Yasuo; Sasaki, Masayuki; Fukumura, Toshimitsu; Masuda, Kouji; Shima, Fumio; Kato, Motohiro (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-12-01

    The nigrostriatal dopaminergic function and glucose metabolism were evaluated in 34 patients with various movement disorders by using positron emission tomography with [sup 18]F-Dopa and [sup 18]F-FDG respectively. The [sup 18]F-Dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The [sup 18]F-Dopa uptake in the striatum also decreased in cases of atypical parkinsonism and in cases of progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral hemisphere including the striatum; this finding was also different from those of Parkinson's disease. A normal [sup 18]F-Dopa uptake in the striatum with a markedly decreased striatal glucose metabolism and a mildly decreased cortical glucose metabolism was observed in cases of Huntington's disease and Wilson's disease. The [sup 18]F-Dopa uptake in the striatum increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of [sup 18]F-Dopa uptake and glucose metabolism were thus observed in the various movement disorders. These results suggest that the measurements of the [sup 18]F-Dopa uptake and the cerebral glucose metabolism would be useful for the evaluation of the striatal function in various movement disorders. (author).

  12. Vadose Zone Infiltration Rates from Sr isotope Measurements

    Science.gov (United States)

    Maher, K.; Maher, K.; DePaolo, D. J.; DePaolo, D. J.; Conrad, M.

    2001-12-01

    Predicting infiltration rates and recharge through the vadose zone in arid regions is difficult and hence developing methods for the measurement of infiltration rates is important. We have been investigating the use of Sr isotope measurements for determining infiltration at the 200 Area plateau on the Hanford reservation in central Washington. In this context, infiltration affects the transport of contaminants to the water table as well as recharge of the groundwater system. Using Sr isotopes for this purpose requires drill core and water samples from the vadose zone, although leaches of the cores can substitute for water samples. Complementary information, including some constraints on regional recharge, can also be obtained using water samples from groundwater monitoring wells. The VZ method is based on the fact that the Sr isotope ratio of soil water just below the surface is often set by dissolution of aeolian material including carbonate, and this ratio is different from the average value in the deeper underlying vadose zone rock matrix. As water infiltrates, the Sr isotopic composition of the water changes toward the rock values as a result of Sr released from the rocks by weathering reactions. The rate of change with depth of the Sr isotope ratio of the vadose zone water is a function ultimately of q/R; the ratio of the infiltration flux (q) to the bulk rock weathering rate (R). Where it is possible to evaluate R, q can be estimated. As data accumulate it may be possible to improve the calibration of the method. At Hanford the vadose zone rock material is mostly unconsolidated sand, silt, and gravel of broadly granitic composition, which constitute the Hanford and Ringold formations. Annual precipitation is about 160 mm/yr. Drilling and coring of a ca. 70m hole to the water table in 1999 as part of the Hanford groundwater monitoring program, in a relatively undisturbed area of the site, allowed us to generate a unique Sr isotope data set. The Sr isotope

  13. In vivo 31P-NMR studies on the energy metabolism of atrophic muscles in rate

    International Nuclear Information System (INIS)

    Yamagiwa, Tetsuo

    1988-01-01

    Using P-31 NMR spectra, energy metabolism in the rat calf muscle was examined. The body weight in the atrophy and control groups did not differ significantly. Both the wet weight and dry weight of the calf muscle were significantly lower in the atrophy group than the control group. The muscle weight relative to the body weight was significantly lower in the atrophy group as well than the control group. There was no significant difference in the P-31 NMR spectral pattern before tourniquet ischemia between the atrophy and control groups. Rapid decrease in phosphocreatine (PCr) and rapid increase in inorganic phosphate (Pi) were observed in both groups immediately after application of the tourniquet; however, the rates of these changes were slightly greater and the PCr/Pi ratio in the peak values was significantly smaller in the atrophy group than the control group. The pH value before the ischemia was 7.15 ± 0.02 for the control group and 7.16 ± 0.02 for the atrophy group, with no significant difference between the groups. During ischemia, the pH value decreased progressively in the two groups; however, it became significantly decreased in the atrophy group from 10 to 60 min after application of tourniquet. The decrease in pH became gradual 60 min later. Since the decrease in pH was more rapid in the atrophic muscle than the intact muscle, this buffering capacity seems to be reduced in the atrophic muscle. (N.K.)

  14. Glucose metabolism of fetal rat brain in utero, measured with labeled deoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Dyve, S [Department of General Physiology and Biophysics, Panum Institute, Copenhagen (Denmark); Gjedde, A [Positron Imaging Laboratories, McConnell Brain Imaging Center, Montreal, Quebec (Canada)

    1991-01-01

    Mammals have low cerebral metabolic rates immediately after birth and, by inference, also before birth. In this study, we extended the deoxyglucose method to the fetal rat brain in utero. Rate constants for deoxyglucose transfer across the maternal placental and fetal blood-brain barriers, and lumped constant, have not been reported. Therefore, we applied a new method of determining the lumped constant regionally to the fetal rat brain in utero. The lumped constant averaged 0.55 +- 0.15 relative to the maternal circulation. On this basis, we determined the glucose metabolic rate of the fetal rat brain to be one third of the corresponding maternal value, or 19 +- 2 {mu}mol hg{sup -1} min{sup -1}. (author).

  15. [Primary study on characteristics of insulin secretion rate, metabolic clearance rate and sensitivity in non-insulin-dependent diabetic subjects from multiplex diabetic pedigrees].

    Science.gov (United States)

    Ran, J; Cheng, H; Li, F

    2000-01-01

    To investigate the characteristics of insulin secretion rate (ISR), metabolic clearance rate (MCR-I) and sensitivity and to explore their relationship with obesity in non-insulin-dependent diabetic subjects from multiplex diabetic pedigrees (MDP). Fifteen subjects with normal glucose tolerance and 11 non-insulin-dependent diabetic patients from MDP were included in the study. Frequently sampled intravenous glucose tolerance test (FSIVGTT) was performed. Glucose, insulin (INS) and connecting-peptide (C-P) concentrations were measured. A computer procedure devised by our laboratory was used to calculate the value of ISR at each time point, then MCR-I was acquired. Insulin sensitivity index (SI) was calculated according to minimal model technique about glucose in FSIVGTT. The ISR curve in control group was biphasic, while in non-insulin. In non-insulin-dependent diabetic group, areas under the curves of C-P (AUCC) and ISR level (AUCS) measured during 0 approximately 16 min were 7.9 nmol.min(-1).L(-1) +/- 2.8 nmol.min(-1).L(-1), and 6.1 nmol +/- 2.2 nmol, respectively, which were significantly lower than those in control group 17.7 nmol.min(-1).L(-1) +/- 4.92 nmol.min(-1).L(-1) and 12.3 nmol +/- 3.9 nmol (P < 0.01). The two parameters were slightly higher than those in control group 155 nmol.min(-1).L(-1) +/- 44 nmol.min(-1).L(-1) vs 101 nmol.min(-1).L(-1) +/- 30 nmol.min(-1).L(-1) and 76 nmol +/- 26 nmol vs 54 nmol +/- 20.0 nmol (P < 0.05)measured during 16 approximately 180 min. There was no significant difference, between the two groups about the amount of insulin secretion during 3 hours (82 nmol +/- 28nmol vs 68 nmol +/- 21 nmol, P = 0.2). In control group, there were significant positive correlation, between AUCS, waist-hip ratio (WHR), and body surface area, (BSA) and significant negative correlation between MCR-I, SI and WHR, BSA (P < 0.01), and also between MCR-I and SI. In non-insulin-dependent diabetic group, AUCS were significantly correlated with body mass

  16. Radiation dosemeters and ambient dose rate measuring systems

    International Nuclear Information System (INIS)

    Maushart, R.

    1985-01-01

    The manufacturers have got the feeling that the PTB only reluctantly accepts complex dosimetric systems or systems with modern digital and microprocessor technology. Especially the fact that the PTB demands a restriction to a defined system configuration which must not be changed after design approval is felt to be a severe handicap. The rigid frame of design qualification forces manufacturers to adopt a two-tier development line, at least for ambient dose rate measuring systems, and frequently it is not necessarily the 'nature' system, i.e. equipment with modern technology, that is sent in to the PTB for testing. The way of solving the problem could be that PTB more readily accepts less familiar technologies, for instance by more frequently approving equipment at least preliminarily or for a restricted period of time, in order to collect experience. Another way could be to grant licence for system components, especially detectors. (orig./HP) [de

  17. Standard test method for measurement of fatigue crack growth rates

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    1.1 This test method covers the determination of fatigue crack growth rates from near-threshold to Kmax controlled instability. Results are expressed in terms of the crack-tip stress-intensity factor range (ΔK), defined by the theory of linear elasticity. 1.2 Several different test procedures are provided, the optimum test procedure being primarily dependent on the magnitude of the fatigue crack growth rate to be measured. 1.3 Materials that can be tested by this test method are not limited by thickness or by strength so long as specimens are of sufficient thickness to preclude buckling and of sufficient planar size to remain predominantly elastic during testing. 1.4 A range of specimen sizes with proportional planar dimensions is provided, but size is variable to be adjusted for yield strength and applied force. Specimen thickness may be varied independent of planar size. 1.5 The details of the various specimens and test configurations are shown in Annex A1-Annex A3. Specimen configurations other than t...

  18. Measuring hand hygiene compliance rates at hospital entrances.

    Science.gov (United States)

    Vaidotas, Marina; Yokota, Paula Kiyomi Onaga; Marra, Alexandre R; Camargo, Thiago Zinsly Sampaio; Victor, Elivane da Silva; Gysi, Deisy Morselli; Leal, Flavio; Santos, Oscar Fernando Pavão dos; Edmond, Michael B

    2015-07-01

    Despite the importance of hand hygiene in the health care setting, there are no studies evaluating hand hygiene compliance at hospital entrances. The study was prospectively performed over a 33-week period from March 30, 2014-November 15, 2014, to evaluate hand hygiene compliance in 2 hospital reception areas. We compared electronic handwash counters with the application of radiofrequency identification (GOJO SMARTLINK) (electronic observer) that counts each activation of alcohol gel dispensers to direct observation (human observer) via remote review of video surveillance. We found low hand hygiene compliance rates of 2.2% (99/4,412) and 1.7% (140/8,277), respectively, at reception areas A and D, detected by direct observation. Using the electronic observer, we measured rates of 17% (15,624/91,724) and 7.1% (51,605/730,357) at reception areas A and D, respectively. For the overall time period of simultaneous electronic and human observation, the human observer captured 1% of the hand hygiene episodes detected by the electronic observer. Our study showed very low hand hygiene compliance in hospital reception areas, and we found an electronic hand hygiene system to be a useful method to monitor hand hygiene compliance. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  19. 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

  20. Cortisol production rates measured by liquid chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Esteban, N.V.; Yergey, A.L.

    1990-01-01

    Cortisol production rates (FPRs) in physiologic and pathologic states in humans have been investigated over the past 30 years. However, there has been conflicting evidence concerning the validity of the currently accepted value of FPRs in humans (12 to 15 mg/m2/d) as determined by radiotracer methodology. The present study reviews previous methods proposed for the measurement of FPRs in humans and discusses the applications of the first method for the direct determination of 24-hour plasma FPRs during continuous administration of a stable isotope, using a thermospray high-pressure liquid chromatography-mass spectrometry technique. The technique is fast, sensitive, and, unlike gas chromatography-mass spectrometry methods, does not require derivatization, allowing on-line detection and quantification of plasma cortisol after a simple extraction procedure. The results of determination of plasma FPRs by stable tracer/mass spectrometry are directly in units of mass/time and, unlike radiotracer methods, are independent of any determination of volume of distribution or cortisol concentration. Our methodology offers distinct advantages over radiotracer techniques in simplicity and reliability since only single measurements of isotope ratios are required. The technique was validated in adrenalectomized patients. Circadian variations in daily FRPs were observed in normal volunteers, and, to date, results suggest a lower FRP in normal children and adults than previously believed. 88 references

  1. Differential measurement of low level HTO and HT leak rates

    International Nuclear Information System (INIS)

    Sheehan, W.E.; Muldoon, K.M.

    1976-08-01

    Leak rates of 5 x 10 -17 cm 3 /sec and greater can be measured by a very simple technique that will also differentiate tritium oxide (HTO) from tritium gas (HT). Because of the much greater health hazard of tritium oxide (200 to 1), the determination of chemical form is significant. The method involves flushing a gas collection chamber, containing the item being measured, with dry air. The flushed air is passed through an ethylene glycol bubbler which removes only the HTO. The outlet of the ethylene glycol bubbler is connected to a heated (400 0 C) palladium sponge catalyst which converts the HT to HTO and then to a second ethylene glycol bubbler for collection of the oxidized tritium gas. Liquid scintillation (p-dioxane base) counting solution is added directly to the bubblers and counted for tritium in a Liquid Scintillation Spectrometer. Advantages, method validation, operational experience, and data obtained by this technique are discussed. The sensitivity of the method is dependent on the time allowed between bubbler changes, the liquid scintillation spectrometer counting efficiency, background, and counting times employed

  2. Can We Rely on Predicted Basal Metabolic Rate in Patients With Intestinal Failure on Home Parenteral Nutrition?

    Science.gov (United States)

    Skallerup, Anders; Nygaard, Louis; Olesen, Søren Schou; Vinter-Jensen, Lars; Køhler, Marianne; Rasmussen, Henrik Højgaard

    2017-09-01

    Intestinal failure (IF) is a serious and common complication of short bowel syndrome with patients depending on parenteral nutrition (PN) support. Effective nutrition management requires an accurate estimation of the patient's basal metabolic rate (BMR) to avoid underfeeding or overfeeding. However, indirect calorimetry, considered the gold standard for BMR assessment, is a time- and resource-consuming procedure. Consequently, several equations for prediction of BMR have been developed in different settings, but their accuracy in patients with IF are yet to be investigated. We evaluated the accuracy of predicted BMR in clinically stable patients with IF dependent on home parenteral nutrition (HPN). 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 and/or bioelectrical impedance parameters. The accuracy of predicted BMR was evaluated using Bland-Altman analysis with measured BMR as the gold standard. The average measured BMR was 1272 ± 245 kcal/d. The most accurate estimations of BMR were obtained using the Harris-Benedict equation (mean bias, 14 kcal/d [ P = .28]; limits of agreement [LoA], -238 to 266 kcal/d) and the Johnstone equation (mean bias, -16 kcal/d [ P = .24]; LoA, -285 to 253 kcal/d). For both equations, 67% of patients had a predicted BMR from 90%-110% All other equations demonstrated a statistically and clinically significant difference between measured and predicted BMR. The Harris-Benedict and Johnstone equations reliably predict BMR in two-thirds of clinically stable patients with IF on HPN.

  3. Smaller size of high metabolic rate organs explains lower resting energy expenditure in Asian-Indian Than Chinese men.

    Science.gov (United States)

    Song, L L T; Venkataraman, K; Gluckman, P; Chong, Y S; Chee, M-W L; Khoo, C M; Leow, M-Ks; Lee, Y S; Tai, E S; Khoo, E Y H

    2016-04-01

    In Singapore, the obesity prevalence is disproportionately higher in the Asian-Indians and Malays than the Chinese. Lower resting energy expenditure (REE) may be a contributory factor. We explored the association between ethnicity and REE in Chinese, Asian-Indian and Malay men living in Singapore and determined the influence of body composition, mass/volume of high metabolic rate organs, represented by brain volume and trunk fat-free mass (FFM), and physical activity on ethnic differences. Two hundred and forty-four men from Singapore (n=100 Chinese, 70 Asian-Indians and 74 Malays), aged 21-40 years and body mass index of 18.5-30.0 kg m(-2), were recruited in this cross-sectional study. REE was assessed by indirect calorimetry and body composition by dual-energy X-ray absorptiometry. Brain volume was measured by magnetic resonance imaging. Physical activity was assessed by the Singapore Prospective Study Program Physical Activity Questionnaire. REE was significantly lower in Asian-Indians compared with that in Chinese after adjusting for body weight. FFM (total, trunk and limb) and total fat mass were important predictors of REE across all ethnic groups. Brain volume was positively associated with REE only in Malays. Moderate and vigorous physical activity was positively associated with REE only in Asian-Indians and Malays. The difference in REE between Asian-Indians and Chinese was attenuated but remained statistically significant after adjustment for total FFM (59±20 kcal per day), fat mass (67±20 kcal per day) and brain volume (54±22 kcal per day). The association between REE and ethnicity was no longer statistically significant after total FFM was replaced by trunk FFM (which includes heart, liver, kidney and spleen) but not when it was replaced by limb FFM (skeletal muscle). We have demonstrated a lower REE in Asian-Indians compared with Chinese who may contribute to the higher rates of obesity in the former. This difference could be accounted for

  4. One-carbon metabolism, cognitive impairment and CSF measures of Alzheimer pathology: homocysteine and beyond.

    Science.gov (United States)

    Dayon, Loïc; Guiraud, Seu Ping; Corthésy, John; Da Silva, Laeticia; Migliavacca, Eugenia; Tautvydaitė, Domilė; Oikonomidi, Aikaterini; Moullet, Barbara; Henry, Hugues; Métairon, Sylviane; Marquis, Julien; Descombes, Patrick; Collino, Sebastiano; Martin, François-Pierre J; Montoliu, Ivan; Kussmann, Martin; Wojcik, Jérôme; Bowman, Gene L; Popp, Julius

    2017-06-17

    Hyperhomocysteinemia is a risk factor for cognitive decline and dementia, including Alzheimer disease (AD). Homocysteine (Hcy) is a sulfur-containing amino acid and metabolite of the methionine pathway. The interrelated methionine, purine, and thymidylate cycles constitute the one-carbon metabolism that plays a critical role in the synthesis of DNA, neurotransmitters, phospholipids, and myelin. In this study, we tested the hypothesis that one-carbon metabolites beyond Hcy are relevant to cognitive function and cerebrospinal fluid (CSF) measures of AD pathology in older adults. Cross-sectional analysis was performed on matched CSF and plasma collected from 120 older community-dwelling adults with (n = 72) or without (n = 48) cognitive impairment. Liquid chromatography-mass spectrometry was performed to quantify one-carbon metabolites and their cofactors. Least absolute shrinkage and selection operator (LASSO) regression was initially applied to clinical and biomarker measures that generate the highest diagnostic accuracy of a priori-defined cognitive impairment (Clinical Dementia Rating-based) and AD pathology (i.e., CSF tau phosphorylated at threonine 181 [p-tau181]/β-Amyloid 1-42 peptide chain [Aβ 1-42 ] >0.0779) to establish a reference benchmark. Two other LASSO-determined models were generated that included the one-carbon metabolites in CSF and then plasma. Correlations of CSF and plasma one-carbon metabolites with CSF amyloid and tau were explored. LASSO-determined models were stratified by apolipoprotein E (APOE) ε4 carrier status. The diagnostic accuracy of cognitive impairment for the reference model was 80.8% and included age, years of education, Aβ 1-42 , tau, and p-tau181. A model including CSF cystathionine, methionine, S-adenosyl-L-homocysteine (SAH), S-adenosylmethionine (SAM), serine, cysteine, and 5-methyltetrahydrofolate (5-MTHF) improved the diagnostic accuracy to 87.4%. A second model derived from plasma included cystathionine

  5. High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising cardiac function in sedentary aging men.

    Science.gov (United States)

    Grace, Fergal; Herbert, Peter; Elliott, Adrian D; Richards, Jo; Beaumont, Alexander; Sculthorpe, Nicholas F

    2017-05-13

    This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Using a STROBE compliant observational design, 39 aging male participants (SED; n=22, aged 62.7±5.2yrs) (LEX; n=17, aged=61.1±5.4yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each PHIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (PHIIT. A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Non-invasive measurement of brain glycogen by NMR spectroscopy and its application to the study of brain metabolism

    Science.gov (United States)

    Tesfaye, Nolawit; Seaquist, Elizabeth R.; Öz, Gülin

    2011-01-01

    Glycogen is the reservoir for glucose in the brain. Beyond the general agreement that glycogen serves as an energy source in the central nervous system, its exact role in brain energy metabolism has yet to be elucidated. Experiments performed in cell and tissue culture and animals have shown that glycogen content is affected by several factors including glucose, insulin, neurotransmitters, and neuronal activation. The study of in vivo glycogen metabolism has been hindered by the inability to measure glycogen non-invasively, but in the past several years, the development of a non-invasive localized 13C nuclear magnetic resonance (NMR) spectroscopy method has enabled the study of glycogen metabolism in the conscious human. With this technique, 13C-glucose is administered intravenously and its incorporation into and wash-out from brain glycogen is tracked. One application of this method has been to the study of brain glycogen metabolism in humans during hypoglycemia: data have shown that mobilization of brain glycogen is augmented during hypoglycemia and, after a single episode of hypoglycemia, glycogen synthesis rate is increased, suggesting that glycogen stores rebound to levels greater than baseline. Such studies suggest glycogen may serve as a potential energy reservoir in hypoglycemia and may participate in the brain's adaptation to recurrent hypoglycemia and eventual development of hypoglycemia unawareness. Beyond this focused area of study, 13C NMR spectroscopy has a broad potential for application in the study of brain glycogen metabolism and carries the promise of a better understanding of the role of brain glycogen in diabetes and other conditions. PMID:21732401

  7. Measuring Glial Metabolism in Repetitive Brain Trauma and Alzheimer’s Disease

    Science.gov (United States)

    2016-09-01

    stages of repetitive brain trauma as well. Current methods of measure brain glutamate using proton spectroscopy is not specific to different cell...covering a representative range of clinical cases: a young female , young male , middle-aged male (all healthy volunteers) and a male patient with...AWARD NUMBER: W81XWH-15-1-0412 TITLE: Measuring Glial Metabolism in Repetitive Brain Trauma and Alzheimer’s Disease PRINCIPAL INVESTIGATOR

  8. Flow cytometric measurement of the metabolism of benzo [a] pyrene by mouse liver cells in culture

    International Nuclear Information System (INIS)

    Bartholomew, J.C.; Wade, C.G.; Dougherty, K.

    1984-01-01

    The metabolism of benzo[a]pyrene in individual cells was monitored by flow cytometry. The measurements are based on the alterations that occur in the fluorescence emission spectrum of benzo[a]pyrene when it is converted to various metabolities. Using present instrumentation the technique could easily detect 1 x 10/sup 6/ molecules per cells of benzo [a]pyrene and 1 x 10/sup 7/ molecules per cell of the diol epoxide. The analysis of C3H IOT 1/2 mouse fibroblasts growing in culture indicated that there was heterogeneity in the conversion of the parent compound into diol epoxide derivative suggesting that some variation in sensitivity to transformation by benzo[a]pyrene may be due to differences in cellular metabolism

  9. Physiological response to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups: metabolic rates, energy reserve utilization, and water fluxes.

    Science.gov (United States)

    Verrier, Delphine; Groscolas, René; Guinet, Christophe; Arnould, John P Y

    2009-11-01

    Surviving prolonged fasting requires various metabolic adaptations, such as energy and protein sparing, notably when animals are simultaneously engaged in energy-demanding processes such as growth. Due to the intermittent pattern of maternal attendance, subantarctic fur seal pups have to repeatedly endure exceptionally long fasting episodes throughout the 10-mo rearing period while preparing for nutritional independence. Their metabolic responses to natural prolonged fasting (33.4 +/- 3.3 days) were investigated at 7 mo of age. Within 4-6 fasting days, pups shifted into a stage of metabolic economy characterized by a minimal rate of body mass loss (0.7%/day) and decreased resting metabolic rate (5.9 +/- 0.1 ml O(2)xkg(-1)xday(-1)) that was only 10% above the level predicted for adult terrestrial mammals. Field metabolic rate (289 +/- 10 kJxkg(-1)xday(-1)) and water influx (7.9 +/- 0.9 mlxkg(-1)xday(-1)) were also among the lowest reported for any young otariid, suggesting minimized energy allocation to behavioral activity and thermoregulation. Furthermore, lean tissue degradation was dramatically reduced. High initial adiposity (>48%) and predominant reliance on lipid catabolism likely contributed to the exceptional degree of protein sparing attained. Blood chemistry supported these findings and suggested utilization of alternative fuels, such as beta-hydroxybutyrate and de novo synthesized glucose from fat-released glycerol. Regardless of sex and body condition, pups tended to adopt a convergent strategy of extreme energy and lean body mass conservation that appears highly adaptive for it allows some tissue growth during the repeated episodes of prolonged fasting they experience throughout their development.

  10. Evaluation of heart rate reserve and high-sensitivity C-reactive protein in individuals with and without metabolic syndrome in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Yosef Khaledi

    2012-06-01

    Full Text Available    BACKGROUND: Lack of heart rate increase proportionate to exercise causes poor prognosis. Moreover, inflammatory factors such as C-reactive protein (CRP are associated with atherosclerosis. The current study compared these two indices in individuals with and without metabolic syndrome in Isfahan, Iran.    METHODS: This study was performed on 203 people without and 123 patients with metabolic syndrome who were randomly selected from the participants of the Isfahan Cohort Study. The demographic data, waist circumference, blood pressure, height, and weight of the participants were recorded. Moreover, serum triglyceride (TG, fasting blood sugar (FBS, total cholesterol, high density lipoprotein (HDL, low density lipoprotein (LDL, and high-sensitivity CRP (hs-CRP levels were measured. Exercise test was carried out according to the Bruce standard protocol and heart rate reserve (HRR was determined and recorded. The age-adjusted data was analyzed using generalized linear regression and student's t-test in SPSS15.    RESULTS: The mean ages of participants without and with metabolic syndrome were 54.16 ± 8.61 and 54.29 ± 7.6 years, respectively. The corresponding values for mean LDL levels were 116.17 ± 24.04 and 120.12 ± 29.55 mg/dl. TG levels were 140.38 ± 61.65 and 259.99 ± 184.49 mg/dl for subjects without and with the metabolic syndrome, respectively. The mean FBS levels were 81.81 ± 9.90 mg/dl in the participants without the syndrome and 107.13 ± 48.46 mg/dl in those with metabolic syndrome. The mean systolic blood pressure was 116.06 ± 13.69 mmHg in persons without metabolic syndrome and 130.73 ± 15.15 mmHg in patients with the syndrome. The values for mean diastolic levels in the two groups were 76.52 ± 6.69 and 82.84 ± 8.7 mmHg, respectively. While the two groups were not significantly different in terms of HRR (P = 0.27, hs-CRP levels in the metabolic syndrome group was significantly higher than the other group (P = 0.02.

  11. Adaptive Changes in Basal Metabolic Rate in Humans in Different Eco-Geographical Areas.

    Science.gov (United States)

    Maximov, Arkady L; Belkin, Victor Sh; Kalichman, Leonid; Kobyliansky, Eugene D

    2015-12-01

    Our aim was to establish whether the human basal metabolic rate (BMR) shifts towards the reduction of vital functions as an adaptation response to extreme environmental conditions. Data was collected in arid and Extreme North zones. The arid zone samples included Bedouins living in the Sinai Peninsula in Egypt, Turkmen students, the Pedagogical University of Chardzhou, Turkmenistan born Russians and Russian soldiers. Soldiers were divided into 3 groups according to the length of their tour of duty in the area: 1st group: up to six months, 2nd group: up to 2 years and the 3rd group: 3-5 years. The Extreme North samples comprised Chukchi natives, 1st generation Russian immigrants born in the area and 3 groups of soldiers comparable to the soldiers from Turkmenistan. BMR values of the new recruits had the highest values of total and relative BMR (1769 ± 16 and 28.3 ± 0.6, correspondingly). The total and relative BMR tended to decrease within a longer adaptation period. The BMR values of officers who served >3 years in Turkmenistan were very similar to the Turkmenistan born Russians (1730 ± 14 vs. 1726 ± 18 and 26.5 ± 0.6 vs. 27.3 ± 0.7, correspondingly). Similarly, in Chukotka, the highest relative BMR was found in the new recruits, serving up to 6 months (28.1 ± 0.7) and was significantly (p BMR was virtually similar in Russian officers serving > 3 years, compared to the middle-aged Chukchi or Chukotka-born Russians (25.8 ± 0.5 vs. 25.6 ± 0.5 and 25.5 ± 0.6, correspondingly). The BMR parameters demonstrated a stronger association with body weight than with age. In extreme environmental conditions, migrant populations showed a decrease in BMR, thus reducing its vital functions. The BMR reduction effect with the adequate adaptive transformation is likely to be the key strategy for developing programs to facilitate human and animal adaptation to extreme factors. This process is aimed at preserving the optimum energy balance and homeostasis while minimizing

  12. 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

    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...... not used for aerobic metabolism. Although some of the excess glucose uptake can be explained by lactate production, this phenomenon can still not account for the excess glucose uptake. Thus, more complex metabolic patterns in the brain might be reflected in the excess glucose uptake during activation......, and especially temporal relationships must be taken into account. What triggers the flow increase during functional brain activation is not entirely elucidated. The demand for excess glucose uptake may be important and a possible oxygen deficit in tissue distant from the capillaries is probably of minor...

  13. Interest rate risk measurement in Brazilian sovereign markets

    Directory of Open Access Journals (Sweden)

    Caio Ibsen Rodrigues de Almeida

    2004-06-01

    Full Text Available Fixed income emerging markets are an interesting investment alternative. Measuring market risks is mandatory in order to avoid une