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Energy balance

Y Tao, S J Goh, H M J Bastiaens, P J M van der Slot, S G Biedron, S V Milton, K-J Boller
We present a model for quasi-phase matching (QPM) in high-order harmonic generation (HHG). Using a one-dimensional description, we analyze the time-dependent, ultrafast wave-vector balance to calculate the on-axis harmonic output versus time, from which we obtain the output pulse energy. Considering, as an example, periodically patterned argon gas, as may be provided with a grid in a cluster jet, we calculate the harmonic output during different time intervals within the drive laser pulse duration. We find that identifying a suitable single spatial period is not straightforward due to the complex and ultrafast plasma dynamics that underlies HHG at increased intensities...
February 20, 2017: Optics Express
George A Khoury, James Smadbeck, Chris A Kieslich, Alexandra J Koskosidis, Yannis A Guzman, Phanourios Tamamis, Christodoulos A Floudas
Protein structure refinement is the challenging problem of operating on any protein structure prediction to improve its accuracy with respect to the native structure in a blind fashion. Although many approaches have been developed and tested during the last four CASP experiments, a majority of the methods continue to degrade models rather than improve them. Princeton_TIGRESS (Khoury et al., Proteins, 2014) was developed previously and utilizes separate sampling and selection stages involving Monte Carlo and molecular dynamics simulations and classification using an SVM predictor...
February 27, 2017: Proteins
Peter J Snyder, David L Kopperdahl, Alisa J Stephens-Shields, Susan S Ellenberg, Jane A Cauley, Kristine E Ensrud, Cora E Lewis, Elizabeth Barrett-Connor, Ann V Schwartz, David C Lee, Shalender Bhasin, Glenn R Cunningham, Thomas M Gill, Alvin M Matsumoto, Ronald S Swerdloff, Shehzad Basaria, Susan J Diem, Christina Wang, Xiaoling Hou, Denise Cifelli, Darlene Dougar, Bret Zeldow, Douglas C Bauer, Tony M Keaveny
Importance: As men age, they experience decreased serum testosterone concentrations, decreased bone mineral density (BMD), and increased risk of fracture. Objective: To determine whether testosterone treatment of older men with low testosterone increases volumetric BMD (vBMD) and estimated bone strength. Design, Setting, and Participants: Placebo-controlled, double-blind trial with treatment allocation by minimization at 9 US academic medical centers of men 65 years or older with 2 testosterone concentrations averaging less than 275 ng/L participating in the Testosterone Trials from December 2011 to June 2014...
February 21, 2017: JAMA Internal Medicine
Eungjin Ahn, Byeong-Su Kim
Hybrid electrodes are widely used in various energy storage and conversion devices. However, conventional fabrication methods like simple mixing allow only limited control over the internal electrode structure, and it is often difficult to elucidate the structure-property relationship among the electrode components. Taking advantage of the versatile layer-by-layer (LbL) assembly method, herein we report the preparation of electrocatalytic thin film electrodes for hydrogen evolution reaction (HER), highlighting the importance of nanoscale composition in multidimensional hybrid electrodes...
February 27, 2017: ACS Applied Materials & Interfaces
Jasper Bloemen, Régis Fichot, Joanna A Horemans, Laura S Broeckx, Melanie S Verlinden, Terenzio Zenone, Reinhart Ceulemans
Short-rotation coppice (SRC) has great potential for supplying biomass-based heat and energy, but little is known about SRC's ecological footprint, particularly its impact on the water cycle. To this end, we quantified the water use of a commercial scale poplar (Populus) SRC plantation in East Flanders (Belgium) at tree and stand level, focusing primarily on the transpiration component. First, we used the AquaCrop model and eddy covariance flux data to analyse the different components of the stand-level water balance for one entire growing season...
February 2017: Global Change Biology. Bioenergy
Tsung-Chieh Lin, Michael Hsiao
Ghrelin is a small peptide with 28 amino acids, and has been characterized as the ligand of the growth hormone secretagogue receptor (GHSR). In addition to its original function in stimulating pituitary growth hormone release, ghrelin is multifunctional which plays role in the regulation of energy balance, gastric acid release, appetite, insulin secretion, gastric motility and the turnover of gastric and intestinal mucosa. The discovery of ghrelin and GHSR expression beyond normal tissues suggests its role other than physiological function...
February 23, 2017: Biochimica et Biophysica Acta
M Duplessis, H Lapierre, D Pellerin, J-P Laforest, C L Girard
The purpose of this experiment was to gain understanding on changes in energy partitioning when folic acid and vitamin B12 supplements, alone or combined, were given by weekly intramuscular injections from 3 wk before the expected calving date until 7 wk postpartum. Twenty-four multiparous cows were assigned to 6 blocks of 4 cows each according to previous 305-d lactation yield to either 0 or 320 mg of folic acid and 0 or 10 mg of vitamin B12 in a 2 × 2 factorial arrangement. Plasma concentration of folates was increased by folic acid supplement, and this increase was greater with the combined supplement...
February 22, 2017: Journal of Dairy Science
A M Abdelatty, M E Iwaniuk, M Garcia, K M Moyes, B B Teter, P Delmonte, A K G Kadegowda, M A Tony, F F Mohamad, R A Erdman
Investigations of the temporal changes in mammary gene expression that occur during sudden diet change have been limited by the use of mammary tissue as the source of RNA because of the invasive nature of mammary biopsy procedures. However, the cytosolic crescent, present in 1% of the largest milk fat globules, contains mammary epithelial cell RNA that has become trapped between the inner and outer milk fat globule membranes during final formation and secretion of milk fat into the lumen of the mammary alveoli...
February 22, 2017: Journal of Dairy Science
David J Reiner, Elizabeth G Mietlicki-Baase, Diana R Olivos, Lauren E McGrath, Derek J Zimmer, Kieran Koch-Laskowski, Joanna Krawczyk, Christopher A Turner, Emily E Noble, Joel D Hahn, Heath D Schmidt, Scott E Kanoski, Matthew R Hayes
BACKGROUND: The pancreatic- and brain-derived hormone amylin promotes negative energy balance and is receiving increasing attention as a promising obesity therapeutic. However, the neurobiological substrates mediating amylin's effects are not fully characterized. We postulated that amylin acts in the lateral dorsal tegmental nucleus (LDTg), an understudied neural processing hub for reward and homeostatic feeding signals. METHODS: We used immunohistochemical and quantitative polymerase chain reaction analyses to examine expression of the amylin receptor complex in rat LDTg tissue...
January 10, 2017: Biological Psychiatry
Hitomi I Sano, Tamami Toki, Yasuhiro Naito, Masaru Tomita
The developmental program of the heart requires accurate regulation to ensure continuous circulation and simultaneous cardiac morphogenesis, because any functional abnormalities may progress to congenital heart malformation. Notably, energy metabolism in fetal ventricular cells is regulated in a manner that differs from adult ventricular cells: fetal cardiomyocytes generally have immature mitochondria and fetal ventricular cells show greater dependence on glycolytic ATP production. However, although various characteristics of energy metabolism in fetal ventricular cells have been reported, to our knowledge, a quantitative description of the contributions of these factors to fetal ventricular cell functions has not yet been established...
February 22, 2017: Journal of Theoretical Biology
Bin Song, Nathaniel Charest, Herbert Alexander Morriss-Andrews, Valeria Molinero, Joan-Emma Shea
The conformational states adopted by a polymer chain in water are a result of a delicate balance between intra-molecular and water-mediated interactions. Using an explicit representation of the solvent is, however, computationally expensive and it is often necessary to turn to implicit representations. We present a systematic derivation of implicit models of water and study the effect of simplifying the representation of the solvent on the conformations of hydrophobic homopolymers of varying length. Starting from the explicit coarse-grained single site mW water model, we develop an implicit solvent model that reproduces the free energy of the contact pair between two hydrophobic monomers, an implicit solvent model that captures the free energy of contact pair minima, desolvation barrier, and solvent-separated minima, and finally, we consider vacuum simulations...
February 25, 2017: Journal of Computational Chemistry
Julita Sadowska, Andrzej K Gębczyński, Marek Konarzewski
Factors affecting contribution of spontaneous physical activity (SPA; activity associated with everyday tasks) to energy balance of humans are not well understood, as it is not clear whether low activity is related to dietary habits, precedes obesity or is a result of thereof. In particular, human studies on SPA and basal metabolic rates (BMR, accounting for >50% of human energy budget) and their associations with diet composition, metabolic thrift and obesity are equivocal. To clarify these ambiguities we used a unique animal model-mice selected for divergent BMR rates (the H-BMR and L-BMR line type) presenting a 50% between-line type difference in the primary selected trait...
2017: PloS One
Tobias Wunsch, Nathalie Alexander, Josef Kröll, Thomas Stöggl, Hermann Schwameder
To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model...
2017: PloS One
Frédéric Schwenger, Endre Repasi
The knowledge of the spatial energy (or power) distribution of light beams reflected at the dynamic sea surface is of great practical interest in maritime environments. For the estimation of the light energy reflected into a specific spatial direction a lot of parameters need to be taken into account. Both whitecap coverage and its optical properties have a large impact upon the calculated value. In published literature, for applications considering vertical light propagation paths, such as bathymetric lidar, the reflectance of sea surface and whitecaps are approximated by constant values...
February 20, 2017: Applied Optics
S Rödel, F W Günthert, T Brüggemann
To demonstrate the effects of increased extraneous water on operation, purification, and energy efficiency, two wastewater treatment plants (WWTPs) have been investigated in detail under the research project 'Sealing of sewer pipes - Effects on the purification performance of WWTPs and their impact on the local water balance'. Both treatment plants, after evaluating and analyzing the measurement data and information about them, were compared in the light of existing literature and other practical investigations...
February 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Bruno Geloneze, José Carlos de Lima-Júnior, Lício A Velloso
The complexity of neural circuits that control food intake and energy balance in the hypothalamic nuclei explains some of the constraints involved in the prevention and treatment of obesity. Two major neuronal populations present in the arcuate nucleus control caloric intake and energy expenditure: one population co-expresses orexigenic agouti-related peptide (AgRP) and neuropeptide Y and the other expresses the anorexigenic anorectic neuropeptides proopiomelanocortin and cocaine- and amphetamine-regulated transcript (POMC/CART)...
February 23, 2017: Drugs
Vicente Lahera, Natalia de Las Heras, Antonio López-Farré, Walter Manucha, León Ferder
Mitochondria are essential for the maintenance of normal physiological function of tissue cells. Mitochondria are subject to dynamic processes in order to establish a control system related to survival or cell death and adaptation to changes in the metabolic environment of cells. Mitochondrial dynamics includes fusion and fission processes, biogenesis, and mitophagy. Modifications of mitochondrial dynamics in organs involved in energy metabolism such as the pancreas, liver, skeletal muscle, and white adipose tissue could be of relevance for the development of insulin resistance, obesity, and type 2 diabetes...
February 2017: Current Hypertension Reports
Julian L Seifter, Hsin-Yun Chang
BACKGROUND: Disorders of acid-base involve the complex interplay of many organ systems including brain, lungs, kidney, and liver. Compensations for acid-base disturbances within the brain are more complete, while limitations of compensations are more apparent for most systemic disorders. However, some of the limitations on compensations are necessary to survival, in that preservation of oxygenation, energy balance, cognition, electrolyte, and fluid balance are connected mechanistically...
January 2017: Kidney Diseases
Huxing Cui, Miguel López, Kamal Rahmouni
Obesity, a major risk factor for the development of diabetes mellitus, cardiovascular diseases and certain types of cancer, arises from a chronic positive energy balance that is often due to unlimited access to food and an increasingly sedentary lifestyle on the background of a genetic and epigenetic vulnerability. Our understanding of the humoral and neuronal systems that mediate the control of energy homeostasis has improved dramatically in the past few decades. However, our ability to develop effective strategies to slow the current epidemic of obesity has been hampered, largely owing to the limited knowledge of the mechanisms underlying resistance to the action of metabolic hormones such as leptin and ghrelin...
February 24, 2017: Nature Reviews. Endocrinology
Miguel Lopez
AMP-activated protein kinase (AMPK) is a cellular gauge that is activated under conditions of low energy, increasing energy production and reducing energy waste. Centrally, the AMPK pathway is a canonical route regulating energy homeostasis, by integrating peripheral signals, such as hormones and metabolites, with neuronal networks. Current evidence links hypothalamic AMPK with feeding, brown adipose tissue (BAT) thermogenesis and browning of white adipose tissue (WAT), as well as muscle metabolism, hepatic function and glucose homeostasis...
February 23, 2017: European Journal of Endocrinology
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