Computer program resolves radiative, conductive, and convective heat transfer problems for variety of geometries

Computer program computes temperature distribution as a function of time in a given body which has been subdivided into a network of nodes. Thermal resistances and capacitances may be computed from nodal geometry

The a-number of hyperelliptic curves

It is known that for a smooth hyperelliptic curve to have a large $a$-number, the genus must be small relative to the characteristic of the field, $p>0$, over which the curve is defined. It was proven by Elkin that for a genus $g$ hyperelliptic curve $C$ to have $a_C=g-1$, the genus is bounded by $g<\frac{3p}{2}$. In this paper, we show that this bound can be lowered to $g <p$. The method of proof is to force the Cartier-Manin matrix to have rank one and examine what restrictions that places on the affine equation defining the hyperelliptic curve. We then use this bound to summarize what is known about the existence of such curves when $p=3,5$ and $7$.Comment: 7 pages. v2: revised and improved the proof of the main theorem based on suggestions from the referee. To appear in the proceedings volume of Women in Numbers Europe-

Weak efficiency test in the colombian stock market

Este trabajo prueba la hipótesis de eficiencia débil al comprobar la hipótesis de martingala en diferencias en los retornos del Índice General de la Bolsa de Valores de Colombia, IGBC. Se considera una estructura de dependencia condicional de primer orden mediante el modelo auto-regresivo fraccionalmente integrado de medias móviles, ARFIMA, y de segundo orden con el modelo hiperbólico asimétrico potencial autorregresivo condicionalmente heterocedástico, HYAPARCH, el cual captura todos los hechos estilizados encontrados en la investigación empírica. Los resultados rechazan la hipótesis de eficiencia débil al mostrar que el proceso generador de los retornos parece obedecer a un modelo auto-regresivo fraccionalmente integrado, arfi, en media condicional y a un hiperbólico asimétrico autorregresivo condicionalmente heterocedástico, HYAGARCH, en varianza condicional.This paper proves the weak efficiency hypothesis when proving the maritingala hypothesis on return differences for the General Index of the Colombian Stock Exchange (IGBC) . A first order conditional dependency structure by using the Autoregressive Fractionally Integrated Moving Averages model ARFIMA, and on second order with the Hyperbolical Asymmetric Autoregressive Potential Conditionally Heteroscedastic model, HYAPARCH, which captures all the stylized facts in the empiric research is considered. The results reject the weak efficiency hypothesis when showing that the returns generation process seems to obey to and Autoregressive Fractionally Integrated model ARFI in conditional average anda Hyperbolical Asymmetric Conditionally Heteroscedastic model, HYAGARCH, in conditional variance.Este trabalho prova a hipótese de eficiência débil ao comprovar a hipótese de Gamarra em diferenças nas voltas do Índice Geral da Bolsa de Valores da Colômbia, IGBC. Considera-se uma estrutura de dependência condicional de primeiro ordem mediante o modelo Auto-regressivo Fraccionalmente Integrado de Médias Móveis,ARFIMA, e de segundo ordem com o modelo Hiperbólico Assimétrico Potencial Auto-regressivo Condicionalmente Heterocedástico, HYAPARCH, o qual captura todos os fatos estilizados encontrados na investigação empírica. Os resultados recusam a hipótese de eficiência débil ao mostrar que o processo gerador dasvoltas parece obedecer a um modelo Auto-regressivo Fraccionado Integrado, ARFI, em média condicional e a um Hiperbólico Assimétrico Auto-regressivo Condicionalmente Heterocedástico, HYAGARCH, em variância condiciona

Six questions on the construction of ontologies in biomedicine

(Report assembled for the Workshop of the AMIA Working Group on Formal Biomedical Knowledge Representation in connection with AMIA Symposium, Washington DC, 2005.) Best practices in ontology building for biomedicine have been frequently discussed in recent years. However there is a range of seemingly disparate views represented by experts in the field. These views not only reflect the different uses to which ontologies are put, but also the experiences and disciplinary background of these experts themselves. We asked six questions related to biomedical ontologies to what we believe is a representative sample of ontologists in the biomedical field and came to a number conclusions which we believe can help provide an insight into the practical problems which ontology builders face today

Toxicant-Induced Leakage of Germ Cell–Specific Proteins from Seminiferous Tubules in the Rat: Relationship to Blood-Testis Barrier Integrity and Prospects for Biomonitoring

Evaluation of testicular toxicity during drug development is currently based on histopathological evaluation. A sensitive biomarker for testicular toxicology could provide an in-life and “early warning” measurement. Previous studies suggested that disruption of spermatogenesis induced leakage of germ cell proteins from seminiferous tubules (STs) into interstitial fluid (IF); such proteins have potential for use as biomarkers. To investigate this possibility further, adult male rats were treated with three testicular toxicants thought to have differing sites of action; cadmium chloride affects the blood-testis barrier (BTB), methoxyacetic acid (MAA) disrupts pachytene spermatocytes, and 1,3-dinitrobenzene (DNB) targets Sertoli cells. IF proteins were assessed by Coomassie-based dye-stained gels. Immunostaining was used to identify toxicant-induced damage (DAZL) and BTB integrity (ZO-1, occludin, N-cadherin, and β-catenin) and function (biotin). Cadmium chloride induced dose-dependent leakage of proteins from STs into IF coincident with loss of integrity and function of the BTB. Two of the “leaked” proteins were identified on Westerns as being germ cell specific, namely VASA and fatty acid–binding protein 9 (FABP9). In contrast, similar protein leakage was not evident after either MAA-induced or DNB-induced disruption of spermatogenesis and neither of these treatments affected BTB integrity or function. These results suggest that loss of BTB integrity is required for germ cell–specific proteins to leak from STs into IF, implying that use of such biomarkers has very limited potential for noninvasive monitoring of compound-induced disruption to spermatogenesis