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Nutritional Strategies (nutritional + strategy)
Selected AbstractsSpecific insulin sensitivity and leptin responses to a nutritional treatment of obesity via a combination of energy restriction and fatty fish intakeJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 6 2008I. Abete Abstract Background, Nutritional strategies to treat obesity often influence neuroendocrine factors related to body weight control. The present study aimed to investigate whether the inclusion of three fatty fish servings per week within a hypocaloric diet may have specific healthy effects on insulin and leptin functions. Methods, Thirty-two subjects (body mass index = 31.6 ± 3.5 kg m,2) aged 36 ± 7 years, were assigned to a control or fish-based energy-restricted diet over an 8-week period. Anthropometry, body composition, lipid profile, leptin and insulin values were measured at the start and at the end of the dietary intervention. Results, Both experimental diets resulted in a similar mean weight loss (control = 5.3 ± 2.6% versus fish-based = 5.5 ± 2.5%; P = 0.783). A significant reduction in insulin resistance, as determined by the homeostatic model assessment index (HOMA-IR = insulin × glucose/22.5), was observed after the fish-based intervention. The change in circulating leptin was higher in the fish-based diet compared to the control group. Sixteen percent of the variability in the change of adjusted-leptin could be explained (P = 0.034) by the HOMA index change and the type of diet. Conclusions, Three servings a week of fatty fish included in an energy-restricted diet appears to be a valid strategy for specifically improving insulin sensitivity and leptin levels in obese subjects, which could involve a better body weight regulation after a nutritional intervention period. [source] Towards effective nutritional management of waste outputs in aquaculture, with particular reference to salmonid aquaculture operationsAQUACULTURE RESEARCH, Issue 5 2010Dominique P Bureau Abstract Long-term sustainability of many fish culture operations may be dependent on their ability to reduce their waste outputs. The release of solid wastes is mainly a function of the digestibility of various dietary components, and the release of dissolved wastes is mainly a function of the metabolism of nutrients by the fish. Consequently, simple principles of nutrition and models have been effectively used to describe, predict and manage the excretion of wastes by fish. Nutritional strategies offer a direct and effective way of managing waste output by aquaculture operations. Very significant reduction in waste outputs per unit of fish produced, notably in terms for solid and phosphorus wastes, have been achieved over the past few decades by commercial fish culture operations. Further reduction in waste outputs could be achieved through fine-tuning of feed formulations, judicious use of feed additives and processing/refining of ingredients. A better understanding of the basis of the effect of various endogenous (biological) and exogenous (dietary, environmental) factors on nutrient utilization by fish could also contribute to the development of strategies for reducing waste outputs. The present paper provides a brief overview of issues and challenges related to potential environmental impacts of wastes, and of recent progresses relative to nutritional strategies aimed at better management of the release of wastes by aquaculture operations. [source] Linear models to predict the digestible lipid content of fish dietsAQUACULTURE NUTRITION, Issue 5 2009J. SALES Abstract Values for the digestible contents of nutrients in diets and feed ingredients are of utmost importance in nutritional strategies for fish. Prediction from dietary composition would eliminate lengthy, tedious and demanding digestibility experiments with fish. Apparent digestible lipid (DL) content [range 7.6,353.4 g kg,1 dry matter (DM)] in compound diets can be predicted with high accuracy (n = 610; studies =127; fish species = 34; R2 = 0.9515; RMSE = 16.9504) from dietary crude lipid (CL) content (range 12.0,388.7 g kg,1 DM) by the linear regression equation DL =,2.7303 + 0.9123 CL. Validation of this equation against 65 values from 15 independent studies presented R2 and mean prediction error (MPE) values of 0.9947 and 0.0671, respectively. The corresponding equation for 37 individual feed ingredients evaluated in 24 studies with 18 fish species (n = 180) was found to be DL = ,1.5824 + 0.8654 CL (R2 = 0.9717; RMSE = 8.3765). However, validation of the latter is currently hampered by a lack of independent values. [source] Towards effective nutritional management of waste outputs in aquaculture, with particular reference to salmonid aquaculture operationsAQUACULTURE RESEARCH, Issue 5 2010Dominique P Bureau Abstract Long-term sustainability of many fish culture operations may be dependent on their ability to reduce their waste outputs. The release of solid wastes is mainly a function of the digestibility of various dietary components, and the release of dissolved wastes is mainly a function of the metabolism of nutrients by the fish. Consequently, simple principles of nutrition and models have been effectively used to describe, predict and manage the excretion of wastes by fish. Nutritional strategies offer a direct and effective way of managing waste output by aquaculture operations. Very significant reduction in waste outputs per unit of fish produced, notably in terms for solid and phosphorus wastes, have been achieved over the past few decades by commercial fish culture operations. Further reduction in waste outputs could be achieved through fine-tuning of feed formulations, judicious use of feed additives and processing/refining of ingredients. A better understanding of the basis of the effect of various endogenous (biological) and exogenous (dietary, environmental) factors on nutrient utilization by fish could also contribute to the development of strategies for reducing waste outputs. The present paper provides a brief overview of issues and challenges related to potential environmental impacts of wastes, and of recent progresses relative to nutritional strategies aimed at better management of the release of wastes by aquaculture operations. [source] Enhancing the natural defences and barrier protection of aquaculture speciesAQUACULTURE RESEARCH, Issue 3 2010John W Sweetman Abstract The promotion of nutritional strategies that optimize natural defence mechanisms in fish is of critical importance in producing robust juveniles and adult fish. These animals are more capable of minimizing the impact of opportunistic pathogen attack, thus improving liveability and performance characteristics. The importance of the piscine gastrointestinal tract as a major endocrine and osmoregulatory organ is well reported as is its function as a defensive barrier to pathogen attack. Investigations using the inclusion of a specific structural form of mannan oligosaccharide have been shown to improve the performance parameters, immune status, and gut morphology and improve an important aspect of barrier protection through the enhancement of mucal production in a number of aquaculture species. The selenium status of an animal is pivotal in determining the success of the innate and adaptive immune response of the animal, and the use of an organic selenium source, in the form of a selenoyeast, has been shown to improve enzyme function and tissue uptake. The antioxidant role of many of the selenoptroteins and the role of selenium in the glutathione peroxidase enzyme pathways involved in the control of oxidative stress is critical if oxidative damage and cell membrane lipid peroxidation are to be prevented. The use of these compounds as feed additives has important implications for health management in commercial aquaculture facilities. Further research is needed to evaluate the benefits offered by a range of commercial products. [source] Effect of AOB, a fermented-grain food supplement, on oxidative stress in type 2 diabetic ratsBIOFACTORS, Issue 2 2007Yukiko Minamiyama Abstract Reactive oxygen species (ROS) play an important role in the pathogenesis of diabetic complications. Antioxidant Biofactor (AOB) is a mixture of commercially available fermented grain foods and has strong antioxidant activity. This study investigated the effect of AOB supplementation of standard rat food on markers of oxidative stress and inflammation in Otsuka Long-Evans Tokushima Fatty (OLETF) rats with type 2 diabetes. Blood glucose, hemoglobin A1c, plasma free fatty acid, triacylglycerol and plasminogen activator inhibitor-1 (PAI-1) were significantly higher in OLETF rats than in non-diabetic control Long-Evans Tokushima Otsuka (LETO) rats at 29 weeks. AOB (6.5% of diet) was given to rats during 29,33 weeks of diabetic phase in OLETF rats. OLETF rats with AOB supplementation showed decreased blood glucose, hemoglobin A1c, triacylgycerol, low density lipoprotein, cholesterol and PAI-1. Mitochondrial ROS production was significantly increased in heart, aorta, liver and renal artery of OLETF rats. Uncoupling protein 2 (UCP2) is known to regulate ROS production. We found aortic UCP2 protein expression increased in OLETF rats, and AOB returned UCP2 expression to normal. Aortic endothelial NO synthase (eNOS) was also increased in OLETF rats more than in LETO rats at 33 weeks. In contrast, phosphorylated vasodilator-stimulated phosphoprotein, an index of the NO-cGMP pathway, was significantly diminished. AOB increased eNOS proteins in LETO and OLETF rats. In conclusion, AOB significantly improved the NO-cGMP pathway via normalizing ROS generation in OLETF rats. The data suggest that dietary supplementation with AOB contributes to nutritional strategies for the prevention and treatment of type 2 diabetes mellitus. [source] Multiple origins of symbioses between ascomycetes and bryophytes suggested by a five-gene phylogenyCLADISTICS, Issue 3 2010Soili Stenroos Numerous species of microscopic fungi inhabit mosses and hepatics. They are severely overlooked and their identity and nutritional strategies are mostly unknown. Most of these bryosymbiotic fungi belong to the Ascomycota. Their fruit-bodies are extremely small, often reduced and simply structured, which is why they cannot be reliably identified and classified by their morphological and anatomical characters. A phylogenetic hypothesis of bryosymbiotic ascomycetes is presented. New sequences of 78 samples, including 61 bryosymbionts, were produced, the total amount of terminals being 206. Of these, 202 are Ascomycetes. Sequences from the following five gene loci were used: rDNA SSU, rDNA LSU, RPB2, mitochondrial rDNA SSU, and rDNA 5.8S. The program TNT was used for tree search and support value estimation. We show that bryosymbiotic fungi occur in numerous lineages, one of which represents a newly discovered lineage among the Ascomycota and exhibits a tripartite association with cyanobacteria and sphagna. A new genus Trizodia is proposed for this basal clade. Our results demonstrate that even highly specialized life strategies can be adopted multiple times during evolution, and that in many cases bryosymbionts appear to have evolved from saprobic ancestors. ,© The Willi Hennig Society 2009. [source] Characterizing the nutritional strategy of incubating king eiders Somateria spectabilis in northern AlaskaJOURNAL OF AVIAN BIOLOGY, Issue 6 2008Rebecca L. Bentzen We measured plasma concentrations of variables associated with lipid metabolism (free fatty acids, glycerol, triglyceride, and ,-hydroxybutyrate), protein metabolism (uric acid), and baseline corticosterone to characterize the nutritional state of incubating king eiders Somateria spectabilis and relate this to incubation constancy at two sites, Kuparuk and Teshekpuk, in northern Alaska. King eiders at both sites appeared to employ a partial-income incubation strategy, relying on both endogenous and exogenous energy resources. Females maintained high invariant levels of free fatty acids, ,-hydroxybutyrate, and glycerol throughout incubation, indicating that fat reserves were a major energy source, and not completely depleted during incubation. Similarly, uric acid did not increase, suggesting effective protein sparing or protein ingestion and adequate lipid reserves throughout incubation. Baseline corticosterone and triglyceride levels increased during incubation, indicative of an increase in foraging during late stages of incubation. Incubating females at Kuparuk had higher triglyceride concentrations but also had higher ,-hydroxybutyrate concentrations than females at Teshekpuk. This dichotomy may reflect a short-term signal of feeding overlaying the longer-term signal of reliance on endogenous lipid reserves due to higher food intake yet higher metabolic costs at Kuparuk because of its colder environment. Incubation constancy was not correlated with plasma concentrations of lipid or protein metabolites. 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