Functional diversity of extracellular matrix components during vessel migration, endothelial sprouting and blood vessel stabilization

The formation of mature blood vessels requires recruitment of mural cells (MC) and generation of an extracellular matrix in order to stabilize and support the nascent vessel. The precise sequence of basement membrane protein expression and function during initiation, elongation and stabilization of the angiogenic sprout remains unclear. The first project describes a function of astrocytic Fibronectin (FN) in guided vessel migration. Integrin-binding is dispensable for fibrilliar FN assembly but mediates endothelial cell adhesion in vivo. VEGF-A dependent migration of retinal vessels requires PI3K activity and astrocytic FN possibly functions to retain VEGF protein on the astrocytic matrix. In a second project we discovered endothelial tip cells-specific expression of laminin alpha4 (Lama4) and provide first evidence for an influence of laminin α4 on endothelial Dll4/Notch signalling in sprouting angiogenesis. Loss of Lama4 leads to increased filopodia formation, tip cell numbers and consequently increased vessel density, resembling the phenotype of disturbed Dll4/Notch signalling. Loss of Lama4 leads to reduced Dll4 and Notch target gene expression, whereas gain-of-function results in increased Dll4 expression in vitro. Preliminary results suggest that laminin α4 induced Dll4 expression involves both VEGFR2 and integrin signalling. The third project addresses the cell-autonomous requirement of heparan sulfate (HS) production by MCs during mouse embryonic vascular development. Conditional deletion of HS synthesis in MC caused severe vascular defects and embryonic lethality. Unexpectedly, distinct regions of vascular growth showed selective requirement for MC HS production: whereas MC recruitment in peripheral skin vascularization is severely disrupted, MCs during brain angiogenesis appear unaffected. Similarly, PDGF-B and TGF-β signalling are impaired in the peripheral vessels, but not in the brain. These data suggest that cell-autonomous HS is essential for MC recruitment in the skin vasculature, where induction and differentiation of local progenitor cells from the mesenchymal cell lineage is mediated by TGF-β signalling

Cross-Border Investments in Private Firms: The Benefits of Comparability for Foreign Investors

We examine the benefits of accounting comparability for cross-border investments in private firms. Exploiting a quasi-experimental setting, we examine the effect of an increase in accounting comparability using a difference-in-differences research design. We find that increases in accounting comparability after a major accounting reform leads to an average increase in foreign ownership of about 2 to 6 percent. Cross-sectional and industry results confirm that the effect is stronger for smaller, highly profitable, intangible-intensive, and more stable firms that are in the consumer durables and manufacturing industries. The findings are robust to alternative matching procedures, various measurement windows, and a placebo-test. Our large sample evidence based on private firms provides insights on the effects of increasing the comparability of local GAAP for foreign-direct investments in private firms. Additionally, our findings are relevant to standard setters as countries converge towards and endorse International Financial Reporting Standards and update their local GAAP

QCD studies with e+e−e^+ e^- annihilation data from 130 to 172 GeV

Hadronic events produced at LEP at centre-of-mass energies of 130, 136, 161 and 172 GeV have been studied and compared with QCD predictions. Distributions of event-shape observables, jet rates, momentum spectra and multiplicities are presented and compared to the predictions of several Monte Carlo models and analytic QCD calculations. From a fit of O(alpha_s^2)+NLLA QCD calculations to the differential two-jet rate, alpha_s has been determined at various energies. The mean charged particle multiplicities and the peak positions xi_star in the xi = ln(1/x_p) distribution have also been determined. These results have been compared to lower energy data and to analytic QCD or Monte Carlo predictions for their energy evolution

On the uncertainty relations and squeezed states for the quantum mechanics on a circle

The uncertainty relations for the position and momentum of a quantum particle on a circle are identified minimized by the corresponding coherent states. The sqeezed states in the case of the circular motion are introduced and discussed in the context of the uncertainty relations.Comment: 4 figure

High-Precision Temperature Control of a Crystal Growth Furnace at 1,500 C

For crystal growth of semiconductor materials a short-term temperature stability of 0.1 C at 1500 C is one of the essential parameters to be addressed for achieving high-quality crystals. Hence, for temperature monitoring and control with high precision in a floating zone furnace two sets of thermo-sensors, type B thermocouples and optical fibre thermometers, have been implemented and successfully operated in the furnace for more than 2000 h. The optical fibre thermometers consist of an optical system made of sapphire (two fibres plus a prism in between for deflection) and transmit the infra-red radiation of the heater to the outside of the hot core of the furnace for pyrometric temperature measurement. A dedicated control algorithm has been set up which controlled the power settings to the individual heaters. Both sensor types showed no degradation after this period and yielded a short-term stability at 1200 C of 0.05 C (optical fibre thermometers), respectively 0.08 C (thermocouples)

Incidental finding of a microsporidian parasite from an AIDS patient

Light microscopic examination of feces from a human immunodeficiency virus-positive patient with chronic diarrhea, anorexia, and lethargy revealed the presence of numerous refractile bodies resembling microsporidian spores. They were subsequently identified as belonging to the genus Nosema on the basis of their ultrastructural characteristics. However, the microsporidia were enclosed within striated muscle cells, suggesting that they were probably ingested in food; thus, this represented an incidental finding rather than a true infection

Анализ эффективности использования бинарного цикла ПТУ на тепловой электростанции

Выпускная квалификационная работа 55 с., 8 рис., 7 табл., 32 источника, приложений нет. Ключевые слова: электростанция, паротурбинная установка (ПТУ), бинарный цикл, низкопотенциальное рабочее тело (НРТ), эффективность. Объектом исследования является двухконтурная ПТУ с НРТ. Цель работы – провести анализ эффективности использования бинарного цикла ПТУ на тепловой электростанции (ТЭС). В работе представлен анализ эффективности использования бинарного цикла ПТУ на ТЭС на основе расчета термического коэффициента полезного действия (КПД) двухконтурной ПТУ с НРТ. В результате исследования выявлено, что термический КПД двухконтурной ПТУ с НРТ больше термического КПД одноконтурной ПТУ на 29,5 %.Graduate qualification work 55 p., 8 pic., 7 tab., 32 references, no appendices. Keywords: power plant, steam tubine plant (STP), binary cycle, low-potential working fluid (LWF), efficiency. Object of investigation is two-curcuit STP with LWF. Work purpose - analyze the efficiency of use binary cycle STP on thermal power plant (TPP). The paper presents the analysis of the effeciency of use binary cycle STP on TPP on the basis of calculation thermal coefficient of performance (COP) two-curcuit STP with LWF. The study revealed that thermal COP two-curcuit STP with LWF more than thermal COP of one-curcuit STP at 29,5 %

Global scenarios of irrigation water abstractions for bioenergy production: a systematic review

Many scenarios of future climate evolution and its anthropogenic drivers include considerable amounts of bioenergy as a fuel source, as a negative emission technology, and for providing electricity. The associated freshwater abstractions for irrigation of dedicated biomass plantations might be substantial and therefore potentially increase water limitation and stress in affected regions; however, assumptions and quantities of water use provided in the literature vary strongly. This paper reviews existing global assessments of freshwater abstractions for bioenergy production and puts these estimates into the context of scenarios of other water-use sectors. We scanned the available literature and (out of 430 initial hits) found 16 publications (some of which include several bioenergy-water-use scenarios) with reported values on global irrigation water abstractions for biomass plantations, suggesting water withdrawals in the range of 128.4 to 9000 km3 yr−1, which would come on top of (or compete with) agricultural, industrial, and domestic water withdrawals. To provide an understanding of the origins of this large range, we present the diverse underlying assumptions, discuss major study differences, and calculate an inverse water-use efficiency (iwue), which facilitates comparison of the required freshwater amounts per produced biomass harvest. We conclude that due to the potentially high water demands and the tradeoffs that might go along with them, bioenergy should be an integral part of global assessments of freshwater demand and use. For interpreting and comparing reported estimates of possible future bioenergy water abstractions, full disclosure of parameters and assumptions is crucial. A minimum set should include the complete water balances of bioenergy production systems (including partitioning of blue and green water), bioenergy crop species and associated water-use efficiencies, rainfed and irrigated bioenergy plantation locations (including total area and meteorological conditions), and total biomass harvest amounts. In the future, a model intercomparison project with standardized parameters and scenarios would be helpful