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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. 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

  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. 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

  1. 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

  2. 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…

  3. 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.

  4. 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.

  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. 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

  9. 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

  10. 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

  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. 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.

  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. 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

  18. 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

  19. 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.

  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. 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.

  5. 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)

  6. 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...

  7. 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

  8. 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.

  9. 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…

  10. 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

  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. 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...

  10. 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…

  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. 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.

  17. 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.

  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. 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.

  7. 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.

  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. 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

  16. 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.

  17. 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...

  18. 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.

  19. [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

  20. 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

  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. 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

  7. 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

  8. 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

  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. 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

  11. 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

  12. 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.

  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. 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

  17. 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.

  18. 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).

  19. 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...

  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. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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)

  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. 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

  11. 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

  12. 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

  13. 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.

  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 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.

  18. 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

  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. 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

  2. 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.

  3. 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 ...

  4. 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...

  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. 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

  8. 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.

  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. 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...

  17. 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...

  18. 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 ...

  19. 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...

  20. 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

  1. 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, ...

  2. 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

  3. 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.

  4. 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

  5. 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

  6. [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

  7. 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

  8. 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

  9. 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

  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. 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

  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. 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.

  15. 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.

  16. 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.

  17. 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

  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. 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.

  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. 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

  8. 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.

  9. 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.

  10. 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).

  11. 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

  12. 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.

  13. [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

  14. 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...

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. [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

  9. 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

  10. 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)

  11. 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)

  12. 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)

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  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. 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...

  3. 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...

  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. 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.

  8. 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...

  9. 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…

  10. The Energy Balance of Corn Ethanol: An Update

    SciTech Connect

    Shapouri, Hosein; Duffield, James A.; Wang, Michael

    2002-07-01

    Studies conducted since the late 1970s have estimated the net energy value (NEV) of corn ethanol. However, variations in data and assumptions used among the studies have resulted in a wide range of estimates. This study identifies the factors causing this wide variation and develops a more consistent estimate.

  11. Energy balance in nanosecond pulse discharges in nitrogen and air

    NASA Astrophysics Data System (ADS)

    Shkurenkov, Ivan; Adamovich, Igor V.

    2016-02-01

    Kinetic modeling is used to analyze energy partition and energy transfer in nanosecond pulse discharges sustained between two spherical electrodes in nitrogen and air. The modeling predictions are compared with previous time-resolved temperature and {{\\text{N}}2}≤ft(X {}1Σ\\text{g}+,v=0-9\\right) vibrational population measurements by picosecond broadband coherent anti-Stokes Raman spectroscopy (CARS) and phase-locked Schlieren imaging. The model shows good agreement with experimental data, reproducing experimental discharge current pulse waveforms, as well as dominant processes of energy transfer in the discharge and the afterglow. Specifically, the results demonstrate that the temperature rise in the plasma occurs in two stages, (i) ‘rapid’ heating on sub-acoustic time scale, dominated by {{\\text{N}}2}≤ft(A {}3Σ\\text{u}+\\right) energy pooling processes, N2(B 3Πg) and N(2P,2D) quenching (in nitrogen), and by quenching of excited electronic states of N2 molecules by O2 (in air), and (ii) ‘slow’ heating due to N2 vibrational relaxation by O atoms (in air), nearly completely missing in nitrogen. Comparison of the model predictions with N2 vibrational level populations confirms that the N2 vibrational temperature rises after the discharge pulse is caused by the ‘downward’ vibrational-vibrational exchange depopulating higher vibrational levels and populating vibrational level v  =  1. The model reproduces temporal dynamics of vibrational level populations and temperature in the discharge and the afterglow, indicating that energy partition among different modes (vibrational, electronic, dissociation, and ionization) is predicted accurately. At the present conditions, energy fraction coupled to the positive column of the discharge filament in air is approximately 50%, with the rest coupled to the cathode layer. Nearly 10% of the total pulse energy is spent on O atom generation, and about 10% is thermalized on a sub-acoustic time scale

  12. On the Balance Energy and Nuclear Dynamics in Peripheral Heavy-Ion Collisions

    NASA Astrophysics Data System (ADS)

    Chugh, Rajiv; Puri, Rajeev K.

    We present here the system size dependence of balance energy for semi-central and peripheral collisions using quantum molecular dynamics model. For this study, the reactions of Ne20+Ne20, Ca40+Ca40, Ni58+ Ni58, Nb93+Nb93, Xe131+Xe131, and Au197+Au197 are simulated at different incident energies and impact parameters. A hard equation of state along with nucleon-nucleon cross-sections between 40 and 55 mb explains the data nicely. Interestingly, balance energy follows a power law ∝Aτ for the mass dependence at all colliding geometries. The power factor τ is close to -(1)/(3) in central collisions, whereas it is -(2)/(3) for peripheral collisions suggesting stronger system size dependence at peripheral geometries. This also suggests that in the absence of momentum dependent interactions, Coulomb's interaction plays an exceedingly significant role. These results are further analyzed for nuclear dynamics at the balance point.

  13. An Analysis of Turbulent Heat Fluxes and the Energy Balance During the REFLEX Campaign

    NASA Astrophysics Data System (ADS)

    Tol, Christiaan van der; Timmermans, Wim; Corbari, Chiara; Carrara, Arnaud; Timmermans, Joris; Su, Zhongbo

    2015-12-01

    Three eddy covariance stations were installed at the Barrax experimental farm during the Land-Atmosphere Exchanges (REFLEX) airborne training and measurement campaign to provide ground truth data of energy balance fluxes and vertical temperature and wind profiles. The energy balance closure ratio (EBR) was 105% for a homogeneous camelina site, 86% at a sparse reforestation site, and 73% for a vineyard. We hypothesize that the lower closure in the last site was related to the limited fetch. Incorporating a vertical gradient of soil thermal properties decreased the RMSE of the energy balance at the camelina site by 16 W m-2. At the camelina site, eddy covariance estimates of sensible and latent heat fluxes could be reproduced well using mean vertical profiles of wind and temperature, provided that the Monin-Obukhov length is known. Measured surface temperature and sensible heat fluxes suggested high excess resistance for heat (kB-1 = 17).

  14. Evaluation of surface energy and radiation balance systems on the Konza Prairie

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.

    1987-01-01

    Four Surface Energy and Radiation Balance Systems (SERBS) were installed and operated for two weeks in Kansas during July of 1986. Surface energy and radiation balances were investigated on six sites on the Konza Prairie about 3 km south of Manhattan, Kansas. Measurements were made to allow the computation of these radiation components: total solar and diffuse radiation, reflected solar radiation, net radiation, and longwave radiation upward and downward. Measurements were made to allow the computation of the sensible and latent heat fluxes by the Bowen ratio method using differential psychrometers on automatic exchange mechanisms. The report includes a description of the experimental sites, data acquisition systems and sensors, data acquisitions system operating instructions, and software used for data acquisition and analysis. In addition, data listings and plots of the energy balance components for all days and systems are given.

  15. Surface-Parallel Sensor Orientation for Assessing Energy Balance Components on Mountain Slopes

    NASA Astrophysics Data System (ADS)

    Serrano-Ortiz, P.; Sánchez-Cañete, E. P.; Olmo, F. J.; Metzger, S.; Pérez-Priego, O.; Carrara, A.; Alados-Arboledas, L.; Kowalski, A. S.

    2016-03-01

    The consistency of eddy-covariance measurements is often evaluated in terms of the degree of energy balance closure. Even over sloping terrain, instrumentation for measuring energy balance components is commonly installed horizontally, i.e. perpendicular to the geo-potential gradient. Subsequently, turbulent fluxes of sensible and latent heat are rotated perpendicular to the mean streamlines using tilt-correction algorithms. However, net radiation (Rn) and soil heat fluxes ( G) are treated differently, and typically only Rn is corrected to account for slope. With an applied case study, we show and argue several advantages of installing sensors surface-parallel to measure surface-normal Rn and G. For a 17 % south-west-facing slope, our results show that horizontal installation results in hysteresis in the energy balance closure and errors of up to 25 %. Finally, we propose an approximation to estimate the surface-normal Rn, when only vertical Rn measurements are available.

  16. 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...

  17. Intraseasonal Variations in Tropical Energy Balance: Relevance to Climate Sensitivity?

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Ramey, Holly S.; Roberts, Jason B.

    2011-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of organization for tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, here we examine the projection of ISOs on the tropically-averaged heat and moisture budget. One unresolved question concerns the degree to which observable variations in the "fast" processes (e.g. convection, radiative / turbulent fluxes) can inform our understanding of feedback mechanisms operable in the context of climate change. Our analysis use daily data from satellite observations, the Modern Era analysis for Research and Applications (MERRA), and other model integrations to address these questions: (i) How are tropospheric temperature variations related to that tropical deep convection and the associated ice cloud fractional amount (ICF), ice water path (IWP), and properties of warmer liquid clouds? (ii) What role does moisture transport play vis-a-vis ocean latent heat flux in enabling the evolution of deep convection to mediate PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007 GRL ) whereby a composite time series of various quantities over 60+ ISO events is built using tropical mean tropospheric temperature signal as a reference to which the variables are related at various lag times (from -30 to +30 days). The area of interest encompasses the global oceans between 20oN/S. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. The decrease in net TOA radiation that develops after the peak in deep convective rainfall, is part of the response that constitutes a "discharge" / "recharge" mechanism that facilitates tropical heat balance

  18. Neuronal energy-sensing pathway promotes energy balance by modulating disease tolerance.

    PubMed

    Shen, Run; Wang, Biao; Giribaldi, Maria G; Ayres, Janelle; Thomas, John B; Montminy, Marc

    2016-06-01

    The starvation-inducible coactivator cAMP response element binding protein (CREB)-cAMP-regulated transcription coactivator (Crtc) has been shown to promote starvation resistance in Drosophila by up-regulating CREB target gene expression in neurons, although the underlying mechanism is unclear. We found that Crtc and its binding partner CREB enhance energy homeostasis by stimulating the expression of short neuropeptide F (sNPF), an ortholog of mammalian neuropeptide Y, which we show here is a direct target of CREB and Crtc. Neuronal sNPF was found to promote energy homeostasis via gut enterocyte sNPF receptors, which appear to maintain gut epithelial integrity. Loss of Crtc-sNPF signaling disrupted epithelial tight junctions, allowing resident gut flora to promote chronic increases in antimicrobial peptide (AMP) gene expression that compromised energy balance. Growth on germ-free food reduced AMP gene expression and rescued starvation sensitivity in Crtc mutant flies. Overexpression of Crtc or sNPF in neurons of wild-type flies dampens the gut immune response and enhances starvation resistance. Our results reveal a previously unidentified tolerance defense strategy involving a brain-gut pathway that maintains homeostasis through its effects on epithelial integrity. PMID:27208092

  19. Integrated energy balance analysis for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Tandler, John

    1991-01-01

    An integrated simulation model is described which characterizes the dynamic interaction of the energy transport subsystems of Space Station Freedom for given orbital conditions and for a given set of power and thermal loads. Subsystems included in the model are the Electric Power System (EPS), the Internal Thermal Control System (ITCS), the External Thermal Control System (ETCS), and the cabin Temperature and Humidity Control System (THC) (which includes the avionics air cooling, cabin air cooling, and intermodule ventilation systems). Models of the subsystems were developed in a number of system-specific modeling tools and validated. The subsystem models are then combined into integrated models to address a number of integrated performance issues involving the ability of the integrated energy transport system of Space Station Freedom to provide power, controlled cabin temperature and humidity, and equipment thermal control to support operations.

  20. Bone and the regulation of global energy balance

    PubMed Central

    Zhang, Qian; Riddle, Ryan C.; Clemens, Thomas L.

    2015-01-01

    The skeleton, populated by large numbers of osteoblasts and long-lived osteocytes, requires a constant supply of energy-rich molecules to fuel the synthesis, deposition, and mineralization of bone matrix during bone modeling and remodeling. When these energetic demands are not met, bone acquisition is suppressed. Recent findings suggest that key developmental signals emanating from WNT- low-density lipoprotein-related receptor 5 and Hypoxia-inducible factor pathways impact osteoblast bioenergetics to accommodate the energy requirements for bone cells to fulfill their function. In vivo studies in several mutant mouse strains have confirmed a link between bone cells and global metabolism, ultimately leading to the identification of hormonal interactions between the skeleton and other tissues. The hormones insulin and leptin affect postnatal bone acquisition, while osteocalcin produced by the osteoblast in turn stimulates insulin secretion by the pancreas. These observations have prompted additional questions regarding the nature of the mechanisms of fuel sensing and processing in the osteoblast and their contribution to overall energy utilization and homeostasis. Answers to such questions should advance our understanding of metabolic diseases and may ultimately improve management of affected patients. In this review we highlight recent studies in this field and offer a perspective on the evolutionary implications of bone as a metabolic endocrine organ. PMID:25597336

  1. National Assessment of Energy Storage for Grid Balancing and Arbitrage: Phase 1, WECC

    SciTech Connect

    Kintner-Meyer, Michael CW; Balducci, Patrick J.; Colella, Whitney G.; Elizondo, Marcelo A.; Jin, Chunlian; Nguyen, Tony B.; Viswanathan, Vilayanur V.; Zhang, Yu

    2012-06-01

    To examine the role that energy storage could play in mitigating the impacts of the stochastic variability of wind generation on regional grid operation, the Pacific Northwest National Laboratory (PNNL) examined a hypothetical 2020 grid scenario in which additional wind generation capacity is built to meet renewable portfolio standard targets in the Western Interconnection. PNNL developed a stochastic model for estimating the balancing requirements using historical wind statistics and forecasting error, a detailed engineering model to analyze the dispatch of energy storage and fast-ramping generation devices for estimating size requirements of energy storage and generation systems for meeting new balancing requirements, and financial models for estimating the life-cycle cost of storage and generation systems in addressing the future balancing requirements for sub-regions in the Western Interconnection. Evaluated technologies include combustion turbines, sodium sulfur (Na-S) batteries, lithium ion batteries, pumped-hydro energy storage, compressed air energy storage, flywheels, redox flow batteries, and demand response. Distinct power and energy capacity requirements were estimated for each technology option, and battery size was optimized to minimize costs. Modeling results indicate that in a future power grid with high-penetration of renewables, the most cost competitive technologies for meeting balancing requirements include Na-S batteries and flywheels.

  2. Atomic Oxygen and Energy Balance in the Mesosphere and Lower Thermosphere

    NASA Astrophysics Data System (ADS)

    Mlynczak, M. G.; Hunt, L. A.; Marshall, T.; Mertens, C. J.; Russell, J. M.; Mast, J. C.; Thompson, R. E.

    2012-12-01

    We use atomic oxygen concentrations measured by SABER in conjunction with measurements of infrared radiative cooling and solar heating to assess the energy balance in the Earth's mesosphere and lower thermosphere. Atomic oxygen plays a central role, particularly in the mesopause region, through heating due to exothermic chemical reactions. The SABER data reveal approximate balance in global heating and cooling on annual timescales. In the 11-year SABER record there is also clear evidence of the solar cycle variation in all of the heat budget terms including atomic oxygen. Long-term changes in heating and cooling rates appear consistent with each other. Uncertainty in the energy budget is due largely to uncertainty in recombination rate coefficients governing exothermic chemical reactions at mesospheric temperatures. In this talk we will show the multitude of energy budget terms derived from SABER observations, the global energy budget, the variability due to the solar cycle, and the uncertainty in the energy balance. We also examine the constraints on the global atomic oxygen concentration based on energy balance considerations.

  3. Transitions in the surface energy balance during the life cycle of a monsoon season

    NASA Astrophysics Data System (ADS)

    Krishnamurti, T. N.; Biswas, Mrinal K.

    2006-04-01

    In this observational/diagnostic study, we illustrate the time history of some important parameters of the surface energy balance during the life cycle of a single monsoon season. This chronology of the surface energy balance portrays the differential equilibrium state from the preonset phase to the withdrawal phase. This includes an analysis of the time history of base variables such as soil moisture, ground temperature, cloud cover, precipitation and humidity. This is followed by an analysis of the components of the surface energy balance where we note subtle changes in the overall balances as we proceed from one epoch of the monsoon to the next. Of interest here is the transition sequence: preonset, onset, break, revival, break, revival and withdrawal during the year 2001. Computations are all illustrated for a box over central India where the coastal effects were small, data coverage was not sparse and where the semi-arid land mass changes drastically to a lush green area. This region exhibited large changes in the components of surface energy balance. The principal results pertain to what balances the difference among the incoming short wave radiation (at the earth’s surface) and the long wave radiation exhibited by the ground. That difference is balanced by a dominant sensible heat flux and the reflected short wave radiation in the preonset stage. A sudden change in the Bowen ratio going from>1 to <1 is noted soon after the onset of monsoon. Thereafter the latent heat flux from the land surface takes an important role and the sensible heat flux acquires a diminishing role. We also examine the subtle changes that occur in the components of surface energy balance between the break and the active phases. The break phases are seen to be quite different from the preonset phases. This study is aimed to illustrate the major importance of moisture and clouds in the radiative transfer computations that are central to the surface energy balance during each epoch

  4. Effects of buffer size and shape on associations between the built environment and energy balance.

    PubMed

    James, Peter; Berrigan, David; Hart, Jaime E; Hipp, J Aaron; Hoehner, Christine M; Kerr, Jacqueline; Major, Jacqueline M; Oka, Masayoshi; Laden, Francine

    2014-05-01

    Uncertainty in the relevant spatial context may drive heterogeneity in findings on the built environment and energy balance. To estimate the effect of this uncertainty, we conducted a sensitivity analysis defining intersection and business densities and counts within different buffer sizes and shapes on associations with self-reported walking and body mass index. Linear regression results indicated that the scale and shape of buffers influenced study results and may partly explain the inconsistent findings in the built environment and energy balance literature. PMID:24607875

  5. Effects of Buffer Size and Shape on Associations between the Built Environment and Energy Balance

    PubMed Central

    Berrigan, David; Hart, Jaime E.; Hipp, J. Aaron; Hoehner, Christine M.; Kerr, Jacqueline; Major, Jacqueline M.; Oka, Masayoshi; Laden, Francine

    2014-01-01

    Uncertainty in the relevant spatial context may drive heterogeneity in findings on the built environment and energy balance. To estimate the effect of this uncertainty, we conducted a sensitivity analysis defining intersection and business densities and counts within different buffer sizes and shapes on associations with self-reported walking and body mass index. Linear regression results indicated that the scale and shape of buffers influenced study results and may partly explain the inconsistent findings in the built environment and energy balance literature. PMID:24607875

  6. [Role of brain lipid sensing in nervous regulation of energy balance].

    PubMed

    Moullé, Valentine S; Picard, Alexandre; Cansell, Céline; Luquet, Serge; Magnan, Christophe

    2015-04-01

    Fatty acid sensitive neurons located in hypothalamus, hippocampus or striatum are able to detect daily variations of plasma fatty acid levels. Thus, these neurons play a role to regulate energy balance by controling food intake, insulin secretion or hepatic glucose production. Molecular mechanisms that mediate fatty acid effects include receptor FAT (fatty acid transporter)/CD36. Deregulation of this brain lipid sensing may be an early event leading to further dysfunction of energy balance leading to obesity and type 2 diabetes. PMID:25958758

  7. Minimizing Wind Power Producer's Balancing Costs Using Electrochemical Energy Storage: Preprint

    SciTech Connect

    Miettinen, J.; Tikka, V.; Lassila, J.; Partanen, J.; Hodge, B. M.

    2014-08-01

    This paper examines how electrochemical energy storage can be used to decrease the balancing costs of a wind power producer in the Nordic market. Because electrochemical energy storage is developing in both technological and financial terms, a sensitivity analysis was carried out for the most important variables in the wind-storage hybrid system. The system was studied from a wind power producer's point of view. The main result is that there are no technical limitations to using storage for reducing the balancing costs. However, in terms of economic feasibility, installing hybrid wind-storage systems such as the one studied in this paper faces challenges in both the short and long terms.

  8. Evaluation of a two source snow-vegetation energy balance model for estimating surface energy fluxes in a rangeland ecosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The utility of a two source snow-vegetation energy balance model for estimating surface energy fluxes is evaluated with field measurements at two sites in a rangeland ecosystem in southwestern Idaho during the winter of 2007: one site dominated by aspen vegetation and the other by sagebrush. Model ...

  9. Association Between Estimated 24-h Urinary Sodium Excretion and Metabolic Syndrome in Korean Adults

    PubMed Central

    Won, Jong Chul; Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

    2016-01-01

    Abstract High sodium intake is 1 of the modifiable risk factors for cardiovascular disease, but in Korea, daily sodium intake is estimated to be double the level recommended by World Health Organization. We investigated the association between the estimated 24-h urinary sodium excretion (24hUNaE) and metabolic syndrome using nationwide population data. In total, 17,541 individuals (weighted n = 33,200,054; weighted men, 52.5% [95% confidence interval, CI = 51.8–53.3]; weighted age, 45.2 years [44.7–45.7]) who participated in the Korean Health and Nutrition Examination Survey 2009 to 2011 were investigated. NCEP-ATP III criteria for metabolic syndrome were used, and sodium intake was estimated by 24hUNaE using Tanaka equation with a spot urine sample. The weighted mean 24hUNaE values were 3964 mg/d (95% CI = 3885–4044) in men and 4736 mg/d (4654–4817) in women. The weighted age-adjusted prevalence of metabolic syndrome was 22.2% (21.4–23.0), and it increased with 24hUNaE quartile in both men and women (mean ± standard error of the mean; men: 22.5 ± 1.0%, 23.0 ± 1.0%, 26.0 ± 1.2%, and 26.0 ± 1.2%; P = 0.026; women: 19.4 ± 0.8%, 17.7 ± 0.8%, 19.8 ± 1.0%, and 23.0 ± 1.1%; P = 0.002, for quartiles 1–4, respectively). Even after adjustment for age, daily calorie intake, heavy alcohol drinking, regular exercise, college graduation, and antihypertensive medication, the weighted prevalence of metabolic syndrome increased with the increase in 24hUNaE in men and women. The weighted 24hUNaE was positively associated with the number of metabolic syndrome components after adjustment for confounding factors in men and women. In subjects without antihypertensive medication, the odds ratio for metabolic syndrome in quartile 4 of 24hUNaE compared with quartile 1 was 1.56 (1.33–1.84, P < 0.001) in the total population, 1.66 (1.34–2.06, P < 0.001) in men, and 1.94 (1.49–2.53, P < 0

  10. Food and physical activity environments: an energy balance approach for research and practice.

    PubMed

    Economos, Christina D; Hatfield, Daniel P; King, Abby C; Ayala, Guadalupe X; Ann Pentz, Mary

    2015-05-01

    Increases in the prevalence of overweight and obesity are a function of chronic, population-level energy imbalance, whereby energy intakes exceed energy expenditures. Although sometimes viewed in isolation, energy intakes and expenditures in fact exist in a dynamic interplay: energy intakes may influence energy expenditures and vice versa. Obesogenic environments that promote positive energy balance play a central role in the obesity epidemic, and reducing obesity prevalence will require re-engineering environments to promote both healthy eating and physical activity. There may be untapped synergies in addressing both sides of the energy balance equation in environmentally focused obesity interventions, yet food/beverage and physical activity environments are often addressed separately. The field needs design, evaluation, and analytic methods that support this approach. This paper provides a rationale for an energy balance approach and reviews and describes research and practitioner work that has taken this approach to obesity prevention at the environmental and policy levels. Future directions in research, practice, and policy include moving obesity prevention toward a systems approach that brings both nutrition and physical activity into interdisciplinary training, funding mechanisms, and clinical and policy recommendations/guidelines. PMID:25891062

  11. Obesity as malnutrition: the dimensions beyond energy balance.

    PubMed

    Wells, J C K

    2013-05-01

    The aetiology of obesity is seemingly simple to understand: individuals consume more energy than they expend, with the excess energy being stored in adipose tissue. Public health campaigns therefore promote dietary restraint and physical exercise, and emphasize individual responsibility for these behaviours. Increasingly, however, researchers are switching from thermodynamic to metabolic models of obesity, thereby clarifying how specific environmental factors promote lipogenesis. Obesity can best be explained not by counting 'calories in and out', but by understanding how specific dietary products and activity behaviours perturb cellular metabolism and promote net lipogenesis. This metabolic approach can furthermore be integrated with more sophisticated models of how commercial practices drive the consumer trends that promote obesogenic behaviours. Notably, obesity treatment has proven more effective if it bypasses individual responsibility, suggesting that a similar approach placing less emphasis on individual responsibility would improve the efficacy of obesity prevention. Successful obesity prevention campaigns are likely to emerge only when the public receive better 'protection' from the commercial practices that are driving the global obesity epidemic. Rather than populations failing to heed governments' public health advice, governments are currently failing the public by abandoning their responsibility for regulating commercial activities. PMID:23443827

  12. Brain lipid sensing and the neural control of energy balance.

    PubMed

    Magnan, Christophe; Levin, Barry E; Luquet, Serge

    2015-12-15

    Fatty acid (FA) -sensitive neurons are present in the brain, especially the hypothalamus, and play a key role in the neural control of energy and glucose homeostasis including feeding behavior, secretion insulin and action. Subpopulations of neurons in the arcuate and ventromedial hypothalamic nuclei are selectively either activated or inhibited by FA. Molecular effectors of these FA effects include ion channels such as chloride, potassium or calcium. In addition, at least half of the responses in the hypothalamic ventromedial FA neurons are mediated through interaction with the FA translocator/receptor, FAT/CD36, that does not require metabolism to activate intracellular signaling downstream. Recently, an important role of lipoprotein lipase in FA detection has also been demonstrated not only in the hypothalamus, but also in the hippocampus and striatum. Finally, FA could overload energy homeostasis via increased hypothalamic ceramide synthesis which could, in turn, contribute to the pathogenesis of diabetes of obesity and/or type 2 in predisposed individuals by disrupting the endocrine signaling pathways of insulin and/or leptin. PMID:26415589

  13. Cloud Impacts on Pavement Temperature in Energy Balance Models

    NASA Astrophysics Data System (ADS)

    Walker, C. L.

    2013-12-01

    Forecast systems provide decision support for end-users ranging from the solar energy industry to municipalities concerned with road safety. Pavement temperature is an important variable when considering vehicle response to various weather conditions. A complex, yet direct relationship exists between tire and pavement temperatures. Literature has shown that as tire temperature increases, friction decreases which affects vehicle performance. Many forecast systems suffer from inaccurate radiation forecasts resulting in part from the inability to model different types of clouds and their influence on radiation. This research focused on forecast improvement by determining how cloud type impacts the amount of shortwave radiation reaching the surface and subsequent pavement temperatures. The study region was the Great Plains where surface solar radiation data were obtained from the High Plains Regional Climate Center's Automated Weather Data Network stations. Road pavement temperature data were obtained from the Meteorological Assimilation Data Ingest System. Cloud properties and radiative transfer quantities were obtained from the Clouds and Earth's Radiant Energy System mission via Aqua and Terra Moderate Resolution Imaging Spectroradiometer satellite products. An additional cloud data set was incorporated from the Naval Research Laboratory Cloud Classification algorithm. Statistical analyses using a modified nearest neighbor approach were first performed relating shortwave radiation variability with road pavement temperature fluctuations. Then statistical associations were determined between the shortwave radiation and cloud property data sets. Preliminary results suggest that substantial pavement forecasting improvement is possible with the inclusion of cloud-specific information. Future model sensitivity testing seeks to quantify the magnitude of forecast improvement.

  14. Chloroplast quality control - balancing energy production and stress.

    PubMed

    Woodson, Jesse D

    2016-10-01

    Contents 36 I. 36 II. 37 III. 37 IV. 38 V. 39 VI. 40 VII. 40 40 References 40 SUMMARY: All organisms require the ability to sense their surroundings and adapt. Such capabilities allow them to thrive in a wide range of habitats. This is especially true for plants, which are sessile and have to be genetically equipped to withstand every change in their environment. Plants and other eukaryotes use their energy-producing organelles (i.e. mitochondria and chloroplasts) as such sensors. In response to a changing cellular or external environment, these organelles can emit 'retrograde' signals that alter gene expression and/or cell physiology. This signaling is important in plants, fungi, and animals and impacts diverse cellular functions including photosynthesis, energy production/storage, stress responses, growth, cell death, ageing, and tumor progression. Originally, chloroplast retrograde signals in plants were known to lead to the reprogramming of nuclear transcription. New research, however, has pointed to additional posttranslational mechanisms that lead to chloroplast regulation and turnover in response to stress. Such mechanisms involve singlet oxygen, ubiquitination, the 26S proteasome, and cellular degradation machinery. PMID:27533783

  15. Nqrs Data for C24H20MnO4P (Subst. No. 1581)

    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 C24H20MnO4P (Subst. No. 1581)

  16. Association of estimated glomerular filtration rate with 24-h urinalysis and stone composition.

    PubMed

    Moreira, Daniel M; Friedlander, Justin I; Hartman, Christopher; Gershman, Boris; Smith, Arthur D; Okeke, Zeph

    2016-08-01

    The aim of this study is to determine the association of estimated glomerular filtration rate (eGFR) with 24-h urine analysis and stone composition. We performed a retrospective review of 1060 stone formers with 24-h urinalysis, of which 499 had stone composition analysis available. Comparisons of baseline patient characteristics and urinary abnormalities across eGFR groups (<60, 60-89.9, ≥90 mL/min/1.73 m(2)) were performed using Fisher's exact test for categorical data and analysis of variance for continuous variables. Analyses of 24-h urinalysis and stone composition across eGFR groups were performed using linear regression with eGFR groups as a continuous variable to evaluate trends. Of the 1060 patients in the study, 595 (56 %) were males. The mean age was 53.8 years. A total of 38 (4 %), 77 (7 %), and 945 (89 %) patients had eGFR <60, 60-89.9, and ≥90 mL/min/1.73 m(2), respectively. Lower eGFR was associated with older age, lower body-mass index, and female gender (all P < 0.05). Lower eGFR was also associated with lower urinary volume, calcium, citrate, uric acid, sodium, magnesium, phosphorus, sulfate, and creatinine on both univariable and multivariable analyses, adjusted for demographics, comorbidities and medication use (all P < 0.05). The prevalence of hypocitraturia and hypomagnesuria was associated with decreased eGFR, while hypercalciuria, hyperoxaluria, hyperuricosuria and hyperphosphaturia were associated with higher eGFR (all P < 0.05). Stone composition was similar across eGFR groups (all P > 0.05). In conclusion, lower eGFR was associated with lower excretion of urinary elements in a routine 24-h urinalysis, but similar stone composition. PMID:26573808

  17. Ovine platelet function is unaffected by extracorporeal membrane oxygenation within the first 24 h.

    PubMed

    Hayes, Rylan A; Foley, Samuel; Shekar, Kiran; Diab, Sara; Dunster, Kimble R; McDonald, Charles; Fraser, John F

    2015-10-01

    This study investigated platelet dysfunction during short-term extracorporeal membrane oxygenation (ECMO) and secondarily to determine if hyperoxaemia contributes to this dysfunction. Healthy sheep were anaesthetized and maintained on ECMO for either 2 or 24 h, with or without induction of smoke inhalation acute lung injury. A specialized animal-operating theatre was used to conduct the experimentation. Forty-three healthy female sheep were randomized into either a test or a control group. Following anaesthesia, test groups received ECMO ± smoke inhalation acute lung injury (SALI), whereas control groups were maintained with ventilation only ± SALI. Physiological, biochemical and coagulation data were obtained throughout via continuous monitoring and blood sampling. Platelet function was quantified through whole blood impedance aggregometry using Multiplate. Ovine platelet activity induced by adenosine diphosphate (ADP) and collagen was unaffected during the first 24 h of ECMO. However, progressive divergence of ADP-induced platelet activity was noted at cessation of the experiment. PaO2 was inversely related to ADP-dependent platelet activity in the ECMO groups--a relationship not identified in the control groups. ADP and collagen-dependent platelet activity are not significantly affected within the first 24 h of ECMO in sheep. However, dysfunction in ADP-dependent platelet activity may have continued to develop if observed beyond 24 h. Hyperoxaemia during ECMO does appear to affect how platelets react to ADP and may contribute to this developing dysfunction. Long-term animal models and investigation in clinical animals are warranted to fully investigate platelet function during ECMO. PMID:26196193

  18. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults.

    PubMed

    Mamerow, Madonna M; Mettler, Joni A; English, Kirk L; Casperson, Shanon L; Arentson-Lantz, Emily; Sheffield-Moore, Melinda; Layman, Donald K; Paddon-Jones, Douglas

    2014-06-01

    The RDA for protein describes the quantity that should be consumed daily to meet population needs and to prevent deficiency. Protein consumption in many countries exceeds the RDA; however, intake is often skewed toward the evening meal, whereas breakfast is typically carbohydrate rich and low in protein. We examined the effects of protein distribution on 24-h skeletal muscle protein synthesis in healthy adult men and women (n = 8; age: 36.9 ± 3.1 y; BMI: 25.7 ± 0.8 kg/m2). By using a 7-d crossover feeding design with a 30-d washout period, we measured changes in muscle protein synthesis in response to isoenergetic and isonitrogenous diets with protein at breakfast, lunch, and dinner distributed evenly (EVEN; 31.5 ± 1.3, 29.9 ± 1.6, and 32.7 ± 1.6 g protein, respectively) or skewed (SKEW; 10.7 ± 0.8, 16.0 ± 0.5, and 63.4 ± 3.7 g protein, respectively). Over 24-h periods on days 1 and 7, venous blood samples and vastus lateralis muscle biopsy samples were obtained during primed (2.0 μmol/kg) constant infusion [0.06 μmol/(kg⋅min)] of l-[ring-(13)C6]phenylalanine. The 24-h mixed muscle protein fractional synthesis rate was 25% higher in the EVEN (0.075 ± 0.006%/h) vs. the SKEW (0.056 ± 0.006%/h) protein distribution groups (P = 0.003). This pattern was maintained after 7 d of habituation to each diet (EVEN vs. SKEW: 0.077 ± 0.006 vs. 0.056 ± 0.006%/h; P = 0.001). The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal. PMID:24477298

  19. Nqrs Data for C24H42Li2N4 (Subst. No. 1587)

    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 C24H42Li2N4 (Subst. No. 1587)

  20. Mass and energy balance constraints on the biological production of chemicals from coal

    SciTech Connect

    Andrews, G.

    1990-01-01

    Several organic chemicals, including methane and ethanol, may be produced by the bioprocessing of coal. This may be done either by direct microbial attack on the coal, or indirectly by the bioprocessing of solubilized coal. As in chemical liquefaction and gasification, the relative amounts of the various products that can be produced are severely constrained by mass and energy balance considerations. The main differences in biological processing are that water is a ubiquitous reactant, carbon dioxide a common product, and that some of the carbon and nitrogen in the coal may go to the synthesis of new biomass rather than products. The conventional biotechnological yield analysis applied to coal processing has several interesting consequences. The mass balance reduces to a balance of available electrons, and coal has a similar oxidation/reduction state to both carbohydrates and biomass. This makes high product yields feasible particularly under anaerobic conditions, although leaving open the question of whether the relevant hydrolase enzymes exist. Recommendations are made on products, and combinations of two products, that may be made with high yields and economic return. The energy balance provides little extra information. A general intracellular energy balance can be written in terms of the production and consumption of ATP, but much of the necessary information on the metabolic pathways is currently not available for coal processing microorganisms. 9 refs., 2 figs., 2 tabs.

  1. Development of a UK Online 24-h Dietary Assessment Tool: myfood24

    PubMed Central

    Carter, Michelle C.; Albar, Salwa A.; Morris, Michelle A.; Mulla, Umme Z.; Hancock, Neil; Evans, Charlotte E.; Alwan, Nisreen A.; Greenwood, Darren C.; Hardie, Laura J.; Frost, Gary S.; Wark, Petra A.; Cade, Janet E.

    2015-01-01

    Assessment of diet in large epidemiological studies can be costly and time consuming. An automated dietary assessment system could potentially reduce researcher burden by automatically coding food records. myfood24 (Measure Your Food on One Day) an online 24-h dietary assessment tool (with the flexibility to be used for multiple 24 h-dietary recalls or as a food diary), has been developed for use in the UK population. Development of myfood24 was a multi-stage process. Focus groups conducted with three age groups, adolescents (11–18 years) (n = 28), adults (19–64 years) (n = 24) and older adults (≥65 years) (n = 5) informed the development of the tool, and usability testing was conducted with beta (adolescents n = 14, adults n = 8, older adults n = 1) and live (adolescents n = 70, adults n = 20, older adults n = 4) versions. Median system usability scale (SUS) scores (measured on a scale of 0–100) in adolescents and adults were marginal for the beta version (adolescents median SUS = 66, interquartile range (IQR) = 20; adults median SUS = 68, IQR = 40) and good for the live version (adolescents median SUS = 73, IQR = 22; adults median SUS = 80, IQR = 25). Myfood24 is the first online 24-h dietary recall tool for use with different age groups in the UK. Usability testing indicates that myfood24 is suitable for use in UK adolescents and adults. PMID:26024292

  2. Immune cell changes in response to a swimming training session during a 24-h recovery period.

    PubMed

    Morgado, José P; Monteiro, Cristina P; Teles, Júlia; Reis, Joana F; Matias, Catarina; Seixas, Maria T; Alvim, Marta G; Bourbon, Mafalda; Laires, Maria J; Alves, Francisco

    2016-05-01

    Understanding the impact of training sessions on the immune response is crucial for the adequate periodization of training, to prevent both a negative influence on health and a performance impairment of the athlete. This study evaluated acute systemic immune cell changes in response to an actual swimming session, during a 24-h recovery period, controlling for sex, menstrual cycle phases, maturity, and age group. Competitive swimmers (30 females, 15 ± 1.3 years old; and 35 males, 16.5 ± 2.1 years old) performed a high-intensity training session. Blood samples were collected before, immediately after, 2 h after, and 24 h after exercise. Standard procedures for the assessment of leukogram by automated counting (Coulter LH 750, Beckman) and lymphocytes subsets by flow cytometry (FACS Calibur BD, Biosciences) were used. Subjects were grouped according to competitive age groups and pubertal Tanner stages. Menstrual cycle phase was monitored. The training session induced neutrophilia, lymphopenia, and a low eosinophil count, lasting for at least 2 h, independent of sex and maturity. At 24 h postexercise, the acquired immunity of juniors (15-17 years old), expressed by total lymphocytes and total T lymphocytes (CD3(+)), was not fully recovered. This should be accounted for when planning a weekly training program. The observed lymphopenia suggests a lower immune surveillance at the end of the session that may depress the immunity of athletes, highlighting the need for extra care when athletes are exposed to aggressive environmental agents such as swimming pools. PMID:27028294

  3. Energy balance and turbulent flux partitioning in a corn-soybean rotation in the Midwestern US

    NASA Astrophysics Data System (ADS)

    Hernandez-Ramirez, Guillermo; Hatfield, Jerry L.; Prueger, John H.; Sauer, Thomas J.

    2010-03-01

    Quantifying the energy balance above plant canopies is critical for better understanding of water balance and changes in regional weather patterns. This study examined temporal variations of energy balance terms for contrasting canopies [corn ( Zea mays L.) and soybean ( Glycine max L. Merr.)]. We monitored energy balance for 4 years using eddy-covariance systems, net radiometers, and soil heat flux plates in adjacent production fields near Ames, Iowa. On an annual basis, soybean exhibited 20% and 30% lower sensible heat flux ( H) and Bowen ratio than corn, respectively. As canopies developed, a gradual shift in turbulent fluxes occurred with decreasing H and increasing latent heat flux (LE), but with a more pronounced effect for corn. Conversely, during mid-growing season and as both canopies progressively senesced, H in general increased and LE decreased; however, soybean exhibited slightly greater LE and much lower H than corn. These temporal variations in magnitude and partitioning of turbulent fluxes translated into a pronounced energy imbalance for soybean (0.80) and an enhanced closure for corn (0.98) in August and September. These discrepancies could be directly associated with differences in momentum transport as shown by friction velocities of 0.34 and 0.28 m s-1 for corn and soybean, respectively. These results support influential roles of plant canopy on intensity and mode of surface energy exchange processes.

  4. Surface energy balance and turbulence characteristics observed at the SHEBA Ice Camp during FIRE III

    NASA Astrophysics Data System (ADS)

    Duynkerke, Peter G.; de Roode, Stephan R.

    2001-07-01

    The Institute for Marine and Atmospheric Research Utrecht (IMAU) participated in the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE III) in May 1998. In this paper we describe surface layer measurements performed on the sea ice at the Surface Heat and Energy Balance of the Arctic Ocean (SHEBA) camp and compare these with measurements collected above a grass-covered surface in Cabauw, the Netherlands. The observations consist of both high-frequency turbulence measurements and mean-profile measurements of wind, temperature, and humidity. In addition, we measured the upward and downward components of both the longwave and the shortwave radiation, and the snow and ice temperatures in the upper 40 cm. The observations give a detailed picture of all components of the energy balance of the Arctic sea-ice surface. The turbulence measurements are used to study the surface layer scaling of the turbulence variables in the stable boundary layer. More specifically, we showed that the integral length scale of the vertical velocity fluctuations serves as the relevant turbulence length scale. The monthly averaged energy balance of the Arctic sea-ice was dominated by radiative fluxes, whereas the sensible and latent heat flux and the energy flux into the surface were rather small. A detailed inspection of the diurnal variations in the turbulent fluxes, however, indicates that although the monthly averaged values are small, the hourly averaged values for these fluxes are significant in the surface energy balance.

  5. Energy Balance Regulation and Flexible Production: A New Frontier for Aluminum Smelting

    NASA Astrophysics Data System (ADS)

    Taylor, Mark P.; Etzion, Ron; Lavoie, Pascal; Tang, Jianning

    2014-09-01

    Through a critical review of recent literature on aluminum smelting cell energy balance, this paper defines specific energy constraints which govern the feasibility of cell operation in practice. Using these constraints as a basis, the objective of reducing energy consumption per kilogram of aluminum produced was examined, again with reference to published data and modern cell developments over the last 5 years. Both incremental and quantum steps in cell design are considered in this analysis, in pursuit of a pathway to lower energy consumption in a process where energy efficiency has not yet risen above 50 pct. In Section V and VI of this work, a generic high amperage cell technology is examined using a computational model of the cell energy balance, in which the resultant electrolyte phases and their thermal, electrical, and physical states can be determined. Using a series of trial energy balances, a feasible operating point emerges, and the possibility of flexible cell amperage and production rate is tested in a preliminary way. The specific energy consumption and market implications of this new technology direction are examined.

  6. Energy Balance Regulation and Flexible Production: A New Frontier for Aluminum Smelting

    NASA Astrophysics Data System (ADS)

    Taylor, Mark P.; Etzion, Ron; Lavoie, Pascal; Tang, Jianning

    2014-12-01

    Through a critical review of recent literature on aluminum smelting cell energy balance, this paper defines specific energy constraints which govern the feasibility of cell operation in practice. Using these constraints as a basis, the objective of reducing energy consumption per kilogram of aluminum produced was examined, again with reference to published data and modern cell developments over the last 5 years. Both incremental and quantum steps in cell design are considered in this analysis, in pursuit of a pathway to lower energy consumption in a process where energy efficiency has not yet risen above 50 pct. In Section V and VI of this work, a generic high amperage cell technology is examined using a computational model of the cell energy balance, in which the resultant electrolyte phases and their thermal, electrical, and physical states can be determined. Using a series of trial energy balances, a feasible operating point emerges, and the possibility of flexible cell amperage and production rate is tested in a preliminary way. The specific energy consumption and market implications of this new technology direction are examined.

  7. Heart rate measurements as an index of energy expenditure and energy balance in ruminants: a review.

    PubMed

    Brosh, A

    2007-05-01

    A major part of the ME consumed by ruminants (MEI) is dissipated as heat. This fraction, called heat production or energy expenditure (EE), is assayed largely by measuring O2 consumption (VO2). Conventional measurement of EE in controlled conditions in chambers does not reflect the complexity of natural, environmental, and social conditions of free-ranging animals. In mammals, most of the measured VO2 is transferred to the tissues through the heart; therefore, regression of heart rate (HR) against VO2 can be used to estimate the EE of free-ranging animals. The present article reviews the current knowledge on the use of HR for estimating EE. Energy expenditure can be determined from HR measurements, recorded daily over the course of several days, multiplied by the VO2 per beat. When an animal does not perform significant exercise, a constant value of VO2 per beat [O2 pulse (O2P)] measured over a short period (10 to 15 min) is used; during exercise, O2P increases, and the regression equation of VO2 against HR is used. Under extreme heat load, HR increases to improve heat dissipation, and O2P decreases; therefore, the effect of heat load on O2P needs to be taken into account. Cold stress that doubles heat production does not affect O2P. Heart rate and EE are highly correlated with MEI, but there is significant individual variation in the relationship; therefore, the daily change in the HR of individual animals can be used as an indicator of changes in the individual energy status of a ruminant, and the average HR of the group can serve in the estimation of the energy status of the group. When O2P is measured, the average group EE is an indication of the energy balance of the whole group. Because the MEI of nondraft animals is the sum of EE and retained energy (RE), the MEI of free-ranging ruminants can be determined by measurement of EE by the HR method and adding the RE. Similarly, the RE can be determined without slaughtering the animals from measurements of EE and

  8. 24-h urinary sodium excretion is associated with obesity in a cross-sectional sample of Australian schoolchildren.

    PubMed

    Grimes, Carley A; Riddell, Lynn J; Campbell, Karen J; He, Feng J; Nowson, Caryl A

    2016-03-28

    Emerging evidence indicates that dietary Na may be linked to obesity; however it is unclear whether this relationship is independent of energy intake (EI). The aim of this study was to assess the association between Na intake and measures of adiposity, including BMI z score, weight category and waist:height ratio (WHtR), in a sample of Australian schoolchildren. This was a cross-sectional study of schoolchildren aged 4-12 years. Na intake was assessed via one 24-h urine collection. BMI was converted to age- and sex-specific z scores, and WHtR was used to define abdominal obesity. In children aged ≥8 years, EI was determined via one 24-h dietary recall. Of the 666 children with valid urine samples 55 % were male (average age 9·3 (sd 1·8) years). In adjusted models an additional 17 mmol/d of Na was associated with a 0·10 higher BMI z score (95 % CI 0·07, 0·13), a 23 % (OR 1·23; 95 % CI 1·16, 1·31) greater risk of being overweight/obese and a 15 % (OR 1·15; 95 % CI 1·09, 1·23) greater risk of being centrally obese. In the subsample of 8-12-year-old children (n 458), adjustment for EI did not markedly alter the associations between Na and adiposity outcomes. Using a robust measure of daily Na intake we found a positive association between Na intake and obesity risk in Australian schoolchildren, which could not be explained by total energy consumption. To determine whether this is a causal relationship, longitudinal studies, with high-quality measures of Na and EI, are required. PMID:26810972

  9. Improving the XAJ Model on the Basis of Mass-Energy Balance

    NASA Astrophysics Data System (ADS)

    Fang, Yuanghao; Corbari, Chiara; Zhang, Xingnan; Mancini, Marco

    2014-11-01

    The Xin’anjiang(XAJ) model is a conceptual model developed by the group led by Prof. Ren-Jun Zhao, which takes the pan evaporation as one of its input and then computes the effective evapotranspiration (ET) of the catchment by mass balance. Such scheme can ensure a good performance of discharge simulation but has obvious defects, one of which is that the effective ET is spatially-constant over the computation unit, neglecting the spatial variation of variables that influence the effective ET and therefore the simulation of ET and SM by the XAJ model, comparing with discharge, is less reliable. In this study, The XAJ model was improved to employ both energy and mass balance to compute the ET following the energy-mass balance scheme of FEST-EWB. model.

  10. Evaluation of water and energy balances ovet the Colombian Orinoco Catchment Basin

    NASA Astrophysics Data System (ADS)

    Abril, C.; Baquero-Bernal, A.

    2012-04-01

    This study presents a comparison between in-situ observations and gridded data from reanalyses and from a regional climate model over the Colombian Orinoco Catchment Basin, in South America, with focus on the surface water and energy balances. We use datasets from the regional climate model REMO and re-analyses ERA40, ERAInterim and NCEP/NCAR. The in-situ observations have been provided by the Colombian Institute of Hydrology, Meteorology and Environmental Studies (IDEAM). The balances are for the 1958-2011 period. Statistical analyses of temperature and precipitation are also presented. Discrepancies between gridded datasets and observations are evaluated and possible sources of error in each of the datasets are discussed. The research presented is the first intercomparison of the surface water and energy balances over the Colombian Orinoco Catchment Basin from different datasets.

  11. Regional earth-atmosphere energy balance estimates based on assimilations with a GCM

    NASA Technical Reports Server (NTRS)

    Alexander, Michael A.; Schubert, Siegfried D.

    1990-01-01

    The Oort and Vonder Haar (1976) column-budget technique is presently used to evaluate the physical consistency and accuracy of regional earth-atmosphere energy balance estimates for (1) atmospheric budget terms, (2) net radiation at the top of the atmosphere, and (3) time tendency and flux divergence of energy, for Special Observing Periods of the FGGE year. It is found that, during winter, the midlatitude oceans supply large quantities of energy to the overlying atmosphere, which then transports the energy to the continental heat-sinks; the energy flows in the opposite direction during summer.

  12. Energy balance model of a SOFC cogenerator operated with biogas

    NASA Astrophysics Data System (ADS)

    Van herle, Jan; Maréchal, F.; Leuenberger, S.; Favrat, D.

    A small cogeneration system based on a Solid Oxide Fuel Cell (SOFC) fed on the renewable energy source biogas is presented. An existing farm biogas production site (35 m 3 per day), currently equipped with a SOFC demonstration stack, is taken for reference. A process flow diagram was defined in a software package allowing to vary system operating parameters like the fuel inlet composition, reforming technology, stack temperature and stack current (or fuel conversion). For system reforming simplicity, a base case parameter set was defined as the fuel inlet of 60% CH 4:40% CO 2 mixed with air in a 1:1 ratio, together with 800 °C operating temperature and 80% fuel conversion. A model stack, consisting of 100 series elements of anode supported electrolyte cells of 100 cm 2 each, was calculated to deliver 3.1 kW el and 5.16 kW th from an input of 1.5 N m 3/h of biogas (8.95 kW LHV), corresponding to 33.8 and 57.6% electrical and thermal efficiencies (Lower Heating Values (LHVs)), respectively. The incidence on the efficiencies of the model system was examined by the variation of a number of parameters such as the CO 2 content in the biogas, the amount of air addition to the biogas stream, the addition of steam to the fuel inlet, the air excess ratio λ and the stack operating temperature, and the results discussed.

  13. Dysregulation of energy balance by trichothecene mycotoxins: Mechanisms and prospects.

    PubMed

    Lebrun, Bruno; Tardivel, Catherine; Félix, Bernadette; Abysique, Anne; Troadec, Jean-Denis; Gaigé, Stéphanie; Dallaporta, Michel

    2015-07-01

    Trichothecenes are toxic metabolites produced by fungi that constitute a worldwide hazard for agricultural production and both animal and human health. More than 40 countries have introduced regulations or guidelines for food and feed contamination levels of the most prevalent trichothecene, deoxynivalenol (DON), on the basis of its ability to cause growth suppression. With the development of analytical tools, evaluation of food contamination and exposure revealed that a significant proportion of the human population is chronically exposed to DON doses exceeding the provisional maximum tolerable daily dose. Accordingly, a better understanding of trichothecene impact on health is needed. Upon exposure to low or moderate doses, DON and other trichothecenes induce anorexia, vomiting and reduced weight gain. Several recent studies have addressed the mechanisms by which trichothecenes induce these symptoms and revealed a multifaceted action targeting gut, liver and brain and causing dysregulation in neuroendocrine signaling, immune responses, growth hormone axis, and central neurocircuitries involved in energy homeostasis. Newly identified trichothecene toxicosis biomarkers are just beginning to be exploited and already open up new questions on the potential harmful effects of chronic exposure to DON at apparently asymptomatic very low levels. This review summarizes our current understanding of the effects of DON and other trichothecenes on food intake and weight growth. PMID:25956358

  14. Daily magnesium fluxes regulate cellular timekeeping and energy balance.

    PubMed

    Feeney, Kevin A; Hansen, Louise L; Putker, Marrit; Olivares-Yañez, Consuelo; Day, Jason; Eades, Lorna J; Larrondo, Luis F; Hoyle, Nathaniel P; O'Neill, John S; van Ooijen, Gerben

    2016-04-21

    Circadian clocks are fundamental to the biology of most eukaryotes, coordinating behaviour and physiology to resonate with the environmental cycle of day and night through complex networks of clock-controlled genes. A fundamental knowledge gap exists, however, between circadian gene expression cycles and the biochemical mechanisms that ultimately facilitate circadian regulation of cell biology. Here we report circadian rhythms in the intracellular concentration of magnesium ions, [Mg(2+)]i, which act as a cell-autonomous timekeeping component to determine key clock properties both in a human cell line and in a unicellular alga that diverged from each other more than 1 billion years ago. Given the essential role of Mg(2+) as a cofactor for ATP, a functional consequence of [Mg(2+)]i oscillations is dynamic regulation of cellular energy expenditure over the daily cycle. Mechanistically, we find that these rhythms provide bilateral feedback linking rhythmic metabolism to clock-controlled gene expression. The global regulation of nucleotide triphosphate turnover by intracellular Mg(2+) availability has potential to impact upon many of the cell's more than 600 MgATP-dependent enzymes and every cellular system where MgNTP hydrolysis becomes rate limiting. Indeed, we find that circadian control of translation by mTOR is regulated through [Mg(2+)]i oscillations. It will now be important to identify which additional biological processes are subject to this form of regulation in tissues of multicellular organisms such as plants and humans, in the context of health and disease. PMID:27074515

  15. Leptin resistance and the response to positive energy balance

    PubMed Central

    Morrison, Christopher D.

    2008-01-01

    Animals readily reduce food intake and normalize body weight following a period of involuntary overfeeding, suggesting that regulatory systems are engaged to defend against excess weight gain. However, these data exist in the background of an ongoing obesity epidemic, where the ready availability of palatable, energy dense foods often leads to obesity. Currently we know very little about the mechanisms underlying the normalization of body weight following involuntary overfeeding, nor do we fully understand why select individuals successfully remain lean despite living in an obesigenic environment. Recent progress in the study of leptin signaling indicates that manipulations which enhance leptin sensitivity reduce food intake and attenuate diet-induced obesity, while reductions in leptin signaling predispose to obesity. While it remains unclear whether a failure or insufficiency in the weight regulatory system contributes to obesity, this work highlights the importance of this system for the regulation of body weight and its potential value for the treatment of obesity. Nonetheless, it is necessary to more clearly identify those mechanisms that protect lean individuals from weight gain and mediate the normalization of body weight that follows involuntary overfeeding, because it is only with this knowledge that we can clearly determine whether obesity is dependent on, or independent of, a failure in the weight regulatory system. PMID:18508097

  16. Impact of Balancing Area Size, Obligation Sharing, and Energy Markets on Mitigating Ramping Requirements in Systems with Wind Energy

    SciTech Connect

    Kirby, B.; Milligan, M.

    2008-01-01

    Balancing area reserve sharing holds the promise of significantly reducing wind integration costs. In a companion paper we examine wind integration costs as a function of balancing area size to determine if the larger system size helps mitigate wind integration cost increases. In this paper we turn to an examination of the NYISO sub-hourly energy market to understand how it incentivizes generators to respond to ramping signals without having to explicitly pay for the service. Because markets appear to have the ability of bringing out supply response in sub-hourly energy markets, and because existing thermal resources appear to have significant untapped ramping capability, we believe that a combination of fast energy markets and combined balancing area operations can increase the grid's ability to absorb higher wind penetrations without experiencing significant operational problems or costs.

  17. Distributed energy balance modeling of South Cascade Glacier, Washington and assessment of model uncertainty

    USGS Publications Warehouse

    Anslow, Faron S.; Hostetler, S.; Bidlake, W.R.; Clark, P.U.

    2008-01-01

    We have developed a physically based, distributed surface energy balance model to simulate glacier mass balance under meteorological and climatological forcing. Here we apply the model to estimate summer ablation on South Cascade Glacier, Washington, for the 2004 and 2005 mass balance seasons. To arrive at optimal mass balance simulations, we investigate and quantify model uncertainty associated with selecting from a range of physical parameter values that are not commonly measured in glaciological mass balance field studies. We optimize the performance of the model by varying values for atmospheric transmissivity, the albedo of surrounding topography, precipitation-elevation lapse rate, surface roughness for turbulent exchange of momentum, and snow albedo aging coefficient. Of these the snow aging parameter and precipitation lapse rates have the greatest influence on the modeled ablation. We examined model sensitivity to varying parameters by performing an additional 103 realizations with parameters randomly chosen over a ??5% range centered about the optimum values. The best fit suite of model parameters yielded a net balance of -1.69??0.38 m water equivalent (WE) for the 2004 water year and -2.10??0.30 m WE up to 11 September 2005. The 2004 result is within 3% of the measured value. These simulations account for 91% and 93% of the variance in measured ablation for the respective years. Copyright 2008 by the American Geophysical Union.

  18. Low Calorie Sweetener (LCS) use and energy balance.

    PubMed

    Peters, John C; Beck, Jimikaye

    2016-10-01

    For thirty years there has been a debate about whether low calorie sweeteners (LCS) provide a benefit for body weight management. Early studies showed that when consumed alone in a beverage appetite and food intake were increased. Some, observational longitudinal cohort studies reported an association between LCS usage and increasing BMI, suggesting that LCS may actually promote weight gain. In the ensuing decades numerous additional observational and experimental trials have been conducted with the experimental trials nearly uniformly showing a benefit for LCS, either in weight loss or weight gain prevention. The observational trials have been more inconsistent with two recent meta-analyses indicating either a small positive association between LCS usage and BMI (weighted group mean correlation, p=0.03) or an inverse association with body weight change (-1.35 kg, p=.004). Numerous potential mechanisms have been explored, mostly in animal models, in an attempt to explain this association but none have yet been proven in humans. It is also possible that the association between LCS and BMI increase in the observational studies may be due to reverse causality or residual confounding. Randomized controlled trials are consistent in showing a benefit of LCS which suggests that simple behavioral engagement by individuals attempting to control their weight is a sufficiently strong signal to overcome any potential mechanism that might act to promote energy intake and weight gain. Based on existing evidence, LCS can be a useful tool for people actively engaged in managing their body weight for weight loss and maintenance. PMID:27061939

  19. Energy balance, body composition, sedentariness and appetite regulation: pathways to obesity.

    PubMed

    Hopkins, Mark; Blundell, John E

    2016-09-01

    Energy balance is not a simple algebraic sum of energy expenditure and energy intake as often depicted in communications. Energy balance is a dynamic process and there exist reciprocal effects between food intake and energy expenditure. An important distinction is that of metabolic and behavioural components of energy expenditure. These components not only contribute to the energy budget directly, but also by influencing the energy intake side of the equation. It has recently been demonstrated that resting metabolic rate (RMR) is a potential driver of energy intake, and evidence is accumulating on the influence of physical activity (behavioural energy expenditure) on mechanisms of satiety and appetite control. These effects are associated with changes in leptin and insulin sensitivity, and in the plasma levels of gastrointestinal (GI) peptides such as glucagon-like peptide-1 (GLP-1), ghrelin and cholecystokinin (CCK). The influence of fat-free mass on energy expenditure and as a driver of energy intake directs attention to molecules emanating from skeletal tissue as potential appetite signals. Sedentariness (physical inactivity) is positively associated with adiposity and is proposed to be a source of overconsumption and appetite dysregulation. The molecular signals underlying these effects are not known but represent a target for research. PMID:27503946

  20. Active Learning and Just-in-Time Teaching in a Material and Energy Balances Course

    ERIC Educational Resources Information Center

    Liberatore, Matthew W.

    2013-01-01

    The delivery of a material and energy balances course is enhanced through a series of in-class and out-of-class exercises. An active learning classroom is achieved, even at class sizes over 150 students, using multiple instructors in a single classroom, problem solving in teams, problems based on YouTube videos, and just-in-time teaching. To avoid…

  1. Enhancing Energy Balance Education through Physical Education and Self-Monitoring Technology

    ERIC Educational Resources Information Center

    Chen, Senlin; Zhu, Xihe; Kim, Youngwon; Welk, Gregory; Lanningham-Foster, Lorraine

    2016-01-01

    Schools are positioned to play a key role in nurturing students with knowledge and behaviours associated with healthful living. Our study examined the effects of an intervention on energy balance (EB) knowledge. Twelve 6th and 7th grade classrooms (n = 140) were assigned to receive either two standardised lessons on EB or a combined intervention…

  2. Alternative Resources for Curriculum Balance in Nutrition, Economics, Energy, Environmental, Consumer & Citizenship Education.

    ERIC Educational Resources Information Center

    Harty, Sheila, Comp.

    This annotated directory lists selected informational and educational resources in the subject areas predominant in corporate education efforts. Organized by categories of nutrition, economics, energy, environmental consumer and citizenship education, this list is intended to help provide a balance of resources and perspectives for the classroom…

  3. Energy balance of irrigated and dryland cotton in the Southern High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton (Gossypium hirsutum) is a major crop in the Southern High Plains that is produced under both irrigated and dryland cultures. In 2008, the energy balance components (net radiation, soil heat flux, sensible heat flux, and latent heat flux) were measured at Bushland, Texas. Four precision weighi...

  4. Ninth Graders' Energy Balance Knowledge and Physical Activity Behavior: An Expectancy-Value Perspective

    ERIC Educational Resources Information Center

    Chen, Senlin; Chen, Ang

    2012-01-01

    Expectancy beliefs and task values are two essential motivators in physical education. This study was designed to identify the relation between the expectancy-value constructs (Eccles & Wigfield, 1995) and high school students' physical activity behavior as associated with their energy balance knowledge. High school students (N = 195) in two…

  5. Effect of fescue toxicosis on ruminal kinetics, nitrogen and energy balance in Holstein steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to examine alteration of ruminal kinetics, as well as N and energy balance during fescue toxicosis. Six ruminally cannulated Holstein steers (BW=217 ±7 kg) were weight-matched into pairs and pair-fed throughout a cross-over design experiment with a 2x2 factorial treatment str...

  6. Changes in Energy Balance Following Smoking Cessation and Resumption of Smoking in Women.

    ERIC Educational Resources Information Center

    Perkins, Kenneth A.; And Others

    1990-01-01

    Prospectively examined caloric intake, resting metabolic rate (RMR), leisure time physical activity, and sensitivity and preference for sweet taste in seven female smokers during normal smoking, complete cessation, and resumption of smoking. Findings suggest that smoking cessation may cause rapid change in energy balance which is quickly reversed…

  7. ENERGY BALANCE COMPARISON AMONG TILLAGE PRACTICES IN CORN AND CORN-SOYBEAN SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction There is little information available on the effect of common management practices on the energy balance of corn and soybean cropping systems. This type of information is needed to assess the sustainability of these systems. Such information will also be useful for designing improved cr...

  8. Lysimetric evaluation of simplified surface energy balance approach in the Texas High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data to estimate evapotranspiration (ET) regionally. However, most EB models are complex to use and efforts are being made to simplify procedures mainly through the scaling of reference ET. The Simplified Surfa...

  9. The Martian climate: Energy balance models with CO2/H2O atmospheres

    NASA Technical Reports Server (NTRS)

    Hoffert, M. I.

    1985-01-01

    Coupled equations are developed for mass and heat transport in a seasonal Mars model with condensation and sublimation of CO2 at the polar caps. Topics covered include physical considerations of planetary as mass and energy balance; effects of phase changes at the surface on mass and heat flux; atmospheric transport and governing equations; and numerical analysis.

  10. Application of radiometric surface temperature for surface energy balance estimation: John Monteith's contributions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 25 years ago, Huband and Monteith paper’s investigating the radiative surface temperature and the surface energy balance of a wheat canopy, highlighted the key issues in computing fluxes with radiometric surface temperature. These included the relationship between radiometric and aerodynamic s...

  11. Comparison of four different energy balance models for estimating evapotranspiration in the Midwestern United States

    USGS Publications Warehouse

    Singh, Ramesh K.; Senay, Gabriel B.

    2016-01-01

    The development of different energy balance models has allowed users to choose a model based on its suitability in a region. We compared four commonly used models—Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) model, Surface Energy Balance Algorithm for Land (SEBAL) model, Surface Energy Balance System (SEBS) model, and the Operational Simplified Surface Energy Balance (SSEBop) model—using Landsat images to estimate evapotranspiration (ET) in the Midwestern United States. Our models validation using three AmeriFlux cropland sites at Mead, Nebraska, showed that all four models captured the spatial and temporal variation of ET reasonably well with an R2 of more than 0.81. Both the METRIC and SSEBop models showed a low root mean square error (<0.93 mm·day−1) and a high Nash–Sutcliffe coefficient of efficiency (>0.80), whereas the SEBAL and SEBS models resulted in relatively higher bias for estimating daily ET. The empirical equation of daily average net radiation used in the SEBAL and SEBS models for upscaling instantaneous ET to daily ET resulted in underestimation of daily ET, particularly when the daily average net radiation was more than 100 W·m−2. Estimated daily ET for both cropland and grassland had some degree of linearity with METRIC, SEBAL, and SEBS, but linearity was stronger for evaporative fraction. Thus, these ET models have strengths and limitations for applications in water resource management.

  12. Potential Errors in the Application of Thermal-Based Energy Balance Models with Coarse Resolution Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A thermal infrared (TIR)-based two-source (soil + vegetation) energy balance (TSEB) model, validated with remotely sensed imagery over a wide variety of landscapes, is applied to to the Texas High Plains region characterized by significant variability in vegetation cover and soil moisture conditions...

  13. Breath carbon stable isotope ratios identify changes in energy balance and substrate utilization in humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid detection of shifts in substrate utilization and energy balance would provide a compelling biofeedback tool to enable individuals to lose weight. In a pilot study, we tested whether the natural abundance of exhaled carbon stable isotope ratios (breath d13C values) reflects shifts between negat...

  14. Analysis of the balancing of the wind and solar energy resources in Andalusia (Southern Spain)

    NASA Astrophysics Data System (ADS)

    Santos-Alamillos, F. J.; Pozo-Vazquez, D.; Lara-Fanego, V.; Ruiz-Arias, J. A.; Hernandez-Alvaro, J.; Tova-Pescador, J.

    2010-09-01

    A higher penetration of the renewable energy in the electric system in the future will be conditioned to a reduction of the uncertainty of the yield. A way to obtain this goal is to analyze the balancing between the productions of different sources of renewable energy, trying to combine these productions. In this work we analyze, from a meteorological point of view, the balancing between wind and solar energy resources in Andalusia (southern Iberian Peninsula). To this end, wind speed and global radiation data corresponding to an one year integration of the Weather Research and Forecasting (WRF) Numerical Weather Prediction (NWP) model were analyzed. Two method of analysis were used: a point correlation analysis and a Canonical Correlation Analysis (CCA). Results from these analyses allow obtaining, eventually, areas of local and distributed balancing between the wind and solar energy resources. The analysis was carried out separately for the different seasons of the year. Results showed, overall, a considerable balancing effect between the wind and solar resources in the mountain areas of the interior of the region, along the coast of the central part of the region and, specially, in the coastal area near the Gibraltar strait. Nevertheless, considerable differences were found between the seasons of the year, which may lead to compensating effects. Autumn proved to be the season with the most significant results.

  15. Estimates of the climatological land surface energy- and water balance derived from thermodynamic constraints

    NASA Astrophysics Data System (ADS)

    Kleidon, Axel; Renner, Maik; Porada, Philipp

    2015-04-01

    The land surface energy and water balances are tightly coupled by the partitioning of absorbed solar radiation into terrestrial radiation and the turbulent fluxes of sensible and latent heat, as well as the partitioning of precipitation into evaporation and runoff. Evaporation forms the critical link between these two balances. Its rate is strongly affected by turbulent exchange as it provides the means to efficiently exchange moisture between the heated, moist surface and the cooled, dry atmosphere. Here, we use the constraint that this mass exchange operates at the thermodynamic limit of maximum power to derive analytical expressions for the partitioning of the surface energy and water balances on land. We use satellite-derived forcing of absorbed solar radiation, surface temperature and precipitation to derive simple spatial estimates for the annual mean fluxes of sensible and latent heat and evaluate these estimates with the ERA-Interim reanalysis data set and observations of the discharge of large river basins. Given the extremely simple approach, we find that our estimates explain the climatic mean variations in net radiation, evaporation, and river discharge reasonably well. We conclude that our analytical, minimum approach provides adequate first order estimates of the surface energy and water balance on land and that the thermodynamic limit of maximum power provides a useful closure assumption to constrain the energy partitioning at the land surface.

  16. Potential errors in the application of thermal-based energy balance models with coarse resolution data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A thermal infrared (TIR)-based two-source (soil + vegetation) energy balance (TSEB) model validated with remotely sensed imagery over a wide variety of landscapes is applied to an agricultural region with significant variability in vegetation cover and soil moisture conditions. The TSEB model uses ...

  17. Improved Student Achievement Using Personalized Online Homework for a Course in Material and Energy Balances

    ERIC Educational Resources Information Center

    Liberatore, Matthew W.

    2011-01-01

    Personalized, online homework was used to supplement textbook homework, quizzes, and exams for one section of a course in material and energy balances. The objective of this study was to test the hypothesis that students using personalized, online homework earned better grades in the course. The online homework system asks the same questions of…

  18. Albedo, internal heat, and energy balance of Jupiter, preliminary results of the Voyager infrared investigation

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.; Conrath, B. J.; Herath, L. W.; Kunde, V. G.; Pirraglia, J. A.

    1980-01-01

    The in flight calibration of the radiometer and the Michelson interferometer of the Voyager 1 infrared instrument is discussed. The calibrated full disk measurements are applied to derive values of the albedo, the thermal emission and the global energy balance of Jupiter.

  19. Improving surface energy balance closure by reducing errors in soil heat flux measurement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The flux plate method is the most commonly employed method for measuring soil heat flux (G) in surface energy balance studies. Although relatively simple to use, the flux plate method is susceptible to significant errors. Two of the most common errors are heat flow divergence around the plate and fa...

  20. Tillage and rotation effect on corn - soybean energy balances in eastern Nebraska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Data from a field experiment conducted in eastern Nebraska over 16 yr (1986-2001) were used to determine the energy balance of corn (Zea mays L.) and soybean (Glycine max L.) as affected by tillage treatments and rotation. Tillage treatments included chisel plow, tandom disk, moldboard plow, ridge-t...

  1. Two-source energy balance model estimates of evapotranspiration using component and composite surface temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The two-source energy balance model (TSEB) can estimate evaporation (E), transpiration (T), and evapotranspiration (ET) of vegetated surfaces, which has important applications in water resources management for irrigated crops. The TSEB requires soil (TS) and canopy (TC) surface temperatures to solv...

  2. Food Intake Recording Software System, version 4 (FIRSSt4): A self-completed 24-h dietary recall for children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Food Intake Recording Software System, version 4 (FIRSSt4), is a web-based 24-h dietary recall (24 hdr) self-administered by children based on the Automated Self-Administered 24-h recall (ASA24) (a self-administered 24 hdr for adults). The food choices in FIRSSt4 are abbreviated to include only ...

  3. Coming Full Circle: Contributions of Central and Peripheral Oxytocin Actions to Energy Balance

    PubMed Central

    Blevins, James E.

    2013-01-01

    The neuropeptide oxytocin has emerged as an important anorexigen in the regulation of energy balance. Its effects on food intake have largely been attributed to limiting meal size through interactions in key regulatory brain regions such as the hypothalamus and hindbrain. Pharmacologic and pair-feeding studies indicate that its ability to reduce body mass extends beyond that of food intake, affecting multiple factors that determine energy balance such as energy expenditure, lipolysis, and glucose regulation. Systemic administration of oxytocin recapitulates many of its effects when administered centrally, raising the questions of whether and to what extent circulating oxytocin contributes to energy regulation. Its therapeutic potential to treat metabolic conditions remains to be determined, but data from diet-induced and genetically obese rodent models as well as application of oxytocin in humans in other areas of research have revealed promising results thus far. PMID:23270805

  4. Reciprocal Compensation to Changes in Dietary Intake and Energy Expenditure within the Concept of Energy Balance123

    PubMed Central

    Drenowatz, Clemens

    2015-01-01

    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

  5. Understanding metabolic alterations in space flight using quantitative models - Fluid and energy balance

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1985-01-01

    The results of an integrated multidisciplinary and multiexperimental investigation, using data from the Skylab program, of metabolic adaptation to space flight are summarized and discussed. The effects of space flight on fluid-electrolyte regulation, mechanisms of hormone disturbances, energy balance, and the etiology of weight loss are emphasized. A composite picture of the fluid, electrolyte, and energy response to weightlessness, based primarily on data gathered from the nine Skylab crewmen, is presented.

  6. Understanding metabolic alterations in space flight using quantitative models: fluid and energy balance

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1986-01-01

    This report summarizes many of the results obtained during the Skylab program, on metabolic changes during weightlessness. The examination of the data was conducted following an integrated multi-disciplinary and multi-experimental approach. Emphasis is given on several major aspects of metabolic adaptation to space flight: fluid-electrolyte regulation, mechanisms of hormone disturbances, energy balance and etiology of weight loss. The aim is to obtain a composite picture of the fluid, electrolyte and energy response to weightlessness.

  7. Distributed simulation of snowcover mass- and energy-balance in the boreal forest

    NASA Astrophysics Data System (ADS)

    Link, Timothy; Marks, Danny

    1999-10-01

    The accurate distributed simulation of snowpack deposition and ablation beneath forest canopies is complicated by the fact that vegetation canopies strongly affect the snow surface energy balance. The canopy alters the radiation balance of the snowcover and reduces the wind speed at the snow surface. Simple canopy adjustment algorithms for solar and thermal radiation and wind speed are used in conjunction with commonly available land cover classifications to spatially distribute sub-canopy solar and thermal radiation, air and soil temperature, humidity, wind speed, and precipitation. The distributed climate surfaces are used to drive a two-layer coupled energy- and mass-balance snowmelt model over two areas within the BOREAS study region for the 1994-1995 snow season. Model results are validated using both automatic and manually collected snow depth data. The simulated timing and rate of snowpack development and ablation at both study areas are well represented beneath the canopy types where validation data are present. Rigorous evaluation of model performance beneath the full range of canopy types requires information regarding the spatial distribution of snow covered area during the ablation period. This study demonstrates that given basic landcover parameters, relatively simple canopy adjustments coupled with an energy balance model can be used to estimate climate conditions and snowcover processes across a range of boreal forest covers.

  8. Snowpack energy balance analysis using field measurements in an Andean watershed

    NASA Astrophysics Data System (ADS)

    Stehr, Alejandra

    2014-05-01

    Depending on the relative altitude and ambient temperature, Andean watersheds present important snow coverage during winter season. Snowpack stores significant amount of water which is released to surface runoff and groundwater when solar radiation increases, mainly during the spring and summer season, controlling the shape of the annual hydrograph and affecting the water balance at monthly and shorter scales. Field measurements of snow cover in those areas are difficult to perform due to adverse climatic and topographic conditions. Therefore, it is useful to support the hydrological characterization of watersheds located in the high mountains with models representing runoff from melting, for example, models based on the energy balance of the snowpack. The objective of this work is to characterize and quantify the energy flows that control the accumulation and melting of snow cover, using field measurements. The work was done on the upper Malleco watershed, which is located in the Andes Mountain Range (38°20' - 38°41' S and 71°13' - 71°35' W) and has an area of 27 km2, elevations vary between 900 to 1789 m a.m.s.l. For the calculation of the different the energy balance components, two weather stations were installed in the study area, which recorded data every 15 minutes. The variables measured were: global solar radiation, net radiation, shortwave and longwave radiation, air temperature, relative humidity, wind speed and direction, soil heat flux, precipitation and snow depth. Two analyzes were performed: 1) Energy Balance 2010. Two representative periods of accumulation (1st July to 31st July) and melting (10 September to 10 October) were selected in one of the stations. 2) Energy Balance 2011. Energy balance for a 15 days period of accumulation (July 19 to August 3, 2011) was with the aim of comparing both meteorological stations. In all cases hourly energy fluxes, snow water equivalent and daily snow depth were calculated. The latter was compared with the

  9. Modeling the snow surface temperature with a one-layer energy balance snowmelt model

    NASA Astrophysics Data System (ADS)

    You, J.; Tarboton, D. G.; Luce, C. H.

    2014-12-01

    Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort to keep snowmelt modeling simple and parsimonious, the Utah Energy Balance (UEB) snowmelt model used only one layer but allowed the snow surface temperature to be different from the snow average temperature by using an equilibrium gradient parameterization based on the surface energy balance. Although this procedure was considered an improvement over the ordinary single layer snowmelt models, it still resulted in discrepancies between modeled and measured snowpack energy contents. In this paper we evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach when they are integrated as part of a complete energy and mass balance snowmelt model. The force-restore and modified force-restore approaches have not been incorporated into the UEB in early versions, even though Luce and Tartoton have done work in calculating the energy components using these approaches. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We introduce a method to adjust effective conductivity to account for the presence of ground near to a shallow snow surface. These parameterizations were tested against data from the Central Sierra Snow Laboratory, CA, Utah State University experimental farm, UT, and subnivean snow laboratory at Niwot Ridge, CO

  10. Effect of balanced protein energy supplementation during pregnancy on birth outcomes

    PubMed Central

    2011-01-01

    Background The nutritional status of the mother prior to and during pregnancy plays a vital role in fetal growth and development, and maternal undernourishment may lead to adverse perinatal outcomes including intrauterine growth restriction (IUGR). Several macronutrient interventions had been proposed for adequate protein and energy supplementation during pregnancy. The objective of this paper was to review the effect of balanced protein energy supplementation during pregnancy on birth outcomes. This paper is a part of a series of reviews undertaken for getting estimates of effectiveness of an intervention for input to Lives Saved Tool (LiST) model. Methods A literature search was conducted on PubMed, Cochrane Library and WHO regional data bases to identify randomized trials (RCTs) and quasi RCTs that evaluated the impact of balanced protein energy supplementation in pregnancy. Balanced protein energy supplementation was defined as nutritional supplementation during pregnancy in which proteins provided less than 25% of the total energy content. Those studies were excluded in which the main intervention was dietary advice to pregnant women for increase in protein energy intake, high protein supplementation (i.e. supplementation in which protein provides at least 25% of total energy content), isocaloric protein supplementation (where protein replaces an equal quantity of non-protein energy content), or low energy diet to pregnant women who are either overweight or who exhibit high weight gain earlier in gestation. The primary outcomes were incidence of small for gestational age (SGA) birth, mean birth weight and neonatal mortality. Quality of evidence was evaluated according to the Child Health Epidemiology Reference group (CHERG) adaptation of Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Results The final number of studies included in our review was eleven comprising of both RCTs and quasi-RCTs. Our meta-analysis indicates that

  11. Oxidative fuel selection and shivering thermogenesis during a 12- and 24-h cold-survival simulation.

    PubMed

    Haman, François; Mantha, Olivier L; Cheung, Stephen S; DuCharme, Michel B; Taber, Michael; Blondin, Denis P; McGarr, Gregory W; Hartley, Geoffrey L; Hynes, Zach; Basset, Fabien A

    2016-03-15

    Because the majority of cold exposure studies are constrained to short-term durations of several hours, the long-term metabolic demands of cold exposure, such as during survival situations, remain largely unknown. The present study provides the first estimates of thermogenic rate, oxidative fuel selection, and muscle recruitment during a 24-h cold-survival simulation. Using combined indirect calorimetry and electrophysiological and isotopic methods, changes in muscle glycogen, total carbohydrate, lipid, protein oxidation, muscle recruitment, and whole body thermogenic rate were determined in underfed and noncold-acclimatized men during a simulated accidental exposure to 7.5 °C for 12 to 24 h. In noncold-acclimatized healthy men, cold exposure induced a decrease of ∼0.8 °C in core temperature and a decrease of ∼6.1 °C in mean skin temperature (range, 5.4-6.9 °C). Results showed that total heat production increased by approximately 1.3- to 1.5-fold in the cold and remained constant throughout cold exposure. Interestingly, this constant rise in Ḣprod and shivering intensity was accompanied by a large modification in fuel selection that occurred between 6 and 12 h; total carbohydrate oxidation decreased by 2.4-fold, and lipid oxidation doubled progressively from baseline to 24 h. Clearly, such changes in fuel selection dramatically reduces the utilization of limited muscle glycogen reserves, thus extending the predicted time to muscle glycogen depletion to as much as 15 days rather than the previous estimates of approximately 30-40 h. Further research is needed to determine whether this would also be the case under different nutritional and/or colder conditions. PMID:26718783

  12. A new portable device for recording 24-h indirect blood pressure in hypertensive outpatients.

    PubMed

    Tochikubo, O; Kaneko, Y; Yokoi, H; Yukinari, Y

    1985-12-01

    To simplify 24-h blood pressure (BP) recording in hypertensive outpatients, we devised a new portable, automatic BP recorder and studied its accuracy and usefulness. The fully automatic recorder, measuring 5 x 16 x 18 cm with a cuff of usual size, weighs approximately 1 kg and is driven by a rechargeable battery. The cuff is inflated by a compact CO2 cartridge and two microphones are used to detect differentially the Korotkoff sounds in the upper arm. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) are automatically measured, displayed with the time of measurement, and recorded on a memory card at intervals of 15 min for 24 h. This equipment has high noise immunity and works very quietly. It predicts approximate BP during the period of increasing cuff pressure, and measures BP more quickly than the conventional method (the time required for each measurement was reduced by about half). Afterwards, mean values with standard deviations, trendgrams and histograms of BP and HR over a certain period of time can be displayed and recorded with an accessory analyser. The accuracy of the BP values recorded by this device were compared with those measured by the auscultatory method. The average differences were -0.6 +/- 2.1 (s.d.) mmHg for SBP and 0.2 +/- 3.0 mmHg for DBP (n = 152). The BP values by this method were also compared with those obtained directly from the brachial artery, the differences being -5.8 +/- 5.9/0.3 +/- 6.0 mmHg (n = 85). In 30 ambulatory hypertensive patients, 24-h BP was recorded using this recorder.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2856737

  13. 24h Urinary Sodium Excretion and Subsequent Change in Weight, Waist Circumference and Body Composition

    PubMed Central

    Larsen, Sofus C.; Ängquist, Lars; Sørensen, Thorkild I. A.; Heitmann, Berit L.

    2013-01-01

    Background In the same period as the increasing obesity epidemic, there has been an increased consumption of highly processed foods with a high salt content, and a few studies have suggested that a diet with a high salt content may be associated with obesity. Objective To investigate the association between 24 h urinary sodium excretion and subsequent change in body weight (BW), waist circumference (WC), body fat (BF) and fat free mass (FFM) among adults. Design A longitudinal population study based on the Danish part of the MONICA project, with examinations in 1987–1988 and 1993–1994. Complete information on 24 h urinary sodium excretion along with repeated measures of obesity, as well as on potential confounders, was obtained from 215 subjects. Linear regression was used to examine the association between sodium excretion, as a measure of salt consumption, and subsequent changes in BW, WC, BF and FFM, and further evaluated by restricted cubic splines. Stepwise adjustments were made for selected covariates. Results Neither the crude nor the adjusted models showed any statistically significant associations between sodium excretion and change in BW or WC. Likewise, we found no significant association between sodium excretion and change in BF and FFM in the unadjusted models. However, after adjusting for potential baseline confounders and the concurrent BW change, we found a significant increase in BF of 0.24 kg (P = 0.015, CI: 0.05 to 0.43) per 100 mmol increase in 24 h urinary sodium excretion (equivalent to 6 g of salt), during the 6-year study period. Moreover, during the same period, we found a significant association with FFM of −0.21 kg (P = 0.041, CI: −0.40 to −0.01). Conclusions These results suggest that a diet with a high salt content may have a negative influence on development in body composition by expanding BF and reducing FFM. PMID:23936079

  14. Identifying waking time in 24-h accelerometry data in adults using an automated algorithm.

    PubMed

    van der Berg, Julianne D; Willems, Paul J B; van der Velde, Jeroen H P M; Savelberg, Hans H C M; Schaper, Nicolaas C; Schram, Miranda T; Sep, Simone J S; Dagnelie, Pieter C; Bosma, Hans; Stehouwer, Coen D A; Koster, Annemarie

    2016-10-01

    As accelerometers are commonly used for 24-h measurements of daily activity, methods for separating waking from sleeping time are necessary for correct estimations of total daily activity levels accumulated during the waking period. Therefore, an algorithm to determine wake and bed times in 24-h accelerometry data was developed and the agreement of this algorithm with self-report was examined. One hundred seventy-seven participants (aged 40-75 years) of The Maastricht Study who completed a diary and who wore the activPAL3™ 24 h/day, on average 6 consecutive days were included. Intraclass correlation coefficient (ICC) was calculated and the Bland-Altman method was used to examine associations between the self-reported and algorithm-calculated waking hours. Mean self-reported waking hours was 15.8 h/day, which was significantly correlated with the algorithm-calculated waking hours (15.8 h/day, ICC = 0.79, P = < 0.001). The Bland-Altman plot indicated good agreement in waking hours as the mean difference was 0.02 h (95% limits of agreement (LoA) = -1.1 to 1.2 h). The median of the absolute difference was 15.6 min (Q1-Q3 = 7.6-33.2 min), and 71% of absolute differences was less than 30 min. The newly developed automated algorithm to determine wake and bed times was highly associated with self-reported times, and can therefore be used to identify waking time in 24-h accelerometry data in large-scale epidemiological studies. PMID:26837855

  15. Energy-balance and melt contributions of supraglacial lakes, Langtang Khola, Nepal

    NASA Astrophysics Data System (ADS)

    Miles, E. S.; Willis, I. C.; Pellicciotti, F.; Steiner, J. F.; Buri, P.; Arnold, N. S.

    2014-12-01

    As Himalayan debris-covered glaciers retreat and thin in response to climate warming, their long, low-gradient tongues generate substantial meltwater which often collects to form surface lakes. Supraglacial lakes on debris covered glaciers present a mechanism of atmosphere-glacier energy transfer that is poorly-studied, and only conceptually included in mass-balance studies. The ponded water can enhance energy transfer as compared to dry debris cover, while also acting as a reservoir of melt-available energy. Supraglacial lakes occur in association with debris-free ice cliffs, another poorly-constrained but critical component of glacier melt. Understanding the role of supraglacial lakes requires precise monitoring of lake volume, estimation of inlet and outlet flows, and consideration of the energy balance across three surfaces: atmosphere-lake, lake-ice, and lake-saturated debris layer. This research progresses previous modeling work on the energy and mass balance of such supraglacial lakes. Lakes were monitored during the monsoon of 2013 on Lirung Glacier in the Langtang Himal of Nepal with pressure transducers and temperature sensors, while UAV-derived DEMs were used to determine lake geometry. Lake albedo was measured to vary between 0.08 and 0.12, and a nearby on-glacier AWS was used to drive the energy balance. Results indicate that the lakes act as a significant recipient of energy, and suggest that lakes are an important part of an active supraglacial hydrologic system during the monsoon. Melt generated by the lake in contact with bare ice is calculated to be 3-5 cm/day, while energy conducted through saturated lake-bottom debris only resulted in 1-2 mm/day melt. The subaqueous melt rates are of similar magnitude to observed ice-cliff melt rates, allowing lake-cliff systems to persist. Energy leaving the lake system through englacial conduits may be the most important contribution to the glacier's mass balance, driving surface evolution to form new ice

  16. Advances in the two-source energy balance model:Partioning of evaporation and transpiration for row crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant...

  17. Advances in the two-source energy balance model:Partioning of evaporation and transpiration for row crops for cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant...

  18. On Increasing Network Lifetime in Body Area Networks Using Global Routing with Energy Consumption Balancing

    PubMed Central

    Tsouri, Gill R.; Prieto, Alvaro; Argade, Nikhil

    2012-01-01

    Global routing protocols in wireless body area networks are considered. Global routing is augmented with a novel link cost function designed to balance energy consumption across the network. The result is a substantial increase in network lifetime at the expense of a marginal increase in energy per bit. Network maintenance requirements are reduced as well, since balancing energy consumption means all batteries need to be serviced at the same time and less frequently. The proposed routing protocol is evaluated using a hardware experimental setup comprising multiple nodes and an access point. The setup is used to assess network architectures, including an on-body access point and an off-body access point with varying number of antennas. Real-time experiments are conducted in indoor environments to assess performance gains. In addition, the setup is used to record channel attenuation data which are then processed in extensive computer simulations providing insight on the effect of protocol parameters on performance. Results demonstrate efficient balancing of energy consumption across all nodes, an average increase of up to 40% in network lifetime corresponding to a modest average increase of 0.4 dB in energy per bit, and a cutoff effect on required transmission power to achieve reliable connectivity. PMID:23201987

  19. The energy balance and pressure in the solar transition zone for network and active region features

    NASA Technical Reports Server (NTRS)

    Nicolas, K. R.; Bartoe, J.-D. F.; Brueckner, G. E.; Vanhoosier, M. E.

    1979-01-01

    The electron pressure and energy balance in the solar transition zone are determined for about 125 network and active region features on the basis of high spectral and spatial resolution extreme ultraviolet spectra. Si III line intensity ratios obtained from the Naval Research Laboratory high-resolution telescope and spectrograph during a rocket flight are used as diagnostics of electron density and pressure for solar features near 3.5 x 10 to the 4th K. Observed ratios are compared with the calculated dependence of the 1301 A/1312 A and 1301 A/1296 A line intensity ratios on electron density, temperature and pressure. Electron densities ranging from 2 x 10 to the 10th/cu cm to 10 to the 12th/cu cm and active region pressures from 3 x 10 to the 15th to 10 to the 16th/cu cm K are obtained. Energy balance calculations reveal the balance of the divergence of the conductive flux and turbulent energy dissipation by radiative energy losses in a plane-parallel homogeneous transition zone (fill factor of 1), and an energy source requirement for a cylindrical zone geometry (fill factor less than 0.04).

  20. Properties of the total kinetic energy balance in wall-bounded turbulent flows

    NASA Astrophysics Data System (ADS)

    Zhou, Ang; Klewicki, Joseph

    2015-11-01

    The properties of the total kinetic energy balance in turbulent boundary layer and channel flows are explored empirically. The total kinetic energy transport equation, which is the combination of mean and turbulent kinetic energy transport equations, is appropriately simplified for fully developed turbulent channel flow and the two-dimensional flat plate boundary layer. Different from the turbulence kinetic energy equation, a suitable grouping of terms is found that cleanly segregates the leading balances in the total energy equation. Available high-quality data reveal a four-layer structure for the energetics that is qualitatively different from the four-layer description of the mean dynamics [Wei et al. 2005, J. Fluid Mech. 522, 303]. The wall-normal widths of the layers exhibit significant Reynolds number dependencies, and these are empirically quantified. Present findings indicate that each of the four layers is characterized by a predominance of some of the terms in the governing equations. Particular significance is attached to the ratio of the sum of viscous diffusion and dissipation terms to the production/turbulent diffusion term, since these groupings allow the characterization of the layer widths. The third layer exhibits a complex leading order balance exchange that is described in detail.

  1. Balancing the energy budget in free-ranging male Myotis daubentonii bats.

    PubMed

    Becker, Nina I; Tschapka, Marco; Kalko, Elisabeth K V; Encarnação, Jorge A

    2013-01-01

    Mammals use five main, mutually nonexclusive mechanisms to balance energy budgets: torpor, metabolic compensation, change in activity patterns, change in ingested energy, and/or variability in digestive efficiency. Bats, as small and actively flying mammals, have a high mass-specific energy demand; therefore, balancing mechanisms should be pronounced in this group. We found that male Myotis daubentonii exhibited marked variation in the relative importance of these different mechanisms during their period of seasonal activity in response to extrinsic (ambient temperature, insect abundance) and intrinsic (reproduction, body condition) factors. Cold ambient temperatures in spring facilitated long and frequent daily torpor bouts, whereas in early summer, increased energy intake was the dominant factor in energy balancing. Intake was further increased in late summer, when insect abundance was highest, and daily torpor bouts were shorter and less frequent than in early summer. In autumn, males used metabolic compensation to reduce their resting metabolic rate in addition to daily torpor. Metabolic compensation might be one of the mechanisms that allow males to maintain high body temperature during the day while decreasing the need for foraging time at night, thus maximizing their opportunities to mate. PMID:23629886

  2. Local 24-h hyperglycemia does not affect endothelium-dependent or -independent vasoreactivity in humans.

    PubMed

    Houben, A J; Schaper, N C; de Haan, C H; Huvers, F C; Slaaf, D W; de Leeuw, P W; Nieuwenhuijzen Kruseman, C

    1996-06-01

    Hyperglycemia induces regional hemodynamic changes, as suggested by animal studies. These hemodynamic changes may play an initiating role in the pathogenesis of diabetic microangiopathy. The aim of the present study was to evaluate the effects of acute local hyperglycemia for 24 h on basal human forearm muscle and skin blood flow and endothelium-dependent and -independent vasoreactivity. Local hyperglycemia (approximately 15 mM) was induced by infusion of 5% glucose into the brachial artery of the nondominant arm. In control experiments, the same individual amount of glucose was infused intravenously in the dominant arm to correct for possible systemic effects of the infused glucose. Vasoreactivity of the forearm vasculature was evaluated by local infusion of acetylcholine (ACh), sodium nitroprusside (SNP), NG-monomethyl-L-arginine (L-NMMA), and norepinephrine (NE) into the brachial artery. Regional hemodynamic measurements were performed at baseline and after 6, 12, and 24 h of local hyperglycemia. Median (with interquartile range) basal forearm (muscle) blood flow (FBF) was not influenced by the 24-h local hyperglycemia [infused-to-contralateral arm FBF ratio for glucose 1.32 (1.16-1.64) vs. control 1.54 (1.34-1.69)]. Skin microcirculatory blood flow (laser Doppler flowmetry, LDF) was not influenced by the 24-h local hyperglycemia [LDF ratio for glucose 1.00 (0.62-1.56) vs control 0.80 (0.58-1.14)]. In addition, the vasoreactivity of both muscle and skin (not shown) vasculature to ACh [percent change in FBF ratio for glucose 167% (81-263) vs. control 148% (94-211)], SNP [for glucose 486% (178-586) vs. control 293% (196-454)], L-NMMA [for glucose -36% (-56 to -22) vs. control -41% (-51 to -24)], and NE [for glucose -48% (-72 to -41) vs. control -66% (-79 to -33)] was also not affected by the local hyperglycemia. Thus, in contrast to animal studies, our results suggest that a moderate-to-severe hyperglycemia does not affect the regulation of basal blood flow or

  3. ENSO influence on surface energy and mass balance at Shallap Glacier, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Maussion, F.; Gurgiser, W.; Großhauser, M.; Kaser, G.; Marzeion, B.

    2015-05-01

    The El Niño/Southern Oscillation (ENSO) is a major driver of climate variability in the tropical Andes, where recent Niño and Niña events left an observable footprint on glacier mass balance. The nature and strength of the relationship between ENSO and glacier mass balance, however, varies between regions and time periods, leaving several unanswered questions about its exact mechanisms. The starting point of this study is a four-year long time series of distributed surface energy and mass balance (SEB/SMB) calculated using a process-based model driven by observations at Shallap Glacier (Cordillera Blanca, Peru). These data are used to calibrate a regression-based downscaling model that links the local SEB/SMB fluxes to atmospheric reanalysis variables on a monthly basis, allowing an unprecedented quantification of the ENSO influence on the SEB/SMB at climatological time scales (1980-2013, ERA-Interim period). We find a stronger and steadier anti-correlation between pacific sea surface temperature (SST) and glacier mass balance than previously reported. This relationship is most pronounced during the wet season (December-May) and at low altitudes where Niño (Niña) events are accompanied with a snowfall deficit (excess) and a higher (lower) radiation energy input. We detect a weaker but significant ENSO anti-correlation with total precipitation (Niño dry signal) and positive correlation with the sensible heat flux, but find no ENSO influence on sublimation. Sensitivity analyses comparing several downscaling methods and reanalysis datasets resulted in stable mass balance correlations with pacific SST but also revealed large uncertainties in computing the mass balance trend of the last decades. The newly introduced open-source downscaling tool can be applied easily to other glaciers in the tropics, opening new research possibilities on even longer time scales.

  4. ENSO influence on surface energy and mass balance at Shallap Glacier, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Maussion, F.; Gurgiser, W.; Großhauser, M.; Kaser, G.; Marzeion, B.

    2015-08-01

    The El Niño/Southern Oscillation (ENSO) is a major driver of climate variability in the tropical Andes, where recent Niño and Niña events left an observable footprint on glacier mass balance. The nature and strength of the relationship between ENSO and glacier mass balance, however, varies between regions and time periods, leaving several unanswered questions about its exact mechanisms. The starting point of this study is a 4-year long time series of distributed surface energy and mass balance (SEB/SMB) calculated using a process-based model driven by observations at Shallap Glacier (Cordillera Blanca, Peru). These data are used to calibrate a regression-based downscaling model that links the local SEB/SMB fluxes to atmospheric reanalysis variables on a monthly basis, allowing an unprecedented quantification of the ENSO influence on the SEB/SMB at climatological time scales (1980-2013, ERA-Interim period). We find a stronger and steadier anti-correlation between Pacific sea-surface temperature (SST) and glacier mass balance than previously reported. This relationship is most pronounced during the wet season (December-May) and at low altitudes where Niño (Niña) events are accompanied with a snowfall deficit (excess) and a higher (lower) radiation energy input. We detect a weaker but significant ENSO anti-correlation with total precipitation (Niño dry signal) and positive correlation with the sensible heat flux, but find no ENSO influence on sublimation. Sensitivity analyses comparing several downscaling methods and reanalysis data sets resulted in stable mass balance correlations with Pacific SST but also revealed large uncertainties in computing the mass balance trend of the last decades. The newly introduced open-source downscaling tool can be applied easily to other glaciers in the tropics, opening new research possibilities on even longer time scales.

  5. Dry period plane of energy: Effects on feed intake, energy balance, milk production, and composition in transition dairy cows.

    PubMed

    Mann, S; Yepes, F A Leal; Overton, T R; Wakshlag, J J; Lock, A L; Ryan, C M; Nydam, D V

    2015-05-01

    The objective was to investigate the effect of different dry cow feeding strategies on the degree of ketonemia postpartum. Epidemiologic studies provide evidence of an association between elevated β-hydroxybutyrate (BHBA) concentrations in postpartum dairy cows and a decreased risk for reproductive success as well as increased risk for several diseases in early lactation, such as displacement of the abomasum and metritis. The plane of energy fed to cows in the prepartum period has been shown to influence ketogenesis and the degree of negative energy balance postpartum. Our hypothesis was that a high-fiber, controlled-energy diet (C) fed during the dry period would lead to a lower degree of hyperketonemia in the first weeks postpartum compared with either a high-energy diet (H), or a diet where an intermediate level of energy would only be fed in the close-up period (starting at 28d before expected parturition), following the same controlled-energy diet in the far-off period. Hyperketonemia in this study was defined as a blood BHBA concentration of ≥1.2mmol/L. Holstein cows (n=84) entering parity 2 or greater were enrolled using a randomized block design and housed in individual tiestalls. All treatment diets were fed for ad libitum intake and contained monensin. Cows received the same fresh cow ration after calving. Blood samples were obtained 3 times weekly before and after calving and analyzed for BHBA and nonesterified fatty acids (NEFA). Milk components, production, and dry matter intake were recorded and energy balance was calculated. Repeated measures ANOVA was conducted for the outcomes dry matter intake, energy balance, BHBA and NEFA concentrations, milk and energy-corrected milk yield, as well as milk composition. Predicted energy balance tended to be less negative postpartum in group C and cows in this group had fewer episodes of hyperketonemia compared with both the intermediate group and group H in the first 3 wk after calving. Postpartum BHBA and

  6. Amplitude distribution and energy balance of small disturbances in plate flow

    NASA Technical Reports Server (NTRS)

    Schlichting, H

    1950-01-01

    The distribution of the correlation coefficient and of the amplitude of the disturbance velocities is calculated as a function of the distance from the wall for two neutral disturbances, one at the lower and one at the upper branch of the neutral stability curve. The energy balance of the disturbance motion is also investigated and it is found that as required for neutral stability the energy of the disturbance motion that is dissipated by viscosity is equal to the energy transferred to the disturbance motion from the main flow during one cycle.

  7. Modelling surface energy fluxes over a Dehesa ecosystem using a two-source energy balance model.

    NASA Astrophysics Data System (ADS)

    Andreu, Ana; Kustas, William. P.; Anderson, Martha C.; Carrara, Arnaud; Patrocinio Gonzalez-Dugo, Maria

    2013-04-01

    The Dehesa is the most widespread agroforestry land-use system in Europe, covering more than 3 million hectares in the Iberian Peninsula and Greece (Grove and Rackham, 2001; Papanastasis, 2004). It is an agro-silvo-pastural ecosystem consisting of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs, and it is recognized as an example of sustainable land use and for his importance in the rural economy (Diaz et al., 1997; Plieninger and Wilbrand, 2001). The ecosystem is influenced by a Mediterranean climate, with recurrent and severe droughts. Over the last decades the Dehesa has faced multiple environmental threats, derived from intensive agricultural use and socio-economic changes, which have caused environmental degradation of the area, namely reduction in tree density and stocking rates, changes in soil properties and hydrological processes and an increase of soil erosion (Coelho et al. 2004; Schnabel and Ferreira, 2004; Montoya 1998; Pulido and Díaz, 2005). Understanding the hydrological, atmospheric and physiological processes that affect the functioning of the ecosystem will improve the management and conservation of the Dehesa. One of the key metrics in assessing ecosystem health, particularly in this water-limited environment, is the capability of monitoring evaporation (ET). To make large area assessments requires the use of remote sensing. Thermal-based energy balance techniques that distinguish soil/substrate and vegetation contributions to the radiative temperature and radiation/turbulent fluxes have proven to be reliable in such semi-arid sparse canopy-cover landscapes. In particular, the two-source energy balance (TSEB) model of Norman et al. (1995) and Kustas and Norman (1999) has shown to be robust for a wide range of partially-vegetated landscapes. The TSEB formulation is evaluated at a flux tower site located in center Spain (Majadas del Tietar, Caceres). Its application in this environment is

  8. Energy balance in the solar transition region. II - Effects of pressure and energy input on hydrostatic models

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    The radiation of energy by hydrogen lines and continua in hydrostatic energy-balance models of the transition region between the solar chromosphere and corona is studied using models which assume that mechanical or magnetic energy is dissipated in the hot corona and is then transported toward the chromosphere down the steep temperature gradient of the transition region. These models explain the average quiet sun and also the entire range of variability of the Ly-alpha lines. The relations between the downward energy flux, the pressure of the transition region, and the different hydrogen emission are described.

  9. Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in Chinese Adults.

    PubMed

    Peng, Yaguang; Li, Wei; Wang, Yang; Chen, Hui; Bo, Jian; Wang, Xingyu; Liu, Lisheng

    2016-01-01

    24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods-Kawasaki, INTERSALT, and Tanaka-have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China. PMID:26895296

  10. Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in Chinese Adults

    PubMed Central

    Peng, Yaguang; Li, Wei; Wang, Yang; Chen, Hui; Bo, Jian; Wang, Xingyu; Liu, Lisheng

    2016-01-01

    24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods—Kawasaki, INTERSALT, and Tanaka—have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China. PMID:26895296

  11. The effect of cloud type on Earth's energy balance - Global analysis

    NASA Technical Reports Server (NTRS)

    Hartmann, Dennis L.; Ockert-Bell, Maureen E.; Michelsen, Marc L.

    1992-01-01

    The role of fractional area coverage by cloud types in the energy balance of the earth is investigated through joint use of International Satellite Cloud Climatology Project (ISCCP) C1 cloud data and Earth Radiation Budget Experiment (ERBE) broadband energy flux data for the one-year period March 1985 through February 1986. Multiple linear regression is used to relate the radiation budget data to the cloud data. Comparing cloud forcing estimates obtained from the ISCCP-ERBE regression with those derived from the ERBE scene identification shows generally good agreement except over snow, in tropical convective regions, and in regions that are either nearly cloudless or always overcast. It is suggested that a substantial fraction of the disagreement in longwave cloud forcing in tropical convective regions is associated with the fact that the ERBE scene identification does not take into account variations in upper-tropospheric water vapor. On a global average basis, low clouds make the largest contribution to the net energy balance of the Earth, because they cover such a large area and because their albedo effect dominates their effect on emitted thermal radiation. High, optically thick clouds can also very effectively reduce the energy balance, however, because their very high albedos overcome their low emission temperatures.

  12. A Satellite Perspective on Continental-Scale Energy Balance and Heat Transport

    NASA Astrophysics Data System (ADS)

    L'Ecuyer, Tristan

    2015-04-01

    Recent efforts to balance the surface and atmospheric energy budgets on global and regional scales using satellite-derived observation or observation-integrating datasets will be highlighted. In the absence of closure constraints, unrealistically large imbalances are found between net radiation into the surface and corresponding turbulent heat fluxes, particularly over the global oceans. These imbalances can be traced, in part, to the fact that component fluxes tend to be estimated independently with no explicit reliance on closure constraints. A new approach for simultaneously introducing energy and water cycle balance constraints will be described that adjusts all component fluxes based on their relative uncertainties. The method yields estimates of all components of the energy and water cycles and provides explicit metrics for assessing the extent to which global and regional budgets can be balanced within assumed error bounds. This presentation will provide an overview of the resulting continental-scale energy budgets and their annual cycles. The behavior of fluxes in land and oceanic regions will be contrasted in the context of understanding the annual cycle of heat transport between the oceans and continents.

  13. Hunger can be taught: Hunger Recognition regulates eating and improves energy balance

    PubMed Central

    Ciampolini, Mario; Lovell-Smith, H David; Kenealy, Timothy; Bianchi, Riccardo

    2013-01-01

    A set of spontaneous hunger sensations, Initial Hunger (IH), has been associated with low blood glucose concentration (BG). These sensations may arise pre-meal or can be elicited by delaying a meal. With self-measurement of BG, subjects can be trained to formally identify and remember these sensations (Hunger Recognition). Subjects can then be trained to ensure that IH is present pre-meal for most meals and that their pre-meal BG is therefore low consistently (IH Meal Pattern). IH includes the epigastric Empty Hollow Sensation (the most frequent and recognizable) as well as less specific sensations such as fatigue or light-headedness which is termed inanition. This report reviews the method for identifying IH and the effect of the IH Meal Pattern on energy balance. In adults, the IH Meal Pattern has been shown to significantly decrease energy intake by one-third, decrease preprandial BG, reduce glycosylated hemoglobin, and reduce insulin resistance and weight in those who are insulin resistant or overweight. Young children as well as adults can be trained in Hunger Recognition, giving them an elegant method for achieving energy balance without the stress of restraint-type dieting. The implications of improving insulin sensitivity through improved energy balance are as wide as improving immune activity. PMID:23825928

  14. Preliminary Estimation of Deoxynivalenol Excretion through a 24 h Pilot Study

    PubMed Central

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Font, Guillermina

    2015-01-01

    A duplicate diet study was designed to explore the occurrence of 15 Fusarium mycotoxins in the 24 h-diet consumed by one volunteer as well as the levels of mycotoxins in his 24 h-collected urine. The employed methodology involved solvent extraction at high ionic strength followed by dispersive solid phase extraction and gas chromatography determination coupled to mass spectrometry in tandem. Satisfactory results in method performance were achieved. The method’s accuracy was in a range of 68%–108%, with intra-day relative standard deviation and inter-day relative standard deviation lower than 12% and 15%, respectively. The limits of quantitation ranged from 0.1 to 8 µg/Kg. The matrix effect was evaluated and matrix-matched calibrations were used for quantitation. Only deoxynivalenol (DON) was quantified in both food and urine samples. A total DON daily intake amounted to 49.2 ± 5.6 µg whereas DON daily excretion of 35.2 ± 4.3 µg was determined. DON daily intake represented 68.3% of the established DON provisional maximum tolerable daily intake (PMTDI). Valuable preliminary information was obtained as regards DON excretion and needs to be confirmed in large-scale monitoring studies. PMID:25723325

  15. BDNFval66met affects neural activation pattern during fear conditioning and 24 h delayed fear recall

    PubMed Central

    Golkar, Armita; Lindström, Kara M.; Haaker, Jan; Öhman, Arne; Schalling, Martin; Ingvar, Martin

    2015-01-01

    Brain-derived neurotrophic factor (BDNF), the most abundant neutrophin in the mammalian central nervous system, is critically involved in synaptic plasticity. In both rodents and humans, BDNF has been implicated in hippocampus- and amygdala-dependent learning and memory and has more recently been linked to fear extinction processes. Fifty-nine healthy participants, genotyped for the functional BDNFval66met polymorphism, underwent a fear conditioning and 24h-delayed extinction protocol while skin conductance and blood oxygenation level dependent (BOLD) responses (functional magnetic resonance imaging) were acquired. We present the first report of neural activation pattern during fear acquisition ‘and’ extinction for the BDNFval66met polymorphism using a differential conditioned stimulus (CS)+ > CS− comparison. During conditioning, we observed heightened allele dose-dependent responses in the amygdala and reduced responses in the subgenual anterior cingulate cortex in BDNFval66met met-carriers. During early extinction, 24h later, we again observed heightened responses in several regions ascribed to the fear network in met-carriers as opposed to val-carriers (insula, amygdala, hippocampus), which likely reflects fear memory recall. No differences were observed during late extinction, which likely reflects learned extinction. Our data thus support previous associations of the BDNFval66met polymorphism with neural activation in the fear and extinction network, but speak against a specific association with fear extinction processes. PMID:25103087

  16. Creatinine measurements in 24 h urine by liquid chromatography--tandem Mass Spectrometry.

    PubMed

    Park, Eun-Kee; Watanabe, Takaho; Gee, Shirley J; Schenker, Marc B; Hammock, Bruce D

    2008-01-23

    A simple, sensitive, and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining urinary creatinine was developed and used to evaluate 24 h urine samples collected during an exposure study. Urine (1 microL) was diluted with methanol and then directly applied to LC-MS/MS. Under electrospray ionization (ESI) conditions, the transition molecules of creatinine and creatinine- d3 were observed at m/ z 114 > 44 and m/ z 117 > 47, respectively. The retention time of creatinine was 0.59 min. The linear range was 1-2000 ng/mL, with a detection limit in urine of 1 ng/mL. LC-MS/MS and colorimetric end-point methods were significantly associated ( R2 = 0.8785, p < 0.0001). The LC-MS/MS method to determine creatinine in 24 h urine samples had shorter retention times, was more sensitive, reliable, reproducible, simple, selective, and used a smaller sample size than other LC-MS/MS or commercial methods. PMID:18092755

  17. The impact of a 24-h ultra-marathon on salivary antimicrobial protein responses.

    PubMed

    Gill, S K; Teixeira, A M; Rosado, F; Hankey, J; Wright, A; Marczak, S; Murray, A; Costa, R J S

    2014-10-01

    Depressed oral respiratory mucosal immunity and increased incidence of upper respiratory symptoms are commonly reported after bouts of prolonged exercise. The current study observed the impact of a 24-h continuous overnight ultra-marathon competition (distance range: 122-208 km; ambient temperature range: 0-20 °C) on salivary antimicrobial protein responses and incidence of upper respiratory symptoms. Body mass, unstimulated saliva and venous blood samples were taken from ultra-endurance runners (n=25) and controls (n=17), before and immediately after competition. Upper respiratory symptoms were assessed during and until 4-weeks after event completion. Samples were analyzed for salivary IgA, lysozyme, α-amylase and cortisol in addition to plasma osmolality. Decreased saliva flow rate (p<0.001), salivary IgA (p<0.001) and lysozyme (p=0.015) secretion rates, and increased salivary α-amylase secretion rate (p<0.001) and cortisol responses (p<0.001) were observed post-competition in runners, with no changes being observed in controls. No incidences of upper respiratory symptoms were reported by participants. A 24-h continuous overnight ultra-marathon resulted in the depression of some salivary antimicrobial protein responses, but no incidences of upper respiratory symptoms were evident during or following competition. Salivary antimicrobial protein synergism, effective management of non-infectious episodes, maintaining euhydration, and (or) favourable environmental influences could have accounted for the low prevalence of upper respiratory symptoms. PMID:24886918

  18. [Assessment of duodenogastric reflux 24h variability in subjects with functional dyspepsia].

    PubMed

    Romanowski, Marek; Chojnacki, Jan; Gil, Jerzy; Piotrowski, Wojciech

    2004-01-01

    Symptoms of functional dyspepsia demonstrate significant variability, among others dependently on the time of the day and on consumed meals. The aim of the study was to find out whether duodenogastric reflux is observed in subjects with nonulcer (NUD) and dysmotor dyspepsia (DD) and whether its intensification changes within 24 h. Investigations comprised 25 subjects with NUD and 25 with DD, aged 19-43 years after exclusion of other diseases and H. pylori infection. The gastric content of bilirubin was registered with Bilitec 2000 Synectics Medical. Duodenogastric reflux episodes were observed in both groups but their intensification and 24h dynamics were differentiated. In subjects with DD total reflux index was significantly higher than in those with NUD (mean=18.0+/-9.5% and mean=6.3+/-4.1%; p<0.05). These differences were particularly visible in after meal (mean=21.2+/-7.9% and mean=10.4+/-6.6%; p<0.01) and night time (mean=8.7+/-3.6% and mean=2.9+/-0.9%; p<0.01). The results of the study indicate that bilimetry may be useful in differentiation of the form of dyspepsia and in selection of rational therapy. PMID:15603369

  19. Preliminary estimation of deoxynivalenol excretion through a 24 h pilot study.

    PubMed

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Font, Guillermina

    2015-03-01

    A duplicate diet study was designed to explore the occurrence of 15 Fusarium mycotoxins in the 24 h-diet consumed by one volunteer as well as the levels of mycotoxins in his 24 h-collected urine. The employed methodology involved solvent extraction at high ionic strength followed by dispersive solid phase extraction and gas chromatography determination coupled to mass spectrometry in tandem. Satisfactory results in method performance were achieved. The method's accuracy was in a range of 68%-108%, with intra-day relative standard deviation and inter-day relative standard deviation lower than 12% and 15%, respectively. The limits of quantitation ranged from 0.1 to 8 µg/Kg. The matrix effect was evaluated and matrix-matched calibrations were used for quantitation. Only deoxynivalenol (DON) was quantified in both food and urine samples. A total DON daily intake amounted to 49.2 ± 5.6 µg whereas DON daily excretion of 35.2 ± 4.3 µg was determined. DON daily intake represented 68.3% of the established DON provisional maximum tolerable daily intake (PMTDI). Valuable preliminary information was obtained as regards DON excretion and needs to be confirmed in large-scale monitoring studies. PMID:25723325

  20. The acceptability of repeat Internet-based hybrid diet assessment of previous 24-h dietary intake: administration of the Oxford WebQ in UK Biobank.

    PubMed

    Galante, Julieta; Adamska, Ligia; Young, Alan; Young, Heather; Littlejohns, Thomas J; Gallacher, John; Allen, Naomi

    2016-02-28

    Although dietary intake over a single 24-h period may be atypical of an individual's habitual pattern, multiple 24-h dietary assessments can be representative of habitual intake and help in assessing seasonal variation. Web-based questionnaires are convenient for the participant and result in automatic data capture for study investigators. This study reports on the acceptability of repeated web-based administration of the Oxford WebQ--a 24-h recall of frequency from a set food list suitable for self-completion from which energy and nutrient values can be automatically generated. As part of the UK Biobank study, four invitations to complete the Oxford WebQ were sent by email over a 16-month period. Overall, 176 012 (53% of those invited) participants completed the online version of the Oxford WebQ at least once and 66% completed it more than once, although only 16% completed it on all four occasions. The response rate for any one round of invitations varied between 34 and 26%. On most occasions, the Oxford WebQ was completed on the same day that they received the invitation, although this was less likely if sent on a weekend. Participants who completed the Oxford WebQ tended to be white, female, slightly older, less deprived and more educated, which is typical of health-conscious volunteer-based studies. These findings provide preliminary evidence to suggest that repeated 24-h dietary assessment via the Internet is acceptable to the public and a feasible strategy for large population-based studies. PMID:26652593

  1. Roles of divergent and rotational winds in the kinetic energy balance during intense convective activity

    NASA Technical Reports Server (NTRS)

    Fuelberg, H. E.; Browning, P. A.

    1983-01-01

    Contributions of divergent and rotational wind components to the synoptic-scale kinetic energy balance are described using rawinsonde data at 3 and 6 h intervals from NASA's fourth Atmospheric Variability experiment. Two intense thunderstorm complexes occurred during the period. Energy budgets are described for the entire computational region and for limited volumes that enclosed storm-induced, upper level wind maxima located poleward of convection. Although small in magnitude, the divergent wind component played an important role in the cross-contour generation and horizontal flux divergence of kinetic energy. The importance of V(D) appears directly related to the presence and intensity of convection. Although K(D) usually comprised less than 10 percent of the total kinetic energy content, generation of kinetic energy by V(D) was a major factor in the creation of upper-level wind maxima to the north of the storm complexes. Omission of the divergent wind apparently would lead to serious misrepresentations of the energy balance. A random error analysis is presented to assess confidence limits in the various energy parameters.

  2. An Energy Balance Model to Predict Chemical Partitioning in a Photosynthetic Microbial Mat

    NASA Technical Reports Server (NTRS)

    Hoehler, Tori M.; Albert, Daniel B.; DesMarais, David J.

    2006-01-01

    Studies of biosignature formation in photosynthetic microbial mat communities offer potentially useful insights with regards to both solar and extrasolar astrobiology. Biosignature formation in such systems results from the chemical transformation of photosynthetically fixed carbon by accessory microorganisms. This fixed carbon represents a source not only of reducing power, but also energy, to these organisms, so that chemical and energy budgets should be coupled. We tested this hypothesis by applying an energy balance model to predict the fate of photosynthetic productivity under dark, anoxic conditions. Fermentation of photosynthetically fixed carbon is taken to be the only source of energy available to cyanobacteria in the absence of light and oxygen, and nitrogen fixation is the principal energy demand. The alternate fate for fixed carbon is to build cyanobacterial biomass with Redfield C:N ratio. The model predicts that, under completely nitrogen-limited conditions, growth is optimized when 78% of fixed carbon stores are directed into fermentative energy generation, with the remainder allocated to growth. These predictions were compared to measurements made on microbial mats that are known to be both nitrogen-limited and populated by actively nitrogen-fixing cyanobacteria. In these mats, under dark, anoxic conditions, 82% of fixed carbon stores were diverted into fermentation. The close agreement between these independent approaches suggests that energy balance models may provide a quantitative means of predicting chemical partitioning within such systems - an important step towards understanding how biological productivity is ultimately partitioned into biosignature compounds.

  3. FTO knockdown in rat ventromedial hypothalamus does not affect energy balance

    PubMed Central

    van Gestel, Margriet A.; Sanders, Loek E.; de Jong, Johannes W.; Luijendijk, Mieneke C. M.; Adan, Roger A. H.

    2014-01-01

    Abstract Single nucleotide polymorphisms (SNPs) clustered in the first intron of the fat mass and obesity‐associated (FTO) gene has been associated with obesity. FTO expression is ubiquitous, with particularly high levels in the hypothalamic area of the brain. To investigate the region‐specific role of FTO, AAV technology was applied to knockdown FTO in the ventromedial hypothalamus (VMH). No effect of FTO knockdown was observed on bodyweight or parameters of energy balance. Animals were exposed twice to an overnight fast, followed by a high‐fat high‐sucrose (HFHS) diet for 1 week. FTO knockdown did not result in a different response to the diets. A region‐specific role for FTO in the VMH in the regulation of energy balance could not be found. PMID:25501432

  4. Botswana water and surface energy balance research program. Part 2: Large scale moisture and passive microwaves

    NASA Technical Reports Server (NTRS)

    Vandegriend, A. A.; Owe, M.; Chang, A. T. C.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. The research program consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components are explained in general and activities performed within the passive microwave research component are summarized. The microwave theory is discussed taking into account: soil dielectric constant, emissivity, soil roughness effects, vegetation effects, optical depth, single scattering albedo, and wavelength effects. The study site is described. The soil moisture data and its processing are considered. The relation between observed large scale soil moisture and normalized brightness temperatures is discussed. Vegetation characteristics and inverse modeling of soil emissivity is considered.

  5. New insights on the role of the endocannabinoid system in the regulation of energy balance.

    PubMed

    Gatta-Cherifi, B; Cota, D

    2016-02-01

    Within the past 15 years, the endocannabinoid system (ECS) has emerged as a lipid signaling system critically involved in the regulation of energy balance, as it exerts a regulatory control on every aspect related to the search, the intake, the metabolism and the storage of calories. An overactive endocannabinoid cannabinoid type 1 (CB1) receptor signaling promotes the development of obesity, insulin resistance and dyslipidemia, representing a valuable pharmacotherapeutic target for obesity and metabolic disorders. However, because of the psychiatric side effects, the first generation of brain-penetrant CB1 receptor blockers developed as antiobesity treatment were removed from the European market in late 2008. Since then, recent studies have identified new mechanisms of action of the ECS in energy balance and metabolism, as well as novel ways of targeting the system that may be efficacious for the treatment of obesity and metabolic disorders. These aspects will be especially highlighted in this review. PMID:26374449

  6. Aerosol influence on energy balance of the middle atmosphere of Jupiter.

    PubMed

    Zhang, Xi; West, Robert A; Irwin, Patrick G J; Nixon, Conor A; Yung, Yuk L

    2015-01-01

    Aerosols are ubiquitous in planetary atmospheres in the Solar System. However, radiative forcing on Jupiter has traditionally been attributed to solar heating and infrared cooling of gaseous constituents only, while the significance of aerosol radiative effects has been a long-standing controversy. Here we show, based on observations from the NASA spacecraft Voyager and Cassini, that gases alone cannot maintain the global energy balance in the middle atmosphere of Jupiter. Instead, a thick aerosol layer consisting of fluffy, fractal aggregate particles produced by photochemistry and auroral chemistry dominates the stratospheric radiative heating at middle and high latitudes, exceeding the local gas heating rate by a factor of 5-10. On a global average, aerosol heating is comparable to the gas contribution and aerosol cooling is more important than previously thought. We argue that fractal aggregate particles may also have a significant role in controlling the atmospheric radiative energy balance on other planets, as on Jupiter. PMID:26694318

  7. Aerosol influence on energy balance of the middle atmosphere of Jupiter

    NASA Astrophysics Data System (ADS)

    Zhang, Xi; West, Robert A.; Irwin, Patrick G. J.; Nixon, Conor A.; Yung, Yuk L.

    2015-12-01

    Aerosols are ubiquitous in planetary atmospheres in the Solar System. However, radiative forcing on Jupiter has traditionally been attributed to solar heating and infrared cooling of gaseous constituents only, while the significance of aerosol radiative effects has been a long-standing controversy. Here we show, based on observations from the NASA spacecraft Voyager and Cassini, that gases alone cannot maintain the global energy balance in the middle atmosphere of Jupiter. Instead, a thick aerosol layer consisting of fluffy, fractal aggregate particles produced by photochemistry and auroral chemistry dominates the stratospheric radiative heating at middle and high latitudes, exceeding the local gas heating rate by a factor of 5-10. On a global average, aerosol heating is comparable to the gas contribution and aerosol cooling is more important than previously thought. We argue that fractal aggregate particles may also have a significant role in controlling the atmospheric radiative energy balance on other planets, as on Jupiter.

  8. The albedo, effective temperature, and energy balance of Neptune, as determined from Voyager data

    NASA Technical Reports Server (NTRS)

    Pearl, J. C.; Conrath, B. J.

    1991-01-01

    Data from the Voyager infrared spectrometer and radiometer (IRIS) investigation are used in determining the albedo, effective temperature, and energy balance of Neptune. From broadband radiometric observations made at phase angles of 14 deg and 134 deg, together with measurements at intermediate phase angles from the literature, an orbital mean value of 0.290 +/-0.067 is obtained for the bolometric Bond albedo. This yields an equilibrium temperature Teq = 46.6 +/-1.1 K. From thermal spectra obtained over latitudes from pole to pole an effective temperature Teff = 59.3 +/-0.8 K is derived. This represents a substantial improvement over previously determined values. The energy balance of Neptune is therefore E = 2.61 +/-0.28, which is in agreement with previous results. The reduced uncertainty in this value is due to the improved determination of the effective temperature.

  9. Net radiation, sensible and latent heat flux densities on slopes computed by the energy balance method

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo; Qian, Ping

    1990-01-01

    Energy balance components obtained over five grass-covered sloping surfaces near Manhattan, KS, using the Bowen ratio energy balance technique with the instruments mounted horizontally were compared with calculated values when the instruments were mounted parallel to the surfaces. Hourly values of the components changed when the instruments were parallel to the surfaces. The changes were larger at low solar angles (spring and fall) and on steeper slopes. An area average of daylight totals, assuming that all aspects were equally represented, changed only 0.1 percent on June 6 and 2.3 percent on October 11. The calculations, extended to steeper slopes, indicated small changes in the daylight totals for slopes of less than 10 deg.

  10. The albedo, effective temperature, and energy balance of Uranus, as determined from Voyager IRIS data

    NASA Technical Reports Server (NTRS)

    Pearl, J. C.; Conrath, B. J.; Hanel, R. A.; Pirraglia, J. A.; Coustenis, A.

    1990-01-01

    The albedo, T(eff), and energy balance of Uranus are presently derived from Voyager IR Spectrometer and Radiometer data. By obtaining the absolute phase curve of Uranus, it has become possible to evaluate the Bond albedo without making separate determinations of the geometric albedo and phase integral. An orbital mean value for the bolometric Bond albedo of 0.3 + or - 0.049 yields an equilibrium temperature of 58.2 + or - 1.0 K. Thermal spectra from pole-to-pole latitude coverage establish a T(eff) of 59.1 + or - 0.3 K, leading to an energy balance of 1.06 + or - 0.08 for Uranus.

  11. Aerosol influence on energy balance of the middle atmosphere of Jupiter

    PubMed Central

    Zhang, Xi; West, Robert A.; Irwin, Patrick G. J.; Nixon, Conor A.; Yung, Yuk L.

    2015-01-01

    Aerosols are ubiquitous in planetary atmospheres in the Solar System. However, radiative forcing on Jupiter has traditionally been attributed to solar heating and infrared cooling of gaseous constituents only, while the significance of aerosol radiative effects has been a long-standing controversy. Here we show, based on observations from the NASA spacecraft Voyager and Cassini, that gases alone cannot maintain the global energy balance in the middle atmosphere of Jupiter. Instead, a thick aerosol layer consisting of fluffy, fractal aggregate particles produced by photochemistry and auroral chemistry dominates the stratospheric radiative heating at middle and high latitudes, exceeding the local gas heating rate by a factor of 5–10. On a global average, aerosol heating is comparable to the gas contribution and aerosol cooling is more important than previously thought. We argue that fractal aggregate particles may also have a significant role in controlling the atmospheric radiative energy balance on other planets, as on Jupiter. PMID:26694318

  12. Energy and radiation balance components for three grass surfaces near Kursk, Russia

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.

    1992-01-01

    The energy and radiation balance components were determined over three grass surfaces, located on the Streletskaya steppe during July 1991. The Bowen ratio energy balance method was used to determine the sensible and latent heat flux densities using six computer controlled systems. A total of 126 variables were sampled, including global, diffuse, and reflected solar radiation, long wave radiation (up and down), net radiation, photosynthetically active radiation above and below the vegetation, infrared surface temperatues, soil temperature and heat flow, air temperature and vapor pressure at two levels, wind speed and direction, and precipitation. The ranking of the sites from greatest to smallest for net radiation and latent heat flux density were preserve, mowed in 1990, and mowed in 1991. The ranking of the sites from greatest to smallest for sensible heat flux density were mowed in 1990, mowed in 1991, and preserve.

  13. The albedo, effective temperature, and energy balance of Uranus, as determined from Voyager IRIS data

    SciTech Connect

    Pearl, J.C.; Conrath, B.J.; Hanel, R.A.; Pirraglia, J.A.; Coustenis, A. Paris, Observatoire, Meudon )

    1990-03-01

    The albedo, T(eff), and energy balance of Uranus are presently derived from Voyager IR Spectrometer and Radiometer data. By obtaining the absolute phase curve of Uranus, it has become possible to evaluate the Bond albedo without making separate determinations of the geometric albedo and phase integral. An orbital mean value for the bolometric Bond albedo of 0.3 + or - 0.049 yields an equilibrium temperature of 58.2 + or - 1.0 K. Thermal spectra from pole-to-pole latitude coverage establish a T(eff) of 59.1 + or - 0.3 K, leading to an energy balance of 1.06 + or - 0.08 for Uranus. 39 refs.

  14. Carbon and energy balances for cellulosic biofuel crops in U.S. Midwest

    NASA Astrophysics Data System (ADS)

    Gerlfand, I.; Hamilton, S. K.; Robertson, G. P.

    2012-04-01

    Cellulosic biofuels produced on lands not used for food production have the potential to avoid competition for food and associated indirect land use costs. Understanding the carbon and energy balance implications for different cellulosic production systems is important for the development of decision making tools and policies. Here we present carbon and energy balances of alternative agricultural management. We use 20 years of data from KBS LTER experiments to produce farm level CO2 and energy balances for different management practices. Our analyses include four grain and four perrenial systems in the U.S. Midwest: corn (Zea mays) - soybean (Glycine max) - wheat (Triticum aestivum) rotations managed with (1) conventional tillage, (2) no till, (3) low chemical input, and (4) biologically-based (organic) practices; (5) continuous alfalfa (Medicago sativa); (6) Poplar; and (7,8) Successionnal fields, both fertilized and unfertilized. Measurements include fluxes of N2O and CH4, soil organic carbon change, agricultural yields, and agricultural inputs (e.g. fertilization and farm fuel use). Our results indicate that management decisions such as tillage and plant types have a great influence on the net carbon and energy balances and benefits of cellulosic biofuels production. Specifically, we show that cellulosic biofuels produced from an early successional, minimally managed system have a net C sequestration (i.e., negative C balance) of -841±46 gCO2e m-2 yr-1 vs. -594±93 gCO2e m-2 yr-1 for more productive and management intensive alfalfa, and vs. 232±157 gCO2e m-2 for poplar. The reference agricultural system (a conventionally tilled corn-soybean-wheat rotation) has net sequestration of -149±33 g CO2e m-2 yr-1. Among the annual grain crops, average energy costs of farming for the different systems ranged from 4.8 GJ ha-1 for the organic system to 7.1 GJ ha-1 for the conventional; the no-till system was also low at 4.9 GJ ha-1 and the low-chemical input system

  15. Fluid and electrolyte balance during 24-hour fluid and/or energy restriction.

    PubMed

    James, Lewis J; Shirreffs, Susan M

    2013-12-01

    Weight categorized athletes use a variety of techniques to induce rapid weight loss (RWL) in the days leading up to weigh in. This study examined the fluid and electrolyte balance responses to 24-hr fluid restriction (FR), energy restriction (ER) and fluid and energy restriction (F+ER) compared with a control trial (C), which are commonly used techniques to induce RWL in weight category sports. Twelve subjects (six male, six female) received adequate energy and water (C) intake, adequate energy and restricted water (~10% of C; FR) intake, restricted energy (~25% of C) and adequate water (ER) intake or restricted energy (~25% of C) and restricted (~10% of C) water intake (F+ER) in a randomized counterbalanced order. Subjects visited the laboratory at 0 hr, 12 hr, and 24 hr for blood and urine sample collection. Total body mass loss was 0.33% (C), 1.88% (FR), 1.97% (ER), and 2.44% (F+ER). Plasma volume was reduced at 24 hr during FR, ER, and F+ER, while serum osmolality was increased at 24 hr for FR and F+ER and was greater at 24 hr for FR compared with all other trials. Negative balances of sodium, potassium, and chloride developed during ER and F+ER but not during C and FR. These results demonstrate that 24 hr fluid and/ or energy restriction significantly reduces body mass and plasma volume, but has a disparate effect on serum osmolality, resulting in hypertonic hypohydration during FR and isotonic hypohydration during ER. These findings might be explained by the difference in electrolyte balance between the trials. PMID:24413436

  16. Comparison of Four Different Energy Balance Models for Estimating Evapotranspiration in the Midwest United States

    NASA Astrophysics Data System (ADS)

    Singh, R. K.; Senay, G. B.; Verdin, J. P.

    2015-12-01

    Availability of no-cost satellite images helped in development and utilization of remotely sensed images for water use estimation. Remotely sensed images are increasingly used for estimating evapotranspiration (ET) at different temporal and spatial scales. However, selecting any particular model from a plethora of energy balance models for estimating ET is challenging as each different model has its strengths and limitations. We compared four commonly used ET models, namely, Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) model, Surface Energy Balance Algorithm for Land (SEBAL) model, Surface Energy Balance System (SEBS) model, and Operational Simplified Surface Energy Balance (SSEBop) model using Landsat images for estimating ET in the Midwest United States. We validated our model results using three AmeriFlux cropland sites at Mead, Nebraska. Our results showed that the METRIC and the SSEBop model worked very well at these sites with a root mean square error (RMSE) of less than 1 mm/day and an R2 of 0.96 (N=24). The mean bias error (MBE) was less than 10% for both the METRIC and the SSEBop models. In contrast, the SEBAL and the SEBS models have relatively higher RMSE (> 1.7 mm/day) and MBE (> 27%). However, all four models captured the spatial and temporal variation of ET reasonably well (R2 > 0.80). We found that the model simplification of the SSEBop for operational capability was not at the expense of model accuracy. Since the SSEBop model is relatively less data intensive and independent of user/automatic selection of anchor (hot/dry and cold/wet) pixels, it is more user friendly and operationally efficient. The SSEBop model can be reliably used for estimating water use using Landsat and MODIS images at daily, weekly, monthly, or annual time scale even in data scarce regions for sustainable use of limited water resources.

  17. Mapping surface energy balance components by combining Landsat Thematic Mapper and ground-based meteorological data

    NASA Technical Reports Server (NTRS)

    Moran, M. Susan; Jackson, Ray D.; Raymond, Lee H.; Gay, Lloyd W.; Slater, Philip N.

    1989-01-01

    Surface energy balance components were evaluated by combining satellite-based spectral data with on-site measurements of solar irradiance, air temperature, wind speed, and vapor pressure. Maps of latent heat flux density and net radiant flux density were produced using Landsat TM data for three dates. The TM-based estimates differed from Bowen-ratio and aircraft-based estimates by less than 12 percent over mature fields of cotton, wheat, and alfalfa.

  18. The energy balance relation for weak solutions of the density-dependent Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Leslie, T. M.; Shvydkoy, R.

    2016-09-01

    We consider the incompressible inhomogeneous Navier-Stokes equations with constant viscosity coefficient and density which is bounded and bounded away from zero. We show that the energy balance relation for this system holds for weak solutions if the velocity, density, and pressure belong to a range of Besov spaces of smoothness 1/3. A density-dependent version of the classical Kármán-Howarth-Monin relation is derived.

  19. Mass by Energy Loss Quantitation as a Practical Sub-Microgram Balance

    SciTech Connect

    Palmblad, M; Bench, G; Vogel, J S

    2004-09-28

    A simple device integrating a thin film support and a standard microcentrifuge tube can be used for making solutions of accurately known concentration of any organic compound in a single step, avoiding serial dilution and the use of microgram balances. Nanogram to microgram quantities of organic material deposited on the thin film are quantified by ion energy loss and transferred to the microcentrifuge tube with high recovery.

  20. Mass and Energy Balance Modeling of Glaciers in the Upper Susitna Basin, Alaska

    NASA Astrophysics Data System (ADS)

    Hoffman, A.; Hock, R.; Aubry-Wake, C.; Bliss, A.; Gusmeroli, A.; Liljedahl, A.; Gillispie, L.; Wolken, G. J.

    2014-12-01

    The State of Alaska is reviving analyses of the Susitna River's hydroelectric potential by supporting a multitude of field and modeling studies for the proposed Susitna-Watana Hydroelectric project. Critical to any effective hydroelectric development is a firm understanding of the basin-wide controls on river runoff and how seasonal reservoir recharge may change over the course of the structure's life-span. Effectively projecting future changes in watershed-scale stream flow for the Susitna river demands understanding and quantifying glacier melt in the Alaskan range. Our research is restricted to a sub-catchment of the upper Susitna basin that feeds the Susitna River covering 2,230 km2, of which 25% is glacierized. The goals of our study are to investigate the spatial and seasonal variations of the energy balance and its components across the glaciers and to model resulting streamflow from the catchment for the summer of 2013 using two models of different complexity. We apply DEBAM, a distributive energy balance model and DETIM, an enhanced temperature-index model, both coupled to a linear-reservoir runoff model, to simulate hourly surface energy fluxes, melt rates and glacier runoff using meteorological observations from an automated weather station located in the ablation zone of the West Fork glacier. Model results are compared to measurements of streamflow and mass balance at 20 ablation stakes across the glacierized area. The largest source of energy contributing to 85% of melt is net radiation followed by the sensible and latent heat fluxes. Both models capture well the seasonal and diurnal variations in streamflow and show good agreement with the mass balance point observations. The discrepancies between modeled and measured discharge can be attributed to the high uncertainty in precipitation and initial snow cover across the unglaciated part of the basin which accounts for over 75% of the modeled area.

  1. Psychophysiological response and energy balance during a 14-h ultraendurance mountain running event.

    PubMed

    Clemente-Suárez, Vicente Javier

    2015-03-01

    Many studies have researched the psychophysiological response and energy balance of athletes in numerous ultraendurance probes, but none has investigated an ultraendurance mountain running event. The current study aims to analyze changes in blood lactate concentration, rating of perceived exertion, heart rate, heart rate variability, and energy balance after the performance of an ultraendurance mountain running event. The parameters in the 6 participants who finished the event were analyzed (age, 30.8 ± 3.1 years; height, 176.2 ± 8.6 cm; body mass, 69.2 ± 3.7 kg). The race covered 54 km, with 6441 m of altitude change, 3556 m downhill and 2885 m uphill. The athletes completed together the race in 14 h and 6 min. After the ultraendurance event, the athletes presented a negative energy balance of 4732 kcal, a blood lactate concentration of 2.8 ± 0.3 mmol/L, a heart rate mean/heart rate maximum ratio of 0.64, a heart rate mean of 111.4 ± 5.9 beats/min, a decrease in vagal modulation, and an increase in sympathetic modulation, and recorded 19.5 ± 1.5 points on the 6-20 rating of perceived exertion scale. The event was a stressful stimulus for the athletes despite the low intensity measured by blood lactate concentration and heart rate. The results obtained may be used by coaches as a reference parameter of heart rate, heart rate variability, rating of perceived exertion, and lactate concentration to develop specific training programs. In addition, the energy balance data obtained in this research may improve nutritional intake strategies. PMID:25693897

  2. Multi-scale Modeling of Energy Balance Fluxes in a Dense Tamarisk Riparian Forest

    NASA Astrophysics Data System (ADS)

    Neale, C. M.; Santos, C. A.; Watts, D.; Osterberg, J.; Hipps, L. E.; Sritharan, S. I.

    2008-12-01

    Remote sensing of energy balance fluxes has become operationally more viable over the last 10 years with the development of more robust multi-layer models and the availability of quasi-real time satellite imagery from most sensors. Riparian corridors in semi-arid and arid areas present a challenge to satellite based techniques for estimating evapotranspiration due to issues of scale and pixel resolution, especially when using the thermal infrared bands. This paper will present energy balance measurement and modeling results over a Salt Cedar (Tamarix Ramosissima) forest in the Cibola National Wildlife Refuge along the Colorado River south of Blythe, CA. The research site encompasses a 600 hectare area populated by mostly Tamarisk stands of varying density. Three Bowen ratio systems are installed on tall towers within varying densities of forest cover in the upwind footprint and growing under varying depths to the water table. An additional eddy covariance tower is installed alongside a Bowen ratio system on one of the towers. Flux data has been gathered continuously since early 2007. In the summer of 2007, a Scintec large aperture scintillometer was installed between two of the towers over 1 km apart and has been working continuously along with the flux towers. Two intensive field campaigns were organized in June 2007 and May 2008 to coincide with LANDSAT TM5, MODIS and ASTER overpasses. High resolution multispectral and thermal imagery was acquired at the same time with the USU airborne system to provide information for the up- scaling of the energy balance fluxes from tower to satellite scales. The paper will present comparisons between the different energy balance measuring techniques under the highly advective conditions of the experimental site, concentrating on the scintillometer data. Preliminary results of remotely sensed modeling of the fluxes at different scales and model complexity will also be presented.

  3. Energy Balance and Power Performance Analysis for Satellite in Low Earth Orbit

    NASA Astrophysics Data System (ADS)

    Jang, Sung-Soo; Kim, Sung-Hoon; Lee, Sang-Ryool; Choi, Jaeho

    2010-09-01

    The electrical power system (EPS) of Korean satellites in low-earth-orbit is designed to achieve energy balance based on a one-orbit mission scenario. This means that the battery has to be fully charged at the end of a one-orbit mission. To provide the maximum solar array (SA) power generation, the peak power tracking (PPT) method has been developed for a spacecraft power system. The PPT is operated by a software algorithm, which tracks the peak power of the SA and ensures the battery is fully charged in one orbit. The EPS should be designed to avoid the stress of electronics in order to handle the main bus power from the SA power. This paper summarizes the results of energy balance to achieve optimal power sizing and the actual trend analysis of EPS performance in orbit. It describes the results of required power for the satellite operation in the worst power conditions at the end-of-life, the methods and input data used in the energy balance, and the case study of energy balance analyses for the normal operation in orbit. Both 10:35 AM and 10:50 AM crossing times are considered, so the power performance in each case is analyzed with the satellite roll maneuver according to the payload operation concept. In addition, the data transmission to the Korea Ground Station during eclipse is investigated at the local-time-ascending-node of 11:00 AM to assess the greatest battery depth-of-discharge in normal operation.

  4. Breakfast and exercise contingently affect postprandial metabolism and energy balance in physically active males.

    PubMed

    Gonzalez, Javier T; Veasey, Rachel C; Rumbold, Penny L S; Stevenson, Emma J

    2013-08-01

    The present study examined the impact of breakfast and exercise on postprandial metabolism, appetite and macronutrient balance. A sample of twelve (blood variables n 11) physically active males completed four trials in a randomised, crossover design comprising a continued overnight fast followed by: (1) rest without breakfast (FR); (2) exercise without breakfast (FE); (3) breakfast consumption (1859 kJ) followed by rest (BR); (4) breakfast consumption followed by exercise (BE). Exercise was continuous, moderate-intensity running (expending approximately 2·9 MJ of energy). The equivalent time was spent sitting during resting trials. A test drink (1500 kJ) was ingested on all trials followed 90 min later by an ad libitum lunch. The difference between the BR and FR trials in blood glucose time-averaged AUC following test drink consumption approached significance (BR: 4·33 (SEM 0·14) v. FR: 4·75 (SEM 0·16) mmol/l; P=0·08); but it was not different between FR and FE (FE: 4·77 (SEM 0·14) mmol/l; P=0·65); and was greater in BE (BE: 4·97 (SEM 0·13) mmol/l) v. BR (P=0·012). Appetite following the test drink was reduced in BR v. FR (P=0·006) and in BE v. FE (P=0·029). Following lunch, the most positive energy balance was observed in BR and least positive in FE. Regardless of breakfast, acute exercise produced a less positive energy balance following ad libitum lunch consumption. Energy and fat balance is further reduced with breakfast omission. Breakfast improved the overall appetite responses to foods consumed later in the day, but abrogated the appetite-suppressive effect of exercise. PMID:23340006

  5. A role for central nervous system PPAR-γ in the regulation of energy balance.

    PubMed

    Ryan, Karen K; Li, Bailing; Grayson, Bernadette E; Matter, Emily K; Woods, Stephen C; Seeley, Randy J

    2011-05-01

    The peroxisome proliferator-activated receptor-γ (PPAR-γ) is a nuclear receptor that is activated by lipids to induce the expression of genes involved in lipid and glucose metabolism, thereby converting nutritional signals into metabolic consequences. PPAR-γ is the target of the thiazolidinedione (TZD) class of insulin-sensitizing drugs, which have been widely prescribed to treat type 2 diabetes mellitus. A common side effect of treatment with TZDs is weight gain. Here we report a previously unknown role for central nervous system (CNS) PPAR-γ in the regulation of energy balance. We found that both acute and chronic activation of CNS PPAR-γ, by either TZDs or hypothalamic overexpression of a fusion protein consisting of PPAR-γ and the viral transcriptional activator VP16 (VP16-PPAR-γ), led to positive energy balance in rats. Blocking the endogenous activation of CNS PPAR-γ with pharmacological antagonists or reducing its expression with shRNA led to negative energy balance, restored leptin sensitivity in high-fat-diet (HFD)-fed rats and blocked the hyperphagic response to oral TZD treatment. These findings have implications for the widespread clinical use of TZD drugs and for understanding the etiology of diet-induced obesity. PMID:21532595

  6. Using a biocultural approach to examine migration/globalization, diet quality, and energy balance.

    PubMed

    Himmelgreen, David A; Cantor, Allison; Arias, Sara; Romero Daza, Nancy

    2014-07-01

    The aim of this paper is to examine the role and impact that globalization and migration (e.g., intra-/intercontinental, urban/rural, and circular) have had on diet patterns, diet quality, and energy balance as reported on in the literature during the last 20 years. Published literature from the fields of anthropology, public health, nutrition, and other disciplines (e.g., economics) was collected and reviewed. In addition, case studies from the authors' own research are presented in order to elaborate on key points and dietary trends identified in the literature. While this review is not intended to be comprehensive, the findings suggest that the effects of migration and globalization on diet quality and energy balance are neither lineal nor direct, and that the role of social and physical environments, culture, social organization, and technology must be taken into account to better understand this relationship. Moreover, concepts such as acculturation and the nutrition transition do not necessarily explain or adequately describe all of the global processes that shape diet quality and energy balance. Theories from nutritional anthropology and critical bio-cultural medical anthropology are used to tease out some of these complex interrelationships. PMID:24463063

  7. Balancing Energy Consumption with Hybrid Clustering and Routing Strategy in Wireless Sensor Networks †

    PubMed Central

    Xu, Zhezhuang; Chen, Liquan; Liu, Ting; Cao, Lianyang; Chen, Cailian

    2015-01-01

    Multi-hop data collection in wireless sensor networks (WSNs) is a challenge issue due to the limited energy resource and transmission range of wireless sensors. The hybrid clustering and routing (HCR) strategy has provided an effective solution, which can generate a connected and efficient cluster-based topology for multi-hop data collection in WSNs. However, it suffers from imbalanced energy consumption, which results in the poor performance of the network lifetime. In this paper, we evaluate the energy consumption of HCR and discover an important result: the imbalanced energy consumption generally appears in gradient k=1, i.e., the nodes that can communicate with the sink directly. Based on this observation, we propose a new protocol called HCR-1, which includes the adaptive relay selection and tunable cost functions to balance the energy consumption. The guideline of setting the parameters in HCR-1 is provided based on simulations. The analytical and numerical results prove that, with minor modification of the topology in gradient k=1, the HCR-1 protocol effectively balances the energy consumption and prolongs the network lifetime. PMID:26492248

  8. Hypothalamic AMPK: a canonical regulator of whole-body energy balance.

    PubMed

    López, Miguel; Nogueiras, Rubén; Tena-Sempere, Manuel; Diéguez, Carlos

    2016-07-01

    AMP-activated protein kinase (AMPK) has a major role in the modulation of energy balance. AMPK is activated in conditions of low energy, increasing energy production and reducing energy consumption. The AMPK pathway is a canonical route regulating energy homeostasis by integrating peripheral signals, such as hormones and metabolites, with neuronal networks. Current evidence has implicated AMPK in the hypothalamus and hindbrain with feeding, brown adipose tissue thermogenesis and browning of white adipose tissue, through modulation of the sympathetic nervous system, as well as glucose homeostasis. Interestingly, several potential antiobesity and/or antidiabetic agents, some of which are currently in clinical use such as metformin and liraglutide, exert some of their actions by acting on AMPK. Furthermore, the orexigenic and weight-gain effects of commonly used antipsychotic drugs are also mediated by hypothalamic AMPK. Overall, this evidence suggests that hypothalamic AMPK signalling is an interesting target for drug development, but is this approach feasible? In this Review we discuss the current understanding of hypothalamic AMPK and its role in the central regulation of energy balance and metabolism. PMID:27199291

  9. An energy balance perspective on regional CO2-induced temperature changes in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Räisänen, Jouni

    2016-08-01

    An energy balance decomposition of temperature changes is conducted for idealized transient CO2-only simulations in the fifth phase of the Coupled Model Intercomparison Project. The multimodel global mean warming is dominated by enhanced clear-sky greenhouse effect due to increased CO2 and water vapour, but other components of the energy balance substantially modify the geographical and seasonal patterns of the change. Changes in the net surface energy flux are important over the oceans, being especially crucial for the muted warming over the northern North Atlantic and for the seasonal cycle of warming over the Arctic Ocean. Changes in atmospheric energy flux convergence tend to smooth the gradients of temperature change and reduce its land-sea contrast, but they also amplify the seasonal cycle of warming in northern North America and Eurasia. The three most important terms for intermodel differences in warming are the changes in the clear-sky greenhouse effect, clouds, and the net surface energy flux, making the largest contribution to the standard deviation of annual mean temperature change in 34, 29 and 20 % of the world, respectively. Changes in atmospheric energy flux convergence mostly damp intermodel variations of temperature change especially over the oceans. However, the opposite is true for example in Greenland and Antarctica, where the warming appears to be substantially controlled by heat transport from the surrounding sea areas.

  10. The global land surface energy balance and its representation in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Folini, Doris; Hakuba, Maria; Schär, Christoph; Seneviratne, Sonia; Kato, Seiji; Rutan, David; Ammann, Christof; Wood, Eric; König-Langlo, Gert

    2015-04-01

    The energy budget over terrestrial surfaces is a key determinant of the land surface climate and governs a variety of physical, chemical and biological surface processes. The purpose of the present study is to establish new reference estimates for the different components of the energy balance over global land surfaces. Thanks to the impressive progress in space-based observation systems in the past decade, we now know the energy exchanges between our planet and the surrounding space with unprecedented accuracy. However, the energy flows at the Earth's surface have not been established with the same accuracy, since they cannot be directly measured from satellites. Accordingly, estimates on the magnitude of the fluxes at terrestrial surfaces largely vary, and latest climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) still show significant differences in their simulated energy budgets on a land mean basis, which prevents a consistent simulation of the land surface processes in these models. In the present study we use to the extent possible direct observations of surface radiative fluxes from the Global Energy Balance Archive (GEBA) and the Baseline Surface Radiation Network (BSRN) to better constrain the simulated fluxes over global land surfaces. These model-calculated fluxes stem from the comprehensive set of more than 40 global climate from CMIP5 used in the latest IPCC report AR5. The CMIP5 models overall still show a tendency to overestimate the downward solar and underestimate the downward thermal radiation at terrestrial surfaces, a long standing problem in climate modelling. Based on the direct radiation observations and the bias structure of the CMIP5 models we infer best estimates for the downward solar and thermal radiation averaged over global land surfaces. They amount to 184 Wm-2 and 306 Wm-2, respectively. These values closely agree with the respective quantities independently derived by recent state-of-the-art reanalyses

  11. Combining Flux Balance and Energy Balance Analysis for Large-Scale Metabolic Network: Biochemical Circuit Theory for Analysis of Large-Scale Metabolic Networks

    NASA Technical Reports Server (NTRS)

    Beard, Daniel A.; Liang, Shou-Dan; Qian, Hong; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Predicting behavior of large-scale biochemical metabolic networks represents one of the greatest challenges of bioinformatics and computational biology. Approaches, such as flux balance analysis (FBA), that account for the known stoichiometry of the reaction network while avoiding implementation of detailed reaction kinetics are perhaps the most promising tools for the analysis of large complex networks. As a step towards building a complete theory of biochemical circuit analysis, we introduce energy balance analysis (EBA), which compliments the FBA approach by introducing fundamental constraints based on the first and second laws of thermodynamics. Fluxes obtained with EBA are thermodynamically feasible and provide valuable insight into the activation and suppression of biochemical pathways.

  12. Harmonic balance analysis of nonlinear tristable energy harvesters for performance enhancement

    NASA Astrophysics Data System (ADS)

    Zhou, Shengxi; Cao, Junyi; Inman, Daniel J.; Lin, Jing; Li, Dan

    2016-07-01

    Nonlinear energy harvesters are very sensitive to ambient vibrations. If the excitation level is too low, their large-amplitude oscillations for high-energy voltage output cannot be obtained. A nonlinear tristable energy harvester has been previously proposed to achieve more effective broadband energy harvesting for low-level excitations. However, the sensitivity of its dynamic characteristics to the system parameters remains uninvestigated. Therefore, this paper theoretically analyzes the influence of the external load, the external excitation, the internal system parameters and the equilibrium positions on the dynamic responses of nonlinear tristable energy harvesters by using the harmonic balance method. In addition, numerical acceleration excitation thresholds and basins of attraction are provided to investigate the potential for energy harvesting performance enhancement using the suitable equilibrium positions, appropriate initial conditions or external disturbances, due to high-energy interwell oscillations in the multi-solution ranges. More importantly, experimental voltage responses of a given tristable energy harvester versus the external excitation frequency and amplitude verify the existence of experimental multi-solution ranges and the effectiveness of the theoretical analysis. It is also revealed that achieving high-energy interwell oscillations in the multi-solution ranges of tristable energy harvesters will be feasible for improving energy harvesting from low-level ambient excitations.

  13. Master runners dominate 24-h ultramarathons worldwide—a retrospective data analysis from 1998 to 2011

    PubMed Central

    2013-01-01

    Background The aims of the present study were to examine (a) participation and performance trends and (b) the age of peak running performance in master athletes competing in 24-h ultra-marathons held worldwide between 1998 and 2011. Methods Changes in both running speed and the age of peak running speed in 24-h master ultra-marathoners (39,664 finishers, including 8,013 women and 31,651 men) were analyzed. Results The number of 24-h ultra-marathoners increased for both women and men across years (P < 0.01). The age of the annual fastest woman decreased from 48 years in 1998 to 35 years in 2011. The age of peaking running speed remained unchanged across time at 42.5 ± 5.2 years for the annual fastest men (P > 0.05). The age of the annual top ten women decreased from 42.6 ± 5.9 years (1998) to 40.1 ± 7.0 years (2011) (P < 0.01). For the annual top ten men, the age of peak running speed remained unchanged at 42 ± 2 years (P > 0.05). Running speed remained unchanged over time at 11.4 ± 0.4 km h-1 for the annual fastest men and 10.0 ± 0.2 km/h for the annual fastest women, respectively (P > 0.05). For the annual ten fastest women, running speed increased over time by 3.2% from 9.3 ± 0.3 to 9.6 ± 0.3 km/h (P < 0.01). Running speed of the annual top ten men remained unchanged at 10.8 ± 0.3 km/h (P > 0.05). Women in age groups 25–29 (r2 = 0.61, P < 0.01), 30–34 (r2 = 0.48, P < 0.01), 35–39 (r2 = 0.42, P = 0.01), 40–44 (r2 = 0.46, P < 0.01), 55–59 (r2 = 0.41, P = 0.03), and 60–64 (r2 = 0.57, P < 0.01) improved running speed; while women in age groups 45–49 and 50–54 maintained running speed (P > 0.05). Men improved running speed in age groups 25–29 (r2 = 0.48, P = 0.02), 45–49 (r2 = 0.34, P = 0.03), 50–54 (r2 = 0.50, P < 0.01), 55–59 (r2 = 0.70, P < 0.01), and 60–64 (r2 = 0.44, P = 0.03); while runners in age groups 30–34, 35–39, and 40–44 maintained running speed (P > 0.05). Conclusions Female and male age group runners improved

  14. Using multilevel path analysis in analyzing 24-h ambulatory physiological recordings applied to medically unexplained symptoms.

    PubMed

    Houtveen, Jan H; Hamaker, Ellen L; Van Doornen, Lorenz J P

    2010-05-01

    A non-clinical group high on heterogeneous medically unexplained symptoms (MUS; n=97) was compared with healthy controls (n=66) on the within-subject relationships between physiological measures using multilevel path analysis. Momentary experienced somatic complaints, mood (tension and depression), cardiac autonomic activity (inter-beat intervals, pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA)) and respiration (rate and partial pressure of CO(2) at the end of a normal expiration) were monitored for 24 h using electronic diary and ambulatory devices. Relationships between measures were controlled for diurnal variation and individual means. Only subtle group differences were found in the diurnal rhythm and in the within-subject relationships between physiological measures. For participants high on MUS, within-subject changes in bodily symptoms were related to changes in mood, but only marginally to the physiological measures. Results of the current path analysis confirm the subordinate role of cardiac autonomic and respiratory parameters in MUS. PMID:20030762

  15. Inter-comparison of energy balance and hydrological models for land surface energy flux estimation over a whole river catchment

    NASA Astrophysics Data System (ADS)

    Guzinski, R.; Nieto, H.; Stisen, S.; Fensholt, R.

    2015-04-01

    Evapotranspiration (ET) is the main link between the natural water cycle and the land surface energy budget. Therefore water-balance and energy-balance approaches are two of the main methodologies for modelling this process. The water-balance approach is usually implemented as a complex, distributed hydrological model, while the energy-balance approach is often used with remotely sensed observations of, for example, the land surface temperature (LST) and the state of the vegetation. In this study we compare the catchment-scale output of two remote sensing models based on the two-source energy-balance (TSEB) scheme, against a hydrological model, MIKE SHE, calibrated over the Skjern river catchment in western Denmark. The three models utilize different primary inputs to estimate ET (LST from different satellites in the case of remote sensing models and modelled soil moisture and heat flux in the case of the MIKE SHE ET module). However, all three of them use the same ancillary data (meteorological measurements, land cover type and leaf area index, etc.) and produce output at similar spatial resolution (1 km for the TSEB models, 500 m for MIKE SHE). The comparison is performed on the spatial patterns of the fluxes present within the catchment area as well as on temporal patterns on the whole catchment scale in 8-year long time series. The results show that the spatial patterns of latent heat flux produced by the remote sensing models are more similar to each other than to the fluxes produced by MIKE SHE. The temporal patterns produced by the remote sensing and hydrological models are quite highly correlated (r ≈ 0.8). This indicates potential benefits to the hydrological modelling community of integrating spatial information derived through remote sensing methodology (contained in the ET maps derived with the energy-balance models, satellite based LST or another source) into the hydrological models. How this could be achieved and how to evaluate the improvements, or

  16. Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans.

    PubMed

    Wright, K P; Hughes, R J; Kronauer, R E; Dijk, D J; Czeisler, C A

    2001-11-20

    Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis and for the proper timing of species-specific behaviors. We studied subjects in the laboratory for up to 55 days each to determine the ability to entrain the human clock to a weak circadian synchronizing stimulus [scheduled activity-rest cycle in very dim (approximately 1.5 lux in the angle of gaze) light-dark cycle] at three approximately 24-h periods: 23.5, 24.0, and 24.6 h. These studies allowed us to test two competing hypotheses as to whether the period of the human circadian pacemaker is near to or much longer than 24 h. We report here that imposition of a sleep-wake schedule with exposure to the equivalent of candle light during wakefulness and darkness during sleep is usually sufficient to maintain circadian entrainment to the 24-h day but not to a 23.5- or 24.6-h day. Our results demonstrate functionally that, in normally entrained sighted adults, the average intrinsic circadian period of the human biological clock is very close to 24 h. Either exposure to very dim light and/or the scheduled sleep-wake cycle itself can entrain this near-24-h intrinsic period of the human circadian pacemaker to the 24-h day. PMID:11717461

  17. Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans

    NASA Technical Reports Server (NTRS)

    Wright, K. P. Jr; Hughes, R. J.; Kronauer, R. E.; Dijk, D. J.; Czeisler, C. A.

    2001-01-01

    Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis and for the proper timing of species-specific behaviors. We studied subjects in the laboratory for up to 55 days each to determine the ability to entrain the human clock to a weak circadian synchronizing stimulus [scheduled activity-rest cycle in very dim (approximately 1.5 lux in the angle of gaze) light-dark cycle] at three approximately 24-h periods: 23.5, 24.0, and 24.6 h. These studies allowed us to test two competing hypotheses as to whether the period of the human circadian pacemaker is near to or much longer than 24 h. We report here that imposition of a sleep-wake schedule with exposure to the equivalent of candle light during wakefulness and darkness during sleep is usually sufficient to maintain circadian entrainment to the 24-h day but not to a 23.5- or 24.6-h day. Our results demonstrate functionally that, in normally entrained sighted adults, the average intrinsic circadian period of the human biological clock is very close to 24 h. Either exposure to very dim light and/or the scheduled sleep-wake cycle itself can entrain this near-24-h intrinsic period of the human circadian pacemaker to the 24-h day.

  18. 24-h activity rhythm and sleep in depressed outpatients.

    PubMed

    Hori, Hiroaki; Koga, Norie; Hidese, Shinsuke; Nagashima, Anna; Kim, Yoshiharu; Higuchi, Teruhiko; Kunugi, Hiroshi

    2016-06-01

    Disturbances in sleep and circadian rest-activity rhythms are key features of depression. Actigraphy, a non-invasive method for monitoring motor activity, can be used to objectively assess circadian rest-activity rhythms and sleep patterns. While recent studies have measured sleep and daytime activity of depressed patients using wrist-worn actigraphy, the actigraphic 24-h rest-activity rhythm in depression has not been well documented. We aimed to examine actigraphically measured sleep and circadian rest-activity rhythms in depressed outpatients. Twenty patients with DSM-IV major depressive episode and 20 age- and sex-matched healthy controls participated in this study. Participants completed 7 consecutive days of all-day actigraphic activity monitoring while engaging in usual activities. For sleep parameters, total sleep time, wake after sleep onset, and sleep fragmentation index were determined. Circadian rhythms were estimated by fitting individual actigraphy data to a cosine curve of a 24-h activity rhythm using the cosinor method, which generated three circadian activity rhythm parameters, i.e., MESOR (rhythm-adjusted mean), amplitude, and acrophase. Subjective sleep was also assessed using a sleep diary and the Pittsburgh Sleep Quality Index. Patients showed significantly lower MESOR and more dampened amplitude along with significant sleep disturbances. Logistic regression analysis revealed that lower MESOR and more fragmented sleep emerged as the significant predictors of depression. Correlations between subjectively and actigraphically measured parameters demonstrated the validity of actigraphic measurements. These results indicate marked disturbances in sleep and circadian rest-activity rhythms of depression. By simultaneously measuring sleep and rest-activity rhythm parameters, actigraphy might serve as an objective diagnostic aid for depression. PMID:26978182

  19. Measurement of body composition as a surrogate evaluation of energy balance in obese patients.

    PubMed

    Rotella, Carlo Maria; Dicembrini, Ilaria

    2015-03-26

    In clinical practice obesity is primarily diagnosed through the body mass index. In order to characterize patients affected by obesity the use of traditional anthropometric measures appears misleading. Beyond the body mass index, there are overwhelming evidences towards the relevance of a more detailed description of the individual phenotype by characterizing the main body components as free-fat mass, muscle mass, and fat mass. Among the numerous techniques actually available, bioelectrical impedance analysis seems to be the most suitable in a clinical setting because it is simple, inexpensive, noninvasive, and highly reproducible. To date, there is no consensus concerning the use of one preferred equation for the resting energy expenditure in overweight and/or obese population. Energy restriction alone is an effective strategy to achieve an early and significant weight loss, however it results in a reduction of both fat and lean mass therefore promoting or aggravating an unfavourable body composition (as sarcobesity) in terms of mortality and comorbidities. Therefore the implementation of daily levels of physical activity should be simultaneously promoted. The major role of muscle mass in the energy balance has been recently established by the rising prevalence of the combination of two condition as sarcopenia and obesity. Physical exercise stimulates energy expenditure, thereby directly improving energy balance, and also promotes adaptations such as fiber type, mitochondrial biogenesis, improvement of insulin resistance, and release of myokines, which may influence different tissues, including muscle. PMID:25825693

  20. Measurement of body composition as a surrogate evaluation of energy balance in obese patients

    PubMed Central

    Rotella, Carlo Maria; Dicembrini, Ilaria

    2015-01-01

    In clinical practice obesity is primarily diagnosed through the body mass index. In order to characterize patients affected by obesity the use of traditional anthropometric measures appears misleading. Beyond the body mass index, there are overwhelming evidences towards the relevance of a more detailed description of the individual phenotype by characterizing the main body components as free-fat mass, muscle mass, and fat mass. Among the numerous techniques actually available, bioelectrical impedance analysis seems to be the most suitable in a clinical setting because it is simple, inexpensive, noninvasive, and highly reproducible. To date, there is no consensus concerning the use of one preferred equation for the resting energy expenditure in overweight and/or obese population. Energy restriction alone is an effective strategy to achieve an early and significant weight loss, however it results in a reduction of both fat and lean mass therefore promoting or aggravating an unfavourable body composition (as sarcobesity) in terms of mortality and comorbidities. Therefore the implementation of daily levels of physical activity should be simultaneously promoted. The major role of muscle mass in the energy balance has been recently established by the rising prevalence of the combination of two condition as sarcopenia and obesity. Physical exercise stimulates energy expenditure, thereby directly improving energy balance, and also promotes adaptations such as fiber type, mitochondrial biogenesis, improvement of insulin resistance, and release of myokines, which may influence different tissues, including muscle. PMID:25825693

  1. Energy balance in olive oil farms: comparison of organic and conventional farming systems.

    NASA Astrophysics Data System (ADS)

    Moreno, Marta M.; Meco, Ramón; Moreno, Carmen

    2013-04-01

    The viability of an agricultural production system not only depends on the crop yields, but especially on the efficient use of available resources. However, the current agricultural systems depend heavily on non-renewable energy consumption in the form of fertilizers, fossil fuels, pesticides and machinery. In developed countries, the economic profitability of different productive systems is dependent on the granting of subsidies of diverse origin that affect both production factors (or inputs) and the final product (or output). Leaving such external aids, energy balance analysis reveals the real and most efficient form of management for each agroclimatic region, and is also directly related to the economic activity and the environmental state. In this work we compare the energy balance resulting from organic and conventional olive oil farms under the semi-arid conditions of Central Spain. The results indicate that the mean energy supplied to the organic farms was sensitively lower (about 30%) in comparison with the conventional management, and these differences were more pronounced for the biggest farms (> 15 ha). Mean energy outputs were about 20% lower in the organic system, although organic small farms (< 15 ha) resulted more productive than the conventional small ones. However, these lower outputs were compensated by the major market value obtained from the organic products. Chemical fertilizers and pesticides reached about 60% of the total energy inputs in conventional farming; in the organic farms, however, this ratio scarcely reached 25%. Human labor item only represented a very small amount of the total energy input in both cases (less than 1%). As conclusions, both management systems were efficient from an energy point of view. The value of the organic production should be focused on the environmental benefits it provides, which are not usually considered in the conventional management on not valuing the damage it produces to the environment. Organic

  2. HERschel Observations of Edge-on Spirals (HEROES). III. Dust energy balance study of IC 2531

    NASA Astrophysics Data System (ADS)

    Mosenkov, Aleksandr V.; Allaert, Flor; Baes, Maarten; Bianchi, Simone; Camps, Peter; De Geyter, Gert; De Looze, Ilse; Fritz, Jacopo; Gentile, Gianfranco; Hughes, Thomas M.; Lewis, Fraser; Verstappen, Joris; Verstocken, Sam; Viaene, Sébastien

    2016-07-01

    We investigate the dust energy balance for the edge-on galaxy IC 2531, one of the seven galaxies in the HEROES sample. We perform a state-of-the-art radiative transfer modelling based, for the first time, on a set of optical and near-infrared galaxy images. We show that by taking into account near-infrared imaging in the modelling significantly improves the constraints on the retrieved parameters of the dust content. We confirm the result from previous studies that including a young stellar population in the modelling is important to explain the observed stellar energy distribution. However, the discrepancy between the observed and modelled thermal emission at far-infrared wavelengths, the so-called dust energy balance problem, is still present: the model underestimates the observed fluxes by a factor of about two. We compare two different dust models, and find that dust parameters, and thus the spectral energy distribution in the infrared domain, are sensitive to the adopted dust model. In general, the THEMIS model reproduces the observed emission in the infrared wavelength domain better than the popular BARE-GR-S model. Our study of IC 2531 is a pilot case for detailed and uniform radiative transfer modelling of the entire HEROES sample, which will shed more light on the strength and origins of the dust energy balance problem. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.The reduced images (as FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A71

  3. Calcium, dairy products, and energy balance in overweight adolescents: a controlled trial1234

    PubMed Central

    Campbell, Wayne W; Teegarden, Dorothy; Craig, Bruce A; Martin, Berdine R; Singh, Rajni; Braun, Michelle M; Apolzan, John W; Hannon, Tamara S; Schoeller, Dale A; DiMeglio, Linda A; Hickey, Yvonne; Peacock, Munro

    2011-01-01

    Background: Dairy product and calcium consumption have been associated with modifying body fat and body weight in children and adults. Objective: In overweight adolescent boys and girls, we aimed to determine the effect of the doubling of habitual calcium intake to the recommended intake from dairy or calcium carbonate on energy balance and purported mechanisms including fecal fat excretion, macronutrient use, and parathyroid hormone suppression. Design: Twenty-five girls with a mean (±SD) BMI (in kg/m2) of 33 ± 5 and 17 boys with a BMI of 28 ± 5, aged 12–15 y, participated in two 3-wk controlled feeding sessions that used a crossover design in random order as a summer research camp. In one session, 756 mg Ca/d was consumed; in the other session, an additional 650 mg Ca/d was provided as dairy or calcium carbonate supplements that were matched to the control in macronutrient content. Total energy and macronutrient intakes were controlled and were the same for the 2 sessions for each subject. Primary outcome measures were energy balance, fecal fat excretion, lipid oxidation, and postprandial energy expenditure. Results: There were no effects of quantity or source of calcium on energy or fat balance, despite calcium-induced increases (P <0.01) in postprandial serum parathyroid hormone suppression. Conclusion: These data lend little evidence to support the proposed mechanisms for the relation between an increase in calcium intake from calcium carbonate or dairy and weight loss or weight maintenance in children. This trial was registered at clinicaltrials.gov as NCT00592137. PMID:21918216

  4. The relevance of rooftops: Analyzing the microscale surface energy balance in the Chicago region

    NASA Astrophysics Data System (ADS)

    Khosla, Radhika

    Spatial structure in climate variables often exist over very short length scales within an urban area, and this structure is a result of various site-specific features. In order to analyze the seasonal and diurnal energy flows that take place at a microclimatic surface, this work develops a semi-empirical energy balance model. For this, radiation fluxes and meteorological measurements are determined by direct observation; sensible heat and latent heat fluxes by parameterizations; and the heat storage flux by a 1-D mechanistic model that allows analysis of the temperature profile and heat storage within an underlying slab. Two sites receive detailed study: an anthropogenic site, being a University of Chicago building rooftop, and a natural site, outside Chicago in the open country. Two identical sets of instruments record measurements contemporaneously from these locations during June-November 2007, the entire period for which analyses are carried out. The study yields seasonal trends in surface temperature, surface-to-air temperature contrast and net radiation. At both sites, a temporal hysteresis between net radiation and heat storage flux indicates that surplus energy absorbed during daylight is released to the atmosphere later in the evening. The surface energy balance model responds well to site specific features for both locations. An analysis of the surface energy balance shows that the flux of sensible heat is the largest non-radiative contributor to the roof's surface cooling, while the flux of latent heat (also referred to as evaporative cooling) is the largest heat sink for the soil layer. In the latter part of the study, the surface energy balance model is upgraded by adding the capability to compute changes in surface temperature and non-radiative fluxes for any specified set of thermal and reflective roof properties. The results of this analysis allow an examination of the relationship between the roof temperature, the heat flux entering the building

  5. Zarya Energy Balance Analysis: The Effect of Spacecraft Shadowing on Solar Array Performance

    NASA Technical Reports Server (NTRS)

    Hoffman, David J.; Kolosov, Vladimir

    1999-01-01

    The first element of the International Space Station (ISS). Zarya, was funded by NASA and built by the Russian aerospace company Khrunichev State Research and Production Space Center (KhSC). NASA Glenn Research Center (GRC) and KhSC collaborated in performing analytical predictions of the on-orbit electrical performance of Zarya's solar arrays. GRC assessed the pointing characteristics of and shadow patterns on Zarya's solar arrays to determine the average solar energy incident on the arrays. KHSC used the incident energy results to determine Zarya's electrical power generation capability and orbit-average power balance. The power balance analysis was performed over a range of solar beta angles and vehicle operational conditions. This analysis enabled identification of problems that could impact the power balance for specific flights during ISS assembly and was also used as the primary means of verifying that Zarya complied with electrical power requirements. Analytical results are presented for select stages in the ISS assembly sequence along with a discussion of the impact of shadowing on the electrical performance of Zarya's solar arrays.

  6. Combining flux and energy balance analysis to model large-scale biochemical networks.

    PubMed

    Heuett, William J; Qian, Hong

    2006-12-01

    Stoichiometric Network Theory is a constraints-based, optimization approach for quantitative analysis of the phenotypes of large-scale biochemical networks that avoids the use of detailed kinetics. This approach uses the reaction stoichiometric matrix in conjunction with constraints provided by flux balance and energy balance to guarantee mass conserved and thermodynamically allowable predictions. However, the flux and energy balance constraints have not been effectively applied simultaneously on the genome scale because optimization under the combined constraints is non-linear. In this paper, a sequential quadratic programming algorithm that solves the non-linear optimization problem is introduced. A simple example and the system of fermentation in Saccharomyces cerevisiae are used to illustrate the new method. The algorithm allows the use of non-linear objective functions. As a result, we suggest a novel optimization with respect to the heat dissipation rate of a system. We also emphasize the importance of incorporating interactions between a model network and its surroundings. PMID:17245812

  7. Global estimation of evapotranspiration using a leaf area index-based surface energy and water balance model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies of global hydrologic cycles, carbon cycles and climate change are greatly facilitated when global estimates of evapotranspiration (E) are available. We have developed an air-relative-humidity-based two-source (ARTS) E model that simulates the surface energy balance, soil water balance, and e...

  8. Two-source energy balance model evaluation for mapping evapotranspiration on the semi-arid Southern High Plains

    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. In this study, we applied the Two-Source Energy Balance (T-SEB) model to estimate hourly ET from the Landsat Thematic Mapper (TM) data for the semi-ar...

  9. Energy Balance, Evapo-transpiration and Dew deposition in the Dead Sea Valley

    NASA Astrophysics Data System (ADS)

    Metzger, Jutta; Corsmeier, Ulrich

    2016-04-01

    The Dead Sea is a unique place on earth. It is a terminal hypersaline lake, located at the lowest point on earth with a lake level of currently -429 m above mean sea level (amsl). It is located in a transition zone of semiarid to arid climate conditions, which makes it highly sensible to climate change (Alpert1997, Smiatek2011). The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric hydrological, and lithospheric processes in the changing environment of the Dead Sea. At the moment the most prominent environmental change is the lake level decline of approximately 1 m / year due to anthropogenic interferences (Gertman, 2002). This leads to noticeable changes in the fractions of the existing terrestrial surfaces - water, bare soil and vegetated areas - in the valley. Thus, the partitioning of the net radiation in the valley changes as well. To thoroughly study the atmospheric and hydrological processes in the Dead Sea valley, which are driven by the energy balance components, sound data of the energy fluxes of the different surfaces are necessary. Before DESERVE no long-term monitoring network simultaneously measuring the energy balance components of the different surfaces in the Dead Sea valley was available. Therefore, three energy balance stations were installed at three characteristic sites at the coast-line, over bare soil, and within vegetation, measuring all energy balance components by using the eddy covariance method. The results show, that the partitioning of the energy into sensible and latent heat flux on a diurnal scale is totally different at the three sites. This results in gradients between the sites, which are e.g. responsible for the typical diurnal wind systems at the Dead Sea. Furthermore, driving forces of evapo-transpiration at the sites were identified and a detailed analysis of the daily evaporation and dew deposition rates

  10. Analysis of climate change impacts on surface energy balance of Lake Huron (estimation of surface energy balance components: Remote sensing approach for water -- atmosphere parameterization)

    NASA Astrophysics Data System (ADS)

    Petchprayoon, Pakorn

    The purpose of this thesis was to investigate the physical processes of energy exchange between the water surface and atmosphere of Lake Huron in order to explain the processes behind such changes in long-term water levels and to monitor their spatial and temporal fluctuations. The lake surface water temperature and the four components of surface energy balance, including net radiation, latent heat, sensible heat, and heat storage, as well as evaporation rate, were estimated using the daily remotely sensed data from eleven years (2002--2012) with a multi-spatial resolution of 1 km to 5 km using the Moderate Resolution Imaging Spectroradiometer (MODIS) on board Terra satellite, together with in-situ measurements. The regression analysis of the entire lake daily mean water surface temperature revealed a positive trend of 0.1 °C per year, indicating that the lake surface temperature increased by 1.1°C during the period 2002-2012. The warming rate was found to be greatest in the deepest areas of the lake, with a statistically-significant correlation between warming rate and depth. The four components of surface energy balance showed temporal and spatial heterogeneities. There were strong seasonal patterns for all of the components, which were very high in summer and low in winter for net radiation and heat storage. In contrast, the latent heat and sensible heat were very high in the winter and very low in the summer. Approximately 70% of the annual mean 30 min evaporation occurred during the fall and winter seasons, whereas the lowest evaporation rate occurred in March, which was only 3% of the annual mean of 30 min evaporation. There was an increase in the evaporation rate of approximately 1.4 mm m-2 over the 2005--2012 observation period, the water level decreased by 0.04 m during the period 2002--2012, and there was a decrease in total water storage by 1.18 cm during the entire study period (2004--2012). There was obviously a negative correlation between lake

  11. Genetic Determinants of Atherosclerosis, Obesity and Energy Balance in Consomic Mice

    PubMed Central

    Spiezio, Sabrina H.; Amon, Lynn M.; McMillen, Timothy S.; Vick, Cynthia M.; Houston, Barbara A.; Caldwell, Mark; Ogimoto, Kayoko; Morton, Gregory J.; Kirk, Elizabeth A.; Schwartz, Michael W.; Nadeau, Joseph H.; LeBoeuf, Renée C.

    2014-01-01

    Metabolic diseases such as obesity and atherosclerosis result from complex interactions between environmental factors and genetic variants. A panel of chromosome substitution strains (CSSs) was developed to characterize genetic and dietary factors contributing to metabolic diseases and other biological traits and biomedical conditions. Our goal here was to identify quantitative trait loci (QTLs) contributing to obesity, energy expenditure and atherosclerosis. Parental strains C57BL/6 and A/J together with a panel of 21 CSSs derived from these progenitors were subjected to chronic feeding of rodent chow and atherosclerotic (females) or diabetogenic (males) test diets, and evaluated for a variety of metabolic phenotypes including several traits unique to this report, namely fat pad weights, energy balance and atherosclerosis. A total of 297 QTLs across 35 traits were discovered, two of which provided significant protection from atherosclerosis, and several dozen QTLs modulated body weight, body composition and circulating lipid levels in females and males. While several QTLs confirmed previous reports, most QTLs were novel. Finally, we applied the CSS quantitative genetic approach to energy balance, and identified three novel QTLs controlling energy expenditure and one QTL modulating food intake. Overall, we identified many new QTLs and phenotyped several novel traits in this mouse model of diet-induced metabolic diseases. PMID:25001233

  12. Genetic determinants of atherosclerosis, obesity, and energy balance in consomic mice.

    PubMed

    Spiezio, Sabrina H; Amon, Lynn M; McMillen, Timothy S; Vick, Cynthia M; Houston, Barbara A; Caldwell, Mark; Ogimoto, Kayoko; Morton, Gregory J; Kirk, Elizabeth A; Schwartz, Michael W; Nadeau, Joseph H; LeBoeuf, Renée C

    2014-12-01

    Metabolic diseases such as obesity and atherosclerosis result from complex interactions between environmental factors and genetic variants. A panel of chromosome substitution strains (CSSs) was developed to characterize genetic and dietary factors contributing to metabolic diseases and other biological traits and biomedical conditions. Our goal here was to identify quantitative trait loci (QTLs) contributing to obesity, energy expenditure, and atherosclerosis. Parental strains C57BL/6 and A/J together with a panel of 21 CSSs derived from these progenitors were subjected to chronic feeding of rodent chow and atherosclerotic (females) or diabetogenic (males) test diets, and evaluated for a variety of metabolic phenotypes including several traits unique to this report, namely fat pad weights, energy balance, and atherosclerosis. A total of 297 QTLs across 35 traits were discovered, two of which provided significant protection from atherosclerosis, and several dozen QTLs modulated body weight, body composition, and circulating lipid levels in females and males. While several QTLs confirmed previous reports, most QTLs were novel. Finally, we applied the CSS quantitative genetic approach to energy balance, and identified three novel QTLs controlling energy expenditure and one QTL modulating food intake. Overall, we identified many new QTLs and phenotyped several novel traits in this mouse model of diet-induced metabolic diseases. PMID:25001233

  13. Calculation Of A Micro Discharge Energy Balance With PIC-MCC Method

    SciTech Connect

    Benstaali, W.; Belasri, A.; Hagelaar, G. J. M.; Boeuf, J. P.

    2008-09-23

    In this paper, we present a 1D Particle in Cell with Monte Carlo Collisions model, developed in order to calculate the energy balance in a micro-discharge, under conditions similar to those of a Plasma Display Panel (PDP) cell. The discharge takes place in a xenon-neon (10%-;90%) mixture at 560 torr and for a gap length of 100 {mu}m. The model is used to analyze in details the energy deposition during the discharge pulse. The results show the amount of energy dissipated by ions (collisions in the gas and on the cathode), by electrons (excitation of the different electronic states, ionization), and their variations with the applied voltage. This model will be used in the future to test the approximations of the fluid models which are generally used to optimize PDP operating conditions, and to check whether or not fluid models can correctly predict the trends in the variations of the energy balance with parameters such as voltage, pressure, gas mixture.

  14. [Physiopathology of obesity. Dietary factors, and regulation of the energy balance].

    PubMed

    Ziegler, O; Quilliot, D; Guerci, B

    2000-12-01

    Energy balance and macronutrient balance are the cornerstones upon which any theories of obesity must be built. Obesity can only occur when energy intake remains higher than energy expenditure for an extended period of time. However the macronutrient composition of the diet can also affect energy balance. Fat is a key nutrient because it is poorly regulated at both the level of consumption and oxidation. Psychological and behavioural profiles of obese subjects are clearly important because they can affect food choice and eating patterns. The role of eating frequency and circadian distribution of food is still debated. Eating disorders could be implicated in the development of obesity, but it is uncertain whether obesity is a direct result or a cause of the eating disorder. There are strong evidence to suggest that dietary restraint is associated with loss of dietary control and excessive eating. Early stages of fat storage involve expansion of existing adipocytes (hypertrophy) and later stages involve the recruitment of new adipocytes (hyperplasia). The mechanisms controlling the transformation of preadipocyte could also involve specific dietary components such as polyunsaturated fatty acids or proteins. The age of adiposity rebound, that is a risk factor for later obesity has been found significantly younger in children consuming a high protein diet. These factors could be involved during early infancy or even in utero, according to the hypothesis of fetal programming of adult diseases. There is a need for more longitudinal studies on the role of macronutrient composition, food choice or eating disorders, especially among children, teenagers and young adults. PMID:11148332

  15. Regulation of energy balance by inflammation: common theme in physiology and pathology.

    PubMed

    Wang, Hui; Ye, Jianping

    2015-03-01

    Inflammation regulates energy metabolism in both physiological and pathological conditions. Pro-inflammatory cytokines involves in energy regulation in several conditions, such as obesity, aging (calorie restriction), sports (exercise), and cancer (cachexia). Here, we introduce a view of integrative physiology to understand pro-inflammatory cytokines in the control of energy expenditure. In obesity, chronic inflammation is derived from energy surplus that induces adipose tissue expansion and adipose tissue hypoxia. In addition to the detrimental effect on insulin sensitivity, pro-inflammatory cytokines also stimulate energy expenditure and facilitate adipose tissue remodeling. In caloric restriction (CR), inflammatory status is decreased by low energy intake that results in less energy supply to immune cells to favor energy saving under caloric restriction. During physical exercise, inflammatory status is elevated due to muscle production of pro-inflammatory cytokines, which promote fatty acid mobilization from adipose tissue to meet the muscle energy demand. In cancer cachexia, chronic inflammation is elevated by the immune response in the fight against cancer. The energy expenditure from chronic inflammation contributes to weight loss. Immune tolerant cancer cells gains more nutrients during the inflammation. In these conditions, inflammation coordinates energy distribution and energy demand between tissues. If the body lacks response to the pro-inflammatory cytokines (Inflammation Resistance), the energy metabolism will be impaired leading to an increased risk for obesity. In contrast, super-induction of the inflammation activity leads to weight loss and malnutrition in cancer cachexia. In summary, inflammation is a critical component in the maintenance of energy balance in the body. Literature is reviewed in above fields to support this view. PMID:25526866

  16. Evaluation of measured and simulated turbulent components of a snow cover energy balance model in order to refine the turbulent transfer algorithm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy balance models use physically based principles to simulate snow cover accumulation and melt. Snobal, a snow cover energy balance model, uses a flux-profile approach to calculating the turbulent flux (sensible and latent heat flux) components of the energy balance. Historically, validation dat...

  17. Reconnoitering the effect of shallow groundwater on land surface temperature and surface energy balance using MODIS and SEBS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The possibility of observing shallow groundwater depth and areal extent using satellite measurements can support groundwater models and vast irrigation systems management. Besides, these measurements help to integrate groundwater effects on surface energy balance within land surface models and clima...

  18. Tuberculosis in hospitalized patients: clinical characteristics of patients receiving treatment within the first 24 h after admission*

    PubMed Central

    Silva, Denise Rossato; da Silva, Larissa Pozzebon; Dalcin, Paulo de Tarso Roth

    2014-01-01

    Objective: To evaluate clinical characteristics and outcomes in patients hospitalized for tuberculosis, comparing those in whom tuberculosis treatment was started within the first 24 h after admission with those who did not. Methods: This was a retrospective cohort study involving new tuberculosis cases in patients aged ≥ 18 years who were hospitalized after seeking treatment in the emergency room. Results: We included 305 hospitalized patients, of whom 67 (22.0%) received tuberculosis treatment within the first 24 h after admission ( ≤24h group) and 238 (88.0%) did not (>24h group). Initiation of tuberculosis treatment within the first 24 h after admission was associated with being female (OR = 1.99; 95% CI: 1.06-3.74; p = 0.032) and with an AFB-positive spontaneous sputum smear (OR = 4.19; 95% CI: 1.94-9.00; p < 0.001). In the ≤24h and >24h groups, respectively, the ICU admission rate was 22.4% and 15.5% (p = 0.258); mechanical ventilation was used in 22.4% and 13.9% (p = 0.133); in-hospital mortality was 22.4% and 14.7% (p = 0.189); and a cure was achieved in 44.8% and 52.5% (p = 0.326). Conclusions: Although tuberculosis treatment was initiated promptly in a considerable proportion of the inpatients evaluated, the rates of in-hospital mortality, ICU admission, and mechanical ventilation use remained high. Strategies for the control of tuberculosis in primary care should consider that patients who seek medical attention at hospitals arrive too late and with advanced disease. It is therefore necessary to implement active surveillance measures in the community for earlier diagnosis and treatment. PMID:25029651

  19. Utilizing hydropower for load balancing non-storable renewable energy sources - technical and environmental challenges

    NASA Astrophysics Data System (ADS)

    Alfredsen, K. T.; Killingtveit, A.

    2011-12-01

    About 99% of the total energy production in Norway comes from hydropower, and the total production of about 120 TWh makes Norway Europe's largest hydropower producer. Most hydropower systems in Norway are based on high-head plants with mountain storage reservoirs and tunnels transporting water from the reservoirs to the power plants. In total, Norwegian reservoirs contributes around 50% of the total energy storage capacity in Europe. Current strategies to reduce emission of greenhouse gases from energy production involve increased focus on renewable energy sources, e.g. the European Union's 202020 goal in which renewable energy sources should be 20% of the total energy production by 2020. To meet this goal new renewable energy installations must be developed on a large scale in the coming years, and wind power is the main focus for new developments. Hydropower can contribute directly to increase renewable energy through new development or extensions to existing systems, but maybe even more important is the potential to use hydropower systems with storage for load balancing in a system with increased amount of non-storable renewable energies. Even if new storage technologies are under development, hydro storage is the only technology available on a large scale and the most economical feasible alternative. In this respect the Norwegian system has a high potential both through direct use of existing reservoirs and through an increased development of pump storage plants utilizing surplus wind energy to pump water and then producing during periods with low wind input. Through cables to Europe, Norwegian hydropower could also provide balance power for the North European market. Increased peaking and more variable operation of the current hydropower system will present a number of technical and environmental challenges that needs to be identified and mitigated. A more variable production will lead to fluctuating flow in receiving rivers and reservoirs, and it will also

  20. On the role of energy balance for numerical modeling of tsunami sediment transport

    NASA Astrophysics Data System (ADS)

    Sugawara, D.; Naruse, H.; Goto, K.

    2014-12-01

    Large-scale tsunamis in the shallow sea and on land are characterized by greater flow depth and speed than other natural open-channel flows. In-situ instrumental observation of tsunami sediment transport is practically impossible. Our understandings on the dynamics of tsunami sedimentation is mainly founded on the analysis of pre- and post-tsunami geomorphological data, field observation and laboratory analysis of tsunami deposits and modeling of tsunami sediment transport by means of hydraulic, mathematical and numerical approaches. Based on massive dataset of the 2011 Tohoku tsunami deposits, Goto et al. (in press) identified a possible upper threshold of tsunami sedimentation. They found that sediment concentration, which is defined as a ratio of deposit thickness to the local flow depth, can be approximated by a constant value of 2% over the coastal plain of the Sendai Bay, northeast Japan. Energy balance is an important physics to explain the upper threshold of tsunami sediment transport. The concept of energy constraint was described by Parker et al. (1986) for turbidity current. It declares the turbulent kinetic energy should be consumed to pick-up sediments from the bed and keep them in suspension. The loss of the turbulent energy results in decreased capacity of suspended load. Naruse et al. (2014) introduced the energy concept to tsunami sediment transport, and predicted the limiting sediment concentration of ~2% for a flow depth of 10 m and a flow speed of 10 m/s, which are typical for Sendai Plain. The role of energy constraint for tsunami sedimentation was also investigated using a numerical approach. The saturation concentration for wash load (Bagnold, 1962; van Rijn, 2007), which also accounts the energy balance, was implemented to a numerical model of tsunami sediment transport, and the model was applied to the case study of the 2011 Tohoku tsunami. The modeling result showed that the observed limiting concentration of 2% may be caused from flow

  1. Pyrolysis and gasification of meat-and-bone-meal: Energy balance and GHG accounting

    SciTech Connect

    Cascarosa, Esther; Boldrin, Alessio; Astrup, Thomas

    2013-11-15

    Highlights: • GHG savings are in the order of 600–1000 kg CO{sub 2}-eq. per Mg of MBM treated. • Energy recovery differed in terms of energy products and efficiencies. • The results were largely determined by use of the products for energy purposes. - Abstract: Meat-and-bone-meal (MBM) produced from animal waste has become an increasingly important residual fraction needing management. As biodegradable waste is routed away from landfills, thermo-chemical treatments of MBM are considered promising solution for the future. Pyrolysis and gasification of MBM were assessed based on data from three experimental lab and pilot-scale plants. Energy balances were established for the three technologies, providing different outcomes for energy recovery: bio-oil was the main product for the pyrolysis system, while syngas and a solid fraction of biochar were the main products in the gasification system. These products can be used – eventually after upgrading – for energy production, thereby offsetting energy production elsewhere in the system. Greenhouse gases (GHG) accounting of the technologies showed that all three options provided overall GHG savings in the order of 600–1000 kg CO{sub 2}-eq. per Mg of MBM treated, mainly as a consequence of avoided fossil fuel consumption in the energy sector. Local conditions influencing the environmental performance of the three systems were identified, together with critical factors to be considered during decision-making regarding MBM management.

  2. The analysis and kinetic energy balance of an upper-level wind maximum during intense convection

    NASA Technical Reports Server (NTRS)

    Fuelberg, H. E.; Jedlovec, G. J.

    1982-01-01

    The purpose of this paper is to analyze the formation and maintenance of the upper-level wind maximum which formed between 1800 and 2100 GMT, April 10, 1979, during the AVE-SESAME I period, when intense storms and tornadoes were experienced (the Red River Valley tornado outbreak). Radiosonde stations participating in AVE-SESAME I are plotted (centered on Oklahoma). National Meteorological Center radar summaries near the times of maximum convective activity are mapped, and height and isotach plots are given, where the formation of an upper-level wind maximum over Oklahoma is the most significant feature at 300 mb. The energy balance of the storm region is seen to change dramatically as the wind maximum forms. During much of its lifetime, the upper-level wind maximum is maintained by ageostrophic flow that produces cross-contour generation of kinetic energy and by the upward transport of midtropospheric energy. Two possible mechanisms for the ageostrophic flow are considered.

  3. Energy and water balance response of a vegetated wetland to herbicide treatment of invasive Phragmites australis

    NASA Astrophysics Data System (ADS)

    Mykleby, Phillip M.; Lenters, John D.; Cutrell, Gregory J.; Herrman, Kyle S.; Istanbulluoglu, Erkan; Scott, Durelle T.; Twine, Tracy E.; Kucharik, Christopher J.; Awada, Tala; Soylu, Mehmet E.; Dong, Bo

    2016-08-01

    The energy and water balance of a Phragmites australis dominated wetland in south central Nebraska was analyzed to assess consumptive water use and the potential for "water savings" as a result of vegetation eradication via herbicide treatment. Energy balance measurements were made at the field site for two growing seasons (treated and untreated), including observations of net radiation, heat storage, and sensible heat flux, which was measured using a large-aperture scintillometer. Latent heat flux was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons and with model simulations to examine the relative impacts of vegetation removal and climate variability. Observed ET rates dropped by roughly 32% between the two growing seasons, from a mean of 4.4 ± 0.7 mm day-1 in 2009 (with live vegetation) to 3.0 ± 0.8 mm day-1 in 2010 (with dead P. australis). These results are corroborated by the Agro-IBIS model simulations, and the reduction in ET implies a total "water savings" of 245 mm over the course of the growing season. The significant decreases in ET were accompanied by a more-than-doubling of sensible heat flux, as well as a ∼60% increase in heat storage due to decreased LAI. Removal of P. australis was also found to cause measurable changes in the local micrometeorology at the wetland. Consistent with the observed increase in sensible heat flux during 2010, warmer, drier, windier conditions were observed in the dead, P. australis section of the wetland, compared to an undisturbed section of live, native vegetation. Modeling results suggest that the elimination of transpiration in 2010 was partially offset by an increase in surface evaporation, thereby reducing the subsequent water savings by roughly 60%. Thus, the impact of vegetation removal depends on the local climate, depth to groundwater, and management decisions related to regrowth of vegetation.

  4. Variation in energy balance components from six sites in a native prairie for three years

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Qian, Ping

    1992-01-01

    Six automatic stations were used to evaluate the surface energy and radiation balances on a native prairie near Manhattan, Kansas, using the Bowen ratio technique for a total of 300 days. Data were taken during the periods from May 26 to October 16, 1987, May 10 to September 18, 1988, and July 21 to August 13, 1989. The station site locations were selected to represent burned and unburned treatments on ridges, valley bottoms, and slopes with various aspects. The measured variables were (1) air and wet bulb temperatures at two heights, (2) net radiation, (3) solar radiation (up and down), (4) total hemispherical radiation (up and down), (5) diffuse radiation, (6) soil heat flow and soil temperature, (7) wind speed, (8) wind direction, and (9) precipitation. Energy balance components at the sites were compared for the 3 years. The variation between sites and years was small, even though some sites were as much as 10 km apart and the years had different rainfall amounts. The average values for the four summer intensive field campaigns (IFCs) were as follows: albedo, 0.2; ratio of net radiation to solar radiation, 62 percent; evaporation equivalent, 4 mm/d; Bowen ratio, 0.32; evaporation fraction, 70 percent; and the ratio of evaporation to solar energy, 40 percent. These values were different for the fall IFC. The latent and sensible heat fluxes were more variable than the radiation terms reflecting soil moisture differences between IFCs.

  5. Botswana water and surface energy balance research program. Part 1: Integrated approach and field campaign results

    NASA Technical Reports Server (NTRS)

    Vandegriend, A. A.; Owe, M.; Vugts, H. F.; Ramothwa, G. K.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. Results of the first part of the program (Botswana 1) which ran from 1 Jan. 1988 - 31 Dec. 1990 are summarized. Botswana 1 consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components in general are described and activities performed during the surface energy modeling component including the extensive field campaign are summarized. The results of the passive microwave component are summarized. The key of the field campaign was a multilevel approach, whereby measurements by various similar sensors were made at several altitudes and resolution. Data collection was performed at two adjacent sites of contrasting surface character. The following measurements were made: micrometeorological measurements, surface temperatures, soil temperatures, soil moisture, vegetation (leaf area index and biomass), satellite data, aircraft data, atmospheric soundings, stomatal resistance, and surface emissivity.

  6. Snow evolution in Sierra Nevada, Spain) from an energy balance model validated with Landsat TM data

    NASA Astrophysics Data System (ADS)

    Herrero, Javier; Polo, María J.; Losada, Miguel A.

    2011-11-01

    Sierra Nevada Mountains are the highest continental altitude in Spain. Located in the South, facing the Mediterranean Sea in a distance of less than 40 km, the high level of solar energy income throughout the year, together with the extremely variable character of climate in such latitudes, make it necessary to use energy balance approaches to characterize the snow cover evolution. Wind and relative humidity become decisive factors in the evolution of the snow cover due to the high evaporation rates that can arise under favourable meteorological conditions. This work presents the enhanced capability of the combination of Landsat TM data with the simulation of an energy balance model to produce sequences of hourly high resolution maps of snow cover and depth distribution under variable meteorological conditions such as those found in Mediterranean mountainous watersheds. Despite the good agreement found between observed and predicted snow pixels, different examples of disagreement arose in the boundaries, most of them related to the temperature and wind speed spatial pattern simulation together with the discrimination between rain and snowfall occurrence.

  7. Battery cycle life balancing in a microgrid through flexible distribution of energy and storage resources

    NASA Astrophysics Data System (ADS)

    Khasawneh, Hussam J.; Illindala, Mahesh S.

    2014-09-01

    In this paper, a microgrid consisting of four fuel cell-battery hybrid Distributed Energy Resources (DERs) is devised for an industrial crusher-conveyor load. Each fuel cell was accompanied by a Li-ion battery to provide energy storage support under islanded condition of the microgrid since the fuel cells typically have poor transient response characteristics. After carrying out extensive modeling and analysis in MATLAB®, the battery utilization was found to vary significantly based on the DER's 'electrical' placement within the microgrid. This paper presents, under such conditions, a variety of battery life balancing solutions through the use of the new framework of Flexible Distribution of EneRgy and Storage Resources (FDERS). It is based on an in-situ reconfiguration approach through 'virtual' reactances that help in changing the 'electrical' position of each DER without physically displacing any component in the system. Several possible approaches toward balancing the battery utilization are compared in this paper taking advantage of the flexibility that FDERS offers. It was observed that the estimated battery life is dependent on factors such as cycling sequence, pattern, and occurrence.

  8. Perinatal exposure to high-fat diet programs energy balance, metabolism and behavior in adulthood.

    PubMed

    Sullivan, Elinor L; Smith, M Susan; Grove, Kevin L

    2011-01-01

    The perinatal environment plays an important role in programming many aspects of physiology and behavior including metabolism, body weight set point, energy balance regulation and predisposition to mental health-related disorders such as anxiety, depression and attention deficit hyperactivity disorder. Maternal health and nutritional status heavily influence the early environment and have a long-term impact on critical central pathways, including the melanocortinergic, serotonergic system and dopaminergic systems. Evidence from a variety of animal models including rodents and nonhuman primates indicates that exposure to maternal high-fat diet (HFD) consumption programs offspring for increased risk of adult obesity. Hyperphagia and increased preference for fatty and sugary foods are implicated as mechanisms for the increased obesity risk. The effects of maternal HFD consumption on energy expenditure are unclear, and future studies need to address the impact of perinatal HFD exposure on this important component of energy balance regulation. Recent evidence from animal models also indicates that maternal HFD consumption increases the risk of offspring developing mental health-related disorders such as anxiety. Potential mechanisms for perinatal HFD programming of neural pathways include circulating factors, such as hormones (leptin, insulin), nutrients (fatty acids, triglycerides and glucose) and inflammatory cytokines. As maternal HFD consumption and obesity are common and rapidly increasing, we speculate that future generations will be at increased risk for both metabolic and mental health disorders. Thus, it is critical that future studies identify therapeutic strategies that are effective at preventing maternal HFD-induced malprogramming. PMID:21079387

  9. Berardinelli-Seip congenital lipodystrophy 2 regulates adipocyte lipolysis, browning, and energy balance in adult animals.

    PubMed

    Zhou, Hongyi; Lei, Xinnuo; Benson, Tyler; Mintz, James; Xu, Xiaojing; Harris, Ruth B; Weintraub, Neal L; Wang, Xiaoling; Chen, Weiqin

    2015-10-01

    Mutations in BSCL2/SEIPIN cause Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2), but the mechanisms whereby Bscl2 regulates adipose tissue function are unclear. Here, we generated adipose tissue (mature) Bscl2 knockout (Ad-mKO) mice, in which Bscl2 was specifically ablated in adipocytes of adult animals, to investigate the impact of acquired Bscl2 deletion on adipose tissue function and energy balance. Ad-mKO mice displayed reduced adiposity and were protected against high fat diet-induced obesity, but not insulin resistance or hepatic steatosis. Gene expression profiling and biochemical assays revealed increased lipolysis and fatty acid oxidation in white adipose tissue (WAT) and brown adipose tissue , as well as browning of WAT, owing to induction of cAMP/protein kinase A signaling upon Bscl2 deletion. Interestingly, Bscl2 deletion reduced food intake and downregulated adipose β3-adrenergic receptor (ADRB3) expression. Impaired ADRB3 signaling partially offsets upregulated browning-induced energy expenditure and thermogenesis in Ad-mKO mice housed at ambient temperature. However, this counter-regulatory response was abrogated under thermoneutral conditions, resulting in even greater body mass loss in Ad-mKO mice. These findings suggest that Bscl2 regulates adipocyte lipolysis and β-adrenergic signaling to produce complex effects on adipose tissues and whole-body energy balance. PMID:26269358

  10. GRACE time-variable gravity field recovery using an improved energy balance approach

    NASA Astrophysics Data System (ADS)

    Shang, Kun; Guo, Junyi; Shum, C. K.; Dai, Chunli; Luo, Jia

    2015-12-01

    A new approach based on energy conservation principle for satellite gravimetry mission has been developed and yields more accurate estimation of in situ geopotential difference observables using K-band ranging (KBR) measurements from the Gravity Recovery and Climate Experiment (GRACE) twin-satellite mission. This new approach preserves more gravity information sensed by KBR range-rate measurements and reduces orbit error as compared to previous energy balance methods. Results from analysis of 11 yr of GRACE data indicated that the resulting geopotential difference estimates agree well with predicted values from official Level 2 solutions: with much higher correlation at 0.9, as compared to 0.5-0.8 reported by previous published energy balance studies. We demonstrate that our approach produced a comparable time-variable gravity solution with the Level 2 solutions. The regional GRACE temporal gravity solutions over Greenland reveals that a substantially higher temporal resolution is achievable at 10-d sampling as compared to the official monthly solutions, but without the compromise of spatial resolution, nor the need to use regularization or post-processing.

  11. Effect of the lower boundary position of the Fourier equation on the soil energy balance

    NASA Astrophysics Data System (ADS)

    Shufen, Sun; Xia, Zhang

    2004-12-01

    In this study, the effect of the lower boundary position selection for the Fourier equation on heat transfer and energy balance in soil is evaluated. A detailed numerical study shows that the proper position of the lower boundary is critical when solving the Fourier equation by using zero heat flux as the lower boundary condition. Since the position defines the capacity of soil as a heat sink or source, which absorbs and stores radiation energy from the sky in summer and then releases the energy to the atmosphere in winter, and regulates the deep soil temperature distribution, the depth of the position greatly influences the heat balance within the soil as well as the interaction between the soil and the atmosphere. Based on physical reasoning and the results of numerical simulation, the proper depth of the position should be equal to approximately 3 times of the annual heat wave damping depth. For most soils, the proper lower boundary depth for the Fourier equation should be around 8 m to 15 m, depending on soil texture.

  12. Baroreflex-mediated heart rate and vascular resistance responses 24 h after maximal exercise

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.

    2003-01-01

    INTRODUCTION: Plasma volume, heart rate (HR) variability, and stimulus-response relationships for baroreflex control of forearm vascular resistance (FVR) and HR were studied in eight healthy men after and without performing a bout of maximal exercise to test the hypotheses that acute expansion of plasma volume is associated with 1) reduction in baroreflex-mediated HR response, and 2) altered operational range for central venous pressure (CVP). METHODS: The relationship between stimulus (DeltaCVP) and vasoconstrictive reflex response (DeltaFVR) during unloading of cardiopulmonary baroreceptors was assessed with lower-body negative pressure (LBNP, 0, -5, -10, -15, -20 mm Hg). The relationship between stimulus (Deltamean arterial pressure (MAP)) and cardiac reflex response (DeltaHR) during loading of arterial baroreceptors was assessed with steady-state infusion of phenylephrine (PE) designed to increase MAP by 15 mm Hg alone and during application of LBNP (PE+LBNP) and neck pressure (PE+LBNP+NP). Measurements of vascular volume and autonomic baroreflex responses were conducted on two different test days, each separated by at least 1 wk. On one day, baroreflex response was tested 24 h after graded cycle exercise to volitional exhaustion. On another day, measurement of baroreflex response was repeated with no exercise (control). The order of exercise and control treatments was counterbalanced. RESULTS: Baseline CVP was elevated (P = 0.04) from a control value of 10.5 +/- 0.4 to 12.3 +/- 0.4 mm Hg 24 h after exercise. Average DeltaFVR/DeltaCVP during LBNP was not different (P = 0.942) between the exercise (-1.35 +/- 0.32 pru x mm Hg-1) and control (-1.32 +/- 0.36 pru x mm Hg-1) conditions. However, maximal exercise caused a shift along the reflex response relationship to a higher CVP and lower FVR. HR baroreflex response (DeltaHR/DeltaMAP) to PE+LBNP+NP was lower (P = 0.015) after maximal exercise (-0.43 +/- 0.15 beats x min-1 x mm Hg-1) compared with the control

  13. The friction coefficient of shoulder joints remains remarkably low over 24 h of loading.

    PubMed

    Jones, Brian K; Durney, Krista M; Hung, Clark T; Ateshian, Gerard A

    2015-11-01

    The frictional response of whole human joints over durations spanning activities of daily living has not been reported previously. This study measured the friction of human glenohumeral joints during 24 h of reciprocal loading in a pendulum testing device, at moderate (0.2 mm/s, 4320 cycles) and low (0.02 mm/s, 432 cycles) sliding speeds, under a 200 N load. The effect of joint congruence was also investigated by testing human humeral heads against significantly larger mature bovine glenoids. Eight human joints and six bovine joints were tested in four combinations: human joints tested at moderate (hHCMS, n=6) and low speed (hHCLS, n=3), human humeral heads tested against bovine glenoids at moderate speed (LCMS, n=3), and bovine joints tested at moderate speed (bHCMS, n=3). In the first half hour the mean±standard deviation of the friction coefficient was hHCMS: 0.0016±0.0011, hHCLS: 0.0012±0.0002, LCMS: 0.0008±0.0002 and bHCMS: 0.0024±0.0008; in the last four hours it was hHCMS: 0.0057±0.0025, hHCLS: 0.0047±0.0017, LCMS: 0.0012±0.0003 and bHCMS: 0.0056±0.0016. The initial value was lower than the final value (p<0.0001). The value in LCMS was significantly lower than in hHCMS and bHCMS (p<0.01). No visual damage was observed in any of the specimens. These are the first results to demonstrate that the friction coefficient of natural human shoulders remains remarkably low (averaging as little as 0.0015 and no greater than 0.006) for up to 24 h of continuous loading. The sustained low friction coefficients observed in incongruent joints (~0.001) likely represent rolling rather than sliding friction. PMID:26472306

  14. Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding.

    PubMed

    Kim, Tae Kwon; Tirloni, Lucas; Pinto, Antônio F M; Moresco, James; Yates, John R; da Silva Vaz, Itabajara; Mulenga, Albert

    2016-01-01

    Ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (TBD) agents in the USA. This study describes LC-MS/MS identification of 582 tick- and 83 rabbit proteins in saliva of I. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (BD), and spontaneously detached (SD). The 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity/antimicrobial (2.6%), lipocalin (3.1%), heme/iron binding (2.6%), extracellular matrix/ cell adhesion (2.2%), oxidant metabolism/ detoxification (6%), transporter/ receptor related (3.2%), cytoskeletal (5.5%), and housekeeping-like (39.7%). Notable observations include: (i) tick saliva proteins of unknown function accounting for >33% of total protein content, (ii) 79% of proteases are metalloproteases, (iii) 13% (76/582) of proteins in this study were found in saliva of other tick species and, (iv) ticks apparently selectively inject functionally similar but unique proteins every 24 h, which we speculate is the tick's antigenic variation equivalent strategy to protect important tick feeding functions from host immune system. The host immune responses to proteins present in 24 h I. scapularis saliva will not be effective at later feeding stages. Rabbit proteins identified in our study suggest the tick's strategic use of host proteins to modulate the feeding site. Notably fibrinogen, which is central to blood clotting and wound healing, was detected in high abundance in BD and SD saliva, when the tick is preparing to terminate feeding and detach from the host. A remarkable tick adaptation is that the feeding lesion is completely healed when the tick detaches from the host. Does the tick concentrate fibrinogen at the feeding site to aide in promoting healing of the feeding lesion? Overall, these data provide broad insight into molecular mechanisms regulating different tick

  15. Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding

    PubMed Central

    Pinto, Antônio F. M.; Moresco, James; Yates, John R.; da Silva Vaz, Itabajara; Mulenga, Albert

    2016-01-01

    Ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (TBD) agents in the USA. This study describes LC-MS/MS identification of 582 tick- and 83 rabbit proteins in saliva of I. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (BD), and spontaneously detached (SD). The 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity/antimicrobial (2.6%), lipocalin (3.1%), heme/iron binding (2.6%), extracellular matrix/ cell adhesion (2.2%), oxidant metabolism/ detoxification (6%), transporter/ receptor related (3.2%), cytoskeletal (5.5%), and housekeeping-like (39.7%). Notable observations include: (i) tick saliva proteins of unknown function accounting for >33% of total protein content, (ii) 79% of proteases are metalloproteases, (iii) 13% (76/582) of proteins in this study were found in saliva of other tick species and, (iv) ticks apparently selectively inject functionally similar but unique proteins every 24 h, which we speculate is the tick's antigenic variation equivalent strategy to protect important tick feeding functions from host immune system. The host immune responses to proteins present in 24 h I. scapularis saliva will not be effective at later feeding stages. Rabbit proteins identified in our study suggest the tick's strategic use of host proteins to modulate the feeding site. Notably fibrinogen, which is central to blood clotting and wound healing, was detected in high abundance in BD and SD saliva, when the tick is preparing to terminate feeding and detach from the host. A remarkable tick adaptation is that the feeding lesion is completely healed when the tick detaches from the host. Does the tick concentrate fibrinogen at the feeding site to aide in promoting healing of the feeding lesion? Overall, these data provide broad insight into molecular mechanisms regulating different tick

  16. Evapotranspiration and surface energy balance across an agricultural-urban landscape gradient in Southern California, USA.

    NASA Astrophysics Data System (ADS)

    Shiflett, S. A.; Anderson, R. G.; Jenerette, D.

    2014-12-01

    Urbanization substantially affects energy, surface and air temperature, and hydrology due to extensive modifications in land surface properties such as vegetation, albedo, thermal capacity and soil moisture. The magnitude and direction of these alterations depends heavily on the type of urbanization that occurs. We investigated energy balance variation in a local network of agricultural and urban ecosystems using the eddy covariance method to better understand how vegetation fraction and degree of urbanization affects energy exchanges between the land surface and the atmosphere. We deployed eddy flux systems within a well-irrigated, agricultural citrus orchard, a moderately developed urban zone with a substantial amount of local vegetative cover, and an intensely developed urban zone with minimal vegetative cover and increased impervious surfaces relative to the other two sites. Latent energy (LE) fluxes in the agricultural area ranged from 7.9 ± 1.4 W m-2 (nighttime) to 168.7 ± 6.2 W m-2 (daytime) compared to 10.2 ± 3.5 W m-2 and 40.6 ± 4.1 W m-2, respectively, for the moderately developed urban area. Sensible energy (H) fluxes ranged from -9.1 ± 1.0 W m-2 (nighttime) to 119 ± 7.0 W m-2 (daytime) in the agricultural area compared to 9.6 ± 2.6 W m-2 and 134 ± 6.0 W m-2, respectively, for the moderately developed urban zone. Daytime LE is reduced with increasing urbanization; however, daily cycles of LE are less recognizable in urban areas compared to distinct daily cycles obtained above a mature citrus crop. In contrast, both daytime and nighttime H increases with increasing degree of urbanization. Reduction in vegetation and increases in impervious surfaces along an urbanization gradient leads to alterations in energy balance, which are associated with microclimate and water use changes.

  17. The energy balance of wind waves and the remote sensing problem

    NASA Technical Reports Server (NTRS)

    Hasselmann, K.

    1972-01-01

    Measurements of wave growth indicate an energy balance of the wave spectrum governed primarily by input from the atmosphere, nonlinear transfer to shorter and longer waves, and advection. The pronounced spectral peak and sharp low frequency cut-off characteristic of fetch-limited spectra are explained as a self-stabilizing feature of the nonlinear wave-wave interactions. The momentum transferred from the atmosphere to the wind waves accounts for a large part of the wind drag. These findings are relevant for remote microwave sensing of the sea surface by backscatter and passive radiometry methods.

  18. The obesity‐associated gene Negr1 regulates aspects of energy balance in rat hypothalamic areas

    PubMed Central

    Boender, Arjen J.; van Gestel, Margriet A.; Garner, Keith M.; Luijendijk, Mieneke C. M.; Adan, Roger A. H.

    2014-01-01

    Abstract Neural growth regulator 1 (Negr1) is among the first common variants that have been associated with the regulation of body mass index. Using AAV technology directed to manipulate Negr1 expression in vivo, we find that decreased expression of Negr1 in periventricular hypothalamic areas leads to increases in body weight, presumably via increased food intake. Moreover, we observed that both increased and decreased levels of Negr1 lead to reduced locomotor activity and body temperature. In sum, our results provide further support for a role of hypothalamic expressed Negr1 in the regulation of energy balance. PMID:25077509

  19. Neuroendocrine circuits governing energy balance and stress regulation: functional overlap and therapeutic implications

    PubMed Central

    Ulrich-Lai, Yvonne M.; Ryan, Karen K.

    2014-01-01

    Significant co-morbidities between obesity-related metabolic disease and stress-related psychological disorders suggest important functional interactions between energy balance and brain stress integration. Largely overlapping neural circuits control these systems, and this anatomical arrangement optimizes opportunities for mutual influence. Here we first review the current literature identifying effects of metabolic neuroendocrine signals on stress regulation, and vice versa. Next, the contributions of reward driven food intake to these metabolic and stress interactions are discussed. Lastly, we consider the inter-relationships among metabolism, stress and reward in light of their important implications in the development of therapies for metabolism- or stress-related disease. PMID:24630812

  20. Atmospheric correction of LANDSAT TM thermal band using surface energy balance

    NASA Technical Reports Server (NTRS)

    Vidal, Alain; Devaux-Ros, Claire; Moran, M. Susan

    1994-01-01

    Thermal infrared data of LANDSAT Thematic Mapper (TM) are hardly used, probably due to the difficulties met when trying to correct them for atmospheric effects. A method for correcting these data was designed, based on surface energy balance estimation of known wet and dry targets included in the TM image to be corrected. This method, only using the image itself and local meteorological data was tested and validated on various surfaces: agricultural, forest and rangeland. The root mean square error on corrected temperatures is on the order of 1C.

  1. On the Capabilities of Using AIRSAR Data in Surface Energy/Water Balance Studies

    NASA Technical Reports Server (NTRS)

    Moreno, Jose F.; Saatchi, Sasan S.

    1996-01-01

    In this paper an algorithm is described that allows derivation of three fundamental parameters from synthetic aperture radar (SAR) data: soil moisture, soil roughness, and canopy water content, accounting for the effects of vegetation cover by using optical (Landsat) data as auxiliary. The capabilities and limitations of the data and algorithms are discussed, as well as possibilities to use these data in energy/water balance modeling studies. All of the data used in this study was acquired as part of the European Field Experiment in a Desertification Threatened Area.

  2. The Martian climate: Energy balance models with CO2/H2O atmospheres

    NASA Technical Reports Server (NTRS)

    Hoffert, M. I.

    1984-01-01

    Progress in the development of a multi-reservoir, time dependent energy balance climate model for Mars driven by prescribed insolation at the top of the atmosphere is reported. The first approximately half-year of the program was devoted to assembling and testing components of the full model. Specific accomplishments were made on a longwave radiation code, coupling seasonal solar input to a ground temperature simulation, and conceptualizing an approach to modeling the seasonal pressure waves that develop in the Martian atmosphere as a result of sublimation and condensation of CO2 in polar regions.

  3. The Role of The Electron Energy Balance in Plasma Thruster Instabilities

    SciTech Connect

    Peradzynski, Z.; Makowski, K.; Barral, S.; Kurzyna, J.; Dudeck, M.

    2008-03-19

    Using the fluid equations of Hall thruster plasma we analyze the influence of the electron energy balance on the stability of ion sound modes. For frequencies lower than {omega}{sub c} = 10{sup 7} s{sup -1} the gains and losses in the source term are approximately equal, thus the temperature can be in principle determined in terms of other dependent variables. This permits to reduce the number of equations. It appears however, that the new system can have complex characteristics in some regions. This in turn implies instability of certain modes with frequencies lower than {omega}{sub c}.

  4. Thermodynamic energy balance equations for Space Shuttle Orbiter gas compartment during ascent and re-entry

    NASA Technical Reports Server (NTRS)

    Ting, P. C.

    1982-01-01

    Thermodynamic energy balance equations are derived and applied to midsection Orbiter-payload atmospheric thermal math models (TMMs) to predict Orbiter component, element, compartment, internal insolation and structure temperatures in support of NASA/JSC mission planning, postflight thermal analysis and payload thermal integration planning. The equations are extended and applied to the forward section, midsection, and aft section of the TMMs for five Orbiter mission phases: prelaunch on pad with purge, lift-off to ascent, re-entry to touchdown, post landing without purge, and post-landing with purge. Predicted results from the 390 node/DFI atmospheric TMM are in good agreement with STS-1 flight measurement data.

  5. Simplifications of Simulation on Energy Balances and Estimations of a Hybrid Renewable Energy System for Use in Cold Climate Regions

    NASA Astrophysics Data System (ADS)

    Akpan, Itoro Etim; Sasaki, Masafumi; Endoh, Noboru

    A simplified double grade meteorological data model for the simulation of the annual performance of a domestic-size renewable energy system is proposed. With the model, only two representative days (clearest and cloudiest) during each season of the year are necessary to estimate annual energy balances, carbon emissions and the running costs. The model was chosen in preference to other simplified models based on the error distributions from the results of the continuous simulations in a test period. Detailed numerical simulation studies show that the carbon emissions from the renewable energy system are about 16%of a comparable conventional system. The thermal energy produced by a solar collector during the winter season, however, is insufficient to meet all the loads so that frequent heat pump operations and the auxiliary boiler are necessary in cold climate regions.

  6. Distributed modeling of snow cover mass and energy balance in the Rheraya watershed (High Atlas, Morocco)

    NASA Astrophysics Data System (ADS)

    Marchane, Ahmed; Gascoin, Simon; Jarlan, Lionel; Hanich, Lahoucine

    2016-04-01

    The mountains of the High Moroccan Atlas represent an important source of water for the neighboring arid plains. Despite the importance of snow in the regional water balance, few studies were devoted to the modeling of the snow cover at the watershed scale. This type of modeling is necessary to characterize the contribution of snowmelt to water balance and understanding its sensitivity to natural and human-induced climate fluctuations. In this study, we applied a spatially-distributed model of the snowpack evolution (SnowModel, Liston & Elder 2006) on the Rheraya watershed (225 km²) in the High Atlas in order to simulate the mass and energy balance of the snow cover and the evolution of snow depth over a full season (2008-2009). The model was forced by 6 meteorological stations. The model was evaluated locally at the Oukaimeden meteorological station (3230 m asl) where snow depth is recorded continuously. To evaluate the model at the watershed scale we used the daily MODIS snow cover products and a series of 15 cloud-free optical images acquired by the FORMOSAT-2 satellite at 8-m resolution from February to June 2009. The results showed that the model is able to simulate the snow depth in the Oukaimeden station for the 2008-2009 season, and also to simulate the spatial and temporal variation of of the snow cover area in the watershed Rheraya. Based on the model output we examine the importance of the snow sublimation on the water balance at the watershed scale.

  7. Multihadron production dynamics exploring the energy balance in hadronic and nuclear collisions

    NASA Astrophysics Data System (ADS)

    Sarkisyan, Edward K. G.; Mishra, Aditya Nath; Sahoo, Raghunath; Sakharov, Alexander S.

    2016-03-01

    The relation of multihadron production in nucleus-nucleus and (anti)proton-proton collisions is studied by exploring the collision-energy and centrality dependencies of the charged particle mean multiplicity in the measurements to date. The study is performed in the framework of the recently proposed effective-energy approach which, under the proper scaling of the collision energy, combines the constituent quark picture with Landau relativistic hydrodynamics counting for the centrality-defined effective energy of participants. Within this approach, the multiplicity energy dependence and the pseudorapidity spectra from the most central nuclear collisions are well reproduced. The study of the multiplicity centrality dependence reveals a new scaling between the measured pseudorapidity spectra and the calculations. By means of this scaling, referred to as energy-balanced limiting fragmentation scaling, one reproduces the pseudorapidity spectra for all centralities. The scaling elucidates some differences in the multiplicity and midrapidity density centrality dependence obtained at RHIC and LHC. These findings reveal an inherent similarity in the multiplicity energy dependence from the most central collisions and centrality data. Predictions are made for the mean multiplicities to be measured in proton-proton and heavy-ion collisions at the LHC.

  8. Open dissipative seismic systems and ensembles of strong earthquakes: energy balance and entropy funnels

    NASA Astrophysics Data System (ADS)

    Akopian, Samvel Ts.

    2015-06-01

    A concept of seismic system (SS), which is responsible for the preparation of an ensemble of strong earthquakes, is considered as an open dissipative system exchanging energy and entropy with the environment. Open dissipative SS allow one to describe the equilibrium and non-equilibrium states of SS, and the lithosphere evolution under different plate tectonic settings on the basis of seismostatistics. Several new seismic parameters (`seismic temperature', `seismic time', dissipation function, efficiency, inelastic energy, dynamical probability) are defined and proposed for better understanding and describing the dynamical processes. The Sakhalin SS is considered to illustrate the behaviour of proposed parameters. By analogy to Liouville's equation in thermodynamics, it is shown that there is no criterion of instability in the domain where the Gutenberg-Richter law is true. In the proposed approach, the instability origination and the formation of seismogenic structures in the lithosphere are based on the energy versus information entropy power law; the existence of `time arrow' also proceeds from such a dependence. Application of energy and trajectory diagrams enables to describe the preparation of strong earthquakes within an ensemble in terms of slow and fast timescales. These diagrams help perform the spatiotemporal-energy monitoring of the instability origination in the lithosphere. It is shown that the information entropy parameter can serve as a measure of the unknown external energy flow into the system (this energy is supplied for the elastic radiation energy in the earthquake sources and for inelastic processes in the system volume). The property of the ensemble of strong earthquakes is periodically to restore the SS equilibrium state that enables to describe the SS energy balance. The results offer possibilities to estimate the fraction of inelastic energy released by the SS medium during the preparation and occurrence of seismic catastrophes. The

  9. Cerebral blood flow velocity in humans exposed to 24 h of head-down tilt

    NASA Technical Reports Server (NTRS)

    Kawai, Y.; Murthy, G.; Watenpaugh, D. E.; Breit, G. A.; Deroshia, C. W.; Hargens, A. R.

    1993-01-01

    This study investigates cerebral blood flow (CBF) velocity in humans before, during, and after 24 h of 6 deg head-down tilt (HDT), which is a currently accepted experimental model to simulate microgravity. CBF velocity was measured by use of the transcranial Doppler technique in the right middle cerebral artery of eight healthy male subjects. Mean CBF velocity increased from the pre-HDT upright seated baseline value of 55.5 +/- 3.7 (SE) cm/s to 61.5 +/- 3.3 cm/s at 0.5 h of HDT, reached a peak value of 63.2 +/- 4.1 cm/s at 3 h of HDT, and remained significantly above the pre-HDT baseline for over 6 h of HDT. During upright seated recovery, mean CBF velocity decreased to 87 percent of the pre-HDT baseline value. Mean CBF velocity correlated well with calculated intracranial arterial pressure (IAP). As analyzed by linear regression, mean CBF velocity = 29.6 + 0.32IAP. These results suggest that HDT increases CBF velocity by increasing IAP during several hours after the onset of microgravity. Importantly, the decrease in CBF velocity after HDT may be responsible, in part, for the increased risk of syncope observed in subjects after prolonged bed rest and also in astronauts returning to Earth.

  10. Gender differences in the impact of daily sadness on 24-h heart rate variability.

    PubMed

    Verkuil, Bart; Brosschot, Jos F; Marques, Andrea H; Kampschroer, Kevin; Sternberg, Esther M; Thayer, Julian F

    2015-12-01

    Reduced heart rate variability (HRV) is proposed to mediate the relation between depressive symptoms and cardiovascular health problems. Yet, several studies have found that in women depression is associated with higher HRV levels, whereas in men depression is associated with lower HRV levels. So far, these studies have only examined gender differences in HRV levels using a single assessment. This study aimed to test the interactive effects of gender and sadness on ambulatory-assessed HRV levels. A sample of 60 (41 women) employees participated in an ambulatory study. HRV levels (mean of successive differences; MSD) were continuously measured for 24 h. During the daytime, hourly assessments of sadness and other mood states were taken, while depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale (CES-D). Gender differences were observed when examining the impact of average daily sadness on MSD. In women, but not in men, the total amount of sadness experienced during the day was associated with higher circadian MSD levels. These findings suggest that researchers need to take gender differences into account when examining the relation between sadness, HRV, and cardiovascular problems. PMID:26338472

  11. Subcellular energy balance of Odontesthes bonariensis exposed to a glyphosate-based herbicide.

    PubMed

    Menéndez-Helman, Renata J; Miranda, Leandro A; Dos Santos Afonso, Maria; Salibián, Alfredo

    2015-04-01

    Water pollution by agrochemicals is currently one of the most critical problems for the conservation of aquatic ecosystems. Glyphosate [N-(phosphonomethyl) glycine); PMG] is the main broad-spectrum post emergence herbicide used for the control of a wide range of pests in soybean crops. Adenylate energy charge (AEC) reflects the energy balance of the cells, a measure of the energy available from the adenylate pool: adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP). Background adenylates, phosphagens and the AEC index of two year old Odontesthes bonariensis were determined in some tissues by HPLC, and the impact on subcellular energy balance of sublethal glyphosate-based herbicide exposure was analyzed. The doses used were 0 (control tank), 1 or 10mg PMGL(-1), trials were carried out during 15 days. AEC values in brain, liver and muscle from control fish were 0.37 ± 0.02, 0.49 ± 0.05 and 0.56 ± 0.03, respectively (means ± SEM). While brain ATP concentrations were undetectable (hence low values of AEC), the muscle tissue showed the highest concentrations of the more energetic molecules: 0.18 μmole ATP g(-1) and 8 μmole phosphocreatine g(-1) (PCrg(-1)). In the brain, no significant changes were detected in exposed fish compared to controls. Instead, in both the liver and muscle of animals exposed to the highest concentration of the herbicide, significant changes in the AEC (reduction of 26% and 15%, p<0.05) with respect to the control group were determined. Chronic exposure (15 days) of Odontesthes bonariensis to 1 and 10mgL(-1) of formulated glyphosate did not affect brain AEC. However, the highest concentration of the herbicide produced a significant decrease in liver and muscle AEC manifesting adverse sublethal effects on the energy metabolism. These results suggest the usefulness of AEC as a biomarker of fish glyphosate exposure. PMID:25637751

  12. Reconciling Observations of Global Sea Level Rise with Changes in the Earth's Energy Balance

    NASA Astrophysics Data System (ADS)

    Willis, J.; Wong, T.; Hobbs, W. R.

    2011-12-01

    Ocean warming and the thermal expansion of seawater account for a sizable portion of global sea-level rise during the past two decades. The rate of ocean warming, however, carries additional climatic significance because the vast majority of any excess heat trapped in the Earth's climate system winds up warming the oceans. Thus in addition to the implications for sea level rise, ocean warming rates also provide a measure of the net radiative balance of the Earth as a whole. Despite its importance, the historical record of global ocean warming still contains large uncertainties. Prior to global deployment of the Argo array in about 2005, the historical record of ocean warming is dominated by data from eXpendable BathyThermographs (XBTs), which are known to contain sizable systematic errors. Global ocean warming during the transition period between XBT and Argo data therefore remains highly uncertain. In this study, we consider observations from the Clouds and the Earth's Radiant Energy System (CERES) instruments to assess the Earth's net radiation balance from 2000 to 2010. These observations provide an important constraint on ocean warming rates during the critical period from 2003 to 2005 when ocean temperature observations transitioned from XBT to Argo data. Observations of the net change in ocean mass from GRACE, as well as the net change in total sea level rise from altimetry will also be used to constrain ocean warming rates during this period. Given these constraints, we will assess the validity of different corrections for XBT biases and will assess both the global sea level budget and energy balance during the first decade of the 2000s.

  13. What balance do countries exhibit between the central human resources: water, energy and food

    NASA Astrophysics Data System (ADS)

    Kossak, Julian; Reusser, Dominik E.; Kropp, Jürgen P.

    2013-04-01

    Sufficient water, food and energy is a precondition for human activities. The water, energy and food nexus states that to some extend, these resources can replace each another: land can be used to produce food or energy crops; water can be used as direct water supply, to produce energy or for irrigation; and energy supports water treatment and agricultural yield. We present an overview of the major components of the trade-off together with a set of indicators and data sources to assess these components. The different indicators of the trade-off are summarized and plotted in a novel way on a triangle, which we discuss in view of the resource availability of different countries. Comparing different countries in view of their balance between water, food and energy will inform the discussion about the transition towards more sustainable societies and highlighting alternative strategies for development. This is important in view of possible synergies between the different sectors and as a tool for better coordinated governance approaches.

  14. Regulation of Energy Balance via BDNF Expressed in Nonparaventricular Hypothalamic Neurons.

    PubMed

    Yang, Haili; An, Juan Ji; Sun, Chao; Xu, Baoji

    2016-05-01

    Brain-derived neurotrophic factor (BDNF) expressed in the paraventricular hypothalamus (PVH) has been shown to play a key role in regulating energy intake and energy expenditure. BDNF is also expressed in other hypothalamic nuclei; however, the role in the control of energy balance for BDNF produced in these structures remains largely unknown. We found that deleting the Bdnf gene in the ventromedial hypothalamus (VMH) during embryogenesis using the Sf1-Cre transgene had no effect on body weight in mice. In contrast, deleting the Bdnf gene in the adult VMH using Cre-expressing virus led to significant hyperphagia and obesity. These observations indicate that the lack of a hyperphagia phenotype in the Sf1-Cre/Bdnf mutant mice is likely due to developmental compensation. To investigate the role of BDNF expressed in other hypothalamic areas, we employed the hypothalamus-specific Nkx2.1-Cre transgene to delete the Bdnf gene. We found that the Nkx2.1-Cre transgene could abolish BDNF expression in many hypothalamic nuclei, but not in the PVH, and that the resulting mutant mice developed modest obesity due to reduced energy expenditure. Thus, BDNF produced in the VMH plays a role in regulating energy intake. Furthermore, BDNF expressed in hypothalamic areas other than PVH and VMH is also involved in the control of energy expenditure. PMID:27003443

  15. Universality of particle production and energy balance in hadronic and nuclear collisions

    NASA Astrophysics Data System (ADS)

    Nath Mishra, Aditya; Sarkisyan, Edward K. G.; Sahoo, Raghunath; Sakharov, Alexander S.

    2016-07-01

    The multihadron production in nucleus-nucleus and (anti)proton-proton collisions is studied by exploring the collision-energy and centrality dependencies of the mean multiplicity in the existing data. The study is performed in the framework of the recently proposed effective-energy approach which combines the constituent quark picture and Landau hydrodynamics counting for the centrality-defined effective energy of participants. Within this approach, the multiplicity energy dependence and the pseudorapidity spectra from the most central nuclear collisions are well reproduced. The study of the multiplicity centrality dependence reveals a new scaling between the measured pseudorapidity spectra and the calculations. Using this scaling, called the energy balanced limiting fragmentation scaling, the pseudorapidity spectra are well reproduced for all centralities. The scaling clarifies some differences in the multiplicity and midrapidity density centrality dependence from RHIC and LHC. A similarity in the multiplicity energy dependence in the most central collisions and centrality data is shown. Predictions are drawn for the mean multiplicities to be measured in hadronic and heavy-ion collisions at the LHC.

  16. Contributions of divergent and nondivergent winds to the kinetic energy balance of a severe storm environment

    NASA Technical Reports Server (NTRS)

    Browning, P. A.; Fuelberg, H. E.

    1983-01-01

    Divergent and rotational components of the synoptic scale kinetic energy balance are presented using rawinsonde data at 3 and 6 h intervals from the Atmospheric Variability Experiment (AVE 4). Two intense thunderstorm complexes occurred during the period. Energy budgets are described for the entire computational region and for limited volumes that enclose and move with the convection. Although small in magnitude, the divergent wind component played an important role in the cross contour generation and horizontal flux divergence of kinetic energy. The importance of V sub D appears directly to the presence and intensity of convection within the area. Although K sub D usually comprised less than 10 percent of the total kinetic energy content within the storm environment, as much as 87 percent of the total horizontal flux divergence and 68 percent of the total cross contour generation was due to the divergent component in the upper atmosphere. Generation of kinetic energy by the divergent component appears to be a major factor in the creation of an upper level wind maximum on the poleward side of one of the complexes. A random error analysis is presented to assess confidence limits in the various energy parameters.

  17. Phenotypic vulnerability of energy balance responses to sleep loss in healthy adults

    PubMed Central

    Spaeth, Andrea M.; Dinges, David F.; Goel, Namni

    2015-01-01

    Short sleep duration is a risk factor for increased hunger and caloric intake, late-night eating, attenuated fat loss when dieting, and for weight gain and obesity. It is unknown whether altered energy-balance responses to sleep loss are stable (phenotypic) over time, and the extent to which individuals differ in vulnerability to such responses. Healthy adults experienced two laboratory exposures to sleep restriction separated by 60–2132 days. Caloric intake, meal timing and weight were objectively measured. Although there were substantial phenotypic differences among participants in weight gain, increased caloric intake, and late-night eating and fat intake, responses within participants showed stability across sleep restriction exposures. Weight change was consistent in both normal-weight and overweight adults. Weight change and increased caloric intake were more stable in men whereas late-night eating was consistent in both genders. This is the first evidence of phenotypic differential vulnerability and trait-like stability of energy balance responses to repeated sleep restriction, underscoring the need for biomarkers and countermeasures to predict and mitigate this vulnerability. PMID:26446681

  18. DEPTOR in POMC neurons affects liver metabolism but is dispensable for the regulation of energy balance

    PubMed Central

    Caron, Alexandre; Labbé, Sébastien M.; Mouchiroud, Mathilde; Huard, Renaud; Richard, Denis

    2016-01-01

    We have recently demonstrated that specific overexpression of DEP-domain containing mTOR-interacting protein (DEPTOR) in the mediobasal hypothalamus (MBH) protects mice against high-fat diet-induced obesity, revealing DEPTOR as a significant contributor to energy balance regulation. On the basis of evidence that DEPTOR is expressed in the proopiomelanocortin (POMC) neurons of the MBH, the present study aimed to investigate whether these neurons mediate the metabolic effects of DEPTOR. Here, we report that specific DEPTOR overexpression in POMC neurons does not recapitulate any of the phenotypes observed when the protein was overexpressed in the MBH. Unlike the previous model, mice overexpressing DEPTOR only in POMC neurons 1) did not show differences in feeding behavior, 2) did not exhibit changes in locomotion activity and oxygen consumption, 3) did not show an improvement in systemic glucose metabolism, and 4) were not resistant to high-fat diet-induced obesity. These results support the idea that other neuronal populations are responsible for these phenotypes. Nonetheless, we observed a mild elevation in fasting blood glucose, insulin resistance, and alterations in liver glucose and lipid homeostasis in mice overexpressing DEPTOR in POMC neurons. Taken together, these results show that DEPTOR overexpression in POMC neurons does not affect energy balance regulation but could modulate metabolism through a brain-liver connection. PMID:27097662

  19. Sensitivity Analysis on Remote Sensing Evapotranspiration Algorithm of Surface Energy Balance for Land

    NASA Astrophysics Data System (ADS)

    Wang, J.; Samms, T.; Meier, C.; Simmons, L.; Miller, D.; Bathke, D.

    2005-12-01

    Spatial evapotranspiration (ET) is usually estimated by Surface Energy Balance Algorithm for Land. The average accuracy of the algorithm is 85% on daily basis and 95% on seasonable basis. However, the accuracy of the algorithm varies from 67% to 95% on instantaneous ET estimates and, as reported in 18 studies, 70% to 98% on 1 to 10-day ET estimates. There is a need to understand the sensitivity of the ET calculation with respect to the algorithm variables and equations. With an increased understanding, information can be developed to improve the algorithm, and to better identify the key variables and equations. A Modified Surface Energy Balance Algorithm for Land (MSEBAL) was developed and validated with data from a pecan orchard and an alfalfa field. The MSEBAL uses ground reflectance and temperature data from ASTER sensors along with humidity, wind speed, and solar radiation data from a local weather station. MSEBAL outputs hourly and daily ET with 90 m by 90 m resolution. A sensitivity analysis was conducted for MSEBAL on ET calculation. In order to observe the sensitivity of the calculation to a particular variable, the value of that variable was changed while holding the magnitudes of the other variables. The key variables and equations to which the ET calculation most sensitive were determined in this study. href='http://weather.nmsu.edu/pecans/SEBALFolder/San%20Francisco%20AGU%20meeting/ASensitivityAnalysisonMSE">http://weather.nmsu.edu/pecans/SEBALFolder/San%20Francisco%20AGU%20meeting/ASensitivityAnalysisonMSE

  20. Urinary C-peptide tracks seasonal and individual variation in energy balance in wild chimpanzees.

    PubMed

    Emery Thompson, Melissa; Muller, Martin N; Wrangham, Richard W; Lwanga, Jeremiah S; Potts, Kevin B

    2009-02-01

    C-peptide of insulin presents a promising new tool for behavioral ecologists that allows for regular, non-invasive assessment of energetic condition in wild animals. C-peptide is produced on an equimolar basis with insulin, thus is indicative of the body's response to available glucose and, with repeated measurement, provides a biomarker of energy balance. As yet, few studies have validated the efficacy of C-peptide for monitoring energy balance in wild animals. Here, we assess seasonal and interindividual variation in urinary C-peptide concentrations of East African chimpanzees (Pan troglodytes schweinfurthii). We assayed 519 urine samples from 13 adult male chimpanzees in the Kanyawara community of Kibale National Park, Uganda. C-peptide levels were significantly predicted by the total amount of fruit and the amount of preferred fruit in the diet. However, chimpanzees had very low C-peptide titers during an epidemic of severe respiratory illness, despite highly favorable feeding conditions. Kanyawara males had significantly lower C-peptide levels than males at Ngogo, a nearby chimpanzee community occupying a more productive habitat. Among Kanyawara males, low-ranking males had consistently higher C-peptide levels than dominant males. While counterintuitive, this result supports previous findings of costs associated with dominance in male chimpanzees. Our preliminary investigations demonstrate that C-peptide has wide applications in field research, providing an accessible tool for evaluating seasonal and individual variation in energetic condition, as well as the costs of processes such as immune function and reproduction. PMID:19084530

  1. Experimental Investigation of the Energy-Balance of an Alpine Catchment

    NASA Astrophysics Data System (ADS)

    Gallice, A.; Huwald, H.; Mutzner, R.; Parlange, M. B.

    2013-12-01

    Water temperature is an important environmental factor which affects the habitat suitability of many fish species and is of central interest for many ecohydrological studies. Over the past 30 years, the scientific community has focused on the understanding and modeling of the mechanisms controlling in-stream temperature. However, the thermal regime of water in the unchanneled state has been poorly studied so far, so that the mechanisms linking precipitation temperature to the water temperature in the stream channel are still unresolved. In particular, existing stream temperature models either rely on direct measurements or on simple correlations with the air temperature to estimate the temperature of stream sources and tributaries. The present study is seen as a first step towards a more physically based computation of such temperatures. The energy balance of a medium-sized alpine catchment (20 km2) is investigated in detail using a set of meteorological and hydrological observations. Particular attention is given to the physical quantities, in particular ground temperature, which affect water temperature in the unchanneled state. The database used for this study was collected over the past six years and contains meteorological data from a high-density network of wireless weather stations, as well as river stage, discharge and temperature measurements. The present work lays the foundations for the future development of an energy balance model at the catchment scale, which will be able to compute the temperature of surface, interflow and baseflow runoffs - and therefore provide some boundary conditions to the actual stream temperature models.

  2. The role of willow-birch forest in the surface energy balance at arctic treeline

    SciTech Connect

    Blanken, P.D. ); Rouse, W.R. )

    1994-11-01

    Continuous measurements of the energy balance components were made during the 1991 growing season over a willow-birch forest located near Churchill, Manitoba, Canada. On the basis of measurements of leaf area index, the growing season was divided into three distinct periods: growth, mature, and senescence. Changes in surface albedo were strongly correlated with changing leaf area index during the growth period with albedo increasing as leaf area increased. The latent heat flux density, Q[sub E], represented 74% of net radiation during the mature period compared to 55 and 54% during the growth and senescence periods, respectively. The greater Q[sub E] at plant maturity is due primarily to canopy transpiration. The sensitivity of Q[sub E] to net radiation was largest during the growth period. In contrast, the sensitivity of Q[sub E] to the surface resistance and aerodynamic resistance was the largest during the mature period. The implications of climate variability on the timing of leaf development and the surface energy and water balance are discussed. 28 refs., 8 figs., 1 tab.

  3. Effects of acute intermittent hypoxia on energy balance and hypothalamic feeding pathways.

    PubMed

    Moreau, J M; Ciriello, J

    2013-12-01

    This study was done to investigate the effects of acute intermittent hypoxia (IH) on metabolic factors associated with energy balance and body weight, and on hypothalamic satiety-inducing pathways. Adult male Sprague-Dawley rats were exposed to either 8h IH or normoxic control conditions. Food intake, locomotion and body weights were examined after IH. Additionally, plasma levels of leptin, adiponectin corticosterone, insulin and blood glucose were measured following exposure to IH. Furthermore, adipose tissue was removed and analyzed for leptin and adiponectin content. Finally, the hypothalamic arcuate nucleus (ARC) was assessed for alterations in protein signaling associated with satiety. IH reduced body weight, food intake and active cycle locomotion without altering adipose tissue mass. Leptin protein content was reduced while adiponectin content was elevated in adipose tissue after IH. Plasma concentration of leptin was significantly increased while adiponectin decreased after IH. No changes were found in plasma corticosterone, insulin and blood glucose. In ARC, phosphorylation of signal transducer and activator of transcription-3 and pro-opiomelanocortin (POMC) expression were elevated. In addition, POMC-expressing neurons were activated as determined by immediate early gene FRA-1/2 expression. Finally, ERK1/2 and its phosphorylation were reduced in response to IH. These data suggest that IH induces significant alterations to body energy balance through changes in the secretion of leptin which exert effects on satiety-inducing pathways within the hypothalamus. PMID:24042039

  4. The greenhouse gas and energy balance of different treatment concepts for bio-waste.

    PubMed

    Ortner, Maria E; Müller, Wolfgang; Bockreis, Anke

    2013-10-01

    The greenhouse gas (GHG) and energy performance of bio-waste treatment plants been investigated for three characteristic bio-waste treatment concepts: composting; biological drying for the production of biomass fuel fractions; and anaerobic digestion. Compared with other studies about the environmental impacts of bio-waste management, this study focused on the direct comparison of the latest process concepts and state-of-the-art emission control measures. To enable a comparison, the mass balance and products were modelled for all process concepts assuming the same bio-waste amounts and properties. In addition, the value of compost as a soil improver was included in the evaluation, using straw as a reference system. This aspect has rarely been accounted for in other studies. The study is based on data from operational facilities combined with literature data. The results show that all three concepts contribute to a reduction of GHG emissions and show a positive balance for cumulated energy demand. However, in contrast to other studies, the advantage of anaerobic digestion compared with composting is smaller as a result of accounting for the soil improving properties of compost. Still, anaerobic digestion is the environmentally superior solution. The results are intended to inform decision makers about the relevant aspects of bio-waste treatment regarding the environmental impacts of different bio-waste management strategies. PMID:24008328

  5. Lysimetric evaluation of simplified surface energy balance approach in the Texas high plains

    USGS Publications Warehouse

    Gowda, P.H.; Senay, G.B.; Howell, T.A.; Marek, T.H.

    2009-01-01

    Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data to estimate evapotranspiration (ET) regionally. However, most EB models are complex to use and efforts are being made to simplify procedures mainly through the scaling of reference ET. The Simplified Surface Energy Balance (SSEB) is one such method. This approach has never been evaluated using measured ET data. In this study, the SSEB approach was applied to 14 Landsat TM images covering a major portion of the Southern High Plains that were acquired during 2006 and 2007 cropping seasons. Performance of the SSEB was evaluated by comparing estimated ET with measured daily ET from four large monolithic lysimeters at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas. Statistical evaluation of results indicated that the SSEB accounted for 84% of the variability in the measured ET values with a slope and intercept of 0.75 and 1.1 mm d-1, respectively. Considering the minimal amount of ancillary data required and excellent performance in predicting daily ET, the SSEB approach is a promising tool for mapping ET in the semiarid Texas High Plains and in other parts of the world with similar hydro-climatic conditions.

  6. Lysimetric Evaluation of Simplified Surface Energy Balance Approach in the Texas High Plains

    USGS Publications Warehouse

    Senay, Gabriel B.; Gowda, P.H.; Howell, T.A.; Marek, T.H.

    2009-01-01

    Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data to estimate evapotranspiration (ET) regionally. However, most EB models are complex to use and efforts are being made to simplify procedures mainly through the scaling of reference ET. The Simplified Surface Energy Balance (SSEB) is one such method. This approach has never been evaluated using measured ET data. In this study, the SSEB approach was applied to fourteen Landsat TM images covering a major portion of the Southern High Plains that were acquired during 2006 and 2007 cropping seasons. Performance of the SSEB was evaluated by comparing estimated ET with measured daily ET from four large monolithic lysimeters at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas. Statistical evaluation of results indicated that the SSEB accounted for 84% of the variability in the measured ET values with a slope and intercept of 0.75 and 1.1 mm d-1, respectively. Considering the minimal amount of ancillary data required and excellent performance in predicting daily ET, the SSEB approach is a promising tool for mapping ET in the semiarid Texas High Plains and in other parts of the world with similar hydro-climatic conditions.

  7. Improving iterative surface energy balance convergence for remote sensing based flux calculation

    NASA Astrophysics Data System (ADS)

    Dhungel, Ramesh; Allen, Richard G.; Trezza, Ricardo

    2016-04-01

    A modification of the iterative procedure of the surface energy balance was purposed to expedite the convergence of Monin-Obukhov stability correction utilized by the remote sensing based flux calculation. This was demonstrated using ground-based weather stations as well as the gridded weather data (North American Regional Reanalysis) and remote sensing based (Landsat 5, 7) images. The study was conducted for different land-use classes in southern Idaho and northern California for multiple satellite overpasses. The convergence behavior of a selected Landsat pixel as well as all of the Landsat pixels within the area of interest was analyzed. Modified version needed multiple times less iteration compared to the current iterative technique. At the time of low wind speed (˜1.3 m/s), the current iterative technique was not able to find a solution of surface energy balance for all of the Landsat pixels, while the modified version was able to achieve it in a few iterations. The study will facilitate many operational evapotranspiration models to avoid the nonconvergence in low wind speeds, which helps to increase the accuracy of flux calculations.

  8. DEPTOR in POMC neurons affects liver metabolism but is dispensable for the regulation of energy balance.

    PubMed

    Caron, Alexandre; Labbé, Sébastien M; Mouchiroud, Mathilde; Huard, Renaud; Richard, Denis; Laplante, Mathieu

    2016-06-01

    We have recently demonstrated that specific overexpression of DEP-domain containing mTOR-interacting protein (DEPTOR) in the mediobasal hypothalamus (MBH) protects mice against high-fat diet-induced obesity, revealing DEPTOR as a significant contributor to energy balance regulation. On the basis of evidence that DEPTOR is expressed in the proopiomelanocortin (POMC) neurons of the MBH, the present study aimed to investigate whether these neurons mediate the metabolic effects of DEPTOR. Here, we report that specific DEPTOR overexpression in POMC neurons does not recapitulate any of the phenotypes observed when the protein was overexpressed in the MBH. Unlike the previous model, mice overexpressing DEPTOR only in POMC neurons 1) did not show differences in feeding behavior, 2) did not exhibit changes in locomotion activity and oxygen consumption, 3) did not show an improvement in systemic glucose metabolism, and 4) were not resistant to high-fat diet-induced obesity. These results support the idea that other neuronal populations are responsible for these phenotypes. Nonetheless, we observed a mild elevation in fasting blood glucose, insulin resistance, and alterations in liver glucose and lipid homeostasis in mice overexpressing DEPTOR in POMC neurons. Taken together, these results show that DEPTOR overexpression in POMC neurons does not affect energy balance regulation but could modulate metabolism through a brain-liver connection. PMID:27097662

  9. A microscale three-dimensional urban energy balance model for studying surface temperatures

    NASA Astrophysics Data System (ADS)

    Krayenhoff, E. Scott; Voogt, James A.

    2007-06-01

    A microscale three-dimensional (3-D) urban energy balance model, Temperatures of Urban Facets in 3-D (TUF-3D), is developed to predict urban surface temperatures for a variety of surface geometries and properties, weather conditions, and solar angles. The surface is composed of plane-parallel facets: roofs, walls, and streets, which are further sub-divided into identical square patches, resulting in a 3-D raster-type model geometry. The model code is structured into radiation, conduction and convection sub-models. The radiation sub-model uses the radiosity approach and accounts for multiple reflections and shading of direct solar radiation. Conduction is solved by finite differencing of the heat conduction equation, and convection is modelled by empirically relating patch heat transfer coefficients to the momentum forcing and the building morphology. The radiation and conduction sub-models are tested individually against measurements, and the complete model is tested against full-scale urban surface temperature and energy balance observations. Modelled surface temperatures perform well at both the facet-average and the sub-facet scales given the precision of the observations and the uncertainties in the model inputs. The model has several potential applications, such as the calculation of radiative loads, and the investigation of effective thermal anisotropy (when combined with a sensor-view model).

  10. Phenotypic vulnerability of energy balance responses to sleep loss in healthy adults.

    PubMed

    Spaeth, Andrea M; Dinges, David F; Goel, Namni

    2015-01-01

    Short sleep duration is a risk factor for increased hunger and caloric intake, late-night eating, attenuated fat loss when dieting, and for weight gain and obesity. It is unknown whether altered energy-balance responses to sleep loss are stable (phenotypic) over time, and the extent to which individuals differ in vulnerability to such responses. Healthy adults experienced two laboratory exposures to sleep restriction separated by 60-2132 days. Caloric intake, meal timing and weight were objectively measured. Although there were substantial phenotypic differences among participants in weight gain, increased caloric intake, and late-night eating and fat intake, responses within participants showed stability across sleep restriction exposures. Weight change was consistent in both normal-weight and overweight adults. Weight change and increased caloric intake were more stable in men whereas late-night eating was consistent in both genders. This is the first evidence of phenotypic differential vulnerability and trait-like stability of energy balance responses to repeated sleep restriction, underscoring the need for biomarkers and countermeasures to predict and mitigate this vulnerability. PMID:26446681

  11. 24-h ambulatory blood pressure monitoring in healthy young adult Anglo, Hispanic, and African-American subjects.

    PubMed

    Chase, H P; Garg, S K; Icaza, G; Carmain, J A; Walravens, C F; Marshall, G

    1997-01-01

    The purpose of this study was to compare office and 24-h ambulatory blood pressure (ABP) values for adolescent and young adult males and females of Anglo, Hispanic, and African-American descent. One hundred and eighteen healthy subjects (62 females, 56 males) participated, with an ethnic distribution of 50 Anglo, 32 Hispanic, and 36 African-American subjects. All subjects came to the clinic for height, weight, sitting blood pressure (BP), and to begin 24-h ABP monitoring using the SpaceLabs model 90207 automatic noninvasive monitor. The monitor recorded readings every 0.5 h from 06:00 to 22:00 and every hour at night from 22:00 to 06:00. Office systolic and diastolic BP values were higher for all males compared to all females. Mean 24-h, nighttime, and daytime systolic ABP values were also significantly higher for males compared to females. The 24-h mean and daytime systolic ABP values were significantly different by ethnic groups. The African-American subjects always had the highest readings. Mean 24-h diastolic ABP was also significantly different by ethnic groups, with the African-American subjects being higher than the Anglos or the Hispanics. Diastolic ABP (24-h mean, daytime, and nighttime) values (for all subjects combined) increased gradually and varied significantly with age. This study provides preliminary normative data about ABP in an understudied population (ie, teenagers and young adults of different ethnic backgrounds). It also shows that higher blood pressures are present among males and among subjects of African-American descent in the teenage and young adult population. PMID:9008244

  12. Cost of photovoltaic energy systems as determined by balance-of-system costs

    NASA Technical Reports Server (NTRS)

    Rosenblum, L.

    1978-01-01

    The effect of the balance-of-system (BOS), i.e., the total system less the modules, on photo-voltaic energy system costs is discussed for multikilowatt, flat-plate systems. Present BOS costs are in the range of 10 to 16 dollars per peak watt (1978 dollars). BOS costs represent approximately 50% of total system cost. The possibility of future BOS cost reduction is examined. It is concluded that, given the nature of BOS costs and the lack of comprehensive national effort focussed on cost reduction, it is unlikely that BOS costs will decline greatly in the next several years. This prognosis is contrasted with the expectations of the Department of Energy National Photovoltaic Program goals and pending legislation in the Congress which require a BOS cost reduction of an order of magnitude or more by the mid-1980s.

  13. Satellite remote sensing of surface energy and mass balance - Results from FIFE

    NASA Technical Reports Server (NTRS)

    Hall, F. G.; Markham, B. J.; Wang, J. R.; Huemmrich, F.; Sellers, P. J.; Strebel, D. E.; Kanemasu, E. T.; Kelly, Robert D.; Blad, Blaine L.

    1991-01-01

    Results obtained from the FIFE experiments conducted in 1987 and 1989 are summarized. Data analyses indicate that the hypotheses linking energy balance components to surface biology and remote sensing are reasonable at a point level, and that satellite remote sensing can potentially provide useful estimates of the surface energy budget. An investigation of atmospheric scattering and absorption effects on satellite remote sensing of surface radiance shows that the magnitude of atmospheric opacity variations within the FIFE site and with season can have a large effect on satellite measured values of surface radiances. Comparisons of atmospherically corrected TM radiances with surface measured radiances agreed to within about two percent at the visible and near-infrared wavelengths and to 6 percent in the midinfrared.

  14. Utilization of potatoes for life support systems in space: III. Productivity at successive harvest dates under 12-h and 24-h photoperiods.

    PubMed

    Wheeler, R M; Tibbitts, T W

    1987-01-01

    Potatoes are among several crops under consideration for use in controlled ecological life support systems (CELSS) being proposed for space colonies. Efficient crop production for such life support systems will require near-optimal growing conditions with harvests taken when production per unit area per unit time is maximum. To determine this maximum for potato, cv. Norland plants were grown in walk-in growth rooms under 12-h and 24-h photoperiods at 16 C and harvested at 42, 63, 84, 105, 126 and 148 days from planting. At 42 days, plants were encaged in wire fence cylinders with a cross-sectional area of 0.2 m2. The dry weights (dwt) of tubers and of the entire plants increased under both photoperiods until the final harvest date (148 days), reaching 572 g tuber dwt and 704 g total dwt under 12-h, and 791 g tuber dwt and 972 g total dwt under 24-h. At a spacing of 0.2 m2 per plant, the 148-day tuber production from plants under continuous light would equate to nearly 40 t ha-1 dry matter (200 t fresh weight), approximately twice that of exceptionally high field yields. Tuber productivity (g m-2 day-1) under the 24-h photoperiod reached a maximum of 29.4 g dwt m-2 day-1 at 126 days, but continued to rise throughout the experiment under the 12-h photoperiod, reaching 19.5 g dwt m-2 day-1 at 14 days, approximately 25 m2 would continuously provide the daily dietary energy requirements for one human. PMID:11539685

  15. Long-term energy flux and radiation balance observations over Lake Ngoring, Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Li, Zhaoguo; Lyu, Shihua; Ao, Yinhuan; Wen, Lijuan; Zhao, Lin; Wang, Shaoying

    2015-03-01

    It remains unclear what are the characteristics of the surface energy budget and the radiation balance over the lake at high altitudes. Here we report a nearly two-year ice-free time measurement (2011-2012) of energy flux and radiation balance using the eddy covariance method over Lake Ngoring, Tibetan Plateau. A persistent unstable atmospheric boundary layer was maintained over the lake, caused by a higher water surface temperature compared with the overlying atmosphere. As a result, the positive sensible heat (H) and latent heat (LE) fluxes almost lasted throughout the entire observation period. The heat storage period of the lake could last until September, and the strongest heating occurred in October from the lake to the atmosphere. Compared with the subtropical lake, Bowen ratios were larger in Lake Ngoring, caused by a large temperature difference and a small specific humidity difference between the water surface and the overlying air. The patterns of H versus the atmospheric stability differed from those of LE. H was large under unstable stratification conditions and significantly decreased in the nearly neutral and stable atmospheric stratification. By contrast, the large LE concentrated in the weak unstable to the nearly neutral atmospheric stratification, and clearly declined with increased atmospheric instability. Overall, the vertical specific humidity difference contributed more to LE than the wind speed. As regards H, the major contributors varied with the atmospheric stability. The intrusion of dry, cold air with strong wind could result in significant increases in H and LE (approximately 2.0-4.5 times as much as those of normal days); during this period, the stored energy in water dramatically decreased and even could provide 70% of the energy for H and LE.

  16. Mass and Energy Balances of Dry Thermophilic Anaerobic Digestion Treating Swine Manure Mixed with Rice Straw.

    PubMed

    Zhou, Sheng; Zhang, Jining; Zou, Guoyan; Riya, Shohei; Hosomi, Masaaki

    2015-01-01

    To evaluate the feasibility of swine manure treatment by a proposed Dry Thermophilic Anaerobic Digestion (DT-AD) system, we evaluated the methane yield of swine manure treated using a DT-AD method with rice straw under different C/N ratios and solid retention time (SRT) and calculated the mass and energy balances when the DT-AD system is used for swine manure treatment from a model farm with 1000 pigs and the digested residue is used for forage rice production. A traditional swine manure treatment Oxidation Ditch system was used as the study control. The results suggest that methane yield using the proposed DT-AD system increased with a higher C/N ratio and shorter SRT. Correspondently, for the DT-AD system running with SRT of 80 days, the net energy yields for all treatments were negative, due to low biogas production and high heat loss of digestion tank. However, the biogas yield increased when the SRT was shortened to 40 days, and the generated energy was greater than consumed energy when C/N ratio was 20 : 1 and 30 : 1. The results suggest that with the correct optimization of C/N ratio and SRT, the proposed DT-AD system, followed by using digestate for forage rice production, can attain energy self-sufficiency. PMID:26609436

  17. Mass and energy balances of sludge processing in reference and upgraded wastewater treatment plants.

    PubMed

    Mininni, G; Laera, G; Bertanza, G; Canato, M; Sbrilli, A

    2015-05-01

    This paper describes the preliminary assessment of a platform of innovative upgrading solutions aimed at improving sludge management and resource recovery in wastewater treatment plants. The effectiveness of the upgrading solutions and the impacts of their integration in model reference plants have been evaluated by means of mass and energy balances on the whole treatment plant. Attention has been also paid to the fate of nitrogen and phosphorus in sludge processing and to their recycle back to the water line. Most of the upgrading options resulted in reduced production of dewatered sludge, which decreased from 45 to 56 g SS/(PE × day) in reference plants to 14-49 g SS/(PE × day) in the upgraded ones, with reduction up to 79% when wet oxidation was applied to the whole sludge production. The innovative upgrades generally entail an increased demand of electric energy from the grid, but energy recovery from biogas allowed to minimize the net energy consumption below 10 kWh/(PE × year) in the two most efficient solutions. In all other cases the net energy consumption was in the range of -11% and +28% of the reference scenarios. PMID:25598155

  18. Pyrolysis and gasification of meat-and-bone-meal: energy balance and GHG accounting.

    PubMed

    Cascarosa, Esther; Boldrin, Alessio; Astrup, Thomas

    2013-11-01

    Meat-and-bone-meal (MBM) produced from animal waste has become an increasingly important residual fraction needing management. As biodegradable waste is routed away from landfills, thermo-chemical treatments of MBM are considered promising solution for the future. Pyrolysis and gasification of MBM were assessed based on data from three experimental lab and pilot-scale plants. Energy balances were established for the three technologies, providing different outcomes for energy recovery: bio-oil was the main product for the pyrolysis system, while syngas and a solid fraction of biochar were the main products in the gasification system. These products can be used - eventually after upgrading - for energy production, thereby offsetting energy production elsewhere in the system. Greenhouse gases (GHG) accounting of the technologies showed that all three options provided overall GHG savings in the order of 600-1000kg CO2-eq. per Mg of MBM treated, mainly as a consequence of avoided fossil fuel consumption in the energy sector. Local conditions influencing the environmental performance of the three systems were identified, together with critical factors to be considered during decision-making regarding MBM management. PMID:23916845

  19. The fluctuation energy balance in non-suspended fluid-mediated particle transport

    SciTech Connect

    Pähtz, Thomas; Durán, Orencio; Ho, Tuan-Duc; Valance, Alexandre; Kok, Jasper F.

    2015-01-15

    Here, we compare two extreme regimes of non-suspended fluid-mediated particle transport, transport in light and heavy fluids (“saltation” and “bedload,” respectively), regarding their particle fluctuation energy balance. From direct numerical simulations, we surprisingly find that the ratio between collisional and fluid drag dissipation of fluctuation energy is significantly larger in saltation than in bedload, even though the contribution of interparticle collisions to transport of momentum and energy is much smaller in saltation due to the low concentration of particles in the transport layer. We conclude that the much higher frequency of high-energy particle-bed impacts (“splash”) in saltation is the cause for this counter-intuitive behavior. Moreover, from a comparison of these simulations to particle tracking velocimetry measurements which we performed in a wind tunnel under steady transport of fine and coarse sand, we find that turbulent fluctuations of the flow produce particle fluctuation energy at an unexpectedly high rate in saltation even under conditions for which the effects of turbulence are usually believed to be small.

  20. Balancing energy development and conservation: A method utilizing species distribution models

    USGS Publications Warehouse

    Jarnevich, C.S.; Laubhan, M.K.

    2011-01-01

    Alternative energy development is increasing, potentially leading to negative impacts on wildlife populations already stressed by other factors. Resource managers require a scientifically based methodology to balance energy development and species conservation, so we investigated modeling habitat suitability using Maximum Entropy to develop maps that could be used with other information to help site energy developments. We selected one species of concern, the Lesser Prairie-Chicken (LPCH; Tympanuchus pallidicinctus) found on the southern Great Plains of North America, as our case study. LPCH populations have been declining and are potentially further impacted by energy development. We used LPCH lek locations in the state of Kansas along with several environmental and anthropogenic parameters to develop models that predict the probability of lek occurrence across the landscape. The models all performed well as indicated by the high test area under the curve (AUC) scores (all >0.9). The inclusion of anthropogenic parameters in models resulted in slightly better performance based on AUC values, indicating that anthropogenic features may impact LPCH lek habitat suitability. Given the positive model results, this methodology may provide additional guidance in designing future survey protocols, as well as siting of energy development in areas of marginal or unsuitable habitat for species of concern. This technique could help to standardize and quantify the impacts various developments have upon at-risk species. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

  1. Mass and Energy Balances of Dry Thermophilic Anaerobic Digestion Treating Swine Manure Mixed with Rice Straw

    PubMed Central

    Zhou, Sheng; Zhang, Jining; Zou, Guoyan; Riya, Shohei; Hosomi, Masaaki

    2015-01-01

    To evaluate the feasibility of swine manure treatment by a proposed Dry Thermophilic Anaerobic Digestion (DT-AD) system, we evaluated the methane yield of swine manure treated using a DT-AD method with rice straw under different C/N ratios and solid retention time (SRT) and calculated the mass and energy balances when the DT-AD system is used for swine manure treatment from a model farm with 1000 pigs and the digested residue is used for forage rice production. A traditional swine manure treatment Oxidation Ditch system was used as the study control. The results suggest that methane yield using the proposed DT-AD system increased with a higher C/N ratio and shorter SRT. Correspondently, for the DT-AD system running with SRT of 80 days, the net energy yields for all treatments were negative, due to low biogas production and high heat loss of digestion tank. However, the biogas yield increased when the SRT was shortened to 40 days, and the generated energy was greater than consumed energy when C/N ratio was 20 : 1 and 30 : 1. The results suggest that with the correct optimization of C/N ratio and SRT, the proposed DT-AD system, followed by using digestate for forage rice production, can attain energy self-sufficiency. PMID:26609436

  2. Water and energy balance in a Mediterranean snowpack: the importance of evaposublimation

    NASA Astrophysics Data System (ADS)

    Herrero, Javier; Pimentel, Rafael; María José, Pérez-Palazón; María José, Polo

    2016-04-01

    In low-latitude snowpacks or those located in semiarid regions, snow dynamics becomes an essential driver of the hydrological cycle, as well as an important support for a number of ecosystem services with an influence over the economy and the ecology of the whole region. Therefore, it is crucial to understand the processes that are taking place in the snowpack and the relative importance and timing of the different mass and energy fluxes. Sierra Nevada is a linear mountain range parallel to the Mediterranean coastline of southern Spain at 37°N. It reaches up to 3479 m.a.s.l. in approximately 40 km from the sea. Despite the semiarid climatic conditions that surround the high mountain area, it presents a regular snow cover above 2500 m.a.s.l. during the winter season. Previous studies have shown at this site that this snowpack is very exposed to high insolation rates and strong winds, and, like in other low-latitude areas, the radiative and evaposublimation (combination of the sublimation of ice and the evaporation of the water drops melted on the surface of the snow) fluxes may have a significant and prominent value in the coupled balance. In this work, we study the evaposublimation fraction in the annual water and energy balance over the snowpack in Sierra Nevada. For this, we apply a one-layer mass and energy balance snow model developed in previous works, which has proven to adequately simulate the shallow snowpacks of Sierra Nevada during the year. High evaposublimation rates were simulated and subsequently measured during several field campaigns. Evaposublimation fractions were found to range from 24 to 33% of the total annual ablation at this site. This ratio is very changeable between years, like the local meteorology itself, even though there was not a direct relationship between this rate and the dry or humid nature of each particular year. In fact, it is the particular distribution of the rainfall throughout the year what defines the dynamics of the

  3. Effects of AgRP inhibition on energy balance and metabolism in rodent models.

    PubMed

    Dutia, Roxanne; Kim, Andrea J; Modes, Matthew; Rothlein, Robert; Shen, Jane M; Tian, Ye Edward; Ihbais, Jumana; Victory, Sam F; Valcarce, Carmen; Wardlaw, Sharon L

    2013-01-01

    Activation of brain melanocortin-4 receptors (MC4-R) by α-melanocyte-stimulating hormone (MSH) or inhibition by agouti-related protein (AgRP) regulates food intake and energy expenditure and can modulate neuroendocrine responses to changes in energy balance. To examine the effects of AgRP inhibition on energy balance, a small molecule, non-peptide compound, TTP2515, developed by TransTech Pharma, Inc., was studied in vitro and in rodent models in vivo. TTP2515 prevented AgRP from antagonizing α-MSH-induced increases in cAMP in HEK 293 cells overexpressing the human MC4-R. When administered to rats by oral gavage TTP2515 blocked icv AgRP-induced increases in food intake, weight gain and adiposity and suppression of T4 levels. In both diet-induced obese (DIO) and leptin-deficient mice, TTP2515 decreased food intake, weight gain, adiposity and respiratory quotient. TTP2515 potently suppressed food intake and weight gain in lean mice immediately after initiation of a high fat diet (HFD) but had no effect on these parameters in lean chow-fed mice. However, when tested in AgRP KO mice, TTP2515 also suppressed food intake and weight gain during HFD feeding. In several studies TTP2515 increased T4 but not T3 levels, however this was also observed in AgRP KO mice. TTP2515 also attenuated refeeding and weight gain after fasting, an effect not evident in AgRP KO mice when administered at moderate doses. This study shows that TTP2515 exerts many effects consistent with AgRP inhibition however experiments in AgRP KO mice indicate some off-target effects of this drug. TTP2515 was particularly effective during fasting and in mice with leptin deficiency, conditions in which AgRP is elevated, as well as during acute and chronic HFD feeding. Thus the usefulness of this drug in treating obesity deserves further exploration, to define the AgRP dependent and independent mechanisms by which TTP2515 exerts its effects on energy balance. PMID:23762342

  4. Two-source energy balance model implementation in the Alaska Arctic tundra

    NASA Astrophysics Data System (ADS)

    Cristóbal-Rosselló, J.; Prakash, A.; Anderson, M. C.; Kustas, W. P.; Kane, D. L.

    2014-12-01

    Evaporation and transpiration are the two main processes involved in water transfer from vegetated and non-vegetated areas to the atmosphere. Evapotranspiration (ET) from the Earth's vegetation constitutes 88% of the total terrestrial ET, and returns more than 50% of terrestrial precipitation to the atmosphere (Oki and Kane, 2006); therefore it plays a key role in both the hydrological cycle and the energy balance of the land surface. In Arctic regions, surface-atmosphere exchanges due to ET are estimated from water balance computations to be about 74% of summer precipitation or 50% of annual precipitation. Even though ET is a significant component of the hydrologic cycle in this region, these bulk estimates do not accurately account for spatial and temporal variability due to vegetation type, topography, etc. (Kane and Yang, 2004). In this work we present the implementation of the Two-Source Energy Balance method, TSEB (Norman et al., 1995), in two Alaska Arctic tundra settings, as a base-line to retrieve energy fluxes at the regional scale from remote sensing imagery. In order to calibrate and validate the model, four flux towers located at the Imanvait Creek and the Anaktuvuk river were used. The TSEB model mainly requires meteorological inputs as well as land surface temperature (LST) and leaf area index (LAI) data. In this study, TSEB was run from late May to early September from 2008 to 2011 in all sky conditions using half hour intervals of meteorological data from the flux tower, and the LST derived from the four component net radiation instrument. TERRA/AQUA MODIS LAI daily product (MOD15/MYD15) was used as LAI input data. Results show an acceptable agreement between the TSEB model and flux tower data. RMSE obtained in the case of net radiation, latent heat, sensible heat and soil heat fluxes was 12, 51, 60 and 27 W/m2. Further efforts will be focused on the daily energy flux integration through implementation of the DTD model (Norman et al., 2000).

  5. CUES - A Study Site for Measuring Snowpack Energy Balance in the Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Bair, Edward; Dozier, Jeff; Davis, Robert; Colee, Michael; Claffey, Keran

    2015-09-01

    Accurate measurement and modeling of the snowpack energy balance are critical to understanding the terrestrial water cycle. Most of the water resources in the western US come from snowmelt, yet statistical runoff models that rely on the historical record are becoming less reliable because of a changing climate. For physically based snow melt models that do not depend on past conditions, ground based measurements of the energy balance components are imperative for verification. For this purpose, the US Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) and the University of California, Santa Barbara (UCSB) established the “CUES” snow study site (CRREL/UCSB Energy Site, http://www.snow.ucsb.edu/) at 2940 m elevation on Mammoth Mountain, California. We describe CUES, provide an overview of research, share our experience with scientific measurements, and encourage future collaborative research. Snow measurements began near the current CUES site for ski area operations in 1969. In the 1970s, researchers began taking scientific measurements. Today, CUES benefits from year round gondola access and a fiber optic internet connection. Data loggers and computers automatically record and store over 100 measurements from more than 50 instruments each minute. CUES is one of only five high altitude mountain sites in the Western US where a full suite of energy balance components are measured. In addition to measuring snow on the ground at multiple locations, extensive radiometric and meteorological measurements are recorded. Some of the more novel measurements include scans by an automated terrestrial LiDAR, passive and active microwave imaging of snow stratigraphy, microscopic imaging of snow grains, snowflake imaging with a multi-angle camera, fluxes from upward and downward looking radiometers, snow water equivalent from different types of snow pillows, snowmelt from lysimeters, and concentration of impurities in the snowpack. We give an

  6. Quality assurance of the international computerised 24 h dietary recall method (EPIC-Soft).

    PubMed

    Crispim, Sandra P; Nicolas, Genevieve; Casagrande, Corinne; Knaze, Viktoria; Illner, Anne-Kathrin; Huybrechts, Inge; Slimani, Nadia

    2014-02-01

    The interview-administered 24 h dietary recall (24-HDR) EPIC-Soft® has a series of controls to guarantee the quality of dietary data across countries. These comprise all steps that are part of fieldwork preparation, data collection and data management; however, a complete characterisation of these quality controls is still lacking. The present paper describes in detail the quality controls applied in EPIC-Soft, which are, to a large extent, built on the basis of the EPIC-Soft error model and are present in three phases: (1) before, (2) during and (3) after the 24-HDR interviews. Quality controls for consistency and harmonisation are implemented before the interviews while preparing the seventy databases constituting an EPIC-Soft version (e.g. pre-defined and coded foods and recipes). During the interviews, EPIC-Soft uses a cognitive approach by helping the respondent to recall the dietary intake information in a stepwise manner and includes controls for consistency (e.g. probing questions) as well as for completeness of the collected data (e.g. system calculation for some unknown amounts). After the interviews, a series of controls can be applied by dietitians and data managers to further guarantee data quality. For example, the interview-specific 'note files' that were created to track any problems or missing information during the interviews can be checked to clarify the information initially provided. Overall, the quality controls employed in the EPIC-Soft methodology are not always perceivable, but prove to be of assistance for its overall standardisation and possibly for the accuracy of the collected data. PMID:24001201

  7. Parabens in 24 h urine samples of the German Environmental Specimen Bank from 1995 to 2012.

    PubMed

    Moos, Rebecca K; Koch, Holger M; Angerer, Jürgen; Apel, Petra; Schröter-Kermani, Christa; Brüning, Thomas; Kolossa-Gehring, Marike

    2015-10-01

    Parabens are widely used as antimicrobial preservatives in personal care and consumer products, food and pharmaceuticals. Due to their ubiquity, humans are constantly exposed to these chemicals. We assessed exposure to nine parabens (methyl-, ethyl-, n- and iso-propyl-, n- and iso-butyl-, benzyl-, pentyl- and heptyl paraben) in the German population from 1995 to 2012 based on 660 24h urine samples from the German Environmental Specimen Bank (ESB) using on-line HPLC coupled to isotope dilution tandem mass spectrometry. The limit of quantification (LOQ) was 0.5 μg/L for all parabens. We detected methyl-, ethyl- and n-propyl paraben in 79-99% of samples, followed by n-butyl paraben in 40% of samples. We infrequently detected iso-butyl-, iso-propyl- and benzyl paraben in 24%, 4% and 1.4% of samples, respectively. Urinary concentrations were highest for methyl paraben (median 39.8 μg/L; 95th percentile 319 μg/L) followed by n-propyl paraben (4.8 μg/L; 95th percentile 74.0 μg/L) and ethyl paraben (2.1 μg/L; 95th percentile 39.1 μg/L). Women had significantly higher urinary levels for all parabens than men, except for benzyl paraben. Samples from the ESB revealed that over the investigation period of nearly 20 years urinary paraben levels remained surprisingly constant; only methyl paraben had a significant increase, for both men and women. We found strong correlations between methyl- and n-propyl paraben and between n- and iso-butyl paraben. These results indicate that parabens are used in combination and arise from common sources of exposure. Urinary excretion factors are needed to extrapolate from individual urinary concentrations to actual doses. PMID:26253560

  8. Postmortem redistribution of the heroin metabolites morphine and morphine-3-glucuronide in rabbits over 24 h.

    PubMed

    Maskell, Peter D; Albeishy, Mohammed; De Paoli, Giorgia; Wilson, Nathan E; Seetohul, L Nitin

    2016-03-01

    The interpretation of postmortem drug levels is complicated by changes in drug blood levels in the postmortem period, a phenomena known as postmortem drug redistribution. We investigated the postmortem redistribution of the heroin metabolites morphine and morphine-3-glucuronide in a rabbit model. Heroin (1 mg/kg) was injected into anesthetised rabbit; after 1 h, an auricular vein blood sample was taken and the rabbit was euthanised. Following death rabbits were placed in a supine position at room temperature and divided into three groups namely (1) immediate autopsy, (2) autopsy after 30 minutes and (3) autopsy 24 h after death. Various samples which included femoral blood, cardiac blood, lung, liver, kidney, vitreous humour, subcutaneous and abdominal fat, liver, bone marrow and skeletal muscle were taken. The samples were analysed with a validated LC-MS/MS method. It was observed that within minutes there was a significant increase in free morphine postmortem femoral blood concentration compared to the antemortem sample (0.01 ± 0.01 to 0.05 ± 0.02 mg/L).Various other changes in free morphine and metabolite concentrations were observed during the course of the experiment in various tissues. Principal component analysis was used to investigate possible correlations between free morphine in the various samples. Some correlations were observed but gave poor predictions (>20 % error) when back calculating. The results suggest that rabbits are a good model for further studies of postmortem redistribution but that further study and understanding of the phenomena is required before accurate predictions of the blood concentration at the time of death are possible. PMID:25863436

  9. Effects of decreased dietary roughage concentration on energy metabolism and nutrient balance in finishing beef cattle.

    PubMed

    Hales, K E; Brown-Brandl, T M; Freetly, H C

    2014-01-01

    The optimal roughage concentration required in feedlot diets changes continuously for many reasons such as source, availability, price, and interaction with other ingredients in the diet. Wet distillers grains and solubles (WDGS) are common in finishing diets and they contain relatively high amounts of fiber compared with other grains they replace. Therefore, concentration of roughage could be altered when WDGS are included in feedlot diets. There has been very little data published regarding the effects of roughage concentration on energy metabolism and nutrient balance in beef steers. Therefore, the effects of roughage concentration in dry-rolled corn (DRC)-based diets containing 25% WDGS were evaluated in 8 steers (BW = 362 ± 3.71 kg) using a replicated Latin square. Data were analyzed with the fixed effects of dietary treatment and period and random effects of square and steer within square were included in the model. Diets consisted of 25% WDGS and the balance being DRC and coarsely ground alfalfa hay (AH) replacing corn at 2% (AH-2), 6% (AH-6), 10% (AH-10), and 14% (AH-14) of dietary dry matter. As a proportion of GE intake, fecal energy loss increased linearly (P = 0.02), and DE decreased linearly (P = 0.02) as dietary level of AH increased. Methane energy loss, as a proportion of GE intake, increased linearly (P < 0.01) and ME decreased linearly (P < 0.01) as dietary concentration of AH increased. Heat production tended (P = 0.10) to decrease reaching a minimum of 10% AH and increased from 10 to 14% AH inclusion. Moreover, as a proportion of GE intake, retained energy (RE) decreased (P < 0.01) as AH level increased in the diet. Reasons for the decrease in RE are 1) the increase in fecal energy loss that is associated with decreased ruminal digestibility of NDF when AH replaced DRC and the shift in ruminal VFA produced, 2) the decreased energy available for animal retention when NDF increased linearly as AH increased in the diet, and 3) the methane and heat

  10. Estimating the actual ET from a pecan farm using the OPEC energy-balance and Penman- Monteith methods

    NASA Astrophysics Data System (ADS)

    Debele, B.; Bawazir, S. A.

    2006-12-01

    Accurate estimation of ET from field crops/orchards is the basis for better irrigation water management. In areas like Mesilla Valley, NM, where water is scarce, it is even more important to precisely determine the crop ET. An OPEC energy balance system was run for 117 days (June 22 October 14, 2001) in a matured pecan farm at Mesilla Valley, NM. The actual evapotranspiration (ET) from pecan orchards was determined from the surface energy balance as a residual, having measured the net radiation, soil heat flux, and sensible heat components using the OPEC method. Since pecans are large trees, we have also examined the effect of including thermal energies stored in the air (Ga) and plant canopy (Gc), on top of the commonly used thermal energy stored in the soil (Gs), on surface energy balance, and hence ET. The results indicate that incorporating thermal energies stored in the air and canopy has a significant effect on total energy storage for shorter temporal resolutions, such as 30-minutes and an hour. Conversely, for longer temporal resolutions (e.g., diurnal and monthly averages), the effect of including thermal energies stored in the air and vegetation on total thermal energy storage is negligible. Our results also showed that the bulk of the total thermal energy storage (G = Gs + Ga + Gc) in the surface energy balance was stored in the soil (Gs). In addition, we have also determined the crop coefficient (Kc) of pecan by combining the actual ET obtained from the OPEC method and potential ET (ET0) calculated using weather data in the surrounding area. Our average pecan Kc values were comparable with the ones reported by other researchers using different methods. We conclude that the OPEC energy balance method can be used to calculate Kc values for pecan whereby farmers and extension agents use the calculated Kc values in combination with ET0 to determine the consumptive use of pecan trees.

  11. Evaluating ET estimates from the Simplified Surface Energy Balance (SSEB) model using METRIC model output

    NASA Astrophysics Data System (ADS)

    Senay, G. B.; Budde, M. E.; Allen, R. G.; Verdin, J. P.

    2008-12-01

    Evapotranspiration (ET) is an important component of the hydrologic budget because it expresses the exchange of mass and energy between the soil-water-vegetation system and the atmosphere. Since direct measurement of ET is difficult, various modeling methods are used to estimate actual ET (ETa). Generally, the choice of method for ET estimation depends on the objective of the study and is further limited by the availability of data and desired accuracy of the ET estimate. Operational monitoring of crop performance requires processing large data sets and a quick response time. A Simplified Surface Energy Balance (SSEB) model was developed by the U.S. Geological Survey's Famine Early Warning Systems Network to estimate irrigation water use in remote places of the world. In this study, we evaluated the performance of the SSEB model with the METRIC (Mapping Evapotranspiration at high Resolution and with Internalized Calibration) model that has been evaluated by several researchers using the Lysimeter data. The METRIC model has been proven to provide reliable ET estimates in different regions of the world. Reference ET fractions of both models (ETrF of METRIC vs. ETf of SSEB) were generated and compared using individual Landsat thermal images collected from 2000 though 2005 in Idaho, New Mexico, and California. In addition, the models were compared using monthly and seasonal total ETa estimates. The SSEB model reproduced both the spatial and temporal variability exhibited by METRIC on land surfaces, explaining up to 80 percent of the spatial variability. However, the ETa estimates over water bodies were systematically higher in the SSEB output, which could be improved by using a correction coefficient to take into account the absorption of solar energy by deeper water layers that has little contribution to the ET process. This study demonstrated the usefulness of the SSEB method for large-scale agro-hydrologic applications for operational monitoring and assessing of

  12. Energy and mass balance at the snow surface on a warm temperate mountain

    NASA Astrophysics Data System (ADS)

    Sade, Rotem; Rimmer, Alon; (Iggy) Litaor, Michael; Furman, Alex

    2014-05-01

    Snowmelt is an important water source in warm temperate mountains, where natural fresh water sources are often scarce, and vapor losses from the snow-surface can greatly limit water availability. Therefore, understanding of key processes of snow dynamics in such environment is highly important. To achieve this end, we estimated the energy and mass balance of the snowpack on Mt. Hermon, Israel (35o50'E, 33o25'N), using a snow model. The forcing variables for the simulations were collected in two meteorological stations located along altitudinal gradient at 1,640 and 1,960m. We simulated the snowpack energy and mass balance during the winter of 2010/11 in a Deep Snowpack (DSP; maximum depth of 7m), and in a karstic depression known as the 'Bulan', where both windswept locations and lee-side (DSP) locations were simulated. The calibrat