228 research outputs found
The Influence of Large-Scale Airborne Particle Decline and Traffic-Related Exposure on Children’s Lung Function
Between 1991 and 2000, ambient air pollution in East Germany changed to resemble West German pollution levels: The concentration of total suspended particles (TSPs) decreased on a broad scale while traffic increased. During that time, we analyzed total lung capacity (TLC) and airway resistance (R(aw)) of East and West German children. We tested children 5–7 years of age (n = 2,574) with cooperation-independent body plethysmography in repeated cross sections. We used random-effect models to determine the mutually adjusted association between lung function and short-term and chronic particle exposure and its interaction with living near a busy road. Annual averages of TSPs declined from 77 to 44 μg/m(3); averages on the day of investigation declined from 133 to 30 μg/m(3). Differences in lung function between East and West German children vanished during the investigation time. The association of TSPs with R(aw) and TLC was stronger in children living > 50 m away from busy roads. East German children from this group had an R(aw) 2.5% higher [95% confidence interval (CI), 0.0–5.1%] per 40-μg/m(3) increase of daily TSP averages. TLC decreased by 6.2% (95% CI, 0.04–11.6%) per 40-μg/m(3) increase in annual mean TSPs, and this effect was equally pronounced in East and West Germany. TSP exposure decreased on a broad scale between 1991 and 2000. Lower concentrations of TSPs were associated with better measures of lung function in 6-year-old children. For children living near busy roads, this effect was diminished
Разработка процесса сварки алюминиевых сплавов дугой переменного тока в динамическом режиме
Объектом исследования является: процесс сварки дугой, горящей на переменном токе в динамическом режиме.
Цель работы – разработка процесса сварки дугой, горящей на переменном токе в динамическом режиме.
Проводился анализ специфики сварки сплавов на основе алюминия. По результатам анализа были выделены ряд проблем процесса сварки. Был разработан процесс сварки дугой, горящей на переменном токе в динамическом режиме. А так же была разработана установка с импульсным источником питания для данного процесса сварки.The object of the research is the process of welding with arc burning on the alternative current in the dynamic mode.
The aim of the research is the process elaboration of welding with arc burning on the alternative current in the dynamic mode.
The analysis of specificity of welding of alloys based on aluminum is conducted. Based on the results of this analysis a number of problems of the welding process are discovered. The process elaboration of welding with arc burning on the alternative current in the dynamic mode is developed. Also the plant with switched mode power supply for the welding process is designed
Discovery limits for a new contact interaction at future hadronic colliders with polarized beams
The production of high-transverse energy jets in hadron-hadroncollisions is
sensitive to the presence of new contact interactions between quarks. If proton
polarization were available, the measurement of some parity violating spin
asymmetries in one-jet production at large transverse energy would complement
the usual search for deviations from the expected QCD cross section. In the
same time, a unique information on the chirality structure of the new
interaction could be obtained. In this context, we compare the potentialities
of various and colliders that are planned or have been proposed,
with the additional requirement of beam polarization.Comment: Latex file, 9 pages and 1 ps fig, definition of the subprocess
variables and one example of the effect of new contact terms on the parity
violating spin asymmetry are added. Eq. 8 (now eq. 9) and the following
equation are changed, giving better bounds in the polarized pp case (new
figure
Changes in social inequality with respect to health-related living conditions of 6-year-old children in East Germany after re-unification
BACKGROUND: Since Germany re-unified in 1990, substantial social and economic changes have happened in East Germany, the former socialist German Democratic Republic (GDR). The aim of this study was to investigate the influence of these socio-economic changes in East Germany on the association between social status, measured by parental educational level, and health-related living conditions of children during the ten-year period after re-unification. METHODS: In total, 25,864 6-year-old school beginner children (51.2% male and 48.8% female) participated in cross-sectional studies which have been repeated every year from 1991 to 2000 in East Germany. Parental educational level as a social indicator was the independent variable. Dependent variables included not employed parents, small living space and health-related living conditions (e. g. damp housing, single oven heating and living at busy road). The relationships were described by odds ratios using logistic regression. RESULTS: A large overall effect of parental educational level on health-related living conditions was observed. The time trends showed that the situation regarding small living space, damp housing conditions and single oven heating improved from 1991 to 2000, while regarding not employed parents (1996–2000) and living at busy road (1991–2000) did not, but even deteriorated. 6-year old children with low parental educational level, who lived at the time of re-unification, were often under damp housing conditions and with single oven heating at homes. Nevertheless, this social inequality has almost vanished ten years later. In contrast, we found an increasing gap between low and high parental educational level with respect to the proportion of parents who were not employed (22%: 4% gain), or lived under cramped housing conditions (22%: 37% reduction), or close to a busy road (7% gain: 2% reduction). CONCLUSION: The social inequalities which already existed under the socialist system in East Germany persisted in the system of social market economy between 1991 and 2000. 6-year-old children from families with the lowest social status were living under the worst domestic conditions (e. g. living at busy road, having damp housing conditions, single oven heating and small living space) and for some conditions (e. g. living at busy road and having small living space) the gap betweenlow and high social status was even bigger in 2000 than in 1991
High STEAP1 expression is associated with improved outcome of Ewing's sarcoma patients
Background Ewing's sarcoma (ES) is the second most common bone or soft-tissue sarcoma in childhood and adolescence and features a high propensity to metastasize. The six-transmembrane epithelial antigen of the prostate 1 (STEAP1) is a membrane-bound mesenchymal stem cell marker highly expressed in ES. Here, we investigated the role of STEAP1 as an immunohistological marker for outcome prediction in patients with ES. Patients and methods Membranous STEAP1 immunoreactivity was analyzed using immunohistochemistry in 114 primary pre-chemotherapy ES of patients diagnosed from 1983 to 2010 and compared with clinical parameters and patient outcome. Median follow-up was 3.85 years (range 0.43-17.51). Results A total of 62.3% of the ES samples displayed detectable STEAP1 expression with predominant localization of the protein at the plasma membrane. High membranous STEAP1 immunoreactivity was found in 53.5%, which correlated with better overall survival (P=0.021). Accordingly, no or low membranous STEAP1 expression was identified as an independent risk factor in multivariate analysis (hazard ratio 2.65, P=0.036). Conclusion High membranous STEAP1 expression predicts improved outcome and may help to define a specific subgroup of ES patients, who might benefit from adapted therapy regimen
Preschool children's health and its association with parental education and individual living conditions in East and West Germany
BACKGROUND: Social inequalities in health exist globally and are a major public health concern. This study focus on a systematic investigation into the associations between health indicators, living conditions and parental educational level as indicator of the social status of 6-year-old children living in West and East Germany in the decade after re-unification. Explanations of observed associations between parental education and health indicators were examined. METHODS: All boys and girls entering elementary school and living in predefined areas of East and West Germany were invited to participate in a series of cross-sectional surveys conducted between 1991 and 2000. Data of 28,888 German children with information on parental education were included in the analysis. Information about educational level of the parents, individual living conditions, symptoms and diagnoses of infectious diseases and allergies were taken from questionnaire. At the day of investigation, atopic eczema was diagnosed by dermatologists, blood was taken for the determination of allergen-specific immuno-globulin E, height and weight was measured and lung function tests were done in subgroups. Regression analysis was applied to investigate the associations between the health indicators and parental educational level as well as the child's living conditions. Gender, urban/rural residency and year of survey were used to control for confounding. RESULTS: Average response was 83% in East Germany and 71% in West Germany. Strong associations between health indicators and parental education were observed. Higher educated parents reported more diagnoses and symptoms than less educated. Children of higher educated parents were also more often sensitized against grass pollen or house dust mites, but had higher birth weights, lower airway resistance and were less overweight at the age of six. Furthermore, most of the health indicators were significantly associated with one or more living conditions such as living as a single child, unfavourable indoor air, damp housing condition, maternal smoking during pregnancy or living near a busy road. The total lung capacity and the prevalence of an atopic eczema at the day of investigation were the only health indicators those did not show associations with any of the predictor variables. CONCLUSION: Despite large differences in living conditions and evidence that some poor health outcomes were directly associated with poor living conditions, only few indicators demonstrated poorer health in social disadvantaged children. These were in both parts of Germany increased levels of overweight, higher airway resistance and, in East Germany only, reduced height in children with lower educated parents compared to those of higher education. In both East and West Germany, higher prevalence of airway symptoms was associated with a damp housing condition, and lower birth weight, reduced height and increased airway resistance at the age of six were associated with maternal smoking during pregnancy. The latter explained to a large extent the difference in birth weight and airway resistance between the educational groups
Supersymmetry breaking in two dimensions: the lattice N=1 Wess-Zumino model
We study dynamical supersymmetry breaking by non perturbative lattice
techniques in a class of two-dimensional N=1 Wess-Zumino models. We work in the
Hamiltonian formalism and analyze the phase diagram by analytical
strong-coupling expansions and explicit numerical simulations with Green
Function Monte Carlo methods.Comment: 53 pages, 17 figures, revtex
Hard diffraction in hadron--hadron interactions and in photoproduction
Hard single diffractive processes are studied within the framework of the
triple--Pomeron approximation. Using a Pomeron structure function motivated by
Regge--theory we obtain parton distribution functions which do not obey
momentum sum rule. Based on Regge-- factorization cross sections for hard
diffraction are calculated. Furthermore, the model is applied to hard
diffractive particle production in photoproduction and in
interactions.Comment: 13 pages, Latex, 13 uuencoded figure
Multiple Interactions and the Structure of Beam Remnants
Recent experimental data have established some of the basic features of
multiple interactions in hadron-hadron collisions. The emphasis is therefore
now shifting, to one of exploring more detailed aspects. Starting from a brief
review of the current situation, a next-generation model is developed, wherein
a detailed account is given of correlated flavour, colour, longitudinal and
transverse momentum distributions, encompassing both the partons initiating
perturbative interactions and the partons left in the beam remnants. Some of
the main features are illustrated for the Tevatron and the LHC.Comment: 69pp, 33 figure
Recommended from our members
The Hadronic Models for Cosmic Ray Physics: the FLUKA Code Solutions
FLUKA is a general purpose Monte Carlo transport and interaction code used for fundamental physics and for a wide range of applications. These include Cosmic Ray Physics (muons, neutrinos, EAS, underground physics), both for basic research and applied studies in space and atmospheric flight dosimetry and radiation damage. A review of the hadronic models available in FLUKA and relevant for the description of cosmic ray air showers is presented in this paper. Recent updates concerning these models are discussed. The FLUKA capabilities in the simulation of the formation and propagation of EM and hadronic showers in the Earth's atmosphere are shown
- …