12,893 research outputs found

    The rabbit in atherosclerosis research

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    The rabbit was the first animal model in atherosclerosis research and it has been the most popular species during the last nine decades despite some critique concerning the nature ofthe experimental atherosclerosis The rabbit fulfils a number ofpractical and biological criteria for being an ideal animal model tor human atherosclerosis. The shortcomings of the Classical rabbit model, the Cholesterol-fed rabbit, concerning the morphology of the lesions have been overcome. and new  genetic variants which offer expanded possibilities of exploring the relationship between lipid metabolism and development of atherosclerosis have been developed. At present the mostly used rabbit models are: the eholesterol-lā€˜ed rabbit. the Watanabe heritable hyperlipidemic rabbit, and St. Thomasā€™ Hospital rabbit Different study designs can be applied to the eholesterol-fed rabbit. Atherosclerosis in rabbit models can be evaluated by macroscopic, biochemical and microseopie methods

    Biotransformation of caffeoyl quinic acids from green coffee extracts by Lactobacillus johnsonii NCC 533

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    Acknowledgements The authors are grateful to Nicole Page-Zoerkler and Olivier Mauroux for their technical assistant. We thank David Pridmore and Kimo Makkinen for critical reading of this manuscript.Peer reviewedPublisher PD

    Extravascular lipid deposition and morphology of atherosclerosis in heterozygous WHHL rabbits fed vegetable (n-6) and marine (11-3) oils

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    The aim of this experiment was to test the cholesterol-fed heterozugous WHHL rabbit as a model for investigation of atherogenicity of different fats. Twentytwo rabbits of both sexes, 8ā€”9.5 months old were randomized in 3 groups, and fed 100 g diet daily: cholesterol enriched standard diet (group I, n=8), cholesterol enriched diet with added vegetable (group II, n=7). or marine (group III, n=7) oils during 14 weeks. The vegetable oil (n-6 = 33 %, nā€”3 less than 1 %) and a marine oil(n-6 = 18 %, n-3 = 17 %) were adjusted to contain equal amounts of saturated and monounsaturated fatty acids. One percent cholesterol in the diet caused a pronounced hypercholesterolemia which was significantly enhanced by addition of oils.The increase in total cholesterol was especially reflected in the increase in the VLDL concentration. The blood cholesterol and triglyceride levels were comparable between the two of fed groups apart from a transitory lowering in the marine oilfed rabbits. The atherosclerotie lesions caused by 1 % cholesterol in the diet were fibrous plaques and plaques with foam cells. The added oils aggravated the atherosclerosis caused by cholesterol. Based on morphological appearance of the aorticand coronary atherosclerosis the marine oil was more atherogcnic than the vegetable oil. In pulmonary arteries, however, the less severe atherosclerotic changes were found in the marine oil group. In this group no lipid infiltrations were seen in the myocardium but very severe infiltrations were seen in the liver. In the vegetable oil group these infiltrations were severe in the myocardium and less pronounced in the liver. The massive hypereholesterolemia and extravascular lipid deposition in different parenchymatous organs suggest that lower doses of dietary cholesterol should be used when the cholesterol-fed heterozygous WHHL rabbit is chosen to study the ellect ot'van'ous fats on blood lipids and developmentof atherosclerosis

    The Exoplanet Census: A General Method, Applied to Kepler

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    We develop a general method to fit the planetary distribution function (PLDF) to exoplanet survey data. This maximum likelihood method accommodates more than one planet per star and any number of planet or target star properties. Application to \Kepler data relies on estimates of the efficiency of discovering transits around Solar type stars by Howard et al. (2011). These estimates are shown to agree with theoretical predictions for an ideal transit survey. Using announced \Kepler planet candidates, we fit the PLDF as a joint powerlaw in planet radius, down to 0.5 R_Eart, and orbital period, up to 50 days. The estimated number of planets per star in this sample is ~ 0.7 --- 1.4, where the broad range covers systematic uncertainties in the detection efficiency. To analyze trends in the PLDF we consider four planet samples, divided between shorter and longer periods at 7 days and between large and small radii at 3 R_Earth. At longer periods, the size distribution of the small planets, with index \alpha = -1.2 \pm 0.2 steepens to \alpha = -2.0 \pm 0.2 for the larger planet sample. For shorter periods, the opposite is seen: smaller planets follow a steep powerlaw, \alpha = -1.9 \pm 0.2 that is much shallower, \alpha = -0.7 \pm 0.2 at large radii. The observed deficit of intermediate-sized planets at the shortest periods may arise from the evaporation and sublimation of Neptune and Saturn-like planets. If the trend and explanation hold, it would be spectacular observational confirmation of the core accretion and migration hypotheses, and allow refinement of these theories.Comment: Submitted to Ap

    How European cardiologists perceive the role of calcium antagonists in follow-up after myocardial infarction

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    About one hundred European cardiologists discussed the role of calcium antagonists in the follow-up management of myocardial infarction, Ī²-blockers are the treatment of choice. Where these are contra-indicated or otherwise unsuitable, many clinicians would use a non-dihydropyridine calcium antagonist alone or in combination with an ACE inhibitor. There is broad agreement that calcium antagonists should not be used in patients with concomitant left ventricular failure. Cholesterol estimation in post-infarction patients is essentia

    The Photoeccentric Effect and Proto-Hot Jupiters I. Measuring photometric eccentricities of individual transiting planets

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    Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the "cold" Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial velocity follow-up of most. Here we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star's density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations -- part of the "photoeccentric" light curve signature of a planet's eccentricity --- even with long-cadence Kepler photometry and loosely-constrained stellar parameters. A Markov Chain Monte Carlo exploration of parameter posteriors naturally marginalizes over the periapse angle and automatically accounts for the transit probability. To demonstrate, we use three published transit light curves of HD 17156 b to measure an eccentricity of e = 0.71 +0.16/-0.09, in good agreement with the discovery value e = 0.67+/-0.08 based on 33 radial-velocity measurements. We present two additional tests using actual Kepler data. In each case the technique proves to be a viable method of measuring exoplanet eccentricities and their confidence intervals. Finally, we argue that this method is the most efficient, effective means of identifying the extremely eccentric, proto hot Jupiters predicted by Socrates et al. (2012).Comment: ApJ, 756, 122. Received 2012 April 5; accepted 2012 July 9; published 2012 August 2

    Diverging Discourses: Animal Health Challenges and Veterinary Care in Northern Uganda

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    People in northern Uganda are currently rebuilding their lives after a lengthy period of conflict. To facilitate this, the Ugandan government and donors have promoted investment in pigs as an important strategy for generating income quickly and ensuring livelihood security. In this context, animal health issues are an acknowledged challenge, creating uncertainty for animal owners who risk losing both their animals and income. This paper draws on policy documents guiding the veterinary sector, interviews with faculty staff at Makerere University and with veterinarians and paraprofessionals in northern Uganda, and ethnographic fieldwork in smallholder communities. The aims of this study were to contribute to an understanding of the structure of veterinary support and its dominant development narratives in policy and veterinary education and of the way in which dominant discourses and practices affect smallholders' ability to treat sick animals. Particular attention was paid to the role of paraprofessionals, here referring to actors with varied levels of training who provide animal health services mainly in rural areas. The results suggest that veterinary researchers, field veterinarians and government officials in agricultural policy share a common discourse in which making smallholders more business-minded and commercializing smallholder production are important elements in reducing rural poverty in Uganda. This way of framing smallholder livestock production overlooks other important challenges faced by smallholders in their livestock production, as well as alternative views of agricultural development. The public veterinary sector is massively under-resourced; thus while inadequately trained paraprofessionals and insufficient veterinary support currently present a risks to animal health, paraprofessionals fulfill an important role for smallholders unable to access the public veterinary sector. The dominant discourse framing paraprofessionals as "quacks" tends to downplay how important they are to smallholders by mainly highlighting the negative outcomes for animal healthcare resulting from their lack of formalized training. The conclusions of this study are that both animal health and smallholders' livelihoods would benefit from closer collaboration between veterinarians and paraprofessionals and from a better understanding of smallholders' needs
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