Science.gov

Sample records for 24-h energy balance

  1. Acute effect of ephedrine on 24-h energy balance

    NASA Technical Reports Server (NTRS)

    Shannon, J. R.; Gottesdiener, K.; Jordan, J.; Chen, K.; Flattery, S.; Larson, P. J.; Candelore, M. R.; Gertz, B.; Robertson, D.; Sun, M.

    1999-01-01

    Ephedrine is used to help achieve weight control. Data on its true efficacy and mechanisms in altering energy balance in human subjects are limited. We aimed to determine the acute effect of ephedrine on 24-h energy expenditure, mechanical work and urinary catecholamines in a double-blind, randomized, placebo-controlled, two-period crossover study. Ten healthy volunteers were given ephedrine (50 mg) or placebo thrice daily during each of two 24-h periods (ephedrine and placebo) in a whole-room indirect calorimeter, which accurately measures minute-by-minute energy expenditure and mechanical work. Measurements were taken of 24-h energy expenditure, mechanical work, urinary catecholamines and binding of (+/-)ephedrine in vitro to human beta1-, beta2- and beta3-adrenoreceptors. Twenty-four-hour energy expenditure was 3.6% greater (8965+/-1301 versus 8648+/-1347 kJ, P<0.05) with ephedrine than with placebo, but mechanical work was not different between the ephedrine and placebo periods. Noradrenaline excretion was lower with ephedrine (0.032+/-0.011 microg/mg creatinine) compared with placebo (0.044+/-0.012 microg/mg creatinine) (P<0.05). (+/-)Ephedrine is a relatively weak partial agonist of human beta1- and beta2-adrenoreceptors, and had no detectable activity at human beta3-adrenoreceptors. Ephedrine (50 mg thrice daily) modestly increases energy expenditure in normal human subjects. A lack of binding of ephedrine to beta3-adrenoreceptors and the observed decrease in urinary noradrenaline during ephedrine treatment suggest that the thermogenic effect of ephedrine results from direct beta1-/beta2-adrenoreceptor agonism. An indirect beta3-adrenergic effect through the release of noradrenaline seems unlikely as urinary noradrenaline decreased significantly with ephedrine.

  2. Perturbed energy balance and hydration status in ultra-endurance runners during a 24 h ultra-marathon.

    PubMed

    Costa, Ricardo J S; Gill, Samantha K; Hankey, Joanne; Wright, Alice; Marczak, Slawomir

    2014-08-14

    The present study aimed to assess the adequacy of energy, macronutrients and water intakes of ultra-endurance runners (UER) competing in a 24 h ultra-marathon (distance range: 122-208 km). The ad libitum food and fluid intakes of the UER (n 25) were recorded throughout the competition and analysed using dietary analysis software. Body mass (BM), urinary ketone presence, plasma osmolality (POsmol) and volume change were determined at pre- and post-competition time points. Data were analysed using appropriate t tests, with significance set at P <0·05. The total energy intake and expenditure of the UER were 20 (sd 12) and 55 (sd 11) MJ, respectively (control (CON) (n 17): 12 (sd 1) and 14 (sd 5) MJ, respectively). The protein, carbohydrate and fat intakes of the UER were 1·1 (sd 0·4), 11·3 (sd 7·0) and 1·5 (sd 0·7) g/kg BM, respectively. The rate of carbohydrate intake during the competition was 37 (sd 24) g/h. The total water intake of the UER was 9·1 (sd 4·0) litres (CON: 2·1 (sd 1·0) litres), while the rate of water intake was 378 (sd 164) ml/h. Significant BM loss occurred at pre- to post-competition time points (P =0·001) in the UER (1·6 (sd 2·0) %). No significant changes in POsmol values were observed at pre- (285 (sd 11) mOsmol/kg) to post-competition (287 (sd 10) mOsmol/kg) time points in the UER and were lower than those recorded in the CON group (P <0·05). However, plasma volume (PV) increased at post-competition time points in the UER (10·2 (sd 9·7) %; P <0·001). Urinary ketones were evident in the post-competition samples of 90 % of the UER. Energy deficit was observed in all the UER, with only one UER achieving the benchmark recommendations for carbohydrate intake during endurance exercise. Despite the relatively low water intake rates recorded in the UER, hypohydration does not appear to be an issue, considering increases in PV values observed in the majority (80 %) of the UER. Population-specific dietary recommendations may be

  3. Transient energy deficit induced by exercise increases 24-h fat oxidation in young trained men.

    PubMed

    Iwayama, Kaito; Kawabuchi, Ryosuke; Park, Insung; Kurihara, Reiko; Kobayashi, Masashi; Hibi, Masanobu; Oishi, Sachiko; Yasunaga, Koichi; Ogata, Hitomi; Nabekura, Yoshiharu; Tokuyama, Kumpei

    2015-01-01

    Whole body fat oxidation increases during exercise. However, 24-h fat oxidation on a day with exercise often remains similar to that of sedentary day, when energy intake is increased to achieve an energy-balanced condition. The present study aimed to examine a possibility that time of the day when exercise is performed makes differences in 24-h fat oxidation. As a potential mechanism of exercise affecting 24-h fat oxidation, its relation to exercise-induced transient energy deficit was examined. Nine young male endurance athletes underwent three trials of indirect calorimetry using a metabolic chamber, in which they performed a session of 100 min of exercise before breakfast (AM), after lunch (PM), or two sessions of 50 min of exercise before breakfast and after lunch (AM/PM) at 65% of maximal oxygen uptake. Experimental meals were designed to achieve individual energy balance. Twenty-four-hour energy expenditure was similar among the trials, but 24-h fat oxidation was 1,142 ± 97, 809 ± 88, and 608 ± 46 kcal/24 h in descending order of its magnitude for AM, AM/PM, and PM, respectively (P < 0.05). Twenty-four-hour carbohydrate oxidation was 2,558 ± 110, 2,374 ± 114, and 2,062 ± 96 kcal/24 h for PM, AM/PM, and AM, respectively. In spite of energy-balanced condition over 24 h, exercise induced a transient energy deficit, the magnitude of which was negatively correlated with 24-h fat oxidation (r = -0.72, P < 0.01). Similarly, transient carbohydrate deficit after exercise was negatively correlated with 24-h fat oxidation (r = -0.40, P < 0.05). The time of the day when exercise is performed affects 24-h fat oxidation, and the transient energy/carbohydrate deficit after exercise is implied as a factor affecting 24-h fat oxidation. PMID:25554797

  4. A Mobile Phone Based Method to Assess Energy and Food Intake in Young Children: A Validation Study against the Doubly Labelled Water Method and 24 h Dietary Recalls.

    PubMed

    Delisle Nyström, Christine; Forsum, Elisabet; Henriksson, Hanna; Trolle-Lagerros, Ylva; Larsson, Christel; Maddison, Ralph; Timpka, Toomas; Löf, Marie

    2016-01-01

    Mobile phones are becoming important instruments for assessing diet and energy intake. We developed the Tool for Energy Balance in Children (TECH), which uses a mobile phone to assess energy and food intake in pre-school children. The aims of this study were: (a) to compare energy intake (EI) using TECH with total energy expenditure (TEE) measured via doubly labelled water (DLW); and (b) to compare intakes of fruits, vegetables, fruit juice, sweetened beverages, candy, ice cream, and bakery products using TECH with intakes acquired by 24 h dietary recalls. Participants were 39 healthy, Swedish children (5.5 ± 0.5 years) within the ongoing Mobile-based Intervention Intended to Stop Obesity in Preschoolers (MINISTOP) obesity prevention trial. Energy and food intakes were assessed during four days using TECH and 24 h telephone dietary recalls. Mean EI (TECH) was not statistically different from TEE (DLW) (5820 ± 820 kJ/24 h and 6040 ± 680 kJ/24 h, respectively). No significant differences in the average food intakes using TECH and 24 h dietary recalls were found. All food intakes were correlated between TECH and the 24 h dietary recalls (ρ = 0.665-0.896, p < 0.001). In conclusion, TECH accurately estimated the average intakes of energy and selected foods and thus has the potential to be a useful tool for dietary studies in pre-school children, for example obesity prevention trials. PMID:26784226

  5. A Mobile Phone Based Method to Assess Energy and Food Intake in Young Children: A Validation Study against the Doubly Labelled Water Method and 24 h Dietary Recalls

    PubMed Central

    Delisle Nyström, Christine; Forsum, Elisabet; Henriksson, Hanna; Trolle-Lagerros, Ylva; Larsson, Christel; Maddison, Ralph; Timpka, Toomas; Löf, Marie

    2016-01-01

    Mobile phones are becoming important instruments for assessing diet and energy intake. We developed the Tool for Energy Balance in Children (TECH), which uses a mobile phone to assess energy and food intake in pre-school children. The aims of this study were: (a) to compare energy intake (EI) using TECH with total energy expenditure (TEE) measured via doubly labelled water (DLW); and (b) to compare intakes of fruits, vegetables, fruit juice, sweetened beverages, candy, ice cream, and bakery products using TECH with intakes acquired by 24 h dietary recalls. Participants were 39 healthy, Swedish children (5.5 ± 0.5 years) within the ongoing Mobile-based Intervention Intended to Stop Obesity in Preschoolers (MINISTOP) obesity prevention trial. Energy and food intakes were assessed during four days using TECH and 24 h telephone dietary recalls. Mean EI (TECH) was not statistically different from TEE (DLW) (5820 ± 820 kJ/24 h and 6040 ± 680kJ/24 h, respectively). No significant differences in the average food intakes using TECH and 24 h dietary recalls were found. All food intakes were correlated between TECH and the 24 h dietary recalls (ρ = 0.665–0.896, p < 0.001). In conclusion, TECH accurately estimated the average intakes of energy and selected foods and thus has the potential to be a useful tool for dietary studies in pre-school children, for example obesity prevention trials. PMID:26784226

  6. The 24-h Energy Intake of Obese Adolescents Is Spontaneously Reduced after Intensive Exercise: A Randomized Controlled Trial in Calorimetric Chambers

    PubMed Central

    Thivel, David; Isacco, Laurie; Montaurier, Christophe; Boirie, Yves

    2012-01-01

    Background Physical exercise can modify subsequent energy intake and appetite and may thus be of particular interest in terms of obesity treatment. However, it is still unclear whether an intensive bout of exercise can affect the energy consumption of obese children and adolescents. Objective To compare the impact of high vs. moderate intensity exercises on subsequent 24-h energy intake, macronutrient preferences, appetite sensations, energy expenditure and balance in obese adolescent. Design This randomized cross-over trial involves 15 obese adolescent boys who were asked to randomly complete three 24-h sessions in a metabolic chamber, each separated by at least 7 days: (1) sedentary (SED); (2) Low-Intensity Exercise (LIE) (40% maximal oxygen uptake, VO2max); (3) High-Intensity Exercise (HIE) (75%VO2max). Results Despite unchanged appetite sensations, 24-h total energy intake following HIE was 6–11% lower compared to LIE and SED (p<0.05), whereas no differences appeared between SED and LIE. Energy intake at lunch was 9.4% and 8.4% lower after HIE compared to SED and LIE, respectively (p<0.05). At dinner time, it was 20.5% and 19.7% lower after HIE compared to SED and LIE, respectively (p<0.01). 24-h energy expenditure was not significantly altered. Thus, the 24-h energy balance was significantly reduced during HIE compared to SED and LIE (p<0.01), whereas those of SED and LIE did not differ. Conclusions In obese adolescent boys, HIE has a beneficial impact on 24-h energy balance, mainly due to the spontaneous decrease in energy intake during lunch and dinner following the exercise bout. Prescribing high-intensity exercises to promote weight loss may therefore provide effective results without affecting appetite sensations and, as a result, food frustrations. Trial Registration ClinicalTrial.gov NCT01036360 PMID:22272251

  7. High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment.

    PubMed

    Skelly, Lauren E; Andrews, Patricia C; Gillen, Jenna B; Martin, Brian J; Percival, Michael E; Gibala, Martin J

    2014-07-01

    Subjects performed high-intensity interval training (HIIT) and continuous moderate-intensity training (END) to evaluate 24-h oxygen consumption. Oxygen consumption during HIIT was lower versus END; however, total oxygen consumption over 24 h was similar. These data demonstrate that HIIT and END induce similar 24-h energy expenditure, which may explain the comparable changes in body composition reported despite lower total training volume and time commitment. PMID:24773393

  8. A human calorimeter for the direct and indirect measurement of 24 h energy expenditure.

    PubMed

    Dauncey, M J; Murgatroyd, P R; Cole, T J

    1978-05-01

    1. A calorimeter for the continuous measurement of heat production and heat loss in the human subject, for at least 24 h, is described. The calorimeter operated on the heat-sink principle for direct calorimetry and an open-circuit system for indirect calorimetry. 2. Sensible heat loss was measured using a water-cooled heat exchanger, and the temperature of water entering the heat exchanger was controlled to maintain a mean temperature gradient of zero across the chamber walls. 3. Evaporative heat loss was determined from ingoing and outgoing wet-and-dry bulb temperatures and air flow-rates. 4. Problems associated with the calculation of evapoative heat loss and the estimation of the volume of incoming air in open-circuit systems are considered. 5. The calibration, limits of accuracy, sources of error and experiments with subjects are discussed. PMID:638125

  9. Effects of dietary fatty acid composition on 24-h energy expenditure and chronic disease risk factors in men123

    PubMed Central

    Cooper, Jamie A; Watras, Abigail C; Adams, Alexandra K; Schoeller, Dale A

    2009-01-01

    Background: A high-fat (HF) diet and sedentary lifestyle are implicated in the development of obesity. Controlled feeding studies and measures of short-term resting energy expenditure (REE) have suggested that the type of dietary fat may alter energy expenditure (EE). Objective: The objective was to examine the effects of an HF diet rich in either monounsaturated or saturated fatty acids (FAs) and of exercise on EE and chronic disease risk factors. Design: Eight healthy men [age: 18–45 y; body mass index (in kg/m2): 22 ± 3] were randomly assigned in a 2 × 2 crossover design to 1 of 4 treatments: HF diet (50% of energy) with a high amount of saturated fat (22% of energy) plus exercise (SE) or a sedentary (SS) condition or a diet high in monounsaturated fat (30% of energy) plus exercise (UE) or a sedentary (US) condition. The subjects spent 5 d in a metabolic chamber and cycled at 45% of maximal oxygen uptake for 2 h each day during the exercise visits. Respiratory gases and urinary nitrogen were measured to determine 24-h EE. Resting metabolic rate was measured on days 2, 4, and 6. Results: Average 24-h EE was not different with respect to dietary FA composition (3202 ± 146, 3208 ± 151, 2240 ± 82, and 2270 ± 104 for SE, UE, SS, and US, respectively). Total and LDL cholesterol and blood pressure were significantly greater after the SE and SS treatments than after the UE and US treatments. Conclusion: Resting metabolic rate and 24-h EE were not significantly different after short-term exposure to an HF diet rich in monounsaturated FAs or after exposure to a diet rich in saturated FAs in healthy, nonobese men. PMID:19321562

  10. Overestimation of infant and toddler energy intake by 24-h recall compared with weighed food records

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-four-hour dietary recalls have been used in large surveys of infant and toddler energy intake, but the accuracy of the method for young children is not well documented. We aimed to determine the accuracy of infant and toddler energy intakes by a single, telephone-administered, multiple-pass 2...

  11. Association of food form with self-reported 24-h energy intake and meal patterns in US adults: NHANES 2003–2008123

    PubMed Central

    Kant, Ashima K; Graubard, Barry I; Mattes, Richard D

    2012-01-01

    Background: Laboratory studies suggest that food form (beverages compared with solid foods) evokes behavioral and physiologic responses that modify short-term appetite and food intake. Beverage energy may be less satiating and poorly compensated, which leads to higher energy intake. Objective: We examined associations between 24-h energy consumed in beverages and a variety of meal and dietary attributes to quantify the contribution of beverage consumption to the energy content of diets in free-living individuals consuming their self-selected diets. Design: We used dietary recall data for adults (n = 13,704) in NHANES 2003–2008 to examine the multiple covariate-adjusted associations between 24-h energy from beverages and nonbeverages and associations between beverage intake, eating behaviors, and the energy density of beverage and nonbeverage foods. Results: In the highest tertile of 24-h beverage energy intake, beverages provided >30% of energy. Total 24-h energy and nonbeverage energy consumption and energy density (kcal/g) of both beverage and nonbeverage foods increased with increasing energy from beverages (P < 0.0001). With increasing 24-h beverage energy consumption, the reported frequency of all, snack, and beverage-only ingestive episodes and length of the ingestive period increased, whereas the percentage of energy from main meals decreased (P < 0.0001). Conclusions: Higher 24-h beverage energy intake was related to higher energy intake from nonbeverage foods, quality of food selections, and distribution of 24-h energy into main meal and snack episodes. Moderation of beverage-only ingestive episodes and curtailing the length of the ingestion period may hold potential to lower uncompensated beverage energy consumption in the US population. PMID:23097271

  12. Twelve weeks of moderate aerobic exercise without dietary intervention or weight loss does not affect 24-h energy expenditure in lean and obese adolescents.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exercise might have a persistent effect on energy expenditure and fat oxidation, resulting in increased fat loss. However, even without weight loss, exercise results in positive metabolic effects. The effect of an aerobic exercise program on 24-h total energy expenditure (TEE), and its components-ba...

  13. Energy Balance and Obesity

    PubMed Central

    Hill, James O.; Wyatt, Holly R.; Peters, John C.

    2012-01-01

    This paper describes the interplay among energy intake, energy expenditure and body energy stores and illustrates how an understanding of energy balance can help develop strategies to reduce obesity. First, reducing obesity will require modifying both energy intake and energy expenditure and not simply focusing on either alone. Food restriction alone will not be effective in reducing obesity if human physiology is biased toward achieving energy balance at a high energy flux (i.e. at a high level of energy intake and expenditure). In previous environments a high energy flux was achieved with a high level of physical activity but in today's sedentary environment it is increasingly achieved through weight gain. Matching energy intake to a high level of energy expenditure will likely be more a more feasible strategy for most people to maintain a healthy weight than restricting food intake to meet a low level of energy expenditure. Second, from an energy balance point of view we are likely to be more successful in preventing excessive weight gain than in treating obesity. This is because the energy balance system shows much stronger opposition to weight loss than to weight gain. While large behavior changes are needed to produce and maintain reductions in body weight, small behavior changes may be sufficient to prevent excessive weight gain. In conclusion, the concept of energy balance combined with an understanding of how the body achieves balance may be a useful framework in helping develop strategies to reduce obesity rates. PMID:22753534

  14. Regulation of Energy Balance.

    ERIC Educational Resources Information Center

    Bray, George A.

    1985-01-01

    Explains relationships between energy intake and expenditure focusing on the cellular, chemical and neural mechanisms involved in regulation of energy balance. Information is referenced specifically to conditions of obesity. (Physicians may earn continuing education credit by completing an appended test). (ML)

  15. Experimental sleep curtailment causes wake-dependent increases in 24-h energy expenditure as measured by whole-room indirect calorimetry1234

    PubMed Central

    Shechter, Ari; Rising, Russell; Albu, Jeanine B

    2013-01-01

    Background: Epidemiologic evidence has shown a link between short sleep and obesity. Clinical studies suggest a role of increased energy intake in this relation, whereas the contributions of energy expenditure (EE) and substrate utilization are less clearly defined. Objective: Our aim was to investigate the effects of sleep curtailment on 24-h EE and respiratory quotient (RQ) by using whole-room indirect calorimetry under fixed-meal conditions. Design: Ten females aged 22–43 y with a BMI (in kg/m2) of 23.4–27.5 completed a randomized, crossover study. Participants were studied under short- (4 h/night) and habitual- (8 h/night) sleep conditions for 3 d, with a 4-wk washout period between visits. Standardized weight-maintenance meals were served at 0800, 1200, and 1900 with a snack at 1600. Measures included EE and RQ during the sleep episode on day 2 and continuously over 23 h on day 3. Results: Short compared with habitual sleep resulted in significantly higher (±SEM) 24-h EE (1914.0 ± 62.4 compared with 1822.1 ± 43.8 kcal; P = 0.012). EE during the scheduled sleep episode (0100–0500 and 2300–0700 in short- and habitual-sleep conditions, respectively) and across the waking episode (0800–2300) were unaffected by sleep restriction. RQ was unaffected by sleep restriction. Conclusions: Short compared with habitual sleep is associated with an increased 24-h EE of ∼92 kcal (∼5%)—lower than the increased energy intake observed in prior sleep-curtailment studies. This finding supports the hypothesis that short sleep may predispose to weight gain as a result of an increase in energy intake that is beyond the modest energy costs associated with prolonged nocturnal wakefulness. This trial was registered at clinicaltrials.gov as NCT01751581. PMID:24088722

  16. Energy balance in peridynamics.

    SciTech Connect

    Lehoucq, Richard B.; Silling, Stewart Andrew

    2010-09-01

    The peridynamic model of solid mechanics treats internal forces within a continuum through interactions across finite distances. These forces are determined through a constitutive model that, in the case of an elastic material, permits the strain energy density at a point to depend on the collective deformation of all the material within some finite distance of it. The forces between points are evaluated from the Frechet derivative of this strain energy density with respect to the deformation map. The resulting equation of motion is an integro-differential equation written in terms of these interparticle forces, rather than the traditional stress tensor field. Recent work on peridynamics has elucidated the energy balance in the presence of these long-range forces. We have derived the appropriate analogue of stress power, called absorbed power, that leads to a satisfactory definition of internal energy. This internal energy is additive, allowing us to meaningfully define an internal energy density field in the body. An expression for the local first law of thermodynamics within peridynamics combines this mechanical component, the absorbed power, with heat transport. The global statement of the energy balance over a subregion can be expressed in a form in which the mechanical and thermal terms contain only interactions between the interior of the subregion and the exterior, in a form anticipated by Noll in 1955. The local form of this first law within peridynamics, coupled with the second law as expressed in the Clausius-Duhem inequality, is amenable to the Coleman-Noll procedure for deriving restrictions on the constitutive model for thermomechanical response. Using an idea suggested by Fried in the context of systems of discrete particles, this procedure leads to a dissipation inequality for peridynamics that has a surprising form. It also leads to a thermodynamically consistent way to treat damage within the theory, shedding light on how damage, including the

  17. Energy balance climate models

    NASA Technical Reports Server (NTRS)

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1981-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved, and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  18. Balancing the Energy Pendulum.

    ERIC Educational Resources Information Center

    MacKinnon, Sharon

    1987-01-01

    The city of Kitchener, Ontario, has installed a heat recovery loop in one indoor pool, all indoor swimming pools use pool covers, and two have solar heating. Energy is saved in two ice arenas by low-emissivity ceilings, and in the largest arena by a heat recovery system. (MLF)

  19. Meridional energy balance of Jupiter

    NASA Technical Reports Server (NTRS)

    Pirraglia, J. A.

    1984-01-01

    The meridional energy balance of Jupiter is calculated from high spatial resolution observations by the Voyager 1 infrared spectrometer and radiometer. On a hemispheric scale Jupiter radiates thermal energy to space approximately uniform with latitude while solar energy absorption varies approximately as the solar angle. This implies internal adjustment to the solar energy with a larger contribution poleward of + or - 45 deg than in the equatorial zone. The internal flux is modulated by the major visible features of the zone and belt system but, unlike the hemispheric scale where increased internal flux is correlated with decreased solar absorption, on smaller scales the inverse occurs. The energy balance is very likely to be controlled by dynamics, but the relative influence of the upper atmosphere and the interior is not yet clear.

  20. Energy balance in coronal funnels

    NASA Technical Reports Server (NTRS)

    Rabin, Douglas

    1991-01-01

    The energy balance in magnetic flux tubes is examined semianalytically for the case in which thermal conduction balances radiation or in which enthalpy transport occurs. Different values are considered for areal constriction, shape, length, and maximum temperature. The overall energy budget of the solar corona is not significantly affected by magnetic constriction. A bowl-shaped funnel with a constriction factor of 4 describes the empirical differential-emission measure for log-T values between approximately 5.3 and 6.0. Loop-scaling relationships are derived for the full range of models to illustrate the dependence of the constant of proportionality on the properties of the magnetic constriction. Constriction can reduce the total energy requirement of the funnel by a factor of 5 and not affect the differential emission in flow-dominated models.

  1. 24-h Efficacy of Glaucoma Treatment Options.

    PubMed

    Konstas, Anastasios G P; Quaranta, Luciano; Bozkurt, Banu; Katsanos, Andreas; Garcia-Feijoo, Julian; Rossetti, Luca; Shaarawy, Tarek; Pfeiffer, Norbert; Miglior, Stefano

    2016-04-01

    Current management of glaucoma entails the medical, laser, or surgical reduction of intraocular pressure (IOP) to a predetermined level of target IOP, which is commensurate with either stability or delayed progression of visual loss. In the published literature, the hypothesis is often made that IOP control implies a single IOP measurement over time. Although the follow-up of glaucoma patients with single IOP measurements is quick and convenient, such measurements often do not adequately reflect the untreated IOP characteristics, or indeed the quality of treated IOP control during the 24-h cycle. Since glaucoma is a 24-h disease and the damaging effect of elevated IOP is continuous, it is logical that we should aim to understand the efficacy of all treatment options throughout the 24-h period. This article first reviews the concept and value of diurnal and 24-h IOP monitoring. It then critically evaluates selected available evidence on the 24-h efficacy of medical, laser and surgical therapy options. During the past decade several controlled trials have significantly enhanced our understanding on the 24-h efficacy of all glaucoma therapy options. Nevertheless, more long-term evidence is needed to better evaluate the 24-h efficacy of glaucoma therapy and the precise impact of IOP characteristics on glaucomatous progression and visual prognosis. PMID:26909513

  2. Energy-balance climate models

    NASA Technical Reports Server (NTRS)

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1980-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  3. Energy balance of wheat conversion to ethanol

    SciTech Connect

    Stumborg, M.A.; Zentner, R.P.; Coxworth, E.

    1996-12-31

    The Western Canadian ethanol industry uses wheat as the preferred feed stock. The net energy balance of an ethanol system based on this starchy feed stock is of interest if Canada utilizes ethanol fuels from wheat as one of its measures to meet international commitments for greenhouse gas reduction and energy conservation under the Green Plan. The wheat to ethanol production systems for the Brown and Thin Black soil zones of the Canadian Prairies were analyzed from soil to processing completion to determine the net energy balance. The data clearly demonstrates the positive net energy balance, with the energy balance ranging from 1.32 to 1.63:1 for the Brown soil zone, and from 1.19 to 1.47:1 for the Thin Black soil zone. The final energy balance depends upon the agronomic practices and wheat variety assumed for the production system.

  4. Comprehensive Energy Balance Measurements in Mice.

    PubMed

    Moir, Lee; Bentley, Liz; Cox, Roger D

    2016-01-01

    In mice with altered body composition, establishing whether it is food intake or energy expenditure, or both, that is the major determinant resulting in changed energy balance is important. In order to ascertain where the imbalance is, the acquisition of reproducible data is critical. Therefore, here we provide detailed descriptions of how to determine energy balance in mice. This encompasses protocols for establishing energy intake from home cage measurement of food intake, determining energy lost in feces using bomb calorimetry, and using equations to calculate parameters such as energy intake (EI), digested energy intake (DEI), and metabolisable energy intake (MEI) to determine overall energy balance. We also discuss considerations that should be taken into account when planning these experiments, including diet and sample sizes. © 2016 by John Wiley & Sons, Inc. PMID:27584551

  5. Surface Energy Balance System (SEBS) Handbook

    SciTech Connect

    Cook, DR

    2011-02-14

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system at the Southern Great Plains (SGP), North Slope of Alaska (NSA), Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  6. [Energy balance among female athletes].

    PubMed

    Arieli, Rakefet; Constantini, Naama

    2012-02-01

    Athletes need to consume sufficient energy to meet their training demands, maintain their health, and if young, to ensure their growth and development. Athletes are often preoccupied by their body weight and shape, and in some sports might be subjected to pressure to lose weight by coaches, peers or themselves. Eating disorders and poor eating habits are prevalent among female athletes, especially in sport disciplines where low body weight is required to improve performance or for "aesthetic" appearance or in weight category sports. Low energy intake has deleterious effects on many systems, including the cardiovascular system, several hormonal pathways, musculoskeletal system, fluids and electrolytes, thermoregulation, growth and development. Various fitness components and overall performance are also negatively affected. All these, together with poor nutritional status that causes vitamin and mineral deficiencies, poor concentration and depression, put the athlete at an increased injury risk. Energy availability is now recognized as the primary factor initiating these health problems. Energy availability is defined as dietary energy intake minus exercise energy expenditure. If below 30 kcal/kg fat free mass per day, reproductive system functions, as well as other metabolic systems, might be suppressed. The case presented is of a young female Judoka, who complained of fatigue and weakness. Medical and nutritional assessment revealed that she suffered from low energy availability, which slowed her growth and development, and negatively affected her health and athletic performance. This case study emphasizes the importance of adequate energy availability in young female athletes in order to ensure their health. PMID:22741207

  7. Energy Landscape of Social Balance

    NASA Astrophysics Data System (ADS)

    Marvel, Seth A.; Strogatz, Steven H.; Kleinberg, Jon M.

    2009-11-01

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social “balance” allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying energy levels. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  8. Energy Balance of Rural Ecosystems In India

    NASA Astrophysics Data System (ADS)

    Chhabra, A.; Madhava Rao, V.; Hermon, R. R.; Garg, A.; Nag, T.; Bhaskara Rao, N.; Sharma, A.; Parihar, J. S.

    2014-11-01

    India is predominantly an agricultural and rural country. Across the country, the villages vary in geographical location, area, human and livestock population, availability of resources, agricultural practices, livelihood patterns etc. This study presents an estimation of net energy balance resulting from primary production vis-a-vis energy consumption through various components in a "Rural Ecosystem". Seven sites located in different agroclimatic regions of India were studied. An end use energy accounting "Rural Energy Balance Model" is developed for input-output analysis of various energy flows of production, consumption, import and export through various components of crop, trees outside forest plantations, livestock, rural households, industry or trade within the village system boundary. An integrated approach using field, ancillary, GIS and high resolution IRS-P6 Resourcesat-2 LISS IV data is adopted for generation of various model inputs. The primary and secondary field data collection of various energy uses at household and village level were carried out using structured schedules and questionnaires. High resolution multi-temporal Resourcesat-2 LISS IV data (2013-14) was used for generating landuse/landcover maps and estimation of above-ground Trees Outside Forests phytomass. The model inputs were converted to energy equivalents using country-specific energy conversion factors. A comprehensive geotagged database of sampled households and available resources at each study site was also developed in ArcGIS framework. Across the study sites, the estimated net energy balance ranged from -18.8 Terra Joules (TJ) in a high energy consuming Hodka village, Gujarat to 224.7 TJ in an agriculture, aquaculture and plantation intensive Kollaparru village, Andhra Pradesh. The results indicate that the net energy balance of a Rural Ecosystem is largely driven by primary production through crops and natural vegetation. This study provides a significant insight to policy

  9. The energy balance of the nighttime thermosphere

    NASA Technical Reports Server (NTRS)

    Glenar, D. A.

    1977-01-01

    The discrepancy between the input from the day hemisphere and the observed loss rates is discussed in terms of ion-neutral processes and gravity wave inputs. There has been considerable speculation as to the energy balance of the thermosphere and in particular about the fraction of the total energy input supplied by ultraviolet radiation. The problem is considerably simplified by considering the energy balance of the nighttime hemisphere alone. Sunrise and sunset vapor trail measurements provide data on the wind systems at the terminator boundary, and temperature measurements provide information on the vertical energy conduction. North-south winds from high latitude vapor trail measurements provide a measure of the energy input from auroral processes.

  10. Health in a 24-h society.

    PubMed

    Rajaratnam, S M; Arendt, J

    2001-09-22

    With increasing economic and social demands, we are rapidly evolving into a 24-h society. In any urban economy, about 20% of the population are required to work outside the regular 0800-1700 h working day and this figure is likely to increase. Although the increase in shiftwork has led to greater flexibility in work schedules, the ability to provide goods and services throughout the day and night, and possibly greater employment opportunities, the negative effects of shiftwork and chronic sleep loss on health and productivity are now being appreciated. For example, sleepiness surpasses alcohol and drugs as the greatest identifiable and preventable cause of accidents in all modes of transport. Industrial accidents associated with night work are common, perhaps the most famous being Chernobyl, Three Mile Island, and Bhopal. PMID:11583769

  11. An Energy Balance Concept for Habitability

    NASA Astrophysics Data System (ADS)

    Hoehler, Tori M.

    2007-12-01

    Habitability can be formulated as a balance between the biological demand for energy and the corresponding potential for meeting that demand by transduction of energy from the environment into biological process. The biological demand for energy is manifest in two requirements, analogous to the voltage and power requirements of an electrical device, which must both be met if life is to be supported. These requirements exhibit discrete (non-zero) minima whose magnitude is set by the biochemistry in question, and they are increased in quantifiable fashion by (i) deviations from biochemically optimal physical and chemical conditions and (ii) energy-expending solutions to problems of resource limitation. The possible rate of energy transduction is constrained by (i) the availability of usable free energy sources in the environment, (ii) limitations on transport of those sources into the cell, (iii) upper limits on the rate at which energy can be stored, transported, and subsequently liberated by biochemical mechanisms (e.g., enzyme saturation effects), and (iv) upper limits imposed by an inability to use ``power'' and ``voltage'' at levels that cause material breakdown. A system is habitable when the realized rate of energy transduction equals or exceeds the biological demand for energy. For systems in which water availability is considered a key aspect of habitability (e.g., Mars), the energy balance construct imposes additional, quantitative constraints that may help to prioritize targets in search-for-life missions. Because the biological need for energy is universal, the energy balance construct also helps to constrain habitability in systems (e.g., those envisioned to use solvents other than water) for which little constraint currently exists.

  12. Nexus of Poverty, Energy Balance and Health

    PubMed Central

    Mishra, C. P.

    2012-01-01

    Since the inception of planning process in India, health planning was an integral component of socio-economic planning. Recommendations of several committees, policy documents and Millennium development goals were instrumental in development of impressive health infrastructure. Several anti-poverty and employment generation programmes were instituted to remove poverty. Spectacular achievements took place in terms of maternal and child health indicators and expectancy of life at birth. However, communicable diseases and undernutrition remain cause of serious concern and non-communicable diseases are imposing unprecedented challenge to planners and policy makers. Estimates of poverty based on different criteria point that it has remained a sustained problem in the country and emphasizes on revisiting anti-poverty programmes, economic policies and social reforms. Poverty affects purchasing power and thereby, food consumption. Energy intake data has inherent limitations. It must be assessed in terms of energy expenditure. Energy balance has been least explored area of research. The studies conducted in three different representative population group of Eastern Uttar Pradesh revealed that 69.63% rural adolescent girls (10-19 years), 79.9% rural reproductive age group females and 62.3% rural geriatric subjects were in negative energy balance. Negative energy balance was significantly less in adolescent girls belonging to high SES (51.37%), having main occupation of family as business (55.3%), and highest per capita income group (57.1%) with respect to their corresponding sub-categories. In case of rural reproductive age groups, this was maximum (93.0%) in SC/ST category and least (65.7%) in upper caste group. In case of geriatric group, higher adjusted Odd's Ratio for negative energy balance for subjects not cared by family members (AOR 23.43, CI 3.93-139.56), not kept money (AOR 5.27, CI 1.58-17.56), belonging to lower and upper middle SES by Udai Pareekh Classification

  13. Neuropeptides controlling energy balance: orexins and neuromedins

    PubMed Central

    Nixon, Joshua P.; Kotz, Catherine M.; Novak, Colleen M.; Billington, Charles J.; Teske, Jennifer A.

    2016-01-01

    In this section we review the feeding and energy expenditure effects of orexin (also known as hypocretin) and neuromedin. Orexins are multifunctional neuropeptides that affect energy balance by participating in regulation of appetite, arousal, and spontaneous physical activity. Central orexin signaling for all functions originates in the lateral hypothalamus–perifornical area, and is likely functionally differentiated based on site of action and on interacting neural influences. The effect of orexin on feeding is likely related to arousal in some ways, but is nonetheless a separate neural process that depends on interactions with other feeding related neuropeptides. In a pattern distinct from other neuropeptides, orexin stimulates both feeding and energy expenditure. Orexin increases in energy expenditure are mainly by increasing spontaneous physical activity, and this energy expenditure effect is more potent than the effect on feeding. Global orexin manipulations, such as in transgenic models, produce energy balance changes consistent with a dominant energy expenditure effect of orexin. Neuromedins are gut-brain peptides that reduce appetite. There are gut sources of neuromedin, but likely the key appetite related neuromedin producing neurons are in hypothalamus and parallel other key anorectic neuropeptide expression in the arcuate to paraventricular hypothalamic projection. As with other hypothalamic feeding related peptides, hindbrain sites are likely also important sources and targets of neuromedin anorectic action. Neuromedin increases physical activity in addition to reducing appetite, thus producing a consistent negative energy balance effect. Together with the various other neuro-peptides, -transmitters, -modulators and –hormones, neuromedin and orexin act in the appetite network to produce changes in food intake and energy expenditure, which ultimately influences the regulation of body weight. PMID:22249811

  14. Evaluation of Two Energy Balance Closure Parametrizations

    NASA Astrophysics Data System (ADS)

    Eder, Fabian; De Roo, Frederik; Kohnert, Katrin; Desjardins, Raymond L.; Schmid, Hans Peter; Mauder, Matthias

    2014-05-01

    A general lack of energy balance closure indicates that tower-based eddy-covariance (EC) measurements underestimate turbulent heat fluxes, which calls for robust correction schemes. Two parametrization approaches that can be found in the literature were tested using data from the Canadian Twin Otter research aircraft and from tower-based measurements of the German Terrestrial Environmental Observatories (TERENO) programme. Our analysis shows that the approach of Huang et al. (Boundary-Layer Meteorol 127:273-292, 2008), based on large-eddy simulation, is not applicable to typical near-surface flux measurements because it was developed for heights above the surface layer and over homogeneous terrain. The biggest shortcoming of this parametrization is that the grid resolution of the model was too coarse so that the surface layer, where EC measurements are usually made, is not properly resolved. The empirical approach of Panin and Bernhofer (Izvestiya Atmos Oceanic Phys 44:701-716, 2008) considers landscape-level roughness heterogeneities that induce secondary circulations and at least gives a qualitative estimate of the energy balance closure. However, it does not consider any feature of landscape-scale heterogeneity other than surface roughness, such as surface temperature, surface moisture or topography. The failures of both approaches might indicate that the influence of mesoscale structures is not a sufficient explanation for the energy balance closure problem. However, our analysis of different wind-direction sectors shows that the upwind landscape-scale heterogeneity indeed influences the energy balance closure determined from tower flux data. We also analyzed the aircraft measurements with respect to the partitioning of the "missing energy" between sensible and latent heat fluxes and we could confirm the assumption of scalar similarity only for Bowen ratios 1.

  15. Surface Energy Balance System (SEBS) Handbook

    SciTech Connect

    Cook, D. R.

    2016-01-01

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed Eddy Correlation Flux Measurement System (ECOR) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, North Slope of Alaska (NSA) site, first ARM Mobile Facility (AMF1), second ARM Mobile Facility (AMF2), and third ARM Mobile Facility (AMF3) at Oliktok Point (OLI). A SEBS was also deployed with the Tropical Western Pacific (TWP) site, before it was decommissioned. Data from these sites, including the retired TWP, are available in the ARM Data Archive. The SEBS consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  16. Importance of energy balance in agriculture.

    NASA Astrophysics Data System (ADS)

    Meco, R.; Moreno, M. M.; Lacasta, C.; Tarquis, A. M.; Moreno, C.

    2012-04-01

    Since the beginning, man has tried to control nature and the environment, and the use of energy, mainly from non-renewable sources providing the necessary power for that. The consequences of this long fight against nature has reached a critical state of unprecedented worldwide environmental degradation, as evidenced by the increasing erosion of fertile lands, the deforestation processes, the pollution of water, air and land by agrochemicals, the loss of plant and animal species, the progressive deterioration of the ozone layer and signs of global warming. This is exacerbated by the increasing population growth, implying a steady increase in consumption, and consequently, in the use of energy. Unfortunately, all these claims are resulting in serious economic and environmental problems worldwide. Because the economic and environmental future of the countries is interrelated, it becomes necessary to adopt sustainable development models based on the use of renewable and clean energies, the search for alternative resources and the use of productive systems more efficient from an energy standpoint, always with a reduction of greenhouse gas emissions. In relation to the agricultural sector, the question we ask is: how long can we keep the current energy-intensive agricultural techniques in developed countries? To analyze this aspect, energy balance is a very helpful tool because can lead to more efficient, sustainable and environment-friendly production systems for each agro-climatic region. This requires the identification of all the inputs and the outputs involved and their conversion to energy values by means of corresponding energy coefficients or equivalents (International Federation of Institutes for Advanced Studies). Energy inputs (EI) can be divided in direct (energy directly used in farms as fuel, machines, fertilizers, seeds, herbicides, human labor, etc.) and indirect (energy not consumed in the farm but in the elaboration, manufacturing or manipulation of

  17. Effects of Hypothalamic Neurodegeneration on Energy Balance

    PubMed Central

    2005-01-01

    Normal aging in humans and rodents is accompanied by a progressive increase in adiposity. To investigate the role of hypothalamic neuronal circuits in this process, we used a Cre-lox strategy to create mice with specific and progressive degeneration of hypothalamic neurons that express agouti-related protein (Agrp) or proopiomelanocortin (Pomc), neuropeptides that promote positive or negative energy balance, respectively, through their opposing effects on melanocortin receptor signaling. In previous studies, Pomc mutant mice became obese, but Agrp mutant mice were surprisingly normal, suggesting potential compensation by neuronal circuits or genetic redundancy. Here we find that Pomc-ablation mice develop obesity similar to that described for Pomc knockout mice, but also exhibit defects in compensatory hyperphagia similar to what occurs during normal aging. Agrp-ablation female mice exhibit reduced adiposity with normal compensatory hyperphagia, while animals ablated for both Pomc and Agrp neurons exhibit an additive interaction phenotype. These findings provide new insight into the roles of hypothalamic neurons in energy balance regulation, and provide a model for understanding defects in human energy balance associated with neurodegeneration and aging. PMID:16296893

  18. Comparison of INTAKE24 (an Online 24-h Dietary Recall Tool) with Interviewer-Led 24-h Recall in 11–24 Year-Old

    PubMed Central

    Bradley, Jennifer; Simpson, Emma; Poliakov, Ivan; Matthews, John N. S.; Olivier, Patrick; Adamson, Ashley J.; Foster, Emma

    2016-01-01

    Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11–24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method) with interviewer-led multiple pass 24-h recalls (the comparison method) in 180 people aged 11–24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars) were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults. PMID:27294952

  19. Comparison of INTAKE24 (an Online 24-h Dietary Recall Tool) with Interviewer-Led 24-h Recall in 11-24 Year-Old.

    PubMed

    Bradley, Jennifer; Simpson, Emma; Poliakov, Ivan; Matthews, John N S; Olivier, Patrick; Adamson, Ashley J; Foster, Emma

    2016-01-01

    Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11-24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method) with interviewer-led multiple pass 24-h recalls (the comparison method) in 180 people aged 11-24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars) were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults. PMID:27294952

  20. Energy balance comparison of sorghum and sunflower

    NASA Astrophysics Data System (ADS)

    Rachidi, F.; Kirkham, M. B.; Kanemasu, E. T.; Stone, L. R.

    1993-03-01

    An understanding of the energy exchange processes at the surface of the earth is necessary for studies of global climate change. If the climate becomes drier, as is predicted for northern mid-latitudes, it is important to know how major agricultural crops will play a role in the budget of heat and moisture. Thus, the energy balance components of sorghum [ Sorghum bicolor (L.) Moench.] and sunflower ( Helianthus annuus L.), two drought-resistant crops grown in the areas where summertime drying is forecasted, were compared. Soil water content and evapotranspiration ( ET) rates also were determined. Net radiation was measured with net radiometers. Soil heat flux was analyzed with heat flux plates and thermocouples. The Bowen ratio method was used to determine sensible and latent heat fluxes. Sunflower had a higher evapotranspiration rate and depleted more water from the soil than sorghum. Soil heat flux into the soil during the daytime was greater for sorghum than sunflower, which was probably the result of the more erect leaves of sorghum. Nocturnal net radiation loss from the sorghum crop was greater than that from the sunflower crop, perhaps because more heat was stored in the soil under the sorghum crop. But daytime net radiation values were similar for the two crops. The data indicated that models of climate change must differentiate nighttime net radiation of agricultural crops. Sensible heat flux was not always less (or greater) for sorghum compared to sunflower. Sunflower had greater daytime values for latent heat flux, reflecting its greater depletion of water from the soil. Evapotranspiration rates determined by the energy balance method agreed relatively well with those found by the water balance method. For example, on 8 July (43 days after planting), the ET rates found by the energy-balance and water-balance methods were 4.6 vs. 5.5 mm/day for sunflower, respectively; for sorghum, these values were 4.0 vs. 3.5 mm/day, respectively. If the climate does

  1. The Energy Balance Study: The Design and Baseline Results for a Longitudinal Study of Energy Balance

    ERIC Educational Resources Information Center

    Hand, Gregory A.; Shook, Robin P.; Paluch, Amanda E.; Baruth, Meghan; Crowley, E. Patrick; Jaggers, Jason R.; Prasad, Vivek K.; Hurley, Thomas G.; Hebert, James R.; O'Connor, Daniel P.; Archer, Edward; Burgess, Stephanie; Blair, Steven N.

    2013-01-01

    Purpose: The Energy Balance Study (EBS) was a comprehensive study designed to determine over a period of 12 months the associations of caloric intake and energy expenditure on changes in body weight and composition in a population of healthy men and women. Method: EBS recruited men and women aged 21 to 35 years with a body mass index between 20…

  2. Energy balance and non-turbulent fluxes

    NASA Astrophysics Data System (ADS)

    Moderow, Uta; Feigenwinter, Christian; Bernhofer, Christian

    2010-05-01

    Often, the sum of the turbulent fluxes of sensible heat and latent heat from eddy covariance (EC) measurements does not match the available energy (sum of net radiation, ground heat flux and storage changes). This is referred to as energy balance closure gap. The reported imbalances vary between 0% and 50% (Laubach 1996). In various publications, it has been shown that the uncertainty of the available energy itself does not explain the gap (Vogt et al. 1996; Moderow et al. 2009). Among other reasons, the underestimation is attributed to an underestimation of turbulent fluxes and undetected non-turbulent transport processes, i.e. advection (e.g. Foken et al. 2006). The imbalance is typically larger during nighttime than during daytime as the EC method fails to capture non-turbulent transports that can be significant during night (e.g. Aubinet 2008). Results for the budget of CO2 showed that including non-turbulent fluxes can change the budgets considerably. Hence, it is interesting to see how the budget of energy is changed. Here, the consequences of including advective fluxes of sensible heat and latent heat in the energy balance are explored with focus on nighttime conditions. Non-turbulent fluxes will be inspected critically regarding their plausibility. Following Bernhofer et al. (2003), a ratio similar to Bowen's ratio of the turbulent fluxes are defined for the non-turbulent fluxes and compared to each other. This might have implications for the partitioning of the available energy into sensible heat and latent heat. Data of the ADVEX-campaigns (Feigenwinter et al. 2008) of three different sites across Europe are used and selected periods are inspected. References Aubinet M (2008) Eddy covariance CO2-flux measurements in nocturnal conditions: An analysis of the problem. Ecol Appl 18: 1368-1378 Bernhofer C, Grünwald T, Schwiebus A, Vogt R (2003) Exploring the consequences of non-zero energy balance closure for total surface flux. In: Bernhofer C (ed

  3. Energy balance in the WTC collapse

    NASA Astrophysics Data System (ADS)

    Zhu, Kaiqi; Xu, Kang; Ansourian, Peter; Tahmasebinia, Faham; Alonso-Marroquin, Fernando

    2016-08-01

    The main aim of this report is to provide an analysis of Twin Towers of the New York City's World Trade Centre collapsed after attacked by two jet aircrafts. The approach mainly focused on the effect of temperature on mechanical properties of the building, by modelling heat energy in the south tower. Energy balance during the collapse between the energy inputs by aircraft petrol and the transient heat to the towers was conducted. Both the overall structure between 80 to 83 stories and individual elements was modelled. The main elements contributed to the heat transition includes external and internal columns. Heat applied in 2D and 3D models for single elements was through convection and conduction. Analysis of transient heat was done using Strand7.

  4. Energy Balance in Clusters of Galaxies

    NASA Astrophysics Data System (ADS)

    Motl, P. M.; Burns, J. M.

    2005-04-01

    We review different physical mechanisms that are likely to play a significant role in determining the detailed thermal state of gas in clusters of galaxies. Mergers are the dominant process impacting clusters and these collisions significantly perturb the cluster state. The continual loss of energy from the gas to radiation must also be accounted for and cooling gas can drive several positive feedback mechanisms. From simple energy arguments, AGN are likely to make a significant contribution to balance the energy lost from cluster cores. We also explore additional positive feedback mechanisms including supernovae feedback and thermal conduction. If AGN are the sole feedback mechanism, what are to be made of clusters that lack evidence for AGN activity yet have canonical cool cores? As cluster samples with high-resolution X-ray data grow larger, it is likely to be the properties of relaxed, cool-core clusters that will be the best guides to numerical simulations.

  5. Energy Expenditure and Caloric Balance After Burn

    PubMed Central

    Hart, David W.; Wolf, Steven E.; Herndon, David N.; Chinkes, David L.; Lal, Sophia O.; Obeng, Michael K.; Beauford, Robert B.; Mlcak RT, Ronald P.

    2002-01-01

    Objective Resting energy expenditure (REE) is commonly measured in critical illness to determine caloric “demands” and thus nutritive needs. Summary Background Data The purpose of this study was to 1) determine whether REE is associated with clinical outcomes and 2) determine whether an optimal caloric delivery rate based on REE exists to offset erosion of lean mass after burn. Methods From 1995 to 2001, REE was measured by indirect calorimetry in 250 survivors of 10 to 99%TBSA burns. Caloric intake and REE were correlated with muscle protein catabolism, length of stay, ventilator dependence, sepsis, and mortality. From 1998 to 2000, 42 patients (>60%TBSA burns) received continuous enteral nutrition at a spectrum of caloric balance between 1.0x REE kcal/d –1.8x REE kcal/d. Serial body composition was measured by dual energy x-ray absorptiometry. Lean mass, fat mass, morbidity, and mortality were determined. Results REE/predicted basal metabolic rate correlated directly with burn size, sepsis, ventilator dependence, and muscle protein catabolism (P < .05). Declining REE correlated with mortality (P < .05). 2) Erosion of lean body mass was not attenuated by increased caloric balance, however, fat mass increased with caloric supply (P < .05). Conclusion In surviving burned patients, caloric delivery beyond 1.2 × REE results in increased fat mass without changes in lean body mass. Declining energy expenditure appears to be a harbinger of mortality in severely burned patients. PMID:11753055

  6. Energy Balance Bowen Ratio Station (EBBR) Handbook

    SciTech Connect

    Cook, DR

    2011-02-23

    The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  7. Energy Balance Bowen Ratio (EBBR) Handbook

    SciTech Connect

    Cook, D. R.

    2016-01-01

    The Energy Balance Bowen Ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  8. Validity and relative validity of a novel digital approach for 24-h dietary recall in athletes

    PubMed Central

    2014-01-01

    Background We developed a digital dietary analysis tool for athletes (DATA) using a modified 24-h recall method and an integrated, customized nutrient database. The purpose of this study was to assess DATA’s validity and relative validity by measuring its agreement with registered dietitians’ (RDs) direct observations (OBSERVATION) and 24-h dietary recall interviews using the USDA 5-step multiple-pass method (INTERVIEW), respectively. Methods Fifty-six athletes (14–20 y) completed DATA and INTERVIEW in randomized counter-balanced order. OBSERVATION (n = 26) consisted of RDs recording participants’ food/drink intake in a 24-h period and were completed the day prior to DATA and INTERVIEW. Agreement among methods was estimated using a repeated measures t-test and Bland-Altman analysis. Results The paired differences (with 95% confidence intervals) between DATA and OBSERVATION were not significant for carbohydrate (10.1%, -1.2–22.7%) and protein (14.1%, -3.2–34.5%) but was significant for energy (14.4%, 1.2–29.3%). There were no differences between DATA and INTERVIEW for energy (-1.1%, -9.1–7.7%), carbohydrate (0.2%, -7.1–8.0%) or protein (-2.7%, -11.3–6.7%). Bland-Altman analysis indicated significant positive correlations between absolute values of the differences and the means for OBSERVATION vs. DATA (r = 0.40 and r = 0.47 for energy and carbohydrate, respectively) and INTERVIEW vs. DATA (r = 0.52, r = 0.29, and r = 0.61 for energy, carbohydrate, and protein, respectively). There were also wide 95% limits of agreement (LOA) for most method comparisons. The mean bias ratio (with 95% LOA) for OBSERVATION vs. DATA was 0.874 (0.551-1.385) for energy, 0.906 (0.522-1.575) for carbohydrate, and 0.895(0.395-2.031) for protein. The mean bias ratio (with 95% LOA) for INTERVIEW vs. DATA was 1.016 (0.538-1.919) for energy, 0.995 (0.563-1.757) for carbohydrate, and 1.031 (0.514-2.068) for protein. Conclusion DATA has good relative

  9. High-Intensity Sweeteners and Energy Balance

    PubMed Central

    Swithers, Susan E.; Martin, Ashley A.; Davidson, Terry L.

    2010-01-01

    Recent epidemiological evidence points to a link between a variety of negative health outcomes (e.g. metabolic syndrome, diabetes and cardiovascular disease) and the consumption of both calorically sweetened beverages and beverages sweetened with high-intensity, non-caloric sweeteners. Research on the possibility that non-nutritive sweeteners promote food intake, body weight gain, and metabolic disorders has been hindered by the lack of a physiologically-relevant model that describes the mechanistic basis for these outcomes. We have suggested that based on Pavlovian conditioning principles, consumption of non-nutritive sweeteners could result in sweet tastes no longer serving as consistent predictors of nutritive postingestive consequences. This dissociation between the sweet taste cues and the caloric consequences could lead to a decrease in the ability of sweet tastes to evoke physiological responses that serve to regulate energy balance. Using a rodent model, we have found that intake of foods or fluids containing non-nutritive sweeteners was accompanied by increased food intake, body weight gain, accumulation of body fat, and weaker caloric compensation, compared to consumption of foods and fluids containing glucose. Our research also provided evidence consistent with the hypothesis that these effects of consuming saccharin may be associated with a decrement in the ability of sweet taste to evoke thermic responses, and perhaps other physiological, cephalic phase, reflexes that are thought to help maintain energy balance. PMID:20060008

  10. High-intensity sweeteners and energy balance.

    PubMed

    Swithers, Susan E; Martin, Ashley A; Davidson, Terry L

    2010-04-26

    Recent epidemiological evidence points to a link between a variety of negative health outcomes (e.g. metabolic syndrome, diabetes and cardiovascular disease) and the consumption of both calorically sweetened beverages and beverages sweetened with high-intensity, non-caloric sweeteners. Research on the possibility that non-nutritive sweeteners promote food intake, body weight gain, and metabolic disorders has been hindered by the lack of a physiologically-relevant model that describes the mechanistic basis for these outcomes. We have suggested that based on Pavlovian conditioning principles, consumption of non-nutritive sweeteners could result in sweet tastes no longer serving as consistent predictors of nutritive postingestive consequences. This dissociation between the sweet taste cues and the caloric consequences could lead to a decrease in the ability of sweet tastes to evoke physiological responses that serve to regulate energy balance. Using a rodent model, we have found that intake of foods or fluids containing non-nutritive sweeteners was accompanied by increased food intake, body weight gain, accumulation of body fat, and weaker caloric compensation, compared to consumption of foods and fluids containing glucose. Our research also provided evidence consistent with the hypothesis that these effects of consuming saccharin may be associated with a decrement in the ability of sweet taste to evoke thermic responses, and perhaps other physiological, cephalic phase, reflexes that are thought to help maintain energy balance. PMID:20060008

  11. Exercise, energy balance and the shift worker.

    PubMed

    Atkinson, Greg; Fullick, Sarah; Grindey, Charlotte; Maclaren, Don

    2008-01-01

    Shift work is now common in society and is not restricted to heavy industry or emergency services, but is increasingly found amongst 'white collar' occupations and the growing number of service industries. Participation in shift work is associated with increased body mass index, prevalence of obesity and other health problems. We review the behavioural and biological disturbances that occur during shift work and discuss their impact on leisure-time physical activity and energy balance. Shift work generally decreases opportunities for physical activity and participation in sports. For those shift workers who are able to exercise, subjective and biological responses can be altered if the exercise is taken at unusual times of day and/or if the shift worker is sleep deprived. These altered responses may in turn impact on the longer-term adherence to an exercise programme. The favourable effects of exercise on body mass control and sleep quality in shift workers have not been confirmed. Similarly, recent reports of relationships between sleep duration and obesity have not been examined in a shift work context. There is no evidence that exercise can mediate certain circadian rhythm characteristics (e.g. amplitude or timing) for improved tolerance to shift work. Total energy intake and meal composition do not seem to be affected by participation in shift work. Meal frequency is generally reduced but snacking is increased on the night shift. Unavailability of preferred foods in the workplace, a lack of time, and a reduced desire to eat at night explain these findings. 'Normal' eating habits with the family are also disrupted. The metabolic responses to food are also altered by shift work-mediated disruptions to sleep and circadian rhythms. Whether any interactions on human metabolism exist between timing or content of food intake and physical activity during shift work is not known at present. There are very few randomized controlled studies on the efficacy of physical

  12. Exercise, Energy Balance and the Shift Worker

    PubMed Central

    Atkinson, Greg; Fullick, Sarah; Grindey, Charlotte; Maclaren, Don; Waterhouse, Jim

    2009-01-01

    Shift work is now common in society and is not restricted to heavy industry or emergency services, but is increasingly found amongst ‘white collar’ occupations and the growing number of service industries. Participation in shift work is associated with increased body mass index, prevalence of obesity and other health problems. We review the behavioural and biological disturbances that occur during shift work and discuss their impact on leisure-time physical activity and energy balance. Shift work generally decreases opportunities for physical activity and participation in sports. For those shift workers who are able to exercise, subjective and biological responses can be altered if the exercise is taken at unusual times of day and/or if the shift worker is sleep-deprived. These altered responses may in turn impact on the longer-term adherence to an exercise programme. The favourable effects of exercise on body mass control and sleep quality have not been confirmed in shift workers. Similarly, recent reports of relationships between sleep duration and obesity have not been examined in a shift work context. There is no evidence that exercise can mediate certain circadian rhythm characteristics (e.g. amplitude or timing) for improved tolerance to shift work. Total energy intake and meal composition do not seem to be affected by participation in shift work. Meal frequency is generally reduced but snacking is increased on the night shift. Unavailability of preferred foods in the workplace, a lack of time, and a reduced desire to eat at night explain these findings. ‘Normal’ eating habits with the family are also disrupted. The metabolic responses to food are also altered by shift work-mediated disruptions to sleep and circadian rhythms. Whether any interactions on human metabolism exist between timing or content of food intake and physical activity during shift work is not known at present. There are very few randomised controlled studies on the efficacy of

  13. Energy Balance Models and Planetary Dynamics

    NASA Technical Reports Server (NTRS)

    Domagal-Goldman, Shawn

    2012-01-01

    We know that planetary dynamics can have a significant affect on the climate of planets. Planetary dynamics dominate the glacial-interglacial periods on Earth, leaving a significant imprint on the geological record. They have also been demonstrated to have a driving influence on the climates of other planets in our solar system. We should therefore expect th.ere to be similar relationships on extrasolar planets. Here we describe a simple energy balance model that can predict the growth and thickness of glaciers, and their feedbacks on climate. We will also describe model changes that we have made to include planetary dynamics effects. This is the model we will use at the start of our collaboration to handle the influence of dynamics on climate.

  14. Fasting for 24 h improves nasal chemosensory performance and food palatability in a related manner.

    PubMed

    Cameron, Jameason D; Goldfield, Gary S; Doucet, Éric

    2012-06-01

    Changes in smell function can modify feeding behaviour but there is little evidence of how acute negative energy balance may impact olfaction and palatability. In a within-subjects repeated measures design, 15 subjects (nine male; six female) aged 28.6±4.5 years with initial body weight (BW) 74.7±4.9 kg and body mass index (BMI) 25.3±1.4 kg/m(2) were randomized and tested at baseline (FED) and Post Deprivation (FASTED) for nasal chemosensory performance (Sniffin' Sticks) and food palatability (visual analogue scale). Significant main effects for time indicated improvements in the FASTED session for odor threshold, odor discrimination, and total odor scores (TDI), and for increased palatability. There were significant positive correlations between initial BW and the change in odor threshold (r=.52) and TDI scores (r=.53). Positive correlations were also noted between delta identification score and delta palatability (r=.68). When the sample was split by sex, only for females were there significant correlations between delta palatability and: delta BW (r=.88); delta odor identification (r=.94); and delta TDI score (r=.85). Fasting for 24h improved smell function and this was related to increased palatability ratings and initial BW. Further studies should confirm the role of BW and sex in the context of olfaction, energy deprivation and palatability. PMID:22387713

  15. Does an Adolescent's Accuracy of Recall Improve with a Second 24-h Dietary Recall?

    PubMed

    Kerr, Deborah A; Wright, Janine L; Dhaliwal, Satvinder S; Boushey, Carol J

    2015-05-01

    The multiple-pass 24-h dietary recall is used in most national dietary surveys. Our purpose was to assess if adolescents' accuracy of recall improved when a 5-step multiple-pass 24-h recall was repeated. Participants (n = 24), were Chinese-American youths aged between 11 and 15 years and lived in a supervised environment as part of a metabolic feeding study. The 24-h recalls were conducted on two occasions during the first five days of the study. The four steps (quick list; forgotten foods; time and eating occasion; detailed description of the food/beverage) of the 24-h recall were assessed for matches by category. Differences were observed in the matching for the time and occasion step (p < 0.01), detailed description (p < 0.05) and portion size matching (p < 0.05). Omission rates were higher for the second recall (p < 0.05 quick list; p < 0.01 forgotten foods). The adolescents over-estimated energy intake on the first (11.3% ± 22.5%; p < 0.05) and second recall (10.1% ± 20.8%) compared with the known food and beverage items. These results suggest that the adolescents' accuracy to recall food items declined with a second 24-h recall when repeated over two non-consecutive days. PMID:25984743

  16. Does an Adolescent’s Accuracy of Recall Improve with a Second 24-h Dietary Recall?

    PubMed Central

    Kerr, Deborah A.; Wright, Janine L.; Dhaliwal, Satvinder S.; Boushey, Carol J.

    2015-01-01

    The multiple-pass 24-h dietary recall is used in most national dietary surveys. Our purpose was to assess if adolescents’ accuracy of recall improved when a 5-step multiple-pass 24-h recall was repeated. Participants (n = 24), were Chinese-American youths aged between 11 and 15 years and lived in a supervised environment as part of a metabolic feeding study. The 24-h recalls were conducted on two occasions during the first five days of the study. The four steps (quick list; forgotten foods; time and eating occasion; detailed description of the food/beverage) of the 24-h recall were assessed for matches by category. Differences were observed in the matching for the time and occasion step (p < 0.01), detailed description (p < 0.05) and portion size matching (p < 0.05). Omission rates were higher for the second recall (p < 0.05 quick list; p < 0.01 forgotten foods). The adolescents over-estimated energy intake on the first (11.3% ± 22.5%; p < 0.05) and second recall (10.1% ± 20.8%) compared with the known food and beverage items. These results suggest that the adolescents’ accuracy to recall food items declined with a second 24-h recall when repeated over two non-consecutive days. PMID:25984743

  17. Balancing Energy-Water-Agriculture Tradeoffs

    NASA Astrophysics Data System (ADS)

    Tidwell, V.; Hightower, M.

    2011-12-01

    In 2005 thermoelectric power production accounted for withdrawals of 201 billion gallons per day (BGD) representing 49% of total withdrawals, making it the largest user of water in the U.S. In terms of freshwater withdrawals thermoelectric power production is the second largest user at 140 BGD just slightly behind freshwater withdrawals for irrigation (USGS 2005). In contrast thermoelectric water consumption is projected at 3.7 BGD or about 3% of total U.S. consumption (NETL 2008). Thermoelectric water consumption is roughly equivalent to that of all other industrial demands and represents one of the fastest growing sectors since 1980. In fact thermoelectric consumption is projected to increase by 42 to 63% between 2005 and 2030 (NETL 2008). Agricultural water consumption has remained relatively constant at roughly 84 BGD or about 84% of total water consumption. While long-term regional electricity transmission planning has traditionally focused on cost, infrastructure utilization, and reliability, issues concerning the availability of water represent an emerging issue. Thermoelectric expansion must be considered in the context of competing demands from other water use sectors balanced with fresh and non-fresh water supplies subject to climate variability. Often such expansion targets water rights transfers from irrigated agriculture. To explore evolving tradeoffs an integrated energy-water-agriculture decision support system has been developed. The tool considers alternative expansion scenarios for the future power plant fleet and the related demand for water. The availability of fresh and non-fresh water supplies, subject to local institutional controls is then explored. This paper addresses integrated energy-water-agriculture planning in the western U.S. and Canada involving an open and participatory process comprising decision-makers, regulators, utility and water managers.

  18. Enhanced vagal baroreflex response during 24 h after acute exercise

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Adams, W. C.

    1991-01-01

    We evaluated carotid-cardiac baroreflex responses in eight normotensive men (25-41 yr) on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested before and at 3, 6, 12, 18, and 24 h after graded supine cycle exercise to volitional exhaustion. On another day, this 24-h protocol was repeated with no exercise (control). Beat-to-beat R-R intervals were measured during external application of graded pressures to the carotid sinuses from 40 to -65 mmHg; changes of R-R intervals were plotted against carotid pressure (systolic pressure minus neck chamber pressure). The maximum slope of the response relationship increased (P less than 0.05) from preexercise to 12 h (3.7 +/- 0.4 to 7.1 +/- 0.7 ms/mmHg) and remained significantly elevated through 24 h. The range of the R-R response was also increased from 217 +/- 24 to 274 +/- 32 ms (P less than 0.05). No significant differences were observed during the control 24-h period. An acute bout of graded exercise designed to elicit exhaustion increases the sensitivity and range of the carotid-cardiac baroreflex response for 24 h and enhances its capacity to buffer against hypotension by increasing heart rate. These results may represent an underlying mechanism that contributes to blood pressure stability after intense exercise.

  19. The ANIBES Study on Energy Balance in Spain: Design, Protocol and Methodology

    PubMed Central

    Ruiz, Emma; Ávila, José Manuel; Castillo, Adrián; Valero, Teresa; del Pozo, Susana; Rodriguez, Paula; Bartrina, Javier Aranceta; Gil, Ángel; González-Gross, Marcela; Ortega, Rosa M.; Serra-Majem, Lluis; Varela-Moreiras, Gregorio

    2015-01-01

    Energy Balance (EB) is an important topic to understand how an imbalance in its main determinants (energy intake and consumption) may lead to inappropriate weight gain, considered to be “dynamic” and not “static”. There are no studies to evaluate EB in Spain, and new technologies reveal themselves as key tools to solve common problems to precisely quantify energy consumption and expenditure at population level. The overall purpose of the ANIBES (“Anthropometry, Intake and Energy Balance”) Study was to carry out an accurate updating of food and beverage intake, dietary habits/behaviour and anthropometric data of the Spanish population (9–75 years, n = 2009), as well as the energy expenditure and physical activity patterns. Anthropometry measurements (weight, height, body mass index, waist circumference, % body fat, % body water) were obtained; diet was evaluated throughout a three-day dietary record (tablet device) accompanied by a 24 h-dietary recall; physical activity was quantified by questionnaire and accelerometers were also employed. Finally, information about perception and understanding of several issues related to EB was also obtained. The ANIBES study will contribute to provide valuable useful data to inform food policy planning, food based dietary guidelines development and other health oriented actions in Spain. PMID:25658237

  20. Serotonin and the regulation of mammalian energy balance

    PubMed Central

    Donovan, Michael H.; Tecott, Laurence H.

    2013-01-01

    Maintenance of energy balance requires regulation of the amount and timing of food intake. Decades of experiments utilizing pharmacological and later genetic manipulations have demonstrated the importance of serotonin signaling in this regulation. Much progress has been made in recent years in understanding how central nervous system (CNS) serotonin systems acting through a diverse array of serotonin receptors impact feeding behavior and metabolism. Particular attention has been paid to mechanisms through which serotonin impacts energy balance pathways within the hypothalamus. How upstream factors relevant to energy balance regulate the release of hypothalamic serotonin is less clear, but work addressing this issue is underway. Generally, investigation into the central serotonergic regulation of energy balance has had a predominantly “hypothalamocentric” focus, yet non-hypothalamic structures that have been implicated in energy balance regulation also receive serotonergic innervation and express multiple subtypes of serotonin receptors. Moreover, there is a growing appreciation of the diverse mechanisms through which peripheral serotonin impacts energy balance regulation. Clearly, the serotonergic regulation of energy balance is a field characterized by both rapid advances and by an extensive and diverse set of central and peripheral mechanisms yet to be delineated. PMID:23543912

  1. Top 10 research questions related to energy balance.

    PubMed

    Shook, Robin P; Hand, Gregory A; Blair, Steven N

    2014-03-01

    Obesity is the result of a mismatch between the amount of calories consumed and the amount of calories expended during an extended period of time. This relationship is described by the energy balance equation, which states the rate of change in energy storage depots in the body are equal to the rate of energy intake minus the rate of energy expenditure. Although this relationship may appear easy to understand based on simple mathematics, in reality, a variety of known and unknown systems influence the components of energy balance (energy storage, energy intake, energy expenditure). Clearly, if a complete understanding of energy balance was apparent, worldwide levels of obesity would not have reached pandemic proportions due to effective prevention and treatment strategies. The aim of the present article is to provide a brief overview of the components of energy balance and to identify 10 key topics and unanswered questions that would move the research field forward if addressed. These topics are intentionally diverse and range from general themes (e.g., methodological issues) to specific areas (e.g., intensity of exercise required to alter energy intake). Although this list is not meant to be exhaustive, it does provide a research agenda for scientists involved in the study of energy balance and recommendations for public health professionals developing obesity interventions. PMID:24749236

  2. Intelligent Cooperative MAC Protocol for Balancing Energy Consumption

    NASA Astrophysics Data System (ADS)

    Wu, S.; Liu, K.; Huang, B.; Liu, F.

    To extend the lifetime of wireless sensor networks, we proposed an intelligent balanced energy consumption cooperative MAC protocol (IBEC-CMAC) based on the multi-node cooperative transmission model. The protocol has priority to access high-quality channels for reducing energy consumption of each transmission. It can also balance the energy consumption among cooperative nodes by using high residual energy nodes instead of excessively consuming some node's energy. Simulation results show that IBEC-CMAC can obtain longer network lifetime and higher energy utilization than direct transmission.

  3. Energy balance of trade in New Zealand

    SciTech Connect

    Stephenson, J.; Saha, G.P.

    1980-01-01

    This paper described an analysis made to determine the energy content of New Zealand's imported and exported goods for the year 1976 and the underlying energy imbalance of trade. It is shown that the energy content of imports is considerably higher than that of exports. The difference, expressed as a fraction of net energy consumption, is 16%. The significance of this energy imbalance for the nation's future energy policy and program is discussed. Finally, a normalized GNP/energy use per capita plot, taking into account indirect energy, is presented. Accounting for the energy content of nonenergy trade significantly changes New Zealand's position on the plot. 12 references, 1 figure, 3 tables.

  4. BALANCE

    DOEpatents

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  5. Analysis of energy balance models using the ERBE data set

    NASA Technical Reports Server (NTRS)

    Graves, Charles E.; North, Gerald R.

    1991-01-01

    A review of Energy Balance Models is presented. Results from the Outgoing Longwave Radiation parameterization are discussed. The albedo parameterizations and the consequences of the new parameterizations are examined.

  6. Teaching a Model-based Climatology Using Energy Balance Simulation.

    ERIC Educational Resources Information Center

    Unwin, David

    1981-01-01

    After outlining the difficulties of teaching climatology within an undergraduate geography curriculum, the author describes and evaluates the use of a computer assisted simulation to model surface energy balance and the effects of land use changes on local climate. (AM)

  7. Identification of 24 h Ixodes scapularis immunogenic tick saliva proteins

    PubMed Central

    Lewis, Lauren A.; Radulović, Željko M.; Kim, Tae K.; Porter, Lindsay M.; Mulenga, Albert

    2015-01-01

    Ixodes scapularis is arguably the most medically important tick species in the United States. This tick transmits 5 of the 14 human tick-borne disease (TBD) agents in the USA: Borrelia burgdorferi, Anaplasma phagocytophilum, B. miyamotoi, Babesia microti, and Powassan virus disease. Except for the Powassan virus disease, I. scapularis-vectored TBD agents require more than 24 h post attachment to be transmitted. This study describes identification of 24 h immunogenic I. scapularis tick saliva proteins, which could provide opportunities to develop strategies to stop tick feeding before transmission of the majority of pathogens. A 24 h fed female I. scapularis phage display cDNA expression library was biopanned using rabbit antibodies to 24 h fed I. scapularis female tick saliva proteins, subjected to next generation sequencing, de novo assembly, and bioinformatic analyses. A total of 182 contigs were assembled, of which ~19% (35/182) are novel and did not show identity to any known proteins in GenBank. The remaining ~81% (147/182) of contigs were provisionally identified based on matches in GenBank including ~18% (27/147) that matched protein sequences previously annotated as hypothetical and putative tick saliva proteins. Others include proteases and protease inhibitors (~3%, 5/147), transporters and/or ligand binding proteins (~6%, 9/147), immunogenic tick saliva housekeeping enzyme-like (17%, 25/147), ribosomal protein-like (~31%, 46/147), and those classified as miscellaneous (~24%, 35/147). Notable among the miscellaneous class include antimicrobial peptides (microplusin and ricinusin), myosin-like proteins that have been previously found in tick saliva, and heat shock tick saliva protein. Data in this study provides the foundation for in-depth analysis of I. scapularis feeding during the first 24 h, before the majority of TBD agents can be transmitted. PMID:25825233

  8. Neural Control of Energy Balance: Translating Circuits to Therapies

    PubMed Central

    Gautron, Laurent; Elmquist, Joel K.; Williams, Kevin W.

    2015-01-01

    Recent insights into the neural circuits controlling energy balance and glucose homeostasis have rekindled the hope for development of novel treatments for obesity and diabetes. However, many therapies contribute relatively modest beneficial gains with accompanying side effects, and the mechanisms of action for other interventions remain undefined. This Review summarizes current knowledge linking the neural circuits regulating energy and glucose balance with current and potential pharmacotherapeutic and surgical interventions for the treatment of obesity and diabetes. PMID:25815991

  9. Nitrogen: the key to biofuel energy balance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vigorous debate continues regarding the net energy that can be gained in producing liquid fuels from crop materials. However, it is clear that the net energy gain from the process is small relative to the energy demands of producing the fuel. Thus, a small reduction in the energy required to produ...

  10. Top 10 Research Questions Related to Energy Balance

    ERIC Educational Resources Information Center

    Shook, Robin P.; Hand, Gregory A.; Blair, Steven N.

    2014-01-01

    Obesity is the result of a mismatch between the amount of calories consumed and the amount of calories expended during an extended period of time. This relationship is described by the energy balance equation, which states the rate of change in energy storage depots in the body are equal to the rate of energy intake minus the rate of energy…

  11. Energy Balance Measurement: When Something is Not Better than Nothing

    PubMed Central

    Dhurandhar, Nikhil V.; Schoeller, Dale; Brown, Andrew W.; Heymsfield, Steven B.; Thomas, Diana; Sørensen, Thorkild I.A.; Speakman, John R.; Jeansonne, Madeline; Allison, David B.

    2014-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance are in their infancy, it is unacceptable to use decidedly inaccurate instruments, which may misguide health care policies, future research, and clinical judgment. The scientific and medical communities should discontinue reliance on self-reported EI and PAEE. Researchers and sponsors should develop objective measures of energy balance. PMID:25394308

  12. Energy balance for uranium recovery from seawater

    SciTech Connect

    Schneider, E.; Lindner, H.

    2013-07-01

    The energy return on investment (EROI) of an energy resource is the ratio of the energy it ultimately produces to the energy used to recover it. EROI is a key viability measure for a new recovery technology, particularly in its early stages of development when financial cost assessment would be premature or highly uncertain. This paper estimates the EROI of uranium recovery from seawater via a braid adsorbent technology. In this paper, the energy cost of obtaining uranium from seawater is assessed by breaking the production chain into three processes: adsorbent production, adsorbent deployment and mooring, and uranium elution and purification. Both direct and embodied energy inputs are considered. Direct energy is the energy used by the processes themselves, while embodied energy is used to fabricate their material, equipment or chemical inputs. If the uranium is used in a once-through fuel cycle, the braid adsorbent technology EROI ranges from 12 to 27, depending on still-uncertain performance and system design parameters. It is highly sensitive to the adsorbent capacity in grams of U captured per kg of adsorbent as well as to potential economies in chemical use. This compares to an EROI of ca. 300 for contemporary terrestrial mining. It is important to note that these figures only consider the mineral extraction step in the fuel cycle. At a reference performance level of 2.76 g U recovered per kg adsorbent immersed, the largest energy consumers are the chemicals used in adsorbent production (63%), anchor chain mooring system fabrication and operations (17%), and unit processes in the adsorbent production step (12%). (authors)

  13. Energy Balance and Metabolism after Cancer Treatment

    PubMed Central

    Tonorezos, Emily S.; Jones, Lee W.

    2013-01-01

    Unfavorable physiological, biological, and behavioral alterations during and following treatment for cancer may lead to chronic energy imbalance predisposing to a myriad of deleterious health conditions including obesity, dyslipidemia, and the metabolic syndrome. In addition to the cardiovascular and musculoskeletal effects of these conditions, energy imbalance and metabolic changes after cancer treatment can also affect cancer-related morbidity and mortality. To this end, lifestyle interventions such as diet and physical activity are especially relevant to mitigate the deleterious impact of chronic energy imbalance in cancer survivors. PMID:24331194

  14. The Global Energy Balance of Titan

    NASA Technical Reports Server (NTRS)

    Li, Liming; Nixon, Conor A.; Achterberg, Richard K.; Smith, Mark A.; Gorius, Nicolas J. P.; Jiang, Xun; Conrath, Barney J.; Gierasch, Peter J.; Simon-Miller, Amy A.; Flasar, F. Michael; Baines, Kevin H.; Ingersoll, Andrew P.; West, Robert A.; Vasavada, Ashwin R.; Ewald, Shawn P.

    2011-01-01

    We report the first measurement of the global emitted power of Titan. Longterm (2004-2010) observations conducted by the Composite Infrared Spectrometer (CIRS) onboard Cassini reveal that the total emitted power by Titan is (2.84 plus or minus 0.01) x 10(exp 8) watts. Together with previous measurements of the global absorbed solar power of Titan, the CIRS measurements indicate that the global energy budget of Titan is in equilibrium within measurement error. The uncertainty in the absorbed solar energy places an upper limit on the energy imbalance of 5.3%.

  15. Isospin effects on the mass dependence of the balance energy

    SciTech Connect

    Gautam, Sakshi; Sood, Aman D.

    2010-07-15

    We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/A= 0.54 and 0.57 as well as isobaric systems with N/A= 0.5 and 0.58. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

  16. Free energy balance in gyrokinetic turbulence

    SciTech Connect

    Banon Navarro, A.; Morel, P.; Albrecht-Marc, M.; Carati, D.; Merz, F.; Goerler, T.; Jenko, F.

    2011-09-15

    Free energy plays an important role in gyrokinetic theory, since it is known to be a nonlinear invariant. Its evolution equations are derived and analyzed for the case of ion temperature gradient driven turbulence, using the formalism adopted in the Gene code. In particular, the ion temperature gradient drive, the collisional dissipation as well as entropy/electrostatic energy transfer channels represented by linear curvature and parallel terms are analyzed in detail.

  17. Alterations in energy balance following exenatide administration.

    PubMed

    Bradley, David P; Kulstad, Roger; Racine, Natalie; Shenker, Yoram; Meredith, Melissa; Schoeller, Dale A

    2012-10-01

    Exenatide is a medication similar in structure and effect to native glucagon-like peptide-1, an incretin hormone with glucose-lowering properties. The aim of the study was to measure the change in total energy expenditure (TEE) and body composition during exenatide administration and by deduction the relative contributions of energy expenditure and energy intake to exenatide-induced weight loss. Forty-five obese (body mass index, 30-40 kg·m⁻²) subjects were identified. After exclusion criteria application, 28 subjects entered into the study and 18 subjects (12 female, 6 male) completed the study, which consisted of 6 visits over 14 weeks and injection of exenatide for an average of 84 ± 5 days. Respiratory gas analysis and doubly labeled water measurements were performed before initiation of exenatide and after approximately 3 months of exenatide administration. The average weight loss from the beginning of injection period to the end of the study in completed subjects was 2.0 ± 2.8 kg (p = 0.01). Fat mass declined by 1.3 ± 1.8 kg (p = 0.01) while the fat-free mass trended downward but was not significant (0.8 ± 2.2 kg, p = 0.14). There was no change in weight-adjusted TEE (p = 0.20), resting metabolic rate (p = 0.51), or physical activity energy expenditure (p = 0.38) and no change in the unadjusted thermic effect of a meal (p = 0.37). The significant weight loss because of exenatide administration was thus the result of decreasing energy intake. In obese nondiabetic subjects, exenatide administration did not increase TEE and by deduction the significant weight loss and loss of fat mass was due to decreased energy intake. PMID:22735035

  18. Energy balance: an overview with emphasis on children.

    PubMed

    Tam, Charmaine S; Ravussin, Eric

    2012-01-01

    Childhood obesity is a significant public health problem, affecting one in five children in the United States. At the crux of this issue is a dysregulation of energy intake and energy expenditure. This review will provide an overview on energy and nutrient balance. We discuss energy balance studies in children using indirect and direct measures, and focus particularly on obesity as a deleterious consequence in childhood survivors of cancer. Obesity affects 11-57% of children with acute lymphoblastic leukemia, probably due to increased energy intake and reduced energy expenditure secondary to reduced habitual activity caused by fatigue. However, most of the studies in children with leukemia are retrospective, use BMI as a measure of obesity, and are inconclusive about the impact of the type of treatment on the development of obesity later in life. To better understand the etiology of obesity in both healthy and sick children, we need to undertake nutrient balance studies with appropriate measures of fat mass and fat distribution while keeping in mind the influence of normal tissue growth and puberty on energy balance. PMID:22021150

  19. Dietary(sensory)variety and energy balance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of overweight and obesity in US adults is currently 68%, compared with about 47% in the early 1970s. Many dietary factors have been proposed to contribute to the US obesity epidemic, including the percentage of energy intake from fat, carbohydrate and protein; glycemic index; fruit a...

  20. Evaluation of surface energy and radiation balance systems for FIFE

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Qian, Ping

    1988-01-01

    The energy balance and radiation balance components were determined at six sites during the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) conducted south of Manhattan, Kansas during the summer of 1987. The objectives were: to determine the effect of slope and aspect, throughout a growing season, on the magnitude of the surface energy balance fluxes as determined by the Energy Balance Method (EBM); to investigate the calculation of the soil heat flux density at the surface as calculated from the heat capacity and the thermal conductivity equations; and to evaluate the performance of the Surface Energy and Radiation Balance System (SERBS). A total of 17 variables were monitored at each site. They included net, solar (up and down), total hemispherical (up and down), and diffuse radiation, soil temperature and heat flux density, air and wet bulb temperature gradients, wind speed and direction, and precipitation. A preliminary analysis of the data, for the season, indicate that variables including net radiation, air temperature, vapor pressure, and wind speed were quite similar at the sites even though the sites were as much as 16 km apart and represented four cardinal slopes and the top of a ridge.

  1. Melanocortin receptors as drug targets for disorders of energy balance.

    PubMed

    Adan, Roger A H; van Dijk, Gertjan

    2006-06-01

    There is overwhelming evidence that the brain melanocortin system is a key regulator of energy balance, and dysregulations in the brain melanocortin system can lead to obesity. The melanocortin system is one of the major downstream leptin signaling pathways in the brain. In contrast to leptin, preclinical studies indicate that diet-induced obese animals are still responsive to the anorectic effects of melanocortin receptor agonists, suggesting the melanocortin system is an interesting therapeutic opportunity. Besides regulating energy balance, melanocortins are involved in a variety of other neuroendocrine processes, including inflammation, blood pressure regulation, addictive and sexual behavior, and sensation of pain. This review evaluates the melanocortin system function from the perspective to use specific melanocortin (MC) receptors as drug targets, with a focus on the treatment of obesity and eating disorders in humans, and the implications this may have on mechanisms beyond the control of energy balance. PMID:16787227

  2. Development of Energy Balances for the State of California

    SciTech Connect

    Murtishaw, Scott; Price, Lynn; de la Rue du Can, Stephane; Masanet, Eric; Worrell, Ernst; Sahtaye, Jayant

    2005-12-01

    Analysts assessing energy policies and energy modelers forecasting future trends need to have access to reliable and concise energy statistics. Lawrence Berkeley National Laboratory evaluated several sources of California energy data, primarily from the California Energy Commission and the U.S. Energy Information Administration, to develop the California Energy Balance Database (CALEB). This database manages highly disaggregated data on energy supply, transformation, and end-use consumption for each type of energy commodity from 1990 to the most recent year available (generally 2001) in the form of an energy balance, following the methodology used by the International Energy Agency. This report presents the data used for CALEB and provides information on how the various data sources were reconciled. CALEB offers the possibility of displaying all energy flows in numerous ways (e.g.,physical units, Btus, petajoules, different levels of aggregation), facilitating comparisons among the different types of energy commodities and different end-use sectors. In addition to displaying energy data, CALEB can also be used to calculate state-level energy-related carbon dioxide emissions using the methodology of the Intergovernmental Panel on Climate Change.

  3. Disruptions in Energy Balance: Does Nature overcome Nurture?

    PubMed Central

    Fernández, José R.; Casazza, Krista; Divers, Jasmin; López-Alarcón, Mardya

    2008-01-01

    Fat accumulation, in general, is the result of a breakdown in the homeostatic regulation of energy balance. Although, the specific factors influencing the disruption of energy balance and why these factors affect individuals differently are not completely understood, numerous studies have identified multiple contributors. Environmental components influence food acquisition, eating, and lifestyle habits. However, the variability in obesity-related outcomes observed among individuals placed in similar controlled environments support the notion that genetic components also wield some control. Multiple genetic regions have been associated with measures related to energy balance; however, the replication of these genetic contributors to energy intake and energy expenditure in humans is relatively small perhaps because of the heterogeneity of human populations. Genetic tools such as genetic admixture account for individual’s genetic background in gene association studies, reducing the confounding effect of population stratification, and promise to be a relevant tool on the identification of genetic contributions to energy balance, particularly among individuals of diverse racial/ethnic backgrounds. Although it has been recognized that genes are expressed according to environmental influences, the search toward the understanding of nature and nurture in obesity will require the detailed study of the effect of genes under diverse physiologic and behavioral environments. It is evident that more research is needed to elucidate the methodological and statistical issues that underlie the interactions between genes and environments in obesity and its related comorbidities. PMID:18096193

  4. ISEE observations of the magnetopause - Reconnection and the energy balance

    NASA Technical Reports Server (NTRS)

    Paschmann, G.; Papamastorakis, I.; Sckopki, N.; Sonnerup, B. U. O.; Bame, S. J.

    1985-01-01

    The total energy balance for two events with the objective of obtaining check on the interpretation in terms of reconnection is examined. To within experimental uncertainties, the plasma and magnetic field data are consistent with reconnection. An enthalpy increase comparable to the kinetic energy increase occurs in the magnetopause. Thus substantial dissipation is present in the rotational discontinuity. An ion heat flow associated with a beam of reflected magnetosheath particles carried away some 20 percent of the total converted electromagnetic energy.

  5. Energy balance in solar and stellar chromospheres

    NASA Technical Reports Server (NTRS)

    Avrett, E. H.

    1981-01-01

    Net radiative cooling rates for quiet and active regions of the solar chromosphere and for two stellar chromospheres are calculated from corresponding atmospheric models. Models of chromospheric temperature and microvelocity distributions are derived from observed spectra of a dark point within a cell, the average sun and a very bright network element on the quiet sun, a solar plage and flare, and the stars Alpha Boo and Lambda And. Net radiative cooling rates due to the transitions of various atoms and ions are then calculated from the models as a function of depth. Large values of the net radiative cooling rate are found at the base of the chromosphere-corona transition region which are due primarily to Lyman alpha emission, and a temperature plateau is obtained in the transition region itself. In the chromospheric regions, the calculated cooling rate is equal to the mechanical energy input as a function of height and thus provides a direct constraint on theories of chromospheric heating.

  6. Fat intake and energy-balance effects.

    PubMed

    Westerterp-Plantenga, M S

    2004-12-30

    This paper focuses on the effects of dietary fats or fatty acids on key targets of metabolic intermediates for body-weight control, i.e. satiety, thermogenesis, fat oxidation and body composition. With respect to sensory satiety, it appeared, e.g. that linoleic acid tasters showed a different mechanism for meal termination than non-tasters did. They stopped eating linoleic acid containing food based upon satiety, whereas the non-tasters stopped eating based upon the change in pleasantness of taste. Moreover, in the normal range of body mass index, an inverse relationship was shown between % 'tasters' and BMI. In a high fat diet vs. a low fat high protein high carbohydrate diet, metabolic satiety appeared to be continuously lower and correlated positively to diet-induced energy expenditure. However, with respect to the intermeal interval, satiety appeared to be more sustained following a high fat vs. a high CHO preload, resulting in a lower meal frequency. Covert fat replacement during breakfast by sucrose polyester was successful in combination with dietary restraint, yet overt fat replacement in snacks was successful in the dietary-unrestrained subjects, i.e. those who habitually ate snacks. With respect to fat oxidation, from a respiration-chamber experiment on the effects of diacylglycerol compared (DG) to triacylglycerol (TG) intake, it was concluded that consumption of DG increased fat oxidation and beta-hydroxy-butyrate levels, but did not affect energy metabolism or triacylglycerol level. Parameters of appetite were all lowered by DG compared to TG. With respect to body composition, the effects of 13 weeks CLA supplementation in overweight subjects during weight regain were assessed. Although CLA did not affect %body-weight regain, the regain of fat-free mass was increased by CLA, independently of %body-weight regain and physical activity, and as a consequence resting metabolic rate was increased. At the same time, appetite was reduced and satiety and

  7. Energy balancing by fat Pik3ca.

    PubMed

    Nelson, Victoria Lb; Ballou, Lisa M; Lin, Richard Z

    2015-01-01

    Obesity is often associated with systemic insulin resistance, and the decline of insulin sensitivity marks the progression of obesity into a disease state. We recently generated a mouse with adipose-specific ablation of the p110α phosphoinositide 3-kinase (PI3K) catalytic subunit to model insulin resistance in this organ. The phenotypes of this animal revealed novel roles of adipose PI3K signaling in regulating body weight and systemic glucose and lipid homeostasis. Loss of p110α in the brown adipose tissue resulted in reduced expression of mitochondrial-associated genes and decreased respiration in brown adipocytes. Reduced activity of the brown adipose tissue in p110α-null mice lowered their energy expenditure, which promoted obesity and systemic metabolic dysfunction with increased lipid deposition in the liver. Loss of PI3K activity did not affect adiposity until sexual maturation, suggesting that the effect of adipose PI3K on obesity might be linked to the development of puberty. Elevated leptin in the p110α knockout mice might interfere with the reproductive axis to delay pubertal development. The increase in adiposity induced by adipose-specific loss of p110α provides a link between insulin resistance and obesity onset and may also provide deeper insight into changes in prepubescent insulin sensitivity that can affect metabolism later in life. PMID:26167406

  8. Energy balancing by fat Pik3ca

    PubMed Central

    Nelson, Victoria LB; Ballou, Lisa M; Lin, Richard Z

    2014-01-01

    Obesity is often associated with systemic insulin resistance, and the decline of insulin sensitivity marks the progression of obesity into a disease state. We recently generated a mouse with adipose-specific ablation of the p110α phosphoinositide 3-kinase (PI3K) catalytic subunit to model insulin resistance in this organ. The phenotypes of this animal revealed novel roles of adipose PI3K signaling in regulating body weight and systemic glucose and lipid homeostasis. Loss of p110α in the brown adipose tissue resulted in reduced expression of mitochondrial-associated genes and decreased respiration in brown adipocytes. Reduced activity of the brown adipose tissue in p110α-null mice lowered their energy expenditure, which promoted obesity and systemic metabolic dysfunction with increased lipid deposition in the liver. Loss of PI3K activity did not affect adiposity until sexual maturation, suggesting that the effect of adipose PI3K on obesity might be linked to the development of puberty. Elevated leptin in the p110α knockout mice might interfere with the reproductive axis to delay pubertal development. The increase in adiposity induced by adipose-specific loss of p110α provides a link between insulin resistance and obesity onset and may also provide deeper insight into changes in prepubescent insulin sensitivity that can affect metabolism later in life. PMID:26167406

  9. Pedometer and Human Energy Balance Applications for Science Instruction

    ERIC Educational Resources Information Center

    Rye, James A.; Smolski, Stefan

    2007-01-01

    Teachers can use pedometers to facilitate inquiry learning and show students the need for mathematics in scientific investigation. The authors conducted activities with secondary students that investigated intake and expenditure components of the energy balance algorithm, which led to inquiries about pedometers and related data. By investigating…

  10. Determining aerodynamic conductance of spar chambers from energy balance measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aerodynamic conductance (gA) of SPAR chambers was determined from measurements of energy balance and canopy temperature over a peanut canopy. gA was calculated from the slope of sensible heat flux (H) versus canopy-to-air temperature difference. H and the canopy-to-air temperature were varied by...

  11. Intergenerational Energy Balance Interventions: A Systematic Literature Review

    ERIC Educational Resources Information Center

    Swanson, Mark; Studts, Christina R.; Bardach, Shoshana H.; Bersamin, Andrea; Schoenberg, Nancy E.

    2011-01-01

    Many nations have witnessed a dramatic increase in the prevalence of obesity and overweight across their population. Recognizing the influence of the household environment on energy balance has led many researchers to suggest that intergenerational interventions hold promise for addressing this epidemic. Yet few comprehensive reviews of…

  12. Mass and energy balance of the cold Io torus

    NASA Technical Reports Server (NTRS)

    Moreno, M. A.; Barbosa, D. D.

    1986-01-01

    A new model of the cold Io torus is described. Ions and energy are injected into the system by independent processes so that the mass balance is isolated from the energy balance. The primary source of energy is local ionization and acceleration of hot pickup ions resulting from charge exchange between thermal ions and an extended cloud of Iogenic sulfur and oxygen atoms. The primary energy loss mechanism of the plasma is collisionally excited line emission at optical wavelengths. The primary ion source is radial diffusion inward from the hot torus on a time scale of 140-710 days. The primary ion loss mechanism is a novel two-step enhanced recombination mechanism involving charge exchange between thermal ions and an extended cloud of neutral SO2 molecules, followed by rapid dissociative recombination of the resultant molecular ion. The model provides a self-consistent solution which reconciles a number of diverse observations with known physical processes.

  13. Dynamical horizons: energy, angular momentum, fluxes, and balance laws.

    PubMed

    Ashtekar, Abhay; Krishnan, Badri

    2002-12-23

    Dynamical horizons are considered in full, nonlinear general relativity. Expressions of fluxes of energy and angular momentum carried by gravitational waves across these horizons are obtained. Fluxes are local, the energy flux is positive, and change in the horizon area is related to these fluxes. The flux formulas also give rise to balance laws analogous to the ones obtained by Bondi and Sachs at null infinity and provide generalizations of the first and second laws of black-hole mechanics. PMID:12484807

  14. Assessment of Global Annual Atmospheric Energy Balance from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Stackhouse, Paul; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang (Alice); Hinkelman, Laura

    2008-01-01

    Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface and latent and sensible heat over oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimations. Global annual means of the TOA net radiation obtained from both direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 Watts per square meter, respectively. The estimated atmospheric and surface heat imbalances are about -8 9 Watts per square meter, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated at about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements significantly reduces the bias errors in the observed global energy budgets of the climate system.

  15. Assessment of global annual atmospheric energy balance from satellite observations

    NASA Astrophysics Data System (ADS)

    Lin, Bing; Stackhouse, Paul W.; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang; Hinkelman, Laura M.

    2008-08-01

    Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface as well as latent and sensible heat over the oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimates. Global annual means of the TOA net radiation obtained from both satellite direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 W/m2, respectively. The estimated atmospheric and surface heat imbalances are about -8 and 9 W/m2, respectively, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and the likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget: the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements has significantly reduced the bias errors in the observed global energy budgets of the climate system.

  16. Balancing

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    At many occasions we are asked to achieve a “balance” in our lives: when it comes, for example, to work and food. Balancing is crucial in game design as well as many have pointed out. In games with a meaningful purpose, however, balancing is remarkably different. It involves the balancing of three different worlds, the worlds of Reality, Meaning, and Play. From the experience of designing Levee Patroller, I observed that different types of tensions can come into existence that require balancing. It is possible to conceive of within-worlds dilemmas, between-worlds dilemmas, and trilemmas. The first, the within-world dilemmas, only take place within one of the worlds. We can think, for example, of a user interface problem which just relates to the world of Play. The second, the between-worlds dilemmas, have to do with a tension in which two worlds are predominantly involved. Choosing between a cartoon or a realistic style concerns, for instance, a tension between Reality and Play. Finally, the trilemmas are those in which all three worlds play an important role. For each of the types of tensions, I will give in this level a concrete example from the development of Levee Patroller. Although these examples come from just one game, I think the examples can be exemplary for other game development projects as they may represent stereotypical tensions. Therefore, to achieve harmony in any of these forthcoming games, it is worthwhile to study the struggles we had to deal with.

  17. Global Sea Level Rise and the Earth's Energy Balance

    NASA Astrophysics Data System (ADS)

    Willis, J.; Hobbs, W. R.

    2012-12-01

    As the oceans warm due to human-caused climate change, they contribute to both global and regional sea level rise. But the uptake of heat by the ocean also reflects the net radiative imbalance of the planet due to human interference with the climate. Global sea level rise and its components therefore provide a constraint on the Earth's Energy Balance, and vice versa. We will present an assessment of the sea level and energy budgets and their implications for the magnitude of deep ocean warming and net radiative forcing over the past decade. Observations from satellite altimeters and the GRACE gravity mission will be compared with in situ observations of ocean warming. In addition, we will consider observations from the Clouds and the Earth's Radiant Energy System (CERES) instruments to assess the Earth's net radiation balance. Finally, a new estimate of bias corrections for the XBT observations will be assessed and presented.

  18. Low protein diets produce divergent effects on energy balance.

    PubMed

    Pezeshki, Adel; Zapata, Rizaldy C; Singh, Arashdeep; Yee, Nicholas J; Chelikani, Prasanth K

    2016-01-01

    Diets deficient in protein often increase food consumption, body weight and fat mass; however, the underlying mechanisms remain poorly understood. We compared the effects of diets varying in protein concentrations on energy balance in obesity-prone rats. We demonstrate that protein-free (0% protein calories) diets decreased energy intake and increased energy expenditure, very low protein (5% protein) diets increased energy intake and expenditure, whereas moderately low protein (10% protein) diets increased energy intake without altering expenditure, relative to control diet (15% protein). These diet-induced alterations in energy expenditure are in part mediated through enhanced serotonergic and β-adrenergic signaling coupled with upregulation of key thermogenic markers in brown fat and skeletal muscle. The protein-free and very low protein diets decreased plasma concentrations of multiple essential amino acids, anorexigenic and metabolic hormones, but these diets increased the tissue expression and plasma concentrations of fibroblast growth factor-21. Protein-free and very low protein diets induced fatty liver, reduced energy digestibility, and decreased lean mass and body weight that persisted beyond the restriction period. In contrast, moderately low protein diets promoted gain in body weight and adiposity following the period of protein restriction. Together, our findings demonstrate that low protein diets produce divergent effects on energy balance. PMID:27122299

  19. Low protein diets produce divergent effects on energy balance

    PubMed Central

    Pezeshki, Adel; Zapata, Rizaldy C.; Singh, Arashdeep; Yee, Nicholas J.; Chelikani, Prasanth K.

    2016-01-01

    Diets deficient in protein often increase food consumption, body weight and fat mass; however, the underlying mechanisms remain poorly understood. We compared the effects of diets varying in protein concentrations on energy balance in obesity-prone rats. We demonstrate that protein-free (0% protein calories) diets decreased energy intake and increased energy expenditure, very low protein (5% protein) diets increased energy intake and expenditure, whereas moderately low protein (10% protein) diets increased energy intake without altering expenditure, relative to control diet (15% protein). These diet-induced alterations in energy expenditure are in part mediated through enhanced serotonergic and β-adrenergic signaling coupled with upregulation of key thermogenic markers in brown fat and skeletal muscle. The protein-free and very low protein diets decreased plasma concentrations of multiple essential amino acids, anorexigenic and metabolic hormones, but these diets increased the tissue expression and plasma concentrations of fibroblast growth factor-21. Protein-free and very low protein diets induced fatty liver, reduced energy digestibility, and decreased lean mass and body weight that persisted beyond the restriction period. In contrast, moderately low protein diets promoted gain in body weight and adiposity following the period of protein restriction. Together, our findings demonstrate that low protein diets produce divergent effects on energy balance. PMID:27122299

  20. Energy Balance in DC Arc Plasma Melting Furnace

    NASA Astrophysics Data System (ADS)

    Zhao, Peng; Meng, Yuedong; Yu, Xinyao; Chen, Longwei; Jiang, Yiman; Ni, Guohua; Chen, Mingzhou

    2009-04-01

    In order to treat hazardous municipal solid waste incinerator's (MSWI) fly ash, a new DC arc plasma furnace was developed. Taking an arc of 100 V/1000 A DC as an example, the heat transfer characteristics of the DC arc plasma, ablation of electrodes, heat properties of the fly ash during melting, heat transfer characteristics of the flue gas, and heat loss of the furnace were analyzed based on the energy conservation law, so as to achieve the total heat information and energy balance during plasma processing, and to provide a theoretical basis for an optimized design of the structure and to improve energy efficiency.

  1. Canopy radiation transmission for an energy balance snowmelt model

    NASA Astrophysics Data System (ADS)

    Mahat, Vinod; Tarboton, David G.

    2012-01-01

    To better estimate the radiation energy within and beneath the forest canopy for energy balance snowmelt models, a two stream radiation transfer model that explicitly accounts for canopy scattering, absorption and reflection was developed. Upward and downward radiation streams represented by two differential equations using a single path assumption were solved analytically to approximate the radiation transmitted through or reflected by the canopy with multiple scattering. This approximation results in an exponential decrease of radiation intensity with canopy depth, similar to Beer's law for a deep canopy. The solution for a finite canopy is obtained by applying recursive superposition of this two stream single path deep canopy solution. This solution enhances capability for modeling energy balance processes of the snowpack in forested environments, which is important when quantifying the sensitivity of hydrologic response to input changes using physically based modeling. The radiation model was included in a distributed energy balance snowmelt model and results compared with observations made in three different vegetation classes (open, coniferous forest, deciduous forest) at a forest study area in the Rocky Mountains in Utah, USA. The model was able to capture the sensitivity of beneath canopy net radiation and snowmelt to vegetation class consistent with observations and achieve satisfactory predictions of snowmelt from forested areas from parsimonious practically available information. The model is simple enough to be applied in a spatially distributed way, but still relatively rigorously and explicitly represent variability in canopy properties in the simulation of snowmelt over a watershed.

  2. Energy expenditure and balance during spaceflight on the space shuttle

    NASA Technical Reports Server (NTRS)

    Stein, T. P.; Leskiw, M. J.; Schluter, M. D.; Hoyt, R. W.; Lane, H. W.; Gretebeck, R. E.; LeBlanc, A. D.

    1999-01-01

    The objectives of this study were as follows: 1) to measure human energy expenditure (EE) during spaceflight on a shuttle mission by using the doubly labeled water (DLW) method; 2) to determine whether the astronauts were in negative energy balance during spaceflight; 3) to use the comparison of change in body fat as measured by the intake DLW EE, 18O dilution, and dual energy X-ray absorptiometry (DEXA) to validate the DLW method for spaceflight; and 4) to compare EE during spaceflight against that found with bed rest. Two experiments were conducted: a flight experiment (n = 4) on the 16-day 1996 life and microgravity sciences shuttle mission and a 6 degrees head-down tilt bed rest study with controlled dietary intake (n = 8). The bed rest study was designed to simulate the flight experiment and included exercise. Two EE determinations were done before flight (bed rest), during flight (bed rest), and after flight (recovery). Energy intake and N balance were monitored for the entire period. Results were that body weight, water, fat, and energy balance were unchanged with bed rest. For the flight experiment, decreases in weight (2.6 +/- 0.4 kg, P < 0.05) and N retention (-2. 37 +/- 0.45 g N/day, P < 0.05) were found. Dietary intake for the four astronauts was reduced in flight (3,025 +/- 180 vs. 1,943 +/- 179 kcal/day, P < 0.05). EE in flight was 3,320 +/- 155 kcal/day, resulting in a negative energy balance of 1,355 +/- 80 kcal/day (-15. 7 +/- 1.0 kcal. kg-1. day-1, P < 0.05). This corresponded to a loss of 2.1 +/- 0.4 kg body fat, which was within experimental error of the fat loss determined by 18O dilution (-1.4 +/- 0.5 kg) and DEXA (-2.4 +/- 0.4 kg). All three methods showed no change in body fat with bed rest. In conclusion, 1) the DLW method for measuring EE during spaceflight is valid, 2) the astronauts were in severe negative energy balance and oxidized body fat, and 3) in-flight energy (E) requirements can be predicted from the equation: E = 1.40 x resting

  3. Observations in energy balance in man during spaceflight

    NASA Technical Reports Server (NTRS)

    Rambaut, P. C.; Leach, C. S.; Leonard, J. I.

    1977-01-01

    An investigation was undertaken of the changes in metabolic energy balance which occur in weightlessness. Daily energy intake was determined each day throughout the 28-, 59-, and 84-day flights for each of the nine Skylab astronauts. The energy content of the urine and feces was also measured. Changes in body composition were inferred from measurements of weight, volume, water, and total exchangeable potassium before and after flight. During flight, changes were followed by a daily measurement of body mass and by metabolic balance. Examination of the data reveal losses in body weight during the 1st and 2nd months of flight, a loss in body water and protein during the 1st month and a loss of fat during the 1st, 2nd, and 3rd months of flight. The energy input was about 41.7 kcal/kg per day on the ground, and 43.7 kcal/kg per day after 3 months in space. The increase in net energy input of about 1.6% per month is significant (P less than 0.05). When the net energy input is expressed on the basis of total body potassium, the increase in the resulting normalized net energy input of about 3.7% per month is also significant (P less than 0.05).

  4. Surface energy and radiation balance systems - General description and improvements

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Simpson, James R.

    1989-01-01

    Surface evaluation of sensible and latent heat flux densities and the components of the radiation balance were desired for various vegetative surfaces during the ASCOT84 experiment to compare with modeled results and to relate these values to drainage winds. Five battery operated data systems equipped with sensors to determine the above values were operated for 105 station days during the ASCOT84 experiment. The Bowen ratio energy balance technique was used to partition the available energy into the sensible and latent heat flux densities. A description of the sensors and battery operated equipment used to collect and process the data is presented. In addition, improvements and modifications made since the 1984 experiment are given. Details of calculations of soil heat flow at the surface and an alternate method to calculate sensible and latent heat flux densities are provided.

  5. Validation of two energy balance closure parameterisations using field measurements

    NASA Astrophysics Data System (ADS)

    Eder, Fabian; De Roo, Frederik; Kohnert, Katrin; Desjardins, Raymond L.; Foken, Thomas; Schmid, Hans Peter; Mauder, Matthias

    2013-04-01

    Eddy Covariance (EC) measurements often do not close the energy balance. This indicates that surface heat fluxes are underestimated, likely because large-scale eddies and stationary circulations are not captured. Because EC is a widespread tool in environmental science to assess energy fluxes and trace gas budgets, it is essential to quantify the 'missing' fluxes. In the literature, two approaches to parameterise the lack of energy balance closure can be found. The first one by Huang et al (2008) is based on large-eddy simulations (LES) and perceives the energy imbalance as being the result of large-scale turbulent organized structures. The second approach by Panin and Bernhofer (2008) suggests an empirical approach which focuses on surface roughness heterogeneities on the landscape-scale. We tested both approaches with EC data from three sites, located in southern Germany, of the Terrestrial Environmental Observatories (TERENO) programme. Additionally, we applied the parameterisations to aircraft data from Canada, which were conducted as part of the Boreal Ecosystem-Atmosphere Study (BOREAS) experiment and the Boreal Ecosystem Research and Monitoring Sites (BERMS) programme. For each flight, the flux contribution of turbulent structures larger than 2 km, determined by wavelet analysis, serves as an estimate of the missing flux of conventional EC measurements. In most cases, the two parameterisations do not give a reliable prediction of the energy balance residual. The approach of Panin and Bernhofer (2008) disregards topographical effects, differences in surface moisture and surface temperature and thus, it cannot explain the poor energy balance closure of the TERENO sites. However, above the flat terrain of the airborne measurements in Canada, it works surprisingly well. The parameterisation by Huang et al (2008) was developed for homogeneous terrain, a condition which is almost never met in field studies. In addition, there is a general mismatch between LES and

  6. Battery model for electrical power system energy balance

    NASA Technical Reports Server (NTRS)

    Hafen, D. P.

    1983-01-01

    A model to simulate nickel-cadmium battery performance and response in a spacecraft electrical power system energy balance calculation was developed. The voltage of the battery is given as a function of temperature, operating depth-of-charge (DOD), and battery state-of-charge. Also accounted for is charge inefficiency. A battery is modeled by analysis of the results of a multiparameter battery cycling test at various temperatures and DOD's.

  7. Components of surface energy balance in a temperate grassland ecosystem

    NASA Technical Reports Server (NTRS)

    Kim, Joon; Verma, Shashi B.

    1990-01-01

    Eddy correlation measurements of moisture, heat, and momentum fluxes were made at a tall grassland site in Kansas during the First International Satellite Land Surface Climatology Project Field Experiment. The fluxes, stomatal conductance, and leaf water potential of three grass species are reported. The species are big bluestem, indiangrass, and switchgrass. The daily and seasonal variation in the components of the surface energy balance and the aerodynamic and canopy surface conductances for prairie vegetation are examined.

  8. Energy Balance, Climate, and Life - Work of M. Budyko

    NASA Technical Reports Server (NTRS)

    Cahalan, Robert F.

    2004-01-01

    This talk will review the work of Mikhail I. Budyko, author of "Climate and Life" and many other works, who died recently at age 81, in St Petersburg, Russia. He directed the Division for Climate Change Research at the State Hydrological Institute. We will explore Budyko's work in clarifying the role of energy balance in determining planetary climate, and the role of climate in regulating Earth s biosphere.

  9. Irreversibility in energy processes: Non-dimensional quantification and balance

    NASA Astrophysics Data System (ADS)

    Pons, Michel

    2004-06-01

    The concept of thermodynamic efficiency (ratio of real cycle efficiency by Carnot efficiency) is well-known. The concept of numbers of entropy-production and of exergy-loss proposed by A. Bejan are also known, but rarely used. The present study firstly evidences that these two last numbers are actually identical, thus being a common number of irreversibility, independent of the method used for obtaining it. The study also evidences a non-dimensional irreversibility balance that applies to any energy conversion process. This balance correlates the thermodynamic efficiency of a whole process (which in most cases equals the exergetic efficiency) and the numbers of irreversibility of the different components or sub-processes involved in this process. Moreover, the basic additivity of entropy-productions and exergy-losses is maintained in this balance. This balance applies to the basic cycles (heat-engines, refrigerators, heat-pumps and heat-transformers), either work- or heat-powered. It also applies to more complex cycles (heat-powered cycles consuming electricity, four-temperature heat-powered cycles, cogeneration processes), thus giving a robust framework for analyzing these cycles.

  10. Toward energy-aware balancing of mobile graphics

    NASA Astrophysics Data System (ADS)

    Stavrakis, Efstathios; Polychronis, Marios; Pelekanos, Nectarios; Artusi, Alessandro; Hadjichristodoulou, Panayiotis; Chrysanthou, Yiorgos

    2015-03-01

    In the area of computer graphics the design of hardware and software has primarily been driven by the need to achieve maximum performance. Energy efficiency was usually neglected, assuming that a stable always-on power source was available. However, the advent of the mobile era has brought into question these ideas and designs in computer graphics since mobile devices are both limited by their computational capabilities and their energy sources. Aligned to this emerging need in computer graphics for energy efficiency analysis we have setup a software framework to obtain power measurements from 3D scenes using off-the-shelf hardware that allows for sampling the energy consumption over the power rails of the CPU and GPU. Our experiments include geometric complexity, texture resolution and common CPU and GPU workloads. The goal of this work is to combine the knowledge obtained from these measurements into a prototype energy-aware balancer of processing resources. The balancer dynamically selects the rendering parameters and uses a simple framerate-based dynamic frequency scaling strategy. Our experimental results demonstrate that our power saving framework can achieve savings of approximately 40%.

  11. Dietary energy balance modulates ovarian cancer progression and metastasis

    PubMed Central

    Al-Wahab, Zaid; Tebbe, Calvin; Chhina, Jasdeep; Dar, Sajad A.; Morris, Robert T.; Ali-Fehmi, Rouba; Giri, Shailendra; Munkarah, Adnan R.; Rattan, Ramandeep

    2014-01-01

    A high energy balance, or caloric excess, accounts as a tumor promoting factor, while a negative energy balance via caloric restriction, has been shown to delay cancer progression. The effect of energy balance on ovarian cancer progression was investigated in an isogeneic immunocompetent mouse model of epithelial ovarian cancer kept on a regimen of regular diet, high energy diet (HED) and calorie restricted diet (CRD), prior to inoculating the animals intraperitoneally with the mouse ovarian surface epithelial ID8 cancer cells. Tumor evaluation revealed that mice group on HED displayed the most extensive tumor formation with the highest tumor score at all organ sites (diaphragm, peritoneum, bowel, liver, kidney, spleen), accompanied with increased levels of insulin, leptin, insulin growth factor-1 (IGF-1), monocyte chemoattractant protein-1 (MCP-1), VEGF and interleukin 6 (IL-6). On the other hand, the mice group on CRD exhibited the least tumor burden associated with a significant reduction in levels of insulin, IGF-1, leptin, MCP-1, VEGF and IL-6. Immunohistochemistry analysis of tumors from HED mice showed higher activation of Akt and mTOR with decreased adenosine monophosphate activated kinase (AMPK) and SIRT1 activation, while tumors from the CRD group exhibited the reverse profile. In conclusion, ovarian cancer growth and metastasis occurred more aggressively under HED conditions and was significantly curtailed under CRD. The suggested mechanism involves modulated secretion of growth factors, cytokines and altered regulation of AMPK and SIRT1 that converges on mTOR inhibition. While the role of a high energy state in ovarian cancer has not been confirnmed in the literature, the current findings support investigating the potential impact of diet modulation as adjunct to other anticancer therapies and as possible individualized treatment strategy of epithelial ovarian cancer. PMID:25026276

  12. Gender Differences in Insulin Resistance, Body Composition, and Energy Balance

    PubMed Central

    Geer, Eliza B.; Shen, Wei

    2010-01-01

    Background Men and women differ substantially in regard to degrees of insulin resistance, body composition, and energy balance. Adipose tissue distribution, in particular the presence of elevated visceral and hepatic adiposity, plays a central role in the development of insulin resistance and obesity-related complications. Objective This review summarizes published data on gender differences in insulin resistance, body composition, and energy balance, to provide insight into novel gender-specific avenues of research as well as gender-tailored treatments of insulin resistance, visceral adiposity, and obesity. Methods English-language articles were identified from searches of the PubMed database through November 2008, and by reviewing the references cited in these reports. Searches included combinations of the following terms: gender, sex, insulin resistance, body composition, energy balance, and hepatic adipose tissue. Results For a given body mass index, men were reported to have more lean mass, women to have higher adiposity. Men were also found to have more visceral and hepatic adipose tissue, whereas women had more peripheral or subcutaneous adipose tissue. These differences, as well as differences in sex hormones and adipokines, may contribute to a more insulin-sensitive environment in women than in men. When normalized to kilograms of lean body mass, men and women had similar resting energy expenditure, but physical energy expenditure was more closely related to percent body fat in men than in women. Conclusion Greater amounts of visceral and hepatic adipose tissue, in conjunction with the lack of a possible protective effect of estrogen, may be related to higher insulin resistance in men compared with women. PMID:19318219

  13. Hippocampal lipoprotein lipase regulates energy balance in rodents☆

    PubMed Central

    Picard, Alexandre; Rouch, Claude; Kassis, Nadim; Moullé, Valentine S.; Croizier, Sophie; Denis, Raphaël G.; Castel, Julien; Coant, Nicolas; Davis, Kathryn; Clegg, Deborah J.; Benoit, Stephen C.; Prévot, Vincent; Bouret, Sébastien; Luquet, Serge; Le Stunff, Hervé; Cruciani-Guglielmacci, Céline; Magnan, Christophe

    2013-01-01

    Brain lipid sensing is necessary to regulate energy balance. Lipoprotein lipase (LPL) may play a role in this process. We tested if hippocampal LPL regulated energy homeostasis in rodents by specifically attenuating LPL activity in the hippocampus of rats and mice, either by infusing a pharmacological inhibitor (tyloxapol), or using a genetic approach (adeno-associated virus expressing Cre-GFP injected into Lpllox/lox mice). Decreased LPL activity by either method led to increased body weight gain due to decreased locomotor activity and energy expenditure, concomitant with increased parasympathetic tone (unchanged food intake). Decreased LPL activity in both models was associated with increased de novo ceramide synthesis and neurogenesis in the hippocampus, while intrahippocampal infusion of de novo ceramide synthesis inhibitor myriocin completely prevented body weight gain. We conclude that hippocampal lipid sensing might represent a core mechanism for energy homeostasis regulation through de novo ceramide synthesis. PMID:24634821

  14. Seasonal Contrasts in the Surface Energy Balance of the Sahel

    SciTech Connect

    Miller, Ron; Slingo, A.; Barnard, James C.; Kassianov, Evgueni I.

    2009-03-14

    Over most of the world ocean, heating of the surface by sunlight is balanced predominately by evaporative cooling. Even over land, moisture for evaporation is available from vegetation or the soil reservoir. However, at the ARM Mobile Facility in Niamey, Niger, soil moisture is so depleted that evaporation makes a significant contribution to the surface energy balance only at the height of the rainy season, when precipitation has replenished the soil reservoir. Using observations at the Mobile Facility from late 2005 to early 2007, we describe how the surface balances radiative forcing. How the surface compensates time-averaged solar heating varies with seasonal changes in atmospheric water vapor, which modulates the greenhouse effect and the ability of the surface to radiate thermal energy directly to space. During the dry season, sunlight is balanced mainly by longwave radiation and the turbulent flux of sensible heat. The ability of longwave radiation to cool the surface drops after the onset of the West African summer monsoon, when moist, oceanic air flows onshore, increasing local column moisture and atmospheric opacity at these wavelengths. After the monsoon onset, but prior to significant rainfall, solar heating is compensated mainly by the sensible heat flux. During the rainy season, the magnitude of evaporation is initially controlled by the supply of moisture from precipitation. However, by the height of the rainy season, sufficient precipitation has accumulated at the surface that evaporation is related to the flux demanded by solar radiation, and radiative forcing of the surface is balanced comparably by the latent, sensible, and longwave fluxes. Radiative forcing of the surface also varies on a subseasonal time scale due to fluctuations in water vapor, clouds, and aerosol concentration. Except at the height of the rainy season, subseasonal forcing is balanced mainly by sensible heating and longwave anomalies. The efficacy of the sensible heat flux

  15. The energy balance of plasmoids in the solar atmosphere

    NASA Technical Reports Server (NTRS)

    Cargill, P. J.; Pneuman, G. W.

    1986-01-01

    The properties of an isolated magnetized plasmoid in a nonuniform magnetic field such as arises in stellar atmospheres are studied. The work of Pneuman and Cargill (1985) on the so-called melon-seed effect is extended to include an equation describing the energy balance, so giving a unified picture of the shape, motion, and energetics of the plasmoid. Three treatments of plasmoid energy balance are considered: (1) a polytropic law, (P = about N to the gamma); (2) one in which the plasmoid cools radiatively; and (3) one in which a heating function proportional to the local density balances the radiation. For a gamma = 4/3 polytrope the evolution is self-similar, so that the plasmoid maintains its shape as it moves out from the stellar surface. If gamma is less than 4/3, the final shape is a long thin cigar-shaped body, whereas if gamma is greater than or equal to 4/3, it ultimately becomes self-similar. In cases with radiation and also with heating, the ultimate shape of the plasmoid is determined by whether its gas or magnetic pressure dominate. The former is equivalent to the gamma-less-than-4/3 polytrope, and the latter to the gamma-greater-than-4/3 one. If radiation alone is present, the plasmoid cools rapidly and subsequently evolves self-similarly. If heating balances radiation initially, then the plasmoid heats up as it moves out, but, if the ratio of the transit of time of Alfven waves across it is much less than the radiative cooling time, it ultimately evolves as a gamma = 5/3 polytrope. In each case the plasmoid can be ejected to large distances (several radii) in a stellar atmosphere, for a reasonable choice of surface parameters.

  16. Appetite control and energy balance: impact of exercise.

    PubMed

    Blundell, J E; Gibbons, C; Caudwell, P; Finlayson, G; Hopkins, M

    2015-02-01

    Exercise is widely regarded as one of the most valuable components of behaviour that can influence body weight and therefore help in the prevention and management of obesity. Indeed, long-term controlled trials show a clear dose-related effect of exercise on body weight. However, there is a suspicion, particularly fuelled by media reports, that exercise serves to increase hunger and drive up food intake thereby nullifying the energy expended through activity. Not everyone performing regular exercise will lose weight and several investigations have demonstrated a huge individual variability in the response to exercise regimes. What accounts for this heterogeneous response? First, exercise (or physical activity) through the expenditure of energy will influence the energy balance equation with the potential to generate an energy deficit. However, energy expenditure also influences the control of appetite (i.e. the physiological and psychological regulatory processes underpinning feeding) and energy intake. This dynamic interaction means that the prediction of a resultant shift in energy balance, and therefore weight change, will be complicated. In changing energy intake, exercise will impact on the biological mechanisms controlling appetite. It is becoming recognized that the major influences on the expression of appetite arise from fat-free mass and fat mass, resting metabolic rate, gastric adjustment to ingested food, changes in episodic peptides including insulin, ghrelin, cholecystokinin, glucagon-like peptide-1 and tyrosine-tyrosine, as well as tonic peptides such as leptin. Moreover, there is evidence that exercise will influence all of these components that, in turn, will influence the drive to eat through the modulation of hunger (a conscious sensation reflecting a mental urge to eat) and adjustments in postprandial satiety via an interaction with food composition. The specific actions of exercise on each physiological component will vary in strength from

  17. Alternative energy balances for Bulgaria to mitigate climate change

    NASA Astrophysics Data System (ADS)

    Christov, Christo

    1996-01-01

    Alternative energy balances aimed to mitigate greenhouse gas (GHG) emissions are developed as alternatives to the baseline energy balance. The section of mitigation options is based on the results of the GHG emission inventory for the 1987 1992 period. The energy sector is the main contributor to the total CO2 emissions of Bulgaria. Stationary combustion for heat and electricity production as well as direct end-use combustion amounts to 80% of the total emissions. The parts of the energy network that could have the biggest influence on GHG emission reduction are identified. The potential effects of the following mitigation measures are discussed: rehabilitation of the combustion facilities currently in operation; repowering to natural gas; reduction of losses in thermal and electrical transmission and distribution networks; penetration of new combustion technologies; tariff structure improvement; renewable sources for electricity and heat production; wasteheat utilization; and supply of households with natural gas to substitute for electricity in space heating and cooking. The total available and the achievable potentials are estimated and the implementation barriers are discussed.

  18. [Energy balance, body composition and the female athlete triad syndrome].

    PubMed

    Weinstein, Yitzhak; Weinstein, Ayelet

    2012-02-01

    With the rising participation of women in sports events, the prevalence of eating disorders and the female athlete triad (FTS), a syndrome of disordered eating, amenorrhea, and osteoporosis, have also increased in recent years. FTS is often seen in sports that emphasize thinness (e.g. gymnastics, figure skating and dancing) and also in endurance events. Elements of the FTS are pathophysiologically linked, leading to several disease risks and even to mortality. In spite of the considerable knowledge about sports nutrition, there is no consensus as to the correct nutrition regime for the female athlete. There is consensus that minimizing fluctuations in 'target-body-weight' is an indication of a long-term energy balance. Female athletes (e.g. in endurance events and gymnastics) are less likely to achieve the recommended carbohydrates (CHO) and fat consumption due to chronic or episodic constraints of total energy intake while struggling to achieve or maintain low levels of body fat. It is recommended that dietary CHO and fat content be increased to preserve fat-free mass thus enhancing health and performance. Energy balance should also be maintained during recesses. Furthermore, within-day episodes of energy deficits/surplus (measured by the frequency and/or magnitude of the episodes) should be monitored and treated closest to the time of the incidents. PMID:22741211

  19. Energy and Mass Balance At Gran Campo Nevado, Patagonia, Chile

    NASA Astrophysics Data System (ADS)

    Schneider, C.; Kilian, R.; Casassa, G.

    The Gran Campo Nevado (GCN) Ice Cap on Peninsula Muñoz Gamero, Chile, is lo- cated in the southernmost part of the Patagonian Andes at 53S. It comprises an ice cap and numerous outlet glaciers which mostly end in proglacial lakes at sea level. The total ice covered area sums up to approximately 250 km2. GCN forms the only major ice body between the Southern Patagonian Icefield and the Street of Magallan. Its almost unique location in the zone of the all-year westerlies makes it a region of key interest in terms of glacier and climate change studies of the westwind zone of the Southern Hemisphere. Mean annual temperature of approximately +5C at sea level and high precipitation of about 8.000 mm per year lead to an extreme turn-over of ice mass from the accumulation area of the GCN Ice Cap to the ablation areas of the outlet glaciers. Since October 1999 an automated weather station (AWS) is run continuously in the area at Bahia Bahamondes for monitoring climate parameters. From February to April 2000 an additional AWS was operated on Glaciar Lengua a small outlet glacier of GCN to the north-west. Ablation has been measured at stakes during the same pe- riod. The aim of this study, was to obtain point energy and mass balance on Glaciar Lengua. The work was conducted as part of the international and interdisciplinary working group SGran Campo NevadoT and supported by the German Research Foun- & cedil;dation (DFG). Energy balance was calculated using the bulk approach formulas and calibrated to the measured ablation. It turns out, that sensible heat transfer is the major contribution to the energy balance. Since high cloud cover rates prevail, air tempera- ture is the key factor for the energy balance of the glacier. Despite high rain fall rates, energy input from rain fall is of only minor importance to the overall energy balance. From the energy balance computed, it was possible to derive summer-time degree-day factors for Glaciar Lengua. With data from the nearby

  20. Energy balance framework for Net Zero Energy buildings

    EPA Science Inventory

    Approaching a Net Zero Energy (NZE) building goal based on current definitions is flawed for two principal reasons - they only deal with energy quantities required for operations, and they do not establish a threshold, which ensures that buildings are optimized for reduced consum...

  1. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    PubMed

    Wohlfahrt, Georg; Widmoser, Peter

    2013-02-15

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements. PMID:24465072

  2. Recycling legislation: A balanced approach for opening biomass energy opportunities

    SciTech Connect

    Easterly, J.L.

    1995-09-01

    State recycling legislation represents one of the barriers to using wood wastes for energy. Although many states are setting recycling goals that often mandate a significant portion of the waste stream be recycled, legislation in the same states specifically excludes wood-to-energy as a recycling option. A significant supply of yard waste and wood waste could be available for biomass power generation of recycling legislation credited the use of wood-to-energy as an acceptable recycling alternative. This article discusses in some detail the approach Florida legislation has pursued. It could be a model for other innovative recycling programs. It provides checks and balances as well as reasonable compromises that help to avoid or minimize objections by the environmental community.

  3. Energy balance and ovulation: small cages versus natural habitats.

    PubMed

    Bronson, F H

    1998-01-01

    In the laboratory, ovulation is suppressed when a mammal is in negative energy balance whether that state is caused by inadequate food intake, excessive locomotor activity or heavy thermoregulatory costs. In this paper, knowledge generated in the laboratory about the link between ovulation and energy balance is examined in relation to the kinds of energetic challenges mammals actually face in natural habitats. When viewed in that context, several conclusions can be drawn. First, females ovulate whenever extant energetic conditions permit unless the process is blocked by non-metabolic stress, social cues or a predictive seasonal cue such as photoperiod. In the latter case, most mammals show at least a seasonal tendency in their reproduction and the majority do not use a predictive cue; they reproduce opportunistically in relation to seasonal variation in the energetic characteristics of their environment. Second, the widely held assumption that a female's fat reserves must exceed a critical level in order that she may ovulate finds no support in the literature dealing with natural populations. Third, the surprisingly rapid responsiveness of the gonadotrophin releasing hormone (GnRH) pulse generator to energetic manipulation probably reflects the study of animals that are in a pure survival mode. Fourth, the complexity of the energetic challenges mammals face in the wild suggests that there are probably multiple metabolic and neural pathways coupling ovulation to energy balance and that these pathways are probably characterized by considerable overlap and redundancy. Thus, fifth, to develop a more realistic overview of these pathways there is a need for experimental designs that present mammals with the kinds of complex challenges they actually face in the wild habitats in which they evolved. PMID:9801265

  4. Urban Energy Balance Measurements During CalNex 2010

    NASA Astrophysics Data System (ADS)

    Vogel, C. A.; Pendergrass, W.

    2010-12-01

    A fundamental component to understanding air quality and air-surface exchange in urban environments is to understand the turbulent flow characteristics just above the canopy, and the local forcings which drive the exchange process. Studies have indicated UCP (urban canopy parameterization) may have significant ramifications for air-quality modeling because the dynamic characteristics of this volume into which pollutants are injected has been altered. Turbulent fluxes of momentum, heat, moisture, and other scalars of interest, need to be addressed for this complex setting, as well as other quantities involved in the surface energy balance. Further, in modeling the transport of chemical species fundamental scales of turbulent flow must either be directly measured or parameterized. The CalNex 2010 study provided an opportunity to satisfy a number of requirements for obtaining urban canopy model parameter data for mesoscale models in an alternate urban environment from ATDD's urban DCNet National Capital Region program. Specifically, within the CalNex science questions, these data address concerns of potential major deficiencies in the representation of chemistry and meteorology processes in research and operational models and support model development through the collection of additional measurements as well as defining physical and chemical processes not well captured by available models. NOAA/ATDD deployed an energy-balance flux system at the CalNex 2010 Pasadena , CA urban supersite. The e-balance system was roof-top mounted on the California Institute of Technology Keck Building in association with the CalNex urban particulate sampling effort. Observation of energy budgets were obtained between May 16 and June 16, 2010. Initial analysis has focused on evaluating sensible heat flux and determining an estimate for thermal roughness . Coupling of sampled rooftop skin temperatures, ambient temperatures, sensible heat flux, and friction coefficient provides an

  5. Amylin-mediated control of glycemia, energy balance, and cognition.

    PubMed

    Mietlicki-Baase, Elizabeth G

    2016-08-01

    Amylin, a peptide hormone produced in the pancreas and in the brain, has well-established physiological roles in glycemic regulation and energy balance control. It improves postprandial blood glucose levels by suppressing gastric emptying and glucagon secretion; these beneficial effects have led to the FDA-approved use of the amylin analog pramlintide in the treatment of diabetes mellitus. Amylin also acts centrally as a satiation signal, reducing food intake and body weight. The ability of amylin to promote negative energy balance, along with its unique capacity to cooperatively facilitate or enhance the intake- and body weight-suppressive effects of other neuroendocrine signals like leptin, have made amylin a leading target for the development of novel pharmacotherapies for the treatment of obesity. In addition to these more widely studied effects, a growing body of literature suggests that amylin may play a role in processes related to cognition, including the neurodegeneration and cognitive deficits associated with Alzheimer's disease (AD). Although the function of amylin in AD is still unclear, intriguing recent reports indicate that amylin may improve cognitive ability and reduce hallmarks of neurodegeneration in the brain. The frequent comorbidity of diabetes mellitus and obesity, as well as the increased risk for and occurrence of AD associated with these metabolic diseases, suggests that amylin-based pharmaceutical strategies may provide multiple therapeutic benefits. This review will discuss the known effects of amylin on glycemic regulation, energy balance control, and cognitive/motivational processes. Particular focus will be devoted to the current and/or potential future clinical use of amylin pharmacotherapies for the treatment of diseases in each of these realms. PMID:26922873

  6. Surface Energy and Water Balance for the Arkansas-Red River Basin from the ECMWF Reanalysis.

    NASA Astrophysics Data System (ADS)

    Betts, Alan K.; Viterbo, Pedro; Wood, Eric

    1998-11-01

    Average surface energy and water budgets, subsurface variables, and atmospheric profiles were computed online with an hourly timescale from the ECMWF reanalysis for five subbasins of the Mississippi River from 1985-93. The results for the Arkansas-Red River basin are discussed on diurnal, 5-day, monthly, seasonal, and interannual timescales, and compared with the observed basin-scale precipitation and streamflow. The model shows the seasonal and interannual variability of precipitation, evaporation, and soil water. The annual range of soil water is typically 100 mm, and the interannual range is somewhat smaller. The model has a significant spinup of about 29% in precipitation from the analysis cycle to a 12-24-h forecast. The spinup of the model `large-scale' precipitation is 39%, double that of the spinup of the model `convective' precipitation of 18%. When compared with 5-day and monthly basin averages of hourly rain gauge observations (corrected for a probable 10% low bias), the precipitation in the reanalysis is low by 20%-25%, while the 12-24-h forecast precipitation is high by about 5%; so the model precipitation estimates the bracket observations. The nudging of soil water in the analysis cycle, based on 0-6-h forecast errors in low-level humidity, plays an important role in the model liquid hydrology. It prevents the downward interannual drift of soil water, associated with a shortfall of precipitation in the analysis cycle, while allowing interannual variations of soil water. However, the nudging appears to be trying to compensate for other errors in the model: such as errors in the diurnal cycle of low-level mixing ratio and in the seasonal cycle of evaporation. Evaporation in the model is probably high in winter, and on an annual basis may have a small high bias in comparison to a basin evaporation estimate derived from observed precipitation and streamflow. An internal inconsistency of 7% in the evaporation term in the model surface energy and

  7. Primary cilia in energy balance signaling and metabolic disorder

    PubMed Central

    Lee, Hankyu; Song, Jieun; Jung, Joo Hyun; Ko, Hyuk Wan

    2015-01-01

    Energy homeostasis in our body system is maintained by balancing the intake and expenditure of energy. Excessive accumulation of fat by disrupting the balance system causes overweight and obesity, which are increasingly becoming global health concerns. Understanding the pathogenesis of obesity focused on studying the genes related to familial types of obesity. Recently, a rare human genetic disorder, ciliopathy, links the role for genes regulating structure and function of a cellular organelle, the primary cilium, to metabolic disorder, obesity and type II diabetes. Primary cilia are microtubule based hair-like membranous structures, lacking motility and functions such as sensing the environmental cues, and transducing extracellular signals within the cells. Interestingly, the subclass of ciliopathies, such as Bardet-Biedle and Alström syndrome, manifest obesity and type II diabetes in human and mouse model systems. Moreover, studies on genetic mouse model system indicate that more ciliary genes affect energy homeostasis through multiple regulatory steps such as central and peripheral actions of leptin and insulin. In this review, we discuss the latest findings in primary cilia and metabolic disorders, and propose the possible interaction between primary cilia and the leptin and insulin signal pathways which might enhance our understanding of the unambiguous link of a cell’s antenna to obesity and type II diabetes. [BMB Reports 2015; 48(12): 647-654] PMID:26538252

  8. Life cycle assessment of biofuels: energy and greenhouse gas balances.

    PubMed

    Gnansounou, E; Dauriat, A; Villegas, J; Panichelli, L

    2009-11-01

    The promotion of biofuels as energy for transportation in the industrialized countries is mainly driven by the perspective of oil depletion, the concerns about energy security and global warming. However due to sustainability constraints, biofuels will replace only 10 to 15% of fossil liquid fuels in the transport sector. Several governments have defined a minimum target of GHG emissions reduction for those biofuels that will be eligible to public incentives, for example a 35% emissions reduction in case of biofuels in Members States of the European Union. This article points out the significant biases in estimating GHG balances of biofuels stemming from modelling choices about system definition and boundaries, functional unit, reference systems and allocation methods. The extent to which these choices influence the results is investigated. After performing a comparison and constructive criticism of various modelling choices, the LCA of wheat-to-bioethanol is used as an illustrative case where bioethanol is blended with gasoline at various percentages (E5, E10 and E85). The performance of these substitution options is evaluated as well. The results show a large difference in the reduction of the GHG emissions with a high sensitivity to the following factors: the method used to allocate the impacts between the co-products, the type of reference systems, the choice of the functional unit and the type of blend. The authors come out with some recommendations for basing the estimation of energy and GHG balances of biofuels on principles such as transparency, consistency and accuracy. PMID:19553106

  9. The Precession Index and a Nonlinear Energy Balance Climate Model

    NASA Technical Reports Server (NTRS)

    Rubincam, David

    2004-01-01

    A simple nonlinear energy balance climate model yields a precession index-like term in the temperature. Despite its importance in the geologic record, the precession index e sin (Omega)S, where e is the Earth's orbital eccentricity and (Omega)S is the Sun's perigee in the geocentric frame, is not present in the insolation at the top of the atmosphere. Hence there is no one-for-one mapping of 23,000 and 19,000 year periodicities from the insolation to the paleoclimate record; a nonlinear climate model is needed to produce these long periods. A nonlinear energy balance climate model with radiative terms of form T n, where T is surface temperature and n less than 1, does produce e sin (omega)S terms in temperature; the e sin (omega)S terms are called Seversmith psychroterms. Without feedback mechanisms, the model achieves extreme values of 0.64 K at the maximum orbital eccentricity of 0.06, cooling one hemisphere while simultaneously warming the other; the hemisphere over which perihelion occurs is the cooler. In other words, the nonlinear energy balance model produces long-term cooling in the northern hemisphere when the Sun's perihelion is near northern summer solstice and long-term warming in the northern hemisphere when the aphelion is near northern summer solstice. (This behavior is similar to the inertialess gray body which radiates like T 4, but the amplitude is much lower for the energy balance model because of its thermal inertia.) This seemingly paradoxical behavior works against the standard Milankovitch model, which requires cool northern summers (Sun far from Earth in northern summer) to build up northern ice sheets, so that if the standard model is correct it must be more efficient than previously thought. Alternatively, the new mechanism could possibly be dominant and indicate southern hemisphere control of the northern ice sheets, wherein the southern oceans undergo a long-term cooling when the Sun is far from the Earth during northern summer. The cold

  10. Hypothalamic miRNAs: emerging roles in energy balance control

    PubMed Central

    Schneeberger, Marc; Gomez-Valadés, Alicia G.; Ramirez, Sara; Gomis, Ramon; Claret, Marc

    2015-01-01

    The hypothalamus is a crucial central nervous system area controlling appetite, body weight and metabolism. It consists in multiple neuronal types that sense, integrate and generate appropriate responses to hormonal and nutritional signals partly by fine-tuning the expression of specific batteries of genes. However, the mechanisms regulating these neuronal gene programmes in physiology and pathophysiology are not completely understood. MicroRNAs (miRNAs) are key regulators of gene expression that recently emerged as pivotal modulators of systemic metabolism. In this article we will review current evidence indicating that miRNAs in hypothalamic neurons are also implicated in appetite and whole-body energy balance control. PMID:25729348

  11. Evolution effects on parton energy loss with detailed balance

    SciTech Connect

    Cheng Luan; Wang Enke

    2010-07-15

    The initial conditions in the chemically nonequilibrated medium and Bjorken expanding medium at Relativistic Heavy Ion Collider (RHIC) are determined. With a set of rate equations describing the chemical equilibration of quarks and gluons based on perturbative QCD, we investigate the consequence for parton evolution at RHIC. With considering parton evolution, it is shown that the Debye screening mass and the inverse mean free-path of gluons reduce with increasing proper time in the QGP medium. The parton evolution affects the parton energy loss with detailed balance, both parton energy loss from stimulated emission in the chemically nonequilibrated expanding medium and in Bjorken expanding medium are linear dependent on the propagating distance rather than square dependent in the static medium. The energy absorption cannot be neglected at intermediate jet energies and small propagating distance of the energetic parton in contrast with that it is important only at intermediate jet energy in the static medium. This will increase the energy and propagating distance dependence of the parton energy loss and will affect the shape of suppression of moderately high P{sub T} hadron spectra.

  12. Energy balance and dietary habits of America's Cup sailors.

    PubMed

    Bernardi, Elisabetta; Delussu, Sofia A; Quattrini, Filippo M; Rodio, Angelo; Bernardi, Marco

    2007-08-01

    This research, which was conducted with crew members of an America's Cup team, had the following objectives: (a) to assess energy expenditure and intake during training; (b) to evaluate the sailors' diet, and (c) to identify any dietary flaws to determine the appropriate intake of nutrients, correct possible dietary mistakes, and improve their food habits. Energy expenditure was estimated on 15 sailors using direct measurements (oxygen consumption) and a 3-day activity questionnaire. Oxygen consumption was measured on sailors during both on-water America's Cup sailing training and dry-land fitness training. Composition of the diet was estimated using a 3-day food record. Average daily energy expenditure of the sailors ranged from 14.95 to 24.4 MJ, depending on body mass and boat role, with the highest values found in grinders and mastmen. Daily energy intake ranged from 15.7 to 23.3 MJ (from +6% to -18% of energy expenditure). The contributions of carbohydrate, protein, and fat to total energy intake were 43%, 18%, and 39% respectively, values that are not in accord with the recommended guidelines for athletes. Our results show the importance of assessing energy balance and food habits for America's Cup sailors performing different roles. The practical outcome of this study was that the sailors were given dietary advice and prescribed a Mediterranean diet, explained in specific nutrition lectures. PMID:17613739

  13. Mass and energy balance in the 1973 August 9 flare

    NASA Technical Reports Server (NTRS)

    Dere, K. P.; Cook, J. W.

    1983-01-01

    The mass and energy balance of the thermal plasma during the decay phase of the solar flare of August 9, 1973, are studied. The analysis is based on observationally determined values for the differential emission measure, density, turbulent and bulk velocities, and physical dimensions. The total particle content and total thermal energy content of the flare plasmas with temperatures above 100,000 K and their variation with time are calculated. The particle loss and the energy losses through radiation, conduction, and convection are evaluated. The decrease in total particle content can be accounted for by the convective losses through the loop footprints at 100,000 K. Radiation is the dominant energy loss mechanism although convective losses at 100,000 K can be important. Conductive losses at 100,000 K into cooler chromospheric material appear to be negligible. The decrease in the total energy content during the decay phase is equal to the sum of the energy losses over the period of observation. No requirement is found for continued heating during the decay phase.

  14. The structure and energy balance of cool star atmospheres

    NASA Technical Reports Server (NTRS)

    Linsky, J. L.

    1982-01-01

    The atmospheric structure and energy balance phenomena associated with magnetic fields in the Sun are reviewed and it is shown that similar phenomena occur in cool stars. The evidence for the weakening or disappearance of transition regions and coronae is discussed together with the appearance of extended cool chromospheres with large mass loss, near V-R = 0.80 in the H-R diagram. Like the solar atmosphere, these atmospheres are not homogeneous and there is considerable evidence for plage regions with bright TR emission lines that overlie dark (presumably magnetic) star spots. The IUE observations are providing important information on the energy balance in these atmospheres that should guide theoretical calculations of the nonradiative heating rate. Recent high dispersion spectra are providing unique information concerning which components of close binary systems are the dominant contributors to the observed emission. A recent unanticipated discovery is that the transition lines are redshifted (an antiwind) in DRa (G2 Ib) and perhaps other stars. Finally, the G and K giants and supergiants are classified into three groups depending on whether their atmospheres are dominated by closed magnetic flux tubes, open field geometries, or a predominately open geometry with a few closed flux tubes embedded.

  15. Modelling The Energy And Mass Balance Of A Black Glacier

    NASA Astrophysics Data System (ADS)

    Grossi, G.; Taschner, S.; Ranzi, R.

    A distributed energy balance hydrologic model has been implemented to simulate the melting season of the Belvedere glacier, situated in the Anza river basin (North- Western Italy) for a few years. The Belvedere Glacier is an example of SblackS glacier, ´ since the ablation zone is covered by a significant debris layer. The glacierSs termi- nus has an altitude of 1785 m asl which is very unusual for the Southern side of the European Alps. The model accounts for the energy exchange processes at the inter- face between the atmospheric boundary layer and the snow/ice/debris layer. To run the model hydrometeorological and physiographic data were collected, including the depth of the debris cover and the tritium (3H) concentration in the glacial river. Mea- surements of the soil thermal conductivity were carried out during a field campaign organised within the glaciers monitoring GLIMS project, at the time of the passage of the Landsat and the Terra satellites last 15 August 2001. A comparison of the different energy terms simulated by the model assigns a dominant role to the shortwave radia- tion, which provides the highest positive contribution to the energy available for snow- and ice-melt, while the sensible heat turns out to be the second major source of heat. Longwave radiation balance and latent heat seem to be less relevant and often nega- tive. The role of the debris cover is not negligible, since its thermal insulation causes, on average, a decrease in the ice melt volume. One of the model variables is the tem- perature of the debris cover, which can be a useful information when a black glacier is to be monitored through remote sensing techniques. The visible and near infrared radi- ation data do not always provide sufficient information to detect the glaciers' margins beneath the debris layer. For this reason the information of the different thermal sur- face characteristics (pure ice, debris covered ice, rock), proved by the energy balance model results was

  16. Surface heat flux data from energy balance Bowen ratio systems

    SciTech Connect

    Wesely, M.L.; Cook, D.R.; Coulter, R.L.

    1995-06-01

    The 350 {times} 400 km domain of the Atmospheric Radiation Measurement (ARM) Program`s Clouds and Radiation Testbed (CART) site in the southern Great Plains is equipped with 10 energy balance Bowen ratio (EBBR) stations at grassland sites; they measure the net radiation, ground heat flux, and temperature/humidity differences between 1.0 and 2.0 m heights. The latter differences provide estimates of the geometric Bowen ratio ({beta}), which are used to estimate sensible and latent heat fluxes. This paper addresses the problem that occurs when the value of {beta} is near {minus}1 and to demonstrate the effectiveness of the EBBR stations in collecting energy flux data at the CART site.

  17. Pedometer and Human Energy Balance Applications for Science Instruction

    PubMed Central

    Rye, James A.; Smolski, Stefan

    2008-01-01

    Teachers can use pedometers to facilitate inquiry learning and show students the need for mathematics in scientific investigation. The authors conducted activities with secondary students that investigated intake and expenditure components of the energy balance algorithm, which led to inquiries about pedometers and related data. By investigating the accuracy of pedometers and variables that may impact reported step counts, students can better understand experimental design and statistical concepts. Students can also examine other data (distance walked, kilocalories expended) using multifunction pedometers and apply the concepts of correlation and regression. This topic fits well with thematic learning and responds to concerns about excess energy intake and insufficient physical activity in the U.S. population. PMID:19081754

  18. Simulating the surface energy balance in a soybean canopy with SHAW and RZ-SHAW models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Correct simulation of surface energy balance in a crop canopy is critical for better understanding of soil water balance, canopy and soil temperature, plant water stress, and plant growth. One existing effort is to incorporate the surface energy balance in the Simultaneous Heat And Water (SHAW) into...

  19. Surface Energy Balance Methods for Evapotranspiration - Some Enhancements and Applications

    NASA Astrophysics Data System (ADS)

    Gutschick, V. P.; Wang, J.; Sammis, T. W.

    2007-05-01

    Satellite-received radiances and auxiliary ground-based information are routinely used to estimate the evapotranspiration rate (ET, or LE as a latent heat energy flux density) on landscape elements. Many methods compute LE as a residual, computing the terms Rn, G, and H in the full energy-balance equation, S = Rn - G ¬ H - LE, where S is surface (canopy) heat storage (often assumed near zero), Rn is net radiation, G is heat flux into the (soil) surface, and H is the sensible heat flux. Computation of H is prone to errors in obtaining accurate radiometric temperatures, TR, of the surface and in relating TR to the true kinetic temperature of the surface heat source. The Surface Energy BAlance Land (SEBAL) method avoids the offset errors by introducing an assumption of a linear relation of TR to the surface-to-air temperature difference. This assumption, and several others, can introduce distinct errors and operational problems, which will be discussed, along with several improvements under development. The latter include direct regression solutions for LE, correcting for advection of energy and for the lapse rate of the surface (not air) temperature, and the use of auxiliary radiance-based information on vegetation water stress. Also to be discussed are potential applications of enhanced ET methods to estimate hydrologic redistributions (runon, runoff), the consequent spatial patterning of vegetation, and the implications of both for ecological studies (equilibrium canopy development, long-term acclimation of stomatal control) and ecosystem management (estimating forest water stress and its relations to stand density, forest thinning exercises, and hazards of fire and insect outbreaks).

  20. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA) to estimate actual evapotranspiration under complex terrain

    NASA Astrophysics Data System (ADS)

    Gao, Z. Q.; Liu, C. S.; Gao, W.; Chang, N. B.

    2010-07-01

    Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial scales. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at varying temporal and spatial scales under complex terrain. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA). With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM), and the vegetation cover derived from satellite images, the SEBTA can fully account for the dynamic impacts of complex terrain and changing land cover in concert with some varying kinetic parameters (i.e., roughness and zero-plane displacement) over time. Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  1. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA) to estimate actual evapotranspiration over heterogeneous terrain

    NASA Astrophysics Data System (ADS)

    Gao, Z. Q.; Liu, C. S.; Gao, W.; Chang, N.-B.

    2011-01-01

    Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial coverage in the study areas. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at different temporal and spatial scales under heterogeneous terrain with varying elevations, slopes and aspects. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA). With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM), and the vegetation cover derived from satellite images, the SEBTA can account for the dynamic impacts of heterogeneous terrain and changing land cover with some varying kinetic parameters (i.e., roughness and zero-plane displacement). Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.

  2. Nqrs Data for C24H44CuI2N [C24H44N·1/2(Cu2I4)] (Subst. No. 1588)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H44CuI2N [C24H44N·1/2(Cu2I4)] (Subst. No. 1588)

  3. Capsaicin increases sensation of fullness in energy balance, and decreases desire to eat after dinner in negative energy balance.

    PubMed

    Janssens, Pilou L H R; Hursel, Rick; Westerterp-Plantenga, Margriet S

    2014-06-01

    Addition of capsaicin (CAPS) to the diet has been shown to increase satiety; therefore, CAPS is of interest for anti-obesity therapy. We investigated the effects of CAPS on appetite profile and ad libitum energy intake in relation to energy balance. Fifteen subjects (seven women and eight men, age: 29.7 ± 10.8yrs, BMI: 23.3 ± 2.9 kg/m(2)) underwent four conditions in a randomized crossover design in 36 hour sessions in a respiration chamber; they received 100% of their daily energy requirements in the conditions "100%Control" and "100%CAPS", and 75% of their daily energy requirements in the conditions "75%Control" and "75%CAPS", followed by an ad libitum dinner. In the 100%CAPS and 75%CAPS conditions, CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units) with every meal. Satiety (P < 0.05) and fullness (P = 0.01) were measured every waking hour and before and after every meal using visual analogue scales, and were higher in the 100%CAPS versus 100%Control condition. After dinner desire to eat, satiety and fullness did not differ between 75%CAPS and 100%Control, while desire to eat was higher (P < 0.05) and satiety (P = 0.06) and fullness (P = 0.06) tended to be lower in the 75%Control versus 100%Control condition. Furthermore, ad libitum intake (P = 0.07) and overconsumption (P = 0.06) tended to decrease in 100%CAPS versus 100%Control. In energy balance, addition of capsaicin to the diet increases satiety and fullness, and tends to prevent overeating when food intake is ad libitum. After dinner, capsaicin prevents the effects of the negative energy balance on desire to eat. PMID:24630935

  4. Global Energy and Water Balances in the Latest Reanalyses

    NASA Astrophysics Data System (ADS)

    Ahn, Joong-Bae; Kang, Suchul; Park, Hye-Jin

    2016-04-01

    The recently released Japanese 55-year Reanalysis (JRA-55) data are evaluated and compared with three other global reanalyses, namely Interim version of the next European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERRA-Interim), Modern Era Retrospective-Analysis for Research and Applications (MERRA) and Climate Forecast System Reanalysis (CFSR), in terms of global energy and water balances. All four reanalyses show an energy imbalance at TOA and surface. Especially, clouds in JRA-55 are optically weaker than those in the three other reanalyses, leading to excessive outgoing longwave radiation, which in turn causes negative net energy flux at TOA. Moreover, JRA-55 has a negative imbalance at surface and at TOA, which is attributed to systematic positive biases in latent heat flux over the ocean. As for the global water balance, all reanalyses present a similar spatial pattern of the difference between evaporation and precipitation (E-P). However, JRA-55 has a relatively strong negative (positive) E-P in the Intertropical Convergence Zone and South Pacific Convergence Zone (extratropical regions) due to overestimated precipitation (evaporation), in spite of the global net being close to zero. In time series analysis, especially in E-P, significant stepwise changes occur in MERRA, CFSR and ERA-Interim due to the changes occur in MERRA, CFRS and ERA-Interim due to the changes in the satellite observing system used in the data assimilation. Both MERRA and CFSR show a strong downward E-P shift in 1998, simultaneously with the start of the assimilation of AMSU-A sounding radiances. ERA-Interim exhibits an upward E-P shift in 1992 due to changes in observations from the SSM/I of new DMSP satellites. On the contrary, JRA-55 exhibits less trends and remains stable over time, which may be caused by newly available, homogenized observations and advances in data assimilation technique. Acknowledgements This work was funded by the Korea Meteorological

  5. Energy Balance during Taekwondo Practice in Elite Male Taekwondo Players

    PubMed Central

    Cho, Kang Ok; Garber, Carol Ewing; Lee, Sukho; Kim, Yeon Soo

    2013-01-01

    Background The goal of this study was to evaluate energy expenditure and dietary intake of nutrients during Taekwondo practice in elite Korean male Taekwondo players. Methods: Elite Korean male high school (high school player: HP; n = 59) and college players (college player: CP; n = 58) wore an accelerometer to measure energy expenditure and recorded their daily dietary intake for nutritional analysis over the course of five days. Results: Nutritional adequacy ratios for total energy (0.82), vitamin C (0.97), calcium (0.78), and folate (0.75) were below recommended levels for all players. When comparing daily nutrient intake and energy expenditure between HP and CP, the HP group had significantly higher total calorie intake (402.7 kcal, p < 0.001), calcium (126.3 mg, p = 0.018), phosphorus (198.0 mg, p = 0.002), iron (1.3 mg, p = 0.002), and vitamin B2 (0.4 mg, p < 0.001) than the CP group. Although there was no significant difference in the estimated energy requirement during Taekwondo practice, the total energy expenditure (151.2 kcal, p = 0.001), total activity counts (130,674 counts, p = 0.038) and energy expenditure during Taekwondo practice (257.7 kcal, p < 0.001) were significantly higher in the HP than in the CP. Conclusion: The results indicate that a sports nutrition program based on energy balance is necessary to achieve optimal health and performance in elite male Taekwondo players. PMID:26064838

  6. Enforcing elemental mass and energy balances for reduced order models

    SciTech Connect

    Ma, J.; Agarwal, K.; Sharma, P.; Lang, Y.; Zitney, S.; Gorton, I.; Agawal, D.; Miller, D.

    2012-01-01

    Development of economically feasible gasification and carbon capture, utilization and storage (CCUS) technologies requires a variety of software tools to optimize the designs of not only the key devices involved (e., g., gasifier, CO{sub 2} adsorber) but also the entire power generation system. High-fidelity models such as Computational Fluid Dynamics (CFD) models are capable of accurately simulating the detailed flow dynamics, heat transfer, and chemistry inside the key devices. However, the integration of CFD models within steady-state process simulators, and subsequent optimization of the integrated system, still presents significant challenges due to the scale differences in both time and length, as well the high computational cost. A reduced order model (ROM) generated from a high-fidelity model can serve as a bridge between the models of different scales. While high-fidelity models are built upon the principles of mass, momentum, and energy conservations, ROMs are usually developed based on regression-type equations and hence their predictions may violate the mass and energy conservation laws. A high-fidelity model may also have the mass and energy balance problem if it is not tightly converged. Conservations of mass and energy are important when a ROM is integrated to a flowsheet for the process simulation of the entire chemical or power generation system, especially when recycle streams are connected to the modeled device. As a part of the Carbon Capture Simulation Initiative (CCSI) project supported by the U.S. Department of Energy, we developed a software framework for generating ROMs from CFD simulations and integrating them with Process Modeling Environments (PMEs) for system-wide optimization. This paper presents a method to correct the results of a high-fidelity model or a ROM such that the elemental mass and energy are conserved perfectly. Correction factors for the flow rates of individual species in the product streams are solved using a

  7. Preliminary approach of the MELiSSA loop energy balance

    NASA Astrophysics Data System (ADS)

    Poulet, Lucie; Lamaze, Brigitte; Lebrun, Jean

    Long duration missions, such as the establishment of permanent bases on the lunar surface or the travel to Mars, require a huge amount of life support consumables (e.g. food, water and oxygen). Current rockets are at the moment unable to launch such a mass from Earth. Consequently Regenerative Life Support Systems are necessary to sustain long-term manned space mission to increase recycling rates and so reduce the launched mass. Thus the European and Canadian research has been concentrating on the MELiSSA (Micro-Ecological Life Support System Alternative) project over the last 20 years. MELiSSA is an Environmental Controlled Life Support System (ECLSS), i.e. a closed regenerative loop inspired of a lake ecosystem. Using light as a source of energy, MELiSSA's goal is the recovery of food, water and oxygen from CO2 and organic wastes, using microorganisms and higher plants. The architecture of a ECLSS depends widely on the mission scenario. To compare several ECLSS architectures and in order to be able to evaluate them, ESA is developing a multi criteria evaluation tool: ALISSE (Advanced LIfe Support System Evaluator). One of these criteria is the energy needed to operate the ECLSS. Unlike other criteria like the physical mass, the energy criterion has not been investigated yet and needs hence a detailed analysis. It will consequently be the focus of this study. The main objective of the work presented here is to develop a dynamic tool able to estimate the energy balance for several configurations of the MELiSSA loop. The first step consists in establishing the energy balance using concrete figures from the MELiSSA Pilot Plant (MPP). This facility located at the Universitat Autonoma de Barcelona (UAB) is aimed at the ground demonstration of the MELiSSA loop. The MELiSSA loop is structured on several subsystems; each of them is characterized by supplies, exhausts and process reactions. For the purpose of this study (i.e. a generic tool) the solver EES (Engineering

  8. Global energy and water balances in the latest reanalyses

    NASA Astrophysics Data System (ADS)

    Kang, Suchul; Ahn, Joong-Bae

    2015-11-01

    The recently released Japanese 55-year Reanalysis (JRA- 55) data are evaluated and compared with three other global reanalyses, namely Interim version of the next European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-Interim), Modern Era Retrospective-Analysis for Research and Applications (MERRA) and Climate Forecast System Reanalysis (CFSR), in terms of global energy and water balances. All four reanalyses show an energy imbalance at TOA and surface. Especially, clouds in JRA-55 are optically weaker than those in the three other reanalyses, leading to excessive outgoing longwave radiation, which in turn causes negative net energy flux at TOA. Moreover, JRA-55 has a negative imbalance at surface and at TOA, which is attributed to systematic positive biases in latent heat flux over the ocean. As for the global water balance, all reanalyses present a similar spatial pattern of the difference between evaporation and precipitation (E-P). However, JRA-55 has a relatively strong negative (positive) E-P in the Intertropical Convergence Zone and South Pacific Convergence Zone (extratropical regions) due to overestimated precipitation (evaporation), in spite of the global net being close to zero. In time series analysis, especially in E-P, significant stepwise changes occur in MERRA, CFSR and ERA-Interim due to the changes in the satellite observing system used in the data assimilation. Both MERRA and CFSR show a strong downward E-P shift in 1998, simultaneously with the start of the assimilation of AMSU-A sounding radiances. ERA-Interim exhibits an upward E-P shift in 1992 due to changes in observations from the SSM/I of new DMSP satellites. On the contrary, JRA-55 exhibits less trends and remains stable over time, which may be caused by newly available, homogenized observations and advances in data assimilation technique.

  9. A Satellite Based Study of Surface Energy Fluxes and Closing the Energy Balance

    NASA Astrophysics Data System (ADS)

    Didari, S.; Skoko-Dobryansky, S.; Norouzi, H.

    2014-12-01

    All agricultural, hydrological and biological processes are affected by the amount of available energy. Spatially distributed air temperature is one of the most important variables in various scientific fields. Although meteorological stations provide accurate data observations, their spatial coverage is limited and thus often insufficient for environmental modeling. Remote sensing provides the spatial data and it fills the spatial and temporal gaps left by the meteorological stations. In this study, the surface energy balance and Moderate Resolution Imaging Spectroradiometer (MODIS) products through the years 2003-2013 are used in order to estimate air temperature for New York City region and Fars Province region in south of Iran. Land surface temperature, evapotranspiration and surface reflectance data were obtained from MODIS, and by using the surface energy balance equation the air temperature is computed and analyzed. The amount of fluxes seasonally is investigated as one the most important and governing components of the energy balance.

  10. The global land and ocean mean energy balance

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Folini, Doris

    2016-04-01

    The energy balance over land and oceans governs a diversity of terrestrial and maritime processes and is the key determinant of climatic conditions in these areas. Despite its crucial role, climate models show significant differences in the individual components of the energy balance over both land and oceans, particularly at the surface. Here we combine a comprehensive set of radiation observations from GEBA and BSRN with 43 state-of-the-art climate models to infer best estimates for present day annual mean downward solar and thermal radiation averaged over land and ocean surfaces, together with their uncertainty ranges. Over land (including the polar ice sheets), where most direct observations are available to constrain the surface fluxes, we obtain 184 and 306 Wm-2 for solar and thermal downward radiation, respectively. Over oceans, with weaker observational constraints, corresponding estimates are around 185 and 356 Wm-2. These values closely agree, mostly within 3 Wm-2, with the respective quantities independently derived by a state-of-the-art reanalysis (ERA-Interim) and satellite-derived product (surface CERES EBAF). This remarkable consistency enhances confidence in the determined flux magnitudes, which so far stated large uncertainty sources in the energy budgets. The estimated downward solar radiation averaged over land and ocean surfaces is almost identical despite differences in the incoming solar flux at the Top-of-Atmosphere (TOA) around 20 Wm-2, indicative of an overall less transparent atmosphere over oceans than land. Considering additionally surface albedo and emissivity, we infer a surface absorbed solar and net thermal radiation of 136 and -66 Wm-2 over land, and 170 and -53 Wm-2 over oceans, respectively. The surface net radiation is thus estimated at 70 Wm-2 over land and 117 Wm-2 over oceans, which may impose additional constraints on the poorly known sensible and latent heat flux magnitudes. These are estimated here near 32 and 38 Wm-2 over

  11. p75 neurotrophin receptor regulates energy balance in obesity

    PubMed Central

    Baeza-Raja, Bernat; Sachs, Benjamin D.; Li, Pingping; Christian, Frank; Vagena, Eirini; Davalos, Dimitrios; Le Moan, Natacha; Ryu, Jae Kyu; Sikorski, Shoana L.; Chan, Justin P.; Scadeng, Miriam; Taylor, Susan S.; Houslay, Miles D.; Baillie, George S.; Saltiel, Alan R.; Olefsky, Jerrold M.; Akassoglou, Katerina

    2015-01-01

    Summary Obesity and metabolic syndrome reflect the dysregulation of molecular pathways that control energy homeostasis. Here we show that upon high-fat diet (HFD), the p75 neurotrophin receptor (p75NTR) controls energy expenditure in obese mice. Despite no changes in food intake, p75NTR-null mice were protected from HFD-induced obesity and remained lean due to increased energy expenditure, without developing insulin resistance or liver steatosis. p75NTR directly interacts with the catalytic subunit of protein kinase A (PKA) and regulates cAMP signaling in adipocytes, leading to decreased lipolysis and thermogenesis. Adipocyte-specific depletion of p75NTR or transplantation of p75NTR-null white adipose tissue (WAT) into wild-type mice fed a HFD protected against weight gain and insulin resistance. Our results reveal that signaling from p75NTR to cAMP/PKA regulates energy balance and suggest that non-neuronal functions of neurotrophin receptor signaling could be a new target for treating obesity and the metabolic syndrome. PMID:26748707

  12. An energy balance climate model with cloud feedbacks

    NASA Technical Reports Server (NTRS)

    Roads, J. O.; Vallis, G. K.

    1984-01-01

    The present two-level global climate model, which is based on the atmosphere-surface energy balance, includes physically based parameterizations for the exchange of heat and moisture across latitude belts and between the surface and the atmosphere, precipitation and cloud formation, and solar and IR radiation. The model field predictions obtained encompass surface and atmospheric temperature, precipitation, relative humidity, and cloudiness. In the model integrations presented, it is noted that cloudiness is generally constant with changing temperature at low latitudes. High altitude cloudiness increases with temperature, although the cloud feedback effect on the radiation field remains small because of compensating effects on thermal and solar radiation. The net global feedback by the cloud field is negative, but small.

  13. Geospatial and Contextual Approaches to Energy Balance and Health

    PubMed Central

    Berrigan, David; Hipp, J. Aaron; Hurvitz, Philip M.; James, Peter; Jankowska, Marta M.; Kerr, Jacqueline; Laden, Francine; Leonard, Tammy; McKinnon, Robin A.; Powell-Wiley, Tiffany M.; Tarlov, Elizabeth; Zenk, Shannon N.

    2016-01-01

    In the past 15 years, a major research enterprise has emerged that is aimed at understanding associations between geographic and contextual features of the environment (especially the built environment) and elements of human energy balance, including diet, weight, and physical activity. Here we highlight aspects of this research area with a particular focus on research and opportunities in the United States as an example. We address four main areas: 1) The importance of valid and comparable data concerning behavior across geographies, 2) The ongoing need to identify and explore new environmental variables, 3) The challenge of identifying the causally relevant context, and 4) The pressing need for stronger study designs and analytical methods. Additionally, we discuss existing sources of geo-referenced health data which might be exploited by interdisciplinary research teams, personnel challenges and some aspects of funding for geospatial research by the US National Institutes of Health in the past decade, including funding for international collaboration and training opportunities. PMID:27076868

  14. Energy Balance of Triathletes during an Ultra-Endurance Event

    PubMed Central

    Barrero, Anna; Erola, Pau; Bescós, Raúl

    2014-01-01

    The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit. PMID:25558906

  15. An energy balance simulation tool for TOMS-EP

    SciTech Connect

    Mackowski, M.J.; Martin, D.K.

    1996-12-31

    A computer analysis tool has been developed to perform energy balance simulations of a spacecraft power subsystem. The purpose of the tool is to predict the battery state-of-charge as a function of time for different mission scenarios, particularly during the first few orbits. The load profile (power use versus time) and the solar array power available for charging the battery were both time-varying functions that were different for each scenario. Therefore an analysis tool was needed that could easily make changes to the load profile and select different levels of solar array power. This was accomplished by developing a simple spreadsheet that defined the load profiles, which would then be imported into another spreadsheet that performed the energy balance calculations, including the adjustments to the solar array output. The development of these relatively simple spreadsheets replaced a laborious manual process of defining the load profiles which were then sued in a less sophisticated spreadsheet.The improved version also added a capability to include loads prior to satellite separation from the launch vehicle. A more elaborate simulation program had also been used in the past, but it was inconvenient to use and was not as precise as the new spreadsheet. In summary, the new tool made it easy to quickly develop and evaluate many different operational scenarios. This process has been used to evaluate responses to various failure modes and to develop contingency plans for the first few orbits of the Total Ozone Mapping Spectrometer--Earth Probe (TOMS-EP) mission.

  16. An observationally based energy balance for the Earth since 1950

    NASA Astrophysics Data System (ADS)

    Murphy, D. M.; Solomon, S.; Portmann, R. W.; Rosenlof, K. H.; Forster, P. M.; Wong, T.

    2009-09-01

    We examine the Earth's energy balance since 1950, identifying results that can be obtained without using global climate models. Important terms that can be constrained using only measurements and radiative transfer models are ocean heat content, radiative forcing by long-lived trace gases, and radiative forcing from volcanic eruptions. We explicitly consider the emission of energy by a warming Earth by using correlations between surface temperature and satellite radiant flux data and show that this term is already quite significant. About 20% of the integrated positive forcing by greenhouse gases and solar radiation since 1950 has been radiated to space. Only about 10% of the positive forcing (about 1/3 of the net forcing) has gone into heating the Earth, almost all into the oceans. About 20% of the positive forcing has been balanced by volcanic aerosols, and the remaining 50% is mainly attributable to tropospheric aerosols. After accounting for the measured terms, the residual forcing between 1970 and 2000 due to direct and indirect forcing by aerosols as well as semidirect forcing from greenhouse gases and any unknown mechanism can be estimated as -1.1 ± 0.4 W m-2 (1σ). This is consistent with the Intergovernmental Panel on Climate Change's best estimates but rules out very large negative forcings from aerosol indirect effects. Further, the data imply an increase from the 1950s to the 1980s followed by constant or slightly declining aerosol forcing into the 1990s, consistent with estimates of trends in global sulfate emissions. An apparent increase in residual forcing in the late 1990s is discussed.

  17. Energy balance and cold adaptation in the octopus Pareledone charcoti.

    PubMed

    Daly; Peck

    2000-03-15

    A complete energy balance equation is calculated for the Antarctic octopus Pareledone charcoti at 0 degrees C. Energy used in respiration, growth, and excretion of nitrogenous and faecal waste, was recorded along with the total consumption of energy through food, for three specimens of P. charcoti (live weights: 73, 51 and 29 g). Growth rates were very slow for cephalopods, with a mean daily increase in body weight of only 0.11%. Assimilation efficiencies were high, between 95.4 and 97.0%, which is consistent with previous work on octopods. The respiration rate in P. charcoti was low, with a mean of 2.45 mg O(2) h(-1) for a standard animal of 150 g wet mass at 0 degrees C. In the North Sea octopus Eledone cirrhosa, respiration rates of 9.79 mg O(2) h(-1) at 11.5 degrees C and 4.47 mg O(2) h(-1) at 4.5 degrees C for a standard animal of 150 g wet mass were recorded. Respiration rates between P. charcoti and E. cirrhosa were compared using a combined Q(10) value between P. charcoti at 0 degrees C and E. cirrhosa at 4.5 degrees C. This suggests that P. charcoti are respiring at a level predicted by E. cirrhosa rates at 4.5 and 11.5 degrees C extrapolated to 0 degrees C along the curve Q(10)=3, with no evidence of metabolic compensation for low temperature. PMID:10699210

  18. Energy balance for sustained spheromak plasmas in SSPX

    NASA Astrophysics Data System (ADS)

    Hill, D. N.; Auerbach, D.; Bulmer, R.; McLean, H.; Wood, R.; Woodruff, S.

    2001-10-01

    Formation of self-organized spheromak plasmas requires, at a minimum, that the input power exceed the loss power in order to increase magnetic field strength. Other factors, such as injector geometry or low-order MHD modes, are also thought to affect the formation process. In SSPX we measure both the input power at the coaxial source, and the loss power to the flux conserver (radiation and plasma conduction) to obtain the global power balance which we can relate to the field buildup. The radiation loss is determined by wide field-of-view bolometers, both time-integrated and time-resolved. Radiation losses are dominated by low-Z impurities and are typically less than 20energy input for clean discharges. We use edge magnetic probe measurements as input to the CORSICA code to determine the total stored magnetic energy and ohmic heating power, which then allows us to compute the energy confinement time from density and temperature profiles obtained by Thomson scattering. This work was performed under the auspices of US DOE by the University of California Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

  19. Confinement time and energy balance in the CTX spheromak

    SciTech Connect

    Barnes, C.W.; Henins, I.; Hoida, H.W.; Jarboe, T.R.

    1984-01-01

    The multipoint Thomson scattering diagnostic on CTX allows measurement of electron plasma pressure. The pressure correlates well with the poloidal flux function. Analysis using equilibrium models allows the (..beta..)/sub vol/ to be calculated from over 100 Thomson scattering profiles taken under standard conditions of spheromak operation where the plasma parameters vary widely within the discharge. The calculated tau/sub E/ increases with central core temperature and with density. The global magnetic energy decay time tau/sub B/2 is consistent with Spitzer-Harm resistivity, but with an anomaly factor of 2 to 4 which may decrease at small ratios of B/n. The n tau/sub E/ product reaches 4 x 10/sup 9/ s cm/sup -3/ during the hottest part of the discharge. A zero-dimensional energy balance code, which accurately includes all the major atomic physics processes and whose parameters have been constrained by comparision to experimental data, is used to identify the causes of energy loss that contribute to the observed confinement time. The most important power loss is that needed to replace the particles being lost and to maintain the constant density of the plateau.

  20. Energy balance and the composition of weight loss during prolonged space flight

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1982-01-01

    Integrated metabolic balance analysis, Skylab integrated metabolic balance analysis and computer simulation of fluid-electrolyte responses to zero-g, overall mission weight and tissue losses, energy balance, diet and exercise, continuous changes, electrolyte losses, caloric and exercise requirements, and body composition are discussed.

  1. Simulating drought impacts on energy balance in an Amazonian rainforest

    NASA Astrophysics Data System (ADS)

    Imbuzeiro, H. A.; Costa, M. H.; Galbraith, D.; Christoffersen, B. O.; Powell, T.; Harper, A. B.; Levine, N. M.; Rowland, L.; Moorcroft, P. R.; Benezoli, V. H.; Meir, P.; da Costa, A. C. L.; Brando, P. M.; Malhi, Y.; Saleska, S. R.; Williams, M. D.

    2014-12-01

    The studies of the interaction between vegetation and climate change in the Amazon Basin indicate that up to half of the region's forests may be displaced by savanna vegetation by the end of the century. Additional analyses suggest that complex interactions among land use, fire-frequency, and episodic drought are driving an even more rapid process of the forest impoverishment and displacement referred here as "savannization". But it is not clear whether surface/ecosystem models are suitable to analyze extreme events like a drought. Long-term simulations of throughfall exclusion experiments has provided unique insights into the energy dynamics of Amazonian rainforests during drought conditions. In this study, we evaluate how well six surface/ecosystem models quantify the energy dynamics from two Amazonian throughfall exclusion experiments. All models were run for the Tapajós and Caxiuanã sites with one control plot using normal precipitation (i.e. do not impose a drought) and then the drought manipulation was imposed for several drought treatments (10 to 90% rainfall exclusion). The sap flow, net radiation (Rn), sensible (H), latent (LE) and ground (G) heat flux are used to analyze if the models are able to capture the dynamics of water stress and what the implications for the energy dynamics are. With respect to the model validation, when we compare the sap flow observed and transpiration simulated, models are more accurate to simulate control plots than drought treatments (50% rainfall exclusion). The results show that the models overestimate the sap flow data during the drought conditions, but they were able to capture the changes in the main energy balance components for different drought treatments. The Rn and LE decreased and H increased with more intensity of drought. The models sensitivity analysis indicate that models are more sensitive to drought when rainfall is excluded for more than 60% and when this reduction occurs during the dry season.

  2. Modeling the water and energy balance of vegetated areas with snow accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to quantify soil–atmosphere water and energy exchange is important in understanding agricultural and natural ecosystems, as well as the earth’s climate. We developed a one-dimensional vertical model that calculates solar radiation, canopy energy balance, surface energy balance, snowpack ...

  3. Estimating energy balance fluxes above a boreal forest from radiometric temperature observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The great areal extent of boreal forests confers these ecosystems potential to impact on the global surface-atmosphere energy exchange. A modeling approach, based on a simplified two-source energy balance model, was proposed to estimate energy balance fluxes above boreal forests using thermal infrar...

  4. Natriuretic peptide control of energy balance and glucose homeostasis.

    PubMed

    Coué, Marine; Moro, Cedric

    2016-05-01

    Cardiac natriuretic peptides (NP) have recently emerged as metabolic hormones. Physiological stimulation of cardiac NP release as during exercise may contribute to increase fatty acid mobilization from adipose tissue and their oxidation by skeletal muscles. Clinical studies have shown that although very high plasma NP level characterizes cardiac dysfunction and heart failure, a consistently reduced plasma NP level is observed in metabolic diseases such as obesity and type 2 diabetes. A low circulating NP level also predicts the risk of new onset type 2 diabetes. It is unclear at this stage if the "natriuretic handicap" observed in obesity is causally associated with the incidence of type 2 diabetes. Recent work indicates that NP can activate a thermogenic program in brown and white fat, increase energy expenditure and inhibit food intake. Mouse studies also argue for a key role of NP in the regulation of energy balance and glucose homeostasis. This review will focus on recent human and mouse studies to highlight the metabolic roles of NP and their potential relevance in the context of obesity and type 2 diabetes. PMID:26037452

  5. Energy balance in the course of relativistic magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Semenov, V. S.; Tolstykh, Yu. V.; Dyadechkin, S. A.

    Magnetic reconnection plays an important role in space physics, for example, in Earth's magnetosphere, on the Sun, in the magnetospheres of magnetars, pulsars, black holes, etc. Reconnection starts with abrupt drop of plasma conductivity in a small part of a current sheet, so called, diffusion region. As a result electric field is generated and is transferred by relativistic MHD surface wave from the diffusion region to the current sheet which leads to decay of the disturbed part of the current sheet into a system of slow shocks. Plasma is highly accelerated and heated at the shock fronts forming outflow region with relativistic plasma jets and weak magnetic field (Semenov & Bernikov 1991). At some stage the reconnection process has to switch-off, then outflow regions must detach from the site where the electric field was initiated, and propagate along the current sheet as solitary waves (Tolstykh et al. 2005). The energy balance of relativistic reconnection is investigated in details. It is shown that magnetic and thermal energy from the inflow region is spent for acceleration and heating of the plasma in jets. It is interesting that the temperature of the plasma in the wake of the propagating outflow regions drops after each pulse of reconnection. This differ from usual explosion which heats the plasma behind the shock front (Tolstykh et al. 2007).

  6. Energy Balance Around Gas Injection into Oxygen Steelmaking

    NASA Astrophysics Data System (ADS)

    Sabah, Shabnam; Brooks, Geoffrey

    2016-02-01

    In the present work, a simplified approach of energy balance around gas injection into oxygen steelmaking has been carried out in a cold model. The aim is to provide an estimation of the amount of energy consumed by the different parts of the injection process such as dissipation, stirring of the bath, cavity formation, and splashing. Calculation of jet power used by different processes has been carried for various operating conditions and cavity modes ( i.e., splashing and penetrating). Calculations showed that dissipation and splashing are the dominant processes where most of the power of the jet is used, whereas cavity formation consumes the least amount. In the splashing mode, the percentage of total input power going into dissipation was about 59 to 63 pct, whereas it was found to be 2.6 to 50 pct in the penetrating mode. In splashing mode, about 30 pct power from the nozzle was used to create splash which is proved to be an efficient mode for droplet generation as less power is required to create droplets. At a certain lance height, the percentages of total input power used for splashing and dissipation were found equal. Below this lance height, all the cavities were found to be in penetrating mode. This simplified approach provides an improved understanding of the gas injection process and may be used for developing models of the injection process of steelmaking.

  7. DET/MPS - The GSFC Energy Balance Programs

    NASA Technical Reports Server (NTRS)

    Jagielski, J. M.

    1994-01-01

    Direct Energy Transfer (DET) and MultiMission Spacecraft Modular Power System (MPS) computer programs perform mathematical modeling and simulation to aid in design and analysis of DET and MPS spacecraft power system performance in order to determine energy balance of subsystem. DET spacecraft power system feeds output of solar photovoltaic array and nickel cadmium batteries directly to spacecraft bus. MPS system, Standard Power Regulator Unit (SPRU) utilized to operate array at array's peak power point. DET and MPS perform minute-by-minute simulation of performance of power system. Results of simulation focus mainly on output of solar array and characteristics of batteries. Both packages limited in terms of orbital mechanics, they have sufficient capability to calculate data on eclipses and performance of arrays for circular or near-circular orbits. DET and MPS written in FORTRAN-77 with some VAX FORTRAN-type extensions. Both available in three versions: GSC-13374, for DEC VAX-series computers running VMS. GSC-13443, for UNIX-based computers. GSC-13444, for Apple Macintosh computers.

  8. Reciprocal Compensation to Changes in Dietary Intake and Energy Expenditure within the Concept of Energy Balance.

    PubMed

    Drenowatz, Clemens

    2015-09-01

    An imbalance between energy intake and energy expenditure is the primary etiology for excess weight gain. Increased energy expenditure via exercise and energy restriction via diet are commonly used approaches to induce weight loss. Such behavioral interventions, however, have generally resulted in a smaller than expected weight loss, which in part has been attributed to compensatory adaptations in other components contributing to energy balance. Current research points to a loose coupling between energy intake and energy expenditure on a daily basis, and evidence for long-term adaptations has been inconsistent. The lack of conclusive evidence on compensatory adaptations in response to alterations in energy balance can be attributed to differences in intervention type and study population. Physical activity (PA) levels may be reduced in response to aerobic exercise but not in response to resistance exercise. Furthermore, athletic and lean adults have been shown to increase their energy intake in response to exercise, whereas no such response was observed in obese adults. There is also evidence that caloric restriction is associated with a decline in PA. Generally, humans seem to be better equipped to defend against weight loss than avoid weight gain, but results also show a large individual variability. Therefore, individual differences rather than group means should be explored to identify specific characteristics of "compensators" and "noncompensators." This review emphasizes the need for more research with simultaneous measurements of all major components contributing to energy balance to enhance the understanding of the regulation of energy balance, which is crucial to address the current obesity epidemic. PMID:26374181

  9. ANALYSIS OF WATER AND ENERGY FLUXES USING SATELLITE, ENERGY BALANCE MODELING AND OBSERVATIONS (Invited)

    NASA Astrophysics Data System (ADS)

    Irmak, A.

    2009-12-01

    Surface energy fluxes, including net radiation (Rn), sensible heat (H), latent heat (LE), and soil heat flux (G) are critical in surface energy balance of any terrain or landscapes. Estimation or measurement of these energy fluxes is important for completing the water balance in terrestrial ecosystems, and therefore accurately predicting the effects of global climate and land use change. The objectives of this study were to (1) use METRICtm (Mapping Evapotranspiration at high Resolution using Internalized Calibration) model for estimating land surface energy fluxes in Nebraska (NE) by utilizing satellite remote sensing data, (2) identify model bias in energy balance components compared with measurements from Bowen Ratio Energy Balance System (BREBS) in a subsurface drip-irrigated maize field in South-central Nebraska, and (3) understand the partitioning of available energy into latent heat for corn and soybean cropping systems at large scale. A total of 15 Landsat images were processed to estimate instantaneous surface energy fluxes at Landsat overpasses with METRIC model. Results showed that the model predictions of the surface energy fluxes and daily evapotranspiration were correlated well with the BREBS measurements. There is a need, however, to test the performance of the model with in-situ observations in other locations with different dataset before utilizing it for crucial water regulatory and policy decisions. The METRICtm approach illustrated how an ‘off-the-shelf’ model can be applied operationally over a significant time period and how that model behaves. The findings makes considerable contribution to our understanding of estimating land surface energy fluxes using remote sensing approach and experimentally describes the operational characteristics of METRICtm and presents its limitations.

  10. Gut microbiota and energy balance: role in obesity.

    PubMed

    Blaut, Michael

    2015-08-01

    The microbial community populating the human digestive tract has been linked to the development of obesity, diabetes and liver diseases. Proposed mechanisms on how the gut microbiota could contribute to obesity and metabolic diseases include: (1) improved energy extraction from diet by the conversion of dietary fibre to SCFA; (2) increased intestinal permeability for bacterial lipopolysaccharides (LPS) in response to the consumption of high-fat diets resulting in an elevated systemic LPS level and low-grade inflammation. Animal studies indicate differences in the physiologic effects of fermentable and non-fermentable dietary fibres as well as differences in long- and short-term effects of fermentable dietary fibre. The human intestinal microbiome is enriched in genes involved in the degradation of indigestible polysaccharides. The extent to which dietary fibres are fermented and in which molar ratio SCFA are formed depends on their physicochemical properties and on the individual microbiome. Acetate and propionate play an important role in lipid and glucose metabolism. Acetate serves as a substrate for de novo lipogenesis in liver, whereas propionate can be utilised for gluconeogenesis. The conversion of fermentable dietary fibre to SCFA provides additional energy to the host which could promote obesity. However, epidemiologic studies indicate that diets rich in fibre rather prevent than promote obesity development. This may be due to the fact that SCFA are also ligands of free fatty acid receptors (FFAR). Activation of FFAR leads to an increased expression and secretion of enteroendocrine hormones such as glucagon-like-peptide 1 or peptide YY which cause satiety. In conclusion, the role of SCFA in host energy balance needs to be re-evaluated. PMID:25518735

  11. The causal role of breakfast in energy balance and health: a randomized controlled trial in lean adults1234

    PubMed Central

    Betts, James A; Richardson, Judith D; Chowdhury, Enhad A; Holman, Geoffrey D; Tsintzas, Kostas; Thompson, Dylan

    2014-01-01

    Background: Popular beliefs that breakfast is the most important meal of the day are grounded in cross-sectional observations that link breakfast to health, the causal nature of which remains to be explored under real-life conditions. Objective: The aim was to conduct a randomized controlled trial examining causal links between breakfast habits and all components of energy balance in free-living humans. Design: The Bath Breakfast Project is a randomized controlled trial with repeated-measures at baseline and follow-up in a cohort in southwest England aged 21–60 y with dual-energy X-ray absorptiometry–derived fat mass indexes ≤11 kg/m2 in women (n = 21) and ≤7.5 kg/m2 in men (n = 12). Components of energy balance (resting metabolic rate, physical activity thermogenesis, energy intake) and 24-h glycemic responses were measured under free-living conditions with random allocation to daily breakfast (≥700 kcal before 1100) or extended fasting (0 kcal until 1200) for 6 wk, with baseline and follow-up measures of health markers (eg, hematology/biopsies). Results: Contrary to popular belief, there was no metabolic adaptation to breakfast (eg, resting metabolic rate stable within 11 kcal/d), with limited subsequent suppression of appetite (energy intake remained 539 kcal/d greater than after fasting; 95% CI: 157, 920 kcal/d). Rather, physical activity thermogenesis was markedly higher with breakfast than with fasting (442 kcal/d; 95% CI: 34, 851 kcal/d). Body mass and adiposity did not differ between treatments at baseline or follow-up and neither did adipose tissue glucose uptake or systemic indexes of cardiovascular health. Continuously measured glycemia was more variable during the afternoon and evening with fasting than with breakfast by the final week of the intervention (CV: 3.9%; 95% CI: 0.1%, 7.8%). Conclusions: Daily breakfast is causally linked to higher physical activity thermogenesis in lean adults, with greater overall dietary energy intake but no

  12. The causal role of breakfast in energy balance and health: a randomized controlled trial in obese adults12

    PubMed Central

    Chowdhury, Enhad A; Richardson, Judith D; Holman, Geoffrey D; Tsintzas, Kostas; Thompson, Dylan; Betts, James A

    2016-01-01

    Background: The causal nature of associations between breakfast and health remain unclear in obese individuals. Objective: We sought to conduct a randomized controlled trial to examine causal links between breakfast habits and components of energy balance in free-living obese humans. Design: The Bath Breakfast Project is a randomized controlled trial with repeated measures at baseline and follow-up among a cohort in South West England aged 21–60 y with dual-energy X-ray absorptiometry–derived fat mass indexes of ≥13 kg/m2 for women (n = 15) and ≥9 kg/m2 for men (n = 8). Components of energy balance (resting metabolic rate, physical activity thermogenesis, diet-induced thermogenesis, and energy intake) were measured under free-living conditions with random allocation to daily breakfast (≥700 kcal before 1100) or extended fasting (0 kcal until 1200) for 6 wk, with baseline and follow-up measures of health markers (e.g., hematology/adipose biopsies). Results: Breakfast resulted in greater physical activity thermogenesis during the morning than when fasting during that period (difference: 188 kcal/d; 95% CI: 40, 335) but without any consistent effect on 24-h physical activity thermogenesis (difference: 272 kcal/d; 95% CI: −254, 798). Energy intake was not significantly greater with breakfast than fasting (difference: 338 kcal/d; 95% CI: −313, 988). Body mass increased across both groups over time but with no treatment effects on body composition or any change in resting metabolic rate (stable within 8 kcal/d). Metabolic/cardiovascular health also did not respond to treatments, except for a reduced insulinemic response to an oral-glucose-tolerance test over time with daily breakfast relative to an increase with daily fasting (P = 0.05). Conclusions: In obese adults, daily breakfast leads to greater physical activity during the morning, whereas morning fasting results in partial dietary compensation (i.e., greater energy intake) later in the day. There were

  13. Analysis of the energy balance in lung cancer patients.

    PubMed

    Staal-van den Brekel, A J; Schols, A M; ten Velde, G P; Buurman, W A; Wouters, E F

    1994-12-15

    Previous studies have shown that an elevated resting energy expenditure (REE) frequently occurs in lung cancer patients. The aim of the present study was to assess the balance between REE and dietary intake and to analyze the contributing factors of elevated REE in newly detected lung cancer patients. One hundred newly detected lung cancer patients were evaluated. Measured values of REE were adjusted for the values predicted by the Harris-Benedict formula and for fat-free mass assessed by the bioelectrical impedance method. Dietary intake was measured using a dietary history. A substantial number of patients (30%) had a weight loss of 10% or more from their preillness stable weight. An elevated REE was found in 74% of the patients. Stratification by tumor localization revealed that patients with a central tumor had a significantly higher REE [121 +/- 13% (SD) versus 110 +/- 10% of predicted, P < 0.001] and significantly higher level of C-reactive protein (35 +/- 35 mg/liter versus 16 +/- 26 mg/liter, P = 0.006) compared with patients with a peripheral tumor. Dietary intake was significantly lower in the weight-losing group (1872 +/- 542 kcal/day versus 2169 +/- 782 kcal/day, P < 0.05) compared with the weight-stable group. We conclude that both elevated REE and decreased dietary intake contribute to weight loss in lung cancer patients. Tumor localization and inflammation were found to be contributing factors to the elevated REE. PMID:7987838

  14. Amylin Modulates the Mesolimbic Dopamine System to Control Energy Balance

    PubMed Central

    Mietlicki-Baase, Elizabeth G; Reiner, David J; Cone, Jackson J; Olivos, Diana R; McGrath, Lauren E; Zimmer, Derek J; Roitman, Mitchell F; Hayes, Matthew R

    2015-01-01

    Amylin acts in the CNS to reduce feeding and body weight. Recently, the ventral tegmental area (VTA), a mesolimbic nucleus important for food intake and reward, was identified as a site-of-action mediating the anorectic effects of amylin. However, the long-term physiological relevance and mechanisms mediating the intake-suppressive effects of VTA amylin receptor (AmyR) activation are unknown. Data show that the core component of the AmyR, the calcitonin receptor (CTR), is expressed on VTA dopamine (DA) neurons and that activation of VTA AmyRs reduces phasic DA in the nucleus accumbens core (NAcC). Suppression in NAcC DA mediates VTA amylin-induced hypophagia, as combined NAcC D1/D2 receptor agonists block the intake-suppressive effects of VTA AmyR activation. Knockdown of VTA CTR via adeno-associated virus short hairpin RNA resulted in hyperphagia and exacerbated body weight gain in rats maintained on high-fat diet. Collectively, these findings show that VTA AmyR signaling controls energy balance by modulating mesolimbic DA signaling. PMID:25035079

  15. Energy balance affected by electrolyte recirculation and operating modes in microbial fuel cells.

    PubMed

    Jacobson, Kyle S; Kelly, Patrick T; He, Zhen

    2015-03-01

    Energy recovery and consumption in a microbial fuel cell (MFC) can be significantly affected by the operating conditions. This study investigated the effects of electrolyte recirculation and operation mode (continuous vs sequence batch reactor) on the energy balance in a tubular MFC. It was found that decreasing the anolyte recirculation also decreased the energy recovery. Because of the open environment of the cathode electrode, the catholyte recirculation consumed 10 to 50 times more energy than the anolyte recirculation, and resulted in negative energy balances despite the reduction of the anolyte recirculation. Reducing the catholyte recirculation to 20% led to a positive energy balance of 0.0288 kWh m(-3). The MFC operated as a sequence batch reactor generated less energy and had a lower energy balance than the one with continuous operation. Those results encourage the further development of MFC technology to achieve neutral or even positive energy output. PMID:25842536

  16. Careful Measurements and Energy Balance Closure - The Case of Soil Heat Flux

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An area of persistent concern in micrometeorological measurements is the failure to close the energy balance at surface flux stations. While most attention has focused on corrections associated with the eddy fluxes, none of the energy balance terms are measured without error. The flux plate method i...

  17. Increased Protein Maintains Nitrogen Balance during Exercise-Induced Energy Deficit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PURPOSE: This study examined how a high-protein diet affected nitrogen balance and protein turnover during an exercise-induced energy deficit. METHODS: Twenty-two men completed a 4-d (D1-4) baseline period (BL) of an energy balance diet while maintaining usual physical activity level, followed by 7 ...

  18. Surface Energy Balance System for Estimating Daily Evapotranspiration Rates in the Texas High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous energy balance (EB) algorithms have been developed to use remote sensing data for mapping evapotranspiration (ET) on a regional basis. Adopting any single or a combination of these models for an operational ET remote sensing program requires thorough evaluation. The Surface Energy Balance S...

  19. TILLAGE AND ROTATION EFFECTS ON ENERGY BALANCES IN CORN AND SOYBEAN SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited information is available regarding the effect of common management practices on the energy balance of corn and soybean cropping systems. Energy balances were calculated for continuous corn, continuous soybean, and corn-soybean rotations under six tillage treatments that included no-tillage, ...

  20. Symposium Papers-Progress in Radiation and Energy Balance Measurement Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On November 2, 2004, an all-day symposium entitled “Progress in Radiation and Energy Balance Measurement Systems” was convened at the ASA-CSSA-SSSA annual meetings in Seattle, WA. Interest in the measurement of radiation and energy balance components at soil and plant canopy surfaces has seen a res...

  1. Socioecological correlates of energy balance using urinary C-peptide measurements in wild female mountain gorillas.

    PubMed

    Grueter, Cyril C; Deschner, Tobias; Behringer, Verena; Fawcett, Katie; Robbins, Martha M

    2014-03-29

    Maintaining a balanced energy budget is important for survival and reproduction, but measuring energy balance in wild animals has been fraught with difficulties. Female mountain gorillas are interesting subjects to examine environmental correlates of energy balance because their diet is primarily herbaceous vegetation, their food supply shows little seasonal variation and is abundant, yet they live in cooler, high-altitude habitats that may bring about energetic challenges. Social and reproductive parameters may also influence energy balance. Urinary C-peptide (UCP) has emerged as a valuable non-invasive biomarker of energy balance in primates. Here we use this method to investigate factors influencing energy balance in mountain gorillas of the Virunga Volcanoes, Rwanda. We examined a range of socioecological variables on energy balance in adult females in three groups monitored by the Karisoke Research Center over nine months. Three variables had significant effects on UCP levels: habitat (highest levels in the bamboo zone), season (highest levels in November during peak of the bamboo shoot availability) and day time (gradually increasing from early morning to early afternoon). There was no significant effect of reproductive state and dominance rank. Our study indicates that even in species that inhabit an area with a seemingly steady food supply, ecological variability can have pronounced effects on female energy balance. PMID:24472322

  2. Demographic, Dietary, and Urinary Factors and 24-h Urinary Calcium Excretion

    PubMed Central

    Curhan, Gary C.

    2009-01-01

    Background and objectives: Higher urinary calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and urinary factors and 24-h urinary calcium. Design, setting, participants, & measurements: Cross-sectional studies were conducted of 2201 stone formers (SF) and 1167 nonstone formers (NSF) in the Health Professionals Follow-up Study (men) and Nurses' Health Studies I and II (older and younger women). Results: Median urinary calcium was 182 mg/d in men, 182 mg/d in older women, and 192 mg/d in younger women. Compared with NSF, urinary calcium as a fraction of calcium intake was 33 to 38% higher in SF (P values ≤0.01). In regression analyses, participants were combined because associations with urinary calcium were similar in each cohort and in SF and NSF. After multivariate adjustment, participants in the highest quartile of calcium intake excreted 18 mg/d more urinary calcium than those in the lowest (P trend =0.01). Caffeine and family history of nephrolithiasis were positively associated, whereas urinary potassium, thiazides, gout, and age were inversely associated, with urinary calcium. After multivariate adjustment, participants in the highest quartiles of urinary magnesium, sodium, sulfate, citrate, phosphorus, and volume excreted 71 mg/d, 37 mg/d, 44 mg/d, 61 mg/d, 37 mg/d, and 24 mg/d more urinary calcium, respectively, than participants in the lowest (P values trend ≤0.01). Conclusions: Intestinal calcium absorption and/or negative calcium balance is greater in SF than NSF. Higher calcium intakes at levels typically observed in free-living individuals are associated with only small increases in urinary calcium. PMID:19820135

  3. Association of left ventricular diastolic dysfunction with 24-h aortic ambulatory blood pressure: the SAFAR study.

    PubMed

    Zhang, Y; Kollias, G; Argyris, A A; Papaioannou, T G; Tountas, C; Konstantonis, G D; Achimastos, A; Blacher, J; Safar, M E; Sfikakis, P P; Protogerou, A D

    2015-07-01

    Aortic blood pressure (BP) and 24-h ambulatory BP are both better associated with target organ damage than office brachial BP. However, it remains unclear whether a combination of these two techniques would be the optimal methodology to evaluate patients' BP in terms of left ventricular diastolic dysfunction (LVDD) prevention. In 230 participants, office brachial and aortic BPs were measured by a validated BP monitor and a tonometry-based device, respectively. 24-h ambulatory brachial and aortic BPs were measured by a validated ambulatory BP monitor (Mobil-O-Graph, Germany). Systematic assessment of patients' LVDD was performed. After adjustment for age, gender, hypertension and antihypertensive treatment, septum and lateral E/Ea were significantly associated with office aortic systolic BP (SBP) and pulse pressure (PP) and 24-h brachial and aortic SBP and PP (P ⩽ 0.04), but not with office brachial BP (P ⩾ 0.09). Similarly, 1 standard deviation in SBP was significantly associated with 97.8 ± 20.9, 86.4 ± 22.9, 74.1 ± 23.3 and 51.3 ± 22.6 in septum E/Ea and 68.6 ± 2 0.1, 54.2 ± 21.9, 37.9 ± 22.4 and 23.1 ± 21.4 in lateral E/Ea, for office and 24-h aortic and brachial SBP, respectively. In qualitative analysis, except for office brachial BP, office aortic and 24-h brachial and aortic BPs were all significantly associated with LVDD (P ⩽ 0.03), with the highest odds ratio in 24-h aortic SBP. Furthermore, aortic BP, no matter in the office or 24-h ambulatory setting, showed the largest area under receiver operating characteristic curves (P ⩽ 0.02). In conclusion, 24-h aortic BP is superior to other BPs in the association with LVDD. PMID:25391758

  4. Energy and CO2 balance of maize and grass as energy crops for anaerobic digestion.

    PubMed

    Gerin, Patrick A; Vliegen, François; Jossart, Jean-Marc

    2008-05-01

    Energy crops can be used to feed anaerobic digesters and produce renewable energy. However, sustainability of this option requires that it contributes to a net production of renewable energy and a net reduction of fossil CO2 emission. In this paper, the net balance of CO2 emission and renewable energy production is assessed for maize and grass energy crops produced in several agricultural systems relevant for Southern Belgium and surrounding areas. The calculated net energy yields are 8-25 (maize) and 7.4-15.5 (grass) MWh of renewable CH4 per MWh of fossil energy invested, depending on the agricultural option considered. After conversion to electricity, the specific CO2 emissions range from 31 to 104 kg(CO2)MWhelectricity(-1), depending on the case considered. This corresponds to a significant reduction in CO2 emissions compared to the current reference gas-steam turbine technology which produces 456 kg(CO2)MWhelectricity(-1). PMID:17574409

  5. Comparative analysis of net energy balance for satellite power systems (SPS) and other energy systems

    SciTech Connect

    Cirillo, R.R.; Cho, B.S.; Monarch, M.R.; Levine, E.P.

    1980-04-01

    The net energy balance of seven electric energy systems is assessed: two coal-based, one nuclear, two terrestrial solar, and two solar power satellites, with principal emphasis on the latter two systems. Solar energy systems require much less operating energy per unit of electrical output. However, on the basis of the analysis used here, coal and nuclear systems are two to five times more efficient at extracting useful energy from the primary resource base than are the solar energy systems. The payback period for all systems is less than 1.5 years, except for the terrestrial photovoltaic (19.8 yr) and the solar power satellite system (6.4 yr), both of which rely on energy-intensive silicon cells.

  6. Trends in research on energy balance supported by the National Cancer Institute.

    PubMed

    Ballard-Barbash, Rachel; Siddiqi, Sameer M; Berrigan, David A; Ross, Sharon A; Nebeling, Linda C; Dowling, Emily C

    2013-04-01

    Over the past decade, the body of research linking energy balance to the incidence, development, progression, and treatment of cancer has grown substantially. No prior NIH portfolio analyses have focused on energy balance within one institute. This portfolio analysis describes the growth of National Cancer Institute (NCI) grant research on energy balance-related conditions and behaviors from 2004 to 2010 following the release of an NCI research priority statement in 2003 on energy balance and cancer-related research. Energy balance grants from fiscal years (FY) 2004 to 2010 were identified using multiple search terms and analyzed between calendar years 2008 and 2010. Study characteristics related to cancer site, design, population, and energy balance area (physical activity, diet, and weight) were abstracted. From FY2004 to FY2010, the NCI awarded 269 energy balance-relevant grants totaling $518 million. In FY2010, 4.2% of NCI's total research project grants budget was allocated to energy balance research, compared to 2.1% in FY2004. The NCI more than doubled support for investigator-initiated research project grants (R01) and increased support for cooperative agreement (U01, U54) and exploratory research (R21) grants. In the portfolio, research examining energy balance areas in combination accounted for 41.6%, and observational and interventional studies were equally represented (38.3% and 37.2%, respectively). Breast cancer was the most commonly studied cancer. Inclusion of minorities rose, and funding specific to cancer survivors more than doubled. From FY2004 to FY2010, NCI's investment in energy balance and related health behavior research showed growth in funding and diversity of mechanisms, topics, and disciplines-growth that reflects new directions in this field. PMID:23498109

  7. Deficiency of PTP1B in POMC neurons leads to alterations in energy balance and homeostatic response to cold exposure

    PubMed Central

    De Jonghe, Bart C.; Hayes, Matthew R.; Banno, Ryoichi; Skibicka, Karolina P.; Zimmer, Derek J.; Bowen, Kerisha A.; Leichner, Theresa M.; Alhadeff, Amber L.; Kanoski, Scott E.; Cyr, Nicole E.; Nillni, Eduardo A.; Grill, Harvey J.

    2011-01-01

    The adipose tissue-derived hormone leptin regulates energy balance through catabolic effects on central circuits, including proopiomelanocortin (POMC) neurons. Leptin activation of POMC neurons increases thermogenesis and locomotor activity. Protein tyrosine phosphatase 1B (PTP1B) is an important negative regulator of leptin signaling. POMC neuron-specific deletion of PTP1B in mice results in reduced high-fat diet-induced body weight and adiposity gain due to increased energy expenditure and greater leptin sensitivity. Mice lacking the leptin gene (ob/ob mice) are hypothermic and cold intolerant, whereas leptin delivery to ob/ob mice induces thermogenesis via increased sympathetic activity to brown adipose tissue (BAT). Here, we examined whether POMC PTP1B mediates the thermoregulatory response of CNS leptin signaling by evaluating food intake, body weight, core temperature (TC), and spontaneous physical activity (SPA) in response to either exogenous leptin or 4-day cold exposure (4°C) in male POMC-Ptp1b-deficient mice compared with wild-type controls. POMC-Ptp1b−/− mice were hypersensitive to leptin-induced food intake and body weight suppression compared with wild types, yet they displayed similar leptin-induced increases in TC. Interestingly, POMC-Ptp1b−/− mice had increased BAT weight and elevated plasma triiodothyronine (T3) levels in response to a 4-day cold challenge, as well as reduced SPA 24 h after cold exposure, relative to controls. These data show that PTP1B in POMC neurons plays a role in short-term cold-induced reduction of SPA and may influence cold-induced thermogenesis via enhanced activation of the thyroid axis. PMID:21406615

  8. Parallel assessment of nutrition and activity in athletes: validation against doubly labelled water, 24-h urea excretion, and indirect calorimetry.

    PubMed

    Koehler, Karsten; Braun, Hans; De Marees, Markus; Fusch, Gerhard; Fusch, Christoph; Mester, Joachim; Schaenzer, Wilhelm

    2010-11-01

    The assessment of nutrition and activity in athletes requires accurate and precise methods. The aim of this study was to validate a protocol for parallel assessment of diet and exercise against doubly labelled water, 24-h urea excretion, and respiratory gas exchange. The participants were 14 male triathletes under normal training conditions. Energy intake and doubly labelled water were weakly associated with each other (r = 0.69, standard error of estimate [SEE] = 304 kcal x day(-1)). Protein intake was strongly correlated with 24-h urea (r = 0.89) but showed considerable individual variation (SEE = 0.34 g kg(-1) x day(-1)). Total energy expenditure based on recorded activities was highly correlated with doubly labelled water (r = 0.95, SEE = 195 kcal x day(-1)) but was proportionally biased. During running and cycling, estimated exercise energy expenditure was highly correlated with gas exchange (running: r = 0.89, SEE = 1.6 kcal x min(-1); cycling: r = 0.95, SEE = 1.4 kcal x min(-1)). High exercise energy expenditure was slightly underestimated during running. For nutrition data, variations appear too large for precise measurements in individual athletes, which is a common problem of dietary assessment methods. Despite the high correlations of total energy expenditure and exercise energy expenditure with reference methods, a correction for systematic errors is necessary for the valid estimation of energetic requirements in individual athletes. PMID:20967672

  9. [Energy requirement and nitrogen balance with a new fully balanced formula diet].

    PubMed

    Matzkies, F; Dorguth, B

    1981-06-11

    Eight healthy men received a formula diet over a period of 12 days. The acceptance of the diet was good. Gastroenterological side-effects were rarely noticed. Stool frequency was 0.5/day. To keep weight constant a caloric need of 24 +/- 3 cal/kg/BW was necessary. The nitrogen balance was regulated by feeding 59 g protein, 53 g fat and 216 g carbohydrate. The average intake of nitrogen amounted to 8.9 +/- 1.7 g/day. A daily nitrogen loss of 6.96 +/- 1.87 g/day was noticed. PMID:7262767

  10. An Intercomparison of the Surface Energy Balance Algorithm for Land (SEBAL) and the Two-Source Energy Balance (TSEB) Modeling Schemes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An intercomparison of output from two models estimating spatially distributed surface energy fluxes from remotely sensed imagery is conducted. A major difference between the two models is whether the soil and vegetation components of the scene are treated separately (Two-Source Energy Balance; TSEB ...

  11. Self-balancing dynamic scheduling of electrical energy for energy-intensive enterprises

    NASA Astrophysics Data System (ADS)

    Gao, Yunlong; Gao, Feng; Zhai, Qiaozhu; Guan, Xiaohong

    2013-06-01

    Balancing production and consumption with self-generation capacity in energy-intensive enterprises has huge economic and environmental benefits. However, balancing production and consumption with self-generation capacity is a challenging task since the energy production and consumption must be balanced in real time with the criteria specified by power grid. In this article, a mathematical model for minimising the production cost with exactly realisable energy delivery schedule is formulated. And a dynamic programming (DP)-based self-balancing dynamic scheduling algorithm is developed to obtain the complete solution set for such a multiple optimal solutions problem. For each stage, a set of conditions are established to determine whether a feasible control trajectory exists. The state space under these conditions is partitioned into subsets and each subset is viewed as an aggregate state, the cost-to-go function is then expressed as a function of initial and terminal generation levels of each stage and is proved to be a staircase function with finite steps. This avoids the calculation of the cost-to-go of every state to resolve the issue of dimensionality in DP algorithm. In the backward sweep process of the algorithm, an optimal policy is determined to maximise the realisability of energy delivery schedule across the entire time horizon. And then in the forward sweep process, the feasible region of the optimal policy with the initial and terminal state at each stage is identified. Different feasible control trajectories can be identified based on the region; therefore, optimising for the feasible control trajectory is performed based on the region with economic and reliability objectives taken into account.

  12. Combined solar thermal and photovoltaic power plants - An approach to 24h solar electricity?

    NASA Astrophysics Data System (ADS)

    Platzer, Werner J.

    2016-05-01

    Solar thermal power plants have the advantage of being able to provide dispatchable renewable electricity even when the sun is not shining. Using thermal energy strorage (TES) they may increase the capacity factor (CF) considerably. However in order to increase the operating hours one has to increase both, thermal storage capacity and solar field size, because the additional solar field is needed to charge the storage. This increases investment cost, although levelised electricity cost (LEC) may decrease due to the higher generation. Photovoltaics as a fluctuating source on the other side has arrived at very low generation costs well below 10 ct/kWh even for Central Europe. Aiming at a capacity factor above 70% and at producing dispatchable power it is shown that by a suitable combination of CSP and PV we can arrive at lower costs than by increasing storage and solar field size in CSP plants alone. Although a complete baseload power plant with more than 90% full load hours may not be the most economic choice, power plants approaching a full 24h service in most days of the year seem to be possible at reasonably low tariffs.

  13. An Enhanced Energy Balanced Data Transmission Protocol for Underwater Acoustic Sensor Networks.

    PubMed

    Javaid, Nadeem; Shah, Mehreen; Ahmad, Ashfaq; Imran, Muhammad; Khan, Majid Iqbal; Vasilakos, Athanasios V

    2016-01-01

    This paper presents two new energy balanced routing protocols for Underwater Acoustic Sensor Networks (UASNs); Efficient and Balanced Energy consumption Technique (EBET) and Enhanced EBET (EEBET). The first proposed protocol avoids direct transmission over long distance to save sufficient amount of energy consumed in the routing process. The second protocol overcomes the deficiencies in both Balanced Transmission Mechanism (BTM) and EBET techniques. EBET selects relay node on the basis of optimal distance threshold which leads to network lifetime prolongation. The initial energy of each sensor node is divided into energy levels for balanced energy consumption. Selection of high energy level node within transmission range avoids long distance direct data transmission. The EEBET incorporates depth threshold to minimize the number of hops between source node and sink while eradicating backward data transmissions. The EBET technique balances energy consumption within successive ring sectors, while, EEBET balances energy consumption of the entire network. In EEBET, optimum number of energy levels are also calculated to further enhance the network lifetime. Effectiveness of the proposed schemes is validated through simulations where these are compared with two existing routing protocols in terms of network lifetime, transmission loss, and throughput. The simulations are conducted under different network radii and varied number of nodes. PMID:27070605

  14. An Enhanced Energy Balanced Data Transmission Protocol for Underwater Acoustic Sensor Networks

    PubMed Central

    Javaid, Nadeem; Shah, Mehreen; Ahmad, Ashfaq; Imran, Muhammad; Khan, Majid Iqbal; Vasilakos, Athanasios V.

    2016-01-01

    This paper presents two new energy balanced routing protocols for Underwater Acoustic Sensor Networks (UASNs); Efficient and Balanced Energy consumption Technique (EBET) and Enhanced EBET (EEBET). The first proposed protocol avoids direct transmission over long distance to save sufficient amount of energy consumed in the routing process. The second protocol overcomes the deficiencies in both Balanced Transmission Mechanism (BTM) and EBET techniques. EBET selects relay node on the basis of optimal distance threshold which leads to network lifetime prolongation. The initial energy of each sensor node is divided into energy levels for balanced energy consumption. Selection of high energy level node within transmission range avoids long distance direct data transmission. The EEBET incorporates depth threshold to minimize the number of hops between source node and sink while eradicating backward data transmissions. The EBET technique balances energy consumption within successive ring sectors, while, EEBET balances energy consumption of the entire network. In EEBET, optimum number of energy levels are also calculated to further enhance the network lifetime. Effectiveness of the proposed schemes is validated through simulations where these are compared with two existing routing protocols in terms of network lifetime, transmission loss, and throughput. The simulations are conducted under different network radii and varied number of nodes. PMID:27070605

  15. Nintendo® Wii Fit based sleepiness tester detects impairment of postural steadiness due to 24 h of wakefulness.

    PubMed

    Tietäväinen, Aino; Gates, Fred K; Meriläinen, Antti; Mandel, Jeff E; Hæggström, Edward

    2013-12-01

    A field-usable sleepiness tester could reduce sleepiness related accidents. 15 subjects' postural steadiness was measured with a Nintendo(®) Wii Fit balance board every hour for 24 h. Body sway was quantified with complexity index, CI, and the correlation between CI and alertness predicted by a three-process model of sleepiness was calculated. The CI group average was 8.9 ± 1.3 for alert and 7.9 ± 1.4 for sleep deprived subjects (p < 0.001, ρ = 0.94). The Wii Fit board detects the impairment of postural steadiness. This may allow large scale sleepiness testing outside the laboratory setting. PMID:24054980

  16. Estimates of fluid and energy balances of Apollo 17

    NASA Technical Reports Server (NTRS)

    Johnson, P. C.; Leach, C. S.; Rambaut, P. C.

    1973-01-01

    Fluid and caloric balance has been calculated for the Apollo 17 crew. This included measurement of nitrogen, water, and caloric value of the ingested food and the volume and nitrogen content of the excreted urine and feces. Body composition changes were determined from total body water and extracellular fluid volume differences. The body composition measurements made it possible to divide the weight loss into lean body mass and adipose tissue losses. From this division a caloric equivalent was calculated. These tissue losses indicated that the caloric requirements of the mission were considerably greater than the actual caloric intake. The 3.3 kilo mean loss of body weight represented 1 kilo of lean body mass and 2.3 kilos of adipose tissue. Calculated fluid balance was more positive during the mission than during the control period. These changes are unlike the body composition and fluid balance changes reported in bedrested subjects.

  17. Balancing Area Coordination: Efficiently Integrating Renewable Energy Into the Grid, Greening the Grid

    SciTech Connect

    Katz, Jessica; Denholm, Paul; Cochran, Jaquelin

    2015-06-01

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. Coordinating balancing area operation can promote more cost and resource efficient integration of variable renewable energy, such as wind and solar, into power systems. This efficiency is achieved by sharing or coordinating balancing resources and operating reserves across larger geographic boundaries.

  18. Mass balance, energy and exergy analysis of bio-oil production by fast pyrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mass, energy and exergy balances are analyzed for bio-oil production in a bench scale fast pyrolysis system developed by the USDA’s Agricultural Research Service (ARS) for the processing of commodity crops to fuel intermediates. Because mass balance closure is difficult to achieve due, in part, to ...

  19. Evaluating surface energy balance system (SEBS) using aircraft data collected during BEAREX07

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evapotranspiration (ET) is an essential component of the water balance and a major consumptive use of irrigation water and precipitation on cropland. Remote sensing based surface energy balance algorithms are now capable of providing accurate estimates of spatial-temporal ET. Uses of these spatial E...

  20. Energy balance closure on a winter wheat stand: comparing the eddy covariance technique with the soil water balance method

    NASA Astrophysics Data System (ADS)

    Imukova, K.; Ingwersen, J.; Hevart, M.; Streck, T.

    2015-05-01

    The energy balance of eddy covariance (EC) flux data is typically not closed. The nature of the gap is usually not known, which hampers using EC data to parameterize and test models. The present study elucidates the nature of the energy gap of EC flux data from winter wheat stands in southwest Germany. During the vegetation periods 2012 and 2013, we continuously measured, in a half-hourly resolution, latent (LE) and sensible (H) heat fluxes using the EC technique. Measured fluxes were adjusted with either the Bowen-ratio (BR), H or LE post-closure method. The adjusted LE fluxes were tested against evapotranspiration data (ETWB) calculated using the soil water balance (WB) method. At sixteen locations within the footprint of an EC station, the soil water storage term was determined by measuring the soil water content down to a soil depth of 1.5 m. In the second year, the volumetric soil water content was also continuously measured in 15 min resolution in 10 cm intervals down to 90 cm depth with sixteen capacitance soil moisture sensors. During the 2012 vegetation period, the H post-closed LE flux data (ETEC = 3.4 ± 0.6 mm day-1) corresponded closest with the result of the WB method (3.3 ± 0.3 mm day-1). ETEC adjusted by the BR (4.1 ± 0.6 mm day-1) or LE (4.9 ± 0.9 mm day-1) post-closure method were higher than the ETWB by 20 and 33%, respectively. In 2013, ETWB was in best agreement with ETEC adjusted with the H post-closure method during the periods with low amount of rain and seepage. During these periods the BR and LE post-closure methods overestimated ET by about 30 and 40%, respectively. During a period with high and frequent rainfalls, ETWB was in-between ETEC adjusted by H and BR post-closure methods. We conclude that, at most vegetation periods on our site, LE is not a~major component of the energy balance gap. Our results indicate that the energy balance gap other energy fluxes and unconsidered or biased energy storage terms.

  1. Coherent Structure Patterns Affect Energy Balance Closure: Evidence from Virtual Measurements for a Field Campaign

    NASA Astrophysics Data System (ADS)

    Zhang, S.; De Roo, F.; Heinze, R.; Eder, F.; Huq, S.; Schmidt, M.; Kalthoff, N.; Mauder, M.

    2015-12-01

    The energy balance closure problem is a well-known issue of eddy-covariance measurements. However, the underlying mechanisms are still under debate. Recent evidence suggests that organized low-frequency motion contributes significantly to the energy balance residual, because the associated transport cannot be captured by a point measurement. In this study, we carry out virtual measurements using a PArallelized Large-Eddy Simulation Model (PALM). In order to represent specific measurement days of the field campaign "High definition clouds and precipitation for advancing climate prediction" (HD(CP)²), which was part of the project "High Definition Clouds and Precipitation for Advancing Climate Prediction"(HOPE) in 2013, the simulations were driven by synoptic-scale COSMO-DE reanalysis data. Planet boundary layer height, the vertical profiles of variance and skewness of vertical wind were analyzed and a comparison with Doppler-lidar observations shows good agreement. Furthermore, simulated energy imbalances were compared with real-world imbalances from two eddy-covariance stations in the model domain. Particularly poor energy balance closure was found for a day with cellular organized structures in the surface layer, while the energy balance closure was better on other days with roll-like structures. This finding might be one explanation why the energy balance closure generally tends to improve with increasing friction velocity, since roll-like structures are typically associated with higher wind speeds. In order to gain insight into the partitioning of the energy balance residual between the sensible and latent heat fluxes, we further employed a control volume method within the numerical simulation. Hence, advection and storage terms were identified as the most important causes for the lack of energy balance closure by the eddy-covariance method. The results of the virtual measurements indicate that the "missing" part of the surface energy mainly comes from the

  2. Energy balance closure on a winter wheat stand: comparing the eddy covariance technique with the soil water balance method

    NASA Astrophysics Data System (ADS)

    Imukova, K.; Ingwersen, J.; Hevart, M.; Streck, T.

    2016-01-01

    The energy balance of eddy covariance (EC) flux data is typically not closed. The nature of the gap is usually not known, which hampers using EC data to parameterize and test models. In the present study we cross-checked the evapotranspiration data obtained with the EC method (ETEC) against ET rates measured with the soil water balance method (ETWB) at winter wheat stands in southwest Germany. During the growing seasons 2012 and 2013, we continuously measured, in a half-hourly resolution, latent heat (LE) and sensible (H) heat fluxes using the EC technique. Measured fluxes were adjusted with either the Bowen-ratio (BR), H or LE post-closure method. ETWB was estimated based on rainfall, seepage and soil water storage measurements. The soil water storage term was determined at sixteen locations within the footprint of an EC station, by measuring the soil water content down to a soil depth of 1.5 m. In the second year, the volumetric soil water content was additionally continuously measured in 15 min resolution in 10 cm intervals down to 90 cm depth with sixteen capacitance soil moisture sensors. During the 2012 growing season, the H post-closed LE flux data (ETEC = 3.4 ± 0.6 mm day-1) corresponded closest with the result of the WB method (3.3 ± 0.3 mm day-1). ETEC adjusted by the BR (4.1 ± 0.6 mm day-1) or LE (4.9 ± 0.9 mm day-1) post-closure method were higher than the ETWB by 24 and 48 %, respectively. In 2013, ETWB was in best agreement with ETEC adjusted with the H post-closure method during the periods with low amount of rain and seepage. During these periods the BR and LE post-closure methods overestimated ET by about 46 and 70 %, respectively. During a period with high and frequent rainfalls, ETWB was in-between ETEC adjusted by H and BR post-closure methods. We conclude that, at most observation periods on our site, LE is not a major component of the energy balance gap. Our results indicate that the energy balance gap is made up by

  3. [Effect of diurnal distribution of food intake on 24-h profiles of plasma lipoproteins (author's transl)].

    PubMed

    Schneider, J; Tauber, H

    1981-02-16

    The lipid infiltration theory of atherogenesis accepted, 24 h lipoprotein profiles may be more relevant than preprandial morning samples. Such profiles were performed in 12 metabolically healthy volunteers during two dietetic regimes identical in total food content but differing in the distribution over the day: form A meant an evening meal of 15% of total caloric intake, form B of 40%. After one week of each form, 24 h lipoprotein profiles differed significantly in the time course of triglyceride rich lipoproteins and in the mean values over 24 h in VLDL and LDL phospholipids and HDL cholesterol. These findings are cautiously interpreted as possible signs of differences in the catabolism of triglyceride rich lipoproteins, remnants and intermediate lipoproteins. The difference in HDL cholesterol which was higher in form A is discussed in the context of recent epidemiologic evidence. PMID:7194945

  4. Incorporating elastic and plastic work rates into energy balance for long-term tectonic modeling

    NASA Astrophysics Data System (ADS)

    Ahamed, M. S.; Choi, E.

    2014-12-01

    Deformation-related energy budget is usually considered in the simplest form or even completely omitted from the energy balance equation. We derive an energy balance equation that accounts not only for heat energy but also for elastic and plastic work. Such a general description of the energy balance principle will be useful for modeling complicated interactions between geodynamic processes such as thermoelastisity, thermoplasticity and mechanical consequences of metamorphism. Following the theory of large deformation plasticity, we start from the assumption that Gibbs free energy (g) is a function of temperature (T), the second Piola-Kirchhoff stress (S), density (ρ) and internal variables (qj, j=1…n). In this formulation, new terms are derived, which are related to the energy dissipated through plastic work and the elastically stored energy that are not seen in the usual form of the energy balance equation used in geodynamics. We then simplify the generic equation to one involving more familiar quantities such as Cauchy stress and material density assuming that the small deformation formulation holds for our applications. The simplified evolution equation for temperature is implemented in DyanEarthSol3D, an unstructured finite element solver for long-term tectonic deformation. We calculate each of the newly derived terms separately in simple settings and compare the numerical results with a corresponding analytic solution. We also present the effects of the new energy balance on the evolution of a large offset normal fault.

  5. Developmental programming of energy balance regulation: Is physical activity more "programmable" than food intake?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extensive human and animal model data show that environmental influences during critical periods of prenatal and early postnatal development can cause persistent alterations in energy balance regulation. Although a potentially important factor in the worldwide obesity epidemic, the fundamental mecha...

  6. Analysis of energy balance models using the ERBE data set. Final Report

    SciTech Connect

    Graves, C.E.; North, G.R.

    1991-04-01

    A review of Energy Balance Models is presented. Results from the Outgoing Longwave Radiation parameterization are discussed. The albedo parameterizations and the consequences of the new parameterizations are examined.

  7. Towards a Sustainable Energy Balance: Progressive Efficiency and the Return of Energy Conservation

    SciTech Connect

    Diamond, Rick; Harris, Jeff; Diamond, Rick; Iyer, Maithili; Payne, Christopher; Blumstein, Carl; Siderius, Hans-Paul

    2007-08-13

    We argue that a primary focus on energy efficiency may not be sufficient to slow (and ultimately reverse) the growth in total energy consumption and carbon emissions. Instead, policy makers need to return to an earlier emphasis on"conservation," with energy efficiency seen as a means rather than an end in itself. We briefly review the concept of"intensive" versus"extensive" variables (i.e., energy efficiency versus energy consumption), and why attention to both consumption and efficiency is essential for effective policy in a carbon- and oil-constrained world with increasingly brittle energy markets. To start, energy indicators and policy evaluation metrics need to reflect energy consumption as well as efficiency. We introduce the concept of"progressive efficiency," with the expected or required level of efficiency varying as a function of house size, appliance capacity, or more generally, the scale of energy services. We propose introducing progressive efficiency criteria first in consumer information programs (including appliance labeling categories) and then in voluntary rating and recognition programs such as ENERGY STAR. As acceptance grows, the concept could be extended to utility rebates, tax incentives, and ultimately to mandatory codes and standards. For these and other programs, incorporating criteria for consumption as well as efficiency offers a path for energy experts, policy-makers, and the public to begin building consensus on energy policies that recognize the limits of resources and global carrying-capacity. Ultimately, it is both necessary and, we believe, possible to manage energy consumption, not just efficiency in order to achieve a sustainable energy balance. Along the way, we may find it possible to shift expectations away from perpetual growth and toward satisfaction with sufficiency.

  8. Cardiovascular and thermoregulatory dysregulation over 24 h following acute heat stress in rats.

    PubMed

    Quinn, Carrie M; Audet, Gerald N; Charkoudian, Nisha; Leon, Lisa R

    2015-08-15

    The influences of severe heat stroke (HS) on cardiovascular function during recovery are incompletely understood. We hypothesized that HS would elicit a heart rate (HR) increase persisting through 24 h of recovery due to hemodynamic, thermoregulatory, and inflammatory events, necessitating tachycardia to support mean arterial pressure (MAP). Core temperature (Tc), HR, and MAP were measured via radiotelemetry in conscious male Fischer 344 rats (n = 22; 282.4 ± 3.5 g) during exposure to 37°C ambient temperature until a maximum Tc of 42.0°C, and during recovery at 20°C ambient temperature through 24 h. Rats were divided into Mild, Moderate, and Severe groups based on pathophysiology. HS rats exhibited hysteresis relative to Tc with HR higher for a given Tc during recovery compared with heating (P < 0.0001). "Reverse" hysteresis occurred in MAP with pressure during cooling lower than heating per degree Tc (P < 0.0001). Mild HS rats showed tachycardia [P < 0.01 vs. control (Con)] through 8 h of recovery, elevated MAP (P < 0.05 vs. Con) for the initial 5 h of recovery, with sustained hyperthermia (P < 0.05 vs. Con) through 24 h. Moderate HS rats showed significant tachycardia (P < 0.01 vs. Con), normal MAP (P > 0.05 vs. Con), and rebound hyperthermia from 4 to 24 h post-HS (P < 0.05 vs. Con). Severe HS rats showed tachycardia (P < 0.05 vs. Con), hypotension (P < 0.01 vs. Con), and hypothermia for 24 h (P < 0.05 vs. Con). Severe HS rats showed 14- and 12-fold increase in heart and liver inducible nitric oxide synthase expression, respectively. Hypotension and hypothermia in Severe HS rats was consistent with inducible nitric oxide synthase-mediated systemic vasodilation. These findings provide mechanistic insight into hemodynamic and thermoregulatory impairments during 24 h of HS recovery. PMID:26071550

  9. Effects of winter military training on energy balance, whole-body protein balance, muscle damage, soreness, and physical performance.

    PubMed

    Margolis, Lee M; Murphy, Nancy E; Martini, Svein; Spitz, Marissa G; Thrane, Ingjerd; McGraw, Susan M; Blatny, Janet-Martha; Castellani, John W; Rood, Jennifer C; Young, Andrew J; Montain, Scott J; Gundersen, Yngvar; Pasiakos, Stefan M

    2014-12-01

    Physiological consequences of winter military operations are not well described. This study examined Norwegian soldiers (n = 21 males) participating in a physically demanding winter training program to evaluate whether short-term military training alters energy and whole-body protein balance, muscle damage, soreness, and performance. Energy expenditure (D2(18)O) and intake were measured daily, and postabsorptive whole-body protein turnover ([(15)N]-glycine), muscle damage, soreness, and performance (vertical jump) were assessed at baseline, following a 4-day, military task training phase (MTT) and after a 3-day, 54-km ski march (SKI). Energy intake (kcal·day(-1)) increased (P < 0.01) from (mean ± SD (95% confidence interval)) 3098 ± 236 (2985, 3212) during MTT to 3461 ± 586 (3178, 3743) during SKI, while protein (g·kg(-1)·day(-1)) intake remained constant (MTT, 1.59 ± 0.33 (1.51, 1.66); and SKI, 1.71 ± 0.55 (1.58, 1.85)). Energy expenditure increased (P < 0.05) during SKI (6851 ± 562 (6580, 7122)) compared with MTT (5480 ± 389 (5293, 5668)) and exceeded energy intake. Protein flux, synthesis, and breakdown were all increased (P < 0.05) 24%, 18%, and 27%, respectively, during SKI compared with baseline and MTT. Whole-body protein balance was lower (P < 0.05) during SKI (-1.41 ± 1.11 (-1.98, -0.84) g·kg(-1)·10 h) than MTT and baseline. Muscle damage and soreness increased and performance decreased progressively (P < 0.05). The physiological consequences observed during short-term winter military training provide the basis for future studies to evaluate nutritional strategies that attenuate protein loss and sustain performance during severe energy deficits. PMID:25386980

  10. Alterations in amino acid concentrations in the plasma and muscle in human subjects during 24 h of simulated adventure racing.

    PubMed

    Borgenvik, Marcus; Nordin, Marie; Mikael Mattsson, C; Enqvist, Jonas K; Blomstrand, Eva; Ekblom, Björn

    2012-10-01

    This investigation was designed to evaluate changes in plasma and muscle levels of free amino acids during an ultra-endurance exercise and following recovery. Nine male ultra-endurance trained athletes participated in a 24-h standardized endurance trial with controlled energy intake. The participants performed 12 sessions of running, kayaking and cycling (4 × each discipline). Blood samples were collected before, during and after exercise, as well as after 28 h of recovery. Muscle biopsies were taken before the test and after exercise, as well as after 28 h of recovery. During the 24-h exercise, plasma levels of branched-chain (BCAA), essential amino acids (EAA) and glutamine fell 13, 14 and 19% (P < 0.05), respectively, whereas their concentrations in muscle were unaltered. Simultaneously, tyrosine and phenylalanine levels rose 38 and 50% (P < 0.05) in the plasma and 66 and 46% (P < 0.05) in muscle, respectively. After the 24-h exercise, plasma levels of BCAA were positively correlated with muscle levels of glycogen (r (2) = 0.73, P < 0.05), as was the combined concentrations of muscle tyrosine and phenylalanine with plasma creatine kinase (R (2) = 0.55, P < 0.05). Following 28-h of recovery, plasma and muscle levels of amino acids had either returned to their initial levels or were elevated. In conclusion, ultra-endurance exercise caused significant changes elevations in plasma and muscle levels of tyrosine and phenylalanine, which suggest an increase in net muscle protein breakdown during exercise. There was a reduction in plasma concentrations of EAA and glutamine during exercise, whereas no changes were detected in their muscle concentration after exercise. PMID:22350359

  11. Influence of momentum dependent interactions on the fragment structures at balance energies

    NASA Astrophysics Data System (ADS)

    Chugh, Rajiv; Kumar, Rohit

    2016-05-01

    We study the role of momentum-dependent interactions on fragment structures at balance energies for semi-peripheral collisions over a wide range of system masses using quantum molecular dynamics (QMD) model. We find a meagre role of momentum-dependent interactions for fragments in case of lighter system masses. But as we go towards higher system masses, the effect of momentum-dependent interactions increases for free nucleons, light charged particles and intermediate mass fragments at corresponding balance energies.

  12. OBERON: OBliquity and Energy balance Run on N-body systems

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan H.

    2016-08-01

    OBERON (OBliquity and Energy balance Run on N-body systems) models the climate of Earthlike planets under the effects of an arbitrary number and arrangement of other bodies, such as stars, planets and moons. The code, written in C++, simultaneously computes N body motions using a 4th order Hermite integrator, simulates climates using a 1D latitudinal energy balance model, and evolves the orbital spin of bodies using the equations of Laskar (1986a,b).

  13. To ingest or rest? Specialized roles of lateral hypothalamic area neurons in coordinating energy balance

    PubMed Central

    Brown, Juliette A.; Woodworth, Hillary L.; Leinninger, Gina M.

    2015-01-01

    Survival depends on an organism’s ability to sense nutrient status and accordingly regulate intake and energy expenditure behaviors. Uncoupling of energy sensing and behavior, however, underlies energy balance disorders such as anorexia or obesity. The hypothalamus regulates energy balance, and in particular the lateral hypothalamic area (LHA) is poised to coordinate peripheral cues of energy status and behaviors that impact weight, such as drinking, locomotor behavior, arousal/sleep and autonomic output. There are several populations of LHA neurons that are defined by their neuropeptide content and contribute to energy balance. LHA neurons that express the neuropeptides melanin-concentrating hormone (MCH) or orexins/hypocretins (OX) are best characterized and these neurons play important roles in regulating ingestion, arousal, locomotor behavior and autonomic function via distinct neuronal circuits. Recently, another population of LHA neurons containing the neuropeptide Neurotensin (Nts) has been implicated in coordinating anorectic stimuli and behavior to regulate hydration and energy balance. Understanding the specific roles of MCH, OX and Nts neurons in harmonizing energy sensing and behavior thus has the potential to inform pharmacological strategies to modify behaviors and treat energy balance disorders. PMID:25741247

  14. The National Energy Strategy: A balanced program?. Proceedings of the nineteenth annual Illinois energy conference

    SciTech Connect

    Not Available

    1991-12-31

    The Nineteenth Annual Illinois Energy Conference was held in Chicago, Illinois November 1991. It was organized by the Energy Resources Center, University of Illinois at Chicago with major support provided by the US Environmental Protection Agency, the US Department of Energy, the Illinois Commerce Commission, the Illinois Department of Energy and Natural Resources, and the Citizens Council on Energy Resources. The conference program was developed by a planning committee who drew upon Illinois energy and environmental specialists from the major sectors including energy industries, environmental organizations, research universities, utility companies, federal, state and local government agencies, and public interest groups. The members of the planning committee were brought together for a full-day session where they were asked to assess the political, economic, and social impacts of the proposed National Energy Strategy as it relates to Illinois and the Midwest region. Within this context, the planning committee identified several major issues including: (1) Is the proposed plan a balanced strategy; (2) What are the NES impacts on the transportation sector; (3) What are the opportunities for improved efficiency in the Electric Utility Sector; and (4) What is the role of advanced research and development.

  15. Surface energy budget and mass balance of Zhadang Glacier in the central Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Li, B.; Acharya, K.; Yu, Z.; Su, F.; liang, Z.

    2011-12-01

    It is difficult to clearly investigate the surface energy budget and glacier evolution under the changed climate environments, especially on accounts of limited data set. We attempted to calculate the summer mass balance of Zhadang Glacier (5710 m above sea level), located in the central Tibetan Plateau. This small and high-altitude glacier has been retreating during the previous decades. Energy balance was calculated on a 30 m square grid on the glacier for the summer periods in 2007 and 2008. On average, net radiation contributed more than 96% of the energy gain while only less than 4% was supplied by the sensible heat flux. Most energy loss on the glacier was contributed by the turbulent heat fluxes and only roughly 30% of the total energy was available for melting. A large deficit and a surplus summer mass balance were obtained for years 2006/07 and 2007/08, respectively. The switch in mass balance from negative to positive in the summer of 2008 is caused by early precipitation (mostly snow) resulting in low temperature on the glacier. Low temperature produces less energy that contributes to melting, whereas increased snow accumulation produces higher surface albedo reflecting away incoming solar radiation. The high sensitivity of air temperature may imply that the low temperature was more important than the increased precipitation in the mass balance switch in Zhadang Glacier. Despite a continuous negative mass balance for several decades in Zhadang Glacier 2008 may have brought a temporary relief.

  16. Water and energy balances in the soil-plant atmosphere continuum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy fluxes at soil-atmosphere and plant-atmosphere interfaces can be summed to zero because the surfaces have no capacity for energy storage. The resulting energy balance equations may be written in terms of physical descriptions of these fluxes; and have been the basis for problem casting and so...

  17. Energy balance and plume dynamics in Triton's lower atmosphere

    SciTech Connect

    Yelle, R.V.; Lunine, J.I.; Hunten, D.M. )

    1991-02-01

    The present study of the thermal balance-affecting relationships among Triton lower atmosphere thermal conduction, eddy mixing, condensation, and radiative heating indicates that, while the temperature gradient is negative in the lower atmosphere, it becomes positive at higher altitudes due to the downward conduction of ionospheric heat. This temperature profile is essentially consistent with radio-occultation experiment data; the geyser-like plumes observed by Voyager suggest that the Trioton atmosphere's convective and conductive regions join near 10-km altitude, and that the values inferred for the eddy diffusion and heat-transport coefficients indicate a profile reminiscent of the earth's. 28 refs.

  18. Energy balance and plume dynamics in Triton's lower atmosphere

    NASA Technical Reports Server (NTRS)

    Yelle, Roger V.; Lunine, Jonathan I.; Hunten, Donald M.

    1991-01-01

    The present study of the thermal balance-affecting relationships among Triton lower atmosphere thermal conduction, eddy mixing, condensation, and radiative heating indicates that, while the temperature gradient is negative in the lower atmosphere, it becomes positive at higher altitudes due to the downward conduction of ionospheric heat. This temperature profile is essentially consistent with radio-occultation experiment data; the geyser-like plumes observed by Voyager suggest that the Trioton atmosphere's convective and conductive regions join near 10-km altitude, and that the values inferred for the eddy diffusion and heat-transport coefficients indicate a profile reminiscent of the earth's.

  19. The Role of PVH Circuits in Leptin Action and Energy Balance.

    PubMed

    Sutton, Amy K; Myers, Martin G; Olson, David P

    2016-01-01

    Although it has been known for more than a century that the brain controls overall energy balance and adiposity by regulating feeding behavior and energy expenditure, the roles for individual brain regions and neuronal subtypes were not fully understood until recently. This area of research is active, and as such our understanding of the central regulation of energy balance is continually being refined as new details emerge. Much of what we now know stems from the discoveries of leptin and the hypothalamic melanocortin system. Hypothalamic circuits play a crucial role in the control of feeding and energy expenditure, and within the hypothalamus, the arcuate nucleus (ARC) functions as a gateway for hormonal signals of energy balance, such as leptin. It is also well established that the ARC is a primary residence for hypothalamic melanocortinergic neurons. The paraventricular hypothalamic nucleus (PVH) receives direct melanocortin input, along with other integrated signals that affect energy balance, and mediates the majority of hypothalamic output to control both feeding and energy expenditure. Herein, we review in detail the structure and function of the ARC-PVH circuit in mediating leptin signaling and in regulating energy balance. PMID:26863324

  20. Soil Moisture Modeling Using Two Energy Balance Approaches with Thermal Infrared Satellite Inputs

    NASA Astrophysics Data System (ADS)

    Neale, C. M.; Gonzalez Dugo, M. P.; Anderson, M.; Li, F.; Kustas, W. P.

    2006-12-01

    The paper describes the results from a modeling effort using two energy balance approaches for estimating latent heat fluxes and daily evapotranspiration. The two models are (1) a one-layer empirically based energy balance model (OLEM) described by Chavez et al, (2005) and (2) the Two-source model (TSM) by Norman et al, (1995) modified by Li et al, (2005). The instantaneous derived latent heat fluxes are extrapolated to daily values of evapotranspiration using different approaches and over time in between Landsat TM acquisition dates. The energy balance model results are used as inputs to a soil moisture balance model. Comparisons of the remotely sensed fluxes with tower measured fluxes are conducted along with comparisons between modeled and measured soil moisture during the intensive period of the SMACEX study (Kustas et al, 2005), in a rain fed corn and soybean cropped area close to Ames, Iowa.

  1. Mass and thermal energy balance of potato processing operations

    SciTech Connect

    Chadbourne, D.L.; Heldman, D.R.

    1981-01-01

    A mass and thermal energy analysis was conducted for a potato peeling operation. Results provide insight into opportunities for process modifications leading to increased recovery of product components and thermal energy.

  2. NQRS Data for C24H24BN (Subst. No. 1583)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H24BN (Subst. No. 1583)

  3. NQRS Data for C24H20BCs (Subst. No. 1575)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H20BCs (Subst. No. 1575)

  4. NQRS Data for C24H20BRb (Subst. No. 1578)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C24H20BRb (Subst. No. 1578)

  5. 24-h fluid kinetics and perception of sweat losses following a 1-h run in a temperate environment.

    PubMed

    O'Neal, Eric K; Caufield, Christina R; Lowe, Jordan B; Stevenson, Mary C; Davis, Brett A; Thigpen, Lauren K

    2014-01-01

    This study examined 24-h post-run hydration status and sweat loss estimation accuracy in college age runners (men=12, women=8) after completing a 1-h self-paced outdoor run (wet bulb globe temperature=19.9±3.0 °C). Sweat losses (1353±422 mL; 1.9%±0.5% of body mass) were significantly greater (p<0.001) than perceived losses (686±586 mL). Cumulative fluid consumption equaled 3876±1133 mL (218±178 mL during) with 37% of fluid ingested lost through urine voids (1450±678 mL). Fluid balance based on intake and urine production equaled +554±669 mL at 12 h and +1186±735 mL at 24 h. Most runners reported euhydrated (pre-run urine specific gravity (USG)=1.018±0.008) with no changes (p=0.33) at hours 12 or 24 when both genders were included. However, USG was higher (p=0.004) at 12 h post-run for men (1.025±0.0070 vs. 1.014±0.007), who consumed 171%±40% of sweat losses at 12 h vs. 268%±88% for women. Most runners do not need intervention concerning between bout hydration needs in temperate environments. However, repeated USG measurements were able to identify runners who greatly under or over consumed fluid during recovery. Practitioners can use multiple USG assessments as cheap method to detect runners who need to modify their hydration strategies and should promote assessment of sweat losses by change in body mass, as runners had poor perception of sweat losses. PMID:24451307

  6. 24-h Fluid Kinetics and Perception of Sweat Losses Following a 1-h Run in a Temperate Environment

    PubMed Central

    O’Neal, Eric K.; Caufield, Christina R.; Lowe, Jordan B.; Stevenson, Mary C.; Davis, Brett A.; Thigpen, Lauren K.

    2013-01-01

    This study examined 24-h post-run hydration status and sweat loss estimation accuracy in college age runners (men = 12, women = 8) after completing a 1-h self-paced outdoor run (wet bulb globe temperature = 19.9 ± 3.0 °C). Sweat losses (1353 ± 422 mL; 1.9% ± 0.5% of body mass) were significantly greater (p < 0.001) than perceived losses (686 ± 586 mL). Cumulative fluid consumption equaled 3876 ± 1133 mL (218 ± 178 mL during) with 37% of fluid ingested lost through urine voids (1450 ± 678 mL). Fluid balance based on intake and urine production equaled +554 ± 669 mL at 12 h and +1186 ± 735 mL at 24 h. Most runners reported euhydrated (pre-run urine specific gravity (USG) = 1.018 ± 0.008) with no changes (p = 0.33) at hours 12 or 24 when both genders were included. However, USG was higher (p = 0.004) at 12 h post-run for men (1.025 ± 0.0070 vs. 1.014 ± 0.007), who consumed 171% ± 40% of sweat losses at 12 h vs. 268% ± 88% for women. Most runners do not need intervention concerning between bout hydration needs in temperate environments. However, repeated USG measurements were able to identify runners who greatly under or over consumed fluid during recovery. Practitioners can use multiple USG assessments as cheap method to detect runners who need to modify their hydration strategies and should promote assessment of sweat losses by change in body mass, as runners had poor perception of sweat losses. PMID:24451307

  7. Energy balance in the solar transition region. I - Hydrostatic thermal models with ambipolar diffusion

    NASA Technical Reports Server (NTRS)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1990-01-01

    The energy balance in the lower transition region is analyzed by constructing theoretical models which satisfy the energy balance constraint. The energy balance is achieved by balancing the radiative losses and the energy flowing downward from the corona. This energy flow is mainly in two forms: conductive heat flow and hydrogen ionization energy flow due to ambipolar diffusion. Hydrostatic equilibrium is assumed, and, in a first calculation, local mechanical heating and Joule heating are ignored. In a second model, some mechanical heating compatible with chromospheric energy-balance calculations is introduced. The models are computed for a partial non-LTE approach in which radiation departs strongly from LTE but particles depart from Maxwellian distributions only to first order. The results, which apply to cases where the magnetic field is either absent, or uniform and vertical, are compared with the observed Lyman lines and continuum from the average quiet sun. The approximate agreement suggests that this type of model can roughly explain the observed intensities in a physically meaningful way, assuming only a few free parameters specified as chromospheric boundary conditions.

  8. On the study of energy imbalance and its influence on estimation of heat fluxes using energy balance based models

    NASA Astrophysics Data System (ADS)

    Jia, L.; Zhang, T.; Su, Z.

    2003-04-01

    The modeling of evapotranspiration from land surface has long been an important issue in many research fields, e.g. the energy partition and water cycles of the global climate system. Two methods are widely used to estimate evapotranspiration in hydrology and climatology. In the residual method the latent heat flux is estimated as the residual of energy balance equation, while in the combination equation the energy balance is combined with a transfer equation to calculate the evaporative fraction. Both methods are built up on the basis of energy balance between the available energy and the sum of sensible and latent heat fluxes if photosynthesis, the heat storage and the advection are neglected. However, the imbalance between the available energy (the residual of net radiation and the soil heat flux) and the sum of sensible and latent heat fluxes has been often observed during several field experiments, such as FIFE, HEIFE, and GAME-Tibet and the TIPEX. The reasons of the lack of closure in energy balance may attribute to various sources and can be put into two categories: (1) incompleteness in measurements including inadequate instrumentation and less representative fetch and insufficient sampling and too short averaging time; (2) incompleteness in the consideration of energy balance terms because many other processes may have non negligible contributions to the energy budget to some degrees depending on the complexity of the land surface. These may bring problem both to the evaluation of energy balance based models and to the framework on which the model is constructed. In this study, the imbalance problem is investigated by the analysis of the data collected in the filed measurements during GAME-Tibet and TIPEX. As a further study, a validated model SEBS using many other datasets is used to clarify the impact of such imbalance to the energy-balance based models. A correction method is proposed to solve the imbalance problems existing in collected data.

  9. Control and Size Energy Storage for Managing Energy balance of Variable Generation Resources

    SciTech Connect

    Ke, Xinda; Lu, Ning; Jin, Chunlian

    2015-01-01

    This paper presents control algorithms and sizing strategies for using energy storage to manage energy balance for variable generation resources. The control objective is to minimize the hourly generation imbalance between the actual and the scheduled generation of the wind farm. Three control algorithms are compared: tracking power imbalance, post-compensation, and pre-compensation. Measurement data from a wind farm located in South-central Washington State are used in the study. The results show that tracking power imbalance yields the best performance by keeping the hourly energy imbalances zero. However, the energy storage system (ESS) will be significantly oversized. Post-compensation reduces power rating of the ESS but the hourly imbalance may not be kept as zero when large and long-lasting energy imbalances occur. A linear regression forecasting algorithm is developed for the pre-compensation algorithm to pre-charge or pre-discharge the ESS based on predicted energy imbalances. The performance comparison shows that the pre-compensation method significantly reduces the size of the ESS while maintaining satisfactory performance.

  10. Energy Balance and Turbulent Flux Partitioning in a Corn-soybean Rotation in the Midwestern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy balance at soil surface-canopy interface is critical for better understanding of water balance and changes in regional weather patterns; however, limited long-term, year-round studies have been conducted in agricultural fields. This study was carried out to assess energy balance closure and p...

  11. A "second window of protection" occurs 24 h after ischemic preconditioning in the rat heart.

    PubMed

    Yamashita, N; Hoshida, S; Taniguchi, N; Kuzuya, T; Hori, M

    1998-06-01

    We and others found that cardioprotection is acquired not only soon after, but also 24 h after ischemic preconditioning in canine and rabbit myocardial infarction models (second window of protection). However, a second window phenomenon against myocardial infarction was dependent on species limitations and has not been observed in porcine hearts. In this study, we examined whether the "second window of protection" against myocardial infarction is observed in the rat heart. In the ischemic preconditioning (IP) group, the left main coronary artery (LCA) of rats was occluded four times for 3 min. each separated by reperfusion for 10 min. After 0, 3, and 24 h, the rats were subjected to a 20-min LCA occlusion followed by 48-h reperfusion. At 0 and 24 h after IP, infarct size and the incidence of ventricular fibrillation (VF) during ischemia were significantly reduced compared with corresponding sham-operated groups without preconditioning. After 3 h of IP, there were no differences either in the incidence of VF during ischemia or in infarct size. Manganese superoxide dismutase (Mn-SOD) content in ischemic (LCA) region of myocardium significantly increased as compared with that of sham-operated rats 24 h after IP. Treatment with N-2-mercaptopropionyl glycine, an antioxidant and a hydroxyl radical scavenger, during IP abolished the early-phase (0 h after IP) and late-phase (24 h after IP) cardioprotection and the corresponding late increase in Mn-SOD content. These results indicate that a "second window of protection" against myocardial infarction also exists in rat hearts and the induction of an intrinsic scavenger, Mn-SOD, via free radical production during IP may be important in the second window of protection. PMID:9689592

  12. [The effect of chemotherapy on energy and nitrogen balance in patients with hematologic neoplasms].

    PubMed

    Tomíska, M; Dastych, M; Dolezalová, J; Vorlícek, J

    1997-01-01

    Energy balance and nitrogen balance were evaluated within the opening week of standard induction chemotherapy in 26 haematooncological patients. The patients were uncomplicated in good nutritional status and nutritional requirements were covered by oral diet under the daily assistance of specially trained dietary nurse. Resting energy expenditure (REE) measured by indirect calorimetry under standard circumstances was elevated to 113.1% of predicted value by Harris-Benedict equation. We found a significant decrease in REE to 106.1% of predicted value (p < 0.01) on day 7 after the beginning of induction chemotherapy. Total energy requirements calculated on the basis of measured REE were not elevated during chemotherapy and mean energy balance was balanced. On the other hand mean nitrogen balance was markedly negative during chemotherapy even on the second day of treatment (-6.9 gN/day, cumulative nitrogen balance -28.0 gN/5 days). The negativity correlated will with markedly elevated urinary nitrogen output but worse with nitrogen intake in the diet. Significant correlation was found between the negativity of cumulative nitrogen balance for the whole period of follow up and the magnitude of decrease in REE after chemotherapy (r = 0.74, p < 0.01). This dependence may give evidence of the decay of tumor mass as the main factor of changes shown. Findings described here may support the assumption that energy requirements of haematooncological patients in good nutrition status during chemotherapy may be covered by oral diet even though this usually does not prevent the negativity of nitrogen balance. PMID:9221560

  13. Parametrization of ambient energy harvesters for complementary balanced electronic applications

    NASA Astrophysics Data System (ADS)

    Verbelen, Yannick; Braeken, An; Touhafi, Abdellah

    2013-05-01

    The specific technical challenges associated with the design of an ambient energy powered electronic system currently requires thorough knowledge of the environment of deployment, energy harvester characteristics and power path management. In this work, a novel flexible model for ambient energy harvesters is presented that allows decoupling of the harvester's physical principles and electrical behavior using a three dimensional function. The model can be adapted to all existing harvesters, resulting in a design methodology for generic ambient energy powered systems using the presented model. Concrete examples are included to demonstrate the versatility of the presented design in the development of electronic appliances on system level.

  14. On the Linearly-Balanced Kinetic Energy Spectrum

    NASA Technical Reports Server (NTRS)

    Lu, Huei,-Iin; Robertson, F. R.

    1999-01-01

    It is well known that the earth's atmospheric motion can generally be characterized by the two dimensional quasi-geostrophic approximation, in which the constraints on global integrals of kinetic energy, entrophy and potential vorticity play very important roles in redistributing the wave energy among different scales of motion. Assuming the hypothesis of Kolmogrov's local isotropy, derived a -3 power law of the equilibrium two-dimensional kinetic energy spectrum that entails constant vorticity and zero energy flows from the energy-containing wave number up to the viscous cutoff. In his three dimensional quasi-geostrophic theory, showed that the spectrum function of the vertical scale turbulence - expressible in terms of the available potential energy - possesses the same power law as the two dimensional kinetic energy spectrum. As the slope of kinetic energy spectrum in the inertial range is theoretically related to the predictability of the synoptic scales (Lorenz, 1969), many general circulation models includes a horizontal diffusion to provide reasonable kinetic energy spectra, although the actual power law exhibited in the atmospheric general circulation is controversial. Note that in either the atmospheric modeling or the observational analyses, the proper choice of wave number Index to represent the turbulence scale Is the degree of the Legendre polynomial.

  15. Energy balance-dependent regulation of ovine glucose 6-phosphate dehydrogenase protein isoform expression.

    PubMed

    Triantaphyllopoulos, Kostas A; Laliotis, George P; Bizelis, Iosif A

    2014-01-01

    G6PDH is the rate-limiting enzyme of the pentose phosphate pathway and one of the principal source of NADPH, a major cellular reductant. Importantly, in ruminant's metabolism the aforementioned NADPH provided, is utilized for de novo fatty acid synthesis. Previous work of cloning the ovine (Ovis aries) og6pdh gene has revealed the presence of two cDNA transcripts (og6pda and og6pdb), og6pdb being a product of alternative splicing not similar to any other previously reported.(1) In the current study the effect of energy balance in the ovine G6PDH protein expression was investigated, shedding light on the biochemical features and potential physiological role of the oG6PDB isoform. Changes in energy balance leads to protein expression changes in both transcripts, to the opposite direction and not in a proportional way. Negative energy balance was not in favor of the presence of any particular isoform, while both protein expression levels were not significantly different (P > 0.05). In contrast, at the transition point from negative to positive and on the positive energy balance, there is a significant increase of oG6PDA compared with oG6PDB protein expression (P < 0.001). Both oG6PDH protein isoforms changed significantly toward the positive energy balance. oG6PDA is escalating, while oG6PDB is falling, under the same stimulus (positive energy balance alteration). This change is also positively associated with increasing levels in enzyme activity, 4 weeks post-weaning in ewes' adipose tissue. Furthermore, regression analysis clearly demonstrated the linear correlation of both proteins in response to the WPW, while energy balance, enzyme activity, and oG6PDA relative protein expression follow the same escalating trend; in contrast, oG6PDB relative protein expression falls in time, similar to both transcripts accumulation pattern, as reported previously.(2.) PMID:24575366

  16. Integration of microalgae systems at municipal wastewater treatment plants: implications for energy and emission balances.

    PubMed

    Menger-Krug, Eve; Niederste-Hollenberg, Jutta; Hillenbrand, Thomas; Hiessl, Harald

    2012-11-01

    Integrating microalgae systems (MAS) at municipal wastewater treatment plants (WWTPs) to produce of bioenergy offers many potential synergies. Improved energy balances provide a strong incentive for WWTPs to integrate MAS, but it is crucial that WWTPs maintain their barrier function to protect water resources. We perform a prospective analysis of energy and emission balances of a WWTP with integrated MAS, based on a substance flow analysis of the elements carbon (C), nitrogen (N), and phosphorus (P). These elements are the main ingredients of wastewater, and the key nutrients for algae growth. We propose a process design which relies solely on resources from wastewater with no external input of water, fertilizer or CO(2). The whole process chain, from cultivation to production of bioelectricity, takes place at the WWTP. Our results show that MAS can considerably improve energy balances of WWTPs without any external resource input. With optimistic assumptions, they can turn WWTPs into net energy producers. While intensive C recycling in MAS considerably improves the energy balance, we show that it also impacts on effluent quality. We discuss the importance of nonharvested biomass for effluent quality and highlight harvesting efficiency as key factor for energy and emission balances of MAS at WWTP. PMID:23050661

  17. Energy balance of biofuel production from biological conversion of crude glycerol.

    PubMed

    Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar D; Surampalli, Rao Y; Valéro, Jose R

    2016-04-01

    Crude glycerol, a by-product of biodiesel production, has gained significant attention as a carbon source for biofuel production. This study evaluated the energy balance of biodiesel, hydrogen, biogas, and ethanol production from 3.48 million L of crude glycerol (80% w/v). The conversion efficiency (energy output divided by energy invested) was 1.16, 0.22, 0.27, and 0.40 for the production of biodiesel, hydrogen, biogas, and ethanol respectively. It was found that the use of crude glycerol for biodiesel production was an energy gain process, with a positive energy balance and conversion efficiency of greater than 1. The energy balance revealed a net energy gain of 5226 GJ per 1 million kg biodiesel produced. Production of hydrogen, biogas and ethanol from crude glycerol were energy loss processes. Therefore, the conversion of crude glycerol to lipids and subsequently to biodiesel is suggested to be a better option compared to hydrogen, biogas, or ethanol production with respect to energy balance. PMID:26829450

  18. Breed and parity effects on energy balance profiles through lactation: evidence of genetically driven body energy change.

    PubMed

    Friggens, N C; Berg, P; Theilgaard, P; Korsgaard, I R; Ingvartsen, K L; Løvendahl, P; Jensen, J

    2007-11-01

    The aim of this study was to characterize patterns of energy balance through lactation of cows kept under constant feeding conditions. Danish Holstein, Danish Red, and Jersey cows were studied during consecutive lactations and remained on the same dietary treatment throughout. They were fed a normal (13.55 MJ of digestible energy/kg of dry matter) or a lower energy diet (12.88 MJ of digestible energy/kg of dry matter) ad libitum throughout lactation. Energy balance was calculated using the effective energy (EE) system in such a way that energy balance equated to body energy reserve change. In the EE system the energy values assigned to feeds are directly equivalent to the energy requirements of the animal; 1 MJ of EE supply has the same energy value as 1 MJ of lipid loss from the body. The resulting body energy change data were analyzed using a linear spline model. There was no evidence to suggest that different combinations of breed and parity required different knot placements. The Holstein mobilized significantly more body energy in early lactation than the Danish Red and Jersey breeds. Parity 1 cows mobilized significantly less than parity 2 and 3 cows. There was a significant interaction between breed and parity in the first half of lactation due to parity 1 Jersey cows having a greater mobilization than would be expected of the difference between parities in the other breeds. As lactation progressed, the differences between parities and between breeds decreased. Cows on the higher energy diet had a more positive energy balance. Within breed and parity, the following possible predictors of individual differences in body energy change were examined: fatness-corrected live weight, condition score at calving, and genotype. There was no difference in the predicted cow effect or residual energy balance profile when grouped according to quartiles of corrected live weight or according to condition score at calving. During the period of most negative energy balance (d

  19. Energy Crops and their Implications on Soil Carbon Sequestration, Surface Energy and Water Balance

    NASA Astrophysics Data System (ADS)

    Song, Y.; Barman, R.; Jain, A. K.

    2011-12-01

    The quest to meet growing energy demand with low greenhouse gas emissions has increased attention on the potential of existing and advanced biomass energy crops. Potential energy crops include row crops such as corn, and perennial grasses such as switchgrass. However, a massive expansion of bioenergy crops raises many questions such as: how and where to grow energy crops; and what will be the impacts of growing large scale biofuel crops on the terrestrial hydrological cycle, the surface energy budget, soil carbon sequestration and the concurrent effects on the climate system. An integrated modeling system is being developed with in the framework of a land surface model, the Integrated Science Assessment Model (ISAM), and being applied to address these questions.This framework accounts for the biophysical, physiological and biogeochemical systems governing important processes that regulate crop growth including water, energy and nutrient cycles within the soil-plant-atmosphere system. One row crop (Corn) and two energy crops (Switchgrass and Miscanthus) are studied in current framework. Dynamic phenology processes and parameters for simulating each crop have been developed using observed data from a north to south gradient of field trial sites. This study will specifically focus on the agricultural regions in the US and in Europe. The potential productivity of these three crops will be assessed in terms of carbon sequestration, surface energy and water balance and their spatial variability. This study will help to quantify the importance of various environmental aspects towards modeling bioenergy crops and to better understand the spatial and temporal dynamics of bioenergy crop yields.

  20. Energy Policy Decision-Making: The Need for Balanced Input

    ERIC Educational Resources Information Center

    DeVolpi, A.

    1974-01-01

    Indicates that the credibility of environmentalists and nuclear advocates has been damaged by misinformed alarmist positions. Advocates the public's right of equal standing on advisory councils in the areas of energy development, environmental protection, and public safety. (GS)

  1. Two source energy balance model:Refinements and lysimeter tests in the Southern High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A thermal two-source energy balance model (TSM) was evaluated for predicting daily evapotranspiration (ET) of alfalfa, corn, cotton, grain sorghum, soybean, and wheat in a semiarid, advective environment. Crop ET was measured with large, monolythic weighing lysimeters. The TSM solved the energy budg...

  2. Two source energy balance model-refinements and lysimeter tests in the Southern High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A thermal two-source energy balance model (TSM) was evaluated for predicting daily evapotranspiration (ET) of alfalfa, corn, cotton, grain sorghum, soybean, and wheat in a semiarid, advective environment. Crop ET was measured with large, monolythic weighing lysimeters. The TSM solved the energy budg...

  3. Relations between environmental conditions and the ability to close the energy balance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Any estimates of the transport of mass and energy at the surface must be analyzed to assess reliability and accuracy. A direct approach to this issue is problematic with eddy covariance measurements. However, one approach that offers a measure of self-consistency is to examine the energy balance clo...

  4. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model

    USGS Publications Warehouse

    Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.

    2012-01-01

    We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.

  5. Evaporation and the mass and energy balances of the Dead Sea (Invited)

    NASA Astrophysics Data System (ADS)

    Lensky, N.; Gavrieli, I.; Gertman, I.; Nehorai, R.; Lensky, I. M.; Lyakhovsky, V.; Dvorkin, Y.

    2009-12-01

    The Dead Sea is a hypersaline terminal lake experiencing a water level drop of about 1 m/yr over the last decade. The existing estimations for the water balance of the lake are widely variable, reflecting the unknown subsurface water inflow, the rate of evaporation, and the rate of salt accumulation at the lake bottom. To estimate these we calculate the energy and mass balances for the Dead Sea utilizing measured meteorological and hydrographical data from 1996 to 2009. The data is measured from a buoy located in the Dead Sea 5, km from the nearest shore. The data includes solar radiation (incoming), long wave radiation (downward and upward looking), wind velocity, relative humidity, air temperature, air pressure and water temperature profile. Using energy balance we calculate the evaporation rate, taking into account the impact of lowered surface water activity. From mass balance considerations we calculate the salt precipitation rate, which was about 0.1 m/yr during this period. Using an overall mass balance we get the relation between water inflows, which are the least constrained quantity, and the evaporation rate. The average annual inflow is 265-325 mcm/yr, corresponding to an evaporation rate of 1.1-1.2 m/yr. Higher inflows, suggested in previous studies, call for increased evaporation rate and are therefore not in line with the energy balance. We also take into account the spatial variations and discuss how well the data measured in the buoy represent the Dead Sea surface conditions.

  6. Energy balanced strategies for maximizing the lifetime of sparsely deployed underwater acoustic sensor networks.

    PubMed

    Luo, Hanjiang; Guo, Zhongwen; Wu, Kaishun; Hong, Feng; Feng, Yuan

    2009-01-01

    Underwater acoustic sensor networks (UWA-SNs) are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. Due to economics and the large area of the ocean, UWA-SNs are mainly sparsely deployed networks nowadays. The limited battery resources is a big challenge for the deployment of such long-term sensor networks. Unbalanced battery energy consumption will lead to early energy depletion of nodes, which partitions the whole networks and impairs the integrity of the monitoring datasets or even results in the collapse of the entire networks. On the contrary, balanced energy dissipation of nodes can prolong the lifetime of such networks. In this paper, we focus on the energy balance dissipation problem of two types of sparsely deployed UWA-SNs: underwater moored monitoring systems and sparsely deployed two-dimensional UWA-SNs. We first analyze the reasons of unbalanced energy consumption in such networks, then we propose two energy balanced strategies to maximize the lifetime of networks both in shallow and deep water. Finally, we evaluate our methods by simulations and the results show that the two strategies can achieve balanced energy consumption per node while at the same time prolong the networks lifetime. PMID:22399970

  7. Prediction of energy expenditure from heart rate and accelerometry in children and adolescents using multivariate adaptive regression splines modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Free-living measurements of 24-h total energy expenditure (TEE) and activity energy expenditure (AEE) are required to better understand the metabolic, physiological, behavioral, and environmental factors affecting energy balance and contributing to the global epidemic of childhood obesity. The spec...

  8. Saving Energy in Historic Buildings: Balancing Efficiency and Value

    ERIC Educational Resources Information Center

    Cluver, John H.; Randall, Brad

    2012-01-01

    By now the slogan of the National Trust for Historic Preservation that "the greenest building is the one already built" is widely known. In an era of increased environmental awareness and rising fuel prices, however, the question is how can historic building stock be made more energy efficient in a manner respectful of its historic integrity and…

  9. The Tidal Dynamics and Energy Balance of the Red Sea

    NASA Astrophysics Data System (ADS)

    Pugh, David T.; Abualnaja, Yasser O.; NP, Mohammedali; Eltaib, Elfatih B.

    2014-05-01

    The semidiurnal tides of the Red Sea have been mapped as a classic half-wavelength standing wave. Because of the earth's rotation, the pattern is actually composed of an ingoing Kelvin wave, with maximum amplitude found in the northern eastern side along the Saudi Arabia coastline, and a reflected south-going Kelvin wave along the southern African coastline. The result is tidal rotation around a central amphidrome; this amphidrome, because of energy losses in the reflected wave, is nearer to the African side close to Port Sudan. The movements of this amphidrome can be mapped through a spring-neap tidal cycle to show how the tidal energy is dissipated through the Red Sea. There are suggestions that that Red Sea tides are entirely due to direct internal tidal gravitational astronomical forcing; this is an alternative to the model of energy flux from the Gulf of Aden tides in the Indian Ocean, through the entrance at Bab el Mandeb. These alternative energy sources will be investigated in the project.

  10. Effect of row orientation on energy balance components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solar irradiance is the primary source of energy that is converted into sensible and latent heat fluxes in the soil-plant-atmosphere continuum. The orientation of agricultural crop rows relative to the sun’s zenith angle determines the amount of solar irradiance reaching the plant and soil surfaces...