Simple single-scale microstructures based on optimal rank-3 laminates

With the goal of identifying optimal elastic single-scale microstructures for multiple loading situations, the paper shows that qualified starting guesses, based on knowledge of optimal rank-3 laminates, significantly improves chances of convergence to near optimal designs. Rank-3 laminates, optimal for a given set of anisotropic loading conditions, are approximated on a single scale using a simple mapping approach. We demonstrate that these mapped microstructures perform relatively close to theoretical energy bounds. Microstructures with a performance even closer to the bounds can be obtained by using the approximated rank-3 structures in a further step as starting guesses for inverse homogenization problems. Due to the nonconvex nature of inverse homogenization problems, the starting guesses based on rank-3 laminates outperform classical starting guesses with homogeneous or random material distributions. Furthermore, the obtained single-scale microstructures are relatively simple, which enhances manufacturability. Results, obtained for a wide range of loading cases, indicate that microstructures with performance within 5–8% of the theoretical optima can be guarantied, as long as feature sizes are not limited by minimium size constraints.

     

Performance and programmability comparison of the thick control flow architecture and current multicore processors

The Journal of Supercomputing - Commercial multicore central processing units (CPU) integrate a number of processor cores on a single chip to support parallel execution of computational tasks....     

Effects of feeding unlimited amounts of milk replacer for the first 5 weeks of age on rumen and small intestinal growth and development in dairy calves

The development of the gastrointestinal tract in newborn calves is essential for sufficient nutrient uptake. An intensive milk feeding during the neonatal period may impair the rumen development in calves. The aim of this study was to investigate effects of milk replacer (MR) feeding in unlimited amounts for the first 5 wk of age on the gastrointestinal growth and development in preruminant calves at wk 9 of age. Twenty-eight newborn Holstein and Holstein × Charolais crossbred calves (19 male and 9 female) were fed MR ad libitum (ADLIB) or in restricted amounts (6 L per day; RES) until wk 5 of age. Thereafter, the MR intake of ADLIB was gradually reduced at wk 6 and 7, and all calves received 6 L of MR per day until wk 9 of age. In wk 9, calves were slaughtered and carcass and organ weight as well as rumen papilla size in the atrium, ventral sac, and ventral blind sac, and villus size of the mucosa in the small intestine (duodenum; proximal, mid, and distal jejunum; and ileum) were determined. The expression of mRNA associated with the local insulin-like growth factor (IGF) system was measured in the rumen epithelium. Ad libitum MR feeding increased MR intake and growth in ADLIB without influencing concentrate intake compared with RES. Carcass weight in wk 9 was greater in ADLIB than in RES. The density of the rumen papillae in the atrium and ventral blind sac was greater in RES than in ADLIB calves, but surface area of the epithelium was not different between groups in the investigated regions of the rumen. The mRNA abundance of IGF1 in the atrium tended to be greater and the IGFR1 mRNA abundance in the ventral sac tended to be lower in the ADLIB than in the RES feeding group. The rumen pH and volatile fatty acid concentrations were not affected by MR feeding intensity. In mid-jejunum, villus circumference was greater in ADLIB than in RES calves. In the distal jejunum, villus surface area and the villus height/crypt depth ratio were greater and the villus circumference and height tended to be greater, whereas crypt depth was smaller in ADLIB than in RES calves. The findings from this study indicate that ad libitum MR feeding for 5 wk of age followed by its gradual reduction promotes growth performance without any negative influence on gastrointestinal growth and development in dairy calves at 9 wk of age.     

Compliance in quality of life data: a Norwegian experience

Compliance is of extreme importance in assessing quality of life since lost data never can be retrieved. In order to assess this issue in various studies, a cross-sectional study in cured cancer patients, three prospective trials and a normative study were explored. In the cross-sectional study 82 per cent of the patients completed the questionnaires after one reminder. More females than males answered the questionnaires. The compliance rate varied from 99 per cent to 62 per cent in the prospective studies depending upon time after inclusion. It seems that compliance decreases during follow up, primarily because of disease progression. In one of the prospective studies low compliance rate (approximately 30 per cent) was found in the questionnaire assessing religious issues. In the normative study 68 per cent of the population completed the questionnaire. No gender differences were found, but younger males and elderly women were poor compliers. In conclusion, our data support that most patients complete quality of life questionnaires. It seems that patients with inferior education, reduced physical function and with progressive/terminal disease are low compliers. Introduction of the first quality of life questionnaires to the patients is of great importance. Detailed information about the study should be given and the importance of completing the questionnaires should be underlined.     

Increased muscle fatty acid oxidation in dairy cows with intensive body fat mobilization during early lactation

The beginning of lactation requires huge metabolic adaptations to meet increased energy demands for milk production of dairy cows. One of the adaptations is the mobilization of body reserves mainly from adipose tissue as reflected by increased plasma nonesterified fatty acid (NEFA) concentrations. The capacity of the liver for complete oxidation of NEFA is limited, leading to an increased formation of ketone bodies, reesterification, and accumulation of triglycerides in the liver. As the skeletal muscle also may oxidize fatty acids, it may help to decrease the fatty acid load on the liver. To test this hypothesis, 19 German Holstein cows were weekly blood sampled from 7 wk before until 5 wk after parturition to analyze plasma NEFA concentrations. Liver biopsies were obtained at d 3, 18, and 30 after parturition and, based on the mean liver fat content, cows were grouped to the 10 highest (HI) and 9 lowest (LO). In addition, muscle biopsies were obtained at d −17, 3, and 30 relative to parturition and used to quantify mRNA abundance of genes involved in fatty acid degradation. Plasma NEFA concentrations peaked after parturition and were 1.5-fold higher in HI than LO cows. Muscle carnitine palmitoyltransferase 1α and β mRNA was upregulated in early lactation. The mRNA abundance of muscle peroxisome proliferator-activated receptor γ (PPARG) increased in early lactation and was higher in HI than in LO cows, whereas the abundance of PPARA continuously decreased after parturition. The mRNA abundance of muscle PPARD, uncoupling protein 3, and the β-oxidative enzymes 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase, very long-chain acyl-CoA dehydrogenase, and 3-ketoacyl-CoA was greatest at d 3 after parturition, whereas the abundance of PPARγ coactivator 1α decreased after parturition. Our results indicate that around parturition, oxidation of fatty acids in skeletal muscle is highly activated, which may contribute to diminish the fatty acid load on the liver. The decline in muscle fatty acid oxidation within the first 4 wk of lactation accompanied with increased feed intake refer to greater supply of ruminally derived acetate, which as the preferred fuel of the muscle, saves long-chain fatty acids for milk fat production.     

Variable liver fat concentration as a proxy for body fat mobilization postpartum has minor effects on insulin-induced changes in hepatic gene expression related to energy metabolism in dairy cows

The liver plays a central role in adaptation for energy requirements around calving, and changes in the effects of insulin on hepatic energy metabolism contribute to metabolic adaptation in dairy cows. Hepatic insulin effects may depend on body fat mobilization. The objective of this study was to investigate the effects of insulin on the hepatic gene expression of enzymes involved in energy metabolism and factors related to nutrition partitioning in cows with high and low total liver fat concentration (LFC) after calving. Holstein cows were retrospectively grouped according to their LFC after calving as a proxy for body fat mobilization. Cows were classified as low (LLFC; LFC <24% fat/dry matter; n = 9) and high (HLFC; LFC >24.4% fat/dry matter; n = 10) fat-mobilizing after calving. Euglycemic-hyperinsulinemic clamps [6 mU/(kg × min) of insulin for 6 h] were performed in wk 5 antepartum (ap) and wk 3 postpartum (pp). Before and at the end of the euglycemic-hyperinsulinemic clamps, liver biopsies were taken to measure the mRNA abundance of enzymes involved in carbohydrate and lipid metabolism, expression related to the somatotropic axis, and adrenergic and glucocorticoid receptors. The mRNA abundance of pyruvate carboxylase, cytosolic phosphoenolpyruvate carboxykinase (PEPCK; PCK1), acyl-CoA-dehydrogenase very long chain (ACADVL), and hydroxyl-methyl-glutaryl-CoA-synthase 1 increased, but the mRNA abundance of solute carrier family 2 (SLC2A2 and SLC2A4), growth hormone receptor 1A (GHR1A), insulin-like growth factor 1 (IGF1), sterol regulatory element binding factor 1, adrenoceptor α 1A, and glucocorticoid receptor decreased from ap to pp. Insulin treatment was associated with decreased PCK1, mitochondrial PEPCK, glucose-6-phosphatase, propionyl-CoA-carboxylase α, carnitine-palmitoyl-transferase 1A, ACADVL, and insulin receptor mRNA, but increased IGF1 and SLC2A4 mRNA ap and pp and GHR1A mRNA pp. The mRNA abundance of SLC2A4 was greater, and the mRNA abundance of GHR1A and IGF1 tended to be lower in LLFC than in HLFC. Administration of insulin, albeit at a supraphysiological dose, was associated with inhibition of gene expression related to glucose production and β-oxidation, but we observed variable effects in the degree of insulin depression of individual genes. Insulin status is important for regulation of nutrient partitioning, but different LFC pp had very little influence on changes in hepatic gene expression following administration of insulin.     

Measurement of health-related quality of life in malignant diseases. Does it have any consequences?

The traditional end points of clinical trials in malignant disease are response, disease-free survival, and overall survival. Because a substantial part of cancer treatment is palliative, health-related quality of life should be a major objective in clinical trials. Cancer specific questionnaires, which measure the various quality of life domains and which are tested for reliability, validity and sensitivity to changes in clinical status, are now available. Measurement of health-related quality of life may lead to important conclusions. For instance, results from a Nordic myeloma trial suggest that obtaining an objective response is not a prerequisite for achieving an improved quality of life. They also indicate that the 5 to 6 month plateau phase prolongation obtained by giving interferon alpha-2b in addition to melphalan/prednisone is not associated with any quality of life benefit. Data from the same trial are used to illustrate how quality of life data can be utilized in cost-utility analysis: the cost per quality adjusted life year (QALY) gained by adding interferon was estimated at USD 110,000.