A spiral structure in the disk of EX Draconis on the rise to outburst maximum

We report on the R-band eclipse mapping analysis of high-speed photometry of the dwarf nova EX Dra on the rise to the maximum of the November 1995 outburst. The eclipse map shows a one-armed spiral structure of ~180 degrees in azimuth, extending in radius from R ~0.2 to 0.43 R_{L1} (where R_{L1} is the distance from the disk center to the inner Lagrangian point), that contributes about 22 per cent of the total flux of the eclipse map. The spiral structure is stationary in a reference frame co-rotating with the binary and is stable for a timescale of at least 5 binary orbits. The comparison of the eclipse maps on the rise and in quiescence suggests that the outbursts of EX Dra may be driven by episodes of enhanced mass-transfer from the secondary star. Possible explanations for the nature of the spiral structure are discussed.Comment: To appear in the Astrophysical Journal Letters; 8 pages, 2 figures; coded with AAS latex styl

Atypical Presentations of Hearing Loss in Patients with Acoustic Neuroma

A hipoacúsia neurosensorial unilateral e progressiva é uma das principais manisfestações audiológicas dos doentes com diagnóstico de neurinoma do acústico, estando no entanto descritas outras formas de apresentação. Dos 43 doentes com diagnóstico de neurinoma do acústico, tratados pela equipa de otoneurocirurgia entre 1997 e 2003, identificamos 88,5% com hipoacústica neurosensorial unilateral, 4,6% como hipoacústica neurosensorial súbita, 4,6% com audição simétrica e 2,3% com audição "normal". Estes dados revelam a existência de três formas incomuns de apresentação dos neurinomas, facto que deve levar os otorrinolaringologistas a manterem um elevado grau de alerta perante doentes com queixas que possam sugerir, de algum modo, a presença de neurinoma do acústico

Renal Artery Angioplasty

Efectuámos angioplastia transiuminal percutânea (ATP) da artéria renal em 59 doentes hipertensos e houve benefício inicial na tensão arterial em 91,5% e tardio em 79,6%. Obtivemos melhores resultados nas lesões unilaterais (81,4%) do que nas bilaterais (72,7%); nas lesões fora do ostium (82,5%) do que nas do ostium (7 1,4%); nas lesões de origem fibromuscular (88,9%) do que nas de origem aterosclerótica(75%); e nos doentes com idade igual ou inferior a 55 anos (84,8%) do que em doentes com idade superior (71,4%). Estas diferenças não foram contudo significativas. Os bons resultados da ATP da artéria renal na hipertensão renovascular levam-nos a considerar esta forma de intervenção como uma alternativa do seu tratamento

Mean pulmonary arterial pressure after percutaneous mitral valvuloplasty predicts long-term adverse outcomes

INTRODUCTION AND AIM: Percutaneous mitral valvuloplasty (PMV) is an effective treatment option for mitral stenosis (MS), but its success is assessed on the basis of clinical and echocardiographic outcomes in studies with relatively short follow-up. We aimed to characterize a cohort of patients undergoing PMV with long-term follow-up and to determine independent predictors of post-PMV mitral re-intervention and event-free survival. METHODS: We studied 91 consecutive patients with MS who underwent PMV with a median clinical follow-up duration of 99 months. Two endpoints were considered: post-PMV mitral re-intervention (PMV or mitral surgery) and a composite clinical events endpoint including cardiovascular death, mitral valve re-intervention and hospital admission due to decompensated heart failure. We compared patients who required post-PMV mitral re-intervention with those who did not during follow-up. RESULTS: The study population included 83.5% females and mean age was 48.9±13.9 years. The 1-, 3-, 5-, 7- and 9-year rates of clinical event-free survival were 93.0±2.8%, 86.0±3.9%, 81.0±4.4%, 70.6±5.6%, and 68.4±5.8%, respectively. The 1-, 3-, 5-, 7- and 9-year rates of mitral re-intervention-free survival were 98.8±1.2%, 97.5±1.7%, 92.1±3.1%, 85.5±4.5%, and 85.5±4.5%, respectively. The median time to mitral re-intervention was 6.2 years. Patients who required mitral re-intervention during follow-up were younger (43.3 vs. 51.2 years, p=0.04) and had higher pre- and post-PMV mitral gradient (14.9 vs. 11.5mmHg, p=0.02 and 6.4 vs. 2.1mmHg, p<0.001) and higher post-PMV mean pulmonary artery pressure (mPAP) (30.0 vs. 23.2mmHg, p=0.01). In a Cox proportional hazards model, mPAP ≥25mmHg was the sole predictor of both mitral re-intervention (HR 5.639 [1.246-25.528], p=0.025) and clinical events (HR 3.622 [1.070-12.260], p=0.039). CONCLUSION: In our population, immediate post-PMV mPAP was the sole predictor of post-PMV mitral intervention. These findings may help identify patients in need of closer post-PMV follow-up

Large magnetic anisotropy in Ferrihydrite nanoparticles synthesized from reverse micelles

Six-line ferrihydrite(FH) nanoparticles have been synthesized in the core of reverse micelles, used as nanoreactors to obtain average particle sizes $$ $\approx$ 2 to 4 nm. The blocking temperatures $T_B^m$ extracted from magnetization data increased from $\approx 10$ to 20 K for increasing particle size. Low-temperature \MOS measurements allowed to observe the onset of differentiated contributions from particle core and surface as the particle size increases. The magnetic properties measured in the liquid state of the original emulsion showed that the \FH phase is not present in the liquid precursor, but precipitates in the micelle cores after the free water is freeze-dried. Systematic susceptibility \chi_{ac}(\emph{f},T) measurements showed the dependence of the effective magnetic anisotropy energies $E_{a}$ with particle volume, and yielded an effective anisotropy value of $K_{eff} = 312\pm10$ kJ/m$^3$.Comment: 8 pages, 10 figures. Nanotechnology, v17 (Nov. 2006) In pres

Accretion Disc Evolution in DW Ursae Majoris: A Photometric Study

We present an analysis of CCD photometric observations of the eclipsing novalike cataclysmic variable DW UMa obtained in two different luminosity states: high and intermediate. The star presents eclipses with very different depth: ~1.2 mag in the high and ~3.4 mag in the intermediate state. Eclipse mapping reveals that this difference is almost entirely due to the changes in the accretion disc radius: from ~0.5RL1 in the intermediate state to ~0.75RL1 in the high state (RL1 is the distance from the white dwarf to the first Lagrangian point). In the intermediate state, the entire disc is eclipsed while in the high state, its outer part remains visible. We also find that the central intensity of the disc is nearly the same in the two luminosity states and that it is the increase of the disc radius that is responsible for the final rise from the 1999/2000 low state. We find that the intensity profile of the disc is rather flat and suggest a possible explanation. We also discuss the effect of using a more realistic limb-darkening law on the disc temperatures inferred from eclipse mapping experiments. Periodogram analysis of the high state data reveals "positive superhumps" with a period of 0.1455 in 2002 and 0.1461 in 2003, in accord with the results of Patterson et al. However, we cannot confirm the quasi-periodic oscillations reported by these authors. We obtain an updated orbital ephemeris of DW UMa: Tmin[HJD]=2446229.00687(9)+0.136606527(3)E.Comment: 11 pages, 8 figure

Investigation of the new cataclysmic variable 1RXS J180834.7+101041

We present the results of our photometric and spectroscopic studies of the new eclipsing cataclysmic variable star 1RXS J180834.7+101041. Its spectrum exhibits double-peaked hydrogen and helium emission lines. The Doppler maps constructed from hydrogen lines show a nonuniform distribution of emission in the disk similar to that observed in IP Peg. This suggests that the object can be a cataclysmic variable with tidal density waves in the disk. We have determined the component masses (M_WD =0.8 \pm 0.22 M_sun and M_RD =0.14 \pm 0.02 M_sun) and the binary inclination (i =78 \pm 1.5 deg) based on well-known relations between parameters for cataclysmic variable stars. We have modeled the binary light curves and showed that the model of a disk with two spots is capable of explaining the main observed features of the light curves.Comment: 22 pages, 9 figures, 2 tables, published in Astronomy Letters, 2011, 37, 845-85

Pathways to ensure universal and affordable access to hepatitis C treatment

Direct-acting antivirals (DAAs) have dramatically changed the landscape of hepatitis C treatment and prevention. The World Health Organization has called for the elimination of hepatitis C as a public health threat by 2030. However, the discrepancy in DAA prices across low-, middle- and high-income countries is considerable, ranging from less than US$100 to approximately US$ 40,000 per course, thus representing a major barrier for the scale-up of treatment and elimination. This article describes DAA pricing and pathways to accessing affordable treatment, providing case studies from Australia, Egypt and Portugal. Pathways to accessing DAAs include developing comprehensive viral hepatitis plans to facilitate price negotiations, voluntary and compulsory licenses, patent opposition, joint procurement, and personal importation schemes. While multiple factors influence the price of DAAs, a key driver is a country's capacity and willingness to negotiate with pharmaceutical companies. If negotiations do not lead to a reasonable price, governments have the option to utilise flexibilities outlined in the Agreement on Trade-Related Aspects of Intellectual Property Rights. Affordable access to DAAs is underpinned by collaboration between government, civil society, global organisations and pharmaceutical companies to ensure that all patients can access treatment. Promoting these pathways is critical for influencing policy, improving access to affordable DAAs and achieving hepatitis C elimination

Priorities for energy efficiency measures in agriculture.

This report provides a compilation of energy efficiency measures in agriculture, their opportunities and constraints to implement energy efficient agricultural systems across Europe as a result of the AGREE (Agriculture & Energy Efficiency) Coordination and Support Action funded by the 7th research framework of the EU (www.agree.aua.gr). The report dwells on earlier reports of the consortium, which listed potential energy efficiency measures (Project Deliverable 2.3: Energy Saving Measures in Agriculture – Overview on the Basis of National Reports) and identified trade-offs and win-win situations of various energy efficiency measures in agriculture (Project Deliverable 3.1: Economic and environmental analysis of energy efficiency measures in agriculture). It shows research gaps in crop production, greenhouse production, animal husbandry and system approaches, which can be regarded as priorities for energy efficiency measures in agriculture. The report is na important input for the strategic research agenda, which is one of the main outputs of the AGREE project

Vortices on Orbifolds

The Abelian and non-Abelian vortices on orbifolds are investigated based on the moduli matrix approach, which is a powerful method to deal with the BPS equation. The moduli space and the vortex collision are discussed through the moduli matrix as well as the regular space. It is also shown that a quiver structure is found in the Kahler quotient, and a half of ADHM is obtained for the vortex theory on the orbifolds as the case before orbifolding.Comment: 25 pages, 4 figures; references adde