The effect of 5 days of aspartate and asparagine supplementation on glucose transport activity in rat muscle

The consumption of protein supplements containing amino acids is increasing around the world Aspartate (Asp) and asparagine (Asn) are amino acids metabolized by skeletal muscle. This metabolism involves biochemical pathways that are involved in increasing Krebs cycle activity via anaplerotic reactions. resulting in higher glutamine concentrations. A connection between amino acid supplementation, glycogen concentration, and glucose uptake has been previously demonstrated. The purpose of this study was to evaluate the effect of asp and Asn Supplementation on glucose uptake in rats using three different glycogen concentrations The results indicate that Asp and Asn supplementation in rats with high glycogen concentrations (fed state) further increased the glycogen concentration in the muscle, and decreased in vitro 2-deoxyglucose (a glucose analog.) uptake by the muscle at maximal insulin concentrations When animals had a medium glycogen concentration (consumed lard for 3 days). glucose uptake was higher in the supplemented group at sub-maximal insulin concentrations. We conclude that supplementation of Asp and Asn reduced glucose transport in rat muscle only at higher levels of glycogen. The ingestion of lard for 3 days changed the responsiveness and sensitivity to insulin, and that group had higher levels of insulin sensivity with Asp and Asn supplementation. Copyright (C) 2009 John Wiley & Sons, Ltd.

Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial

Creatine (CR) supplementation is commonly used by athletes. However, its effects on renal function remain controversial. The aim of this study was to evaluate the effects of creatine supplementation on renal function in healthy sedentary males (18-35 years old) submitted to exercise training. A randomized, double-blind, placebo-controlled trial was performed. Subjects (n = 18) were randomly allocated to receive treatment with either creatine (CR) (similar to 10 g day(-1) over 3 months) or placebo (PL) (dextrose). All subjects undertook moderate intensity aerobic training, in three 40-min sessions per week, during 3 months. Serum creatinine, serum and urinary sodium and potassium were determined at baseline and at the end of the study. Cystatin C was assessed prior to training (PRE), after 4 (POST 4) and 12 weeks (POST 12). Cystatin C levels (mg L-1) (PRE CR: 0.82 +/- 0.09; PL: 0.88 +/- 0.07 vs. POST 12 CR: 0.71 +/- 0.06; PL: 0.75 +/- 0.09, P = 0.0001) were decreased over time, suggesting an increase in glomerular filtration rate. Serum creatinine decreased with training in PL but was unchanged with training in CR. No significant differences were observed within or between groups in other parameters investigated. The decrease in cystatin C indicates that high-dose creatine supplementation over 3 months does not provoke any renal dysfunction in healthy males undergoing aerobic training. In addition, the results suggest that moderate aerobic training per se may improve renal function.

Effects of creatine supplementation on glucose tolerance and insulin sensitivity in sedentary healthy males undergoing aerobic training

Recent findings have indicated that creatine supplementation may affect glucose metabolism. This study aimed to examine the effects of creatine supplementation, combined with aerobic training, on glucose tolerance in sedentary healthy male. Subjects (n = 22) were randomly divided in two groups and were allocated to receive treatment with either creatine (CT) (similar to 10g .day over three months) or placebo (PT) (dextrose). Administration of treatments was double blind. Both groups underwent moderate aerobic training. An oral glucose tolerance test (OGTT) was performed and both fasting plasma insulin and the homeostasis model assessment (HOMA) index were assessed at the start, and after four, eight and twelve weeks. CT demonstrated significant decrease in OGTT area under the curve compared to PT (P = 0.034). There were no differences between groups or over time in fasting insulin or HOMA. The results suggest that creatine supplementation, combined with aerobic training, can improve glucose tolerance but does not affect insulin sensitivity, and may warrant further investigation with diabetic subjects.

Branched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion

Aim. It has been demonstrated that branched-chain amino acids (BCAA) transaminase activation occurs simultaneously with exercise-induced muscle glycogen reduction, suggesting that BCAA supplementation might play an energetic role in this condition. This study aimed to test whether BCAA supplementation enhances exercise capacity and lipid oxidation in glycogen-depleted subjects. Methods. Using a double-blind cross-over design, volunteers (N.=7) were randomly assigned to either the BCAA (300 mg . kg . day (-1)) or the placebo (maltodextrine) for 3 days. On the second day, subjects were submitted to an exercise-induced glycogen depletion protocol. They then performed an exhaustive exercise test on the third day, after which time to exhaustion, respiratory exchange ratio (RER), plasma glucose, free fatty acids (HA), blood ketones and lactate were determined. BCAA supplementation promoted a greater resistance to fatigue when compared to the placebo (+17.2%). Moreover, subjects supplemented with BCAA showed reduced RER and higher plasma glucose levels during the exhaustive exercise test. Results. No significant differences appeared in FFA, blood ketones and lactate concentrations. Conclusion. In conclusion, BCAA supplementation increases resistance to fatigue and enhances lipid oxidation during exercise in glycogen-depleted subjects.

Effects of medium supplementation and pH control on lactic acid production from brewer`s spent grain

A cellulose pulp obtained by chemical pre-treatment of brewer`s spent grain was saccharified by a commercial cellulase preparation and the produced hydrolysate (50 g/l glucose) was fermented to lactic acid by Lactobacillus delbrueckii. The effects of pH control and nutrient supplementation of the hydrolysate on fermentation performance were investigated. Addition of 5g/l yeast extract enhanced the lactic acid volumetric productivity that attained 0.53 g/l h, value 18% higher than that obtained from non-supplemented hydrolysate. Addition of the MRS broth medium components (except the carbon source) was still better, providing a productivity of 0.79 g/l h. In all the cases, the lactic acid yield factor was of 0.7 g/g glucose consumed, but the fermentations stopped after 24 h due to the pH drop from 6.0 to 4.2, resulting in large amounts of residual glucose (38-41 g/l). Fermentation runs pH-controlled at 6.0 gave better results than those where the initial pH was not further controlled. The best result, 35.54 g/l lactic acid (0.99 g/g glucose consumed) was obtained during the pH-controlled fermentation of hydrolysate medium supplemented with MRS components. The volumetric productivity at the end of this fermentation was 0.59 g/l h, with a maximum of 0.82 g/l h during the first 12 h. (c) 2008 Elsevier B.V. All rights reserved.

Establishment of the optimum initial xylose concentration and nutritional supplementation of brewer`s spent grain hydrolysate for xylitol production by Candida guilliermondii

The effects of initial xylose concentration and nutritional supplementation of brewer`s spent grain hydrolysate on xylitol production by Candida guilliermondii were evaluated using experimental design methodology. The hydrolysate containing 55, 75 or 95 g/l xylose, supplemented or not with nutrients (calcium chloride, ammonium sulfate and rice bran extract), was used as fermentation medium. The increase in xylitol yield and productivity was related to the increase of initial xylose concentration, but up to a certain limit. above of which the yeast performance was not improved. The hydrolysate supplementation with nutrients did not interfere with xylose-to-xylitol conversion. By using the statistic tool the best conditions for maximum xylitol production were found. which consisted in using the non-supplemented hydrolysate containing 70 g/l initial xylose concentration. Under these conditions, a xylitol yield of 0.78 g/g and productivity of 0.58 g/(l h) were achieved. (C) 2008 Elsevier Ltd. All rights reserved.

Anaerobic sequencing batch biofilm reactor applied to automobile industry wastewater treatment: Volumetric loading rate and feed strategy effects

This paper presents a technological viability study of wastewater treatment in an automobile industry by an anaerobic sequencing batch biofilm reactor containing immobilized biomass (AnSBBR) with a draft tube. The reactor was operated in 8-h cycles, with agitation of 400 rpm, at 30 degrees C and treating 2.0 L wastewater per cycle. Initially the efficiency and stability of the reactor were studied when supplied with nutrients and alkalinity. Removal efficiency of 88% was obtained at volumetric loading rate (VLR) of 3.09 mg COD/L day. When VLR was increased to 6.19 mg COD/L day the system presented stable operation with reduction in efficiency of 71%. In a second stage the AnSBBR was operated treating wastewater in natura, i.e., without nutrients supplementation, only with alkalinity, thereby changing feed strategy. The first strategy consisted in feeding 2.0 L batch wise (10 min), the second in feeding 1.0 L of influent batch wise (10 min) and an additional 1.0 L fed-batch wise (4 h), both dewatering 2.0 L of the effluent in 10 min. The third one maintained 1.0 L of treated effluent in the reactor, without discharging, and 1.0 L of influent was fed fed-batch wise (4 h) with dewatering 1.0 L of the effluent in 10 min. For all implemented strategies (VLR of 1.40, 2.57 and 2.61 mg COD/L day) the system presented stability and removal efficiency of approximately 80%. These results show that the AnSBBR presents operational flexibility, as the influent can be fed according to industry availability. In industrial processes this is a considerable advantage, as the influent may be prone to variations. Moreover, for all the investigated conditions the kinetic parameters were obtained from fitting a first-order model to the profiles of organic matter, total volatile acids and methane concentrations. Analysis of the kinetic parameters showed that the best strategy is feeding 1.0 L of influent batchwise (10 min) and 1.0 L fed-batch wise (4 h) in 8-h cycle. (c) 2007 Elsevier B.V. All rights reserved.

Three-phase harmonic distortion state estimation algorithm based on evolutionary strategies

This paper presents a new methodology to estimate unbalanced harmonic distortions in a power system, based on measurements of a limited number of given sites. The algorithm utilizes evolutionary strategies (ES), a development branch of evolutionary algorithms. The problem solving algorithm herein proposed makes use of data from various power quality meters, which can either be synchronized by high technology GPS devices or by using information from a fundamental frequency load flow, what makes the overall power quality monitoring system much less costly. The ES based harmonic estimation model is applied to a 14 bus network to compare its performance to a conventional Monte Carlo approach. It is also applied to a 50 bus subtransmission network in order to compare the three-phase and single-phase approaches as well as the robustness of the proposed method. (C) 2010 Elsevier B.V. All rights reserved.

Swarm Intelligence applied in synthesis of hunting strategies in a three-dimensional environment

Systems of distributed artificial intelligence can be powerful tools in a wide variety of practical applications. Its most surprising characteristic, the emergent behavior, is also the most answerable for the difficulty in. projecting these systems. This work proposes a tool capable to beget individual strategies for the elements of a multi-agent system and thereof providing to the group means on obtaining wanted results, working in a coordinated and cooperative manner as well. As an application example, a problem was taken as a basis where a predators` group must catch a prey in a three-dimensional continuous ambient. A synthesis of system strategies was implemented of which internal mechanism involves the integration between simulators by Particle Swarm Optimization algorithm (PSO), a Swarm Intelligence technique. The system had been tested in several simulation settings and it was capable to synthesize automatically successful hunting strategies, substantiating that the developed tool can provide, as long as it works with well-elaborated patterns, satisfactory solutions for problems of complex nature, of difficult resolution starting from analytical approaches. (c) 2007 Elsevier Ltd. All rights reserved.

Understanding the strategies of late-movers in International Manufacturing

This paper analyzes the internationalization of new multinationals from emerging countries. It also focuses on Production`s role in firm internationalization, a subject seldom addressed because the discipline of International Manufacturing is still embryonic, while International Business tends to overlook production. The authors integrate International Business and International Manufacturing concepts and frameworks in order to analyze new multinationals from emerging countries, using the empirical evidence of a survey plus case studies of Brazilian multinationals for understanding late-movers` strategies and competences, with emphasis on production. (C) 2009 Elsevier B.V. All rights reserved.

Vibration-enhanced posture stabilization achieved by tactile supplementation: May blind individuals get extra benefits?

Diminished balance ability poses a serious health risk due to the increased likelihood of falling, and impaired postural stability is significantly associated with blindness and poor vision. Noise stimulation (by improving the detection of sub-threshold somatosensory information) and tactile supplementation (i.e. additional haptic information provided by an external contact surface) have been shown to improve the performance of the postural control system. Moreover, vibratory noise added to the source of tactile supplementation (e.g. applied to a surface that the fingertip touches) has been shown to enhance balance stability more effectively than tactile supplementation alone. In view of the above findings, in addition to the well established consensus that blind subjects show superior abilities in the use of tactile information, we hypothesized that blind subjects may take extra benefits from the vibratory noise added to the tactile supplementation and hence show greater improvements in postural stability than those observed for sighted subjects. If confirmed, this hypothesis may lay the foundation for the development of noise-based assistive devices (e.g. canes, walking sticks) for improving somatosensation and hence prevent falls in blind individuals. (C) 2011 Elsevier Ltd. All rights reserved.

Using indicators of deforestation and land-use dynamics to support conservation strategies: A case study of central Rondonia, Brazil

In Rondonia State, Brazil, settlement processes have cleared 68,000 km 2 of tropical forests since the 1970s. The intensity of deforestation has differed by region depending on driving factors like roads and economic activities. Different histories of land-use activities and rates of change have resulted in mosaics of forest patches embedded in an agricultural matrix. Yet, most assessments of deforestation and its effects on vegetation, soil and water typically focus on landscape patterns of current conditions, yet historical deforestation dynamics can influence current conditions strongly. Here, we develop and describe the use of four land-use dynamic indicators to capture historical land-use changes of catchments and to measure the rate of deforestation (annual deforestation rate), forest regeneration level (secondary forest mean proportion), time since disturbance (mean time since deforestation) and deforestation profile (deforestation profile curvature). We used the proposed indices to analyze a watershed located in central Rondonia. Landsat TM and ETM+ images were used to produce historical land-use maps of the last 18 years, each even year from 1984 to 2002 for 20 catchments. We found that the land-use dynamics indicators are able to distinguish catchments with different land-use change profiles. Four categories of historical land-use were identified: old and dominant pasture cover on small properties, recent deforestation and dominance of secondary growth, old extensive pastures and large forest remnants and, recent deforestation, pasture and large forest remnants. Knowing historical deforestation processes is important to develop appropriate conservation strategies and define priorities and actions for conserving forests currently under deforestation. (C) 2009 Elsevier B.V. All rights reserved.

Effects of dietary supplementation of rumen-protected conjugated linoleic acid to grazing cows in early lactation

Conjugated linoleic acids (CLA) are potent anticarcinogens in animal and in vitro models as well as inhibitors of fatty acid synthesis in mammary gland, liver, and adipose tissue. Our objective was to evaluate long-term CLA supplementation of lactating dairy cows in tropical pasture on milk production and composition and residual effects posttreatment. Thirty crossbred cows grazing stargrass (Cynodon nlemfuensis Vanderyst var. nlemfuensis) were blocked by parity and received 150 g/d of a dietary fat supplement of either Ca-salts of palm oil fatty acids (control) or a mixture of Ca-salts of CLA (CLA treatment). Supplements of fatty acids were mixed with 4 kg/d of concentrate. Grazing plus supplements were estimated to provide 115% of the estimated metabolizable protein requirements from 28 to 84 d in milk (treatment period). The CLA supplement provided 15 g/d of cis-9, trans-11 and 22 g of cis-10, trans-12. Residual effects were evaluated from 85 to 112 d in milk (residual period) when cows were fed an 18% crude protein concentrate without added fat. The CLA treatment increased milk production but reduced milk fat concentration from 2.90 to 2.14% and fat production from 437 to 348 g/d. Milk protein concentration increased by 11.5% (2.79 to 3.11%) and production by 19% (422 to 504 g/d) in the cows fed CLA. The CLA treatment decreased milk energy concentration and increased milk volume, resulting in unchanged energy output. Milk production and protein concentration and production were also greater during the residual period for the CLA-treated cows. The CLA treatment reduced production of fatty acids (FA) of all chain lengths, but the larger effect was on short-chain FA, causing a shift toward a greater content of longer chain FA. The CLA treatment increased total milk CLA content by 30% and content of the trans-10, cis-12 CLA isomer by 88%. The CLA treatment tended to decrease the number of days open, suggesting a possible effect on reproduction. Under tropical grazing conditions, in a nutritionally challenging environment, CLA-treated cows decreased milk fat content and secreted the same amount of milk energy by increasing milk volume and milk protein production.

Effect of Brazil nut supplementation on the blood levels of selenium and glutathione peroxidase in hemodialysis patients

Objective: In patients who have undergone hemodialysis, large amounts of reactive oxygen species (ROS) are produced and, at higher concentrations, ROS are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an anti-atherogenic influence by reducing oxidative stress. The richest known food source of selenium is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. We evaluated the effect of Brazil nut supplementation on blood levels of Se and glutathione peroxidase (GSH-Px) activity in patients on hemodialysis. Methods: A total of 81 patients on hemodialysis (52.0 +/- 15.2 y old, average time on dialysis 82.3 +/- 91.4 mo, body mass index 24.9 +/- 4.4 kg/m(2)) from the RenalCor and RenalVida Clinics in Rio de Janeiro, Brazil, were studied. All patients received one nut (around 5 g, averaging 58.1 mu g Se/g) a day for 3 mo. The Se concentrations in the nuts and in plasma and erythrocytes were determined by atomic absorption spectrophotometry with hydride generation (Hitachi, Z-500). GSH-Px levels were measured using Randox commercial kits. Results: Plasma Se (18.8 +/- 17.4 mu g/L) and erythrocyte (72.4 +/- 37.9 mg/L) levels were below the normal, range before nut supplementation. After supplementation, the plasma level increased to 104.0 +/- 65.0 mu g/L and erythrocytes to 244.1 +/- 119.5 mg/L (P<0.0001). The activity of GSH-Px also increased after supplementation, from 46.6 +/- 14.9 to 55.9 +/- 23.6 U/g of hemoglobin (P<0.0001). Before supplementation, 11% of patients had GSH-Px activity below the normal range (27.5-73.6 U/g of hemoglobin). After supplementation, all patients showed GSH-Px activity within the normal range. Conclusion: The data revealed that the investigated patients presented Se deficiency and that the consumption of only one Brazil nut a day (5 g) during 3 mo was effective to increase the Se concentration and GSH-Px activity in these patients, thus improving their antioxidant status. (C) 2010 Elsevier Inc. All rights reserved.

Effects of oral supplementation with glutamine and alanyl-glutamine on glutamine, glutamate, and glutathione status in trained rats and subjected to long-duration exercise

Objective: We investigated the effect of supplementation with the dipeptide L-alanyl-L-glutamine (DIP) and a solution containing L-glutamine and L-alanine, both in the free form, on the plasma and tissue concentrations of glutamine, glutamate, and glutathione (GSH) in rats subjected to long-duration exercise. Methods: Rats were subjected to sessions of swim training. Twenty-one days before sacrifice, the animals were supplemented with DIP (1.5 g/kg, n = 6), a solution of free L-glutamine (1 g/kg) and free L-alanine (0.61 g/kg; GLN + ALA, n = 6), or water (CON, n = 6). Animals were sacrificed before (TR, n = 6) or after (LD, n = 6) long-duration exercise. Plasma concentrations of glutamine, glutamate, glucose, and ammonia and liver and muscle concentrations of glutamine, glutamate, and reduced and oxidized (GSSG) GSH were measured. Results: Higher concentrations of plasma glutamine were found in the DIP-TR and GLN + ALA-TR groups. The CON-LD group showed hyperammonemia, whereas the DIP-LD and GLN + ALA-LD groups exhibited lower concentrations of ammonia. Higher concentrations of glutamine, glutamate, and GSH/GSSG in the soleus muscle and GSH and GSH/GSSG in the liver were observed in the DIP-TR and GLN + ALA-TR groups. The DIP-LD and GLN + ALA-LD groups exhibited higher concentrations of GSH and GSH/GSSG in the soleus muscle and liver compared with the CON-LD group. Conclusion: Chronic oral administration of DIP and free GLN + ALA before long-duration exercise represents an effective source of glutamine and glutamate, which may increase muscle and liver stores of GSH and improve the redox state of the cell. (C) 2009 Published by Elsevier Inc.