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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. 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

    2016-01-15

    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.

  3. 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.

  4. Effect of moderate cold exposure on 24-h energy expenditure: similar response in postobese and nonobese women.

    PubMed

    Buemann, B; Astrup, A; Christensen, N J; Madsen, J

    1992-12-01

    Twenty-four-hour energy expenditure (EE) and substrate oxidation rates were measured two times in eight postobese women and eight matched controls. On one occasion the subjects were exposed to a room temperature of 16 degrees C, on the other to 24 degrees C. Cold exposure elicited a 2% increment in 24-h EE (P < 0.05), with similar response in the two groups. The slight increase in EE was entirely covered by an enhanced carbohydrate oxidation rate. Fasting plasma norepinephrine (NE) increased from 0.74 +/- 0.08 to 1.29 +/- 0.21 nmol/l under cold exposure (P < 0.05), with no group difference. The cold-induced increase in 24-h EE was positively correlated to the increase in NE concentration (r2 = 0.41, P = 0.01). Sleeping EE was found to be 5% lower in the postobese women than in the controls (P = 0.04). The postobese group also had higher 24-h nonprotein respiratory quotient than the control group (P = 0.04), which was due to a 26% lower lipid-to-carbohydrate oxidation ratio. The study demonstrates that the thermogenic response to cold is normal in women susceptible to obesity, but it supports previous reports of a slightly lower basal EE and lower lipid-to-carbohydrate oxidation ratio in postobese subjects.

  5. Ingestion of nutrition bars high in protein or carbohydrate does not impact 24-h energy intakes in healthy young adults.

    PubMed

    Trier, Catherine M; Johnston, Carol S

    2012-12-01

    Sales of nutrition bars increased almost 10-fold to $1.7billion over the past decade yet few studies have examined the impact of bar ingestion on dietary parameters. In this crossover trial, 24-h energy intakes were assessed in free-living college students ingesting a high-protein (HP, 280kcal) or a high-carbohydrate (HC, 260kcal) nutrition bar upon waking. Fifty-four students entered the trial, and 37 participants completed the three test days. Daily energy intakes ranged from 1752±99kcal for the non-intervention day to 1846±75 and 1891±110kcal for the days the HP and HC bars were consumed respectively (p=0.591). However, for individuals who reported high levels of physically activity (n=11), daily energy intakes increased significantly compared to the control day for the HC bar day (+45%; p=0.030) and HP bar day (+22%; p=0.038). Macro- and micro-nutrient intakes differed significantly across test days in the total sample mirroring the nutrient profile of the specific bars. These data suggest that young adults adjust caloric intakes appropriately following the ingestion of energy-dense nutrition bars over a 24-h period. Moreover, nutrition bars may represent a unique opportunity to favorably influence nutrient status of young adults.

  6. 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...

  7. 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

  8. Reproducibility of 24-h post-exercise changes in energy intake in overweight and obese women using current methodology.

    PubMed

    Brown, Gemma L; Lean, Michael E; Hankey, Catherine R

    2012-07-01

    Direct observation(s) of energy intake (EI) via buffet meals served in the laboratory are often carried out within short-term exercise intervention studies. The reproducibility of values obtained has not been assessed either under resting control conditions or post-exercise, in overweight and obese females. A total of fourteen sedentary, pre-menopausal females (BMI 30.0 (SD 5.1) kg/m²) completed four trials; two exercise and two control. Each trial lasted 24 h spanning over 2 d; conducted from afternoon on day 1 and morning on day 2. An exercise session to expend 1.65 MJ was completed on day 1 of exercise trials, and three buffet meals were served during each trial. Reproducibility of post-exercise changes in energy and macronutrient intakes was assessed at each individual buffet meal by intraclass correlation coefficient (r(i)). Only the r(i) values for post-exercise changes in energy (r(i) 0.44 (95 % CI - 0.03, 0.77), P = 0.03) and fat intake (r(i) 0.51 (95 % CI 0.04, 0.81), P = 0.02) at the lunch buffet meal achieved statistical significance; however, these r i values were weak and had large associated 95 % CI, which indicates a large degree of variability associated with these measurements. Energy and macronutrient intakes at the breakfast and evening buffet meals were not reproducible. This study concludes that the frequently used laboratory-based buffet meal method of assessing EI does not produce reliable, reproducible post-exercise changes in EI in overweight and obese women.

  9. 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)

  10. 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...

  11. Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men.

    PubMed

    Bérubé-Parent, Sonia; Pelletier, Catherine; Doré, Jean; Tremblay, Angelo

    2005-09-01

    It has been reported that green tea has a thermogenic effect, due to its caffeine content and probably also to the catechin, epigallocatechin-3-gallate (EGCG). The main aim of the present study was to compare the effect of a mixture of green tea and Guarana extracts containing a fixed dose of caffeine and variable doses of EGCG on 24 h energy expenditure and fat oxidation. Fourteen subjects took part to this randomized, placebo-controlled, double-blind, cross-over study. Each subject was tested five times in a metabolic chamber to measure 24 h energy expenditure, substrate oxidation and blood pressure. During each stay, the subjects ingested a capsule of placebo or capsules containing 200 mg caffeine and a variable dose of EGCG (90, 200, 300 or 400 mg) three times daily, 30 min before standardized meals. Twenty-four hour energy expenditure increased significantly by about 750 kJ with all EGCG-caffeine mixtures compared with placebo. No effect of the EGCG-caffeine mixture was observed for lipid oxidation. Systolic and diastolic blood pressure increased by about 7 and 5 mmHg, respectively, with the EGCG-caffeine mixtures compared with placebo. This increase was significant only for 24 h diastolic blood pressure. The main finding of the study was the increase in 24 h energy expenditure with the EGCG-caffeine mixtures. However, this increase was similar with all doses of EGCG in the mixtures.

  12. 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

  13. 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.

  14. 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)

  15. 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.

  16. Exercise Increases 24-h Fat Oxidation Only When It Is Performed Before Breakfast

    PubMed Central

    Iwayama, Kaito; Kurihara, Reiko; Nabekura, Yoshiharu; Kawabuchi, Ryosuke; Park, Insung; Kobayashi, Masashi; Ogata, Hitomi; Kayaba, Momoko; Satoh, Makoto; Tokuyama, Kumpei

    2015-01-01

    Background As part of the growing lifestyle diversity in modern society, there is wide variation in the time of day individuals choose to exercise. Recent surveys in the US and Japan have reported that on weekdays, more people exercise in the evening, with fewer individuals exercising in the morning or afternoon. Exercise performed in the post-prandial state has little effect on accumulated fat oxidation over 24 h (24-h fat oxidation) when energy intake is matched to energy expenditure (energy-balanced condition). The present study explored the possibility that exercise increases 24-h fat oxidation only when performed in a post-absorptive state, i.e. before breakfast. Methods Indirect calorimetry using a metabolic chamber was performed in 10 young, non-obese men over 24 h. Subjects remained sedentary (control) or performed 60-min exercise before breakfast (morning), after lunch (afternoon), or after dinner (evening) at 50% of VO2max. All trials were designed to be energy balanced over 24 h. Time course of energy and substrate balance relative to the start of calorimetry were estimated from the differences between input (meal consumption) and output (oxidation). Findings Fat oxidation over 24 h was increased only when exercise was performed before breakfast (control, 456 ± 61; morning, 717 ± 64; afternoon, 446 ± 57; and evening, 432 ± 44 kcal/day). Fat oxidation over 24 h was negatively correlated with the magnitude of the transient deficit in energy and carbohydrate. Interpretation Under energy-balanced conditions, 24-h fat oxidation was increased by exercise only when performed before breakfast. Transient carbohydrate deficits, i.e., glycogen depletion, observed after morning exercise may have contributed to increased 24-h fat oxidation. PMID:26844280

  17. 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.

  18. 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.

  19. Alcohol from corn: poor energy balance

    SciTech Connect

    Not Available

    1981-08-10

    It is reported that most processing plants producing alcohol from corn currently operate with very unfavourable energy balances. The energy needed to grow and harvest corn plus petroleum or natural gas used in the processing phase often exceeds the energy that can be derived from the alcohol.

  20. PV modules with optimized energy balance

    NASA Astrophysics Data System (ADS)

    Weixlberger, Johann; Bruckner, Richard

    2011-09-01

    The overall energy balance of a solar PV-module across its life time needs a consideration incl. its energy consumption during manufacturing process versus its energy harvesting capabilities during life time. A glass-glass-module based on thin tempered glass on front and backside can dramatically influence this overall balance, since more than 50 % of encapsulation materials manufacturing energy can be saved, followed by a an further impact on frameless mounting of light-weighted modules, reducing mounting costs and enabling simpler BIPV.

  1. 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.

  2. When energy balance is maintained, exercise does not induce negative fat balance in lean sedentary, obese sedentary, or lean endurance-trained individuals

    PubMed Central

    Gozansky, Wendolyn S.; Barry, Daniel W.; MacLean, Paul S.; Grunwald, Gary K.; Hill, James O.

    2009-01-01

    Fat oxidation during exercise is increased by endurance training, and evidence suggests that fat oxidation during exercise is impaired in obesity. Thus the primary aim of this study was to compare the acute effects of exercise on 24-h fat oxidation and fat balance in lean sedentary [LS, n = 10, body mass index (BMI) = 22.5 ± 6.5 kg/m2], lean endurance-trained (LT, n = 10, BMI = 21.2 ± 1.2 kg/m2), and obese sedentary (OS, n = 7, BMI = 35.5 ± 4.4 kg/m2) men and women. Twenty-four-hour energy expenditure and substrate oxidation were measured under sedentary (control; CON) and exercise (EX) conditions while maintaining energy balance. During EX, subjects performed 1 h of stationary cycling at 55% of aerobic capacity. Twenty-four-hour fat oxidation did not differ on the CON or EX day in LS (43 ± 9 vs. 29 ± 7 g/day, respectively), LT (53 ± 8 vs. 42 ± 5 g/day), or OS (58 ± 7 vs. 80 ± 9 g/day). However, 24-h fat balance was significantly more positive on EX compared with CON (P < 0.01). Twenty-four-hour glucose, insulin, and free fatty acid (FFA) profiles were similar on the EX and CON days, but after consumption of the first meal, FFA concentrations remained below fasting levels for the remainder of the day. These data suggest that when exercise is performed with energy replacement (i.e., energy balance is maintained), 24-h fat oxidation does not increase and in fact, may be slightly decreased. It appears that the state of energy balance is an underappreciated factor determining the impact of exercise on fat oxidation. PMID:19833807

  3. Glial cells and energy balance.

    PubMed

    Argente-Arizón, Pilar; Guerra-Cantera, Santiago; Garcia-Segura, Luis Miguel; Argente, Jesús; Chowen, Julie A

    2017-01-01

    The search for new strategies and drugs to abate the current obesity epidemic has led to the intensification of research aimed at understanding the neuroendocrine control of appetite and energy expenditure. This intensified investigation of metabolic control has also included the study of how glial cells participate in this process. Glia, the most abundant cell type in the central nervous system, perform a wide spectrum of functions and are vital for the correct functioning of neurons and neuronal circuits. Current evidence indicates that hypothalamic glia, in particular astrocytes, tanycytes and microglia, are involved in both physiological and pathophysiological mechanisms of appetite and metabolic control, at least in part by regulating the signals reaching metabolic neuronal circuits. Glia transport nutrients, hormones and neurotransmitters; they secrete growth factors, hormones, cytokines and gliotransmitters and are a source of neuroprogenitor cells. These functions are regulated, as glia also respond to numerous hormones and nutrients, with the lack of specific hormonal signaling in hypothalamic astrocytes disrupting metabolic homeostasis. Here, we review some of the more recent advances in the role of glial cells in metabolic control, with a special emphasis on the differences between glial cell responses in males and females.

  4. 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.

  5. Exercise patterns, ingestive behaviors, and energy balance.

    PubMed

    Li, Jia; O'Connor, Lauren E; Zhou, Jing; Campbell, Wayne W

    2014-07-01

    Ingestive and exercise behaviors are important determinants of whole body energy balance and weight control. An acute bout of exercise generates a transient energy deficit, which is only partially compensated for by food intake at the next eating occasion or within the next day (loose dietary coupling). Such an energy deficit, when repeated chronically, leads to moderate weight loss and improved body composition. For this narrative review, we assessed the effects of exercise patterns on energy intake, energy balance, and weight control in adults primarily using results from randomized acute exercise and chronic training studies. The patterns assessed were exercise mode (e.g. resistance, aerobic exercise), intensity, duration, time of day, and frequency. The body of evidence indicates that exercise training frequency and quantity are influential for weight loss. Aerobic training is superior to resistance training for weight loss, although resistance training helps preserve lean body mass better. Weight loss does not differ among different intensities when energy expenditure is matched by adjusting duration. Differing patterns of physical activity exhibited by normal weight, overweight, and obese people during weekdays and weekend days are consistent with their weight status; leaner people are more physically active. Collectively, these findings support acute and chronic exercise patterns as important modifiable behaviors to improve energy balance and weight control in adults while having minor effects on absolute energy intake.

  6. An energy balance concept for habitability.

    PubMed

    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.

  7. Kisspeptin and energy balance in reproduction.

    PubMed

    De Bond, Julie-Ann P; Smith, Jeremy T

    2014-03-01

    Kisspeptin is vital for the neuroendocrine regulation of GNRH secretion. Kisspeptin neurons are now recognized as a central pathway responsible for conveying key homeostatic information to GNRH neurons. This pathway is likely to mediate the well-established link between energy balance and reproductive function. Thus, in states of severely altered energy balance (either negative or positive), fertility is compromised, as is Kiss1 expression in the arcuate nucleus. A number of metabolic modulators have been proposed as regulators of kisspeptin neurons including leptin, ghrelin, pro-opiomelanocortin (POMC), and neuropeptide Y (NPY). Whether these regulate kisspeptin neurons directly or indirectly will be discussed. Moreover, whether the stimulatory role of leptin on reproduction is mediated by kisspeptin directly will be questioned. Furthermore, in addition to being expressed in GNRH neurons, the kisspeptin receptor (Kiss1r) is also expressed in other areas of the brain, as well as in the periphery, suggesting alternative roles for kisspeptin signaling outside of reproduction. Interestingly, kisspeptin neurons are anatomically linked to, and can directly excite, anorexigenic POMC neurons and indirectly inhibit orexigenic NPY neurons. Thus, kisspeptin may have a direct role in regulating energy balance. Although data from Kiss1r knockout and WT mice found no differences in body weight, recent data indicate that kisspeptin may still play a role in food intake and glucose homeostasis. Thus, in addition to regulating reproduction, and mediating the effect of energy balance on reproductive function, kisspeptin signaling may also be a direct regulator of metabolism.

  8. Nexus of poverty, energy balance and health.

    PubMed

    Mishra, C P

    2012-04-01

    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

  9. Energy balance of the collisional tearing mode

    SciTech Connect

    Bondeson, A.; Sobel, J.R.

    1984-08-01

    The energy balance of the collisional tearing mode is examined within linear theory. It is found that in an asymmetric case the quadratic form given by Furth for the net release of magnetic energy must be completed with a term connected with the current gradient in the resistive layer. The growth-rate and the inner-layer solution are calculated in the limit where viscosity dominates over inertia. The amounts of energy going into Joule heating and either kinetic energy or viscous dissipation are calculated analytically. In the inertial regime 1/4 of the net decrease in magnetic energy goes into kinetic energy and (3)/(4) into Joule heating, while, in viscous regime, (1)/(6) goes into viscous dissipation and (5)/(6) into Joule heating. The analytical results, based on the constant-psi approximation, are in good agreement with numerical simulations when the resistive layer is sufficiently narrow.

  10. 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

  11. 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.

  12. 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.

  13. Energy and mass balance calculations for incinerators

    SciTech Connect

    Lee, C.C.; Huffman, G.L.

    1998-01-01

    Calculation of energy and mass balance within an incinerator is a very important part of designing and/or evaluating the incineration process. This article describes a simple computer model used to calculate an energy and mass balance for a rotary kiln incinerator. The main purpose of the model is to assist US Environmental Protection Agency (EPA) permit writers in evaluating the adequacy of the data submitted by applicants seeking incinerator permits. The calculation is based on the assumption that a thermodynamic equilibrium condition exits within the combustion chamber. Key parameters that the model can calculate include theoretical combustion air, excess air needed for actual combustion cases, flue gas flow rate, and exit temperature.

  14. Energy-balanced algorithm for RFID estimation

    NASA Astrophysics Data System (ADS)

    Zhao, Jumin; Wang, Fangyuan; Li, Dengao; Yan, Lijuan

    2016-10-01

    RFID has been widely used in various commercial applications, ranging from inventory control, supply chain management to object tracking. It is necessary for us to estimate the number of RFID tags deployed in a large area periodically and automatically. Most of the prior works use passive tags to estimate and focus on designing time-efficient algorithms that can estimate tens of thousands of tags in seconds. But for a RFID reader to access tags in a large area, active tags are likely to be used due to their longer operational ranges. But these tags use their own battery as energy supplier. Hence, conserving energy for active tags becomes critical. Some prior works have studied how to reduce energy expenditure of a RFID reader when it reads tags IDs. In this paper, we study how to reduce the amount of energy consumed by active tags during the process of estimating the number of tags in a system and make the energy every tag consumed balanced approximately. We design energy-balanced estimation algorithm that can achieve our goal we mentioned above.

  15. 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

  16. 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

  17. Gut microbiota, nutrient sensing and energy balance.

    PubMed

    Duca, F A; Lam, T K T

    2014-09-01

    The gastrointestinal (GI) tract is a highly specialized sensory organ that provides crucial negative feedback during a meal, partly via a gut-brain axis. More specifically, enteroendocrine cells located throughout the GI tract are able to sense and respond to specific nutrients, releasing gut peptides that act in a paracrine, autocrine or endocrine fashion to regulate energy balance, thus controlling both food intake and possibly energy expenditure. Furthermore, the gut microbiota has been shown to provide a substantial metabolic and physiological contribution to the host, and metabolic disease such as obesity has been associated with aberrant gut microbiota and microbiome. Interestingly, recent evidence suggests that the gut microbiota can impact the gut-brain axis controlling energy balance, at both the level of intestinal nutrient-sensing mechanisms, as well as potentially at the sites of integration in the central nervous system. A better understanding of the intricate relationship between the gut microbiota and host energy-regulating pathways is crucial for uncovering the mechanisms responsible for the development of metabolic diseases and for possible therapeutic strategies.

  18. 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…

  19. Energy balance during recovery from malnutrition.

    PubMed

    Spady, D W; Payne, P R; Picou, D; Waterlow, J C

    1976-10-01

    This report presents an account of energy balance of young Jamaican children recovering from protein-energy malnutrition (PEM). This was done in three steps. Initially the true gross energy of a formula used in the treatment of PEM was determined by bomb calorimetry. Then its metabolizable energy content was determined in a group of nine children recovering from PEM. In a similar but different group of eight children total daily metabolizable energy intake (EI), average rate of weight gain (g/kg/day) (WG), and total daily energy expenditure (TDEE) were determined. TDEE was determined by indirect calorimetry using a heart rate counter and is based on the relationship of heart rate to oxygen consumption. In this group, the mean EI was 122.5 kcal, WG was 8.4 g, and TDEE was 92 kcal. The difference between EI and TDEE was 30.7 kcal/kg, or 3.3 kcal/g of weight gain. This difference is presumed to be the stored energy in new tissue and corresponds to a proposed new tissue composition of 31% fat and 14% protein. A regression curve comparison of WG versus EI showed that at zero weight gain EI was 85.5 kcal and each additional gain. The difference of 1.0 kcal between total energy cost and stored energy reflects the energy required to deposit new tissue. Gram weight gain required 4.4 kcal. The latter figure is felt to reflect the total energy cost of weight. From three independent measurements, an estimate of maintenance energy requirements was estimated to be about 82 kcal/kg/day.

  20. 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.

  1. Effects of sleep fragmentation on appetite and related hormone concentrations over 24 h in healthy men.

    PubMed

    Gonnissen, Hanne K J; Hursel, Rick; Rutters, Femke; Martens, Eveline A P; Westerterp-Plantenga, Margriet S

    2013-02-28

    In addition to short sleep duration, reduced sleep quality is also associated with appetite control. The present study examined the effect of sleep fragmentation, independent of sleep duration, on appetite profiles and 24 h profiles of hormones involved in energy balance regulation. A total of twelve healthy male subjects (age 23 (sd 4) years, BMI 24·4 (sd 1·9) kg/m²) completed a 24 h randomised crossover study in which sleep (23.30-07.30 hours) was either fragmented or non-fragmented. Polysomnography was used to determine rapid-eye movement (REM) sleep, slow-wave sleep (SWS) and total sleep time (TST). Blood samples were taken at baseline and continued hourly for the 24 h period to measure glucose, insulin, ghrelin, leptin, glucagon-like peptide 1 (GLP-1) and melatonin concentrations. In addition, salivary cortisol levels were measured. Visual analogue scales were used to score appetite-related feelings. Sleep fragmentation resulted in reduced REM sleep (69·4 min compared with 83·5 min; P< 0·05) and preservation of SWS without changes in TST. In fragmented v. non-fragmented sleep, glucose concentrations did not change, while insulin secretion was decreased in the morning, and increased in the afternoon (P< 0·05), and GLP-1 concentrations and fullness scores were lower (P< 0·05). After dinner, desire-to-eat ratings were higher after fragmented sleep (P< 0·05). A single night of fragmented sleep, resulting in reduced REM sleep, induced a shift in insulin concentrations, from being lower in the morning and higher in the afternoon, while GLP-1 concentrations and fullness scores were decreased. These results may lead to increased food intake and snacking, thus contributing to a positive energy balance.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Sleep patterns, diet quality and energy balance.

    PubMed

    Chaput, Jean-Philippe

    2014-07-01

    There is increasing evidence showing that sleep has an influence on eating behaviors. Short sleep duration, poor sleep quality, and later bedtimes are all associated with increased food intake, poor diet quality, and excess body weight. Insufficient sleep seems to facilitate the ingestion of calories when exposed to the modern obesogenic environment of readily accessible food. Lack of sleep has been shown to increase snacking, the number of meals consumed per day, and the preference for energy-rich foods. Proposed mechanisms by which insufficient sleep may increase caloric consumption include: (1) more time and opportunities for eating, (2) psychological distress, (3) greater sensitivity to food reward, (4) disinhibited eating, (5) more energy needed to sustain extended wakefulness, and (6) changes in appetite hormones. Globally, excess energy intake associated with not getting adequate sleep seems to be preferentially driven by hedonic rather than homeostatic factors. Moreover, the consumption of certain types of foods which impact the availability of tryptophan as well as the synthesis of serotonin and melatonin may aid in promoting sleep. In summary, multiple connections exist between sleep patterns, eating behavior and energy balance. Sleep should not be overlooked in obesity research and should be included as part of the lifestyle package that traditionally has focused on diet and physical activity.

  7. 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.

  8. Appetite and energy balance signals from adipocytes

    PubMed Central

    Trayhurn, Paul; Bing, Chen

    2006-01-01

    Interest in the biology of white adipose tissue has risen markedly with the recent surge in obesity and its associated disorders. The tissue is no longer viewed simply as a vehicle for lipid storage; instead, it is recognized as a major endocrine and secretory organ. White adipocytes release a multiplicity of protein hormones, signals and factors, termed adipokines, with an extensive range of physiological actions. Foremost among these various adipokines is the cytokine-like hormone, leptin, which is synthesized predominantly in white fat. Leptin plays a critical role in the control of appetite and energy balance, with mutations in the genes encoding the hormone or its receptor leading to profound obesity in both rodents and man. Leptin regulates appetite primarily through an interaction with hypothalamic neuroendocrine pathways, inhibiting orexigenic peptides such as neuropeptide Y and orexin A, and stimulating anorexigenic peptides such as proopiomelanocortin. White fat also secretes several putative appetite-related adipokines, which include interleukin-6 and adiponectin, but whether these are indeed significant signals in the regulation of food intake has not been established. Through leptin and the other adipokines it is evident that adipose tissue communicates extensively with other organs and plays a pervasive role in metabolic homeostasis. PMID:16815801

  9. 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.

  10. The ANIBES Study on Energy Balance in Spain: design, protocol and methodology.

    PubMed

    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

    2015-02-04

    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.

  11. The brain endocannabinoid system in the regulation of energy balance.

    PubMed

    Richard, Denis; Guesdon, Benjamin; Timofeeva, Elena

    2009-02-01

    The role played by the endocannabinoid system in the regulation of energy balance is currently generating a great amount of interest among several groups of investigators. This interest in large part comes from the urgent need to develop anti-obesity and anti-cachexia drugs around target systems (such as the endocannabinoid system), which appears to be genuinely involved in energy balance regulation. When activated, the endocannabinoid system favors energy deposition through increasing energy intake and reducing energy expenditure. This system is activated in obesity and following food deprivation, which further supports its authentic function in energy balance regulation. The cannabinoid receptor type 1 (CB1), one of the two identified cannabinoid receptors, is expressed in energy-balance brain structures that are also able to readily produce or inactivate N-arachidonoyl ethanolamine (anandamide) and 2-arachidonoylglycerol (2AG), the most abundantly formed and released endocannabinoids. The brain action of endocannabinoid system on energy balance seems crucial and needs to be delineated in the context of the homeostatic and hedonic controls of food intake and energy expenditure. These controls require the coordinated interaction of the hypothalamus, brainstem and limbic system and it appears imperative to unravel those interplays. It is also critical to investigate the metabolic endocannabinoid system while considering the panoply of functions that the endocannabinoid system fulfills in the brain and other tissues. This article aims at reviewing the potential mechanisms whereby the brain endocannabinoid system influences the regulation energy balance.

  12. Hindbrain DPP-IV inhibition improves glycemic control and promotes negative energy balance.

    PubMed

    Mietlicki-Baase, Elizabeth G; McGrath, Lauren E; Koch-Laskowski, Kieran; Krawczyk, Joanna; Pham, Tram; Lhamo, Rinzin; Reiner, David J; Hayes, Matthew R

    2017-05-01

    The beneficial glycemic and food intake-suppressive effects of glucagon-like peptide-1 (GLP-1) have made this neuroendocrine system a leading target for pharmacological approaches to the treatment of diabetes and obesity. One strategy to increase the activity of endogenous GLP-1 is to prevent the rapid degradation of the hormone by the enzyme dipeptidyl peptidase-IV (DPP-IV). However, despite the expression of both DPP-IV and GLP-1 in the brain, and the clear importance of central GLP-1 receptor (GLP-1R) signaling for glycemic and energy balance control, the metabolic effects of central inhibition of DPP-IV activity are unclear. To test whether hindbrain DPP-IV inhibition suppresses blood glucose, feeding, and body weight gain, the effects of 4th intracerebroventricular (ICV) administration of the FDA-approved DPP-IV inhibitor sitagliptin were evaluated. Results indicate that hindbrain delivery of sitagliptin improves glycemic control in a GLP-1R-dependent manner, suggesting that this effect is due at least in part to increased endogenous brainstem GLP-1 activity after sitagliptin administration. Furthermore, 4th ICV injection of sitagliptin reduced 24h body weight gain and energy intake, with a selective suppression of high-fat diet, but not chow, intake. These data reveal a novel role for hindbrain GLP-1R activation in glycemic control and also demonstrate that DPP-IV inhibition in the caudal brainstem promotes negative energy balance.

  13. 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

  14. 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

  15. 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

    2016-06-09

    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.

  16. Fuel feeds function: Energy balance and bovine peripheral blood mononuclear cell activation.

    PubMed

    Schwarm, A; Viergutz, T; Kuhla, B; Hammon, H M; Schweigel-Röntgen, M

    2013-01-01

    A general phenomenon in peripartum mammals is the breakdown of (acquired) immunity. The incidence of parasite load, disease and inflammation often rise during the specific energetically demanding time of pregnancy and lactation. In this period, blood leukocytes display decreased DNA synthesis in response to mitogens in vitro. Leukocyte activation, the phase of the cell cycle preceding the DNA synthetic phase has hardly been investigated, but the few studies suggest that leukocyte activation may also be impaired by the limited energy/nutrient availability. Leukocyte activation is characterized by manifold processes, thus, we used the cellular oxygen consumption rate (OCR) as a measure of ATP turnover to support all these processes. We hypothesized that the activation of peripheral blood mononuclear cells (PBMC) - in terms of oxygen consumed over basal levels after in vitro stimulation - is altered by energy balance around parturition. We studied peripartum high-yielding dairy cows because they undergo substantial fluctuations in energy intake, energy output and body fat mass. We established a fluorescence-based test strategy allowing for long-term (≥24h) quantification of O(2)-consumption and studied the peripartum period from 5 weeks ante partum to 5 weeks postpartum. In addition, we determined cellular lactate production, DNA/RNA synthesis and cell size and zoo-technical parameters such as animal energy intake and milk yield were assessed, as well as selected plasma parameters, e.g. glucose concentration. The basal OCR of PBMC from pregnant, non-lactating cows (n=6, -5 weeks ante partum) was 1.19±0.15 nmol min(-1) (10(7)cells)(-1) and increased to maximum levels of 2.54±0.49 nmol min(-1) (10(7)cells)(-1) in phytohemagglutinin (PHA)-stimulated PBMC. The basal OCR did not change over the peripartum period. Whereas the activation indices, herein defined as the PHA-induced 24h-increase of OCR above baseline, amounted to 1.1±0.3, 4.2±0.3, 4.1±1.1, 2.1±0.3, and

  17. 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)

  18. Melanocortin control of energy balance: evidence from rodent models.

    PubMed

    De Jonghe, Bart C; Hayes, Matthew R; Bence, Kendra K

    2011-08-01

    Regulation of energy balance is extremely complex, and involves multiple systems of hormones, neurotransmitters, receptors, and intracellular signals. As data have accumulated over the last two decades, the CNS melanocortin system is now identified as a prominent integrative network of energy balance controls in the mammalian brain. Here, we will review findings from rat and mouse models, which have provided an important framework in which to study melanocortin function. Perhaps most importantly, this review attempts for the first time to summarize recent advances in our understanding of the intracellular signaling pathways thought to mediate the action of melanocortin neurons and peptides in control of longterm energy balance. Special attention will be paid to the roles of MC4R/MC3R, as well as downstream neurotransmitters within forebrain and hindbrain structures that illustrate the distributed control of melanocortin signaling in energy balance. In addition, distinctions and controversy between rodent species will be discussed.

  19. Hypothalamic proopiomelanocortin processing and the regulation of energy balance

    PubMed Central

    Wardlaw, Sharon L.

    2011-01-01

    Hypothalamic proopiomelanocortin (POMC) neurons play a key role in regulating energy balance and neuroendocrine function. Much attention has been focused on regulation of POMC gene expression with less emphasis on regulated peptide processing. This is particularly important given the complexity of posttranslational POMC processing which is essential for the generation of biologically active MSH peptides. Mutations that impair POMC sorting and processing are associated with obesity in humans and in animals. Specifically, mutations in the POMC processing enzymes prohormone convertase 1/3 (PCI/3) and in carboxypeptidase E (CPE) and in the α-MSH degrading enzyme, PRCP, are associated with changes in energy balance. There is increasing evidence that POMC processing is regulated with respect to energy balance. Studies have implicated both the leptin and insulin signaling pathways in the regulation of POMC at various steps in the processing pathway. This article will review the role of hypothalamic POMC in regulating energy balance with a focus on POMC processing. PMID:21208604

  20. 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.

  1. 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

  2. Suburban Energy Balance Estimates for Vancouver, B.C., Using the Bowen Ratio-Energy Balance Approach.

    NASA Astrophysics Data System (ADS)

    Kalanda, B. D.; Oke, T. R.; Spittlehouse, D. L.

    1980-07-01

    The energy balance of a suburban site in Vancouver, B.C. in late summer is presented. The balance is obtained from direct measurements of net radiation, parameterized heat storage and turbulent fluxes determined according to the Bowen ratio-energy balance method with reversing psychrometers. An error analysis shows the turbulent fluxes are good to within 10-20% by day. Features of the suburban energy balance are found to be intermediate between those previously reported for urban and rural surfaces. Average daytime Bowen ratios are usually in the range 0.5-1.0 with some days as high as 2.5. The daytime sensible heat flux is in-phase with the net radiation. At night this flux is sometimes positive. Evapotranspiration is always an important term in the balance. The role of urban irrigation and microscale heat advection in maintaining evapotranspiration rates is discussed.

  3. 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…

  4. Analysis of surface energy balance closure over heterogeneous surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Soojin; Lee, Young-Hee; Kim, Kyu Rang; Park, Young-San

    2014-11-01

    Surface energy balance closure has been examined using eddy covariance measurements and other observations at one industrial and three agricultural sites near the Nakdong River during daytime. Energy balance closure was evaluated by calculating the long-term averaged energy balance ratio (EBR), the ratio of turbulent energy fluxes to available energy, and the statistical regression of turbulent energy fluxes against available energy using half-hourly data. The EBR of all sites ranges from 0.46 to 0.83 while the coefficient of determination ( R 2) ranges from 0.37 to 0.77. The energy balance closure was relatively poor compared to homogeneous sites, indicating the influence of surface heterogeneity. Unmeasured heat storage terms also seem to play a role in the surface energy budget at the industrial and irrigated sites. The energy balance closure was better in conditions of high wind speed, low downward short wave radiation, and high friction velocity, which suggests the role of heat storage term and surface heterogeneity in surface energy balance at these sites. Spectrum analysis shows a sharp roll-off at the low frequency in co-spectrum, which indicates that low-frequency motions do not significantly contribute to turbulent fluxes. Both the spectra and cospectra in unstable conditions show a broad peak indicating the influence of multiple sizes of large eddies over heterogeneous sites. Most of ogive curves for the kinematic latent and sensible heat fluxes reach an asymptote within 30 minutes regardless of the EBR value, indicating that low frequency motion is not a main factor for energy imbalance. However, stationary eddies due to landscape heterogeneity still remains as a possible cause for energy imbalance.

  5. 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

  6. 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

  7. Balancing the energy equation for healthy kidneys.

    PubMed

    Mount, Peter F; Power, David A

    2015-12-01

    The high-energy requirement of the kidney and the importance of energy metabolism in renal physiology has been appreciated for decades, but only recently has there emerged a strong link between impaired renal energy metabolism and chronic kidney disease (CKD). The mechanisms underlying the association between changes in energy metabolism and progression of CKD, however, remain poorly understood. A new study from Qiu and colleagues reported in the Journal of Pathology has advanced this understanding by showing that, after renal injury, the energy sensor AMPK inhibits epithelial-mesenchymal transition and inflammation, processes important in the pathogenesis of CKD. Furthermore, this study identifies an interaction between AMPK and CK2β as an important mechanism in the anti-fibrotic effect. CK2β has previously been shown to interact with STK11 (also known as LKB1) to regulate cellular polarity. These findings are consistent with the known roles of the LKB1-AMPK pathway in sustaining cellular energy homeostasis and epithelial cell polarity, and add to growing evidence linking the suppression of energy metabolism to CKD. They emphasize the importance of energy metabolism in general and the LKB1-AMPK axis in particular as key investigational and therapeutic targets in the battle against CKD.

  8. 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%.

  9. 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

  10. 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.

  11. 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...

  12. Ground Energy Balance For Shallow Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Bayer, P.; Rivera, J.

    2015-12-01

    Vertical borehole heat exchangers (BHE) represent the most common applications by far in the field of shallow geothermal energy. They are typically operated for decades for energy extraction from the top 400 m of the subsurface. During this lifetime, thermal anomalies are generated in the ground and surface-near aquifers. These anomalies often grow over the years and compromise the overall performance of the geothermal system. As a basis for prediction and control of the developing energy imbalance in the ground, the focus is often set on the ground temperatures. This is reflected, for instance, in regulative temperature thresholds. As an alternative to temperature, we examine the temporal and spatial variability of heat fluxes and power sources during geothermal heat pump operation. The underlying idea is that knowledge of the primary heat sources is fundamental for the control of ground temperature evolution. For analysis of heat fluxes, an analytical framework for BHE simulation based on Kelvin's line source is re-formulated. This is applied to a synthetic study and for modelling a long-term application in the field. Our results show that during early operation phase, energy is extracted mainly from the underground. Local depletion at the borehole enhances the vertical fluxes with the relative contribution from the bottom reaching a limit of 24 % of the total power demand. The relative contribution from the ground surface becomes dominant for Fourier numbers larger than 0.13. For the full life cycle, vertical heat flux from the ground surface dominates the basal heat flux towards the BHE and it provides about two thirds of the demanded power. Finally, we reveal that the time for ground energy recovery after BHE shutdown may be longer than what is expected from simulated temperature trends.

  13. Serum immunoreactive relaxin in women during a 24-h period.

    PubMed

    Seki, K; Kato, K; Tabei, T

    1987-03-01

    Serum relaxin concentrations were measured every 30 min during a 24-h period in nonpregnant and pregnant women. Relaxin was undetectable in all serum samples obtained from 3 nonpregnant women. Relaxin was detectable in all serum samples obtained from 2 pregnant women. However, neither episodic secretion of relaxin nor a 24-h rhythm in relaxin secretion was discernible in these women.

  14. 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.

  15. 24-h hydration status: parameters, epidemiology and recommendations.

    PubMed

    Manz, F; Wentz, A

    2003-12-01

    Hydration of individuals and groups is characterised by comparing actual urine osmolality (Uosm) with maximum Uosm. Data of actual, maximum and minimum Uosm in infants, children and adults and its major influencing factors are reviewed. There are remarkable ontogenetic, individual and cultural differences in Uosm. In the foetus and the breast-fed infant Uosm is much lower than plasma osmolality, whereas in children and adults it is usually much higher. Individuals and groups may show long-term differences in Uosm. In industrialised countries, the gender difference of Uosm is common. There are large intercultural differences of mean 24-h Uosm ranging from 860 mosm/kg in Germany, 649 mosm/kg in USA to 392 mosm/kg in Poland. A new physiologically based concept called 'free-water reserve' quantifies differences in 24-h euhydration. In 189 boys of the DONALD Study aged 4.0-6.9 y, median urine volume was 497 ml/24-h and median Uosm 809 mosm/kg. Considering mean-2 s.d. of actual maximum 24-h Uosm of 830 mosm/kg as upper level of euhydration and physiological criterion of adequate hydration in these boys, median free-water reserve was 11 ml/24-h. Based on median total water intake of 1310 ml/24-h and the third percentile of free-water volume of -156 ml/24-h, adequate total water intake was 1466 ml/24-h or 1.01 ml/kcal. Data of Uosm in 24-h urine samples and corresponding free-water reserve values of homogeneous groups of healthy subjects from all over the world might be useful parameters in epidemiology to investigate the health effects of different levels of 24-h euhydration.

  16. 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.

  17. Surface energy balance calculations for small northern lakes

    NASA Astrophysics Data System (ADS)

    Binyamin, J.; Rouse, W. R.; Davies, J. A.; Oswald, C. J.; Schertzer, W. M.

    2006-12-01

    An energy balance model is used to determine diurnal surface energy balance components for three different sized high-latitude Canadian lakes in the Mackenzie River Basin (MRB) during the open water seasons of 2000, 2001, and 2002. Surface net radiation is derived from the component fluxes of the radiation balance. Turbulent heat fluxes are calculated using the aerodynamic method with input from local meteorological stations and experimentally derived drag coefficients. Lake heat storage, determined as a residual of the surface energy balance, is used together with measured water temperature profiles to calculate the daily mixing layer depth. The model uses readily available meteorological inputs for radiation calculations.Verification results for surface energy balance components show mean bias error (MBE) generally less than 5% of the mean measured daily fluxes and root mean square error (RMSE) less than 38%, which decreases to less than 16% for 10-day averaging periods. The model tends to overestimate net radiation by 7% and latent and sensible heat fluxes by about 4% and 1%, respectively, on average. Inferred slab layer depths indicate that the shallowest lake was isothermal while the deeper lakes showed temporal variations as expected.

  18. Meteorology Of The Clark Atlanta University Local Energy Balance Module

    NASA Astrophysics Data System (ADS)

    Mandock, R. L.; Mills, I.; Paxton, J. N.

    2005-05-01

    The Earth System Science Program (ESSP) at Clark Atlanta University has developed an instructional module to study energy balance at the air/land and air/sea interfaces. A graphical user interface (GUI) has been developed which is used to model each of the components (net radiation, sensible and latent heat fluxes, ground heat flux, storage, anthropomorphic, and residual) necessary to understand the partitioning of energy at the air/land and air/water interfaces. The energy balance diagram consists of sky elements (sun, moon, clouds), a line representing the air/land or water/land interface, and arrows which indicate magnitude and direction of each of the energy fluxes. The storage component is represented as a box when present. The energy balance model has been applied to numerous (33 at present) scenarios which vary by (1) climate or microclimate, (2) day and night, (2) cloudiness and sunshine, (3) windy and calm, (4) land or water surface, and (5) freezing and non-freezing temperatures. The model is available in 2 levels of rigor: (1) an elementary level (Level I), and (2) and advanced level (Level II). In the Level I model only fixed arrow lengths (e.g., zero, 1/4, 1/2, 3/4, 1) are available to express flux magnitude. This allows a qualitative illustration of the energy balance components. The Level II model requires the student to calculate arrow magnitudes and directions from diffusion, evaporation, radiative transfer, and energy storage equations. The module incorporates not only the energy balance model, but also a protocol by which meteorological observations from the ESSP's rooftop laboratory, the AEMN (Georgia Automated Environmental Monitoring Network), and other online resources. The completed module is designed to serve two audiences: (1) undergraduate introductory science classes and grades 8-12, and (2) upper-division science and engineering classes.

  19. 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.

  20. Dcf1 regulates neuropeptide expression and maintains energy balance.

    PubMed

    Liu, Qiang; Chen, Yu; Li, Qian; Wu, Liang; Wen, Tieqiao

    2017-04-01

    Neuropeptide Y (NPY) is an important neurotransmitter in the brain that plays a pivotal role in food intake and energy storage. Although many studies have focused on these functions, the regulation of NPY expression remains unclear. Here we showed that dendritic cell factor 1 (Dcf1) regulates NPY expression and maintains energy balance. We found that NPY expression is significantly reduced in the hypothalamus of Dcf1 knockout (Dcf1(-/-), KO) mice. In contrast, Dcf1 overexpression significantly increases NPY expression in the cell line. We also found that Dcf1 acts upstream of the NPY gene to regulate NPY expression and modulates the NPY-NPY receptor 1-GABA signal. Notably, we observed a significant increase in the ATP concentration in Dcf1(-/-) mice, suggesting a greater demand for energy in the absence of Dcf1. We studied the relationship between Dcf1 and NPY and revealed that Dcf1 plays a critical role in energy balance.

  1. The energy balance of the solar transition region

    NASA Technical Reports Server (NTRS)

    Jordan, C.

    1980-01-01

    It is shown how the observed distribution of the emission measure with temperature can be used to limit the range of energy deposition functions suitable for heating the solar transition region and inner corona. The minimum energy loss solution is considered in view of the work by Hearn (1975) in order to establish further scaling laws between the transition region pressure, the maximum coronal temperature and the parameter giving the absolute value of the emission measure. Also discussed is the absence of a static energy balance at the base of the transition region in terms of measurable atmospheric parameters, and the condition for a static energy balance is given. In addition, the possible role of the emission from He II in stabilizing the atmosphere by providing enhanced radiation loss is considered.

  2. 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…

  3. 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.

  4. 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.

  5. 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...

  6. Mineral balance in milk heated using microwave energy.

    PubMed

    de la Fuente, Miguel Angel; Olano, Agustín; Juárez, Manuela

    2002-04-10

    Milk heated to 75 and 85 degrees C in a water bath or in a microwave oven was assayed for changes in salt partitioning after cooling to room temperature. To properly to assess differences and draw valid comparisons, the two heating methods used in the experiment were applied to samples for identical exposure times, and the samples were heated to attain the same final temperatures. Although the soluble Ca and P(i) contents were lower in the heated milk samples, no significant differences in salt partitioning were found between microwave and conventional heating. Ionic calcium levels in the milk samples pasteurized using microwave energy were very close to the levels in the samples heated in a conventional water bath (approximately 90% of the level in the untreated milk samples). The microwave heating-induced changes were completely reversed after storage at 20 degrees C for 24 h. The coagulation properties of the heated milk samples were also examined, and the coagulation time was longer and the curd formation rate slower in the microwave-heated milk than in the raw milk. Still, the experimental results demonstrated that microwave heating was no more detrimental to the milk than conventional heating and could thus be used for pasteurization purposes.

  7. 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

  8. 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

  9. Report Calls for Balancing Energy Security, Energy Equity, and Environmental Concerns

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2014-12-01

    Balancing the sometimes conflicting needs for energy security, energy equity, and environmental sustainability—including trying to limit average global temperature increases—can be a daunting task for countries. A new report focuses on the challenges and potential pathways to achieving this energy "trilemma" of meeting energy and environmental needs.

  10. Prediction of energy balance in high yielding dairy cows with test-day information.

    PubMed

    Heuer, C; Van Straalen, W M; Schukken, Y H; Dirkzwager, A; Noordhuizen, T M

    2001-02-01

    This study used a previously developed model to predict herd mean energy balance of the first 12 wk of lactation from test-day information. The predictions were compared with calculated energy balance based on feed analysis and to changes in body weight. Seven independent feeding trials including 43 diets (519 lactations, 254 cows; 1987 to 1996) were used. Conventional diets were discriminated from nonconventional diets by significant differences between mean calculated energy balance of subtrial diets versus control diets. The total difference between group means of predicted minus calculated energy balance was positive throughout the observed lactation period. It was lowest (5 to 9 MJ of net energy for lactation) during negative energy balance of the conventional diets in wk 2 to 7 when 18 to 50% of the total difference was due to random variation. Because of this difference, both predicted and calculated energy balances were compared to body weight change as a reference for true energy balance. Body weight change was adjusted for rumen fill. While calculated energy balance tended to be negative at times when cows gained weight, predicted energy balance was positive. Cows fed nonconventional diets gained weight, while calculated energy balance was extremely negative, whereas predicted energy balance based on test-day information was positive. We concluded that the prediction difference was relatively small when standard rations were used, and that nonconventional rations biased predicted energy balance to a lesser extent than calculated energy balance. Estimating energy balance based on test-day information appears feasible.

  11. 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

  12. 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).

  13. Daily energy balance in children and adolescents. Does energy expenditure predict subsequent energy intake?

    PubMed

    Thivel, David; Aucouturier, Julien; Doucet, Éric; Saunders, Travis J; Chaput, Jean-Philippe

    2013-01-01

    Both physical and sedentary activities primarily impact energy balance through energy expenditure, but they also have important implications in term of ingestive behavior. The literature provides scarce evidence on the relationship between daily activities and subsequent nutritional adaptations in children and adolescents. Sedentary activities and physical exercise are generally considered distinctly despite the fact that they represent the whole continuum of daily activity-induced energy expenditure. This brief review paper examines the impact of daily activities (from vigorous physical activity to imposed sedentary behaviors) on acute energy intake control of lean and obese children and adolescents, and whether energy expenditure is the main predictor of subsequent energy intake in this population. After an overview of the available literature, we conclude that both acute physical activity and sedentary behaviors induce food consumption modifications in children and adolescents but also that the important discrepancy between the methodologies used does not allow any clear conclusion so far. When considering energy intake responses according to the level of energy expenditure generated by those activities, it is clear that energy expenditure is not the main predictor of food consumption in both lean and obese children and adolescents. This suggests that other characteristics of those activities may have a greater impact on calorie intake (such as intensity, duration or induced mental stress) and that energy intake may be mainly determined by non-homeostatic pathways that could override the energetic and hormonal signals.

  14. Energy intake, physical activity, energy balance, and cancer: epidemiologic evidence.

    PubMed

    Pan, Sai Yi; DesMeules, Marie

    2009-01-01

    Energy intake, physical activity, and obesity are modifiable lifestyle factors. This chapter reviews and summarizes the epidemiologic evidence on the relation of energy intake, physical activity, and obesity to cancer. High energy intake may increase the risk of cancers of colon-rectum, prostate (especially advanced prostate cancer), and breast. However, because physical activity, body size, and metabolic efficiency are highly related to total energy intake and expenditure, it is difficult to assess the independent effect of energy intake on cancer risk. There are sufficient evidences to support a role of physical activity in preventing cancers of the colon and breast, whereas the association is stronger in men than in women for colon cancer and in postmenopausal than in premenopausal women for breast cancer. The evidence also suggests that physical activity likely reduces the risk of cancers of endometrium, lung, and prostate (to a lesser extent). On the other hand, there is little or no evidence that the risk of rectal cancer is related to physical activity, whereas the results have been inconsistent regarding the association between physical activity and the risks of cancers of pancreas, ovary and kidney. Epidemiologic studies provide sufficient evidence that obesity is a risk factor for both cancer incidence and mortality. The evidence supports strong links of obesity with the risk of cancers of the colon, rectum, breast (in postmenopausal women), endometrium, kidney (renal cell), and adenocarcinoma of the esophagus. Epidemiologic evidence also indicates that obesity is probably related to cancers of the pancreas, liver, and gallbladder, and aggressive prostate cancer, while it seems that obesity is not associated with lung cancer. The role of obesity in other cancer risks is unclear.

  15. 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.

  16. Energy and mass balances related to climate change and remediation.

    PubMed

    Lueking, Angela D; Cole, Milton W

    2017-07-15

    The goal of this paper is to provide a forum for a broad interdisciplinary group of scientists and engineers to see how concepts of climate change, energy, and carbon remediation strategies are related to quite basic scientific principles. A secondary goal is to show relationships between general concepts in traditional science and engineering fields and to show how they are relevant to broader environmental concepts. This paper revisits Fourier's early mathematical derivation of the average temperature of the Earth from first principles, i.e. an energy balance common to chemical and environmental engineering. The work then uses the concept of mass balance to critically discuss various carbon remediation strategies. The work is of interest to traditional scientists/engineers, but also it is potentially useful as an educational document in advanced undergraduate science or engineering classes.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Energy balance regulation by thyroid hormones at central level.

    PubMed

    López, Miguel; Alvarez, Clara V; Nogueiras, Rubén; Diéguez, Carlos

    2013-07-01

    Classically, medical textbooks taught that most effects of thyroid hormones (THs) on energy homeostasis are directly exerted in peripheral tissues. However, current evidence is changing (and challenging) our perspective about the role of THs from a 'peripheral' to a 'central' vision, implying that they affect food intake, energy expenditure, and metabolism by acting, to a large extent, at the central level. Interestingly, effects of THs are interrelated with global energy sensors in the central nervous system (CNS), such as uncoupling protein 2 (UCP2), AMP-activated protein kinase (AMPK; the 'AMPK-BAT axis'), and mechanistic target of rapamycin (mTOR). Here, we review what is currently known about THs and their regulation of energy balance and metabolism in both peripheral and central tissues.

  2. Balance or bias: building an equitable energy budget

    SciTech Connect

    DeVaul, D.

    1982-01-01

    The findings of two major studies on the effects of high energy prices are summarized in an effort to develop reliable data for purposes of explanation. The first study, Regional Energy, reviews what is known about the relationship between energy price increases and national economic performance in the 1970s, and details the regional, state, and local effects. The second study, The Impact of Federal Energy Policies, analyzes the effect of federal policies and programs since World War II on the price and availability of energy in different sections of the country. An analysis of past energy policies reveals a strong bias toward oil- and gas-producing areas that is out of balance with national energy needs in the 1980s. Current federal policies continue those biases to the detriment of energy-dependent areas, particularly those in the Northeast and Midwest. The monograph concludes with a series of policy options designed to correct the imbalance in the federal energy budget. 2 figures, 5 tables.

  3. 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

  4. Earth's Energy Balance From Space: A 35 Year Perspective

    NASA Astrophysics Data System (ADS)

    Wielicki, B. A.

    2005-12-01

    The Earth's radiative energy balance is the most fundamental driver of long term climate. Changes of 1% or less are sufficient to cause major climate change. Earth orbiting satellites provide the optimal platform to observe this energy balance, and efforts began with Nimbus 3 in 1969. Prior to satellite missions, the Earths reflected and emitted radiation were estimated using earthshine from the moon, or by a radiative transfer calculation using surface observations of aerosol, cloud, temperature, humidity, and ozone. Observing the earths radiation balance from space is an 8-dimensional sampling problem, with a requirement for extremely high accuracy and stability to directly observe climate signals. The challenge is especially severe for decadal changes in aerosols and clouds. A perspective is given on the dramatic progress that has occurred in measuring radiation in space, from Nimbus 3 in 1969 to current CERES global and GERB geostationary observations. A vision for future advances in these observations as part of the global climate observing system is also given, including new ways to use the data in unscrambling the effects of aerosol indirect effects as well as cloud feedback in the climate system. These last two issues provide extraordinary challenges in climate forcing and climate sensitivity respectively.

  5. 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.

  6. Influence of topiramate in the regulation of energy balance.

    PubMed

    Richard, D; Ferland, J; Lalonde, J; Samson, P; Deshaies, Y

    2000-10-01

    Topiramate (TPM) is a novel neurotherapeutic agent currently indicated for the treatment of epilepsy and undergoing development for other central nervous system indications including neuropathic pain, bipolar disorder, and migraine prophylaxis. TPM is synthesized from D-fructose and contains a sulfamate moiety that is essential for its pharmacologic activity. TPM has been observed to significantly reduce body weight in patients treated for seizure, which has prompted the realization of preclinical studies to characterize the effects of TPM in the regulation of energy balance. Studies carried out in various strains of rats have provided good evidence for the ability of TPM to blunt energy deposition. Body composition analyses from rat trials have demonstrated that TPM inhibits fat deposition while reducing the activity of lipoprotein lipase (LPL) in various white adipose tissue depots. High doses of TPM (likely above the therapeutic dose range) have also been observed to reduce protein gain without catabolic effects. Although TPM cannot be described as a potent anorectic agent, it seems to have the ability to reduce food intake; significant reductions in food intake have been observed in female obese (fa/fa) Zucker rats and in female Wistar rats. TPM can also reduce energy deposition in the absence of alterations in food intake. This effect has been clearly emphasized in female lean (Fa/?) Zucker rats. In female Sprague-Dawley rats, TPM also increased energy expenditure and it has been observed to increase LPL activity in brown adipose tissue, which could indicate that TPM has the ability to enhance regulatory thermogenesis. In addition, TPM stimulates LPL activity in skeletal muscles, further emphasizing its potential to promote substrate oxidation. The mechanisms whereby TPM affects the regulation of energy balance have yet to be understood. TPM represents an antiepileptic drug (AED) with complex biochemical/pharmacologic actions. Its negative effects on energy

  7. Leptin: at the crossroads of energy balance and systemic inflammation

    PubMed Central

    Steiner, Alexandre A.; Romanovsky, Andrej A.

    2007-01-01

    In addition to playing a central role in energy homeostasis, leptin is also an important player in the inflammatory response. Systemic inflammation is accompanied by fever (less severe cases) or hypothermia (more severe cases). In leptin-irresponsive mutants, the hypothermia of systemic inflammation is exaggerated, presumably due to the enhanced production and cryogenic action of tumor necrosis factor (TNF)-α. Mechanisms that exaggerate hypothermia can also attenuate fever, particularly in a cool environment. Another common manifestation of systemic inflammation is behavioral depression. Along with the production of interleukin (IL)-1β, this manifestation is exaggerated in leptin-irresponsive mutants. The enhanced production of TNF-α and IL-1β may be due, at least in part, to insufficient activation of the anti-inflammatory hypothalamo-pituitary-adrenal axis by immune stimuli in the absence of leptin signaling. In experimental animals and humans that are responsive to leptin, suppression of leptin production under conditions of negative energy balance (e.g., fasting) can exaggerate both hypothermia and behavioral depression. Since these manifestations aid energy conservation, exaggeration of these manifestations under conditions of negative energy balance is likely to be beneficial. PMID:17275915

  8. [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.

  9. Alternative energy balances for Bulgaria to mitigate climate change

    SciTech Connect

    Christov, C.

    1996-09-01

    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 CO{sub 2} 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; waste-heat 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. 3 refs.

  10. 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.

  11. Brain regulation of energy balance and body weight.

    PubMed

    Rui, Liangyou

    2013-12-01

    Body weight is determined by a balance between food intake and energy expenditure. Multiple neural circuits in the brain have evolved to process information about food, food-related cues and food consumption to control feeding behavior. Numerous gastrointestinal endocrine cells produce and secrete satiety hormones in response to food consumption and digestion. These hormones suppress hunger and promote satiation and satiety mainly through hindbrain circuits, thus governing meal-by-meal eating behavior. In contrast, the hypothalamus integrates adiposity signals to regulate long-term energy balance and body weight. Distinct hypothalamic areas and various orexigenic and anorexigenic neurons have been identified to homeostatically regulate food intake. The hypothalamic circuits regulate food intake in part by modulating the sensitivity of the hindbrain to short-term satiety hormones. The hedonic and incentive properties of foods and food-related cues are processed by the corticolimbic reward circuits. The mesolimbic dopamine system encodes subjective "liking" and "wanting" of palatable foods, which is subjected to modulation by the hindbrain and the hypothalamic homeostatic circuits and by satiety and adiposity hormones. Satiety and adiposity hormones also promote energy expenditure by stimulating brown adipose tissue (BAT) activity. They stimulate BAT thermogenesis mainly by increasing the sympathetic outflow to BAT. Many defects in satiety and/or adiposity hormone signaling and in the hindbrain and the hypothalamic circuits have been described and are believed to contribute to the pathogenesis of energy imbalance and obesity.

  12. Energy balance for analysis of complex metabolic networks.

    PubMed Central

    Beard, Daniel A; Liang, Shou-dan; Qian, Hong

    2002-01-01

    Predicting behavior of large-scale biochemical networks represents one of the greatest challenges of bioinformatics and computational biology. Computational tools for predicting fluxes in biochemical networks are applied in the fields of integrated and systems biology, bioinformatics, and genomics, and to aid in drug discovery and identification of potential drug targets. 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 promising tools for the analysis of large complex networks. Here we introduce energy balance analysis (EBA)--the theory and methodology for enforcing the laws of thermodynamics in such simulations--making the results more physically realistic and revealing greater insight into the regulatory and control mechanisms operating in complex large-scale systems. We show that EBA eliminates thermodynamically infeasible results associated with FBA. PMID:12080101

  13. 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

  14. 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.

  15. 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

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

    PubMed

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

    2015-04-01

    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 24h post attachment to be transmitted. This study describes identification of 24h 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 24h fed female I. scapularis phage display cDNA expression library was biopanned using rabbit antibodies to 24h 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 24h, before the majority of TBD agents can be transmitted.

  17. 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

  18. Energy Balance of a Typical U.S. Diet

    PubMed Central

    Alexandrou, Athanasios; Tenbergen, Klaus; Adhikari, Diganta

    2013-01-01

    Today’s agriculture provides an ever increasing population with sufficient quantities of food. During food production, processing, handling and transportation, an amount of energy is invested into the various products. An energy analysis of a typical American diet provides policy makers, farmers and the public with the necessary information to evaluate and make informed decisions as to how to improve the efficient use of energy. At the same time, an informed consumer may become energy conscious and be able to make dietary choices based on food energy balance. This paper studies the energy sequestered in a typical American diet as defined in Food and Agriculture Organization of the United Nations, Statistics Division (FAOSTAT). The amount of energy incorporated in this diet of 3628 kcal (15.18 MJ) per person and day to produce, transport, handle and process the foods is calculated and found to have approximately 39.92 GJ (9.54 Gcal) sequestered per person and year. It is shown that a diet in line with the United States Department of Agriculture (USDA) recommendation of around 2100 kcal (8.79 MJ) per day person will result in a reduction of energy inputs by 42% on an annual basis. This reduction for the whole population of the United States of America (USA), corresponds to approximately 879 million barrels of oil equivalent (boe) savings. Energy efficiency for the food categories studied varies from 3.4% to 56.5% with an average of 21.7%. Food energy efficiency can be further improved in some food categories through either a reduction of energy inputs or yield increase.

  19. Energy Balance of a Typical U.S. Diet.

    PubMed

    Alexandrou, Athanasios; Tenbergen, Klaus; Adhikari, Diganta

    2013-03-28

    Today's agriculture provides an ever increasing population with sufficient quantities of food. During food production, processing, handling and transportation, an amount of energy is invested into the various products. An energy analysis of a typical American diet provides policy makers, farmers and the public with the necessary information to evaluate and make informed decisions as to how to improve the efficient use of energy. At the same time, an informed consumer may become energy conscious and be able to make dietary choices based on food energy balance. This paper studies the energy sequestered in a typical American diet as defined in Food and Agriculture Organization of the United Nations, Statistics Division (FAOSTAT). The amount of energy incorporated in this diet of 3628 kcal (15.18 MJ) per person and day to produce, transport, handle and process the foods is calculated and found to have approximately 39.92 GJ (9.54 Gcal) sequestered per person and year. It is shown that a diet in line with the United States Department of Agriculture (USDA) recommendation of around 2100 kcal (8.79 MJ) per day person will result in a reduction of energy inputs by 42% on an annual basis. This reduction for the whole population of the United States of America (USA), corresponds to approximately 879 million barrels of oil equivalent (boe) savings. Energy efficiency for the food categories studied varies from 3.4% to 56.5% with an average of 21.7%. Food energy efficiency can be further improved in some food categories through either a reduction of energy inputs or yield increase.

  20. Role of Northern Lakes in Landscape Energy Balance

    NASA Astrophysics Data System (ADS)

    Rouse, W. R.; Oswald, C. J.; Spence, C.; Blanken, P. D.; Bussières, N.; Schertzer, W. M.; Duguay, C. R.; Binyamin, J.

    2004-05-01

    In the central Mackenzie River Valley of western Canada, from which most of the data used in this study are derived, there are about 32,370 lakes. For the specific study region used to determine the landscape energy balance, lakes comprise 37% of the landscape. They are classified as small (<1 km2), medium (1-100 km2) and large (>100 km2). The large lake is represented by the central portion of Great Slave Lake. The non-lake components of the landscape are divided into wetlands (8%) and uplands (55%). With such abundance, lakes are important features in regional climatic, meteorological and biogeochemical cycling. The purpose of this paper is to examine the regional role of lakes in the surface energy and water balance, to link this to the frequency-size distribution of lakes, and to cast some light on how the surface energy balance may influence regional climate and weather processes. Toward this end we employ recently-gathered data from northern lakes of various sizes, characterize their surface energy balances for both magnitude and temporal behavior of fluxes, and examine the impacts of combinations of various-size lakes and land-lake distributions on regional energy balances and evaporation cycles. The analysis is limited to the ice-free period. Net radiation was substantially greater over all water-dominated surfaces compared with uplands (U). Seasonal differences were 16% greater for wetlands (W), 25% greater for small (SL) and medium (ML) lakes and 73% greater for Great Slave Lake (LL). At maximum, the seasonal heat storage relative to net radiation was 6, 9, 26, 55 and 76 % for U, W, SL, ML and LL respectively. ML and LL are slow to warm in summer but their large cumulative heat storage near summer's end has a major impact on the regional energy balance, because this heat is available to feed convective heat fluxes in fall and early winter. The evaporation season for U, W, SL, ML and LL lasts for 19, 21, 22, 24 and 30 weeks respectively. The effects of

  1. 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.

  2. 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

  3. Arctic melt ponds and energy balance in the climate system

    NASA Astrophysics Data System (ADS)

    Sudakov, Ivan

    2017-02-01

    Elements of Earth's cryosphere, such as the summer Arctic sea ice pack, are melting at precipitous rates that have far outpaced the projections of large scale climate models. Understanding key processes, such as the evolution of melt ponds that form atop Arctic sea ice and control its optical properties, is crucial to improving climate projections. These types of critical phenomena in the cryosphere are of increasing interest as the climate system warms, and are crucial for predicting its stability. In this paper, we consider how geometrical properties of melt ponds can influence ice-albedo feedback and how it can influence the equilibria in the energy balance of the planet.

  4. Adipocytes as regulators of energy balance and glucose homeostasis

    PubMed Central

    Rosen, Evan D.; Spiegelman, Bruce M.

    2011-01-01

    Adipocytes have been studied with increasing intensity as a result of the emergence of obesity as a serious public health problem and the realization that adipose tissue serves as an integrator of various physiological pathways. In particular, their role in calorie storage makes adipocytes well suited to the regulation of energy balance. Adipose tissue also serves as a crucial integrator of glucose homeostasis. Knowledge of adipocyte biology is therefore crucial for understanding the pathophysiological basis of obesity and metabolic diseases such as type 2 diabetes. Furthermore, the rational manipulation of adipose physiology is a promising avenue for therapy of these conditions. PMID:17167472

  5. 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

  6. Validating surface energy balance fluxes derived from airborne remote sensing

    NASA Astrophysics Data System (ADS)

    Chavez Eguez, Jose Luis

    Remote sensing-derived energy balance components were compared against measured eddy covariance energy balance terms using heat flux source area models to validate the airborne multispectral remote sensing procedure in the estimation of instantaneous and daily evapotranspiration rates. A procedure was developed to generate raster layers of the footprint weights for weighting/integrating the different components of the energy balance model and obtain meaningful comparisons to similar energy balance terms measured at eddy covariance and/or Bowen ratio stations. Soil heat flux and surface aerodynamic temperature models were studied in an effort to improve the remote sensing estimation of distributed evapotranspiration rates. Aerial and ground data were acquired over a riparian corridor (Salt Cedar, Tamarix grove), soybean and cornfields (rainfed crops) in different ecosystems. The results confirmed that net radiation is well estimated with the remote sensing technique showing an estimation error of only -4.8 +/- 20.7 W m-2, (-0.5 +/- 3.6%). Linear and exponential soil heat flux models were found to correlate strongly to leaf area index and net radiation. The surface aerodynamic temperature term in the sensible heat flux equation was parameterized using surface radiometric temperature, air temperature, wind speed, and leaf area index. It is suggested that the surface aerodynamic temperature model be tested for a wide range of vegetation types, atmospheric stability conditions, surface heterogeneity, and ecosystems to assess the model limitations. The flux source area footprint model "FSAM" integrated heat flux pixels that compared better to measured values and it is recommended as a standard procedure to compare airborne remote sensing-derived heat fluxes against measured fluxes by eddy covariance systems; when compared to the "FASOWG" footprint model and simple arithmetic averages. Finally, the method that uses alfalfa reference daily evapotranspiration in

  7. 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.

  8. Energy requirements for a swimming pool through a water-atmosphere energy balance

    SciTech Connect

    Almanza, F.; Lara, J. )

    1994-07-01

    The methodology displayed here is to calculate the energy requirements for heating a swimming pool to a desired temperature. This methodology consists of an energy balance between water-atmosphere as is used in the temperature evaluation of cooling ponds in power plants. Different mathematical expressions are given to calculate such a balance. It is necessary to know the month of the year, the ambient temperature, relative humidity, wind velocity, and solar radiation. With these parameters it is possible to know the natural temperature of the water, natural evaporation, energy needed to reach a determined swimming pool temperature and the evaporation of the heated pool.

  9. Energy balance regulation by endocannabinoids at central and peripheral levels.

    PubMed

    Quarta, Carmelo; Mazza, Roberta; Obici, Silvana; Pasquali, Renato; Pagotto, Uberto

    2011-09-01

    Dysregulation of the endocannabinoid system (ECS) is a universal and, perhaps, causative feature of obesity. Central nervous system (CNS) circuits that regulate food intake were initially believed to be the targets for dysregulation. However, it is increasingly evident that endocannabinoids affect food intake, energy expenditure and substrate metabolism by acting on peripheral sites. Cannabinoid type 1 receptor (CB1r) antagonists can effectively treat obesity and associated metabolic alterations but, unfortunately, cause and exacerbate mood disorders. Drugs restricted to act on peripheral CB1rs might be safer and more effective, retaining the anti-obesity effects but lacking the adverse neurodepressive reactions. This review summarizes the emerging roles of the ECS in energy balance and discusses future pharmacological approaches for developing peripherally restricted CB1r antagonists.

  10. Energy balance and photochemical processes in the inner coma

    SciTech Connect

    Huebner, W.F.; Keady, J.J.

    1982-01-01

    Energy balance and multifluid flow in the coma are described. Expansion cooling, radiative cooling, photodissociative heating, chemical heating, and relative multifluid flow are the processes determining the energy budget. In the fluid dynamics, fast atomic and molecular hydrogen are considered as separate fluids with larger collision mean free paths than the cold bulk fluid that has a larger mean molecular weight. The transition from fluid flow to free molecular flow is approximated. The model predicts hydrogen and bulk fluid flow velocities in general agreement with observations. The effects of the temperature profile and the fast hydrogen flow on the chemistry in the inner coma are investigated. Results from a model approximating conditions in Halley's comet are presented.

  11. 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.

  12. Mechanisms linking energy balance and reproduction: impact of prenatal environment.

    PubMed

    Rhinehart, Erin M

    2016-01-01

    The burgeoning field of metabolic reproduction regulation has been gaining momentum due to highly frequent discoveries of new neuroendocrine factors regulating both energy balance and reproduction. Universally throughout the animal kingdom, energy deficits inhibit the reproductive axis, which demonstrates that reproduction is acutely sensitive to fuel availability. Entrainment of reproductive efforts with energy availability is especially critical for females because they expend large amounts of energy on gestation and lactation. Research has identified an assortment of both central and peripheral factors involved in the metabolic regulation of reproduction. From an evolutionary perspective, these mechanisms likely evolved to optimize reproductive fitness in an environment with an unpredictable food supply and regular bouts of famine. To be effective, however, the mechanisms responsible for the metabolic regulation of reproduction must also retain developmental plasticity to allow organisms to adapt their reproductive strategies to their particular niche. In particular, the prenatal environment has emerged as a critical developmental window for programming the mechanisms responsible for the metabolic control of reproduction. This review will discuss the current knowledge about hormonal and molecular mechanisms that entrain reproduction with prevailing energy availability. In addition, it will provide an evolutionary, human life-history framework to assist in the interpretation of findings on gestational programming of the female reproductive function, with a focus on pubertal timing as an example. Future research should aim to shed light on mechanisms underlying the prenatal modulation of the adaptation to an environment with unstable resources in a way that optimizes reproductive fitness.

  13. 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

  14. Water-Energy balance in pressure irrigation systems

    NASA Astrophysics Data System (ADS)

    Sánchez, Raúl; Rodríguez-Sinobas, Leonor; Juana, Luis; Laguna, Francisco V.; Castañón, Guillermo; Gil, María; Benitez, Javier

    2013-04-01

    Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure -sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. Automation techniques become easier after modernization, and operation management plays an important role in energy efficiency issues. Modern systems use to include elevated water reservoirs with enough capacity to irrigate during peak water demand period about 16 to 48 h. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems according to their management possibilities. Also is an objective to estimate the fraction of the water reservoirs available along the irrigation campaign for storing the energy from renewable sources during their availability periods. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity and new opportunities in the renewable energy field.

  15. 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

  16. 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

  17. [Hypothalamic inflammation and energy balance deregulations: focus on chemokines.

    PubMed

    Le Thuc, Ophélia; Rovère, Carole

    2016-01-01

    The hypothalamus is a key brain region in the regulation of energy balance. It especially controls food intake and both energy storage and expenditure through integration of humoral, neural and nutrient-related signals and cues. Hypothalamic neurons and glial cells act jointly to orchestrate, both spatially and temporally, regulated metabolic functions of the hypothalamus. Thus, the existence of a causal link between hypothalamic inflammation and deregulations of feeding behavior, such as involuntary weight-loss or obesity, has been suggested. Among the inflammatory mediators that could induce deregulations of hypothalamic control of the energy balance, chemokines represent interesting candidates. Indeed, chemokines, primarily known for their chemoattractant role of immune cells to the inflamed site, have also been suggested capable of neuromodulation. Thus, chemokines could disrupt cellular activity together with synthesis and/or secretion of multiple neurotransmitters/mediators that are involved in the maintenance of energy balance. Here, we relate, on one hand, recent results showing the primary role of the central chemokinergic signaling CCL2/CCR2 for metabolic and behavioral adaptation to high-grade inflammation, especially loss of appetite and weight, through its activity on hypothalamic neurons producing the orexigenic peptide Melanin-Concentrating Hormone (MCH) and, on the other hand, results that suggest that chemokines could also deregulate hypothalamic neuropeptidergic circuits to induce an opposite phenotype and eventually participate in the onset/development of obesity. In more details, we will emphasize a study recently showing, in a model of high-grade acute inflammation of LPS injection in mice, that central CCL2/CCR2 signaling is of primary importance for several aspects explaining weight loss associated with inflammation: after LPS injection, animals lose weight, reduce their food intake, increase their fat oxidation (thus energy consumption from

  18. 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.

  19. p75 Neurotrophin Receptor Regulates Energy Balance in Obesity.

    PubMed

    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

    2016-01-12

    Obesity and metabolic syndrome reflect the dysregulation of molecular pathways that control energy homeostasis. Here, we show that the p75 neurotrophin receptor (p75(NTR)) controls energy expenditure in obese mice on a high-fat diet (HFD). Despite no changes in food intake, p75(NTR)-null mice were protected from HFD-induced obesity and remained lean as a result of increased energy expenditure without developing insulin resistance or liver steatosis. p75(NTR) 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 p75(NTR) or transplantation of p75(NTR)-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 p75(NTR) to cAMP/PKA regulates energy balance and suggest that non-CNS neurotrophin receptor signaling could be a target for treating obesity and the metabolic syndrome.

  20. 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

  1. 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

  2. Energy Balance for Random Vibrations of Piecewise-Conservative Systems

    NASA Astrophysics Data System (ADS)

    IOURTCHENKO, D. V.; DIMENTBERG, M. F.

    2001-12-01

    Vibrations of systems with instantaneous or stepwise energy losses, e.g., due to impacts with imperfect rebounds, dry friction forces(s) (in which case the losses may be treated as instantaneous ones by appropriate introduction of the response energy) and/or active feedback “bang-bang” control of the systems' response are considered. Response of such (non-linear) systems to a white-noise random excitation is considered for the case where there are no other response energy losses. Thus, a simple linear energy growth with time between “jumps” is observed. Explicit expressions for the expected response energy are derived by direct application of the stochastic differential equations calculus, which contains the expected time interval between two consecutive jumps. The latter may be predicted as a solution to the relevant first-passage problem. Perturbational analysis of the relevant PDE for this problem for a certain vibroimpact system demonstrated the possibility for using the solution to the corresponding free vibration problem as a zero order approximation. The method is applied to an s.d.o.f. system with a feedback inertia control, designed according to a certain previously introduced “generalized reversed swings law”. Extensive Monte-Carlo simulation results are presented for this system as well as for several previously analyzed ones: system with impacts; system with dry friction; system with stiffness control; pendulum with controlled length. The results are compared with those due to the asymptotic stochastic averaging approach. Both methods are shown to provide adequate accuracy far beyond the expected applicability range of the asymptotic approach (which requires both excitation intensity and losses to be small), with direct energy balance being generally superior.

  3. 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.

  4. Evaluating the effect of measurement error when using one or two 24 h dietary recalls to assess eating out: a study in the context of the HECTOR project.

    PubMed

    Orfanos, Philippos; Knüppel, Sven; Naska, Androniki; Haubrock, Jennifer; Trichopoulou, Antonia; Boeing, Heiner

    2013-09-28

    Eating out is often recorded through short-term measurements and the large within-person variability in intakes may not be adequately captured. The present study aimed to understand the effect of measurement error when using eating-out data from one or two 24 h dietary recalls (24hDR), in order to describe intakes and assess associations between eating out and personal characteristics. In a sample of 366 adults from Potsdam, Germany, two 24hDR and a FFQ were collected. Out-of-home intakes were estimated based on either one 24hDR or two 24hDR or the Multiple Source Method (MSM) combining the two 24hDR and the questionnaire. The distribution of out-of-home intakes of energy, macronutrients and selected foods was described. Multiple linear regression and partial correlation coefficients were estimated to assess associations between out-of-home energy intake and participants' characteristics. The mean daily out-of-home intakes estimated from the two 24hDR were similar to the usual intakes estimated through the MSM. The out-of-home energy intake, estimated through either one or two 24hDR, was positively associated with total energy intake, inversely with age and associations were stronger when using the two 24hDR. A marginally significant inverse association between out-of-home energy intake and physical activity at work was observed only on the basis of the two 24hDR. After applying the MSM, all significant associations remained and were more precise. Data on eating out collected through one or two 24hDR may not adequately describe intake distributions, but significant associations between eating out and participants' characteristics are highly unlikely to appear when in reality these do not exist.

  5. An energy-balance model of glaciation cycles

    NASA Technical Reports Server (NTRS)

    Ghil, M.; Bhattacharya, K.

    1979-01-01

    A one dimensional energy balance model is presented which contains a time lagged albedo to account for the delayed dependence of continental ice sheets on temperature; it also includes a smoothing of temperature gradients in the tropics to account for the effect of the Hadley circulation on the strong flattening of meridional temperature profiles there. The model exhibits finite amplitude, sustained free oscillations; these oscillations are triggered by a change in the insulation parameter and occur in the absence of any external forcing. This model behavior strongly suggests the possibility of an almost-intransitive mechanism playing a role in glaciation cycles. This behavior also occurs on shorter time scales which might be relevant to the interannual variability of the atmosphere.

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

    NASA Astrophysics Data System (ADS)

    Kim, Joon; Verma, Shashi B.

    1990-06-01

    Eddy correlation measurements were made of fluxes of moisture, heat and momentum at a tallgrass prairie site near Manhattan, Kansas, U.S.A. during the First ISLSCP ISLSCP: International Satellite Land Surface Climatology Project (for details, see Sellers et al., 1988). Field Experiment (FIFE) in 1987. The study site is dominated by three C4 grass species: big bluestem ( Andropogon gerardii), indiangrass ( Sorghastrum nutans), and switchgrass ( Panicum virgatum). The stomatal conductance and leaf water potential of these grass species were also measured. In this paper, daily and seasonal variations in the components of the surface energy balance are examined. The aerodynamic and canopy surface conductances for the prairie vegetation are also evaluated.

  7. 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.

  8. A stability theorem for energy-balance climate models

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; North, G. R.

    1979-01-01

    The paper treats the stability of steady-state solutions of some simple, latitude-dependent, energy-balance climate models. For north-south symmetric solutions of models with an ice-cap-type albedo feedback, and for the sum of horizontal transport and infrared radiation given by a linear operator, it is possible to prove a 'slope stability' theorem, i.e., if the local slope of the steady-state iceline latitude versus solar constant curve is positive (negative) the steady-state solution is stable (unstable). Certain rather weak restrictions on the albedo function and on the heat transport are required for the proof, and their physical basis is discussed.

  9. Geospatial and Contextual Approaches to Energy Balance and Health.

    PubMed

    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

    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.

  10. 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.

  11. 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.

  12. Local geodetic and seismic energy balance for shallow earthquake prediction

    NASA Astrophysics Data System (ADS)

    Cannavó, Flavio; Arena, Alessandra; Monaco, Carmelo

    2015-01-01

    Earthquake analysis for prediction purposes is a delicate and still open problem largely debated among scientists. In this work, we want to show that a successful time-predictable model is possible if based on large instrumental data from dense monitoring networks. To this aim, we propose a new simple data-driven and quantitative methodology which takes into account the accumulated geodetic strain and the seismically-released strain to calculate a balance of energies. The proposed index quantifies the state of energy of the selected area and allows us to evaluate better the ingoing potential seismic risk, giving a new tool to read recurrence of small-scale and shallow earthquakes. In spite of its intrinsic simple formulation, the application of the methodology has been successfully simulated in the Eastern flank of Mt. Etna (Italy) by tuning it in the period 2007-2011 and testing it in the period 2012-2013, allowing us to predict, within days, the earthquakes with highest magnitude.

  13. 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.

  14. Estimate of dietary phosphorus intake using 24-h urine collection.

    PubMed

    Morimoto, Yuuka; Sakuma, Masae; Ohta, Hiroyuki; Suzuki, Akitsu; Matsushita, Asami; Umeda, Minako; Ishikawa, Makoto; Taketani, Yutaka; Takeda, Eiji; Arai, Hidekazu

    2014-07-01

    Increases in serum phosphorus levels and dietary phosphorus intake induces vascular calcification, arterial sclerosis and cardiovascular diseases. Limiting phosphorus intake is advisable, however, no assessment methods are capable of estimating dietary phosphorus intake. We hypothesized that urinary phosphorus excretion can be translated into estimation of dietary phosphorus intake, and we evaluated whether a 24-h urine collection method could estimate dietary phosphorus intake. Thirty two healthy subjects were recruited for this study. Subjects collected urine samples over 24 h and weighed dietary records. We calculated dietary protein intake and phosphorus intake from dietary records and urine collection, and investigated associations between the two methods in estimating protein and phosphorus intake. Significant positive correlations were observed between dietary records and UC for protein and phosphorus intake. The average intakes determined from dietary records were significantly higher than from urine collection for both protein and phosphorus. There was a significant positive correlation between both the phosphorus and protein difference in dietary records and urine collection. The phosphorus-protein ratio in urine collection was significantly higher than in dietary records. Our data indicated that the 24-h urine collection method can estimate the amount of dietary phosphorus intake, and the results were superior to estimation by weighed dietary record.

  15. 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).

  16. 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.

  17. Phenotypic clines, energy balances and ecological responses to climate change.

    PubMed

    Buckley, Lauren B; Nufio, César R; Kingsolver, Joel G

    2014-01-01

    The Metabolic Theory of Ecology has renewed interest in using energetics to scale across levels of ecological organization. Can scaling from individual phenotypes to population dynamics provides insight into why species have shifted their phenologies, abundances and distributions idiosyncratically in response to recent climate change? We consider how the energetic implications of phenotypes may scale to understand population and species level responses to climate change using four focal grasshopper species along an elevation gradient in Colorado. We use a biophysical model to translate phenotypes and environmental conditions into estimates of body temperatures. We measure thermal tolerances and preferences and metabolic rates to assess rates of energy use and acquisition. Body mass declines along the elevation gradient for all species, but mass-specific metabolic rates increases only modestly. We find interspecific differences in both overall thermal tolerances and preferences and in the variation of these metrics along the elevation gradient. The more dispersive species exhibit significantly higher thermal tolerance and preference consistent with much of their range spanning hot, low elevation areas. When integrating these metrics to consider metabolic constraints, we find that energetic costs decrease along the elevation gradient due to decreasing body size and temperature. Opportunities for energy acquisition, as reflected by the proportion of time that falls within a grasshopper's thermal tolerance range, peak at mid elevations. We discuss methods for translating these energetic metrics into population dynamics. Quantifying energy balances and allocation offers a viable approach for predicting how populations will respond to climate change and the consequences for species composed of populations that may be locally adapted.

  18. A balanced filterless K-edge energy window multilayer detector for dual energy computed tomography

    NASA Astrophysics Data System (ADS)

    Allec, Nicholas; Karim, Karim S.

    2010-04-01

    Ross (or balanced) filter-based systems have been studied extensively in the past, however they have only recently been studied for medical applications such as computed tomography and contrast-enhanced mammography. Balanced filters are filters composed of different materials which have thicknesses designed to match the attenuation for all radiation energies except those within a certain energy window (between the K-edges of the filter materials). Images obtained using different filters to attenuate the incident x-rays can be subtracted to obtain an image which contains information solely within the energy window. The disadvantage of this image acquisition method is the requirement of a separate exposure for each filter. This can lead to motion artifacts in the resulting image for example due to cardiac, respiratory, or patient movement. In this paper we investigate a filterless, multilayer detector design using the general concept of balanced filters. In the proposed detector, energy discrimination is achieved using stacked layers of different conversion materials. Similar to how the thicknesses of balanced filters are chosen, the thicknesses of the conversion layers are designed to match the attenuation of x-rays except between the K-edges of the conversion materials. Motion artifacts are suppressed in the final image due to the simultaneous acquisition of images on all layers during a single exposure. The proposed multilayer design can be used for a number of applications depending on the energy range of interest. To study the proposed design, we consider dual energy computed tomography (CT) using a gadolinium-based contrast agent.

  19. 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 ...

  20. High-fat meals reduce 24-h circulating leptin concentrations in women.

    PubMed

    Havel, P J; Townsend, R; Chaump, L; Teff, K

    1999-02-01

    Leptin induces weight loss in rodents via its effects on food intake and energy expenditure. High-fat diets induce weight gain, but the mechanism is not well understood. Previous studies have not found an effect of dietary fat content on fasting leptin. There is a nocturnal increase of leptin, however, which is related to insulin responses to meals. We have reported that adipocyte glucose utilization is involved in insulin-induced leptin secretion in vitro. Accordingly, high-fat, low-carbohydrate (HF/LC) meals, which induce smaller insulin and glucose responses, would produce lower leptin concentrations than low-fat, high-carbohydrate (LF/HC) meals. Blood samples were collected every 30-60 min for 24 h from 19 normal-weight (BMI, 24.2 +/- 0.7 kg/m2; percent body fat = 31 +/- 1%) women on 2 days (10 days apart) during which the subjects were randomized to consume three isocaloric 730-kcal meals containing either 60/20 or 20/60% of energy as fat/carbohydrate. Overall insulin and glycemic responses (24-h area under the curve [AUC]) were reduced by 55 and 61%, respectively, on the HF/LC day (P < 0.0001). During LF/HC feeding, there were larger increases of leptin 4-6 h after breakfast (38 +/- 7%, P < 0.001) and lunch (78 +/- 14%, P < 0.001) than after HF/LC meals (both P < 0.02). During LF/HC feeding, leptin increased from a morning baseline of 10.7 +/- 1.6 ng/ml to a nocturnal peak of 21.3 +/- 1.3 ng/ml (change, 10.6 +/- 1.3 ng/ml; percent change, 123 +/- 16%; P < 0.0001). The amplitudes of the nocturnal rise of leptin and the 24-h leptin AUC were 21 +/- 8% (P < 0.005) and 38 +/- 12% (P < 0.0025) larger, respectively, on the LF/HC day. In summary, consumption of HF/LC meals results in lowered 24-h circulating leptin concentrations. This result may be a consequence of decreased adipocyte glucose metabolism. Decreases of 24-h circulating leptin could contribute to the weight gain during consumption of high-fat diets.

  1. 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.

  2. Daily energy balance in growth hormone receptor/binding protein (GHR -/-) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency.

    PubMed

    Longo, Kenneth A; Berryman, Darlene E; Kelder, Bruce; Charoenthongtrakul, Soratree; Distefano, Peter S; Geddes, Brad J; Kopchick, John J

    2010-02-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR -/- mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (M(b)) changes and physical activity in 17month-old female GHR -/- mice and their age-matched wild type littermates. The GHR -/- mice were smaller, consumed more food per unit M(b), had greater EE per unit M(b) and had an increase in 24-h EE/M(b) that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR -/- mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, M(b) and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for M(b) and LMA, the GHR -/- mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR -/- mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR -/- mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final 3h of the dark phase. Therefore, we conclude that GHR -/- mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable M(b). Relative to wild type mice, the GHR -/- mice consumed more calories per unit M(b), which offset the disproportionate increase in their daily energy expenditure. While GHR -/- mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA.

  3. Daily energy balance in growth hormone receptor/binding protein (GHR−/−) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency

    PubMed Central

    Longo, Kenneth A.; Berryman, Darlene E.; Kelder, Bruce; Charoenthongtrakul, Soratree; DiStefano, Peter S.; Geddes, Brad J.; Kopchick, John

    2009-01-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR −/− mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (Mb) changes and physical activity in 17 month-old female GHR −/− mice and their age-matched wild type littermates. The GHR −/− mice were smaller, consumed more food per unit Mb, had greater EE per unit Mb and had an increase in 24-h EE/Mb that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR −/− mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, Mb and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for Mb and LMA, the GHR −/− mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR −/− mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR −/− mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final three hours of the dark phase. Therefore, we conclude that GHR −/− mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable Mb. Relative to wild type mice, the GHR −/− mice consumed more calories per unit Mb, which offset the disproportionate increase in their daily energy expenditure. While GHR −/− mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

  4. The Global Energy Balance Archive (GEBA): A database for the worldwide measured surface energy fluxes

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Ohmura, Atsumu; Schär, Christoph; Müller, Guido; Hakuba, Maria Z.; Mystakidis, Stefanos; Arsenovic, Pavle; Sanchez-Lorenzo, Arturo

    2017-02-01

    The Global Energy Balance Archive (GEBA) is a database for the worldwide measured energy fluxes at the Earth's surface. GEBA is maintained at ETH Zurich (Switzerland) and has been founded in the 1980s by Prof. Atsumu Ohmura. It has continuously been updated and currently contains around 2500 stations with 500`000 monthly mean entries of various surface energy balance components. Many of the records extend over several decades. The most widely measured quantity available in GEBA is the solar radiation incident at the Earth's surface ("global radiation"). The data sources include, in addition to the World Radiation Data Centre (WRDC) in St. Petersburg, data reports from National Weather Services, data from different research networks (BSRN, ARM, SURFRAD), data published in peer-reviewed publications and data obtained through personal communications. Different quality checks are applied to check for gross errors in the dataset. GEBA is used in various research applications, such as for the quantification of the global energy balance and its spatiotemporal variation, or for the estimation of long-term trends in the surface fluxes, which enabled the detection of multi-decadal variations in surface solar radiation, known as "global dimming" and "brightening". GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible over the internet via www.geba.ethz.ch.

  5. Assessing circumbinary habitable zones using latitudinal energy balance modelling

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan

    2014-01-01

    Previous attempts to describe circumbinary habitable zones (HZs) have been concerned with the spatial extent of the zone, calculated analytically according to the combined radiation field of both stars. By contrast to these `spatial HZs', we present a numerical analysis of the `orbital HZ', an HZ defined as a function of planet orbital elements. This orbital HZ is better equipped to handle (for example) eccentric planet orbits, and is more directly connected to the data returned by exoplanet observations. Producing an orbital HZ requires a large number of climate simulations to be run to investigate the parameter space - we achieve this using latitudinal energy balance models, which handle the insolation of the planet by both stars (including mutual eclipses), as well as the planetary atmosphere's ability to absorb, transfer and lose heat. We present orbital HZs for several known circumbinary planetary systems: Kepler-16, Kepler-34, Kepler-35, Kepler-47 and PH-1. Generally, the orbital HZs at zero eccentricity are consistent with spatial HZs derived by other authors, although we detect some signatures of variability that coincide with resonances between the binary and planet orbital periods. We confirm that Earth-like planets around Kepler-47 with Kepler-47c's orbital parameters could possess liquid water, despite current uncertainties regarding its eccentricity. Kepler-16b is found to be outside the HZ, as well as the other circumbinary planets investigated.

  6. BALANCE (Bioengineering Approaches for Lifestyle Activity and Nutrition Continuous Engagement): Developing New Technology for Monitoring Energy Balance in Real Time

    PubMed Central

    Hughes, Deonna C.; Andrew, Adrienne; Denning, Tamara; Hurvitz, Philip; Lester, Jonathan; Beresford, Shirley; Borriello, Gaetano; Bruemmer, Barbara; Moudon, Anne Vernez; Duncan, Glen E.

    2010-01-01

    Methods that measure energy balance accurately in real time represent promising avenues to address the obesity epidemic. We developed an electronic food diary on a mobile phone that includes an energy balance visualization and computes and displays the difference between energy intake from food entries and energy expenditure from a multiple-sensor device that provides objective estimates of energy expenditure in real time. A geographic information system dataset containing locations associated with activity and eating episodes is integrated with an ArcPad mapping application on the phone to provide users with a visual display of food sources and locations associated with physical activity within their proximal environment. This innovative tool captures peoples' movement through space and time under free-living conditions and could potentially have many health-related applications in the future. PMID:20307404

  7. Beyond Leptin: Emerging Candidates for the Integration of Metabolic and Reproductive Function during Negative Energy Balance.

    PubMed

    True, Cadence; Grove, Kevin L; Smith, M Susan

    2011-01-01

    Reproductive status is tightly coupled to metabolic state in females, and ovarian cycling in mammals is halted when energy output exceeds energy input, a metabolic condition known as negative energy balance. This inhibition of reproductive function during negative energy balance occurs due to suppression of gonadotropin-releasing hormone (GnRH) release in the hypothalamus. The GnRH secretagogue kisspeptin is also inhibited during negative energy balance, indicating that inhibition of reproductive neuroendocrine circuits may occur upstream of GnRH itself. Understanding the metabolic signals responsible for the inhibition of reproductive pathways has been a compelling research focus for many years. A predominant theory in the field is that the status of energy balance is conveyed to reproductive neuroendocrine circuits via the adipocyte hormone leptin. Leptin is stimulatory for GnRH release and lower levels of leptin during negative energy balance are believed to result in decreased stimulatory drive for GnRH cells. However, recent evidence found that restoring leptin to physiological levels did not restore GnRH function in three different models of negative energy balance. This suggests that although leptin may be an important permissive signal for reproductive function as indicated by many years of research, factors other than leptin must critically contribute to negative energy balance-induced reproductive inhibition. This review will focus on emerging candidates for the integration of metabolic status and reproductive function during negative energy balance.

  8. Beyond Leptin: Emerging Candidates for the Integration of Metabolic and Reproductive Function during Negative Energy Balance

    PubMed Central

    True, Cadence; Grove, Kevin L.; Smith, M. Susan

    2011-01-01

    Reproductive status is tightly coupled to metabolic state in females, and ovarian cycling in mammals is halted when energy output exceeds energy input, a metabolic condition known as negative energy balance. This inhibition of reproductive function during negative energy balance occurs due to suppression of gonadotropin-releasing hormone (GnRH) release in the hypothalamus. The GnRH secretagogue kisspeptin is also inhibited during negative energy balance, indicating that inhibition of reproductive neuroendocrine circuits may occur upstream of GnRH itself. Understanding the metabolic signals responsible for the inhibition of reproductive pathways has been a compelling research focus for many years. A predominant theory in the field is that the status of energy balance is conveyed to reproductive neuroendocrine circuits via the adipocyte hormone leptin. Leptin is stimulatory for GnRH release and lower levels of leptin during negative energy balance are believed to result in decreased stimulatory drive for GnRH cells. However, recent evidence found that restoring leptin to physiological levels did not restore GnRH function in three different models of negative energy balance. This suggests that although leptin may be an important permissive signal for reproductive function as indicated by many years of research, factors other than leptin must critically contribute to negative energy balance-induced reproductive inhibition. This review will focus on emerging candidates for the integration of metabolic status and reproductive function during negative energy balance. PMID:22645510

  9. 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.

  10. 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.

  11. Heat storage in forest biomass improves energy balance closure

    NASA Astrophysics Data System (ADS)

    Lindroth, A.; Mölder, M.; Lagergren, F.

    2010-01-01

    Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation very well. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance

  12. Analysis of the temperature dynamics of a proglacial river using time-lapse thermal imaging and energy balance modeling

    NASA Astrophysics Data System (ADS)

    Cardenas, M. Bayani; Doering, Michael; Rivas, Denny S.; Galdeano, Carlos; Neilson, Bethany T.; Robinson, Christopher T.

    2014-11-01

    Understanding the temperature dynamics of rivers is critical for their management and for ecological and biogeochemical aquatic processes. In proglacial rivers, there is typically a paucity of thermal observations which in turn limits the understanding of these sensitive and evolving environments. Here we collected ground-based thermal images, with approximately meter resolution and imaged every half hour for 24 h, of a proglacial river and 2 km2 of its floodplain and interpret the observations using a numerical energy balance model. The images revealed the longitudinal thermal pattern of the Urbach River in Switzerland - there was gradual cooling in the upstream half of the study section and then warming in the remaining downstream portion. This pattern persisted through the diurnal warming and cooling cycle. The spatio-temporal thermal pattern was explained by a model that included distributed thermal inputs of cooler water in the upstream half coming from alluvial fans and warmer water in the downstream half running off steep cliffs that warm snowmelt. The warm inputs from the cliffs were confirmed by the thermal imaging. These data and the associated modeling illustrated that distributed inflows can overwhelm the influence of atmospheric fluxes, and that their knowledge is critical for understanding stream temperatures. The combination of modeling and detailed time-lapse thermal imaging allowed for identification and quantification of processes critical to in-stream temperature dynamics in a proglacial river.

  13. Environment-physiology, diet quality and energy balance: the influence of early life nutrition on future energy balance.

    PubMed

    Burdge, Graham C; Lillycrop, Karen A

    2014-07-01

    Diseases caused by impaired regulation of energy balance, in particular obesity, represent a major global health burden. Although polymorphisms, lifestyle and dietary choices have been associated with differential risk of obesity and related conditions, a substantial proportion of the variation in disease risk remains unexplained. Evidence from epidemiological studies, natural experiments and from studies in animal models has shown that a poor intra-uterine environment is associated causally with increased risk of obesity and metabolic disease in adulthood. Induction of phenotypes that increase disease risk involves the fetus receiving cues from the mother about the environment which, via developmental plasticity, modify the phenotype of the offspring to match her environment. However, inaccurate information may induce an offspring phenotype that is mismatched to the future environment. Such mismatch has been suggested to underlie increased risk of metabolic disease associated with a poor early life environment. Recent studies have shown that induction of modified phenotypes in the offspring involves altered epigenetic regulation of specific genes. Identification of a central role of epigenetics in the aetiology of obesity and metabolic disease may facilitate the development of novel therapeutic interventions and of biomarkers of disease risk.

  14. 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...

  15. 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.

  16. Impact of seasonal scarcity on energy balance and body composition in peasant adolescents from Calakmul, Campeche Mexico.

    PubMed

    Gamboa, José A Alayón; García, Francisco D Gurri

    2007-01-01

    A time allocation and anthropometric study were performed on 46 male and 38 female adolescents from 16 peasant households from two different adaptive strategies in the municipio of Calakmul, Campeche Mexico to see if they could maintain energy balance during the annual scarcity season. These strategies were called: "household subsistence agricultural strategy" (HSA) and "household commercial agricultural strategy" (HCA). Each month, from June 2001 to May 2002, adolescents were measured and followed for 24 h. Their activities were recorded at 15 min intervals. Weight for age (W/A), height for age (H/A), body mass index (BMI), arm muscle area, arm fat area, total energy expenditure (TEE), activity energy expenditure (AEE), and basal metabolic rate (BMR) were estimated and the data compared between seasons using a repeated measurements analysis of variance. The results suggest that HCA offers their adolescents better buffering against seasonal scarcity, and that HSA males are better protected than females. HCA adolescents didn't show significant losses of weight, and HCA females lost body fat during the scarcity season. HSA vulnerability was observed in W/A and BMI z score reductions during the scarcity season. It also reflected itself in stunted adolescent males and adolescent females with fewer fat reserves. HSA adolescents reduced their BMR to down regulate their energy expenditure during the scarcity season without reducing TEE and physical activity levels. HSA females lost muscle mass during the scarcity season while HSA males didn't. This difference was associated with a more demanding work schedule throughout the year for females.

  17. 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.

  18. System analysis of a bio-energy plantation: full greenhouse gas balance and energy accounting (POPFULL)

    NASA Astrophysics Data System (ADS)

    Ceulemans, R.; Janssens, I.; Berhongaray, G.; Broeckx, L.; De Groote, T.; ElKasmioui, O.; Fichot, R.; Njakou Djomo, S.; Verlinden, M.; Zona, D.

    2011-12-01

    In recent year the environmental impact of fossil fuels and their reduced availability are leading to an increasing interest in renewable energy sources, among them bio-energy. However, the cost/benefit in establishing, managing, and using these plantations for energy production should be quantified together with their environmental impact. In this project we are performing a full life cycle analysis (LCA) balance of the most important greenhouse gases (CO2, CH4, N2O, H2O and O3), together with full energy accounting of a short-rotation coppice (SRC) plantation with fast-growing trees. We established the plantation two years ago and we have been monitoring net fluxes of CO2, N2O, CH4, and O3, in combination with biomass pools (incl. soil) and fluxes, and volatile organic carbon (VOCs). This poplar plantation will be monitored for another two years then harvested and transformed into bio-energy. For the energy accounting we are performing a life cycle analysis and energy efficiency assessments over the entire cycle of the plantation until the production of electricity and heat. Here we present an overview of the results from the first two years from the plantation establishment, and some of the projections based on these first results.

  19. Alternative strategies for energy recovery from municipal solid waste Part A: Mass and energy balances.

    PubMed

    Consonni, S; Giugliano, M; Grosso, M

    2005-01-01

    This two-part paper assesses four strategies for energy recovery from municipal solid waste (MSW) by dedicated waste-to-energy (WTE) plants generating electricity through a steam cycle. The feedstock is the residue after materials recovery (MR), assumed to be 35% by weight of the collected MSW. In strategy 1, the MR residue is fed directly to a grate combustor. In strategy 2, the MR residue is first subjected to light mechanical treatment. In strategies 3 and 4, the MR residue is converted into RDF, which is combusted in a fluidized bed combustor. To examine the relevance of scale, we considered a small waste management system (WMS) serving 200,000 people and a large WMS serving 1,200,000 people. A variation of strategy 1 shows the potential of cogeneration with district heating. The assessment is carried out by a Life Cycle Analysis where the electricity generated by the WTE plant displaces electricity generated by fossil fuel-fired steam plants. Part A focuses on mass and energy balances, while Part B focuses on emissions and costs. Results show that treating the MR residue ahead of the WTE plant reduces energy recovery. The largest energy savings are achieved by combusting the MR residue "as is" in large scale plants; with cogeneration, primary energy savings can reach 2.5% of total societal energy use.

  20. 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.

  1. The Analysis of the Development Dynamics and Structural Balance of Solar Energy in the World

    NASA Astrophysics Data System (ADS)

    Brand, A. E.; Chekardovskiy, S. M.; Akulov, K. A.

    2017-01-01

    The paper presents data the analysis of the development dynamics and structural balance of solar energy in the world. In the article presents information about total installed production capacity of solar energy, the world solar energy production capacity distribution and the European Union energy market structure in 2000 and 2015 years.

  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. Trends in Research on Energy Balance Supported by the National Cancer Institute

    PubMed Central

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

    2013-01-01

    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

  4. 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

  5. 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.

  6. 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 ...

  7. 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...

  8. 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...

  9. 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

  10. 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...

  11. 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.

  12. 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.

  13. Energy balance in laser ablation of metal targets

    SciTech Connect

    Sobral, H.; Villagran-Muniz, M.; Bredice, F.

    2005-10-15

    Laser-generated plasma was induced on metallic targets glued to a piezoelectric microphone and placed between the plates of a planar charged capacitor. The plasma generates a temporal redistribution of electric charge on the plates that can easily be measured by a resistor connected to the ground plate; this signal is proportional to the total number of ions removed by breakdown. Both the absorbed and scattered energies were simultaneously monitored by the photoacoustic signal and an energy meter. From these signals it was possible to determine the energy involved in each of the processes. Just above the ablation threshold most of the delivered energy is absorbed and the acoustic signal prevails compared to other contributions. Above this region, the electric signal, which is proportional to the energy involved in the ablation process, becomes dominant.

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

    PubMed Central

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

    2016-01-01

    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

  15. 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

  16. 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.

  17. 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.

  18. 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)

  19. 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.

  20. 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.)

  1. 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

    2012-11-06

    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.

  2. Soil heat flux and day time surface energy balance closure at astronomical observatory, Thiruvananthapuram, south Kerala

    NASA Astrophysics Data System (ADS)

    Roxy, M. S.; Sumithranand, V. B.; Renuka, G.

    2014-06-01

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were made in the year 2008 using soil temperature data at Astronomical Observatory, Thiruvananthapuram, south Kerala. Hourly values of soil heat flux from 00 to 24 LST are presented for selected days typical of the winter, pre-monsoon, SW monsoon and NE monsoon seasons. The diurnal variation is characterized by a cross-over from negative to positive values at 0700 h, occurrence of maximum around noon and return to negative values in the late evening. The energy storage term for the soil layer 0-0.05 m is calculated and the ground heat flux G ∗ is estimated in all seasons. Daytime surface energy balance at the surface on wet and dry seasons is investigated. The average Bowen's ratio during the wet and dry seasons were 0.541 and 0.515, respectively indicating that considerable evaporation takes place at the surface. The separate energy balance components were examined and the mean surface energy balance closure was found to be 0.742 and 0.795 for wet and dry seasons, respectively. When a new method that accounts for both soil thermal conduction and soil thermal convection was adopted to calculate the surface heat flux, the energy balance closure was found to be improved. Thus on the land surface under study, the soil vertical water movement is significant.

  3. 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.

  4. 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...

  5. 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…

  6. 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.

  7. 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

  8. 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...

  9. 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.

  10. Energy Balanced Strategies for Maximizing the Lifetime of Sparsely Deployed Underwater Acoustic Sensor Networks

    PubMed Central

    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

  11. 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

  12. Berberine interfered with breast cancer cells metabolism, balancing energy homeostasis.

    PubMed

    Tan, Wen; Li, Ning; Tan, Rui; Zhong, Zhangfeng; Suo, Zhanwei; Yang, Xian; Wang, Yitao; Hu, Xiaodong

    2015-01-01

    Berberine exerted anti-cancer effect in various cancer cell lines, and was also implied in the treatment of metabolic related diseases. Given the metabolic modulation, we hypothesized that berberine possessed anti-cancer effect under the assistance of metabolic interference. Working as a modulator, metabolic enzyme inhibitor or complex network regulator in energy metabolism, berberine was highlighted in current cancer research. A reasonable cross talk between Chinese medicine and energy homeostasis provided a solid foundation for berberine interference on cancer cells reprogramming metabolism. Our result showed that berberine regulated the reprogramming metabolism through three aspects simultaneously, including mitochondrial oxidative phosphorylation, glycolysis and macromolecular synthesis. This interference with reprogramming metabolism was a continuous, simultaneous and sustainable approach in a moderate mode. And it could be regarded as a gentle and virtuous cycle from a multi-level perspective, indicating an integrated approach in cancer therapy. Meanwhile, we thought that Chinese medicine could link cancer and metabolic related diseases from a dynamic perspective through integrated network pharmacology. This cross talk would be a realistic and significant strategy for anti-cancer drug discovery and needs further investigation in future.

  13. The 24 h blood pressure-R-R interval relation in ambulatory monitoring.

    PubMed

    Recordati, Giorgio; Zanchetti, Alberto

    2008-05-30

    The present study was aimed at investigating whether the blood pressure-R-R interval relation obtained by ABPM may give useful information about autonomic control in the 24 h period. To this purpose ABPM was performed in 60 healthy young subjects (30 females and 30 males, mean age 21.8+/-1.0 years) and the collected variables were copied to a software program to convert heart rate into R-R interval values, for statistical analysis and graphic representation. The following data were calculated: 1) day and night means+/-SD; 2) difference and percent difference in mean night less mean day R-R interval (Delta y), diastolic and systolic blood pressures (Delta x) and their Delta y/Delta x ratios; 3) intercept (a_24 h), slope (b_24 h) and r coefficient (r_24 h) of the linear regressions of 24 h R-R interval over diastolic and systolic blood pressure values. In all subjects night, with respect to day, was characterized by R-R interval lengthening and blood pressure lowering. Despite this common pattern, day and night means and SDs, night and day differences, Delta y/Delta x ratios, a_24 h and b_24 h were different from individual to individual, but they were characteristic and reproducible in 20 out of the 21 subjects in which ABPM was repeated twice. Subjects could thus be classified according to their Delta y/Delta x ratios and slope (b_24 h). The 24 h blood pressure-R-R interval relation as calculated from ABPM yields individually characteristic indices of circadian sympatho-vagal reciprocity. This novel approach may be helpful in characterizing the 24 h autonomic control of several groups of patients.

  14. 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

  15. Current trends in targeting the hormonal regulation of appetite and energy balance to treat obesity

    PubMed Central

    Valentino, Michael A; Colon-Gonzalez, Francheska; Lin, Jieru E; Waldman, Scott A

    2011-01-01

    With the eruption of the obesity pandemic over the past few decades, much research has been devoted to understanding the molecular mechanisms by which the human body regulates energy balance. These studies have revealed several mediators, including gut/pancreatic/adipose hormones and neuropeptides that control both short- and long-term energy balance by regulating appetite and/or metabolism. These endogenous mediators of energy balance have been the focus of many anti-obesity drug-development programs aimed at either amplifying endogenous anorexigenic/lipolytic signaling or blocking endogenous orexigenic/lipogenic signaling. Here, we discuss the efficacy and safety of targeting these pathways for the pharmacologic treatment of obesity. PMID:21297878

  16. 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).

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

    NASA Astrophysics Data System (ADS)

    van der Tol, Christiaan; 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).

  18. 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.

  19. 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.

  20. Effect of mosaic representation of vegetation in land surface schemes on simulated energy and carbon balances

    NASA Astrophysics Data System (ADS)

    Li, R.; Arora, V. K.

    2011-06-01

    Energy and carbon balance implications of representing vegetation using a composite or mosaic approach in a land surface scheme are investigated. In the composite approach the attributes of different plant functional types (PFTs) present in a grid cell are aggregated in some fashion for energy and water balance calculations. The resulting physical environmental conditions (including net radiation, soil moisture and soil temperature) are common to all PFTs and affect their ecosystem processes. In the mosaic approach energy and water balance calculations are performed separately for each PFT tile using its own vegetation attributes, so each PFT "sees" different physical environmental conditions and its carbon balance evolves somewhat differently from that in the composite approach. Simulations are performed at selected boreal, temperate and tropical locations to illustrate the differences caused by using the composite versus the mosaic approaches of representing vegetation. Differences in grid averaged primary energy fluxes are generally less than 5 % between the two approaches. Grid-averaged carbon fluxes and pool sizes can, however, differ by as much as 46 %. Simulation results suggest that differences in carbon balance between the two approaches arise primarily through differences in net radiation which directly affects net primary productivity, and thus leaf area index and vegetation biomass.

  1. Effect of mosaic representation of vegetation in land surface schemes on simulated energy and carbon balances

    NASA Astrophysics Data System (ADS)

    Li, R.; Arora, V. K.

    2012-01-01

    Energy and carbon balance implications of representing vegetation using a composite or mosaic approach in a land surface scheme are investigated. In the composite approach the attributes of different plant functional types (PFTs) present in a grid cell are aggregated in some fashion for energy and water balance calculations. The resulting physical environmental conditions (including net radiation, soil moisture and soil temperature) are common to all PFTs and affect their ecosystem processes. In the mosaic approach energy and water balance calculations are performed separately for each PFT tile using its own vegetation attributes, so each PFT "sees" different physical environmental conditions and its carbon balance evolves somewhat differently from that in the composite approach. Simulations are performed at selected boreal, temperate and tropical locations to illustrate the differences caused by using the composite versus mosaic approaches of representing vegetation. These idealized simulations use 50% fractional coverage for each of the two dominant PFTs in a grid cell. Differences in simulated grid averaged primary energy fluxes at selected sites are generally less than 5% between the two approaches. Simulated grid-averaged carbon fluxes and pool sizes at these sites can, however, differ by as much as 46%. Simulation results suggest that differences in carbon balance between the two approaches arise primarily through differences in net radiation which directly affects net primary productivity, and thus leaf area index and vegetation biomass.

  2. Resistant starch and energy balance: impact on weight loss and maintenance.

    PubMed

    Higgins, Janine A

    2014-01-01

    The obesity epidemic has prompted researchers to find effective weight-loss and maintenance tools. Weight loss and subsequent maintenance are reliant on energy balance--the net difference between energy intake and energy expenditure. Negative energy balance, lower intake than expenditure, results in weight loss whereas positive energy balance, greater intake than expenditure, results in weight gain. Resistant starch has many attributes, which could promote weight loss and/or maintenance including reduced postprandial insulinemia, increased release of gut satiety peptides, increased fat oxidation, lower fat storage in adipocytes, and preservation of lean body mass. Retention of lean body mass during weight loss or maintenance would prevent the decrease in basal metabolic rate and, therefore, the decrease in total energy expenditure, that occurs with weight loss. In addition, the fiber-like properties of resistant starch may increase the thermic effect of food, thereby increasing total energy expenditure. Due to its ability to increase fat oxidation and reduce fat storage in adipocytes, resistant starch has recently been promoted in the popular press as a "weight loss wonder food". This review focuses on data describing the effects of resistant starch on body weight, energy intake, energy expenditure, and body composition to determine if there is sufficient evidence to warrant these claims.

  3. The effect of breakfast on appetite regulation, energy balance and exercise performance.

    PubMed

    Clayton, David J; James, Lewis J

    2016-08-01

    The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.

  4. 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.

  5. An update on Earth's energy balance in light of the latest global observations

    NASA Astrophysics Data System (ADS)

    Stephens, Graeme L.; Li, Juilin; Wild, Martin; Clayson, Carol Anne; Loeb, Norman; Kato, Seiji; L'Ecuyer, Tristan; Stackhouse, Paul W.; Lebsock, Matthew; Andrews, Timothy

    2012-10-01

    Climate change is governed by changes to the global energy balance. At the top of the atmosphere, this balance is monitored globally by satellite sensors that provide measurements of energy flowing to and from Earth. By contrast, observations at the surface are limited mostly to land areas. As a result, the global balance of energy fluxes within the atmosphere or at Earth's surface cannot be derived directly from measured fluxes, and is therefore uncertain. This lack of precise knowledge of surface energy fluxes profoundly affects our ability to understand how Earth's climate responds to increasing concentrations of greenhouse gases. In light of compilations of up-to-date surface and satellite data, the surface energy balance needs to be revised. Specifically, the longwave radiation received at the surface is estimated to be significantly larger, by between 10 and 17 Wm-2, than earlier model-based estimates. Moreover, the latest satellite observations of global precipitation indicate that more precipitation is generated than previously thought. This additional precipitation is sustained by more energy leaving the surface by evaporation -- that is, in the form of latent heat flux -- and thereby offsets much of the increase in longwave flux to the surface.

  6. Developmental programming of energy balance regulation: is physical activity more 'programmable' than food intake?

    PubMed

    Zhu, Shaoyu; Eclarinal, Jesse; Baker, Maria S; Li, Ge; Waterland, Robert A

    2016-02-01

    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 mechanisms underlying such developmental programming of energy balance are poorly understood, limiting our ability to intervene. Most studies of developmental programming of energy balance have focused on persistent alterations in the regulation of energy intake; energy expenditure has been relatively underemphasised. In particular, very few studies have evaluated developmental programming of physical activity. The aim of this review is to summarise recent evidence that early environment may have a profound impact on establishment of individual propensity for physical activity. Recently, we characterised two different mouse models of developmental programming of obesity; one models fetal growth restriction followed by catch-up growth, and the other models early postnatal overnutrition. In both studies, we observed alterations in body-weight regulation that persisted to adulthood, but no group differences in food intake. Rather, in both cases, programming of energy balance appeared to be due to persistent alterations in energy expenditure and spontaneous physical activity (SPA). These effects were stronger in female offspring. We are currently exploring the hypothesis that developmental programming of SPA occurs via induced sex-specific alterations in epigenetic regulation in the hypothalamus and other regions of the central nervous system. We will summarise the current progress towards testing this hypothesis. Early environmental influences on establishment of physical activity are likely an important factor in developmental programming of energy balance. Understanding the fundamental underlying mechanisms in appropriate animal models will help determine whether early life

  7. Verification Of Energy Balance In The Ansys V5.4 Thermal Calculations

    SciTech Connect

    H. Marr; M.J. Anderson

    2001-02-08

    The objective of this calculation is to verify the energy balance of the thermal calculations analyzed by ANSYS Version (V) 5.4 solver (see Section 4). The scope of this calculation is limited to calculating the energy balance of a two-dimensional repository thermal representation using the temperatures obtained from ANSYS V5.4. The procedure, AP-3.124, Calculations (Ref. 3), and the Technical Work Plan for: Waste Package Design Description for LA (Ref. 2) are used to develop this calculation. The associated activity is the development of engineering evaluations to support the Licensing Application design activities.

  8. 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.

  9. Bacterial proteostasis balances energy and chaperone utilization efficiently.

    PubMed

    Santra, Mantu; Farrell, Daniel W; Dill, Ken A

    2017-03-28

    Chaperones are protein complexes that help to fold and disaggregate a cell's proteins. It is not understood how four major chaperone systems of Escherichia coli work together in proteostasis: the recognition, sorting, folding, and disaggregating of the cell's many different proteins. Here, we model this machine. We combine extensive data on chaperoning, folding, and aggregation rates with expression levels of proteins and chaperones measured at different growth rates. We find that the proteostasis machine recognizes and sorts a client protein based on two biophysical properties of the client's misfolded state (M state): its stability and its kinetic accessibility from its unfolded state (U state). The machine is energy-efficient (the sickest proteins use the most ATP-expensive chaperones), comprehensive (it can handle any type of protein), and economical (the chaperone concentrations are just high enough to keep the whole proteome folded and disaggregated but no higher). The cell needs higher chaperone levels in two situations: fast growth (when protein production rates are high) and very slow growth (to mitigate the effects of protein degradation). This type of model complements experimental knowledge by showing how the various chaperones work together to achieve the broad folding and disaggregation needs of the cell.

  10. Bacterial proteostasis balances energy and chaperone utilization efficiently

    PubMed Central

    Santra, Mantu; Farrell, Daniel W.; Dill, Ken A.

    2017-01-01

    Chaperones are protein complexes that help to fold and disaggregate a cell’s proteins. It is not understood how four major chaperone systems of Escherichia coli work together in proteostasis: the recognition, sorting, folding, and disaggregating of the cell’s many different proteins. Here, we model this machine. We combine extensive data on chaperoning, folding, and aggregation rates with expression levels of proteins and chaperones measured at different growth rates. We find that the proteostasis machine recognizes and sorts a client protein based on two biophysical properties of the client’s misfolded state (M state): its stability and its kinetic accessibility from its unfolded state (U state). The machine is energy-efficient (the sickest proteins use the most ATP-expensive chaperones), comprehensive (it can handle any type of protein), and economical (the chaperone concentrations are just high enough to keep the whole proteome folded and disaggregated but no higher). The cell needs higher chaperone levels in two situations: fast growth (when protein production rates are high) and very slow growth (to mitigate the effects of protein degradation). This type of model complements experimental knowledge by showing how the various chaperones work together to achieve the broad folding and disaggregation needs of the cell. PMID:28292901

  11. 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.

  12. Validation of an Online Food Frequency Questionnaire against Doubly Labelled Water and 24 h Dietary Recalls in Pre-School Children

    PubMed Central

    Delisle Nyström, Christine; Henriksson, Hanna; Alexandrou, Christina; Bergström, Anna; Bonn, Stephanie; Bälter, Katarina; Löf, Marie

    2017-01-01

    The development of easy-to-use and accurate methods to assess the intake of energy, foods and nutrients in pre-school children is needed. KidMeal-Q is an online food frequency questionnaire developed for the LifeGene prospective cohort study in Sweden. The aims of this study were to compare: (i) energy intake (EI) obtained using KidMeal-Q to total energy expenditure (TEE) measured via doubly labelled water and (ii) the intake of certain foods measured using KidMeal-Q to intakes acquired by means of 24 h dietary recalls in 38 children aged 5.5 years. The mean EI calculated using KidMeal-Q was statistically different (p < 0.001) from TEE (4670 ± 1430 kJ/24 h and 6070 ± 690 kJ/24 h, respectively). Significant correlations were observed for vegetables, fruit juice and candy between KidMeal-Q and 24 h dietary recalls. Only sweetened beverage consumption was significantly different in mean intake (p < 0.001), as measured by KidMeal-Q and 24 h dietary recalls. In conclusion, KidMeal-Q had a relatively short answering time and comparative validity to other food frequency questionnaires. However, its accuracy needs to be improved before it can be used in studies in pre-school children. PMID:28098765

  13. Daily magnesium fluxes regulate cellular timekeeping and energy balance

    PubMed Central

    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

    2016-01-01

    Circadian clocks are fundamental to the biology of most eukaryotes, coordinating behavior and physiology to resonate with the environmental cycle of day and night through complex networks of clock-controlled genes1–3. A fundamental knowledge gap exists however, between circadian gene expression cycles and the biochemical mechanisms that ultimately facilitate circadian regulation of cell biology4,5. Here we report circadian rhythms in the intracellular concentration of magnesium ions, [Mg2+]i, which act as a cell-autonomous timekeeping component to determine key clock properties in both a human cell line and a unicellular alga that diverged from metazoans more than 1 billion years ago6. Given the essential role of Mg2+ as a cofactor for ATP, a functional consequence of [Mg2+]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 Mg2+ availability has potential to impact upon many of the cell’s >600 MgATP-dependent enzymes7 and every cellular system where MgNTP hydrolysis becomes rate limiting. Indeed, we find that circadian control of translation by mTOR8 is regulated through [Mg2+]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

  14. 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.

  15. 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.

  16. Energy balance in the watershed of Ipê, Northwestern São Paulo State, Brazil

    NASA Astrophysics Data System (ADS)

    Feitosa, Diego G.; T. Hernandez, Fernando B.; Franco, Renato A. M.; Teixeira, Antonio H. C.; Neale, Christopher M.

    2016-10-01

    The region of Ilha Solteira, in the Northwestern of São Paulo State, has been undergoing significant changes in agricultural land use and cover since 2006, as pasture fields have been replaced by sugarcane crop. This drastic change can lead to a disturbance in the energy balance, affecting the local climate. The aim of this paper was to assess some parameters related to the energy balance of Ipê's watershed, that changed since no sugarcane cultivation in 2006 to 2,164 hectares in 2011, occupying 31% of the catchment area with this important energy crop for the economy and the environment of Brazil. This study was carried out using remote sensing combined with weather data and using the SAFER (Simple Algorithm for Retrieving Evapotranspiration) model applied in 9 Landsat images collected between 2003 and 2011. The results showed a wide variation between the components of energy balance and when considering only the sugarcane crop were verified the increase values of ETa (Actual Evapotranspiration), H/Rn (Sensible Heat Flux/Net Radiation), TS (Surface Temperature), Rl↑ (Emitted longwave), Rl↓ (Incidente longwave) and surface albedo after the sugarcane production over these years. On the other hand, the NDVI, λE/Rn (Latent Heat Flux/Net Radiation) and Rn values (data) decreased in the same period. Also there was satisfactory correlation between NDVI and ETa. The SAFER model showed satisfactory results for studies of energy balance applied in the Northwestern of São Paulo State.

  17. Skeletal muscle responses to negative energy balance: effects of dietary protein.

    PubMed

    Carbone, John W; McClung, James P; Pasiakos, Stefan M

    2012-03-01

    Sustained periods of negative energy balance decrease body mass due to losses of both fat and skeletal muscle mass. Decreases in skeletal muscle mass are associated with a myriad of negative consequences, including suppressed basal metabolic rate, decreased protein turnover, decreased physical performance, and increased risk of injury. Decreases in skeletal muscle mass in response to negative energy balance are due to imbalanced rates of muscle protein synthesis and degradation. However, the underlying physiological mechanisms contributing to the loss of skeletal muscle during energy deprivation are not well described. Recent studies have demonstrated that consuming dietary protein at levels above the current recommended dietary allowance (0.8 g · kg(-1) · d(-1)) may attenuate the loss of skeletal muscle mass by affecting the intracellular regulation of muscle anabolism and proteolysis. However, the specific mechanism by which increased dietary protein spares skeletal muscle through enhanced molecular control of muscle protein metabolism has not been elucidated. This article reviews the available literature related to the effects of negative energy balance on skeletal muscle mass, highlighting investigations that assessed the influence of varying levels of dietary protein on skeletal muscle protein metabolism. Further, the molecular mechanisms that may contribute to the regulation of skeletal muscle mass in response to negative energy balance and alterations in dietary protein level are described.

  18. 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.

  19. 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

  20. 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.

  1. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    Introduction: 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.

  3. Energy and greenhouse gas balances for a solid waste incineration plant: a case study.

    PubMed

    Brinck, Kim; Poulsen, Tjalfe G; Skov, Henrik

    2011-10-01

    Energy and greenhouse gas balances for a waste incineration plant (Reno-Nord I/S, Aalborg, Denmark) as a function of time over a 45-year period beginning 1960 are presented. The quantity of energy recovered from the waste increased over time due to increasing waste production, increasing lower heating value of the waste and implementation of improved energy recovery technology at the incineration plant. Greenhouse gas (GHG) balances indicated progressively increasing GHG savings during the time period investigated as a result of the increasing energy production. The GHG balances show that the Reno-Nord incineration plant has changed from a net annual GHG emission of 30 kg CO(2)-eq person(-1) year(-1) to a net annual GHG saving of 770 kg CO(2)-eq person(-1) year(-1) which is equivalent to approximately 8% of the annual emission of GHG from an average Danish person (including emissions from industry and transport). The CO(2) emissions associated with combustion of the fossil carbon contained in the waste accounted for about two-thirds of the GHG turnover when no energy recovery is applied but its contribution reduces to between 10 and 15% when energy recovery is implemented. The reason being that energy recovery is associated with a large CO(2) saving (negative emission).

  4. Analysis of Short-Term Closure of the Surface Energy Balance in Different Seasons

    NASA Astrophysics Data System (ADS)

    Cava, D.; Contini, D.; Donateo, A.; Martano, P.

    2007-05-01

    A correct determination of the surface energy balance is an important quality test for measurements of turbulent surface fluxes. The energy balance is often not closed especially in non-homogeneous terrain or in presence of orographic obstacles. Daily energy budget is more easily balanced, because of the contribution of energy residuals of opposite sign; however short-term closure is rarely obtained. What distinguishes this study from previous ones is the effort to close short-term energy budget, and to explore the factors that mainly affect the energy imbalance during the day. To this aim we analysed data sets from southern Italy collected above a semiarid terrain during summer and fall seasons. Our analysis has shown that the global closure rate significantly improves after the correction for the error dependent on the ultrasonic anemometer angle of attack and for the error dependent on the heat storage into the soil. Furthermore a significant reduction of short-term energy residual results by taking into account the contribution to the transport by `large scale motions'. The obtained results are independent from the net incoming radiation.

  5. 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.

  6. Comparison of computational methods for estimation of energy balance of building envelopes

    NASA Astrophysics Data System (ADS)

    Kočí, Václav; Černý, Robert

    2013-10-01

    Two calculation methods of annual energy balance of building envelopes are presented in this paper. As reference building envelope, single-layer autoclaved aerated concrete masonry is chosen. The first calculation method is based on simplified standard procedure, the second method on results of more sophisticated hygrothermal simulation under realistic climatic conditions. Both results are compared and analyzed.

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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.

  12. 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.

  13. 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…

  14. Across-phase biomass pyrolysis stoichiometry, energy balance, and product formation kinetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predictive correlations between reactions occurring in the gas-, liquid- and solid-phases are necessary to economically utilize the thermochemical conversion of agricultural wastes impacting the food, water, and energy nexus. On the basis of an empirical mass balance (99.7%), this study established...

  15. 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.

  16. 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...

  17. 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…

  18. 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...

  19. Effect of dietary energy source on energy balance, production, metabolic disorders and reproduction in lactating dairy cattle.

    PubMed

    van Knegsel, Ariëtte T M; van den Brand, Henry; Dijkstra, Jan; Tamminga, Seerp; Kemp, Bas

    2005-01-01

    The pathway for oxidation of energy involves a balanced oxidation of C2 and C3 compounds. During early lactation in dairy cattle this C2/C3 ratio is out of balance, due to a high availability of lipogenic (C2) products and a low availability of glycogenic (C3) products relative of the C2 and C3 products required for milk production. This review compares studies which manipulated dietary energy source and shows that dietary energy source can affect the balance of the C2/C3 ratio, as indicated by plasma NEFA, beta-hydroxybutyrate (BHBA) and glucose levels. It is shown that glycogenic nutrients increase glucose and insulin concentrations and decrease NEFA and BHBA plasma levels. Extra lipogenic nutrients elevate NEFA and BHBA and decrease plasma glucose concentrations. Lipogenic nutrients generally increase milk fat percentage and decrease milk protein percentage, suggesting a surplus of C2 compounds. The inverse is the case for feeding extra glycogenic nutrients, implying reduced deamination and oxidation of glycogenic amino acids. Feeding extra glycogenic nutrients improved the energy balance (EB), in contrast to ambiguous results of lipogenic nutrients on EB. Moreover, glycogenic feed may reduce the severity of ketosis and fatty liver, but increased the incidence of (sub)clinical acidosis. Since studies are scarce, it seems difficult to draw conclusions on the effects of dietary energy source on reproduction. However, lipogenic nutrients decrease glucose and increase NEFA and BHBA plasma levels. High plasma NEFA and BHBA and low plasma glucose levels are associated with decreased reproductive performance, which might imply the C2/C3 compound balance to be important for reproductive function.

  20. Energy balance of a plasma with a wave, taking the wave nonpotentiality into account

    NASA Astrophysics Data System (ADS)

    Gelberg, M. G.; Volosevich, A. V.

    It is shown that the potential electric field of low-frequency plasma waves in the ionosphere is phase-shifted by approximately -pi/2 with respect to current fluctuations, while the vortex field is nearly cophase with the current. Thus, the work of energy transfer between the plasma and the wave occurs primarily with the participation of the vortex field. The wave nonpotentiality is shown to have a substantial effect on the energy balance of the wave-plasma system.

  1. 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.

    2013-12-01

    ⪉bel{sec:abstract} Snow surface temperature is a key control on energy exchanges at the snow surface, particularly net longwave radiation and turbulent energy fluxes. The snow surface temperature is in turn controlled by the balance between various external fluxes and the conductive heat flux, internal to the snowpack. 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 examine the parameterization of snow surface temperature in single layer snowmelt models from the perspective of heat conduction into a semi-infinite medium. We evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We also 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. These tests compare modeled and measured snow surface temperature, snow energy content, snow water equivalent, and snowmelt outflow. We found that with these refinements the model is able to better represent the snowpack energy balance and

  2. Acute metabolic responses to a 24-h ultra-marathon race in male amateur runners.

    PubMed

    Waśkiewicz, Zbigniew; Kłapcińska, Barbara; Sadowska-Krępa, Ewa; Czuba, Milosz; Kempa, Katarzyna; Kimsa, Elżbieta; Gerasimuk, Dagmara

    2012-05-01

    The study was conducted to evaluate the metabolic responses to a 24 h ultra-endurance race in male runners. Paired venous and capillary blood samples from 14 athletes (mean age 43.0 ± 10.8 years, body weight 64.3 ± 7.2 kg, VO(2max) 57.8 ± 6.1 ml kg(-1) min(-1)), taken 3 h before the run, after completing the marathon distance (42.195 km), after 12 h, and at the finish of the race, were analyzed for blood morphology, acid-base balance and electrolytes, lipid profile, interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and serum enzyme activities. Mean distance covered during the race was 168.5 ± 23.1 km (range 125.2-218.5 km). Prolonged ultra-endurance exercise triggered immune and inflammatory responses, as evidenced by a twofold increase in total leukocyte count with neutrophils and monocytes as main contributors, nearly 30-fold increase in serum IL-6 and over 20-fold rise in hsCRP. A progressive exponential increase in mean creatine kinase activity up to the level 70-fold higher than the respective pre-race value, a several fold rise in serum activities of aspartate aminotransferase and alanine aminotransferase, and a fairly stable serum γ-glutamyl transferase level, were indicative of muscle, but not of liver damage. With duration of exercise, there was a progressive development of hyperventilation-induced hypocapnic alkalosis, and a marked alteration in substrate utilization towards fat oxidation to maintain blood glucose homeostasis. The results of this study may imply that progressive decline in partial CO(2) pressure (hypocapnia) that develops during prolonged exercise may contribute to increased interleukin-6 production.

  3. 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.

  4. Effects of zonal flows on correlation between energy balance and energy conservation associated with nonlinear nonviscous atmospheric dynamics in a thin rotating spherical shell

    NASA Astrophysics Data System (ADS)

    Ibragimov, Ranis N.

    2016-12-01

    The nonlinear Euler equations are used to model two-dimensional atmosphere dynamics in a thin rotating spherical shell. The energy balance is deduced on the basis of two classes of functorially independent invariant solutions associated with the model. It it shown that the energy balance is exactly the conservation law for one class of the solutions whereas the second class of invariant solutions provides and asymptotic convergence of the energy balance to the conservation law.

  5. 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

  6. Radiative cooling to deep sub-freezing temperatures through a 24-h day–night cycle

    PubMed Central

    Chen, Zhen; Zhu, Linxiao; Raman, Aaswath; Fan, Shanhui

    2016-01-01

    Radiative cooling technology utilizes the atmospheric transparency window (8–13 μm) to passively dissipate heat from Earth into outer space (3 K). This technology has attracted broad interests from both fundamental sciences and real world applications, ranging from passive building cooling, renewable energy harvesting and passive refrigeration in arid regions. However, the temperature reduction experimentally demonstrated, thus far, has been relatively modest. Here we theoretically show that ultra-large temperature reduction for as much as 60 °C from ambient is achievable by using a selective thermal emitter and by eliminating parasitic thermal load, and experimentally demonstrate a temperature reduction that far exceeds previous works. In a populous area at sea level, we have achieved an average temperature reduction of 37 °C from the ambient air temperature through a 24-h day–night cycle, with a maximal reduction of 42 °C that occurs when the experimental set-up enclosing the emitter is exposed to peak solar irradiance. PMID:27959339

  7. 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.

  8. Radiative cooling to deep sub-freezing temperatures through a 24-h day-night cycle

    NASA Astrophysics Data System (ADS)

    Chen, Zhen; Zhu, Linxiao; Raman, Aaswath; Fan, Shanhui

    2016-12-01

    Radiative cooling technology utilizes the atmospheric transparency window (8-13 μm) to passively dissipate heat from Earth into outer space (3 K). This technology has attracted broad interests from both fundamental sciences and real world applications, ranging from passive building cooling, renewable energy harvesting and passive refrigeration in arid regions. However, the temperature reduction experimentally demonstrated, thus far, has been relatively modest. Here we theoretically show that ultra-large temperature reduction for as much as 60 °C from ambient is achievable by using a selective thermal emitter and by eliminating parasitic thermal load, and experimentally demonstrate a temperature reduction that far exceeds previous works. In a populous area at sea level, we have achieved an average temperature reduction of 37 °C from the ambient air temperature through a 24-h day-night cycle, with a maximal reduction of 42 °C that occurs when the experimental set-up enclosing the emitter is exposed to peak solar irradiance.

  9. Radiative cooling to deep sub-freezing temperatures through a 24-h day-night cycle.

    PubMed

    Chen, Zhen; Zhu, Linxiao; Raman, Aaswath; Fan, Shanhui

    2016-12-13

    Radiative cooling technology utilizes the atmospheric transparency window (8-13 μm) to passively dissipate heat from Earth into outer space (3 K). This technology has attracted broad interests from both fundamental sciences and real world applications, ranging from passive building cooling, renewable energy harvesting and passive refrigeration in arid regions. However, the temperature reduction experimentally demonstrated, thus far, has been relatively modest. Here we theoretically show that ultra-large temperature reduction for as much as 60 °C from ambient is achievable by using a selective thermal emitter and by eliminating parasitic thermal load, and experimentally demonstrate a temperature reduction that far exceeds previous works. In a populous area at sea level, we have achieved an average temperature reduction of 37 °C from the ambient air temperature through a 24-h day-night cycle, with a maximal reduction of 42 °C that occurs when the experimental set-up enclosing the emitter is exposed to peak solar irradiance.

  10. 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

  11. On increasing network lifetime in body area networks using global routing with energy consumption balancing.

    PubMed

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

    2012-09-26

    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.

  12. 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).

  13. Nicotine induces negative energy balance through hypothalamic AMP-activated protein kinase.

    PubMed

    Martínez de Morentin, Pablo B; Whittle, Andrew J; Fernø, Johan; Nogueiras, Rubén; Diéguez, Carlos; Vidal-Puig, Antonio; López, Miguel

    2012-04-01

    Smokers around the world commonly report increased body weight after smoking cessation as a major factor that interferes with their attempts to quit. Numerous controlled studies in both humans and rodents have reported that nicotine exerts a marked anorectic action. The effects of nicotine on energy homeostasis have been mostly pinpointed in the central nervous system, but the molecular mechanisms controlling its action are still not fully understood. The aim of this study was to investigate the effect of nicotine on hypothalamic AMP-activated protein kinase (AMPK) and its effect on energy balance. Here we demonstrate that nicotine-induced weight loss is associated with inactivation of hypothalamic AMPK, decreased orexigenic signaling in the hypothalamus, increased energy expenditure as a result of increased locomotor activity, increased thermogenesis in brown adipose tissue (BAT), and alterations in fuel substrate utilization. Conversely, nicotine withdrawal or genetic activation of hypothalamic AMPK in the ventromedial nucleus of the hypothalamus reversed nicotine-induced negative energy balance. Overall these data demonstrate that the effects of nicotine on energy balance involve specific modulation of the hypothalamic AMPK-BAT axis. These targets may be relevant for the development of new therapies for human obesity.

  14. Effects of continuous positive airway pressure on energy balance regulation: a systematic review

    PubMed Central

    Shechter, Ari

    2016-01-01

    Obesity is both a cause and a possible consequence of obstructive sleep apnoea (OSA), as OSA seems to affect parameters involved in energy balance regulation, including food intake, hormonal regulation of hunger/satiety, energy metabolism and physical activity. It is known that weight loss improves OSA, yet it remains unclear why continuous positive airway pressure (CPAP) often results in weight gain. The goal of this systematic review is to explore if and how CPAP affects the behaviour and/or metabolism involved in regulating energy balance. CPAP appears to correct for a hormonal profile characterised by abnormally high leptin and ghrelin levels in OSA, by reducing the circulating levels of each. This is expected to reduce excess food intake. However, reliable measures of food intake are lacking, and not yet sufficient to make conclusions. Although studies are limited and inconsistent, CPAP may alter energy metabolism, with reports of reductions in resting metabolic rate or sleeping metabolic rate. CPAP appears to not have an appreciable effect on altering physical activity levels. More work is needed to characterise how CPAP affects energy balance regulation. It is clear that promoting CPAP in conjunction with other weight loss approaches should be used to encourage optimal outcomes in OSA patients. PMID:27824596

  15. Energy balance and body composition during US Army special forces training.

    PubMed

    Margolis, Lee M; Rood, Jennifer; Champagne, Catherine; Young, Andrew J; Castellani, John W

    2013-04-01

    Small Unit Tactics (SUT) is a 64-day phase of the Special Forces Qualification Course designed to simulate real-world combat operations. Assessing the metabolic and physiological responses of such intense training allows greater insights into nutritional requirements of soldiers during combat. The purpose of this study was to examine energy balance around specific training events, as well as changes in body mass and composition. Data were collected from 4 groups of soldiers (n = 36) across 10-day periods. Participants were 28 ± 5 years old, 177 ± 6 cm tall, and weighed 83 ± 7 kg. Doubly labeled water (D2(18)O) was used to assess energy expenditure. Energy intake was calculated by subtracting energy in uneaten foods from known energy in distributed foods in individually packaged combat rations or in the dining facility. Body composition was estimated from skinfold thickness measurements on days 0 and 64 of the course. Simulated urban combat elicited that largest energy deficit (11.3 ± 2.3 MJ·day(-1) (2700 ± 550 kcal·day(-1)); p < 0.05), and reduction in body mass (3.3 ± 1.9 kg; p < 0.05), during SUT, while energy balance was maintained during weapons familiarization training and platoon size raids. Over the entire course body mass decreased by 4.2 ± 3.7 kg (p < 0.01), with fat mass decreasing by 2.8 ± 2.0 kg (p < 0.01) and fat-free mass decreasing by 1.4 ± 2.8 kg (p < 0.05). The overall reduction in body mass suggests that soldiers were in a negative energy balance during SUT, with high energy deficit being observed during strenuous field training.

  16. Influence of intense physical activity on energy balance and body fatness.

    PubMed

    Tremblay, A; Doucet, E

    1999-02-01

    The reduced contribution of physical activity to daily energy expenditure and the accessibility to high-fat foods have put an excessive burden on energy balance, resulting in an increase in the prevalence of obesity throughout the world. In this context, fat gain can be seen as a natural adaptation to deal with a fattening lifestyle, since the hormonal adaptations that accompany fat gain favour the readjustment of energy expenditure to energy intake. Intense physical activity would also seem to facilitate the regulation of energy balance, since it increases the energy cost of exercise, increases post-exercise energy expenditure and the potential of skeletal muscles to utilize lipids, and also favours a decrease in post-exercise intake. Moreover, the effects of intense exercise seem to be mediated by an activation of sympathetic nervous system activity that seems to be specific to skeletal muscle. It is also important to manipulate macronutrient composition in order to reduce fat intake, because unhealthy food habits can favour overfeeding and thus overcome the energy deficit caused by regular physical activity. Under free-living conditions, the combination of vigorous activity and healthy food practices can amount to a substantial weight loss which is comparable with that of other non-surgical approaches to treat obesity.

  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. 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...

  19. Including the effects of debris cover in a distributed glacier energy balance model (Invited)

    NASA Astrophysics Data System (ADS)

    Pellicciotti, F.; Reid, T.; Carenzo, M.; Brock, B. W.

    2010-12-01

    Distributed models of glacier energy balance, which make use of digital elevation models and extensive spatial data on local meteorology, have become very useful tools for predicting glacial ablation and runoff in recent years. They generally function by running a one-dimensional energy balance model at every point on a grid on the glacier surface - for each point in the grid the ablation is calculated based on the balance of heat fluxes at the ice-air boundary. However, one key component has been missing from distributed models to date, namely the effects of debris cover. Many glacier ablation zones are mantled in near-continuous blankets of rock debris, and debris-covered glaciers are important drivers of the water cycle in the European Alps, Andes and Himalayas. Moreover, debris covers have been seen to expand in recent years, so it is essential to assess exactly how the presence of debris may affect a glacier’s surface energy balance and potential responses to climate changes. The effects of a debris cover are complicated by the varying surface roughness, albedo and thermal properties of the debris in question, but generally a debris cover reduces glacier melt rate by insulating the glacier surface from direct solar radiation. Even on glaciers where the debris cover is not continuous, isolated patches of debris caused by rockfalls can affect the glacier evolution by introducing differential ablation across the glacier surface, thus creating ice-cored moraines that may persist after ‘clean’ parts of the glacier have wasted away. This paper presents the results of incorporating a one-dimensional ‘debris energy balance model’ called DEB-Model (Reid and Brock 2010) into a distributed melt model for Haut Glacier d’Arolla, Switzerland. DEB-Model numerically estimates debris surface temperature by considering the balance of heat fluxes at the air-debris interface, then calculates heat conduction through the debris in order to estimate melt rates at the

  20. Long-term mass- and energy balance of Kongsvegen glacier, Spitzbergen

    NASA Astrophysics Data System (ADS)

    Krismer, Thomas; Obleitner, Friedrich; Kohler, Jack

    2010-05-01

    We present meteorological and glaciological data from the equilibrium line (ELA) of Kongsvegen glacier (550masl) in Svalbard, covering the period 2000 until 2008. Mean annual air temperatures for the period range from -6.9 to -10.1°C and specific net annual mass balances range from -670 to +281 mm w eq. During some years substantial superimposed ice was formed and even survived the summer. The meteorological data were homogenized and used for input and validation of mass- and energy-balance simulations. The meteorological regime at the ELA is characterized by a coreless winter and summer temperatures around 0°C. Wind conditions are largely determined by katabatic winds and topgraphically channeled upper-air winds. Net short-wave radiation is determined by cloudiness during the polar day and by the seasonal evolution of glacier surface albedo. Long-wave radiation fluxes withdraw energy throughout the year and the mean annual net radiation is almost negligible. The turbulent sensible heat fluxes constitute a comparatively strong and continuous source of energy. The latent heat flux is characterized by prevailing condensation during winter and evaporation during summer. On average, however, the turbulent fluxes provide only a small amount of heat to the glacier. Most of the energy available from the atmosphere is used for summer melt and a small amount goes into heating the near surface ice layers. Similar investigations were performed at the tongue of the glacier (170masl) for a shorter period. Here the conditions are characterized by enhanced input from the atmospheric fluxes and correspondingly increased melt rates. In addition, accumulation is usually small (>50 cm snow) and melt can also occur during winter. We then investigate whether spatially distributed mass balance can be simulated using data measured outside of the glacier. Regression models were developed to derive model input from climate data measured at a nearby research station. These models are

  1. 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.

  2. Effects of fatty acid supplements on milk yield and energy balance of lactating dairy cows.

    PubMed

    Harvatine, K J; Allen, M S

    2006-03-01

    Saturated and unsaturated fatty acid supplements (FS) were evaluated for effects on yield of milk and milk components, concentration of milk components including milk fatty acid profile, and energy balance. Eight ruminally and duodenally cannulated cows and 8 noncannulated cows were used in a replicated 4 x 4 Latin square design experiment with 21-d periods. Treatments were control and a linear substitution of 2.5% fatty acids from saturated FS (SAT; prilled, hydrogenated free fatty acids) for partially unsaturated FS (UNS; calcium soaps of long-chain fatty acids). The SAT treatment did not change milk fat concentration, but UNS linearly decreased milk fat in cannulated cows and tended to decrease milk fat in noncannulated cows compared with control. Milk fat depression with UNS corresponded to increased concentrations of trans-10, cis-12 conjugated linoleic acid and trans C18:1 fatty acids in milk. Milk fat profile was similar for SAT and control, but UNS decreased concentration of short- and medium-chain FA. Digestible energy intake tended to decrease linearly with increasing unsaturated FS in cannulated and noncannulated cows. Increasing unsaturated FS linearly increased empty body weight and net energy gain in cannulated cows, whereas increasing saturated FS linearly increased plasma insulin. Efficiency of conversion of digestible energy to milk tended to decrease linearly with increasing unsaturated FS for cannulated cows only. Addition of SAT provided little benefit to production and energy balance, whereas UNS decreased energy intake and milk energy yield.

  3. 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.

  4. Surface energy balance measurements over a banana plantation in South China

    NASA Astrophysics Data System (ADS)

    Ding, Zhangwei; Wen, Zhiping; Wu, Renguang; Li, Zhenchao; Zhu, Jianjun; Li, Weibiao; Jian, Maoqiu

    2013-10-01

    The land surface energy exchange depends highly on the surface properties. Little is known of the energy balance over a typical banana plantation of humid tropics. In this study, we examine the characteristics of surface energy exchange over a typical banana field in South China during the period of May 2010 to April 2011 by using the eddy covariance and micrometeorological tower. The results showed that the diurnal and seasonal variations in surface latent heat flux were larger compared with those over the nearby grassland. The dominant energy partitioning varies with season. The latent heat flux was the main consumer of net radiation in summer, whereas the sensible heat flux was the main consumer in winter. The increasing cloud coverage and rain appear to control the surface energy balance with the development of the monsoon. Due to increased afternoon convective cloud systems in the monsoon active period, downward shortwave radiation was dramatically diminished around 14:00 pm. The annual mean Bowen ratio was 0.69, which fell within the range of other vegetated surfaces. The observed surface energy components were not closed, and the ratio of turbulent fluxes to the available energy was about 77 % in October-January and about 85 % in the other months after considering soil heat and air heat storage.

  5. 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...

  6. Energy balance in the semiarid area of the Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Liang, Jiening; Zhang, Lei; Cao, Xianjie; Wen, Jun; Wang, Jiemin; Wang, Guoyin

    2017-02-01

    To understand the energy balance over the complex terrain of the Loess Plateau, we analyzed data from the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL). From 1 June to 15 August 2008, the energy balance closure ratio ranged from 0.52 to 0.90 during the daytime when the available energy was greater than 150 W m-2; during nocturnal hours, it was about 0.25. We proposed a method based on water mass conservation to estimate the energy transmitted by the vertical movement of moisture in the soil and set out to explain the imbalance. During the daytime, the heat stored in the soil above the heat flux plate placed at 5 cm below the surface, the energy transmitted by the vertical movement of moisture in the soil, and the energy assimilated by plant photosynthesis contributed to 29.6%, 2.0%, and 1.8% of the energy residual, respectively. During stable conditions, the soil heat storage contributed to 46.4% of the energy residual, whereas the other energy terms contributed little. The instantaneous energy closure ratio was about 0.80 during unstable conditions; it was about 0.40 when the wind speed U was greater than 3.0 m s-1, while depends systematically on U under condition of U < 3.0 m s-1 during stable conditions. Under the weak wind stable condition, affected by topography-induced nonstationary motions, the turbulence is anisotropic with a strong horizontal fluctuation and a weak vertical fluctuation, resulting in weakened heat mixing in the vertical direction and stronger unclosure of energy.

  7. Surface energy balance of subarctic lowland palsa mires related to permafrost degradation

    NASA Astrophysics Data System (ADS)

    Stiegler, C.; Lindroth, A.; Johansson, M.

    2013-12-01

    During the last decades, an accelerating trend in increasing active-layer thickness and rising permafrost temperatures has been observed in the Nordic area. One region, where permafrost is particularly vulnerable to any further climate change is the Torneträsk area in northern subarctic Sweden. Within the next decades a projected ongoing climate warming and increase in snow cover will most likely lead to the disappearance of lowland permafrost in this region, affecting surface vegetation cover, greenhouse gas emissions and surface energy balance. In this study we link first results of surface energy balance measurements from lowland palsa mires in the Torneträsk region to the current state of permafrost and the degradation of peat plateaus. The study area covers several mires with similar local topographic conditions along an east-west oriented transect. Due to a strong climatic gradient, with maritime climate in the west and a more continental climate in the east, active layer thickness and permafrost temperatures generally increase from east to west while permafrost thickness decreases. In the recent years permafrost has fully disappeared at our westernmost study site while at the other investigated locations the peat plateaus show varying stages of degradation. For our measurements of energy balance components we use both a mobile energy balance tower and a stationary eddy covariance tower. Data has been collected during the growing season in 2013 by measuring all components of the surface energy budget, i.e. net radiation, turbulent fluxes of sensible and latent heat as well as ground heat fluxes. In addition, we measure active layer thickness and both soil moisture and soil temperature at various depths. First results display that the turbulent fluxes of latent heat exceed the fluxes of sensible heat at all investigated sites. The difference is more pronounced at those mires where permafrost degradation is at an advanced stage and therefore more open water

  8. 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

  9. 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.

  10. Sensor fault diagnosis based on energy balance evaluation: application to a metal processing.

    PubMed

    Theilliol, D; Noura, H; Sauter, D; Hamelin, F

    2006-10-01

    This paper deals with the design of a residual generator for fault detection and isolation in the dynamic closed-loop systems based on the balance of energy which "enters" and "leaves" plants. The main contribution of this paper consists in developing a suitable fault detection and isolation technique to detect faults in single-input single-output closed-loop system based on major signals without the requirement of an accurate static or dynamic model. Indeed, in the absence of conventional input-output models, the proposed method involves the on-line energy balance evaluation to detect a sensor fault. The application to the monitoring of a galvanizing line in steel industry shows the effectiveness of the suggested approach when a sensor fault occurs.

  11. Use of evapotranspiration model based on energy balance in the Ebinur Lake Wetland Nature Reserve

    NASA Astrophysics Data System (ADS)

    Shi, Qingsan; Shi, Qingdong; Wang, Zhi; Gao, Wei; Chang, Shunli

    2009-06-01

    An evapotranspiration model based on the energy balance for different vegetation types in arid area was built in the study, and applied to the natural ecological system of Lake Ebinur wetland nature reserve in Xinjiang. The spatial-temporal dynamic change of the vegetation evapotranspiration in the study area was computed, and the evapotranspiration of three typical vegetations was analyzed and compared. The ground meteorological data were used to test the model. The results show that the evapotranspiration of all the natural system is about 10mm/d, and the maximum is over 20mm/d and occurs between May and August. The evapotranspiration of three typical arid vegetations was estimated in sequence of Populus euphratica Oliv. Tamarix chinensis Lour. Haloxylon ammodendron (Meye)Bge. Finally, it is suggested that the ground surface vegetation types and arid characteristics are most important in the establishment of the evapotranspiration model of natural ecological system based on energy balance in arid areas.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

    2015-12-22

    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.

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

    PubMed

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

    2014-12-01

    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.

  2. 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.

  3. Energy balance, a new paradigm and methodological issues: the ANIBES study in Spain.

    PubMed

    Varela Moreiras, Gregorio; Ávila, José Manuel; Ruiz, Emma

    2015-02-26

    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 as key tools to solve the common problems to precisely quantify energy consumption and expenditure at population level. Within this context, the increasing complexity of the diet, but also the common problems of under and over reporting in nutrition surveys have to be taken into account. The overall purpose of the ANIBES ("Anthropometry, Intake and Energy Balance in Spain") Study was to carry out an accurate updating of foods and beverages intake, dietary habits/ behaviour and anthropometric data of the Spanish population as well as the energy expenditure and physical activity patterns, by the use of new tested instruments (i.e. tablet device to assess energy intake and accelerometer to evaluate physical activity). This new ANIBES Study will contribute to a better knowledge of the different key factors contributing to EB in Spain.

  4. Characterization of adult ghrelin and ghrelin receptor knockout mice under positive and negative energy balance.

    PubMed

    Sun, Yuxiang; Butte, Nancy F; Garcia, Jose M; Smith, Roy G

    2008-02-01

    Ghrelin and the ghrelin receptor (GH secretagogue receptor, GHS-R), are believed to have important roles in energy homeostasis. We describe results from the first studies to be conducted in congenic (N10) adult ghrelin(-/-) and Ghsr(-/-) mice under conditions of both positive (high-fat diet) and negative (caloric restriction) energy balance. In contrast to results from young N2 mutant mice, changes in body weight and energy expenditure are not clearly distinguishable across genotypes. Although respiratory quotient was lower in mice fed a high-fat diet, no differences were evident between littermate wild-type and null genotypes. With normal chow, a modest decrease trend in respiratory quotient was detected in ghrelin(-/-) mice but not in Ghsr(-/-) mice. Under caloric restriction, the weight loss of ghrelin(-/-) and Ghsr(-/-) mice was identical to wild-type littermates, but blood glucose levels were significantly lower. We conclude that adult congenic ghrelin(-/-) and Ghsr(-/-) mice are not resistant to diet-induced obesity but under conditions of negative energy balance show impairment in maintaining glucose homeostasis. These results support our hypothesis that the primary metabolic function of ghrelin in adult mice is to modulate glucose sensing and insulin sensitivity, rather than directly regulate energy intake and energy expenditure.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Consequences of inadequate food energy and negative energy balance in humans.

    PubMed

    Kurpad, A V; Muthayya, S; Vaz, M

    2005-10-01

    Energy deficiency is probably best measured in adults by the body mass index (BMI). Acute energy deficiency (AED) is associated with body weight loss, along with changes in body composition, as well as a reduced BMR and physical activity. Chronic energy deficiency (CED) is an inadequacy in food to which individuals adapt, at some cost. Individuals with this have never 'lost' weight: they have simply grown less. They adapt to the decreased food energy by reductions in their total energy expenditure (TEE), linked mainly to a lower body size, and to their physical activity. It seems unlikely that enhanced metabolic efficiency contributes substantially to energy saving in CED. Supplementation of energy deficient individuals is accompanied by significant fat deposition; this may have deleterious consequences. Women in many developing countries achieve a successful outcome to pregnancy in spite of being chronically undernourished. Reductions in basal metabolism and behavioural changes in the form of diminished physical activity could meet most of the extra energy needed for pregnancy. Milk energy output is maintained within the expected range in undernourished lactating mothers. Energy deficiency in children is best measured by height-for-age for stunting, and weight-for-height for wasting. Deficits in behavioural and functional parameters in children exist with undernutrition, and can be reduced by early nutritional supplementation along with the appropriate environment.

  16. Surface energy balance sensitivity to meteorological variability on Haig Glacier, Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Samaneh; Marshall, Shawn J.

    2016-11-01

    Energy exchanges between the atmosphere and the glacier surface control the net energy available for snow and ice melt. This paper explores the response of a midlatitude glacier in the Canadian Rocky Mountains to daily and interannual variations in the meteorological parameters that govern the surface energy balance. We use an energy balance model to run sensitivity tests to perturbations in temperature, specific humidity, wind speed, incoming shortwave radiation, glacier surface albedo, and winter snowpack depth. Variables are perturbed (i) in isolation, (ii) including internal feedbacks, and (iii) with co-evolution of meteorological perturbations, derived from the North American regional climate reanalysis (NARR) over the period 1979-2014. Summer melt at this site has the strongest sensitivity to interannual variations in temperature, albedo, and specific humidity, while fluctuations in cloud cover, wind speed, and winter snowpack depth have less influence. Feedbacks to temperature forcing, in particular summer albedo evolution, double the melt sensitivity to a temperature change. When meteorological perturbations covary through the NARR forcing, summer temperature anomalies remain important in driving interannual summer energy balance and melt variability, but they are reduced in importance relative to an isolated temperature forcing. Covariation of other variables (e.g., clear skies, giving reduced incoming longwave radiation) may be partially compensating for the increase in temperature. The methods introduced in this paper provide a framework that can be extended to compare the sensitivity of glaciers in different climate regimes, e.g., polar, maritime, or tropical environments, and to assess the importance of different meteorological parameters in different regions.

  17. 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

  18. 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

  19. Progress and challenges in the estimation of the global energy balance

    NASA Astrophysics Data System (ADS)

    Wild, Martin

    2017-02-01

    While enormous progress in the determination of the global energy fluxes in and out of the climate system was made in the past decades due to the installation of sophisticated space-born observation systems, substantial discrepancies remained in the estimated and simulated surface energy budgets, as they cannot be directly measured from space. The increasing availability of accurate surface observations, improvements in the satellite retrievals of surface fluxes and model advancement, however, lead to a recent convergence of independent estimates on some of the global mean surface energy balance components to within a few Wm-2. This suggests that we are approaching a stage where we are not only confident in the magnitudes of the global annual mean energy balance components at the TOA, but increasingly also at the surface. Consensus emerges on a global mean surface downward shortwave flux near 185 Wm-2, as well as global mean surface downward and upward longwave fluxes slightly above 340 Wm-2 and below 400 Wm-2, respectively. Taking into account remaining uncertainties in the surface albedo, this implies a surface absorbed shortwave radiation near or somewhat above 160 Wm-2, which leaves an atmospheric shortwave absorption of nearly 80 Wm-2, considering a total shortwave absorption of 240 Wm-2 in the global climate system. Thus, 2/3 of the absorption of shortwave radiation in the climate system takes place at the surface, 1/3 in the atmosphere. Given the above estimates, the global mean surface net radiation (surface radiation balance) appears to be around 105 Wm-2. The partitioning of this radiative energy at the Earth's surface into sensible and latent heat is only weekly constrained by direct observations and is still afflicted with considerable uncertainties. The best estimate of global mean surface net radiation near 105 Wm-2 promoted here should, however, enable a consistent representation of the magnitudes of the global energy and water cycles within their

  20. 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

  1. 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.

  2. [Effects of RFRP-3 on reproductive function and energy balance in mammals].

    PubMed

    Xiang, Wei; Lai, Ping; Zhang, Bao-Yun; Wang, Ping-Qing; Chu, Ming-Xing; Fan, Qi; Liu, Chong-Xu; Tan, Ying

    2012-08-01

    The hypothalamo-pituitary-gonadal (HPG) axis integrates internal and external cues via a balance of stimulatory and inhibitory neurochemical systems to regulate reproductive function in mammals. However, RFRP-3 is a unique inhibitor of HPG axis at the hypothalamuic level in mammals to date. A large number of previous studies have confirmed that RFamide-related peptide (RFRP-3) suppresses gonadotropin-releasing hormone (GnRH) system and luteinizing hormone (LH) secretion, thereby affecting the reproduction. However, whether the inhibition of LH secretion by RFRP-3 occurs at the pituitary level or the hypothalamus level is not clear. It is interesting that RFRP-3 is also related to signal pathway of melatonin modulating mammal seasonal reproduction, but little is known about the effects of melatonin on the RFRP-3 neuron up to now. In addition, RFRP-3 also plays an important role in the regulation of energy balance and behavior. The regulatory mechanism of RFRP-3 in HPG axis and role of RFRP-3 in modulating mammalian energy balance, as well as behavior, are systematically elaborated and the remaining unsolved problems are also discussed in this paper.

  3. 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

  4. 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

  5. Sex-related differences in energy balance in response to caloric restriction.

    PubMed

    Valle, A; Català-Niell, A; Colom, B; García-Palmer, F J; Oliver, J; Roca, P

    2005-07-01

    Sex-related differences in energy balance were studied in young Wistar rats fed standard chow pellets either ad libitum or in restricted amounts (60% of ad libitum intake) for 100 days. Caloric intake, indirect calorimetry, organ and adipose tissue weights, energy efficiency, liver mitochondrial respiration rate, and brown adipose tissue (BAT) uncoupling protein-1 (UCP1) content were measured. Ad libitum-fed females showed greater oxygen consumption (Vo(2)) and carbon dioxide production (Vco(2)) and lower energy efficiency than males. Caloric restriction induced a chronic drop of Vo(2) and Vco(2) in females but not in males over the period studied. Restricted females showed a better conservation of metabolic active organ mass and a greater decrease in adipose depots than restricted males. Moreover, changes of BAT size and UCP1 content suggest that BAT may be the main cause responsible for sex differences in the response of energy balance to caloric restriction. In conclusion, our results indicate that females under caloric restriction conditions deactivate facultative thermogenesis to a greater degree than males. This ability may have obvious advantages for female survival and therefore the survival of the species when food is limiting.

  6. Energy and greenhouse balance of photocatalytic CO2 conversion to methanol

    NASA Astrophysics Data System (ADS)

    Haumann, D.; Goettlicher, G.; Muench, W.

    2012-10-01

    Within the Leading-Edge Cluster "Forum Organic Electronic", the research project "Solar2Fuel" funded by the German Ministry of education and research (BMBF) (2009 - 2012), EnBW, BASF, Karlsruhe Institute of Technology and Ruprecht-Karls-University of Heidelberg aim to develop a future solar powered CO2 to methanol conversion technology. CO2 from stationary sources such as power plants shall be catalytically converted together with water to a product such as methanol by use of solar irradiation. For this purpose a catalyst shall be developed. EnBW investigates the required boundary conditions to make such a principle interesting with respect to energy and greenhouse gas balance as well as economic evaluations. The assessment of boundary conditions includes the analysis of the whole chain from power generation, CO2 capture and transport, a virtual photocatalytic reactor, the product purification and use in the traffic sector. Most important technical factors of the process such as CO2 conversion efficiency is presented. CO2 capturing and liquefaction are the most energy intensive process steps, CO2 transport in pipeline is highly energy efficient and depending on energy need of the photoconversion step and the product purification, the overall greenhouse gas balance is comparable with the underground storage of the captured CO2.

  7. 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.

  8. [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.

  9. Temporal variability of the energy balance of thick arctic pack ice

    SciTech Connect

    Lindsay, R.W.

    1998-03-01

    The temporal variability of the six terms of the energy balance equation for a slab of ice 3 m thick is calculated based on 45 yr of surface meteorological observations from the drifting ice stations of the former Soviet Union. The equation includes net radiation, sensible heat flux, latent heat flux, bottom heat flux, heat storage, and energy available for melting. The energy balance is determined with a time-dependent 10-layer thermodynamic model of the ice slab that determines the surface temperature and the ice temperature profile using 3-h forcing values. The observations used for the forcing values are the 2-m air temperature, relative humidity and wind speed, the cloud fraction, the snow depth and density, and the albedo of the nonponded ice. The downwelling radiative fluxes are estimated with parameterizations based on the cloud cover, the air temperature and humidity, and the solar angle. The linear relationship between the air temperature and both the cloud fraction and the wind speed is also determined for each month of the year. The annual cycles of the mean values of the terms of the energy balance equation are all nearly equal to those calculated by others based on mean climatological forcing values. The short-term variability, from 3 h to 16 days, of both the forcings and the fluxes, in investigated on a seasonal basis with the discreet wavelet transform. Significant diurnal cycles are found in the net radiation, storage, and melt, but not in the sensible or latent heat fluxes. The total annual ice-melt averages 0.67 m, ranges between 0.29 and 1.09 m, and exhibits large variations from year to year. It is closely correlated with the albedo and, to a lesser extent, with the latitude and the length of the melt season. 29 refs., 14 figs., 3 tabs.

  10. Energy balance and food intake: the role of PPARgamma gene polymorphisms.

    PubMed

    Cecil, Joanne E; Watt, Peter; Palmer, Colin N; Hetherington, Marion

    2006-06-30

    Mechanisms regulating energy balance involve complex interactions between genetic, environmental and behavioural (learnt and intrinsic) factors. Genotype may drive the partitioning of energy metabolism and predispose to site-specific adiposity, culminating in a state of energy imbalance. One candidate gene with a direct link to adiposity is the peroxisome proliferator-activated receptor gamma (PPARG) gene. PPARG is a cell nuclear receptor expressed almost exclusively in adipose tissue that regulates adipocyte differentiation, lipid metabolism and insulin sensitivity. PPARgamma appears to be a key regulator of energy balance, with polymorphisms on the PPARG gene linked to obesity and effects on body composition. Our research has confirmed an association between the pro12ala allele and reduced incidence of obesity in pre-pubertal children and there are strong associations between genetic variation at the PPARG locus and percentage body fat. Moreover, our evidence suggests that PPARG C-681G and pro12ala polymorphisms display opposing effects in terms of growth phenotype, with pro12Ala associated with deficient energy utilisation, leading to reduced growth and the G-681 variant associated with accelerated growth compared with wildtypes. Common differences in this gene have also been associated with variations in body weight in response to dietary macronutrients. Preliminary evidence suggests that PPARG variants may even be involved in the control of short term energy compensation. Taken together these data suggest that the role of PPARG is varied and complex, influencing fat deposition and growth velocity early in life, with potential impact in the control of energy intake and appetite regulation, and could provide a key target for future research and anti-obesity agents.

  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. 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)

  14. NQRS Data for C24H20BK (Subst. No. 1576)

    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 C24H20BK (Subst. No. 1576)

  15. Probable maximum precipitation for 24 h duration over southeast Asian monsoon region—Selangor, Malaysia

    NASA Astrophysics Data System (ADS)

    Desa M, M. N.; Noriah, A. B.; Rakhecha, P. R.

    The probable maximum precipitation (PMP) for stations in Malaysia using Hershfield formula is routinely estimated as mean plus 15 standard deviations processed from yearly maximum rainfall values. The value of 15 as frequency factor is too high for a humid region such as Malaysia. In this paper, yearly maximum 1-day rainfall data of about 30-60 years for 33 stations in the region of Selangor, Malaysia, were analysed in an attempt to estimate PMP for 1-day duration based on an appropriate frequency factor for the first time. Based on the actual rainfall data of the stations, the highest value of this frequency factor was found to be 8.7. The frequency factor of 8.7 was subsequently used to estimate 24-h PMP values for the 33 stations. Using these PMP estimates, a generalised map was prepared showing the spatial distribution of 24-h PMP. It was found that 24-h PMP over Selangor, Malaysia, varied from 375 to 500 mm and the average ratio of the 24-h PMP to the highest observed 1-day rainfall was found to be about 2.0. The PMP map is considered as important to determine reliable and consistent PMP estimate for any location in Selangor, Malaysia, for designing costly and large hydraulic structures.

  16. 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

  17. 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...

  18. 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

  19. Rayleigh criterion and acoustic energy balance in unconfined self-sustained oscillating flames

    SciTech Connect

    Durox, D.; Schuller, T.; Noiray, N.; Birbaud, A.L.; Candel, S.

    2008-11-15

    Instabilities of confined combustion systems are often discussed in terms of the Rayleigh criterion, which provides a necessary condition for unstable operation and is commonly used to distinguish driving and damping regions. The analysis is also carried out in some cases by making use of an acoustic energy balance in which the Rayleigh term acts as a source. The case of unconfined flames is less well documented but of importance in practical systems used in heating and drying. This study is motivated by problems of self-sustained oscillations of radiant burners for domestic or industrial processes and of various other types of open flames. Application of the Rayleigh criterion and of the balance of acoustic energy to oscillations arising in such unconfined systems is examined. The objective is to see if the Rayleigh condition is fulfilled and to show how the different perturbed variables are linked to each other to develop an unstable oscillation. These issues are investigated by experiments in two geometries. The first case relates to a single ''V''- or ''M''-shaped flame formed by a burner behaving like a Helmholtz resonator. The second geometry features a collection of conical flames (CCF) established by a multipoint injector. This system is fed by a manifold that features a set of plane modes and resonates like an organ pipe at frequencies corresponding to odd multiples of the quarter wave. The Rayleigh criterion and a related result written in the form of an acoustic energy balance are used to define conditions of instability. A link is established between the pressure signal radiated by the burner and the total heat release rate perturbation yielding the phase lag between these two variables and providing conditions for unstable operation. Systematic experiments carried out in the two burner geometries and model predictions are in good agreement indicating that the Rayleigh source term is positive and that the criterion is well fulfilled by the wavefield

  20. Rayleigh criterion and acoustic energy balance in unconfined self-sustained oscillating flames

    SciTech Connect

    Durox, D.; Schuller, T.; Noiray, N.; Birbaud, A.L.; Candel, S.

    2009-01-15

    Instabilities of confined combustion systems are often discussed in terms of the Rayleigh criterion, which provides a necessary condition for unstable operation and is commonly used to distinguish driving and damping regions. The analysis is also carried out in some cases by making use of an acoustic energy balance in which the Rayleigh term acts as a source. The case of unconfined flames is less well documented but of importance in practical systems used in heating and drying. This study is motivated by problems of self-sustained oscillations of radiant burners for domestic or industrial processes and of various other types of open flames. Application of the Rayleigh criterion and of the balance of acoustic energy to oscillations arising in such unconfined systems is examined. The objective is to see if the Rayleigh condition is fulfilled and to show how the different perturbed variables are linked to each other to develop an unstable oscillation. These issues are investigated by experiments in two geometries. The first case relates to a single ''V''- or ''M''-shaped flame formed by a burner behaving like a Helmholtz resonator. The second geometry features a collection of conical flames (CCF) established by a multipoint injector. This system is fed by a manifold that features a set of plane modes and resonates like an organ pipe at frequencies corresponding to odd multiples of the quarter wave. The Rayleigh criterion and a related result written in the form of an acoustic energy balance are used to define conditions of instability. A link is established between the pressure signal radiated by the burner and the total heat release rate perturbation yielding the phase lag between these two variables and providing conditions for unstable operation. Systematic experiments carried out in the two burner geometries and model predictions are in good agreement indicating that the Rayleigh source term is positive and that the criterion is well fulfilled by the wavefield

  1. Meridional trends in the radiative energy balance of the Venus mesosphere

    NASA Astrophysics Data System (ADS)

    Lee, Y. J.; Titov, D.; Ignatiev, N.; Tellmann, S.; Paetzold, M.; Piccioni, G.

    2012-04-01

    The Venus clouds play an important role in the radiative energy balance. Thermal cooling to space occurs from the cloud tops. Also almost half of the solar energy received by Venus is deposited at about the same altitude by the unknown UV absorber. Observations revealed the latitudinal trend in the aerosol structure with cloud top altitude decreasing from ~68 km in low latitudes to ~62 km in polar region and aerosol scale height changing from ~4 km to ~1-2 km. This results in significant changes in the radiative energy balance at the cloud tops and the mesosphere as well as global energy balance of the planet. Here we present calculations of the thermal flux in the 0-99 km altitude range using the latitude dependent cloud top structure. Aerosol and temperature profiles are based on the radio science experiment (VeRa) and the thermal spectrometer (VIRTIS) onboard Venus Express [1]. We used radiative transfer model merged with a fast line-by-line routine to calculate thermal fluxes in the broad wavenumber range from 50 to 2590 cm-1 (=3.86-200.0 μm). The cloud layers are responsible for thermal cooling below ~70 km altitude. The meridional changes in the upper clouds result in cooling rate variation 6-10 K/day along the latitude. Contribution of the CO2 emission to the outgoing flux becomes dominant above 70 km altitude. The outgoing flux shows maxima at equator (164 W/m2) and pole (171 W/m2) and a minimum (133 W/m2) in the "cold collar" region (50-60° S). The earlier studies of the solar heating rate were used to derive a meridional trend of the radiative energy balance. The comparison shows dominant thermal cooling in high latitudes and strong solar heating at low latitudes suggesting radiative disequilibrium, that implies a need for another, possibly dynamical, mechanism to maintain the observed temperature and cloud structure [2,3].

  2. Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland.

    PubMed

    Lund, Magnus; Stiegler, Christian; Abermann, Jakob; Citterio, Michele; Hansen, Birger U; van As, Dirk

    2017-02-01

    The surface energy balance (SEB) is essential for understanding the coupled cryosphere-atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled with modelling efforts are essential for assessing the impact of warming in the Arctic.

  3. 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.

  4. 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

  5. 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.

  6. AMP-activated protein kinase and energy balance in breast cancer

    PubMed Central

    Zhao, Hong; Orhan, Yelda C; Zha, Xiaoming; Esencan, Ecem; Chatterton, Robert T; Bulun, Serdar E

    2017-01-01

    Cancer growth and metastasis depends on the availability of energy. Energy-sensing systems are critical in maintaining a balance between the energy supply and utilization of energy for tumor growth. A central regulator in this process is AMP-activated protein kinase (AMPK). In times of energy deficit, AMPK is allosterically modified by the binding of increased levels of AMP and ADP, making it a target of specific AMPK kinases (AMPKKs). AMPK signaling prompts cells to produce energy at the expense of growth and motility, opposing the actions of insulin and growth factors. Increasing AMPK activity may thus prevent the proliferation and metastasis of tumor cells. Activated AMPK also suppresses aromatase, which lowers estrogen formation and prevents breast cancer growth. Biguanides can be used to activate AMPK, but AMPK activity is modified by many different interacting factors; understanding these factors is important in order to control the abnormal growth processes that lead to breast cancer neoplasia. Fatty acids, estrogens, androgens, adipokines, and another energy sensor, sirtuin-1, alter the phosphorylation and activation of AMPK. Isoforms of AMPK differ among tissues and may serve specific functions. Targeting AMPK regulatory processes at points other than the upstream AMPKKs may provide additional approaches for prevention of breast cancer neoplasia, growth, and metastasis. PMID:28337254

  7. 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.

  8. Multivariate and univariate analysis of energy balance data from lactating dairy cows.

    PubMed

    Moraes, L E; Kebreab, E; Strathe, A B; Dijkstra, J; France, J; Casper, D P; Fadel, J G

    2015-06-01

    The objectives of the study were to develop a multivariate framework for analyzing energy balance data from lactating cows and investigate potential changes in maintenance requirements and partial efficiencies of energy utilization by lactating cows over the years. The proposed model accounted for the fact that metabolizable energy intake, milk energy output, and tissue energy balance are random variables that interact mutually. The model was specified through structural equations implemented in a Bayesian framework. The structural equations, along with a model traditionally used to estimate energetic parameters, were fitted to a large database of indirect calorimetry records from lactating cows. Maintenance requirements and partial efficiencies for both models were similar to values reported in the literature. In particular, the estimated parameters (with 95% credible interval in parentheses) for the proposed model were: net energy requirement for maintenance equal to 0.36 (0.34, 0.38) MJ/kg of metabolic body weight·day; the efficiency of utilizing dietary energy for milk production and tissue gain were 0.63 (0.61, 0.64) and 0.70 (0.68, 0.72), respectively; the efficiency of utilizing body stores for milk production was 0.89 (0.87, 0.91). Furthermore, additional analyses were conducted for which energetic parameters were allowed to depend on the decade in which studies were conducted. These models investigated potential changes in maintenance requirements and partial efficiencies over the years. Canonical correlation analysis was used to investigate the association between changes in energetic parameters with additional dietary and animal characteristics available in the database. For both models, net energy requirement for maintenance and the efficiency of utilizing dietary energy for milk production and tissue gain increased in the more recent decades, whereas the efficiency of utilizing body stores for milk production remained unchanged. The increase in

  9. Balance Food and Activity

    MedlinePlus

    ... eNewsletters Calendar Balance Food and Activity What is Energy Balance? Energy is another word for "calories." Your ... adults, fewer calories are needed at older ages. Energy Balance in Real Life Think of it as ...

  10. Effect of milking frequency and diet on milk production, energy balance, and reproduction in dairy cows.

    PubMed

    Patton, J; Kenny, D A; Mee, J F; O'Mara, F P; Wathes, D C; Cook, M; Murphy, J J

    2006-05-01

    The objective of this study was to determine the effects of reduced milking frequency and increased dietary energy density in early lactation on milk production, energy balance, and subsequent fertility. Sixty-six spring-calving, multiparous Holstein-Friesian cows were assigned to 1 of 3 treatment groups: once-daily milking on a standard diet (1xST); 3-times daily milking on a standard diet (3xST); and 3-times daily milking on a high-energy diet. Treatments were imposed for the first 28 d of lactation, after which all groups were milked twice daily and fed the standard diet. During the treatment period, the 1xST cows had 19.6% lower milk yield and higher milk fat and milk protein concentrations (15.7 and 10.2%, respectively) compared with 3xST. Dry matter (DM) intake was similar between 1xST and 3xST during the treatment period (12.64 vs. 13.25 kg/ d; SED = 0.82). Daily energy balance was less negative for 1xST compared with 3xST during wk 1 to 3 of lactation [-3.92 vs. -5.30 unité fourragère lait (UFL)/d; SED = 0.65; 1 UFL is equal to the net energy for lactation of 1 kg of standard air-dry barley]. During the treatment period, the cows on the high-energy diet had 17% higher milk yield, higher DM intake (15.5 vs. 13.9 kg/d; SED = 0.71), and similar energy balance (-4.45 vs. -4.35 UFL/d; SED = 0.65) compared to 3xST. Diet had no significant effect on any of the fertility variables measured. The interval to first ovulation was shorter for 1xST than 3xST (18.3d vs. 28.6d; SED = 1.76). In conclusion, once-daily milking in early lactation may promote earlier resumption of ovarian cyclicity, mediated through improved nutritional status.

  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. 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...

  13. Nutrient-sensing nuclear receptors PPARα and FXR control liver energy balance.

    PubMed

    Preidis, Geoffrey A; Kim, Kang Ho; Moore, David D

    2017-04-03

    The nuclear receptors PPARα (encoded by NR1C1) and farnesoid X receptor (FXR, encoded by NR1H4) are activated in the liver in the fasted and fed state, respectively. PPARα activation induces fatty acid oxidation, while FXR controls bile acid homeostasis, but both nuclear receptors also regulate numerous other metabolic pathways relevant to liver energy balance. Here we review evidence that they function coordinately to control key nutrient pathways, including fatty acid oxidation and gluconeogenesis in the fasted state and lipogenesis and glycolysis in the fed state. We have also recently reported that these receptors have mutually antagonistic impacts on autophagy, which is induced by PPARα but suppressed by FXR. Secretion of multiple blood proteins is a major drain on liver energy and nutrient resources, and we present preliminary evidence that the liver secretome may be directly suppressed by PPARα, but induced by FXR. Finally, previous studies demonstrated a striking deficiency in bile acid levels in malnourished mice that is consistent with results in malnourished children. We present evidence that hepatic targets of PPARα and FXR are dysregulated in chronic undernutrition. We conclude that PPARα and FXR function coordinately to integrate liver energy balance.

  14. 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.

  15. Energy balance model applied to pasture experimental areas in São Paulo State, Brazil

    NASA Astrophysics Data System (ADS)

    Bayma-Silva, Gustavo; de Castro Teixeira, Antonio Heriberto; de Castro Victoria, Daniel; Furlan Nogueira, Sandra; Freitas Leivas, Janice; Coaguila, Daniel N.; Rodrigues Herling, Valdo

    2016-10-01

    The Simple Algorithm for Evapotranspiration Retrieving (SAFER) was used to estimate biophysical parameters and the energy balance components in two different pasture experimental areas, in the São Paulo state, Brazil. The experimental pastures consist in six rotational (RGS) and three continuous grazing systems (CGS) paddocks. Landsat-8 images from 2013 and 2015 dry and rainy seasons were used, as these presented similar hydrological cycle, with 1,600 mm and 1,613 mm of annual precipitation, resulting in 19 cloud-free images. Bands 1 to 7 and thermal bands 10 and 11 were used with weather data from a station located near the experimental area. NDVI, biomass, evapotranspiration and latent heat flux (λE) temporal values statistically differ CGS from RGS areas. Grazing systems influences the energy partition and these results indicate that RGS benefits biomass production, evapotranspiration and the microclimate, due higher LE values. SAFER is a feasible tool to estimate biophysical parameters and energy balance components in pasture and has potential to discriminate continuous and rotation grazing systems in a temporal analysis.

  16. 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.

  17. 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.

  18. 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.

  19. A decade of changing surface energy balance components over a large water region

    NASA Astrophysics Data System (ADS)

    Petchprayoon, Pakorn; Blanken, Peter D.; Hussein, Khalid; Abdalati, Waleed; Lawavirotwong, Siam

    2016-10-01

    This study has investigated the physical processes of energy exchange between the water surface and atmosphere over Lake Huron. The four components of surface energy balance, including net radiation, latent heat, sensible heat, and heat storage, were estimated using the eleven years (2002-2012) daily MODIS data together with in-situ measurements. Good agreement was found between the seasonal turbulent heat fluxes calculated from satellite data and those from the direct measurements (eddy covariance method) with correlation coefficients of 0.94 and 0.95 for sensible heat and latent heat, respectively. There were temporal, spatial heterogeneities, and strong seasonal pattern for all of the four components, which were very high in summer and low in winter for net radiation and heat storage. In contrast, latent heat and sensible heat were very high in the winter and very low in the summer. Trend analysis revealed long term changes for each of the energy balance components, particularly the increase in latent heat which was equivalent to evaporation rate of 0.017 mm m-2 per year, indicating that lake evaporation increased by 0.19 mm m-2 over the eleven years observation period. This was possibly a result of a smaller amount of over lake ice cover and an increase in surface water temperature of Lake Huron.

  20. The endocannabinoid system as a link between homoeostatic and hedonic pathways involved in energy balance regulation.

    PubMed

    Di Marzo, V; Ligresti, A; Cristino, L

    2009-06-01

    The endocannabinoid system (ECS) and, in particular, cannabinoid CB(1) receptors, their endogenous agonists (the endocannabinoids anandamide and 2-arachidonoylglycerol) and enzymes for the biosynthesis and degradation of the latter mediators are emerging as key players in the control of all aspects of food intake and energy balance. The ECS is involved in stimulating both the homoeostatic (that is, the sensing of deficient energy balance and gastrointestinal load) and the hedonic (that is, the sensing of the salience and the incentive/motivational value of nutrients) aspects of food intake. The orexigenic effects of endocannabinoids are exerted in the brain by CB(1)-mediated stimulatory and inhibitory effects on hypothalamic orexigenic and anorectic neuropeptides, respectively; by facilitatory actions on dopamine release in the nucleus accumbens shell; and by regulating the activity of sensory and vagal fibres in brainstem-duodenum neural connections. In turn, the levels of anandamide and 2-arachidonoylglycerol and/or CB(1) receptors in the brain are under the control of leptin, ghrelin and glucocorticoids in the hypothalamus, under that of dopamine in the limbic forebrain and under that of cholecystokinin and ghrelin in the brainstem. These bi-directional communications between the ECS and other key players in energy balance ensure local mediators such as the endocannabinoids to act in a way coordinated in both 'space' and 'time' to enhance food intake, particularly after a few hours of food deprivation. Alterations of such communications are, however, also among the underlying causes of overactivity of the ECS in hyperphagia and obesity, a phenomenon that provided the rationale for the development of anti-obesity drugs from CB(1) receptor antagonists.

  1. Large and small-scale structures and the dust energy balance problem in spiral galaxies

    NASA Astrophysics Data System (ADS)

    Saftly, W.; Baes, M.; De Geyter, G.; Camps, P.; Renaud, F.; Guedes, J.; De Looze, I.

    2015-04-01

    The interstellar dust content in galaxies can be traced in extinction at optical wavelengths, or in emission in the far-infrared. Several studies have found that radiative transfer models that successfully explain the optical extinction in edge-on spiral galaxies generally underestimate the observed FIR/submm fluxes by a factor of about three. In order to investigate this so-called dust energy balance problem, we use two Milky Way-like galaxies produced by high-resolution hydrodynamical simulations. We create mock optical edge-on views of these simulated galaxies (using the radiative transfer code SKIRT), and we then fit the parameters of a basic spiral galaxy model to these images (using the fitting code FitSKIRT). The basic model includes smooth axisymmetric distributions along a Sérsic bulge and exponential disc for the stars, and a second exponential disc for the dust. We find that the dust mass recovered by the fitted models is about three times smaller than the known dust mass of the hydrodynamical input models. This factor is in agreement with previous energy balance studies of real edge-on spiral galaxies. On the other hand, fitting the same basic model to less complex input models (e.g. a smooth exponential disc with a spiral perturbation or with random clumps), does recover the dust mass of the input model almost perfectly. Thus it seems that the complex asymmetries and the inhomogeneous structure of real and hydrodynamically simulated galaxies are a lot more efficient at hiding dust than the rather contrived geometries in typical quasi-analytical models. This effect may help explain the discrepancy between the dust emission predicted by radiative transfer models and the observed emission in energy balance studies for edge-on spiral galaxies.

  2. 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.

  3. Evapotranspiration dynamics in a boreal peatland and its impact on the water and energy balance

    NASA Astrophysics Data System (ADS)

    Wu, Jiabing; Kutzbach, Lars; Jager, Daniel; Wille, Christian; Wilmking, Martin

    2010-12-01

    Hydrological conditions play a key role in the carbon cycle of northern peatlands. This study examines the evapotranspiration (ET) dynamics and its impact on the water and energy balance in response to differing meteorological conditions during the exceptionally dry year 2006 and the normal wet year 2007 at a boreal peatland in Finland. Energy and water vapor fluxes were determined continuously using the eddy covariance approach. Daily ET rates varied considerably during the growing season and averaged 2.23 ± 0.15 mm d-1 and 1.59 ± 0.07 mm d-1 in the dry and wet year, respectively. Synoptic weather conditions as reflected by incoming radiation and water vapor pressure deficit (VPD) were the key factors controlling ET. Differences in the precipitation patterns and summer temperature also accounted for some of the observed differences in ET between the 2 years. No evidence was found for a relationship between ET rates and water table level, probably due to the relatively high water table level even in the dry year. Latent heat flux dominated the energy balance, particularly in the dry year 2006 with 60% of cumulative precipitation returned to the atmosphere through ET. In the wet year 2007, runoff dominated the water loss, and only 36% of the cumulative precipitation was returned to the atmosphere through ET. While the annual water balance regime of the peatland was mainly regulated by the precipitation pattern, daily measured ET was closely related to potential evaporation, and latent heat flux could be well modeled by the Penman-Monteith approach, suggesting two feasible schemes for ET prediction in peatlands under well watered conditions.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Obesity therapy: altering the energy intake-and-expenditure balance sheet.

    PubMed

    Crowley, Vivion E F; Yeo, Giles S H; O'Rahilly, Stephen

    2002-04-01

    Obesity is associated with numerous health complications, which range from non-fatal debilitating conditions such as osteoarthritis, to life-threatening chronic diseases such as coronary heart disease, diabetes and certain cancers. The psychological consequences of obesity can range from lowered self-esteem to clinical depression. Despite the high prevalence of obesity and the many advances in our understanding of how it develops, current therapies have persistently failed to achieve long-term success. This review focuses on how fat mass can be reduced by altering the balance between energy intake and expenditure.

  9. The seasonal CO2 cycle on Mars - An application of an energy balance climate model

    NASA Technical Reports Server (NTRS)

    James, P. B.; North, G. R.

    1982-01-01

    Energy balance climate models of the Budyko-Sellers variety are applied to the carbon-dioxide cycle on Mars. Recent data available from the Viking mission, in particular the seasonal pressure variations measured by Viking landers, are used to constrain the models. No set of parameters was found for which a one-dimensional model parameterized in terms of ground temperature gave an adequate fit to the observed pressure variations. A modified, two-dimensional model including the effects of dust storms and the polar hood reasonably reproduces the pressure curve, however. The implications of these results for Martian climate changes are discussed.

  10. On energy balance and the structure of radiated waves in kinetics of crystalline defects

    NASA Astrophysics Data System (ADS)

    Sharma, Basant Lal

    2016-11-01

    Traveling waves, with well-known closed form expressions, in the context of the defects kinetics in crystals are excavated further with respect to their inherent structure of oscillatory components. These are associated with, so called, Frenkel-Kontorova model with a piecewise quadratic substrate potential, corresponding to the symmetric as well as asymmetric energy wells of the substrate, displacive phase transitions in bistable chains, and brittle fracture in triangular lattice strips under mode III conditions. The paper demonstrates that the power expended theorem holds so that the sum of rate of working and the rate of total energy flux into a control strip moving steadily with the defect equals the rate of energy sinking into the defect, in the sense of N.F. Mott. In the conservative case of the Frenkel-Kontorova model with asymmetric energy wells, this leads to an alternative expression for the mobility in terms of the energy flux through radiated lattice waves. An application of the same to the case of martensitic phase boundary and a crack, propagating uniformly in bistable chains and triangular lattice strips, respectively, is also provided and the energy release is expressed in terms of the radiated energy flux directly. The equivalence between the well-known expressions and their alternative is established via an elementary identity, which is stated and proved in the paper as the zero lemma. An intimate connection between the three distinct types of defects is, thus, revealed in the framework of energy balance, via a structural similarity between the corresponding variants of the 'zero' lemma containing the information about radiated energy flux. An extension to the dissipative models, in the presence of linear viscous damping, is detailed and analog of the zero lemma is proved. The analysis is relevant to the dynamics of dislocations, brittle cracks, and martensitic phase boundaries, besides possible applications to analogous physical contexts which are

  11. 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.

  12. 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.

  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. 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.

  15. Energy utilization, nitrogen balance and microbial protein supply in cattle fed Pennisetum purpureum and condensed tannins.

    PubMed

    Piñeiro-Vázquez, A T; Canul-Solis, J R; Alayón-Gamboa, J A; Chay-Canul, A J; Ayala-Burgos, A J; Solorio-Sánchez, F J; Aguilar-Pérez, C F; Ku-Vera, J C

    2017-02-01

    The aim of the experiment was to assess the effect of condensed tannins (CT) on feed intake, dry matter digestibility, nitrogen balance, supply of microbial protein to the small intestine and energy utilization in cattle fed a basal ration of Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight of 295 ± 19 kg were allotted to five treatments consisting of increasing levels of CT (0, 1, 2, 3 and 4% CT/kg DM) in a 5 × 5 Latin square design. Dry matter intake (DMI) was similar (p > 0.05) between treatments containing 0, 1, 2 and 3% of CT/kg DM and it was reduced (p < 0.05) to 4% CT (5.71 kg DM/day) with respect to that observed with 0% CT (6.65 kg DM/day). Nitrogen balance, purine derivatives excretion in urine, microbial protein synthesis and efficiency of synthesis of microbial nitrogen in the rumen were not affected (p ≥ 0.05) by the increase in the levels of condensed tannins in the ration. Energy loss as CH4 was on average 2.7% of the gross energy consumed daily. Metabolizable energy intake was 49.06 MJ/day in cattle fed low-quality tropical grass with a DMI of 6.27 kg/day. It is concluded that concentrations of CT between 2 and 3% of DM of ration reduced energy loss as CH4 by 31.3% and 47.6%, respectively, without affecting intakes of dry and organic matter; however, digestibilities of dry and organic matter are negatively affected.

  16. Pharmacological interventions in the newborn piglet in the first 24 h after hypoxia-ischemia. A hemodynamic and electrophysiological perspective.

    PubMed

    Peeters-Scholte, Cacha; van den Tweel, Evelyn; Ioroi, Tomoaki; Post, Ilka; Braun, Kees; Veldhuis, Wouter; Nicolay, Klaas; Groenendaal, Floris; van Bel, Frank

    2002-11-01

    The purpose of this study was to investigate whether combined inhibition of neuronal and inducible nitric oxide synthase (NOS) by 2-iminobiotin, free radical scavenging by allopurinol, and non-protein-bound iron chelation with deferoxamine improved cerebral oxygenation, electrocortical brain activity, and brain energy status during the first 24 h after hypoxia-ischemia (HI) in the newborn piglet. Forty-three newborn piglets were subjected to 1 h of severe HI by occluding both carotid arteries and phosphorous magnetic resonance spectroscopy ((31)P-MRS)-guided hypoxia, whereas five served as sham-operated controls. Upon reperfusion, piglets received vehicle (n=12), 2-iminobiotin (n=11), allopurinol (n=10), or deferoxamine (n=10). Cerebral oxygenation was recorded with near-infrared spectrophotometry (NIRS), electrocortical brain activity was assessed with amplitude-integrated EEG (aEEG), and cerebral energy status with (31)P-MRS. The oxygenated hemoglobin (HbO(2)) and total hemoglobin (tHb) were significantly increased in vehicle-treated piglets compared with 2-iminobiotin-treated and deferoxamine-treated piglets. No change in deoxygenated Hb (HHb) was demonstrated over time. The aEEG was significantly preserved in 2-iminobiotin- and deferoxamine-treated piglets compared with vehicle-treated piglets. Allopurinol treatment was not as effective as 2-iminobiotin treatment after HI. Phosphocreatine/inorganic phosphate ratios (PCr/P(i)) were significantly decreased for vehicle-treated piglets at 24 h post-HI, whereas 2-iminobiotin, allopurinol, and deferoxamine prevented the development of secondary energy failure. We speculate that the beneficial effects, especially of 2-iminobiotin, but also of deferoxamine, are due to reduced peroxynitrite-mediated oxidation.

  17. 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.

  18. 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.

  19. 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.

  20. Energy balance in disk and CO2 laser beam inert gas fusion cutting

    NASA Astrophysics Data System (ADS)

    Scintilla, Leonardo Daniele; Tricarico, Luigi; Wetzig, Andreas; Beyer, Eckhard

    2012-03-01

    Experimental, numerical and analytical investigations were performed to give a possible explanation of the differences in cutting quality detected for inert gas laser beam cutting process performed with disk and CO2 laser sources. Cutting experiments were carried out at maximum cutting speed on cold work steel test specimens with different sheet thicknesses. The particular feature of the applied experimental setup was the similar geometry of both the CO2 and the disk laser beam with comparable values of the focus diameter and the Rayleigh length. The thermodynamic analysis was based on experimentally primary losses evaluation by means of polymethylmethacrylate (PMMA) blocks, on numerical computation of conductive power losses and analytical calculation of the remaining terms of energy balance. Energy balance allowed the evaluation of secondary losses and proportion of vaporized kerf volume used for justifying the lower quality of disk laser cuts. The lower proportion of vaporized kerf volume detected for disk laser cuts results in an increased process temperature, thus an increase of viscosity of molten material and the subsequent more difficult ejection of the melted material from the cut kerf.

  1. 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

  2. Ghrelin-Reactive Immunoglobulins in Conditions of Altered Appetite and Energy Balance

    PubMed Central

    Fetissov, Sergueï O.; Lucas, Nicolas; Legrand, Romain

    2017-01-01

    Part of circulating ghrelin is bound to immunoglobulins (Ig) protecting it from degradation and preserving its functional activity. This review summarizes the data on ghrelin- and desacyl-ghrelin-reactive IgG in conditions of altered appetite and energy balance. Plasma levels and affinity kinetics of such IgG were compared in patients with obesity and anorexia nervosa (AN) and in animal models of obesity including ob/ob mice, high-fat diet-induced obese mice, and obese Zucker rats as well as in mice after chronic food restriction and activity-based anorexia and in rats with methotrexate-induced anorexia. We show that plasmatic IgG in both obese humans and animals are characterized by increased affinity for ghrelin. In contrast, patients with AN and anorectic rodents all show lower affinity of ghrelin- and desacyl-ghrelin-reactive IgG, respectively, the changes which were not observed in non-anorectic, chronically starved mice. We also show that affinity of ghrelin-reactive IgG correlate with plasma levels of ghrelin. These data point to common mechanisms underlying modifications of affinity kinetics properties of ghrelin-reactive IgG during chronic alterations of energy balance in humans and rodents and support a functional role of such autoantibodies in ghrelin-mediated regulation of appetite. PMID:28191004

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Alternatives to linear analysis of energy balance data from lactating dairy cows.

    PubMed

    Kebreab, E; France, J; Agnew, R E; Yan, T; Dhanoa, M S; Dijkstra, J; Beever, D E; Reynolds, C K

    2003-09-01

    The current energy requirements system used in the United Kingdom for lactating dairy cows utilizes key parameters such as metabolizable energy intake (MEI) at maintenance (MEm), the efficiency of utilization of MEI for 1) maintenance, 2) milk production (kl), 3) growth (kg), and the efficiency of utilization of body stores for milk production (kt). Traditionally, these have been determined using linear regression methods to analyze energy balance data from calorimetry experiments. Many studies have highlighted a number of concerns over current energy feeding systems particularly in relation to these key parameters, and the linear models used for analyzing. Therefore, a database containing 652 dairy cow observations was assembled from calorimetry studies in the United Kingdom. Five functions for analyzing energy balance data were considered: straight line, two diminishing returns functions, (the Mitscherlich and the rectangular hyperbola), and two sigmoidal functions (the logistic and the Gompertz). Meta-analysis of the data was conducted to estimate kg and kt. Values of 0.83 to 0.86 and 0.66 to 0.69 were obtained for kg and kt using all the functions (with standard errors of 0.028 and 0.027), respectively, which were considerably different from previous reports of 0.60 to 0.75 for kg and 0.82 to 0.84 for kt. Using the estimated values of kg and kt, the data were corrected to allow for body tissue changes. Based on the definition of kl as the derivative of the ratio of milk energy derived from MEI to MEI directed towards milk production, MEm and kl were determined. Meta-analysis of the pooled data showed that the average kl ranged from 0.50 to 0.58 and MEm ranged between 0.34 and 0.64 MJ/kg of BW0.75 per day. Although the constrained Mitscherlich fitted the data as good as the straight line, more observations at high energy intakes (above 2.4 MJ/kg of BW0.75 per day) are required to determine conclusively whether milk energy is related to MEI linearly or not.

  9. 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

  10. Role of stearoyl-CoA desaturase-1 in skin integrity and whole body energy balance.

    PubMed

    Sampath, Harini; Ntambi, James M

    2014-01-31

    The skin is the single largest organ in humans, serving as a major barrier to infection, water loss, and abrasion. The functional diversity of skin requires the synthesis of large amounts of lipids, such as triglycerides, wax esters, squalene, ceramides, free cholesterol, free fatty acids, and cholesterol and retinyl esters. Some of these lipids are used as cell membrane components, signaling molecules, and a source of energy. An important class of lipid metabolism enzymes expressed in skin is the Δ(9)-desaturases, which catalyze the synthesis in Δ(9)-monounsaturated lipids, primarily oleoyl-CoA (18:1n-9) and palmitoyl-CoA (16:1n-7), the major monounsaturated fatty acids in cutaneous lipids. Mice with a deletion of the Δ(9)-desaturase-1 isoform (SCD1) either globally (Scd1(-/-)) or specifically in the skin (skin-specific Scd1-knockout; SKO) present with marked changes in cutaneous lipids and skin integrity. Interestingly, these mice also exhibit increased whole body energy expenditure, protection against diet-induced adiposity, hepatic steatosis, and glucose intolerance. The increased energy expenditure in skin-specific Scd1-knockout (SKO) mice is a surprising phenotype, as it links cutaneous lipid homeostasis with whole body energy balance. This minireview summarizes the role of skin SCD1 in regulating skin integrity and whole body energy homeostasis and offers a discussion of potential pathways that may connect these seemingly disparate phenotypes.

  11. 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.

  12. 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.

  13. 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.

  14. 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).

  15. 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.

  16. The roles of melanin-concentrating hormone in energy balance and reproductive function: Are they connected?

    PubMed

    Naufahu, Jane; Cunliffe, Adam D; Murray, Joanne F

    2013-01-01

    Melanin-concentrating hormone (MCH) is an anabolic neuropeptide with multiple and diverse physiological functions including a key role in energy homoeostasis. Rodent studies have shown that the ablation of functional MCH results in a lean phenotype, increased energy expenditure and resistance to diet-induced obesity. These findings have generated interest among pharmaceutical companies vigilant for potential anti-obesity agents. Nutritional status affects reproductive physiology and behaviours, thereby optimising reproductive success and the ability to meet energetic demands. This complex control system entails the integration of direct or indirect peripheral stimuli with central effector systems and involves numerous mediators. A role for MCH in the reproductive axis has emerged, giving rise to the premise that MCH may serve as an integratory mediator between those discrete systems that regulate energy balance and reproductive function. Hence, this review focuses on published evidence concerning i) the role of MCH in energy homoeostasis and ii) the regulatory role of MCH in the reproductive axis. The question as to whether the MCH system mediates the integration of energy homoeostasis with the neuroendocrine reproductive axis and, if so, by what means has received limited coverage in the literature; evidence to date and current theories are summarised herein.

  17. Sustainable conversion of agriculture wastes into activated carbons: energy balance and arsenic removal from water.

    PubMed

    Dieme, M M; Villot, A; Gerente, C; Andres, Y; Diop, S N; Diawara, C K

    2017-02-01

    The aims of this study are to investigate the production of activated carbons (AC) from Senegal agricultural wastes such as cashew shells, millet stalks and rice husks and to implement them in adsorption processes devoted to arsenic (V) removal. AC were produced by a direct physical activation with water steam without other chemicals. This production of AC has also led to co-products (gas and bio-oil) which have been characterized in terms of physical, chemical and thermodynamical properties for energy recovery. Considering the arsenic adsorption results and the energy balance for the three studied biomasses, the first results have shown that the millet stalks seem to be more interesting for arsenate removal from natural water and an energy recovery with a GEEelec of 18.9%. Cashew shells, which have shown the best energy recovery (34.3%), are not suitable for arsenate removal. This global approach is original and contributes to a recycling of biowastes with a joint recovery of energy and material.

  18. Balancing energy development and conservation: a method utilizing species distribution models.

    PubMed

    Jarnevich, Catherine S; Laubhan, Murray K

    2011-05-01

    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.

  19. Autonomic nervous system in the control of energy balance and body weight: personal contributions.

    PubMed

    Messina, G; De Luca, V; Viggiano, An; Ascione, A; Iannaccone, T; Chieffi, S; Monda, M

    2013-01-01

    The prevalence of obesity is increasing in the industrialized world, so that the World Health Organization considers obesity as a "pandemia" in rich populations. The autonomic nervous system plays a crucial role in the control of energy balance and body weight. This review summarizes our own data and perspectives, emphasizing the influence exerted by autonomic nervous system on energy expenditure and food intake, which are able to determine the body weight. Activation of the sympathetic discharge causes an increase in energy expenditure and a decrease in food intake, while reduction of food intake and body weight loss determines a reduction of the sympathetic activity. On the other hand, pathophysiological mechanisms of the obesity involve alterations of the sympathetic nervous system in accordance with the "Mona Lisa Hypothesis," an acronym for "most obesities known are low in sympathetic activity." Furthermore, the parasympathetic influences on the energy expenditure are analyzed in this review, showing that an increase in parasympathetic activity can induce a paradoxical enhancement of energy consumption.

  20. 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)

  1. Nqrs Data for C24H22Cl2Cu2N6 (Subst. No. 1582)

    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 C24H22Cl2Cu2N6 (Subst. No. 1582)

  2. Ambulant 24-h glucose rhythms mark calendar and biological age in apparently healthy individuals.

    PubMed

    Wijsman, Carolien A; van Heemst, Diana; Hoogeveen, Evelien S; Slagboom, P Eline; Maier, Andrea B; de Craen, Anton J M; van der Ouderaa, Frans; Pijl, Hanno; Westendorp, Rudi G J; Mooijaart, Simon P

    2013-04-01

    Glucose metabolism marks health and disease and is causally inferred in the aging process. Ambulant continuous glucose monitoring provides 24-h glucose rhythms under daily life conditions. We aimed to describe ambulant 24-h glucose rhythms measured under daily life condition in relation to calendar and biological age in apparently healthy individuals. In the general population and families with propensity for longevity, we studied parameters from 24-h glucose rhythms; glucose levels; and its variability, obtained by continuous glucose monitoring. Participants were 21 young (aged 22-37 years), 37 middle-aged (aged 44-72 years) individuals from the general population, and 26 middle-aged (aged 52-74 years) individuals with propensity for longevity. All were free of diabetes. Compared with young individuals, middle-aged individuals from the general population had higher mean glucose levels (5.3 vs. 4.7 mmol L(-1) , P < 0.001), both diurnally (P < 0.001) and nocturnally (P = 0.002). Glucose variability was higher in the middle-aged compared with the young (standard deviation 0.70 vs. 0.57 mmol L(-1) , P = 0.025). Compared with middle-aged individuals from the general population, middle-aged individuals with propensity for longevity had lower overall mean glucose levels (5.2 vs. 5.4 mmol L(-1) , P = 0.047), which were more different nocturnally (4.8 vs. 5.2 mmol L(-1) , P = 0.003) than diurnally (5.3 vs. 5.5 mmol L(-1) , P = 0.14). There were no differences in glucose variability between these groups. Results were independent of body mass index. Among individuals without diabetes, we observed significantly different 24-h glucose rhythms depending on calendar and biological age.

  3. 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)

  4. 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.

  5. 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

  6. Transcriptomic response of Arabidopsis thaliana after 24 h incubation with the biocontrol fungus Trichoderma harzianum.

    PubMed

    Morán-Diez, Eugenia; Rubio, Belén; Domínguez, Sara; Hermosa, Rosa; Monte, Enrique; Nicolás, Carlos

    2012-04-15

    Trichoderma harzianum is a fungus used as biocontrol agent using its antagonistic abilities against phytopathogenic fungi, although it has also direct effects on plants, increasing or accelerating their growth and resistance to diseases and the tolerance to abiotic stresses. We analyzed Arabidopsis thaliana gene expression changes after 24 h of incubation in the presence of T. harzianum T34 using the Affymetrix GeneChip Arabidopsis ATH1. Because this microarray contains more than 22,500 probe sets representing approximately 24,000 genes, we were able to construct a global picture of the molecular physiology of the plant at 24 h of T. harzianum-Arabidopsis interaction. We identified several differentially expressed genes that are involved in plant responses to stress, regulation of transcription, signal transduction or plant metabolism. Our data support the hypothesis that salicylic acid- and jasmonic acid-related genes were down-regulated in A. thaliana after 24 h of incubation in the presence of T. harzianum T34, while several genes related to abiotic stress responses were up-regulated. These systemic changes elicited by T. harzianum in Arabidopsis are discussed.

  7. Availability of 24-h urine collection method on dietary phosphorus intake estimation

    PubMed Central

    Sakuma, Masae; Morimoto, Yuuka; Suzuki, Yukie; Suzuki, Akitsu; Noda, Saaya; Nishino, Kanaho; Ando, Sakiko; Ishikawa, Makoto; Arai, Hidekazu

    2017-01-01

    Accurate assessment of dietary phosphorus intake is necessary to prevent hyperphosphatemia. The aim of this study was to evaluate the 24-h urine collection method for estimation of phosphate intake in healthy males. Two experiments, a 1-day and a 5-day loading test, were performed. After an overnight fast, subjects consumed test meals, 24-h urine collection was performed, and blood samples were obtained. In the 5-day loading test, a phosphorus supplement was orally administered on day 3. The association between the phosphorus content of test meals and urinary excretion, anthropometric indices, and blood biomarkers was analyzed to develop a more precise formula for estimating phosphorus intake. In the 1-day loading test, the standard deviation of predictive phosphorus intake, based on multiple linear regression analysis, was less than that for the phosphorus absorption rate. In the 5-day loading test, urinary phosphorus excretion was similar on days 2, 4 and 5, but was significantly higher on day 3 after phosphorus supplementation. Our results indicate that estimation of dietary phosphorus intake with the 24-h urine collection method, using the amount of phosphorus and urea nitrogen excretion, may increase the precision of short-term monitoring. PMID:28366992

  8. Effect of octreotide on 24-h blood pressure profile in acromegaly.

    PubMed

    Fallo, F; Barzon, L; Boscaro, M; Casiglia, E; Sonino, N

    1998-05-01

    The aim of the study was to investigate the effect of octreotide, a somatostatin analog drug potentially able to inhibit growth hormone (GH), on the circadian blood pressure profile in a group of patients with acromegaly. Ten patients with GH-secreting pituitary adenoma were studied before and 6 months after treatment with subcutaneous octreotide 0.2 to 0.6 mg/day. Twenty-four hour blood pressure and heart rate were measured every 15 min at daytime (07:00 to 22:59) and every 30 min at nighttime (23:00 to 06:59) using a TM-2420 recorder. No correlation was found between GH levels and 24-h blood pressure in baseline conditions. Untreated patients had a significant nocturnal decrease of both systolic and diastolic blood pressure (P < .01), and all showed a circadian systolic or diastolic blood pressure rhythm. During octreotide treatment, 24 h as well as nighttime systolic and diastolic blood pressures significantly increased (P < .05), whereas daytime systolic and diastolic blood pressures did not change. Treated patients did not have a nocturnal decline in both systolic and diastolic blood pressures (P = NS), and eight lost their systolic or diastolic blood pressure rhythm. In conclusion, blood pressure circadian rhythm seems to be maintained in acromegaly. Octreotide treatment is associated with an increase of 24-h and nighttime blood pressure, and with loss of circadian blood pressure rhythm. Splanchnic vasoconstriction by this drug, shifting blood to peripheral vessels, may explain this phenomenon.

  9. 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.

  10. 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

  11. 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

  12. Tropical Ocean Surface Energy Balance Variability: Linking Weather to Climate Scales

    NASA Technical Reports Server (NTRS)

    Roberts, J. Brent; Clayson, Carol Anne

    2013-01-01

    Radiative and turbulent surface exchanges of heat and moisture across the atmosphere-ocean interface are fundamental components of the Earth s energy and water balance. Characterizing the spatiotemporal variability of these exchanges of heat and moisture is critical to understanding the global water and energy cycle variations, quantifying atmosphere-ocean feedbacks, and improving model predictability. These fluxes are integral components to tropical ocean-atmosphere variability; they can drive ocean mixed layer variations and modify the atmospheric boundary layer properties including moist static stability, thereby influencing larger-scale tropical dynamics. Non-parametric cluster-based classification of atmospheric and ocean surface properties has shown an ability to identify coherent weather regimes, each typically associated with similar properties and processes. Using satellite-based observational radiative and turbulent energy flux products, this study investigates the relationship between these weather states and surface energy processes within the context of tropical climate variability. Investigations of surface energy variations accompanying intraseasonal and interannual tropical variability often use composite-based analyses of the mean quantities of interest. Here, a similar compositing technique is employed, but the focus is on the distribution of the heat and moisture fluxes within their weather regimes. Are the observed changes in surface energy components dominated by changes in the frequency of the weather regimes or through changes in the associated fluxes within those regimes? It is this question that the presented work intends to address. The distribution of the surface heat and moisture fluxes is evaluated for both normal and non-normal states. By examining both phases of the climatic oscillations, the symmetry of energy and water cycle responses are considered.

  13. 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.

  14. The dust energy balance in the edge-on spiral galaxy NGC 4565

    NASA Astrophysics Data System (ADS)

    De Looze, Ilse; Baes, Maarten; Bendo, George J.; Ciesla, Laure; Cortese, Luca; de Geyter, Gert; Groves, Brent; Boquien, Médéric; Boselli, Alessandro; Brondeel, Lena; Cooray, Asantha; Eales, Steve; Fritz, Jacopo; Galliano, Frédéric; Gentile, Gianfranco; Gordon, Karl D.; Hony, Sacha; Law, Ka-Hei; Madden, Suzanne C.; Sauvage, Marc; Smith, Matthew W. L.; Spinoglio, Luigi; Verstappen, Joris

    2012-12-01

    We combine new dust continuum observations of the edge-on spiral galaxy NGC 4565 in all Herschel/Spectral and Photometric Imaging Receiver (250, 350 and 500 μm) wavebands, obtained as part of the Herschel Reference Survey, and a large set of ancillary data (Spitzer, Sloan Digital Sky Survey, Galaxy Evolution Explorer) to analyse its dust energy balance. We fit a radiative transfer model for the stars and dust to the optical maps with the fitting algorithm FITSKIRT. To account for the observed ultraviolet and mid-infrared emission, this initial model was supplemented with both obscured and unobscured star-forming regions. Even though these star-forming complexes provide an additional heating source for the dust, the far-infrared/submillimetre emission long wards of 100 μm is underestimated by a factor of 3-4. This inconsistency in the dust energy budget of NGC 4565 suggests that a sizable fraction (two-thirds) of the total dust reservoir (Md ˜ 2.9 × 108 M⊙) consists of a clumpy distribution with no associated young stellar sources. The distribution of those dense dust clouds would be in such a way that they remain unresolved in current far-infrared/submillimetre observations and hardly contribute to the attenuation at optical wavelengths. More than two-thirds of the dust heating in NGC 4565 is powered by the old stellar population, with localized embedded sources supplying the remaining dust heating in NGC 4565. The results from this detailed dust energy balance study in NGC 4565 are consistent with that of similar analyses of other edge-on spirals.

  15. Regulation of energy balance by a gut-brain axis and involvement of the gut microbiota.

    PubMed

    Bauer, Paige V; Hamr, Sophie C; Duca, Frank A

    2016-02-01

    Despite significant progress in understanding the homeostatic regulation of energy balance, successful therapeutic options for curbing obesity remain elusive. One potential target for the treatment of obesity is via manipulation of the gut-brain axis, a complex bidirectional communication system that is crucial in maintaining energy homeostasis. Indeed, ingested nutrients induce secretion of gut peptides that act either via paracrine signaling through vagal and non-vagal neuronal relays, or in an endocrine fashion via entry into circulation, to ultimately signal to the central nervous system where appropriate responses are generated. We review here the current hypotheses of nutrient sensing mechanisms of enteroendocrine cells, including the release of gut peptides, mainly cholecystokinin, glucagon-like peptide-1, and peptide YY, and subsequent gut-to-brain signaling pathways promoting a reduction of food intake and an increase in energy expenditure. Furthermore, this review highlights recent research suggesting this energy regulating gut-brain axis can be influenced by gut microbiota, potentially contributing to the development of obesity.

  16. Preliminary energy balance and economic of a farm-scale ethanol plant

    SciTech Connect

    Jantzen, D.; McKinnon, T.

    1980-05-01

    A small-scale ethanol plant was designed, built, tested, and modified over the past 18 months. The plant currently operating is the second design. A third, and probably final, design will be installed and operating within a few months. The current plant produces approximately 30 gal/hr of 190-proof alcohol on a continuous basis. The new plant will produce 50 gal/hr of 200-proof alcohol. A key feature is the relatively low process heat requirement, which is achieved by extensive use of waste-heat recovery heat exchangers. This is manifested in the low temperatures of the process output streams. Acting on the request of the Office of Alcohol Fuels, US Department of Energy, and at the invitation of the owners, representatives from the Solar Energy Research Institute evaluated the energy balance on the plant. The objective was to help clear up the controversy surrounding the net energy benefit of ethanol production. Although the study was site-specific to the plant and limited in scope, it is indicative of the potential performance of grain-to-ethanol plants in general.

  17. A Novel Ultrasonic Method for Liquid Level Measurement Based on the Balance of Echo Energy.

    PubMed

    Zhang, Bin; Wei, Yue-Juan; Liu, Wen-Yi; Zhang, Yan-Jun; Yao, Zong; Zhang, Liang; Xiong, Ji-Jun

    2017-03-28

    This study presents a novel method for determining the liquid level from the outside of a sealed container, which is based on the balance of echo energy received by two receiving sensors. The proposed method uses one transmitting transducer and two receiving sensors that are encapsulated in a coupling plane and arranged by certain rules. The calculation and comparison of echo energy are grounded on the difference ultrasonic impedance between gas and liquid media. First, by analyzing the propagation and attenuation characteristics of ultrasonic waves in a solid, an acoustic model for calculating the echo energy is established and simulated in MATLAB. Second, the proposed method is evaluated through a series of experiments. The difference and ratio of echo energy received by two receiving sensors are calculated and compared under two different coupling conditions. Two kinds of the sensors that are arranged by different rules are selected for measuring the liquid level, and the measurement are analyzed and discussed in detail. Finally, the experimental results indicate that the proposed method can meet the proposed accuracy requirements and can effectively solve the problems caused by some poor coupling conditions.

  18. Deriving star formation histories from photometry using energy balance spectral energy distribution modelling

    NASA Astrophysics Data System (ADS)

    Smith, Daniel J. B.; Hayward, Christopher C.

    2015-10-01

    Panchromatic spectral energy distribution fitting is a critical tool for determining the physical properties of distant galaxies, such as their stellar mass and star formation rate. One widely used method is the publicly available MAGPHYS code. We build on our previous analysis by presenting some modifications which enable MAGPHYS to automatically estimate galaxy star formation histories (SFHs), including uncertainties, based on ultraviolet to far-infrared photometry. We use state-of-the art synthetic photometry derived by performing three-dimensional dust radiative transfer on hydrodynamic simulations of isolated disc and merging galaxies to test how well the modified MAGPHYS is able to recover SFHs under idealized conditions, where the true SFH is known. We find that while the SFH of the model with the best fit to the synthetic photometry is a poor representation of the true SFH (showing large variations with the line of sight to the galaxy and spurious bursts of star formation), median-likelihood SFHs generated by marginalizing over the default MAGPHYS libraries produce robust estimates of the smoothly varying isolated disc simulation SFHs. This preference for the median-likelihood SFH is quantitatively underlined by our estimates of χ ^2_SFH (analogous to the χ2 goodness-of-fit estimator) and Δ M / M (the integrated absolute mass discrepancy between the model and true SFH) that strongly prefer the median-likelihood SFHs over those that best fit the UV-to-far-IR photometry. In contrast, we are unable to derive a good estimate of the SFH for the merger simulations (either best fit or median likelihood) despite being able to obtain a reasonable fit to the simulated photometry, likely because the analytic SFHs with bursts superposed in the standard MAGPHYS library are insufficiently general/realistic.

  19. The urban energy balance of a lightweight low-rise neighborhood in Andacollo, Chile

    NASA Astrophysics Data System (ADS)

    Crawford, Ben; Krayenhoff, E. Scott; Cordy, Paul

    2016-10-01

    Worldwide, the majority of rapidly growing neighborhoods are found in the Global South. They often exhibit different building construction and development patterns than the Global North, and urban climate research in many such neighborhoods has to date been sparse. This study presents local-scale observations of net radiation (Q * ) and sensible heat flux (Q H ) from a lightweight low-rise neighborhood in the desert climate of Andacollo, Chile, and compares observations with results from a process-based urban energy-balance model (TUF3D) and a local-scale empirical model (LUMPS) for a 14-day period in autumn 2009. This is a unique neighborhood-climate combination in the urban energy-balance literature, and results show good agreement between observations and models for Q * and Q H . The unmeasured latent heat flux (Q E ) is modeled with an updated version of TUF3D and two versions of LUMPS (a forward and inverse application). Both LUMPS implementations predict slightly higher Q E than TUF3D, which may indicate a bias in LUMPS parameters towards mid-latitude, non-desert climates. Overall, the energy balance is dominated by sensible and storage heat fluxes with mean daytime Bowen ratios of 2.57 (observed Q H /LUMPS Q E )-3.46 (TUF3D). Storage heat flux (ΔQ S ) is modeled with TUF3D, the empirical objective hysteresis model (OHM), and the inverse LUMPS implementation. Agreement between models is generally good; the OHM-predicted diurnal cycle deviates somewhat relative to the other two models, likely because OHM coefficients are not specified for the roof and wall construction materials found in this neighborhood. New facet-scale and local-scale OHM coefficients are developed based on modeled ΔQ S and observed Q * . Coefficients in the empirical models OHM and LUMPS are derived from observations in primarily non-desert climates in European/North American neighborhoods and must be updated as measurements in lightweight low-rise (and other) neighborhoods in various

  20. Advances in the Two Source Energy Balance (TSEB) model using very high resolution remote sensing data in vineyards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The thermal-based Two Source Energy Balance (TSEB) model partitions the water and energy fluxes from vegetation and soil components providing thus the ability for estimating soil evaporation (E) and canopy transpiration (T) separately. However, it is crucial for ET partitioning to retrieve reliable ...

  1. Does Sport-Drink Use During Exercise Promote an Acute Positive Energy Balance?

    PubMed

    Dragusin, Iulian B; Horswill, Craig A

    2016-10-01

    Sports drinks have been implicated in contributing to obesity and chronic diseases by providing surplus calories and excess sugars. Using existing literature we compared energy intake from sports drinks consumed during exercise with the exercise-induced calorie expenditure to determine whether sports drink use might eliminate the energy deficit and jeopardize conditions for improved metabolic fitness. We identified 11 published studies that compared sport drink consumption to placebo during exercise with a primary focused on the effect of sport drinks or total carbohydrate content on enhancing physical performance. Energy expenditure (EE) was calculated using VO2, RER, and exercise duration for the exercise protocol. Energy ingestion (EI) was determined using the carbohydrate dosing regimen administered before and during the exercise protocol. A two-tailed t test was used to test whether the energy balance (EI-EE) was different from zero (alpha level = 0.05). Sport drink consumption during aerobic exercise of sufficient duration (≥ 60 min) did not abolish the energy deficit (p < .001). Mean ± SD were EE, 1600 ± 639 Cal; EI, 394 ± 289 Cal; and EI-EE,-1206+594 Cal; VO2, 3.05 ± 0.55 L/min; RER, 0.91 ± 0.04; exercise duration 110 ± 42 min. Ingesting sports drinks to enhance performance did not abolish the caloric deficit of aerobic exercise. Sports drinks can be used in accordance with research protocols that typically provide 30-60 g of carbohydrate per hour when exercising at adequate durations for moderate to high intensity and still maintain a substantive caloric deficit.

  2. The effect of cloud type on earth's energy balance - Results for selected regions

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    International Satellite Cloud Climatology Project (ISCCP) C1 cloud information is compared with planetary albedo, outgoing longwave radiation (OLR), and net radiation measured at the top of the atmosphere by the Earth Radiation Budget Experiment (ERBE). Principal component analysis indicates that the day-to-day variations of the abundances of the 35 cloud types of the C1 data are correlated with each other, so that for many purposes the data set can be well represented by about five cloud types. Using stepwise multiple regression, the ISCCP C1 data can be used to predict the day-to-day variations of the energy balance measured by ERBE for 2.5-deg regions. Total fractional area coverage of cloudiness is a relatively poor predictor of radiation budget quantities. If the total fractional area coverage by clouds is divided into contributions from several distinct cloud types, the fractional coverages by these several cloud types will together form a much better prediction of radiation budget quantities than the single variable of total fractional-area cloud coverage. The regression equations can be used to estimate the net effect of clouds on the radiation balance and the contributions from particular types of clouds to albedo, OLR, and net radiation.

  3. The relationship between dietary intake, exercise, energy balance and the space craft environment

    NASA Technical Reports Server (NTRS)

    Stein, T. P.

    2000-01-01

    Space flight is associated with the loss of skeletal muscle, principally from muscles with anti-gravity functions. Examination of data across different missions can permit a distinction to be made between true microgravity responses and what are mission-specific responses. Protein metabolism has been investigated on six missions, four short-term [Shuttle missions Space Life Sciences 1 (1991, SLSI), Space Life Sciences 2 (1993, SLS2), Deutsche-2 (1993, D2) and the Life and Microgravity Sciences (1996, LMS)] and two long-term missions (Skylab 1993 and NASA/MIR, 1996-1998). Measurements made include dietary intake (six missions), nitrogen balance (four missions), whole-body protein kinetics with [15N]glycine as the tracer (four missions) and cortisol excretion (three missions). Also available for comparison are bed rest studies with and without exercise. The purpose of this paper is to see what can be learnt about the muscle loss problem by comparing metabolic results across the six missions for which data are available and against bed rest. The analysis suggests that there is a linkage between the inability to maintain energy balance and exercise, and the connection is the decreased efficiency of removal of the metabolic by-products of exercise (heat, CO2) during space flight.

  4. Long-term energy flux measurements and energy balance over a small boreal lake using eddy covariance technique

    NASA Astrophysics Data System (ADS)

    Nordbo, Annika; Launiainen, Samuli; Mammarella, Ivan; LeppäRanta, Matti; Huotari, Jussi; Ojala, Anne; Vesala, Timo

    2011-01-01

    Measurements of the energy balance components of a small boreal lake (area 0.041 km2, mean depth 2.5 m) in southern Finland were performed during four open water periods (April-October) in 2005-2008. Turbulent fluxes of sensible and latent heat acquired using the eddy covariance technique were accompanied by net radiation and water heat storage measurements. In April the lake was near isothermal, whereas in May the development of a thermocline was enabled by dark water color and a sheltered location. The thermocline continued to deepen until September down to the depth of 3.5 m and prevented the deeper water from interacting with the atmosphere. The sensible heat flux was governed by the air-water temperature difference and had its minimum in the afternoon (values down to -45 W m-2) and peaked in the early morning (values up to 32 W m-2). The monthly means ranged from -9 W m-2 (April 2005) to 24 W m-2 (July 2008). The diurnal variation of the latent heat flux, controlled by vapor pressure deficit, had an opposite diurnal phase with a maximum in the afternoon (values up to 120 W m-2) and minimum in the morning (values down to ˜2 W m-2). The monthly averages ranged from 4 W m-2 (October 2008) to 77 W m-2 (July 2006). Furthermore, the lake acted as a heat sink until July and August when the maximum heat content was about 230 MJ m-2. The monthly energy balance closure varied from 57% to 112%, and the average closure was 82% (residual 16 W m-2) and 72% (residual 23 W m-2) for 2006 and 2007, respectively.

  5. Towards a more detailed representation of the energy balance in a coupled land surface model

    NASA Astrophysics Data System (ADS)

    Ryder, J.; Polcher, J.; Luyssaert, S.

    2012-04-01

    Currently, the land-surface region sequesters 25% of global CO2 emissions. In addition to climate change, increasing atmospheric CO2 concentrations, fertilisation and nitrogen deposition, this sink is thought to be largely due to land management. When applied deliberately to enhance the terrestrial carbon sink strength, this land management may have unintended effects on the energy budget, potentially offsetting the radiative effect of carbon sequestration. As with other land surface models, the present release of ORCHIDEE (the land surface model of the IPSL Earth system model) has difficulties in reproducing consistently observed energy balances (Pitman et al., 2009; Jimenez et al., 2011; de Noblet-Ducoudré et al., 2011). Hence, the model must be improved to be better able to study the radiative effect of forest management and land use change. This observation serves as a starting point in this research - improving the level of detail in energy balance simulations of the surface layer. We here outline the structure of a new detailed and practical simulation of the energy budget that is currently under development within the surface model ORCHIDEE, and will be coupled to the atmospheric model LMDZ. The most detailed simulations of the surface layer energy budget are detailed iterative multi-layer canopy models, such as Ogeé et al. (2003), which are linked to specific measurement sites and do not interact with the atmosphere. In this current project, we aim to create a model that will implement the insights obtained in those previous studies and improve upon the present ORCHIDEE parameterisation, but will run stably and efficiently when coupled to an atmospheric model. This work involves a replacement of the existing allocation of 14 different types of vegetation within each surface tile (the 'Plant Functional Types') by a more granular scheme that can be modified to reflect changes in attributes such as vegetation density, leaf type, distribution (clumping

  6. Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2016-08-16

    Balance functions have been measured in terms of relative pseudorapidity ( Δη ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider (RHIC) from Au + Au collisions atmore » $$\\sqrt{s}$$$_{NN}$$ = 7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at $$\\sqrt{s}$$$_{NN}$$ = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). Finally, the narrowing of the balance function in central collisions at $$\\sqrt{s}$$$_{NN}$$ = 7.7 GeV implies that a QGP is still being created at this relatively low energy.« less

  7. Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng,; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Han, L. -X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2016-08-16

    Balance functions have been measured in terms of relative pseudorapidity ( Δη ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider (RHIC) from Au + Au collisions at $\\sqrt{s}$$_{NN}$ = 7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at $\\sqrt{s}$$_{NN}$ = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). Finally, the narrowing of the balance function in central collisions at $\\sqrt{s}$$_{NN}$ = 7.7 GeV implies that a QGP is still being created at this relatively low energy.

  8. Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-08-01

    Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.

  9. Energy Balance and Hydrological Modelling of Zongo Glacier, Bolivia, Using ERA-40 Reanalysis Data

    NASA Astrophysics Data System (ADS)

    Duguay, M.; Hock, R.; Sicart, J.; Coudrain, A.

    2008-12-01

    In the Andes several regions profit significantly from glacial melt water for drink water supply and electricity production. During the dry season, glacier melt is significant source of water in the semi-arid region of La Paz, Bolivia. The Andean glaciers are retreating and water resources after reaching a culmination, will decrease. This implicates serious environmental and socio-economical consequences. For an effective attenuation, it is crucial to furnish quantitative predictions of the glacier mass loss and its effects on the water resources in these regions. A distributed energy balance model has been developed to model mass balance and melt induced discharge of tropical glaciers. We want to predict the changes in glacier melt discharge in response to future climate change for the region of La Paz, Bolivia and later regionalize the model to a larger area. The model operates on daily steps, has a 20 m grid resolution, and is forced by daily data of air temperature, humidity, wind speed, global radiation and precipitation. As a test basin, we calibrate the model at Glaciar Zongo, Bolivia, 16°15'S , 68°°10'W which is monitored by the French Institute for Research for the Development (IRD) . Zongo Glacier is a 1,8 km2 large and the catchment is 63% glacierized. Mass balance, weather station and discharge data are available on daily basis from 1991 onward. The measurements have gaps and only two years (1994-95 and 1999-00) with continuous data are available. In order to allow for multi-year simulations we force the model by daily ERA-40 reanalysis data from the European Center for Weather Forecast (ECMWF). To downscale the data we compare the daily data 1991-2002 to the observations at the glacier. Results indicate a fair agreement for air temperature, but a rather poor correlation between the ERA-40 data and the observations for wind speed, global radiation and precipitation. The correlation is improved using monthly values. So far, test runs of the model

  10. Mapping surface energy balance components by combining landsat thematic mapper and ground-based meteorological data

    USGS Publications Warehouse

    Moran, M.S.; Jackson, R. D.; Raymond, L.H.; Gay, L.W.; Slater, P.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 (??E) and net radiant flux density (Rn) were produced using Landsat Thematic Mapper (TM) data for three dates: 23 July 1985, 5 April 1986, and 24 June 1986. On each date, a Bowen-ratio apparatus, located in a vegetated field, was used to measure ??E and Rn at a point within the field. Estimates of ??E and Rn were also obtained using radiometers aboard an aircraft flown at 150 m above ground level. The TM-based estimates differed from the Bowen-ratio and aircraft-based estimates by less than 12 % over mature fields of cotton, wheat, and alfalfa, where ??E and Rn ranged from 400 to 700 Wm-2. ?? 1989.

  11. Interannual variability of the global net radiation balance and its consequence on global energy transport

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Sohn, B. J.

    1990-01-01

    Global cloudiness and radiation budget data from Nimbus 6 and 7 are used to investigate the role of cloud and surface radiative forcing and elements of the earth's general circulation. Although globally integrated cloud forcing is nearly zero, there are large regional imbalances and well regulated processes in the shortwave and longwave spectrum that control the meridional gradient structure of the net radiation balance and the factors modulating the east-west oriented North Africa-western Pacific energy transport dipole. The analysis demonstrates that clouds play a dual role in both the shortwave and longwave spectra in terms of tropical and midlatitude east-west gradients. The key result is that cloud forcing, although not always the principle regulator of interannual variability of the global climate, serves to reinforce the basic three-cell meridional circulation.

  12. Sensitivity of an energy balance climate model with predicted snowfall rates

    NASA Technical Reports Server (NTRS)

    Bowman, K. P.

    1985-01-01

    A snowfall parameterization and a polar-ice-sheet model are developed and applied to the two-level zonally averaged seasonal energy-balance climate model of Held and Suarez (1979), and sensitivity experiments involving changes in insolation are performed both with and without ice sheets. The results are presented in tables and graphs, and the hydrological-cycle response to insolation changes is found to be similar to that predicted by global-circulation models employing prescribed precipitation levels, with a somewhat higher sensitivity in the snow line. The area covered by ice sheets in the ice-sheet models is shown to be greater than that covered by permanent snow in the models without ice sheets, an effect attributed to lower surface temperatures over the ice. It is inferred that an increase in the solar constant can cause increased high-latitude precipitation but not an ice age.

  13. Role of the Glucagon-Like-Peptide-1 Receptor in the Control of Energy Balance

    PubMed Central

    Hayes, Matthew R.; De Jonghe, Bart C.; Kanoski, Scott E.

    2010-01-01

    The peripheral and central glucagon-like-peptide-1 (GLP-1) systems play an essential role in glycemic and energy balance regulation. Thus, pharmacological targeting of peripheral and/or central GLP-1 receptors (GLP-1R) may represent a potential long-term treatment option for both obesity and type-II diabetes mellitus (T2DM). Uncovering and understanding the neural pathways, physiological mechanisms, specific GLP-1R populations, and intracellular signaling cascades that mediate the food intake inhibitory and incretin effects produced by GLP-1R activation are vital to the development of these potential successful therapeutics. Particular focus will be given to the essential role of the nucleus tractus solitarius (NTS) in the caudal brainstem, as well as the gut-to-brain communication by vagal afferent fibers in mediating the physiological and behavioral responses following GLP-1R activation. PMID:20226203

  14. Role of the endocannabinoid system in energy balance regulation and obesity.

    PubMed

    Cota, Daniela

    2008-01-01

    The endogenous cannabinoid system (ECS) is a neuromodulatory system recently recognized to have a role in the regulation of various aspects of eating behavior and energy balance through central and peripheral mechanisms. In the central nervous system, cannabinoid type 1 receptors and their endogenous ligands, the endocannabinoids, are involved in modulating food intake and motivation to consume palatable food. Moreover, the ECS is present in peripheral organs, such as liver, white adipose tissue, muscle, and pancreas, where it seems to be involved in the regulation of lipid and glucose homeostasis. Dysregulation of the ECS has been associated with the development of obesity and its sequelae, such as dyslipidemia and diabetes. Conversely, recent clinical trials have shown that cannabinoid type 1 receptor blockade may ameliorate these metabolic abnormalities. Although further investigation is needed to better define the actual mechanisms of action, pharmacologic approaches targeting the ECS may provide a novel, effective option for the management of obesity, type 2 diabetes and cardiovascular disease.

  15. Genome-scale estimate of the metabolic turnover of E. Coli from the energy balance analysis

    NASA Astrophysics Data System (ADS)

    De Martino, D.

    2016-02-01

    In this article the notion of metabolic turnover is revisited in the light of recent results of out-of-equilibrium thermodynamics. By means of Monte Carlo methods we perform an exact sampling of the enzymatic fluxes in a genome scale metabolic network of E. Coli in stationary growth conditions from which we infer the metabolites turnover times. However the latter are inferred from net fluxes, and we argue that this approximation is not valid for enzymes working nearby thermodynamic equilibrium. We recalculate turnover times from total fluxes by performing an energy balance analysis of the network and recurring to the fluctuation theorem. We find in many cases values one of order of magnitude lower, implying a faster picture of intermediate metabolism.

  16. Quantitative prediction and interpretation of spin energy gaps in polyradicals: the virtual magnetic balance.

    PubMed

    Barone, Vincenzo; Cacelli, Ivo; Ferretti, Alessandro; Prampolini, Giacomo

    2017-03-29

    Open-shell organic molecules possessing more than two unpaired electrons and sufficient stability even at room temperature are very unusual, but few were recently synthesized that promise a number of fascinating applications. Unfortunately, reliable structural information is not available and only lower limits can be estimated for energy splittings between the different spin states. On these grounds, we introduce here an effective 'virtual magnetic balance', a robust and user-friendly tool purposely tailored for polyradicals and devised to be used in parallel with experimental studies. The main objective of this tool is to provide reliable structures and quantitative splittings of spin states of large, complex molecules. We achieved this objective with reasonable computation times and in a theoretical framework that allows disentanglement of different stereo-electronic effects contributing to the overall experimental result. A recently synthesized tetraradical with remarkable chemical stability was used as a case study.

  17. Enthalpy By Energy Balance for Aerodynamic Heating Facility at NASA Ames Research Center Arc Jet Complex

    NASA Technical Reports Server (NTRS)

    Hightower, T. Mark; MacDonald, Christine L.; Martinez, Edward R.; Balboni, John A.; Anderson, Karl F.; Arnold, Jim O. (Technical Monitor)

    2002-01-01

    The NASA Ames Research Center (ARC) Arc Jet Facilities' Aerodynamic Heating Facility (AHF) has been instrumented for the Enthalpy By Energy Balance (EB2) method. Diagnostic EB2 data is routinely taken for all AHF runs. This paper provides an overview of the EB2 method implemented in the AHF. The chief advantage of the AHF implementation over earlier versions is the non-intrusiveness of the instruments used. For example, to measure the change in cooling water temperature, thin film 1000 ohm Resistance Temperature Detectors (RTDs) are used with an Anderson Current Loop (ACL) as the signal conditioner. The ACL with 1000 ohm RTDs allows for very sensitive measurement of the increase in temperature (Delta T) of the cooling water to the arc heater, which is a critical element of the EB2 method. Cooling water flow rates are measured with non-intrusive ultrasonic flow meters.

  18. Balanced Basis Sets in the Calculation of Potential Energy Curves for Diatomic Molecules.

    NASA Astrophysics Data System (ADS)

    Barclay, V. J.

    "Balanced" basis sets, which describe the internuclear region as well as the nuclear region, are examined in the context of an ab initio selection-extrapolation configuration -interaction method (MRD-CI). The sets are balanced by adding bond functions (BF's), which are s, p and d-type orbitals at the bond mid-point, to atomic-centred molecular basis sets, which have double and triple sets of valence -shell orbitals (DZ and TZ) and one or two sets of polarization functions (PF's). Potential energy curves and spectroscopic constants were calculated for the ground states of the hydrides H _2, OH, NaH, MgH, MH, SiH, PH, SH, HCl, and for the ionized species OH^+ and OH^{++}, and for the A^3Sigma_{u}, w^3Delta_{u} and B^3Pi_{g} excited states of N_2. The basis sets containing bond functions gave curves and constants superior to the DZP and (where calculated) TZPP results, and of quality similar to large basis set calculations in the literature. The single and double ionization potentials of OH, and the term energies of the N_2 excited states had error at the atomic asymptotes for all basis sets. The dissociation energies of the ground states of ten first-row diatomics (C_2, N_2, O_2, F_2, CN, CO, CF, NO, NF, and FO) were studied using balanced basis sets. A correlation was found to exist between the actual bond order of a species, and the number and kinds of orbitals which comprise the optimum BF. For MRD-CI diatomic calculations, the following BF's should be added to a DZP basis set (sp) (for a bond order of 1); 2(sp) (B. O. 1.5); (spd) (B. O. 2); 3(sp) (B. O. 2.5); 2(spd) (B. O. 3). The prescribed BF basis method was tested on the 26 second-row congeners Si _2, P_2, S _2, Cl_2, SiP, SiS, SiCl, PS, PCl, and ClS, and mixed-row congeners SiN, SiO, SiF, PO, PF, SF, SiC, PN, SO, ClF, CP, CS, CCl, NS, NCl, and ClO. An average error of 6% and a maximum error of 10% relative to known experimental D_{e }'s was found: compared to an average error of 18% for TZPP calculations

  19. Climate studies with a multilayer energy balance model. III - Climatic impact of stratospheric volcanic aerosols

    NASA Technical Reports Server (NTRS)

    Chou, M.-D.; Arking, A.; Peng, L.

    1984-01-01

    A multilayer energy balance model is applied in an examination of the sensitivity of climate to stratospheric aerosols induced by volcanic eruptions. Zonally and annually averaged quantities are considered, with ocean and land temperatures computed separately and the atmosphere below the 200 mb level divided into eight layers of 24 sublayers each. The aerosol is assumed to form in the 150-200 mb range. Aerosol parameters for radiative transfer calculations are reflection in the solar spectral region and absorption in the solar and IR regions. A 75 percent aqueous solution of sulfuric acid is assumed for the aerosols. The sensitivity of the hemispherically averaged surface temperature is enhanced 37 percent, with a 20 percent uncertainty, when the thermal IR radiation is excluded. The solar radiation enhances the surface temperatures to a higher degree than the thermal radiation. The maximum response to the evenly distributed aerosols is in the 60-70 deg N latitudes and propagates, weakening, to lower latitudes.

  20. Energy and mass balance in the three-phase interstellar medium

    NASA Technical Reports Server (NTRS)

    Wang, Zhong; Cowie, Lennox L.

    1988-01-01

    Details of the energy and mass balances are considered in the context of a three-phase interstellar medium. The rates of mass exchange between the different phases are derived based on the pressure variations created by supernova remnant expansions. It is shown that the pressure-confined warm and cold gases have stable temperatures under a variety of interstellar conditions. The three-phase quasi-static configuration is found to be a natural outcome, and both warm and cold phases generally contribute about half of the total mass density to the diffuse interstellar gas. The model is also likely to be self-regulatory in the sense that variations of the input parameters do not strongly alter the general result, which is consistent with most current observations. The consequences of extreme conditions on this model are considered, and the possible implications for interstellar medium in other galaxies are briefly discussed.

  1. Use of ground-based remotely sensed data for surface energy balance calculations during Monsoon '90

    NASA Technical Reports Server (NTRS)

    Moran, M. S.; Kustas, William P.; Vidal, Alain; Stannard, David I.; Blanford, James

    1991-01-01

    Surface energy balance was evaluated at a semiarid watershed using direct and indirect measurements of the turbulent fluxes, a remote technique based on measurements of surface reflectance and temperature, and conventional meteorological information. Comparison of remote estimates of net radiant flux and soil heat flux densities with measured values showed errors on the order of +/-40 W/sq m. To account for the effects of sparse vegetation, semi-empirical adjustments to aerodynamic resistance were required for evaluation of sensible heat flux density (H). However, a significant scatter in estimated versus measured latent heat flux density (LE) was still observed, +/-75 W/sq m over a range from 100-400 W/sq m. The errors of H and LE estimates were reduced to +/-50 W/sq m when observations were restricted to clear sky conditions.

  2. Climate change from the perspective of the surface energy balance and global hydrologic cycle

    NASA Astrophysics Data System (ADS)

    Ramaswamy, V.; Ming, Y.; Schwarzkopf, M. D.

    2015-12-01

    Major changes have occurred in the radiative drive of the surface since preindustrial times owing to both changes in the emissions of greenhouse gases and aerosols. These are to be contrasted with the drive at the top-of-the-atmosphere. Using global climate models and multiple observations of the surface fluxes from various platforms, we discuss how the energy balance has evolved with time and the manner in which this has affected the hydrologic cycle, including an account of the critical uncertainties. We make use of the simulations performed with global climate models and used in the IPCC assessments to diagnose the factors that are principally responsible for the changes, the contrasting atmospheric mechanisms exerted by greenhouse gases and aerosols, and the relative roles of the atmospheric constituents.

  3. Controlling the subtle energy balance in protic ionic liquids: dispersion forces compete with hydrogen bonds.

    PubMed

    Fumino, Koichi; Fossog, Verlaine; Stange, Peter; Paschek, Dietmar; Hempelmann, Rolf; Ludwig, Ralf

    2015-02-23

    The properties of ionic liquids are determined by the energy-balance between Coulomb-interaction, hydrogen-bonding, and dispersion forces. Out of a set of protic ionic liquids (PILs), including trialkylammonium cations and methylsulfonate and triflate anions we could detect the transfer from hydrogen-bonding to dispersion-dominated interaction between cation and anion in the PIL [(C6 H13 )3 NH][CF3 SO3 ]. The characteristic vibrational features for both ion-pair species can be detected and assigned in the far-infrared spectra. Our approach gives direct access to the relative strength of hydrogen-bonding and dispersion forces in a Coulomb-dominated system. Dispersion-corrected density functional theory (DFT) calculations support the experimental findings. The dispersion forces could be quantified to contribute about 2.3 kJ mol(-1) per additional methylene group in the alkyl chains of the ammonium cation.

  4. Steady-state solutions of a diffusive energy-balance climate model and their stability

    NASA Technical Reports Server (NTRS)

    Ghil, M.

    1975-01-01

    A diffusive energy-balance climate model, governed by a nonlinear parabolic partial differential equation, was studied. Three positive steady-state solutions of this equation are found; they correspond to three possible climates of our planet: an interglacial (nearly identical to the present climate), a glacial, and a completely ice-covered earth. Models similar to the main one are considered, and the number of their steady states was determined. All the models have albedo continuously varying with latitude and temperature, and entirely diffusive horizontal heat transfer. The stability under small perturbations of the main model's climates was investigated. A stability criterion is derived, and its application shows that the present climate and the deep freeze are stable, whereas the model's glacial is unstable. The dependence was examined of the number of steady states and of their stability on the average solar radiation.

  5. Multiobjective calibration and sensitivity of a distributed land surface water and energy balance model

    NASA Astrophysics Data System (ADS)

    Houser, Paul R.; Gupta, Hoshin V.; Shuttleworth, W. James; Famiglietti, James S.

    2001-12-01

    The feasibility of using spatially distributed information to improve the predictive ability of a spatially distributed land surface water and energy balance model (LSM) was explored at the U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) Walnut Gulch Experimental Watershed in southeastern Arizona. The inclusion of spatially variable soil and vegetation information produced unrealistic simulations that were inconsistent with observations, which was likely an artifact of both discretely assigning a single set of parameters to a given area and inadequate knowledge of spatially varying parameter values. Because some of the model parameters were not measured or are abstract quantities a multiobjective least squares strategy was used to find catchment averaged parameter values that minimize the prediction error of latent heat flux, soil heat flux, and surface soil moisture. This resulted in a substantial improvement in the model's spatially distributed performance and yielded valuable insights into the interaction and optimal selection of model parameters.

  6. 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 ...

  7. On the energy balance closure and net radiation in complex terrain

    PubMed Central

    Wohlfahrt, Georg; Hammerle, Albin; Niedrist, Georg; Scholz, Katharina; Tomelleri, Enrico; Zhao, Peng

    2017-01-01

    In complex, sloping terrain, horizontal measurements of net radiation are not reflective of the radiative energy available for the conductive and convective heat exchange of the underlying surface. Using data from a grassland site on a mountain slope characterised by spatial heterogeneity in inclination and aspect, we tested the hypothesis that a correction of the horizontal net radiation measurements which accounts for the individual footprint contributions of the various surfaces to the measured sensible and latent heat eddy covariance fluxes will yield more realistic slope-parallel net radiation estimates compared to a correction based on the average inclination and aspect of the footprint. Our main result is that both approaches led to clear, but very similar improvements in the phase between available energy and the sum of the latent and sensible heat fluxes. As a consequence the variance in the sum of latent and sensible heat flux explained by available radiation improved by >10 %, while energy balance closure improved only slightly. This is shown to be mainly due to the average inclination and aspect corresponding largely with the inclination and aspect of the main flux source area in combination with a limited sensitivity of the slope correction to small angular differences in, particularly, inclination and aspect. We conclude with a discussion of limitations of the present approach and future research directions. PMID:28066093

  8. Starch levels on performance, milk composition and energy balance of lactating dairy cows.

    PubMed

    Carmo, Carolina Almeida; Batistel, Fernanda; de Souza, Jonas; Martinez, Junio Cesar; Correa, Paulo; Pedroso, Alexandre Mendonça; Santos, Flávio Augusto Portela

    2015-01-01

    The objective of this experiment was to evaluate the effects of starch levels in diets with the replacement of citrus pulp for corn on milk yield, milk composition, and energy balance of lactating dairy cows. Twenty-eight multiparous Holstein cows were used in seven 4 × 4 Latin squares conducted concurrently, and each experimental period consisted of 20 days (16 days for adaptation and 4 days for sampling). The experimental treatments comprised four starch levels: 15, 20, 25, and 30% in the diet. The dry matter intake increased linearly with increasing starch levels. The milk yield and 3.5% fat-corrected milk yield showed quadratic response to increasing starch levels. The milk protein content and milk total solids content responded linearly to increasing starch levels. The feed efficiency, milk lactose content, milk urea nitrogen, plasma urea nitrogen, and plasma glucose concentration were not affected by starch levels. The estimated net energy for lactation (NEL) intake increased linearly as the starch level was raised. Although the milk NEL output per kilogram of milk was not affected by starch, the milk NEL output daily responded quadratically to starch levels. In addition, the NEL in body weight gain also responded quadratically to increasing starch levels. The efficiency of energy use for milk yield and the NEL efficiency for production also responded quadratically to increasing starch levels. Diets for mid-lactating dairy cows producing around 30 kg/day of milk should be formulated to provide around 25% starch to optimize performance.

  9. Quantification of pathways of glucose utilization and balance of energy metabolism of rabbit reticulocytes.

    PubMed

    Siems, W; Müller, M; Dumdey, R; Holzhütter, H G; Rathmann, J; Rapoport, S M

    1982-06-01

    In this work it is demonstrated that glucose constitutes the main substrate of energy metabolism of rabbit reticulocytes under aerobic conditions in the presence of 5 mM glucose. Amino acids and fatty acids are minor sources of energy. The shares of processes utilizing glucose in reticulocytes were estimated from tracer experiments. A new mathematical technique used permits the derivation of closed terms for the specific radioactivity of single positions of C atoms of the metabolites of the citrate cycle. By means of regression analysis, the undetermined flux rates in the citrate cycle were calculated. On the basis of the data an overall balance sheet of glucose utilization and of ATP generation is given. About 45% of the glucose of reticulocytes is catabolized via the citrate cycle, about the same percentage yields lactate. Only 2% of the glucose was oxidized in the oxidative pentose pathway whereas the remainder is used for the formation of serine and glycine required for hemoglobin synthesis. These results are related to knowledge about the main processes utilizing ATP in reticulocytes, i.e. the synthesis of hemoglobin and the energy-dependent proteolysis. Our approach to the investigation of metabolic relations in the reticulocytes can be applied to other tissues in which equilibria between large metabolite pools play a role.

  10. Balancing Power Absorption and Fatigue Loads in Irregular Waves for an Oscillating Surge Wave Energy Converter

    SciTech Connect

    Tom, Nathan M.; Yu, Yi-Hsiang; Wright, Alan D.; Lawson, Michael

    2016-06-24

    The aim of this paper is to describe how to control the power-to-load ratio of a novel wave energy converter (WEC) in irregular waves. The novel WEC that is being developed at the National Renewable Energy Laboratory combines an oscillating surge wave energy converter (OSWEC) with control surfaces as part of the structure; however, this work only considers one fixed geometric configuration. This work extends the optimal control problem so as to not solely maximize the time-averaged power, but to also consider the power-take-off (PTO) torque and foundation forces that arise because of WEC motion. The objective function of the controller will include competing terms that force the controller to balance power capture with structural loading. Separate penalty weights were placed on the surge-foundation force and PTO torque magnitude, which allows the controller to be tuned to emphasize either power absorption or load shedding. Results of this study found that, with proper selection of penalty weights, gains in time-averaged power would exceed the gains in structural loading while minimizing the reactive power requirement.

  11. Monitoring crop coefficient of orange orchards using energy balance and the remote sensed NDVI

    NASA Astrophysics Data System (ADS)

    Consoli, Simona; Cirelli, Giuseppe Luigi; Toscano, Attilio

    2006-09-01

    The structure of vegetation is paramount in regulating the exchange of mass and energy across the biosphereatmosphere interface. In particular, changes in vegetation density affected the partitioning of incoming solar energy into sensible and latent heat fluxes that may result in persistent drought through reductions in agricultural productivity and in the water resources availability. Limited research with citrus orchards has shown improvements to irrigation scheduling due to better water-use estimation and more appropriate timing of irrigation when crop coefficient (Kc) estimate, derived from remotely sensed multispectral vegetation indices (VIs), are incorporated into irrigation-scheduling algorithms. The purpose of this article is the application of an empirical reflectance-based model for the estimation of Kc and evapotranspiration fluxes (ET) using ground observations on climatic data and high-resolution VIs from ASTER TERRA satellite imagery. The remote sensed Kc data were used in developing the relationship with the normalized difference vegetation index (NDVI) for orange orchards during summer periods. Validation of remote sensed data on ET, Kc and vegetation features was deal through ground data observations and the resolution of the energy balance to derive latent heat flux density (λE), using measures of net radiation (Rn) and soil heat flux density (G) and estimate of sensible heat flux density (H) from high frequency temperature measurements (Surface Renewal technique). The chosen case study is that of an irrigation area covered by orange orchards located in Eastern Sicily, Italy) during the irrigation seasons 2005 and 2006.

  12. Power-balancing instantaneous optimization energy management for a novel series-parallel hybrid electric bus

    NASA Astrophysics Data System (ADS)

    Sun, Dongye; Lin, Xinyou; Qin, Datong; Deng, Tao

    2012-11-01

    Energy management(EM) is a core technique of hybrid electric bus(HEB) in order to advance fuel economy performance optimization and is unique for the corresponding configuration. There are existing algorithms of control strategy seldom take battery power management into account with international combustion engine power management. In this paper, a type of power-balancing instantaneous optimization(PBIO) energy management control strategy is proposed for a novel series-parallel hybrid electric bus. According to the characteristic of the novel series-parallel architecture, the switching boundary condition between series and parallel mode as well as the control rules of the power-balancing strategy are developed. The equivalent fuel model of battery is implemented and combined with the fuel of engine to constitute the objective function which is to minimize the fuel consumption at each sampled time and to coordinate the power distribution in real-time between the engine and battery. To validate the proposed strategy effective and reasonable, a forward model is built based on Matlab/Simulink for the simulation and the dSPACE autobox is applied to act as a controller for hardware in-the-loop integrated with bench test. Both the results of simulation and hardware-in-the-loop demonstrate that the proposed strategy not only enable to sustain the battery SOC within its operational range and keep the engine operation point locating the peak efficiency region, but also the fuel economy of series-parallel hybrid electric bus(SPHEB) dramatically advanced up to 30.73% via comparing with the prototype bus and a similar improvement for PBIO strategy relative to rule-based strategy, the reduction of fuel consumption is up to 12.38%. The proposed research ensures the algorithm of PBIO is real-time applicability, improves the efficiency of SPHEB system, as well as suite to complicated configuration perfectly.

  13. Wind speed effects on leaf energy balance, transpiration and water use efficiency

    NASA Astrophysics Data System (ADS)

    Schymanski, S. J.; Or, D.

    2014-12-01

    Transpiration and heat exchange rates by plant leaves involve coupled physiological processes of significant ecohydrological importance. Prediction of the effects of changing environmental conditions such as irradiance, temperature, humidity and wind speed requires a thorough understanding of these processes. The common assumption that leaf temperature equals air temperature may introduce significant bias into estimates of transpiration rates and water use efficiency (WUE, the amount of carbon gained by photosynthesis per unit of water lost by transpiration). Theoretical considerations and observations suggest that leaf temperatures may deviate substantially from air temperature under typical environmental conditions, leading to greatly modified transpiration rates compared to isothermal conditions. In particular, effects of wind on gas exchange must consider feedbacks with leaf temperature. Systematic quantification of the effects of wind speed on leaf heat and gas exchange rates yield some surprising insights. We found a range of conditions where increased wind speed can suppress transpiration rates. The result reflects unintuitive feedbacks between sensible heat flux, leaf temperature, leaf-to-air vapour pressure deficit and latent heat flux. Modelling results suggest that with high wind speeds the same leaf conductance (for water vapour and carbon dioxide) can be maintained with less evaporative losses. This leads to positive relation between water use efficiency and wind speed across a wide range of conditions. The presentation will report results from a lab experiment allowing separation of the different leaf energy balance components under fully controlled conditions (wind speed, temperature, humidity, irradiance) and put them into perspective with a detailed leaf energy balance model and the commonly used Penman-Monteith equation.

  14. Importance of Soil Moisture and Vegetation Cover for Energy Balance partition in Burkina Faso

    NASA Astrophysics Data System (ADS)

    Ceperley, N. C.; Mande, T.; Tyler, S. W.; Bou-Zeid, E.; Van De Giesen, N.; Parlange, M. B.

    2015-12-01

    Land surface characteristics are the main control on hydrologic processes, the driver of most livelihoods, in semi arid West Africa. We use the energy and water balance measured with two eddy-covariance towers, coupled with a dense network of small, wireless meteorological stations in a small (3.5 km2) catchment to understand these relationships. Time series of monthly averages of soil moisture, rainfall, air temperature, cloud cover, components of net radiation, wind speed, and NDVI are presented in relation to the evaporative fraction and energy balance. We found that both latent and sensible heat fluxes are greater over mixed forest and savanna areas compared agricultural land. Sensible heat is found to be most different between the two land-covers at the end of the year, when the grass and vegetation is dry, and latent heat is found to be most different at the beginning of the year, when bare ground dominates. Further examination shows that soil moisture and vegetation indexes provide the main controls on evaporative fraction. These findings have implications for modeling the evaporation over large regions based on remotely sensed land surface temperature. The site is characteristic of the contrasts in vegetation and moisture availability present in the rocky escarpments found in Northern Benin and Southeastern Burkina Faso. Historically these sites are important in location for village choice and land use designation. These findings reinforce local cultural beliefs of the importance of vegetation for climate regulation and may provide support to local farmers for improving the resilience of natural resources and livelihood security.

  15. Energy balance and fitness in adult survivors of childhood acute lymphoblastic leukemia

    PubMed Central

    DeLany, James P.; Kaste, Sue C.; Mulrooney, Daniel A.; Pui, Ching-Hon; Chemaitilly, Wassim; Karlage, Robyn E.; Lanctot, Jennifer Q.; Howell, Carrie R.; Lu, Lu; Srivastava, Deo Kumar; Robison, Leslie L.; Hudson, Melissa M.

    2015-01-01

    There is limited information on body composition, energy balance, and fitness among survivors of childhood acute lymphoblastic leukemia (ALL), especially those treated without cranial radiation therapy (CRT). This analysis compares these metrics among 365 ALL survivors with a mean age of 28.6 ± 5.9 years (149 treated with and 216 without CRT) and 365 age-, sex-, and race-matched peers. We also report risk factors for outcomes among survivors treated without CRT. Male survivors not exposed to CRT had abnormal body composition when compared with peers (% body fat, 26.2 ± 8.2 vs 22.7 ± 7.1). Survivors without CRT had similar energy balance but had significantly impaired quadriceps strength (−21.9 ± 6.0 Newton-meters [Nm]/kg, 60°/s) and endurance (−11.4 ± 4.6 Nm/kg, 300°/s), exercise capacity (−2.0 ± 2.1 ml/kg per minute), low-back and hamstring flexibility (−4.7 ± 1.6 cm), and dorsiflexion range of motion (−3.1 ± 0.9°) and higher modified total neuropathy scores (+1.6 ± 1.1) than peers. Cumulative asparaginase dose ≥120 000 IU/m2 was associated with impaired flexibility, vincristine dose ≥39 mg/m2 with peripheral neuropathy, glucocorticoid (prednisone equivalent) dose ≥8000 mg/m2 with hand weakness, and intrathecal methotrexate dose ≥225 mg with dorsiflexion weakness. Physical inactivity was associated with hand weakness and decreased exercise capacity. Smoking was associated with peripheral neuropathy. Elimination of CRT from ALL therapy has improved, but not eliminated, body-composition outcomes. Survivors remain at risk for impaired fitness. PMID:25814529

  16. Influence of time scale on performance of a psychrometric energy balance method to estimate precipitation phase

    NASA Astrophysics Data System (ADS)

    Harder, P.; Pomeroy, J. W.

    2012-12-01

    Precipitation phase determination is fundamental to estimating catchment hydrological response to precipitation in cold regions and is especially variable over time and space in mountains. Hydrological methods to estimate phase are predominantly calibrated, depend on air temperature and use daily time steps. Air temperature is not physically related to phase and precipitation events are very dynamic, adding significant uncertainty to the use of daily air temperature indices to estimate phase. Data for this study comes from high quality, high temporal resolution precipitation phase and meteorological observations at multiple elevations in a small Canadian Rockies catchment, the Marmot Creek Research Basin, from 2005 to 2012. The psychrometric energy balance of a falling hydrometeor, requiring air temperature and humidity observations, was employed to examine precipitation phase with respect to meteorological conditions via calculation of a hydrometeor temperature. The hydrometeor temperature-precipitation phase relationship was used to quantify temporal scaling in phase observations and to develop a method to estimate precipitation phase. Temporal scaling results show that the transition range of the distribution of hydrometeor temperatures associated with mixed rainfall and snowfall decreases with decreasing time interval. The amount of precipitation also has an influence as larger events lead to smaller transition ranges across all time scales. The uncertainty of the relationship between the hydrometeor temperature and phase was quantified and degrades significantly with an increase in time interval. The errors associated with the 15 minute and hourly intervals are small. Comparisons with other methods indicate that the psychrometric energy balance method performs much better than air temperature methods and that this improvement increases with decreasing time interval. These findings suggest that the physically based psychrometric method, employed on sub

  17. Estimating Agricultural Water Use using the Operational Simplified Surface Energy Balance Evapotranspiration Estimation Method

    NASA Astrophysics Data System (ADS)

    Forbes, B. T.

    2015-12-01

    Due to the predominantly arid climate in Arizona, access to adequate water supply is vital to the economic development and livelihood of the State. Water supply has become increasingly important during periods of prolonged drought, which has strained reservoir water levels in the Desert Southwest over past years. Arizona's water use is dominated by agriculture, consuming about seventy-five percent of the total annual water demand. Tracking current agricultural water use is important for managers and policy makers so that current water demand can be assessed and current information can be used to forecast future demands. However, many croplands in Arizona are irrigated outside of areas where water use reporting is mandatory. To estimate irrigation withdrawals on these lands, we use a combination of field verification, evapotranspiration (ET) estimation, and irrigation system qualification. ET is typically estimated in Arizona using the Modified Blaney-Criddle method which uses meteorological data to estimate annual crop water requirements. The Modified Blaney-Criddle method assumes crops are irrigated to their full potential over the entire growing season, which may or may not be realistic. We now use the Operational Simplified Surface Energy Balance (SSEBop) ET data in a remote-sensing and energy-balance framework to estimate cropland ET. SSEBop data are of sufficient resolution (30m by 30m) for estimation of field-scale cropland water use. We evaluate our SSEBop-based estimates using ground-truth information and irrigation system qualification obtained in the field. Our approach gives the end user an estimate of crop consumptive use as well as inefficiencies in irrigation system performance—both of which are needed by water managers for tracking irrigated water use in Arizona.

  18. Effects of chronic exposure to radiofrequency electromagnetic fields on energy balance in developing rats.

    PubMed

    Pelletier, Amandine; Delanaud, Stéphane; Décima, Pauline; Thuroczy, Gyorgy; de Seze, René; Cerri, Matteo; Bach, Véronique; Libert, Jean-Pierre; Loos, Nathalie

    2013-05-01

    The effects of radiofrequency electromagnetic fields (RF-EMF) on the control of body energy balance in developing organisms have not been studied, despite the involvement of energy status in vital physiological functions. We examined the effects of chronic RF-EMF exposure (900 MHz, 1 V m(-1)) on the main functions involved in body energy homeostasis (feeding behaviour, sleep and thermoregulatory processes). Thirteen juvenile male Wistar rats were exposed to continuous RF-EMF for 5 weeks at 24 °C of air temperature (T a) and compared with 11 non-exposed animals. Hence, at the beginning of the 6th week of exposure, the functions were recorded at T a of 24 °C and then at 31 °C. We showed that the frequency of rapid eye movement sleep episodes was greater in the RF-EMF-exposed group, independently of T a (+42.1 % at 24 °C and +31.6 % at 31 °C). The other effects of RF-EMF exposure on several sleep parameters were dependent on T a. At 31 °C, RF-EMF-exposed animals had a significantly lower subcutaneous tail temperature (-1.21 °C) than controls at all sleep stages; this suggested peripheral vasoconstriction, which was confirmed in an experiment with the vasodilatator prazosin. Exposure to RF-EMF also increased daytime food intake (+0.22 g h(-1)). Most of the observed effects of RF-EMF exposure were dependent on T a. Exposure to RF-EMF appears to modify the functioning of vasomotor tone by acting peripherally through α-adrenoceptors. The elicited vasoconstriction may restrict body cooling, whereas energy intake increases. Our results show that RF-EMF exposure can induce energy-saving processes without strongly disturbing the overall sleep pattern.

  19. Energy balance and canopy conductance of a boreal aspen forest: Partitioning overstory and understory components

    NASA Astrophysics Data System (ADS)

    Blanken, P. D.; Black, T. A.; Yang, P. C.; Neumann, H. H.; Nesic, Z.; Staebler, R.; den Hartog, G.; Novak, M. D.; Lee, X.

    1997-12-01

    The energy balance components were measured throughout most of 1994 in and above a southern boreal aspen (Populus tremuloides Michx.) forest (53.629°N 106.200°W) with a hazelnut (Corylus cornuta Marsh.) understory as part of the Boreal Ecosystem-Atmosphere Study. The turbulent fluxes were measured at both levels using the eddy-covariance technique. After rejection of suspect data due to instationarity or inhomogeneity, occasional erratic behavior in turbulent fluxes and lack of energy balance closure led to a recalculation of the fluxes of sensible and latent heat using their ratio and the available energy. The seasonal development in leaf area was reflected in a strong seasonal pattern of the energy balance. Leaf growth began during the third week of May with a maximum forest leaf area index of 5.6 m2 m-2 reached by mid-July. During the full-leaf period, aspen and hazelnut accounted for approximately 40 and 60% of the forest leaf area, respectively. Sensible heat was the dominant consumer of forest net radiation during the preleaf period, while latent heat accounted for the majority of forest net radiation during the leafed period. Hazelnut transpiration accounted for 25% of the forest transpiration during the summer months. During the full-leaf period (June 1 to September 7) daytime dry-canopy mean aspen and hazelnut canopy conductances were 330 mmol m-2 s-1 (8.4 mm s-1) (70% of the total forest conductance) and 113 mmol m-2 s-1 (2.9 mm s-1) (24% of the total forest conductance), respectively. Maximum aspen and hazelnut canopy conductances were 1200 mmol m-2 s-1 (30 mm s-1) and 910 mmol m-2 s-1 (23 mm s-1 ), respectively, and maximum stomatal conductances were 490 mmol m-2 s-1 (12.5 mm s-1) and 280 mmol m-2 s-1 (7 m s-1), aspen and hazelnut, respectively. Both species showed a decrease in canopy conductance as the saturation deficit increased and both showed an increase in canopy conductance as the photosynthetic active radiation increased. There was a linear

  20. STIR Proposal For Research Area 2.1.2 Surface Energy Balance: Transient Soil Density Impacts Land Surface Characteristics and Characterization

    DTIC Science & Technology

    2015-12-22

    accumulated solar energy . The soil surface boundary condition was determined by the calculated surface energy balance and the observed precipitation. The...properties, and ii) evaluate impact of changing soil density on surface energy balance and heat and water transfer. Six soil properties were...2015 Approved for Public Release; Distribution Unlimited Final Report: STIR Proposal For Research Area 2.1.2 Surface Energy Balance: Transient Soil

  1. Analytical study of the energy rate balance equation for the magnetospheric storm-ring current

    NASA Astrophysics Data System (ADS)

    Clúa de Gonzalez, A. L.; Gonzalez, W. D.

    1998-11-01

    We present some results of the analytical integration of the energy rate balance equation, assuming that the input energy rate is proportional to the azimuthal interplanetary electric field, Ey, and can be described by simple rectangular or triangular functions, as approximations to the frequently observed shapes of Ey, especially during the passage of magnetic clouds. The input function is also parametrized by a reconnection-transfer efficiency factor (which is assumed to vary between 0.1 and 1). Our aim is to solve the balance equation and derive values for the decay parameter compatible with the observed Dst peak values. To facilitate the analytical integration we assume a constant value for through the main phase of the storm. The model is tested for two isolated and well-monitored intense storms. For these storms the analytical results are compared to those obtained by the numerical integration of the balance equation, based on the interplanetary data collected by the ISEE-3 satellite, with the values parametrized close to those obtained by the analytical study. From the best fit between this numerical integration and the observed Dst the most appropriate values of are then determined. Although we specifically focus on the main phase of the storms, this numerical integration has been also extended to the recovery phase by an independent adjust. The results of the best fit for the recovery phase show that the values of may differ drastically from those corresponding to the main phase. The values of the decay parameter for the main phase of each event, m, are found to be very sensitive to the adopted efficiency factor, , decreasing as this factor increases. For the recovery phase, which is characterized by very low values of the power input, the response function becomes almost independent of the value of and the resulting values for the decay time parameter, r, do not vary greatly as varies

  2. How Many Facets are Needed to Represent the Surface Energy Balance of an Urban Area?

    NASA Astrophysics Data System (ADS)

    Porson, Aurore; Harman, Ian N.; Bohnenstengel, Sylvia I.; Belcher, Stephen E.

    2009-07-01

    We investigate the question of how many facets are needed to represent the energy balance of an urban area by developing simplified 3-, 2- and 1-facet versions of a 4-facet energy balance model of two-dimensional streets and buildings. The 3-facet model simplifies the 4-facet model by averaging over the canyon orientation, which results in similar net shortwave and longwave balances for both wall facets, but maintains the asymmetry in the heat fluxes within the street canyon. For the 2-facet model, on the assumption that the wall and road temperatures are equal, the road and wall facets can be combined mathematically into a single street-canyon facet with effective values of the heat transfer coefficient, albedo, emissivity and thermodynamic properties, without further approximation. The 1-facet model requires the additional assumption that the roof temperature is also equal to the road and wall temperatures. Idealised simulations show that the geometry and material properties of the walls and road lead to a large heat capacity of the combined street canyon, whereas the roof behaves like a flat surface with low heat capacity. This means that the magnitude of the diurnal temperature variation of the street-canyon facets are broadly similar and much smaller than the diurnal temperature variation of the roof facets. Consequently, the approximation that the street-canyon facets have similar temperatures is sound, and the road and walls can be combined into a single facet. The roof behaves very differently and a separate roof facet is required. Consequently, the 2-facet model performs similarly to the 4-facet model, while the 1-facet model does not. The models are compared with previously published observations collected in Mexico City. Although the 3- and 2-facet models perform better than the 1-facet model, the present models are unable to represent the phase of the sensible heat flux. This result is consistent with previous model comparisons, and we argue that this

  3. Assessment of a dry and a wet route for the production of biofuels from microalgae: energy balance analysis.

    PubMed

    Xu, Lixian; Wim Brilman, Derk W F; Withag, Jan A M; Brem, Gerrit; Kersten, Sascha

    2011-04-01

    In this study, the energy balance of two microalgae-to-biofuel concepts, one via a so called "dry route" (oil extraction from dried algae) and one via a "wet route" (oil extraction in the water phase), are assessed. Both routes are intended to convert the chemical energy contained in the microalgae into high-value biofuels with minimal fossil energy consumption. The analysis shows that the drying process in the dry route and the oil extraction process in the wet route consume a significant amount of energy. By coupling waste heat from a nearby power plant to the process, the energy balance can be improved and a potential fossil energy ratio (FER) up to 2.38 and 1.82 can be reached for the dry and wet route, respectively. The results indicate that based on current available technologies, the dry route has higher FER and the wet route has more potential in producing high valuable biofuels.

  4. Uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model at multiple flux tower sites

    NASA Astrophysics Data System (ADS)

    Chen, Mingshi; Senay, Gabriel B.; Singh, Ramesh K.; Verdin, James P.

    2016-05-01

    Evapotranspiration (ET) is an important component of the water cycle - ET from the land surface returns approximately 60% of the global precipitation back to the atmosphere. ET also plays an important role in energy transport among the biosphere, atmosphere, and hydrosphere. Current regional to global and daily to annual ET estimation relies mainly on surface energy balance (SEB) ET models or statistical and empirical methods driven by remote sensing data and various climatological databases. These models have uncertainties due to inevitable input errors, poorly defined parameters, and inadequate model structures. The eddy covariance measurements on water, energy, and carbon fluxes at the AmeriFlux tower sites provide an opportunity to assess the ET modeling uncertainties. In this study, we focused on uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model for ET estimation at multiple AmeriFlux tower sites with diverse land cover characteristics and climatic conditions. The 8-day composite 1-km MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) was used as input land surface temperature for the SSEBop algorithms. The other input data were taken from the AmeriFlux database. Results of statistical analysis indicated that the SSEBop model performed well in estimating ET with an R2 of 0.86 between estimated ET and eddy covariance measurements at 42 AmeriFlux tower sites during 2001-2007. It was encouraging to see that the best performance was observed for croplands, where R2 was 0.92 with a root mean square error of 13 mm/month. The uncertainties or random errors from input variables and parameters of the SSEBop model led to monthly ET estimates with relative errors less than 20% across multiple flux tower sites distributed across different biomes. This uncertainty of the SSEBop model lies within the error range of other SEB models, suggesting systematic error or bias of the SSEBop model is within the

  5. Surface Energy Balance Measurements Above an Exurban Residential Neighbourhood of Kansas City, Missouri

    NASA Astrophysics Data System (ADS)

    Balogun, Ahmed A.; Adegoke, Jimmy O.; Vezhapparambu, Sajith; Mauder, Matthias; McFadden, Joseph P.; Gallo, Kevin

    2009-12-01

    Previous measurements of urban energy balances generally have been limited to densely built, central city sites and older suburban locations with mature tree canopies that are higher than the height of the buildings. In contrast, few data are available for the extensive, open vegetated types typical of low-density residential areas that have been newly converted from rural land use. We made direct measurements of surface energy fluxes using the eddy-covariance technique at Greenwood, a recently developed exurban neighbourhood near Kansas City, Missouri, USA, during an intensive field campaign in August 2004. Energy partitioning was dominated by the latent heat flux under both cloudy and near clear-sky conditions. The mean daytime Bowen ratio ( β) values were 0.46, 0.48, and 0.47 respectively for the cloudy, near clear-sky and all-sky conditions. Net radiation ( R n ) increased rapidly from dawn (-34 and -58W m-2) during the night to reach a maximum (423 and 630W m-2) after midday for cloudy and near clear-sky conditions respectively. Mean daytime values were 253 and 370W m-2, respectively for the cloudy and near clear-sky conditions, while mean daily values were 114 for cloudy and 171W m-2 for near clear-sky conditions, respectively. Midday surface albedo values were 0.25 and 0.24 for the cloudy and near clear-sky conditions, respectively. The site exhibited an angular dependence on the solar elevation angle, in contrast to previous observations over urban and suburban areas, but similar to vegetated surfaces. The latent heat flux ( Q E ), sensible heat flux ( Q H ), and the residual heat storage Δ Q s terms accounted for between 46-58%, 21-23%, and 18-31% of R n , respectively, for all-sky conditions and time averages. The observed albedo, R n , and Q E values are higher than the values that have been reported for suburban areas with high summer evapotranspiration rates in North America. These results suggest that the rapidly growing residential areas at the

  6. Uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model at multiple flux tower sites

    USGS Publications Warehouse

    Chen, Mingshi; Senay, Gabriel B.; Singh, Ramesh K.; Verdin, James P.

    2016-01-01

    Evapotranspiration (ET) is an important component of the water cycle – ET from the land surface returns approximately 60% of the global precipitation back to the atmosphere. ET also plays an important role in energy transport among the biosphere, atmosphere, and hydrosphere. Current regional to global and daily to annual ET estimation relies mainly on surface energy balance (SEB) ET models or statistical and empirical methods driven by remote sensing data and various climatological databases. These models have uncertainties due to inevitable input errors, poorly defined parameters, and inadequate model structures. The eddy covariance measurements on water, energy, and carbon fluxes at the AmeriFlux tower sites provide an opportunity to assess the ET modeling uncertainties. In this study, we focused on uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model for ET estimation at multiple AmeriFlux tower sites with diverse land cover characteristics and climatic conditions. The 8-day composite 1-km MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) was used as input land surface temperature for the SSEBop algorithms. The other input data were taken from the AmeriFlux database. Results of statistical analysis indicated that the SSEBop model performed well in estimating ET with an R2 of 0.86 between estimated ET and eddy covariance measurements at 42 AmeriFlux tower sites during 2001–2007. It was encouraging to see that the best performance was observed for croplands, where R2 was 0.92 with a root mean square error of 13 mm/month. The uncertainties or random errors from input variables and parameters of the SSEBop model led to monthly ET estimates with relative errors less than 20% across multiple flux tower sites distributed across different biomes. This uncertainty of the SSEBop model lies within the error range of other SEB models, suggesting systematic error or bias of the SSEBop model is within

  7. Entrainment of the human circadian pacemaker to longer-than-24-h days

    PubMed Central

    Gronfier, Claude; Wright, Kenneth P.; Kronauer, Richard E.; Czeisler, Charles A.

    2007-01-01

    Entrainment of the circadian pacemaker to the light:dark cycle is necessary for rhythmic physiological functions to be appropriately timed over the 24-h day. Nonentrainment results in sleep, endocrine, and neurobehavioral impairments. Exposures to intermittent bright light pulses have been reported to phase shift the circadian pacemaker with great efficacy. Therefore, we tested the hypothesis that a modulated light exposure (MLE) with bright light pulses in the evening would entrain subjects to a light:dark cycle 1 h longer than their own circadian period (τ). Twelve subjects underwent a 65-day inpatient study. Individual subject's circadian period was determined in a forced desynchrony protocol. Subsequently, subjects were released into 30 longer-than-24-h days (daylength of τ + 1 h) in one of three light:dark conditions: (i) ≈25 lux; (ii) ≈100 lux; and (iii) MLE: ≈25 lux followed by ≈100 lux, plus two 45-min bright light pulses of ≈9,500 lux near the end of scheduled wakefulness. We found that lighting levels of ≈25 lux were insufficient to entrain all subjects tested. Exposure to ≈100 lux was sufficient to entrain subjects, although at a significantly wider phase angle compared with baseline. Exposure to MLE was able to entrain the subjects to the imposed sleep–wake cycles but at a phase angle comparable to baseline. These results suggest that MLE can be used to entrain the circadian pacemaker to non-24-h days. The implications of these findings are important because they could be used to treat circadian misalignment associated with space flight and circadian rhythm sleep disorders such as shift-work disorder. PMID:17502598

  8. Effect of energy balance profiles on metabolic and reproductive response in Holstein and Swedish Red cows.

    PubMed

    Ntallaris, T; Humblot, P; Båge, R; Sjunnesson, Y; Dupont, J; Berglund, B

    2017-03-01

    This study examined the effect of two feeding levels during the antepartum and postpartum period on reproductive performance and blood metabolites (glucose, non-esterified fatty acids (NEFA), insulin) in primiparous Holstein and Swedish Red (SRB) cows, in order to identify possible differences in the way these breeds respond to negative energy balance after calving. A total of 44 cows (22 Holstein, 22 SRB) kept in a loose housing system were included in the study. The control group (HE, n = 23) was fed a diet for high-producing cows (target 35 kg/d energycorrected milk, ECM). A lower feeding intensity (LE, n = 21) was achieved by giving -50% concentrate to target 25 kg/d ECM. Diets were implemented 30 days before expected calving and the cows were monitored for 120 days postpartum. Milk yield and composition, dry matter intake (DMI), live body weight and body condition score (BCS) were assessed to calculate the weekly energy balance (residual feed intake). Blood sampling started before diet implementation and was repeated every 2 weeks until Day 60 postpartum and then once monthly until Day 120. Plasma was kept at -20 °C until analysis for glucose, insulin and NEFA concentrations. Mixed linear models were used to analyse data (SAS 9.3; PROC MIXED). Holstein cows had lower mean energy balance than SRB cows (-4.7 ± 1.4 and -0.9 ± 1.4 MJ, respectively; p = 0.05). SRB cows had higher (p<0.001) BCS (3.3 ± 0.1) than Holstein cows (2.7 ± 0.1) and also higher plasma glucose concentrations from Day -30 to Day 120 relative to parturition (4.1 ± 0.1 and 4.2 ± 0.1 log ; mg/100 ml, respectively; p < 0.05). Overall, breed or diet had no effect on NEFA blood plasma concentrations. However, plasma NEFA concentration levels tended to be higher (p = 0.09) in SRB cows than in Holsteins at Day -14 before calving, indicating higher mobilisation of lipid from adipose tissue already before calving. In contrast, Holstein cows had higher NEFA at Day 14

  9. Surface energy balances of three general circulation models: Current climate and response to increasing atmospheric CO{sub 2}

    SciTech Connect

    Gutowski, W.J.; Gutzler, D.S.; Portman, D.; Wang, W.C.

    1988-04-01

    The surface energy balance simulated by state-of-the-art general circulation models at GFDL, GISS and NCAR for climates with current levels of atmospheric CO{sub 2} concentration (control climate) and with twice the current levels. The work is part of an effort sponsored by the US Department of Energy to assess climate simulations produced by these models. The surface energy balance enables us to diagnose differences between models in surface temperature climatology and sensitivity to doubling CO{sub 2} in terms of the processes that control surface temperature. Our analysis compares the simulated balances by averaging the fields of interest over a hierarchy of spatial domains ranging from the entire globe down to regions a few hundred kilometers across.

  10. Surface energy balances of three general circulation models: Current climate and response to increasing atmospheric CO[sub 2

    SciTech Connect

    Gutowski, W.J.; Gutzler, D.S.; Portman, D.; Wang, W.C.

    1988-04-01

    The surface energy balance simulated by state-of-the-art general circulation models at GFDL, GISS and NCAR for climates with current levels of atmospheric CO[sub 2] concentration (control climate) and with twice the current levels. The work is part of an effort sponsored by the US Department of Energy to assess climate simulations produced by these models. The surface energy balance enables us to diagnose differences between models in surface temperature climatology and sensitivity to doubling CO[sub 2] in terms of the processes that control surface temperature. Our analysis compares the simulated balances by averaging the fields of interest over a hierarchy of spatial domains ranging from the entire globe down to regions a few hundred kilometers across.

  11. First results from the International Urban Energy Balance Model Comparison: Model Complexity

    NASA Astrophysics Data System (ADS)

    Blackett, M.; Grimmond, S.; Best, M.

    2009-04-01

    A great variety of urban energy balance models has been developed. These vary in complexity from simple schemes that represent the city as a slab, through those which model various facets (i.e. road, walls and roof) to more complex urban forms (including street canyons with intersections) and features (such as vegetation cover and anthropogenic heat fluxes). Some schemes also incorporate detailed representations of momentum and energy fluxes distributed throughout various layers of the urban canopy layer. The models each differ in the parameters they require to describe the site and the in demands they make on computational processing power. Many of these models have been evaluated using observational datasets but to date, no controlled comparisons have been conducted. Urban surface energy balance models provide a means to predict the energy exchange processes which influence factors such as urban temperature, humidity, atmospheric stability and winds. These all need to be modelled accurately to capture features such as the urban heat island effect and to provide key information for dispersion and air quality modelling. A comparison of the various models available will assist in improving current and future models and will assist in formulating research priorities for future observational campaigns within urban areas. In this presentation we will summarise the initial results of this international urban energy balance model comparison. In particular, the relative performance of the models involved will be compared based on their degree of complexity. These results will inform us on ways in which we can improve the modelling of air quality within, and climate impacts of, global megacities. The methodology employed in conducting this comparison followed that used in PILPS (the Project for Intercomparison of Land-Surface Parameterization Schemes) which is also endorsed by the GEWEX Global Land Atmosphere System Study (GLASS) panel. In all cases, models were run

  12. Acute effects of mustard, horseradish, black pepper and ginger on energy expenditure, appetite, ad libitum energy intake and energy balance in human subjects.

    PubMed

    Gregersen, N T; Belza, A; Jensen, M G; Ritz, C; Bitz, C; Hels, O; Frandsen, E; Mela, D J; Astrup, A

    2013-02-14

    Chilli peppers have been shown to enhance diet-induced thermogenesis (DIT) and reduce energy intake (EI) in some studies, but there are few data on other pungent spices. The primary aim of the present study was to test the acute effects of black pepper (pepper), ginger, horseradish and mustard in a meal on 4 h postprandial DIT. The secondary aim was to examine the effects on subjective appetite measures, ad libitum EI and energy balance. In a five-way placebo-controlled, single-blind, cross-over trial, twenty-two young (age 24·9 (SD 4·6) years), normal-weight (BMI 21·8 (SD 2·1) kg/m²) males were randomly assigned to receive a brunch meal with either pepper (1·3 g), ginger (20 g), horseradish (8·3 g), mustard (21 g) or no spices (placebo). The amounts of spices were chosen from pre-testing to make the meal spicy but palatable. No significant treatment effects were observed on DIT, but mustard produced DIT, which tended to be larger than that of placebo (14 %, 59 (SE 3) v. 52 (SE 2) kJ/h, respectively, P=0·08). No other spice induced thermogenic effects approaching statistical significance. Subjective measures of appetite (P>0·85), ad libitum EI (P=0·63) and energy balance (P=0·67) also did not differ between the treatments. Finally, horseradish decreased heart rate (P=0·048) and increased diastolic blood pressure (P= 0·049) compared with placebo. In conclusion, no reliable treatment effects on appetite, EI or energy balance were observed, although mustard tended to be thermogenic at this dose. Further studies should explore the possible strength and mechanisms of the potential thermogenic effect of mustard actives, and potential enhancement by, for example, combinations with other food components.

  13. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    PubMed

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream.

  14. Energy and water balance studies of a snow cover during snowmelt period at a high arctic site

    NASA Astrophysics Data System (ADS)

    Bruland, O.; Maréchal, D.; Sand, K.; Killingtveit, Å.

    The predicted global warming is supposed to have an enhanced effect on the arctic regions. How this will influence the water, carbon dioxide and methane balances in the European arctic tundra is the objective of the EU-funded project ``Understanding Land Surface Physical Processes in the Arctic'' (LAPP), to which where SINTEF is one of several contributors. The snow cover is one of the limiting factors for these exchange processes and knowledge of how it behaves and will behave under a different climate is important. Data collected for water and energy balance studies in an area close to Ny-Ålesund at 79°N at Svalbard are the basis of this study. Measurements during the ablation periods since 1992 show an average air temperature for the periods of 2.1°C, an average incoming shorwave radiation of 230W/m2 and an average measured runoff intensity of 14mm/day with a maximum of 68mm/day. Three models of different complexity are tested in order to simulate the water and energy balance of a snow cover on the arctic tundra. The three models are: a complex numerical model (CROCUS), a simple energy balance model and a temperature index model. The simulations were carried out for the melt periods in 1992 and 1996 as these two periods represent very different meteorological conditions. The results of these simulations exposed weaknesses in all the models. The energy balance model lacks calculation of cold content in the snowpack. This influences both the outgoing longwave radiation and the timing of the melt. Due to the effect of compensating errors in the simulations, CROCUS performed better than the simple energy balance model but also this model has problems with the simulation of outgoing longwave radiation. The temperature index model does not perform well for snowmelt studies in regions were radiation is the main driving energy source for the melt.

  15. Energy balance, metabolism, hydration, and performance during strenuous hill walking: the effect of age.

    PubMed

    Ainslie, P N; Campbell, I T; Frayn, K N; Humphreys, S M; MacLaren, D P M; Reilly, T; Westerterp, K R

    2002-08-01

    We aimed to examine the effect of age on energy balance, metabolism, hydration, and performance during 10 days of strenuous hill walking. Seventeen male subjects were divided into two groups according to their age. The nine subjects in group 1 constituted the younger group (age 24 +/- 3 yr), whereas eight older subjects were in group 2 (age 56 +/- 3 yr). Both groups completed 10 consecutive days of high-intensity hill walking. Mean (range) daily walking distances and ascent were 21 km (10-35 km) and 1,160 m (800-2,540 m), respectively. Energy intake was calculated from weighed food intake, and energy expenditure was measured by the doubly labeled water method. Blood and urine were sampled on alternative days to determine any changes in metabolism and hydration during the 10 days. Subjects also completed a battery of tests that included muscular strength (handgrip), jump performance, cognitive processing time, and flexibility. The younger group remained hydrated, whereas the older group became progressively dehydrated, indicated by a near twofold increase in urine osmolality concentration on day 11. This increased urine osmolality in the older group was highly correlated with impairment in vertical-jump performance (r = -0.86; P < 0.05) and decreased cognitive processing time (r = 0.79; P < 0.05). Despite energy expenditure of approximately 21 MJ/day, body mass was well maintained in both groups. Both groups displayed a marked increase in fat mobilization, reflected in significantly lowered prewalk insulin concentrations and elevated postwalk glycerol and nonesterified fatty acid concentrations. Despite the dehydration and impaired performance in the older group, blood glucose concentrations were well maintained in both groups, probably mediated via the increased mobilization of fat.

  16. Bioenergy from stillage anaerobic digestion to enhance the energy balance ratio of ethanol production.

    PubMed

    Fuess, Lucas Tadeu; Garcia, Marcelo Loureiro

    2015-10-01

    The challenges associated with the availability of fossil fuels in the past decades intensified the search for alternative energy sources, based on an ever-increasing demand for energy. In this context, the application of anaerobic digestion (AD) as a core treatment technology in industrial plants should be highlighted, since this process combines the pollution control of wastewaters and the generation of bioenergy, based on the conversion of the organic fraction to biogas, a methane-rich gaseous mixture that may supply the energetic demands in industrial plants. In this context, this work aimed at assessing the energetic potential of AD applied to the treatment of stillage, the main wastewater from ethanol production, in an attempt to highlight the improvements in the energy balance ratio of ethanol by inserting the heating value of methane as a bioenergy source. At least 5-15% of the global energy consumption in the ethanol industry could be supplied by the energetic potential of stillage, regardless the feedstock (i.e. sugarcane, corn or cassava). The association between bagasse combustion and stillage anaerobic digestion in sugarcane-based distilleries could provide a bioenergy surplus of at least 130% of the total fossil fuel input into the ethanol plant, considering only the energy from methane. In terms of financial aspects, the economic gains could reach US$ 0.1901 and US$ 0.0512 per liter of produced ethanol, respectively for molasses- (Brazil) and corn-based (EUA) production chains. For large-scale (∼1000 m(3)EtOH per day) Brazilian molasses-based plants, an annual economic gain of up to US$ 70 million could be observed. Considering the association between anaerobic and aerobic digestion, for the scenarios analyzed, at least 25% of the energetic potential of stillage would be required to supply the energy consumption with aeration, however, more suitable effluents for agricultural application could be produced. The main conclusion from this work

  17. Hurricane disturbance and recovery of carbon and energy balance in a tidal mangrove forest

    NASA Astrophysics Data System (ADS)

    Barr, J. G.; Engel, V.; Fuentes, J. D.; Smith, T.

    2009-12-01

    The goal of this presentation is to determine mangrove ecosystem function following a disturbance. Hurricane Wilma made landfall as a Category 3 storm along the western coast of the Florida Everglades in October 2005. The storm deposited large amounts of marine calcitic sediments. At a site 2 km inland from the center of landfall, 5 cm of sediments were deposited, and 30% of mature trees were defoliated and killed. At this site, tower based measurements of carbon dioxide eddy covariance and energy balance were started in 2004. Several years of repeated measurements of tree basal area, litterfall, root turnover, and peat surface elevations also pre-date the storm. Measurements resumed in 2006, providing an opportunity to examine the effects of hurricane disturbance on coastal ecosystem functioning. Following defoliation sensible heating decreased and latent heating increased. Reductions in sensible heating are attributed to decreased energy exchange at the forest crown and increased solar energy reaching the peat surface. Increases in latent heating are attributed to increased turbulent transport of latent heat fluxes from the saturated soil and water beneath the forest. Soil temperature and soil heat fluxes increased after the storm. Reductions in net ecosystem carbon assimilation rates (NEE) are apparent 4 years after the storm, though the rates are now approaching pre-storm values. The increased soil temperature following the storm presumably led to increased soil respiration which, along with the tree mortality, branch loss, and defoliation, explained the decreases in ecosystem-level carbon assimilation rates following the storm. Minimum half-hourly NEE values reached -25 μmol m-2 s-1 and -22 μmol m-2 s-1 before and after the storm, respectively. Daytime ecosystem respiration rates (Re) estimated using the intercept of light-response curves increased by an average of 1.2 μmol m-2 s-1 at a reference temperature of 20 oC during low tide periods. Nightime Re at

  18. Estimating evapotranspiration with thermal UAV data and two source energy balance models

    NASA Astrophysics Data System (ADS)

    Hoffmann, H.; Nieto, H.; Jensen, R.; Guzinski, R.; Zarco-Tejada, P. J.; Friborg, T.

    2015-08-01

    Estimating evapotranspiration is important when managing water resources and cultivating crops. Evapotranspiration can be estimated using land surface heat flux models and remotely sensed land surface temperatures (LST) which recently have become obtainable in very high resolution using Unmanned Aerial Vehicles (UAVs). Very high resolution LST can give insight into e.g. distributed crop conditions within cultivated fields. In this study evapotranspiration is estimated using LST retrieved with a UAV and the physically-based, two source energy balance models: the Priestley-Taylor TSEB (TSEB-PT) and the Dual-Temperature-Difference (DTD). A fixed-wing UAV was flown over a barley field in western Denmark during the spring and summer in 2014 and retrieved images of LST is successfully processed into thermal mosaics which serve as model input for both TSEB-PT and DTD. The aim is to assess whether a lightweight thermal camera mounted on a UAV is able to provide data of sufficient quality to obtain high spatial and temporal resolution surface