Відлуння Чорнобиля

Свого часу одну з перших книг, у якій було зроблено спробу з’ясувати істинні причини аварії на Чорнобильський АЕС, написав міністр енергетики України В.Ф. Скляров. До 25-ї річниці Чорнобильської катастрофи цю книгу перевидано під назвою «Завтра был Чернобыль +». У новому виданні своєрідний «погляд із середини» активного учасника ліквідації наслідків аварії на ЧАЕС доповнено бесідами з керівниками і фахівцями різного профілю, що дало змогу детально і глибоко розглянути проблему Чорнобиля в контексті його минулого, сьогодення і майбутнього. Вміщуємо в перекладі на українську мову фрагменти розмови В.Ф. Склярова з президентом НАН України академіком Б.Є. Патоном

Молодь і політика: соціологічні парадокси та українські реалії

The exchange of phosphatidylcholine between intact human or rat erythrocytes and rat liver microsomes was greatly stimulated by phosphatidylcholine-specific exchange proteins from rat liver and beef liver. It was found, however, that compared to the exchange reaction between phospholipid vesicles and rat liver microsomes, much higher concentrations of exchange protein were required in the case of intact red blood cells and microsomes. In human erythrocytes, 75% of the phosphatidylcholine was available for exchange within 2 h at 37°C. No additional exchange was observed during the next 2 h, indicating slow, if any, transbilayer movement of the residual phosphatidylcholine. In rat erythrocytes 50-60% of the phosphatidylcholine was readily available for the exchange proteins. The residual phosphatidylcholine was exchanged at a much lower rate with a half time for equilibration of 7 h. These results confirm in an independent way the asymmetric distribution of phosphatidylcholine over the membrane of human and rat erythrocytes as well as the occurrence of a slow transbilayer movement of this lipid in rat erythrocytes

CO ro-vibrational lines in HD100546: A search for disc asymmetries and the role of fluorescence

We have studied the emission of CO ro-vibrational lines in the disc around the Herbig Be star HD100546 with the final goal of using these lines as a diagnostic to understand inner disc structure in the context of planet formation. High-resolution IR spectra of CO ro-vibrational emission at eight different position angles were taken with CRIRES at the VLT. From these spectra flux tables, CO ro-vibrational line profiles, and population diagrams were produced. We have investigated variations in the line profile shapes and line strengths as a function of slit position angle. We used the thermochemical disc modelling code ProDiMo based on the chemistry, radiation field, and temperature structure of a previously published model for HD100546. Comparing observations and the model, we investigated the possibility of disc asymmetries, the excitation mechanism (UV fluorescence), the geometry, and physical conditions of the inner disc. The observed CO ro-vibrational lines are largely emitted from the inner rim of the outer disc at 10-13 AU. The line shapes are similar for all v levels and line fluxes from all vibrational levels vary only within one order of magnitude. All line profile asymmetries and variations can be explained with a symmetric disc model to which a slit correction and pointing offset is applied. Because the angular size of the CO emitting region (10-13 AU) and the slit width are comparable the line profiles are very sensitive to the placing of the slit. The model reproduces the line shapes and the fluxes of the v=1-0 lines as well as the spatial extent of the CO ro-vibrational emission. It does not reproduce the observed band ratios of 0.5-0.2 with higher vibrational bands. We find that lower gas volume densities at the surface of the inner rim of the outer disc can make the fluorescence pumping more effcient and reproduce the observed band ratios.Comment: 20 pages, 21 figure

Radiation thermo-chemical models of protoplanetary discs. III. Impact of inner rims on Spectral Energy Distributions

We study the hydrostatic density structure of the inner disc rim around HerbigAe stars using the thermo-chemical hydrostatic code ProDiMo. We compare the Spectral Energy Distributions (SEDs) and images from our hydrostatic disc models to that from prescribed density structure discs. The 2D continuum radiative transfer in ProDiMo includes isotropic scattering. The dust temperature is set by the condition of radiative equilibrium. In the thermal-decoupled case the gas temperature is governed by the balance between various heating and cooling processes. The gas and dust interact thermally via photoelectrons, radiatively, and via gas accommodation on grain surfaces. As a result, the gas is much hotter than in the thermo-coupled case, where the gas and dust temperatures are equal, reaching a few thousands K in the upper disc layers and making the inner rim higher. A physically motivated density drop at the inner radius ("soft-edge") results in rounded inner rims, which appear ring-like in near-infrared images. The combination of lower gravity pull and hot gas beyond ~1 AU results in a disc atmosphere that reaches a height over radius ratio z/r of 0.1 while this ratio is 0.2 only in the thermo-coupled case. This puffed-up disc atmosphere intercepts larger amount of stellar radiation, which translates into enhanced continuum emission in the 3- 30 micron wavelength region from hotter grains at ~500 K. We also consider the effect of disc mass and grain size distribution on the SEDs self-consistently feeding those quantities back into the gas temperature, chemistry, and hydrostatic equilibrium computation.Comment: Accepted to MNRA

Muscle Quality is More Impaired in Sarcopenic Patients With Chronic Obstructive Pulmonary Disease

BACKGROUND: Quadriceps muscle fiber atrophy and a loss of oxidative type I muscle fibers and mitochondrial content often occur in chronic obstructive pulmonary disease (COPD), which adversely affects exercise performance. Sarcopenia is an age-related syndrome characterized by wasting and weakness of muscle mass. We recently showed in a large cohort of patients that COPD-related sarcopenia, in particular in male patients, was not only associated with impaired quadriceps muscle strength but also with decreased exercise performance endurance, which could imply involvement of altered muscle fiber type composition. Hence, we hypothesized that both the fiber atrophy and loss of oxidative muscle fibers are more pronounced in sarcopenic compared with nonsarcopenic patients with COPD. OBJECTIVE: The objective of this study was to investigate quadriceps muscle fiber-type characteristics in relation to presence of sarcopenia in patients with COPD and in healthy age-matched controls. DESIGN: For this retrospective cross-sectional study, body composition (assessed by dual-energy x-ray absorptiometry) and quadriceps muscle biopsy (fiber type distribution and sizes) data were collected from 45 patients with COPDs (aged 42-77 years) and 52 healthy controls (aged 50-77 years). Sarcopenia was based on assessment of appendicular skeletal muscle mass index. RESULTS: Sarcopenia was found in 5.8% of healthy controls and in 31.1% of patients with COPD (P < .01). The proportion of oxidative type I fibers and size of type IIx muscle fibers were decreased in patients with COPD, and the sarcopenic subgroup showed a further decreased proportion as well as a lower size of type I fibers. CONCLUSIONS: Type I muscle fiber proportion is lower in sarcopenic compared with nonsarcopenic patients with COPD. Longitudinal studies may elucidate if the loss of muscle oxidative phenotype drives or accelerates the process of muscle wasting

How transparent are European banks on sustainability?

De transitie naar een duurzame economie, waarbij economische, milieu- en sociale aspecten beter met elkaar in evenwicht zijn, vergt grote investeringen. De financiële dienstensector heeft een belangrijke faciliterende rol. Op Europees niveau komt daarom verdere wetgeving op het gebied van duurzame investering en financiering en de transparantie daarover. Dit onderzoek onder 50 grote Europese banken toont aan dat zij weliswaar veel pagina's besteden aan het onderwerp, maar dat onvoldoende inzicht wordt gegeven over duurzaamheid in de kernactiviteiten, te weten duurzame investering en financiering, hoe duurzaamheid strategisch is gekoppeld aan prestatie-indicatoren en beloningsbeleid en risicomanagement. Er is een goed begin gemaakt, maar er moet nog veel gebeuren