Influence of Dietary Oil Content and Conjugated Linoleic Acid (CLA) on Lipid Metabolism Enzyme Activities and Gene Expression in Tissues of Atlantic Salmon (Salmo salar L.)

The overall objective is to test the hypothesis that conjugated linoleic acid (CLA) has beneficial effects in Atlantic salmon through affecting lipid and fatty acid metabolism. The specific aims of the present study were to determine the effects of CLA on some key pathways of fatty acid metabolism including fatty acid oxidation and highly unsaturated fatty acid (HUFA) synthesis. Salmon smolts were fed diets containing two levels of fish oil (low, ~18% and high, ~34%) containing three levels of CLA (a 1:1 mixture of 9-cis,trans-11 and trans-10,cis-12 at 0, 1 and 2% of diet) for 3 months. The effects of dietary CLA on HUFA synthesis and β-oxidation were measured and the expression of key genes in the fatty acid oxidation and HUFA synthesis pathways, and potentially important transcription factors, peroxisome proliferators activated receptors (PPARs), determined in selected tissues. Liver HUFA synthesis and desaturase gene expression was increased by dietary CLA and decreased by high dietary oil content. Carnitine palmitoyltransferase-I (CPT-I) activity and gene expression were generally increased by CLA in muscle tissues although dietary oil content had relatively little effect. In general CPT-I activity or gene expression was not correlated with β-oxidation. Dietary CLA tended to increase PPARα and β gene expression in both liver and muscle tissues, and PPARγ in liver. In summary, gene expression and activity of the fatty acid pathways were altered in response to dietary CLA and/or oil content, with data suggesting that PPARs are also regulated in response to CLA. Correlations were observed between dietary CLA, liver HUFA synthesis and desaturase gene expression, and liver PPARα expression, and also between dietary CLA, CPT-I expression and activity, and PPARα expression in muscle tissues. In conclusion, this study suggests that dietary CLA has effects on fatty acid metabolism in Atlantic salmon and on PPAR transcription factors. However, further work is required to assess the potential of CLA as a dietary supplement, and the role of PPARs in the regulation of lipid metabolism in fish

What to think of canine obesity? Emerging challenges to our understanding of human-animal health relationships.

The coincident and increasing occurrence of weight-related health problems in humans and canines in Western societies poses a challenge to our understanding of human–animal health relationships. More specifically, the epistemological and normative impetus provided by current approaches to shared health risks and chronic diseases in cohabiting human and animal populations does not account for causal continuities in the way that people and their pets live together. An examination of differences in medical responses to these conditions in human and pet dogs points to the existence of a distinct conceptual and ethical sphere for companion animal veterinary medicine. The disengagement of veterinary medicine for companion animals from human medicine has implications for our understanding what is required for health and disease prevention at the level of populations. This disengagement of companion animal veterinarians from family and preventive medicine, in particular, constrains professional roles, planning processes and, thereby, the potential for better-integrated responses to shared burdens of chronic conditions that increasingly affect the health and welfare of people and companion animals. Keywords: Human–Animal Relationships, Medical Epistemology, Companion Animal Welfare, Veterinary Ethics, Public Health Ethics, One HealthCanadian Institutes of Health Research, Open Operating Gran

Size of the cooperative rearranging regions vs. fragility in complex glassy systems: Influence of the structure and the molecular interactions

International audienceBy using Donth's model, the size of the Cooperative Rearranging Regions (CRR) at the glass transition was determined from TM-DSC measurements on two glassy biopolymers with different molecular structures (amylose and amylopectin) as well as on starch, which is the mixture of amylose and amylopectin as it is obtained during its biosynthesis. For these materials, the Delta C-p values at T-g and the values of the fragility index (m) were determined by conventional DSC. The fragility concept was then analyzed by taking into account the existence of two contributions: m(isoV) (the so-called isochoric fragility, which is a pure thermal contribution) and m(Delta v) (which incorporates the effects due to volume and density fluctuations). Whenever the molecular structure of a glass-forming liquid involves non-linear sequences of rigid and sterically hindered repeating units with high densities of hydrogen bonds, the fragility is found to be governed only by the temperature; the contribution of the volume (density and pressure contribution) has a quasi-nil effect. (c) 2013 Elsevier B.V. All rights reserved

Is the configurational entropic model able to predict the final equilibrium state reached by Se glasses after very long ageing durations?

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