On the Absorption of X-rays in the Interstellar Medium

We present an improved model for the absorption of X-rays in the ISM intended for use with data from future X-ray missions with larger effective areas and increased energy resolution such as Chandra and XMM, in the energy range above 100eV. Compared to previous work, our formalism includes recent updates to the photoionization cross section and revised abundances of the interstellar medium, as well as a treatment of interstellar grains and the H2molecule. We review the theoretical and observational motivations behind these updates and provide a subroutine for the X-ray spectral analysis program XSPEC that incorporates our model.Comment: ApJ, in press, for associated software see http://astro.uni-tuebingen.de/nh

A NLTE line blanketed model of a solar type star

We present LTE and NLTE atmospheric models of a star with solar parameters, and study the effect of treating many thousands of Iron group lines out of LTE on the computed atmospheric structure, overall absolute flux distribution, and the moderately high resolution spectrum in the visible and near UV bands. Our NLTE modeling includes the first two or three ionization stages of 20 chemical elements, up to and including much of the Fe-group, and includes about 20000 Fe I and II lines. We investigate separately the effects of treating the light metals and the Fe-group elements in NLTE. Our main conclusions are that 1) NLTE line blanketed models with direct multi-level NLTE for many actual transitions gives qualitatively similar results as the more approximate treatment of Anderson (1989) for both the Fe statistical equilibrium and the atmospheric temperature structure, 2) models with many Fe lines in NLTE have a temperature structure that agrees more closely with LTE semi-empirical models based on center-to-limb variation and a wide variety of spectra lines, whereas LTE models agree more with semi-empirical models based only on an LTE calculation of the Fe I excitation equilibrium, 3) the NLTE effects of Fe-group elements on the model structure and flux distribution are much more important than the NLTE effects of all the light metals combined, and serve to substantially increases the violet and near UV flux level as a result of NLTE Fe over-ionization. These results suggest that there may still be important UV opacity missing from the models.Comment: Accepted for publication in The Astrophysical Journa

КОМП’ЮТЕРНО-ІНФОРМАЦІЙНИЙ МОНІТОРИНГ ЗАХВОРЮВАНОСТІ НА ТУБЕРКУЛЬОЗ ПРИ ВІДНОСНІЙ СТАБІЛІЗАЦІЇ ЕПІДЕМІЇ

Ґрунтуючись на цифрових комп’ютерно-інформаційних технологіях спостереження, проведено вибіркову оцінку захворюваності на туберкульоз у різних вікових категоріях населення. З цією метою використані щорічні форми звітних матеріалів, передбачених МОЗ України, результати власних спостережень і дані банківського накопичення інформації в системі “MS EXCEL”. Вихідні позиції формувалися з врахуванням епідпоказників по Україні та Львівській області за десятирічний період спостереження (2000–2009 рр.), який у зв’язку з різними висхідними характеристиками був розділений на перший етап (2000–2004 рр.), що засвідчував прогресуюче погіршення епідситуації з туберкульозу, та другий етап (2005–2009 рр.), при якому констатували відносну стабілізацію захворюваності. Результати опрацювали з використанням статистичних і математичних функцій програми “MS EXCEL”, параметричних і непараметричних характеристик для встановлення кореляційного зв’язку при оцінці динаміки епідеміологічних показників. Отримані дані досліджень серед загальної популяції населення дозволили стверджувати, що за рівнем середній показник захворюваності на туберкульоз в Україні значно перевищував такий у Львівській області незалежно від вікового цензу населення. Разом з тим, захворюваність у вогнищах туберкульозної інфекції свідчила про зростання даного показника у Львівській області як у дитячому, підлітковому віці, так і в дорослих, що обґрунтовувало більш якісну реалізацію лікувально-профілактичних заходів.

The impact of non-LTE effects and granulation inhomogeneities on the derived iron and oxygen abundances in metal-poor halo stars

This paper presents the results of a detailed theoretical investigation of the impact of non-LTE effects and of granulation inhomogeneities on the derived iron and oxygen abundances in the metal-poor halo subgiant HD140283. Our analysis is based on both the `classical' one-dimensional (1D) stellar atmosphere models and on the new generation of three-dimensional (3D) hydrodynamical models. We find that the non-LTE effects on the iron abundance derived from Fe {\sc i} lines are very important, amounting to ${\sim}0.9$ dex and to ${\sim}0.6$ dex in the 3D and 1D cases, respectively. On the other hand, we find that non-LTE and 3D effects have to be taken into account for a reliable determination of the iron abundance from weak Fe {\sc ii} lines, because the significant overexcitation of their upper levels in the granular regions tend to produce emission features. As a result such Fe {\sc ii} lines are weaker than in LTE and the abundance correction amounts to ${\sim}0.4$ dex for the 3D case. We derive also the oxygen-to-iron abundance ratio in the metal-poor star HD140283 by using the O {\sc i} triplet at 7772--5 \AA and the forbidden [O {\sc i}] line at 6300 \AA. Interestingly, when both non-LTE and 3D effects are taken into account there still remains significant discrepancies in the iron abundances derived from Fe {\sc i} and Fe {\sc ii} lines, as well as in the oxygen abundances inferred from the O {\sc i} and [O {\sc i}] lines. We conclude that the metalicity of this type of metal-poor stars could be significantly larger than previously thought, which may have far-reaching implications in stellar astrophysics.Comment: The Astrophysical Journal (in press). (35 pages, 5 figures and 4 tables

Permitted Oxygen Abundances and the Temperature Scale of Metal-Poor Turn-Off Stars

We use high quality VLT/UVES published data of the permitted OI triplet and FeII lines to determine oxygen and iron abundances in unevolved (dwarfs, turn-off, subgiants) metal-poor halo stars. The calculations have been performed both in LTE and NLTE, employing effective temperatures obtained with the new infrared flux method (IRFM) temperature scale by Ramirez & Melendez, and surface gravities from Hipparcos parallaxes and theoretical isochrones. A new list of accurate transition probabilities for FeII lines, tied to the absolute scale defined by laboratory measurements, has been used. We find a plateau in the oxygen-to-iron ratio over more than two orders of magnitude in iron abundance (-3.2 < [Fe/H] < -0.7), with a mean [O/Fe] = 0.5 dex (sigma = 0.1 dex), independent of metallicity, temperature and surface gravity. According to the new IRFM Teff scale, the temperatures of turn-off halo stars strongly depend on metallicity, a result that is in excellent qualitative and quantitative agreement with stellar evolution calculations, which predict that the Teff of the turn-off at [Fe/H] = -3 is about 600-700 K higher than that at [Fe/H] = -1.Comment: In press, Ap

Oxygen in the Very Early Galaxy

Oxygen abundances in a sample of ultra-metal-poor subdwarfs have been derived from measurements of the oxygen triplet at 7771--5 A and OH lines in the near UV performed in high-resolution and high signal-to-noise spectra obtained with WHT/UES, KeckI/HIRES, and VLT/UVES. Our Fe abundances were derived in LTE and then corrected for NLTE effects following Thevenin and Idiart (1999). The new oxygen abundances confirm previous findings for a progressive linear rise in the oxygen-to-iron ratio with a slope -0.33+-0.02 from solar metallicity to [Fe/H] -3. A slightly higher slope would be obtained if the Fe NLTE corrections were not considered. Below [Fe/H]= -2.5 our stars show [O/Fe] ratios as high as ~ 1.17 (G64-12), which can be interpreted as evidence for oxygen overproduction in the very early epoch of the formation of the halo, possibly associated with supernova events with very massive progenitor stars. We show that the arguments against this linear trend given by Fulbright and Kraft (1999), based on the LTE Fe analysis of two metal-poor stars cannot be sustained when an NLTE analysis is performed. Using 1-D models our analysis of three oxygen indicators available for BD +23 3130 gives consistent abundances within 0.16 dex and average [O/Fe] ratio of 0.91.Comment: 45 pages, 11 figures, accepted for publication in The Astrophysical Journa

Differences sustained between diffuse and limited forms of juvenile systemic sclerosis in expanded international cohort. www.juvenile-scleroderma.com

OBJECTIVES: To evaluate the baseline clinical characteristics of juvenile systemic sclerosis (jSSc) patients in the international Juvenile SSc Inception Cohort (jSScC), compare these characteristics between the classically defined diffuse (dcjSSc) and limited cutaneous (lcjSSc) subtypes, and among those with overlap features. METHODS: A cross-sectional study was performed using baseline visit data. Demographic, organ system evaluation, treatment, and patient and physician reported outcomes were extracted and summary statistics applied. Comparisons between dcjSSc and lcSSc subtypes and patients with and without overlap features were performed using Chi-square and Mann Whitney U-tests. RESULTS: At data extraction 150 jSSc patients were enrolled across 42 centers, 83% were Caucasian, 80% female, dcjSSc predominated (72%), and 17% of the cohort had overlap features. Significant differences were found between dcjSSc and lcjSSc regarding the modified Rodnan Skin Score, presence of Gottron's papules, digital tip ulceration, 6 Minute walk test, composite pulmonary and cardiac involvement. All more frequent in dcSSc except for cardiac involvement. DcjSSc patients had significantly worse scores for physician rated disease activity and damage. A significantly higher occurrence of Gottron's papules, musculoskeletal involvement and composite pulmonary involvement, and significantly lower frequency of Raynaud's phenomenon, were seen in those with overlap features. CONCLUSION: Results from a large international jSSc cohort demonstrate significant differences between dcjSSc and lcjSSc patients including more globally severe disease and increased frequency of ILD in dcjSSc patients, while those with lcSSc have more frequent cardiac involvement. Those with overlap features had an unexpected higher frequency of interstitial lung disease

Современные подходы к диагностике и лечению синдрома активации макрофагов у детей с ревматическими заболеваниями

Macrophage activation syndrome (MAS) is a severe life-threatening complication presenting with hemophagocytosis, pancytopenia, coagulopathy, and liver and CNS dysfunctions. The disease belongs to a group of histiocytic disorders. The common triggers for MAS are rheumatic diseases, particularly systemic juvenile idiopathic arthritis (SJIA), infectious diseases, immunodeficiency, and medication. The paper describes the main stages of the pathogenesis of MAS and the role of hypercytokinemia. It presents the clinical picture of MAS and hemophagocytic lymphohistiocytoses. The evolution of diagnostic approaches to diagnosing MAS and related conditions, such as hereditary and secondary hemophagocytic lymphohistiocytosis, is considered. It is shown that it is important to elaborate diagnostic criteria for patients with SJIA. Main current approaches to therapy for MAS are outlined.Синдром активации макрофагалов (САМ) – тяжелое, жизнеугрожаемое состояние, проявляющееся гемофагоцитозом, панцитопенией, коагулопатией, нарушением функции печени и ЦНС. Заболевание относится к группе гистиоцитарных расстройств. Основными триггерными факторами САМ являются ревматические заболевания, особенно системная форма ювенильного идиопатического артрита, инфекционные заболевания, иммунодефицит, лекарственные препараты. Описаны основные этапы патогенеза САМ, роль гиперцитокинемии. Представлена клиническая картина САМ и гемофагоцитарных лимфогистиоцитозов. Рассмотрена эволюция диагностических подходов при САМ и родственных состояниях, таких как наследственный и вторичный гемофагоцитарный лимфогистиоцитоз. Показано значение разработки диагностических критериев САМ у пациентов с системной формой ювенильного идиопатического артрита. Изложены современные подходы к терапии САМ