Energy Balance Mechanisms Research Articles

The adipose tissue melanocortin 3 receptor is targeted by ghrelin and leptin and may be a therapeutic target in obesity

ObjectiveObesity is linked to perturbations in energy balance mechanisms, including ghrelin and leptin actions at the hypothalamic circuitry of neuropeptide Y (NPY) and melanocortin. However, information about the regulation of this system in the periphery is still scarce. Our objective was to study the regulation of the NPY/melanocortin system in the adipose tissue (AT) and evaluate its therapeutic potential for obesity and type 2 diabetes. MethodsThe expression of the NPY/melanocortin receptors’ levels was assessed in the visceral AT of individuals with obesity and altered metabolism. Protein levels of these receptors were evaluated in cultured adipocytes incubated with ghrelin (30 and 100 ng/mL) and leptin (1 and 10 nM) and in the AT of an animal model with a mutation in the leptin receptor (ZSF1 rat), to understand their regulation by leptin and ghrelin. The vertical sleeve gastrectomy animal model was used to evaluate the putative therapeutic potential of the NPY/melanocortin system. ResultsIn this study, we unravelled that leptin (1 nM and 10 nM) selectively reduced the levels of NPY5R and MC3R but no other NPYR/MCRs in cultured adipocytes. In turn, acylated ghrelin (100 ng/mL) significantly increased NPY1R, but the inhibition of its receptor also abrogates MC3R levels. However, in the Lepr-deficient ZSF1 rat, both NPY5R and MC3R levels were reduced, along with other NPYRs and MCRs, suggesting that leptin resistance negatively affects NPY and melanocortin signalling. In human adipose tissue, we found a downregulation of genes encoding the NPY and melanocortin receptors in the visceral AT of individuals with obesity and insulin resistance, being correlated with genes regulating metabolic activity. Additionally, diabetic obese rats submitted to vertical sleeve gastrectomy showed increased levels of NPY, melanocortin, ghrelin, and leptin receptors in the AT, including MC3R, suggesting it may constitute a therapeutic target in obesity. ConclusionsOur results suggest that the AT NPY/melanocortin system, particularly the MC3R, may be involved in the neuroendocrine regulation of adipocyte metabolism. Altogether, our work shows MC3R is under the control of the ghrelin/leptin duo, is reduced in patients with obesity and prediabetes, and may constitute a therapeutic target in obesity.

Goat Milk Supplementation Modulates the Mitochondrial Metabolic Flexibility and Orexin-A Levels Influencing the Inflammatory Pattern in Rats.

Milk and its derivatives are included in a balanced diet of humans as excellent sources of proteins, vitamins, and essential minerals that are functional nutrients. Knowledge about the nutritional benefits or harms due to milk consumption has been expanding in recent years. We previously explored, in rodent models, the metabolic effects of isoenergetic intake of milk derived from cows, donkeys, or humans, while the impact of goat's milk intake has remained unexplored. The aim of this work was to investigate, in an animal model, the effects of dietary supplementation with goat's milk on energy homeostasis and inflammatory state, focusing on the modulation of mitochondrial functions in most metabolically active organs, such as skeletal muscle and the liver. In addition, we highlighted a link between nutrient intake, substrate metabolism, and the orexinergic system. Our results indicate that goat milk improves mitochondrial oxidative capacity and reduces inflammation and oxidative stress in both organs. Notably, goat milk lowers the circulating levels of Orexin-A, a neuropeptide that plays a crucial role in regulating peripheral energy balance and central nervous system mechanisms. These data provide the first evidence that the anti-inflammatory and antioxidant effects of goat milk are mediated by the modulation of mitochondrial functions and orexinergic signaling.

Collaborative optimization model of industrial high‐energy consumption park under green and low‐carbon transformation

AbstractUnder the background of green and low‐carbon transformation of industrial high‐energy‐consuming parks, in order to realize the coordinated development planning of energy and transportation under different peaking capacity requirements, this paper proposes a collaborative optimization model of industrial high‐energy‐consuming parks under green and low‐carbon. Firstly, by studying the energy balance mechanism between industrial load and new energy, an energy topology prior model of energy interaction in the next generation of industrial new energy power grid is constructed. Then, based on the probability characteristics of the equilibrium state of different regions in the high‐energy‐consuming industrial zone, combined with the prior knowledge of industrial load and low‐carbon power system, a collaborative development planning model of high‐energy‐consuming industrial parks is constructed. Finally, the proposed model is simulated. From the simulation results the authors can see the dynamic division model and solution algorithm of energy balance region established in this paper can effectively improve the energy balance ability of power grid, reduce peak shaving demand and use more renewable energy.

Anti-Obesity Effects of GABA in C57BL/6J Mice with High-Fat Diet-Induced Obesity and 3T3-L1 Adipocytes.

Obesity is the excessive accumulation of body fat resulting from impairment in energy balance mechanisms. In this study, we aimed to investigate the mechanism whereby GABA (γ-aminobutyric acid) prevents high-fat diet-induced obesity, and whether it induces lipolysis and browning in white adipose tissue (WAT), using high-fat diet (HFD)-fed obese mice and 3T3-L1 adipocytes. We demonstrated that GABA substantially inhibits the body mass gain of mice by suppressing adipogenesis and lipogenesis. Consistent with this result, histological analysis of WAT demonstrated that GABA decreases adipocyte size. Moreover, we show that GABA administration decreases fasting blood glucose and improves serum lipid profiles and hepatic lipogenesis in HFD-fed obese mice. Furthermore, Western blot and immunofluorescence analyses showed that GABA activates protein kinase A (PKA) signaling pathways that increase lipolysis and promote uncoupling protein 1 (UCP1)-mediated WAT browning. Overall, these results suggest that GABA exerts an anti-obesity effect via the regulation of lipid metabolism.

HP-ECD: Heuristic Prophet protocol based on energy balance,cache optimization, and asynchronous dormancy

In opportunistic networks, opportunistic routing protocols are used for nodes to forward messages, which are the core technology to realize various opportunistic network applications. However, the existing opportunistic routing protocols generally have three problems: Key nodes forwarded too many messages, resulting in unbalanced energy consumption; Delivered message still occupies the cache space of nodes, resulting in the loss of undelivered message; Nodes constantly sense their surroundings and forward messages, resulting in rapid energy depletion. To better solve these problems, this paper proposes HP-ECD: heuristic Prophet routing protocol based on energy balance, cache optimization, and asynchronous dormancy. Based on Prophet, First, the HP-ECD defines the message forwarding benefits based on multiple node attributes and message importance, to realize the energy balance mechanism of nodes. Then, the HP-ECD designs the message delivery list based on the node history information, to realize the cache optimization mechanism of nodes. Finally, the HP-ECD determines whether a node is in dormancy based on the node running status, to realize the asynchronous dormancy mechanism of nodes. Simulation results show that, compared with Epidemic, Prophet, and EC-CW, HP-ECD greatly improves the message delivery rate and average remaining energy, and reduces the routing overhead rate and average storage time.

A Modular Multilevel Converter Station With Multiple MVac Ports

Medium voltage (MV) ac/dc hybrid distribution network attracts much interest due to its high reliability, high power quality, and high compatibility with distributed generation and dc loads. As the key enablers to interconnect ac and dc grids, the converter stations usually adopt the modular multilevel converter (MMC) topology due to its superior modularity and scalability. Unlike the conventional stations that are implemented with multiple MMCs to accommodate multiple ac feeders, a novel multi-ac-port MMC station (MACP-MMC), which evolves from the MMC topology, is proposed in this paper to interconnect different ac feeders and facilitate flexible power exchange in the MV hybrid distribution network. In addition to the benefits inherited from the MMC, the proposed MACP-MMC also features easy multiport extension, bidirectional power flow adjustment, high power density and low cost. The operation principle, energy balance mechanism, and control strategies are elaborated. Finally, its effectiveness is verified by both simulation results in a 3-MVA case and experimental results obtained from a 3-kVA scaled-down lab prototype.

Exposure to Obesogenic Environments during Perinatal Development Modulates Offspring Energy Balance Pathways in Adipose Tissue and Liver of Rodent Models

Obesogenic environments such as Westernized diets, overnutrition, and exposure to glycation during gestation and lactation can alter peripheral neuroendocrine factors in offspring, predisposing for metabolic diseases in adulthood. Thus, we hypothesized that exposure to obesogenic environments during the perinatal period reprograms offspring energy balance mechanisms. Four rat obesogenic models were studied: maternal diet-induced obesity (DIO); early-life obesity induced by postnatal overfeeding; maternal glycation; and postnatal overfeeding combined with maternal glycation. Metabolic parameters, energy expenditure, and storage pathways in visceral adipose tissue (VAT) and the liver were analyzed. Maternal DIO increased VAT lipogenic [NPY receptor-1 (NPY1R), NPY receptor-2 (NPY2R), and ghrelin receptor], but also lipolytic/catabolic mechanisms [dopamine-1 receptor (D1R) and p-AMP-activated protein kinase (AMPK)] in male offspring, while reducing NPY1R in females. Postnatally overfed male animals only exhibited higher NPY2R levels in VAT, while females also presented NPY1R and NPY2R downregulation. Maternal glycation reduces VAT expandability by decreasing NPY2R in overfed animals. Regarding the liver, D1R was decreased in all obesogenic models, while overfeeding induced fat accumulation in both sexes and glycation the inflammatory infiltration. The VAT response to maternal DIO and overfeeding showed a sexual dysmorphism, and exposure to glycotoxins led to a thin-outside-fat-inside phenotype in overfeeding conditions and impaired energy balance, increasing the metabolic risk in adulthood.

Developmental thyroid hormone action on pro-opiomelanocortin-expressing cells programs hypothalamic BMPR1A depletion and brown fat activation.

Thyroid hormone excess secondary to global type 3 deiodinase (DIO3) deficiency leads to increased locomotor activity and reduced adiposity, but also to concurrent alterations in parameters of the leptin-melanocortin system that would predict obesity. To distinguish the underlying contributions to the energy balance phenotype of DIO3 deficiency, we generated mice with thyroid hormone excess targeted to pro-opiomelanocortin (POMC)-expressing cells via cell-specific DIO3 inactivation. These mice exhibit a male-specific phenotype of reduced hypothalamic Pomc expression, hyperphagia, and increased activity in brown adipose tissue, with adiposity and serum levels of leptin and thyroid hormones remained normal. These male mice also manifest a marked and widespread hypothalamic reduction in the expression of bone morphogenetic receptor 1a (BMPR1A), which has been shown to cause similar phenotypes when inactivated in POMC-expressing cells. Our results indicate that developmental overexposure to thyroid hormone in POMC-expressing cells programs energy balance mechanisms in a sexually dimorphic manner by suppressing adult hypothalamic BMPR1A expression.

A shared energy storage business model for data center clusters considering renewable energy uncertainties

The energy consumption of data centers (DCs) is on a sharp upward trend in recent years. DCs are playing an increasingly important role in demand response (DR) programs. However, the reassignment of computing tasks among DCs leads to different energy demands of different DCs. Given that the investment cost of energy storage is high, this work proposes a shared energy storage business model for the DC cluster (DCC) to improve economic benefits and promote renewable energy accommodation. Besides, an internal energy balance mechanism is set up to make full use of the complementary energy consumption characteristics of different DCs. Considering the renewable energy uncertainty, an optimization model is proposed based on the chance-constrained goal programming (CCGP). Finally, simulation results prove that the proposed energy storage business model has a positive effect on improving the economic benefits of the DCC. It also proves that for a DCC adopting the proposed internal energy balance mechanism, its total renting power can be effectively reduced and renewable energy consumption can be greatly promoted.

Sandwich-structured MXene/wood aerogel with waste heat utilization for continuous desalination

Solar-driven interfacial evaporation technology has shown promising prospect in desalination. However, the weakened energy efficiency caused by intermittent solar irradiation and salt deposition during continuous desalination process is the great obstacle in the application. Here, we report a sandwich-structured MXene/wood aerogel coupled with phase change materials (PCMs) evaporator for high-efficiency and continuous desalination. The multi-stage water transport channel of DWA and the enhanced thermal localization effect of MXene and DWA optimize the performance of the evaporator. The PCMs block as a waste heat recovery module largely reduces heat loss. Under one solar irradiation, the evaporation rate of 2.0 kg·m−2·h−1 and energy efficiency of 92.6 % are achieved. The production of fresh water can reach 15 kg·m−2·day−1. The evaporation rate under intermittent solar irradiation can also reach 1.77 kg·m−2·h−1. There is no clear decrease in evaporation performance as well as salt accumulation for 5 days of continuous evaporation. The energy balance, water transport, thermal localization and salt resistance mechanisms of solar-driven interfacial evaporation are analyzed. This work shows an excellent way to break the limitations of conventional solar interfacial evaporation and achieve stable desalination under intermittent solar irradiation.

Numerical analyses of energy balance and installation mechanisms of large-diameter tapered monopiles by impact driving

Large-diameter monopiles are widely used as the foundation to support offshore wind turbines (OWTs) in shallow coastal waters. The benefits of small-to-medium diameter tapered piles have been reported in the past. The potential use of large-diameter tapered monopiles installed by impact driving to support OWTs is thus presented, and then comparatively assessed by numerical analyses in terms of energy balance and installation mechanisms. A three-dimensional large deformation finite element (3D-LDFE) model of monopiles driven in clay was developed using a Coupled Eulerian-Lagrangian (CEL) approach. An advanced user-defined hypoplasticity clay (HC) model was employed to model undrained kaolin clay, featuring nonlinear behavior from small strain to large strain. The force-time curve defined by the operating data of a state-of-the-art hammer in the offshore industry was inputted to explicitly model impact driving. Better agreement between the measured and the simulated results was observed to validate the accuracy of the numerical model. The numerical results obtained give greater confidence to the future use of large diameter tapered monopiles for OWTs.

Research on the Application of Fracture Water to Mitigate the Thermal Imbalance of a Rock Mass Associated with the Operation of Ground-Coupled Heat Pumps

Shallow geothermal energy is a clean and effective form of energy that can overcome the problems associated with the depletion of carbon-based energy carbon emissions. Due to the special hydrogeological conditions in karst regions, the heat transfer between heat exchange boreholes and the ground formation is a complicated, multi-physical process. The abundant groundwater flow plays an important role in the heat transfer process, and even presents an opportunity to mitigate the heat imbalance during the long term operation of ground-coupled heat pumps (GCHP). In this study, both laboratorial experiments and numerical simulations were performed to analyze the mechanism that shows how fracture water impacts on heat capacity and the thermal imbalance of the energy storage rock mass. The results showed that the overall temperature fluctuation of the rock mass was reduced by the fracture water, and the temperature curve with time became gentler, which means in practice that the heat imbalance in the rock mass could be delayed. However, the temperature contour map showed that the impact of the fracture water flow was constrained in the nearby areas and decreased obviously with distance. The temperature field was also dragged along the direction of the fracture water flow. During the shutdown period, the fracture water significantly enhanced the thermal recovery ability of the rock mass. The results will assist in further understanding the mechanism of heat transfer and energy balance in a rock mass with fracture water flow. It is proposed that the U pipes should be located at zones with abundant fracture water if the construction condition permits. U pipes that are near the fractures should share more of the load or a denser layout could be possible as their heat transfer capacity is improved by the water flow.

Sexual Dimorphism in Adipose-Hypothalamic Crosstalk and the Contribution of Aryl Hydrocarbon Receptor to Regulate Energy Homeostasis.

There are fundamental sex differences in the regulation of energy homeostasis. Better understanding of the underlying mechanisms of energy balance that account for this asymmetry will assist in developing sex-specific therapies for sexually dimorphic diseases such as obesity. Multiple organs, including the hypothalamus and adipose tissue, play vital roles in the regulation of energy homeostasis, which are regulated differently in males and females. Various neuronal populations, particularly within the hypothalamus, such as arcuate nucleus (ARC), can sense nutrient content of the body by the help of peripheral hormones such leptin, derived from adipocytes, to regulate energy homeostasis. This review summarizes how adipose tissue crosstalk with homeostatic network control systems in the brain, which includes energy regulatory regions and the hypothalamic–pituitary axis, contribute to energy regulation in a sex-specific manner. Moreover, development of obesity is contingent upon diet and environmental factors. Substances from diet and environmental contaminants can exert insidious effects on energy metabolism, acting peripherally through the aryl hydrocarbon receptor (AhR). Developmental AhR activation can impart permanent alterations of neuronal development that can manifest a number of sex-specific physiological changes, which sometimes become evident only in adulthood. AhR is currently being investigated as a potential target for treating obesity. The consensus is that impaired function of the receptor protects from obesity in mice. AhR also modulates sex steroid receptors, and hence, one of the objectives of this review is to explain why investigating sex differences while examining this receptor is crucial. Overall, this review summarizes sex differences in the regulation of energy homeostasis imparted by the adipose–hypothalamic axis and examines how this axis can be affected by xenobiotics that signal through AhR.

Efficient energy balancing across multiple harmonics of nonlinear normal modes

Predicting the forced responses of nonlinear systems is a topic that attracts extensive studies. The energy balancing method considers the net energy transfer in and out of the system over one period and establishes connections between forced responses and nonlinear normal modes (NNMs). In this paper, we consider the energy balancing across multiple harmonics of NNMs for predicting forced resonances. This technique is constructed by combining the energy balancing mechanism with restrictions (established via excitation scenarios) on external forcing and harmonic phase-shifts; a semi-analytical framework is derived to achieve both accurate/robust results and efficient computations. With known inputs from NNM solutions, the required forcing amplitudes to reach NNMs at resonances, along with their discrepancy, i.e. the harmonic phase-shifts, are computed via a one-step scheme. Several examples are presented for different excitation scenarios to demonstrate the applicability of this method and to show its capability in accurately predicting the existence of an isola where multiple harmonics play a significant part in the response.

Effects of Concentrate Levels in Prepartum Diet on Milk Performance, Energy Balance and Rumen Fermentation of Transition Montbéliarde-Holstein Crossbred Cows.

Simple SummaryThe transition period (3 wks before to 3 wks after calving) is an important period in the lactation cycle of dairy cows. During this period, dairy cows undergo a series of physiological and metabolic changes due to the demands of pregnancy, parturition and postpartum lactation, which can easily lead to a negative energy balance (NEB). Therefore, the energy balance and nutritional regulation mechanism of dairy cows during the transition period are the focus of dairy cow nutrition and physiology research. However, crossbred cows have received less attention to date. Our study showed that feeding a prenatal concentrate mix at a rate of 0.6% of the body weight of Montbéliarde–Holstein crossbred cows has no negative effect on the performance and rumen fermentation of postpartum dairy cows and can satisfy the energy needs of dairy cows in the prepartum period. Furthermore, our data provide a theoretical basis for further revisions to the feeding standard and to alleviate the NEB of Montbéliarde–Holstein crossbred cows in China.This study was conducted to investigate the effect of three rates of prepartum dietary concentrate feeding on the milk performance, energy balance, and rumen fermentation of Montbéliarde–Holstein crossbred cows. Eighteen transition Montbéliarde–Holstein crossbred cows with similar days of gestation (258 ± 12 day) and body weights (622 ± 44 kg) were selected and randomly divided into three groups. In the prepartum period, the addition of concentrates accounted for 0.3% (low concentrate, LC), 0.6% (medium concentrate, MC), and 0.9% (high concentrate, HC) of the cow’s body weight. The forage was corn stover, which was fed to the cows ad libitum with free access to water. Postpartum, all of the cows were fed a common lactation total mixed ration. The experimental period lasted from 21 days prepartum to 28 days postpartum. The energy balance (EB), net energy intake (NEI), and dry matter intake (DMI) of the HC group were greater than those of the other groups (p < 0.05). Likewise, the non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), and total bilirubin (TBIL) in the blood of the LC group had significantly higher concentrations than they did in the other groups (p < 0.05). Moreover, the increase in the level of dietary concentrate had no significant effect on the rumen fermentation parameters (p > 0.05), and the total intestinal digestibility of dry matter (DM), crude protein (CP), and ether extract (EE) in the HC group was significantly higher (p < 0.05) than it was in the other groups during the prepartum period. In conclusion, the administration of the MC diet in the prepartum period had no negative effect on the performance and rumen fermentation of postpartum dairy cows and can satisfy the energy needs of prepartum dairy cows. Therefore, under our experimental conditions, the 0.6% prenatal concentrate feeding amount was the most appropriate for Montbéliarde–Holstein crossbred cows.

A comprehensive framework for early-onset colorectal cancer research.

Sporadic colorectal cancer has traditionally been viewed as a malignancy of older individuals. However, as the global prevalence of the disease diagnosed in younger individuals (<50 years) is expected to increase within the next decade, greater recognition is now being given to early-onset colorectal cancer. The cause of the predicted rise in prevalence is largely unknown and probably multifactorial. In this Series paper, we discuss the potential underlying causes of early-onset colorectal cancer, the role of energy balance, biological and genomic mechanisms (including microbiome aspects), and the treatment of early-onset colorectal cancer. We have specifically considered the psychosocial challenges of being diagnosed with colorectal cancer at younger age and the potential financial toxicity that might ensue. This Series paper brings a comprehensive review based on the existing data in the hopes of optimising the overall outcomes for patients with early-onset colorectal cancer.

Exploring the Ecological Climate Effects Based on Five Land Use Types: A Case Study of the Huang-Huai-Hai River Basin in China

As one of the main driving forces for the change in surface energy balance, land use and cover change affects the ecological climate through different levels of biogeochemical and physical processes. However, many studies on the surface energy balance are conducted from the perspective of biogeochemistry, ignoring biogeochemical processes. By using core methods such as the surface energy balance algorithm and Mann-Kendall trend test, we analyzed the surface energy balance mechanism and ecological climate effects of five land use types in the Huang-Huai-Hai Basin in China. The results showed that: (1) the net radiation and latent heat flux in the five land use types increased significantly, and their highest values were located in cropland areas and urban expansion areas, respectively. (2) The influence of net radiation on surface energy absorption was greater than latent heat flux. This relationship was more obvious in land use types that were greatly influenced by human activities. (3) The net surface energy intake in the Huang-Huai-Hai River Basin showed a decreasing trend and decreased with the increase in human influence intensity, indicating that human activities weakened the positive trend in net surface energy intake and increased the warming effect. This study reveals the difference in energy budgets of different land use types under the influence of human activities. It is helpful for understanding how to formulate sustainable land management strategies, and it also provides a theoretical basis for judging the climate change trends and urban heat island effects in the Huang-Huai-Hai River Basin from a biogeophysical perspective.

Adipocyte function and the development of cardiometabolic disease.

Obesity is a medical disorder caused by multiple mechanisms of dysregulated energy balance. A major consequence of obesity is an increased risk to develop diabetes, diabetic complications and cardiovascular disease. While a better understanding of the molecular mechanisms linking obesity, insulin resistance and cardiovascular disease is needed, translational research of the human pathology is hampered by the available cellular and rodent model systems. Major barriers are the species-specific differences in energy balance, vascular biology and adipose tissue physiology, especially related to white and brown adipocytes, and adipose tissue browning. In rodents, non-shivering thermogenesis is responsible for a large part of energy expenditure, but humans possess much less thermogenic fat, which means temperature is an important variable in translational research. Mouse models with predisposition to dyslipidaemia housed at thermoneutrality and fed a high-fat diet more closely reflect human physiology. Also, adipocytes play a key role in the endocrine regulation of cardiovascular function. Adipocytes secrete a variety of hormones, lipid mediators and other metabolites that directly influence the local microenvironment as well as distant tissues. This is specifically apparent in perivascular depots, where adipocytes modulate vascular function and inflammation. Altogether, these mechanisms highlight the critical role of adipocytes in the development of cardiometabolic disease.

DEVELOPMENT OF WOOD GRINDING. 3. FURTHER TESTING OF GRINDING MODELS

"The study is the continuation of a sequence of works devoted to describing the mechanisms occurring during stone grinding of wood. This part was aimed at further testing of pressurised grinding of spruce wood, which was conducted under controlled laboratory conditions. Testing of the developed theoretical model for power ratio (Pc/Pt) versus energy specific production (Ġw/Pt) produced linears for data representing constant wood moisture content. However, the linears showed almost identical results for fresh woods, and also for drier wood, e.g. wood containing saturated fibres and air-dried wood, although one would expect some differences due to the widely varying constant moisture, from 65% to 15% moisture content. Simplification of the model resulted in (cw + X cm) ΔTp-w ≈ Pt / Ġw, and it led to specific linears, when the members as such were correlated between themselves at several constant wood moisture contents. The results were briefly as follows. Increasing wood feed rate – 0.7, 1.0 and 1.3 mm/s – decreased the specific energy requirement, while increased stone surface speed – 20 and 30 m/s – increased it. The left-hand member or the “X-factor” as named in this context, correlated with the right-hand member or the specific energy requirement and resulted in declining linears. The lower the wood moisture content – 65, 58, 44, 28 and 15% – the smaller was the linear declination, and also the difference due to stone surface speed. The application of an energy balance could be useful in searching for a working wood grinding model. Such a model would enable critical examination of wood grinding conditions. Also, it would help understanding the mechanism of various factors, such as grinding parameters, wood properties and stone burr and sharpness. It seems that there are factors that are not known well enough for further development of grinding. Shower water flow and temperature affect the stone surface temperature as known, but their significance for the energy balance or grinding mechanism are not known. Also, the thin film of pulp slurry between the stone surface and the heat activated wood layer is evidently a significant factor that is connected to the local energy transfer. "

Residual thermic effects of diet induced thermogenesis (RDIT) in aging lean and obese LA/Ntu1//-cp (corpulent) rats

Diet induced thermogenesis has been proposed to account for up to 15% of the caloric content of an ingested meal and to become decreased with aging and in obesity. Genetically obese rodents have been shown to exhibit impairments in the thermic responses to diet and environment, which may partially account for an improved caloric efficiency and to contribute to their increased propensity to become obese. In the present study we sought to determine the thermic responses to diet and environment in aging obese rats when young, middle aged, and aged. Resting oxygen consumption tended to decrease with advancing age and the thermic responses were lower than predicted in obese than in lean rats. This study provides important new insights regarding the thermogenic effects of diet and diet induced thermogenesis and their potential contributions to mechanisms of energy balance across the spectrum of aging in lean and obese LA/Ntul//-cp rats