A new method to calibrate ionospheric pulse dispersion for UHE cosmic ray and neutrino detection using the Lunar Cherenkov technique

UHE particle detection using the lunar Cherenkov technique aims to detect nanosecond pulses of Cherenkov emission which are produced during UHE cosmic ray and neutrino interactions in the Moon's regolith. These pulses will reach Earth-based telescopes dispersed, and therefore reduced in amplitude, due to their propagation through the Earth's ionosphere. To maximise the received signal to noise ratio and subsequent chances of pulse detection, ionospheric dispersion must therefore be corrected, and since the high time resolution would require excessive data storage this correction must be made in real time. This requires an accurate knowledge of the dispersion characteristic which is parameterised by the instantaneous Total Electron Content (TEC) of the ionosphere. A new method to calibrate the dispersive effect of the ionosphere on lunar Cherenkov pulses has been developed for the LUNASKA lunar Cherenkov experiments. This method exploits radial symmetries in the distribution of the Moon's polarised emission to make Faraday rotation measurements in the visibility domain of synthesis array data (i. e. instantaneously). Faraday rotation measurements are then combined with geomagnetic field models to estimate the ionospheric TEC. This method of ionospheric calibration is particularly attractive for the lunar Cherenkov technique as it may be used in real time to estimate the ionospheric TEC along a line-of-sight to the Moon and using the same radio telescope.Comment: 4 pages, 2 figures, Proceedings of ARENA 2010, Nantes, France; doi:10.1016/j.nima.2010.10.12

Kinetic hindrance during the initial oxidation of Pd(100) at ambient pressures

The oxidation of the Pd(100) surface at oxygen pressures in the 10^-6 to 10^3 mbar range and temperatures up to 1000 K has been studied in-situ by surface x-ray diffraction (SXRD). The results provide direct structural information on the phases present in the surface region and on the kinetics of the oxide formation. Depending on the (T,p) environmental conditions we either observe a thin sqrt(5) x sqrt(5) R27 surface oxide or the growth of a rough, poorly ordered bulk oxide film of PdO predominantly with (001) orientation. By either comparison to the surface phase diagram from first-principles atomistic thermodynamics or by explicit time-resolved measurements we identify a strong kinetic hindrance to the bulk oxide formation even at temperatures as high as 675 K.Comment: 4 pages including 4 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Stemness factor Sall4 is required for DNA damage response in embryonic stem cells.

Mouse embryonic stem cells (ESCs) are genetically more stable than somatic cells, thereby preventing the passage of genomic abnormalities to their derivatives including germ cells. The underlying mechanisms, however, remain largely unclear. In this paper, we show that the stemness factor Sall4 is required for activating the critical Ataxia Telangiectasia Mutated (ATM)-dependent cellular responses to DNA double-stranded breaks (DSBs) in mouse ESCs and confer their resistance to DSB-induced cytotoxicity. Sall4 is rapidly mobilized to the sites of DSBs after DNA damage. Furthermore, Sall4 interacts with Rad50 and stabilizes the Mre11-Rad50-Nbs1 complex for the efficient recruitment and activation of ATM. Sall4 also interacts with Baf60a, a member of the SWI/SNF (switch/sucrose nonfermentable) ATP-dependent chromatin-remodeling complex, which is responsible for recruiting Sall4 to the site of DNA DSB damage. Our findings provide novel mechanisms to coordinate stemness of ESCs with DNA damage response, ensuring genomic stability during the expansion of ESCs

The clinical significance of urinary tract infection and Asymptomatic Bacteriuria in Type 2 Diabetes Mellitus patients in the general practices of Varna region - Bulgaria

Background: The urinary system of diabetics is one of their most frequently affected body systems. Periodic urine analysis reveals that asymptomatic bacteriuria is very often detected in this population. Objectives: The aim of the study is to estimate the clinical significance of upper urinary tract infection (UUT/) and asymptomatic bacteriuria (ABU) in diabetics in a general practice setting, their clinical characteristics, incidence, course, evolution and complications. Methods: We tested 560 patients with type 2 diabetes mellitus (DM) from 12 general practices ofVarna region, Bulgaria in a prospective study. We traced ABU in the group for 2 years. There were 310 female patients (55.4%) mean age 52.5 ± 3.2 years and duration of DM was 8.5 ± 2.8 years. Results: The results showed that in 11.14% ABU was significant. Only 4.82% of diabetics developed upper urinary tract infection and the complications from it were very rare: 0.89% pyonephrosis and 0.89% sepsis. Conclusions: Our conclusion was that upper urinary tract infection in diabetics was not as severe as reported in the literature. Pyelonephritis had a benign course and only 16.6% of our patients developed chronic renal failure a few years later but the reason for its development was not diabetic nephropathy. All these facts show that ABU disappears spontaneously in most diabetics. Relevance to general practice: We discuss the question: is it necessary for every case of ABU in diabetics in general practice to be treated and isn't it time to revaluate the postulated antibiotic treatment for diabetics with ABU?peer-reviewe

Mapping of health technology assessment in selected countries

Objectives: The aim of this study was to develop and apply an instrument to map the level of health technology assessment (HTA) development at country level in selected countries. We examined middle-income countries (Argentina, Brazil, India, Indonesia, Malaysia, Mexico, and Russia) and countries well-known for their comprehensive HTA programs (Australia, Canada, and United Kingdom). Methods: A review of relevant key documents regarding the HTA process was performed to develop the instrument which was then reviewed by selected HTAi members and revised. We identified and collected relevant information to map the level of HTA in the selected countries. This was supplemented by information from a structured survey among HTA experts in the selected countries (response rate: 65/385). Results: Mapping of HTA in a country can be done by focusing on the level of institutionalization and the HTA process (identification, priority setting, assessment, appraisal, reporting, dissemination, and implementation in policy and practice). Although HTA is most advanced in industrialized countries, there is a growing community in middle-income countries that uses HTA. For example, Brazil is rapidly developing effective HTA programs. India and Russia are at the very beginning of introducing HTA. The other middle-income countries show intermediate levels of HTA development compared with the reference countries. Conclusions: This study presents a set of indicators for documenting the current level and trends in HTA at country level. The findings can be used as a baseline measurement for future monitoring and evaluation. This will allow a variety of stakeholders to assess the development of HTA in their country, help inform strategies, and justify expenditure for HTA

VIRTUAL LIBRARY OF THE MEDICAL UNIVERSITY OF VARNA - IDEOGENESIS, PRESENCE, AND FUTURE

The Library and Information Service at Prof. Paraskev Stoyanov Medical University of Varna has passed through several stages in its historical development. They results obtained are related with the timely recognition of the necessity of introduction in the Library of the new information technologies. Thus the library staff faces the requirements of the information society of the new millennium. The enthusiastic efforts of the governing body of the library are directed to the permanent improvement of information retrieval in the university medical libraries in Bulgaria, the coordination of their computerization, and the creative enrichment of the forms and methods of information service of the teachers and students. Modern audiovisual means are used along with interactive user's education for independent search in the foreign databases in the library and through Internet. The electronic-mail connections help delivering the documents to the readers in the university departments and clinics after scanning the paper information sources in our library and in other libraries. The electronic library catalogue of books is already accessible through Internet. Our idea of a modern virtual library opened to the future and preserving the rich traditions of our University becomes step-by-step a fascinating reality

KALLIKREIN-KININ SYSTEM (KKS) AND ANGIOTENSIN CONVERTING ENZYME ACTIVITY (ACE) IN PATIENTS ON PERIODIC HA•MODIALYSIS (PHD) TREATED WITH RECOMBINANT HUMAN ERYTHROPOIETIN (rhEPO)

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