Orbiting binary black hole evolutions with a multipatch high order finite-difference approach

We present numerical simulations of orbiting black holes for around twelve cycles, using a high-order multipatch approach. Unlike some other approaches, the computational speed scales almost perfectly for thousands of processors. Multipatch methods are an alternative to AMR (adaptive mesh refinement), with benefits of simplicity and better scaling for improving the resolution in the wave zone. The results presented here pave the way for multipatch evolutions of black hole-neutron star and neutron star-neutron star binaries, where high resolution grids are needed to resolve details of the matter flow

Appraisal of the inherent socio-demographic dynamics of HIV/AIDS epidemic in four districts of South-Western Uganda

Although HIV prevalence in Uganda is much lower than it once was, AIDS is still claiming many lives each year with clear signs of escalating rural epidemics. The objective of this study was to appraise the socio-economic and demographic dynamics of HIV/AIDS epidemic in South-Western Uganda. Data were collected with standard closed ended semi-structured questionnaires self-administered to consenting, 605 HIV/AIDS patients, selected using the multistage random sampling technique, logistic linear regression, randomized block design and Pearson’s Chi square test (á=0.01) were used to analyse the data obtained. The duration of carriage was inversely proportional (r=-0.94) to population of HIV/AIDS patients surveyed. There were 98.2% Bantu (55.5% Banyankole and 22.6% Baganda); 77.5% females and 22.5% males; more widows (38.0%) than married (35.5%). HIV/AIDS prevalence generally decreased with increasinglevel of education. The highest (66.7%) HIV/AIDS prevalence was recorded in Bushenyi, followed by 58.4% in Masaka, 57.9% in Mbarara and 53.3% in Rukungiri. Rukungiri patients above 60 years of age harboured 57.1% HIV/AIDS followed by 45.5% among Masaka patients aged 11 - 20 years and 40% among Mbarara patients less than 10 years of age. HIV/AIDS prevalence was significantly (p<0.05) dependent on socio-economic and demographic factors of surveyed population. Therefore socio-economic and demographic factors underlie HIV/AIDS prevalence in this region. Observed differences in prevalence of HIV/AIDS between the surveyed districts wereremarkable and warrant regular surveillance for updated disease  epidemiology. Education can debunk the generally misconstrued rolesof social, economic and demographic factors in the spread of HIV/AIDS

Biosorption of heavy metal and dyes : a promising technology leather wastewater treatment

The presence of dyes and heavy metals is usual in industrial processes like chrome tanning in tannery industry and their removal may be an environmental problem. Different techniques were developed and applied for the treatment of dyes and heavy metals in effluents. Among them, adsorption showed to be an economic, simple operation and an effective technique. Zeolites have a strong affinity for cations of transition metals, but only little affinity for anions and non-polar organic molecules. The application of a zeolite to heavy metal removal may be improved by the presence of microorganisms. The aim of this work is the treatment of an effluent containing dyes and toxic metals. Several operation parameters such as pH, concentration and kinetic behavior were studied. This innovative process for treating dyes and heavy metal effluents showed that the zeolite-biomass system is able to perform the removal of a combination of Azure B and chromium(VI). A mixture of dye and metal solutions was treated reaching a removal higher than 50% in the case of chromium (VI) and higher than 99% for dye, in 8 days

Application of zeolite-Arthrobacter viscosus system for the removal of heavy metal and dye : chromium and azure B

A hybrid system combining the ion-exchange properties of a NaY zeolite and the characteristics of the bacterium Arthrobacter viscosus was investigated to treat polluted effluents with dye and toxic metals. In this study, the dye and the metal ion employed were a thiazine dye, Azure B, and chromium (VI), respectively. Initially, the removal of dye by the zeolite was tested. The analysis of dye equilibrium isotherms data was done using Langmuir, Freundlich, Sips and Redlich–Peterson models. Redlich–Peterson model gave the better fitting to data. In the dye adsorption studies, pseudo-second order kinetics showed the more reliable results. Operating at the optimised conditions in the treatment of single pollutants, a mixture of dye and metal solutions was treated reaching a removal higher than 50% for chromium (VI) and higher than 99% for dye, in 8 days.This work was supported by Fundacao para a Ciencia e Tecnologia (FCT-Portugal) and Xunta de Galicia under programme 08MDS034 314PR. The authors are grateful to University of Vigo for financial support of the research of Emilio Rosales under a mobility grant

Inactivation of the monofunctional peptidoglycan glycosyltransferase SgtB allows Staphylococcus aureus to survive in the absence of lipoteichoic acid

The cell wall of Staphylococcus aureus is composed of peptidoglycan and the anionic polymers lipoteichoic acid (LTA) and wall teichoic acid. LTA is required for growth and normal cell morphology in S. aureus. Strains lacking LTA are usually viable only when grown under osmotically stabilizing conditions or after the acquisition of compensatory mutations. LTA-negative suppressor strains with inactivating mutations in gdpP, which resulted in increased intracellular c-di-AMP levels, were described previously. Here, we sought to identify factors other than c-di-AMP that allow S. aureus to survive without LTA. LTA-negative strains able to grow in unsupplemented medium were obtained and found to contain mutations in sgtB, mazE, clpX, or vraT. The growth improvement through mutations in mazE and sgtB was confirmed by complementation analysis. We also showed that an S. aureus sgtB transposon mutant, with the monofunctional peptidoglycan glycosyltransferase SgtB inactivated, displayed a 4-fold increase in the MIC of oxacillin, suggesting that alterations in the peptidoglycan structure could help bacteria compensate for the lack of LTA. Muropeptide analysis of peptidoglycans isolated from a wild-type strain and sgtB mutant strain did not reveal any sizable alterations in the peptidoglycan structure. In contrast, the peptidoglycan isolated from an LTA-negative ltaS mutant strain showed a significant reduction in the fraction of highly cross-linked peptidoglycan, which was partially rescued in the sgtB ltaS double mutant suppressor strain. Taken together, these data point toward an important function of LTA in cell wall integrity through its necessity for proper peptidoglycan assembly

FOOD HABITS OF THE MAGELLANIC HORNED OWL (BUBO MAGELLANICUS) IN A COASTAL ISLAND OF PATAGONIA, ARGENTINA

Abstract ∙ The Magellanic Horned Owl (Bubo magellanicus) is one of the most common nocturnal raptors in Patagonia. The aim of this note was to analyze the food habits of this species in a small island from the Patagonian Atlantic coast. Four nesting areas and eight adults of Bubo magellanicus were found; 217 pellets plus disaggregated material were collected. We identified 2774 individual prey items. Insects were the most consumed prey (63.56%), followed by reptiles (13.73%), arachnids (10.92%), mammals (10.42%), and birds (1.37%). Our study show B. magellanicus feeding mainly on arthropods and introduced species, a fact that was not previously reported for this species in Patagonia. Resumen ∙ Hábitos alimenticios del Tucúquere (Bubo magellanicus) en una isla de Patagonia, Argentina El Tucúquere (Bubo magellanicus) es una de las rapaces nocturnas más comunes de la Patagonia. El objetivo de esta nota fue analizar los hábitos alimenticios de esta especie en una pequeña isla de la costa atlántica de la Patagonia. Se encontraron cuatro áreas de nidificación y ocho adultos de Bubo magellanicus y se recolectaron 217 egagrópilas además de material disgregado. Identificamos 2774 individuos presa. Los insectos fueron la presa más consumida (63,56%), seguidos por los reptiles (13,73%), los arácnidos (10,92%), los mamíferos (10,42%) y las aves (1,37%). La relevancia de este estudio reside en que B. magellanicus se alimenta principalmente de artrópodos y especies introducidas, hecho que no se había reportado previamente para esta especie en la Patagonia.

A Novel Mathematical Approach for Analysis of Integrated Cell–Patient Data Uncovers a 6-Gene Signature Linked to Endocrine Therapy Resistance

A significant number of breast cancers develop resistance to hormone therapy. This progression, while posing a major clinical challenge, is difficult to predict. Despite important contributions made by cell models and clinical studies to tackle this problem, both present limitations when taken individually. Experiments with cell models are highly reproducible but do not reflect the indubitable heterogeneous landscape of breast cancer. On the other hand, clinical studies account for this complexity but introduce uncontrolled noise due to external factors. Here, we propose a new approach for biomarker discovery that is based on a combined analysis of sequencing data from controlled MCF7 cell experiments and heterogeneous clinical samples that include clinical and sequencing information from The Cancer Genome Atlas. Using data from differential gene expression analysis and a Bayesian logistic regression model coupled with an original simulated annealing-type algorithm, we discovered a novel 6-gene signature for stratifying patient response to hormone therapy. The experimental observations and computational analysis built on independent cohorts indicated the superior predictive performance of this gene set over previously known signatures of similar scope. Together, these findings revealed a new gene signature to identify patients with breast cancer with an increased risk of developing resistance to endocrine therapy

Enhanced selective metal adsorption on optimised agroforestry waste mixtures

The aim of this work is to ascertain the potentials of different agroforestry wastes to be used as biosorbents in the removal of a mixture of heavy metals. Fern (FE), rice husk (RI) and oak leaves (OA) presented the best removal percentages for Cu(II) and Ni(II), Mn(II) and Zn(II) and Cr(VI), respectively. The performance of a mixture of these three biosorbents was evaluated, and an improvement of 10% in the overall removal was obtained (19.25 mg/g). The optimum mixture proportions were determined using simplexcentroid mixture design method (FE:OA:RI = 50:13.7:36.3). The adsorption kinetics and isotherms of the optimised mixture were fit by the pseudo-first order kinetic model and Langmuir isotherm. The adsorption mechanism was studied, and the effects of the carboxylic, hydroxyl and phenolic groups on metal–biomass binding were demonstrated. Finally, the recoveries of the metals using biomass were investigated, and cationic metal recoveries of 100% were achieved when acidic solutions were used.This work has been funded by the Spanish Ministry of Economy and Competitiveness, Xunta de Galicia and ERDF Funds (Projects CTM 2011-25389 and GRC 2013/003). The authors are grateful to Xunta de Galicia for financial support of the researcher Emilio Rosales under a postdoctoral Grant and the Spanish Ministry of Economy and Competitiveness for financial support of the researcher Marta Pazos under a Ramon y Cajal Grant