2,775 research outputs found
Constructing Employability Indicators for Enhancing the Effectiveness of Engineering Education for the Solar Industry
The aim of this research is to establish a set of employability indicators that capture the competency requirements and performance expectations that solar energy enterprises have of their employees. In the qualitative component of the study, 12 administrators and 32 engineers in the industry were interviewed, and meetings with focus groups were conducted to formulate a questionnaire for a survey of Taiwanese solar energy companies for the confirmation and prioritisation of the employability indicators. On the basis of the results of the quantitative component, an interpretational model relating competence, job performance, working attitude, and employability for solar corporation recruitment and training purposes as well as for school curricular development was developed. The interpretation model formulated effectively interprets the relationship between solar enterprises’ expectations and students’ employability. The research contributes a framework for the selection and cultivation of talent, as well as providing a basis for fundamental development of the solar engineering curriculum
FFTPL: An Analytic Placement Algorithm Using Fast Fourier Transform for Density Equalization
We propose a flat nonlinear placement algorithm FFTPL using fast Fourier
transform for density equalization. The placement instance is modeled as an
electrostatic system with the analogy of density cost to the potential energy.
A well-defined Poisson's equation is proposed for gradient and cost
computation. Our placer outperforms state-of-the-art placers with better
solution quality and efficiency
Histamine metabolism influences blood vessel branching in zebrafish reg6 mutants
<p>Abstract</p> <p>Background</p> <p>Vascular branching morphogenesis is responsible for the extension of blood vessels into growing tissues, a process crucial for organogenesis. However, the genetic mechanism for vessel branching is largely unknown. Zebrafish <it>reg6 </it>is a temperature-sensitive mutation exhibiting defects in blood vessel branching which results in the formation of swollen vessel lumina during capillary plexus formation.</p> <p>Results</p> <p>We performed a screening for chemical suppressors of <it>reg6 </it>and identified SKF91488, an inhibitor of histamine methyltransferase (HMT), that can rescue the <it>reg6 </it>vessel branching defects in a dose-dependent manner. Inhibition of HMT by SKF91488 presumably blocks histamine degradation, thus causing histamine accumulation. Consistent with this idea, we found that a high level of histamine also showed significant suppression of <it>reg6 </it>vessel phenotypes. Interestingly, when <it>reg6 </it>adults that had already developed swollen vessel lumina in regenerating fins were treated with histamine or SKF91488, either treatment significantly reduced the number of swollen vessels within 12 h, suggesting a rapid and constant influence of histamine on blood vessel branching. Furthermore, the expression of HMT was significantly elevated in <it>reg6 </it>regenerating fins. Conversely, lowering histamine by administering urocanic acid, a histidine decarboxylase inhibitor, enhanced the <it>reg6 </it>phenotypes. Finally, we identified that the transcription factor, egr-1 (early growth response factor 1), was closely associated with the <it>reg6 </it>phenotype and chemical treatments.</p> <p>Conclusion</p> <p>Taken together, our results suggest that blood vessel branching is influenced by histamine metabolism, possibly through regulating the expression of the egr-1 transcription factor.</p
Kernel Estimation of Rate Function for Recurrent Event Data
Recurrent event data are largely characterized by the rate function but smoothing techniques for estimating the rate function have never been rigorously developed or studied in statistical literature. This paper considers the moment and least squares methods for estimating the rate function from recurrent event data. With an independent censoring assumption on the recurrent event process, we study statistical properties of the proposed estimators and propose bootstrap procedures for the bandwidth selection and for the approximation of confidence intervals in the estimation of the occurrence rate function. It is identified that the moment method without resmoothing via a smaller bandwidth will produce curve with nicks occurring at the censoring times, whereas there is no such problem with the least squares method. Furthermore, the asymptotic variance of the least squares estimator is shown to be smaller under regularity conditions. However, in the implementation of the bootstrap procedures, the moment method is computationally more efficient than the least squares method because the former approach uses condensed bootstrap data. The performance of the proposed procedures is studied through Monte Carlo simulations and an epidemiological example on intravenous drug users
The cholesterol-hydroxyecdysone-vitellogenin pathway is involved in the longevity of trophocytes and oenocytes of queen honey bees (Apis mellifera)
International audienceAbstractTrophocytes and oenocytes in the abdomen of honey bees do not divide after eclosion; however, trophocytes and oenocytes of queen bees have a longer lifespan and maintain better cellular function than those of worker bees. To explore this phenomenon, we assayed the molecules involved in the cholesterol-hydroxyecdysone-vitellogenin (Vg) pathway in the trophocytes and oenocytes of young and old worker and queen bees. The results showed that Vg and cholesterol levels in hemolymph and cholesterol levels, 20-hydroxyecdysone (20E) levels, and the messenger RNA levels of cytochrome P450 314A1 20-hydroxylase (Cyp314A1), ecdysone receptor isoform A (EcR-A), ecdysone receptor isoform B1 (EcR-B1), ultraspiracle (USP), ecdysone-induced protein 74 (E74), ecdysone-induced protein 75 (E75), broad-complex (BR-C), Vg, and Vg receptor (VgR) in trophocytes and oenocytes were increased in queen bees compared with worker bees. These findings indicated that queen bees have higher expression of molecules in the cholesterol-hydroxyecdysone-Vg pathway than worker bees
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