507 research outputs found

    The influence of vehicle aerodynamic and control response characteristics on driver-vehicle performance

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    The effects of changes in understeer, control sensitivity, and location of the lateral aerodynamic center of pressure (c.p.) of a typical passenger car on the driver's opinion and on the performance of the driver-vehicle system were studied in a moving-base driving simulator. Twelve subjects with no prior experience on the simulator and no special driving skills performed regulation tasks in the presence of both random and step wind gusts

    The use of a battery of tracking tests in the quantitative evaluation of neurological function

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    A tracking test battery has been applied in a drug trail designed to compare the efficacy of L-DOPA and amantadine to that of L-DOPA and placebo in the treatment of 28 patients with Parkinson's disease. The drug trial provided an ideal opportunity for objectively evaluating the usefulness of tracking tests in assessing changes in neurologic function. Evaluating changes in patient performance resulting from disease progression and controlled clinical trials is of great importance in establishing effective treatment programs

    Effect of genotype and hens' starting body fat content on the changes in the body fat content of the hens and on the weight and composition of the eggs produced in the first egg laying period

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    The aim of this study was to examine the effect of genotype and hens’ starting body fat content on the changes in the body fat content of the hens and on the weight and composition of the eggs produced in the first egg laying period. The experiment was carried out with altogether 30 hens (15 TETRA SL brown egg layers and 15 TETRA BLANCA white egg layers), which were chosen from altogether 45 TETRA SL and 45 TETRA BLANCA hens based on their CT (computer tomography) predicted body fat content at 20 weeks of age (hens with the highest (n=5), hens with the lowest (n=5) and hens with average (n=5) body fat content in both genotype). For the in vivo determination of changes in the body composition of these hens, computer tomography (CT) measurements were carried out at every fourth week between the 20th and 72nd week of age. During the CT measurements hens were fixed with belts in a special plexiglass container without using any anaesthetics. The measurements covered the whole body of the hens using overlapping 10 mm slice thickness on a Siemens Somatom Emotion 6 multislice CT scanner. After collecting, weighing and breaking the eggs produced by the experimental birds on the days of the CT measurements their yolk ratio was determined. Based on the results, it was established that the body fat content of the hens increased continuously in both of the genotypes in the first phase of the experimental period, while it did not change further in the second phase of the experiment. It was also observed at all examination days, that the body fat content of the white egg layers was higher than that of the brown egg layers. Hens with the highest starting body fat content had the highest body fat content in both genotypes during the whole egg laying period. The egg production of the hens was not influenced by the body fat content of the birds, but it was affected by the genotype. The TETRA SL hens produced significantly more eggs than the TETRA BLANCA hens. The hens with average body fat content produced lighter eggs than the hens with low or high body fat content

    Activation of Human Stearoyl-Coenzyme A Desaturase 1 Contributes to the Lipogenic Effect of PXR in HepG2 Cells

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    The pregnane X receptor (PXR) was previously known as a xenobiotic receptor. Several recent studies suggested that PXR also played an important role in lipid homeostasis but the underlying mechanism remains to be clearly defined. In this study, we found that rifampicin, an agonist of human PXR, induced lipid accumulation in HepG2 cells. Lipid analysis showed the total cholesterol level increased. However, the free cholesterol and triglyceride levels were not changed. Treatment of HepG2 cells with rifampicin induced the expression of the free fatty acid transporter CD36 and ABCG1, as well as several lipogenic enzymes, including stearoyl-CoA desaturase-1 (SCD1), long chain free fatty acid elongase (FAE), and lecithin-cholesterol acyltransferase (LCAT), while the expression of acyl:cholesterol acetyltransferase(ACAT1) was not affected. Moreover, in PXR over-expressing HepG2 cells (HepG2-PXR), the SCD1 expression was significantly higher than in HepG2-Vector cells, even in the absence of rifampicin. Down-regulation of PXR by shRNA abolished the rifampicin-induced SCD1 gene expression in HepG2 cells. Promoter analysis showed that the human SCD1 gene promoter is activated by PXR and a novel DR-7 type PXR response element (PXRE) response element was located at -338 bp of the SCD1 gene promoter. Taken together, these results indicated that PXR activation promoted lipid synthesis in HepG2 cells and SCD1 is a novel PXR target gene. © 2013 Zhang et al

    Quantitative evaluation of neuropharmacological trials

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116906/1/cpt1974153229.pd

    Is Environmental Improvement in Automotive Component Design Highly Constrained?

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    This article investigates the influence of environmental, cost, and performance requirements on the design and management of automotive components through a case study involving instrument panels. To address the question of whether the environmental improvement of an instrument panel (IP) is highly constrained, a lifecycle inventory analysis is used to characterize the major environmental burdens associated with a generic IP defined from an average of three midsized vehicle models. A life-cycle cost analysis is also conducted to understand the market forces operating in the domains of the original equipment manufacturer; consumer; and end-of-life (EOL) vehicle managen. This study indicates that the existing set of environmental requirements, in conjunction with current cost drivers and the large set of manufacturing and use phase functional performance requirements, highly constrain opportunities for environmental improvement Specific improvement strategies-lightweighting, elimination of the painting operation, and reduction in material complexity-are examined in the context of existing system requirements. The near-term forecast for improvements is not optimistic. Innovation will continue in a slow and piecemeal fashion until requirements affecting the total vehicle system are significantly changedPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72780/1/jiec.1998.2.2.103.pd

    Effect of genotype and hens' starting body fat content on the changes in the body fat content of the hens and on the weight and composition of the eggs produced in the first egg laying period

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    The aim of this study was to examine the effect of genotype and hens’ starting body fat content on the changes in the body fat content of the hens and on the weight and composition of the eggs produced in the first egg laying period. The experiment was carried out with altogether 30 hens (15 TETRA SL brown egg layers and 15 TETRA BLANCA white egg layers), which were chosen from altogether 45 TETRA SL and 45 TETRA BLANCA hens based on their CT (computer tomography) predicted body fat content at 20 weeks of age (hens with the highest (n=5), hens with the lowest (n=5) and hens with average (n=5) body fat content in both genotype). For the in vivo determination of changes in the body composition of these hens, computer tomography (CT) measurements were carried out at every fourth week between the 20th and 72nd week of age. During the CT measurements hens were fixed with belts in a special plexiglass container without using any anaesthetics. The measurements covered the whole body of the hens using overlapping 10 mm slice thickness on a Siemens Somatom Emotion 6 multislice CT scanner. After collecting, weighing and breaking the eggs produced by the experimental birds on the days of the CT measurements their yolk ratio was determined. Based on the results, it was established that the body fat content of the hens increased continuously in both of the genotypes in the first phase of the experimental period, while it did not change further in the second phase of the experiment. It was also observed at all examination days, that the body fat content of the white egg layers was higher than that of the brown egg layers. Hens with the highest starting body fat content had the highest body fat content in both genotypes during the whole egg laying period. The egg production of the hens was not influenced by the body fat content of the birds, but it was affected by the genotype. The TETRA SL hens produced significantly more eggs than the TETRA BLANCA hens. The hens with average body fat content produced lighter eggs than the hens with low or high body fat content

    Body composition and venison quality of farmed red deer (<i>Cervus elaphus</i>) hinds reared on grass, <i>papilionaceous</i> or mixed pasture paddocks

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    Red deer (Cervus elaphus) hinds (n=3×10) of identical initial body weight (BW, ca. 68&thinsp;kg) were reared on a monocotyledonous grass (G group), on a grass–papilionaceous (GP group) or on pure papilionaceous pasture each of 2&thinsp;ha (P group) for 219 d. At the end of the experiment carcass tissue composition was assessed by means of computer tomography, slaughter value and meat quality were characterized and tissue – longissimus thoracis et lumborum (LTL), thigh and liver – samples were taken for fatty acid composition analysis. The primary aim was to assess nutrition-driven differences. Hinds of group P provided higher final BW (101&thinsp;kg vs. 90 and 91.9&thinsp;kg in groups G and GP, respectively) and higher BW gain (32.6&thinsp;kg during the total period vs. 22.4 and 22.1&thinsp;kg). The carcass weight exceeded those of the other groups significantly (68.8&thinsp;kg vs. 59.3 and 63.2&thinsp;kg), while there was no difference among groups in the perirenal fat weight and red color tone (a*) of the LTL. Groups G and P differed significantly in the LTL weight (highest in P), its dripping loss (lowest in G), lightness (L; highest in P) and yellow color tone (b*). In the thigh muscle, LTL and liver the highest proportion of fatty acid CLA9c11t was reached on the G pasture, and the same trend was true for docosahexaenoic acid (DHA , C22:6 n3) in the muscles. The n6&thinsp;∕&thinsp;n3 fatty acid ratio was the highest on the P pasture in the liver and both muscles. The liver incorporated the highest proportion of linoleic acid (C18:2 n6) and converted it rather effectively to arachidonic acid (C20:4 n6), coupled with the lowest α-linolenic acid presence. In conclusion, concerning muscle mass production, group P proved to be the most advantageous pasture; meanwhile LTL meat quality factors (dripping loss, DHA proportion, pH, color) were more favorable on the G pasture.</p
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