An adaptive pseudo-spectral method for reaction diffusion problems

The spectral interpolation error was considered for both the Chebyshev pseudo-spectral and Galerkin approximations. A family of functionals I sub r (u), with the property that the maximum norm of the error is bounded by I sub r (u)/J sub r, where r is an integer and J is the degree of the polynomial approximation, was developed. These functionals are used in the adaptive procedure whereby the problem is dynamically transformed to minimize I sub r (u). The number of collocation points is then chosen to maintain a prescribed error bound. The method is illustrated by various examples from combustion problems in one and two dimensions

Determinants of incident vulvovaginal candidiasis in human immunodeficiency virus-positive women.

OBJECTIVE: Mucosal infections including vulvovaginal candidiasis are a common problem for women with human immunodeficiency virus (HIV) infection. Our objective was to determine which factors predict the development of symptomatic disease among HIV-infected women. MATERIALS AND METHODS: In a prospective study from 1991 to 1995, 205 HIV-positive women were evaluated every 6 months for occurrences of vulvovaginal candidiasis. Included in the study were all initially asymptomatic women, whether they were fungal-culture-positive or -negative at baseline. Excluded from the study were all women with symptomatic vulvovaginal candidiasis at the initial visit, those who developed trichomonas vaginitis at any visit, and those who used any antifungal agents. RESULTS: The risk of the development of vulvovaginal candidiasis did not differ between women who were asymptomatically colonized at baseline and those who were fungal-culture-negative. However, the risk of developing vulvovaginal candidiasis was increased 6.8 times for women with CD4 counts less than 200 cells/mm3 at baseline. CONCLUSIONS: Fungal culture is not predictive of the development of symptomatic vulvovaginal candidiasis. Women infected with HIV who have CD4 counts below 200 cells/mm3 should be monitored more carefully for vulvovaginal candidiasis

Rapid oligo-galacturonide induced changes in protein phosphorylation in arabidopsis

The wall-associated kinases (WAKs)1 are receptor protein kinases that bind to long polymers of cross-linked pectin in the cell wall. These plasma-membrane-associated protein kinases also bind soluble pectin fragments called oligo-galacturonides (OGs) released from the wall after pathogen attack and damage. WAKs are required for cell expansion during development but bind water soluble OGs generated from walls with a higher affinity than the wall-associated polysaccharides. OGs activate a WAKdependent, distinct stress-like response pathway to help plants resist pathogen attack. In this report, a quantitative mass-spectrometric-based phosphoproteomic analysis was used to identify Arabidopsis cellular events rapidly induced by OGs in planta. Using N14/ N15 isotopic in vivo metabolic labeling, we screened 1,000 phosphoproteins for rapid OG-induced changes and found 50 proteins with increased phosphorylation, while there were none that decreased significantly. Seven of the phosphosites within these proteins overlap with those altered by another signaling molecule plants use to indicate the presence of pathogens (the bacterial elicitor peptide Flg22), indicating distinct but overlapping pathways activated by these two types of chemicals. Genetic analysis of genes encoding 10 OG-specific and two Flg22/OG-induced phosphoproteins reveals that null mutations in eight proteins compromise the OG response. These phosphorylated proteins with genetic evidence supporting their role in the OG response include two cytoplasmic kinases, two membrane-associated scaffold proteins, a phospholipase C, a CDPK, an unknown cadmium response protein, and a motor protein. Null mutants in two proteins, the putative scaffold protein REM1.3, and a cytoplasmic receptor like kinase ROG2, enhance and suppress, respectively, a dominant WAK allele. Altogether, the results of these chemical and genetic experiments reveal the identity of several phosphorylated proteins involved in the kinase/ phosphatase-mediated signaling pathway initiated by cell wall changes

Improving the Performance of Tensor Matrix Vector Multiplication in Quantum Chemistry Codes.

Cumulative reaction probability (CRP) calculations provide a viable computational approach to estimate reaction rate coefficients. However, in order to give meaningful results these calculations should be done in many dimensions (ten to fifteen). This makes CRP codes memory intensive. For this reason, these codes use iterative methods to solve the linear systems, where a good fraction of the execution time is spent on matrix-vector multiplication. In this paper, we discuss the tensor product form of applying the system operator on a vector. This approach shows much better performance and provides huge savings in memory as compared to the explicit sparse representation of the system matrix

Argonne National Laboratory Reports

DISPL is a software package for solving some second-order nonlinear systems of partial differential equations including parabolic, elliptic, hyperbolic, and some mixed types such as parabolic-elliptic equations. Fairly general nonlinear boundary conditions are allowed as well as interface conditions for problems in an inhomogeneous media. The spatial domain is one- or two-dimensional with Cartesian, cylindrical, or spherical (in one dimension only) geometry. The numerical method is based on the use of Galerkin's procedure combined with the use of B-splines in order to reduce the system of PDE's to a system of ODE's. The latter system is then solved with a sophisticated ODE software package. Software features include extensive dump/restart facilities, free format input, moderate printed output capability, dynamic storage allocation, and three graphics packages

Simulación de la formación de canales de mareas por medio de autómatas celulares y fractales

El objetivo de este trabajo es estudiar y simular la interacción entre los agentes biológicos responsables de modificar el paisaje de las marismas e influir en la formación de canales de marea, en particular el cangrejo Chasmagnatus granulatus y la planta Sarcocornia perennis. La interacción entre la planta y el cangrejo se basa en leyes simples, pero cuyo resultado es un complejo mecanismo biológico que desemboca en un proceso erosivo sobre la marisma y favorece la formación de canales de marea (Escapa et. al. 2003). Estos tipos de problemas basados en leyes simples han sido modelados con buena precisión por modelos de Autómatas Celulares (Dunkerley 1997, Matsinos y Troumbis 2002, Aassine y El Jai 2002, Bandini y Pavesi, 2002 ). En particular se desea recrear las leyes observadas y medidas, para obtener una forma automática de reproducir las perturbaciones biológicas en el terreno y estudiar su efecto en la generación de canales de marea en base al estudio de un modelo digital de terreno resultante. Una simulación exitosa permitiría, entre otras cosas, predecir la formación de canales en lugares en donde sería peligroso o problemático (cercanía de rutas o poblaciones).Eje: Visualización y Computación gráficaRed de Universidades con Carreras en Informática (RedUNCI

The relation of plasmacytoid dendritic cells (pDCs) and regulatory t-cells (Tregs) with HPV persistence in HIV-Infected and HIV-Uninfected women

Other than CD4+ count, the immunologic factors that underlie the relationship of HIV/AIDS with persistent oncogenic HPV (oncHPV) and cervical cancer are not well understood. Plasmacytoid dendritic cells (pDCs) and regulatory T-cells (Tregs) are of particular interest. pDCs have both effector and antigen presenting activity and, in HIV-positive patients, low pDC levels are associated with opportunistic infections. Tregs downregulate immune responses, and are present at high levels in HIV-positives. The current pilot study shows for the first time that low pDC and high Treg levels may be significantly associated with oncHPV persistence in both HIV-positive and HIV-negative women. Larger studies are now warranted

Limiting the caesarean section rate in low risk pregnancies is key to lowering the trend of increased abdominal deliveries: an observational study

<p>Abstract</p> <p>Background</p> <p>As the rate of Caesarean sections (CS) continues to rise in Western countries, it is important to analyze the reasons for this trend and to unravel the underlying motives to perform CS. This research aims to assess the incidence and trend of CS in a population-based birth register in order to identify patient groups with an increasing risk for CS.</p> <p>Methods</p> <p>Data from the Flemish birth register 'Study Centre for Perinatal Epidemiology' (SPE) were used for this historic control comparison. Caesarean sections (CS) from the year 2000 (N = 10540) were compared with those from the year 2008 (N = 14016). By means of the Robson classification, births by Caesarean section were ordered in 10 groups according to mother - and delivery characteristics.</p> <p>Results</p> <p>Over a period of eight years, the CS rise is most prominent in women with previous sections and in nulliparous women with a term cephalic in spontaneous labor. The proportion of inductions of labor decreases in favor of elective CS, while the ongoing inductions of labor more often end in non-elective CS.</p> <p>Conclusions</p> <p>In order to turn back the current CS trend, we should focus on low-risk primiparae. Avoiding unnecessary abdominal deliveries in this group will also have a long-term effect, in that the number of repeat CS will be reduced in the future. For the purpose of self-evaluation, peer discussion on the necessity of CS, as well as accurate registration of the main indication for CS are recommended.</p