Divergence of the Stark collision operator at large impact parameters in plasma spectroscopy models.

The divergence that occurs at large impact parameters in Stark collision operators is examined for low-density hydrogen plasmas. In a previous work [J. Rosato, H. Capes, and R. Stamm, Phys. Rev. E 86, 046407 (2012)], we showed that the correlations between a radiating atom and the charged particles surrounding it affect the mean evolution of the atom, resulting in a mitigation of the Stark broadening near the line center. In this work, we examine the physical mechanism underlying this mitigation with an approach inspired from the standard semiclassical impact model. Our approach accounts for the atom-perturber correlations in a simple fashion, through a cutoff at large impact parameters, and embraces the impact model in the weakly coupled plasma limit. Comparisons with numerical simulations are performed and indicate a good agreement.

Influence of correlated collisions on Stark-broadened lines in plasmas.

An investigation of spectral line broadening in plasmas is carried out within a kinetic-theory approach, based on the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. The model employs a resummation procedure to account for correlated emitter-perturber collisions. Applications to hydrogen lines indicate that such collisions strongly affect the width and the shape in the core region. This argument is supported by comparisons to numerical simulations. It is also shown that the usual collision operator models, based on a binary description of emitter-perturber collisions, can be extremely inaccurate. The present model, in a better agreement with numerical simulations, is suggested as an extension suitable for the design of fast and accurate numerical routines for plasma diagnostics.

Stark broadening of hydrogen lines in low-density magnetized plasmas.

Stark broadening of hydrogen lines in the presence of a magnetic field is revisited, with emphasis on the role of the ion component under typical conditions of magnetized fusion devices. An impact theory for ions valid at low density (N_{e} < or approximately 10;{14} cm;{-3}) and taking into account the Zeeman degeneracy removal of the atomic states is developed. It is shown that the Stark widths of the Lorentz triplet components strongly depend on the magnetic field. The model is validated by a computer simulation method. For the lateral sigma components of Lyalpha , we show that the impact approximation still holds for densities as high as N_{e} approximately 10;{15} cm;{-3}. In contrast, for the central pi component as well as for the other lines from low principal quantum number, significant discrepancies between the proposed theory and the simulation results appear at high density. Application to Dalpha in tokamak divertor plasma conditions shows that, in this case, the quasistatic approximation becomes more relevant.

Fill-tube-induced mass perturbations on x-ray-driven, ignition-scale, inertial-confinement-fusion capsule shells and the implications for ignition experiments.

On the first inertial-confinement-fusion ignition facility, the target capsule will be DT filled through a long, narrow tube inserted into the shell. microg-scale shell perturbations Delta m' arising from multiple, 10-50 microm-diameter, hollow SiO2 tubes on x-ray-driven, ignition-scale, 1-mg capsules have been measured on a subignition device. Simulations compare well with observation, whence it is corroborated that Delta m' arises from early x-ray shadowing by the tube rather than tube mass coupling to the shell, and inferred that 10-20 microm tubes will negligibly affect fusion yield on a full-ignition facility.

Dependence of young female volleyballers' performance on their body build, physical abilities, and psycho-physiological properties.

AIM: The aim of the study was to establish which anthropometric characteristics, physical abilities and psycho-physiological properties determine the success of adolescent female volleyballers at competitions. METHODS: For this purpose we studied 32 female volleyballers aged 13-16 years. The anthropometric examination included 43 measurements, 7 tests of physical fitness, and 4 series of computerised psycho-physiological tests (n=21). The performance of game elements was measured empirically during championship games using the original computer program "Game". RESULTS: The proficiency of performing volleyball elements - serve, reception, feint, block and spike - was calculated by regression models from the 14 anthropometric measurements, 4 physical fitness and 7 psychophysiological test results, which showed significant correlation with proficiency in the game. The predictive power of the models was at least 32% and in average 56%. The anthropometric factor was significant in the performance of all the elements of the game, being most essential (71-83%) for attack, block and feint. Good results in physical ability tests granted success in serve, attack and reception. CONCLUSION: It was possible to predict the efficiency of reception (44%) by endurance, flexibility and speed measuring tests. Medicine ball throwing test was essential for attack (22%). Psycho-physiological tests were significant for the performance of block (98%), attack (80%), feint (60%) and reception (39%).

A possibility of systematisation of anthropometric data of girls aged 12-15.

The article describes an anthropometric cross-sectional study of 374 healthy schoolgirls aged 12-15 years from secondary schools of Tartu (Estonia). 29 body measurements and 9 skinfolds were measured. Mean skinfolds and 6 indices and ratios (including body mass index) were calculated. In each age group the data were systematized into 5 height-weight SD-classes according to the correspondence between body height and weight. The medium class lies between -0.5 SD and +0.5 SD of the respective age group mean (M +/- 0.5 SD); the other classes contain the respective outer values. All the subjects were assigned into one of the following five categories: three height/weight-concordant categories: I = small (small height-small weight), II = medium (medium height-medium weight), III = large (big height-big weight) and two height/weight-disconcordant categories: IV = so-called pyknomorphous, V = so-called leptomorphous. Categories IV and V thus contained three height/weight subclasses each. The body build categories differ significantly from each other within both groups (I-III and IV-V) in all age groups in all measured variables, except sternum length, abdomen length, trunk length, biacromial breadth, biiliocrystal breadth, femur breadth, ankle breadth, humerus breadth, wrist breadth, and head circumference for which no significant differences between pyknomorphous and leptomorphous categories were found. A multidimensional statistical model of body build might be used in girls going through puberty to systematize and compare morphological variables with other assessed characteristics in different applied studies, for example physiological, sociological, psychological, or nutritional.

[Concepts of vulnerability of psychiatric diseases]. / Vulnerabilitätskonzepte bei psychischen Störungen.

Despite intensive research in recent decades, the search for the aetiopathogenesis of psychiatric diseases is just as relevant as ever. In recent years, ideas of the aetiopathogenesis of psychotic diseases based on the concept of "vulnerability" in its diverse variations and developments have been gained increasingly ground. The publications of Zubin and associates above all have contributed to a "vulnerability model". According to this descriptive model, schizophrenic disturbances develop as a result of stimuli/irritants or stress factors under modulation of the social and physical environment as well as dependent on the premorbid personality. The increased vulnerability which gives rise to this is perceived as a threshold descensus of the individual towards stimuli/irritants (with a deficit counter--irritants impulses). Apart from that, multi-causality of vulnerability is assumed as the starting point, whereby there is the possibility of several therapy approaches. Moreover, contrary to the prevailing pessimistic view that schizophrenia is a process-type progressive disease, an episodic nature of schizophrenic psychoses is postulated with a prognosis that is indeed positive in the long term. In recent years, although often not explicitly stated, Zubin's concept of vulnerability was also indubitably subjected to various further developments (the vulnerability stress model by Nuechterlein and associates as also the integrative psycho-biological schizophrenia model by Ciompi may serve as examples). Worth mentioning are also various new concepts from system sciences (such as those from cybernetics, synergetics, the chaos theory, the communication theory, structure determinism etc.), which endeavour to clarify the problem of psychosis. The evaluation of central neurophysiological function deviations with schizophrenics and their relations has so far been oriented above all towards the vulnerability model of Zubin and Nuechterlein, which differentiates temporarily relatively stable trait markers with generally unaltered expressivity at the pre-, intra-, and post-psychotic stages as well as episode markers and intermediate markers. However, specific factors contributing to the pathogenesis of schizophrenic disturbances have not as yet been found, in addition, there is still a multitude of methodological problems and distinctive features to fulfill the expectation of a comprehensive concept with which the whole complexity of the occurrence, the progress, and the outcome of psychoses can be explained. Reintroduction of the concept of vulnerability experienced, as Schmidt-Degenhardt put it, "a renaissance in use that appeared almost inflationary and a completely dubious popularisation ... without reference to its historical implications...". Consequently, a critical view of the use of this term would appear to be necessary.

MEGA-database: one million data since 1972.

MEGA is the chemical workplace exposure database of the Institute for Occupational Safety (BIA) of the German Berufsgenossenschaften (BG) (statutory accident institutions for insurance and prevention). On the legal basis of the social insurance law the inspectorates of the BGs conduct workplace measurements of chemical and biological agents. The BGs have cooperated with BIA within the Berufsgenossenschaftliches Messsystem Gefahrstoffe--BGMG since 1972: measurements are done by the BGs, analyses and data processing are the tasks of BIA. In 1999 31,000 measurements with 68,000 analyses were taken in 4,000 enterprises. All data are stored in the MEGA-database with up to 150 pieces of information (describing type of workplace, working conditions, measured substances, sampling strategy, sampling duration, sampling and analytical method etc.), for each result. MEGA contains today about 1,000,000 measurements of more than 400 substances starting in 1972. MEGA is used by BIA and the BGs for the following purposes: prevention (e.g., identification of hazards, efficiency of exposure reducing measures, determination of technical criteria for exposure limit values), epidemiological questions, and investigations of occupational diseases. In the framework of the measuring and inspection activities and tasks of the inspectorates of the BGs the locations for measurements are not randomly selected, but are based on criteria such as supposed critical exposure situations or testing the efficiency of exposure reducing measures. Nevertheless, a statistical appraisal of the data is possible for different purposes considering the specific determinants of the results, as, for example, classification of enterprises (sectors), workplaces (activities, tasks), used materials, and products. The MEGA-database will be further developed into a multifactorial exposure database with additional data on biological exposure to bacteria and funghi, but also noise and other data.

[Features of body structure of Estonian young girls and boys]. / Osobennosti teloslozheniia u Estonskikh devushek i iunoshei.

Anthropometric investigation of 670 female students (aged 18-22), 1114 schoolgirls (aged 15-18) and 253 schoolboys (aged 17-18) has demonstrated that the body structure in these samples formed a distinctive system of significantly intercorrelated variables with the body mass and length being the major characteristics. By means of a mass-length (height-weight) classification it is possible to systematize all the single parameters, indices and body composition characteristics. Body mass and length are also assumed as a basis for the formation of extreme pure somatotypes--pycnic and leptosomatic females.

Essential problems in quantification of proteins following colloidal staining with coomassie brilliant blue dyes in polyacrylamide gels, and their solution.

Quantitative determination of stained proteins following polyacrylamide gel electrophoresis (PAGE) is of increasing interest especially since computer-aided densitometers have become available as well as recipes for sensitive and background-free staining with Coomassie Brilliant Blue dyes. However, avoidance of separation artifacts is not the only essential prerequisite for quantitative evaluation. The local particle density of a protein in a given gel is of critical importance since it determines its stainability. Depending on local protein concentration, the dye binding to the same amount of a given protein differs considerably. Since the stainability of proteins using colloidal staining procedures, as with Coomassie Brilliant Blue dyes, is time-dependent and, in addition, also dependent on the pore size of a given polyacrylamide gel used for PAGE, calibration curves for quantitative determinations have to be prepared in polyacrylamide gels of the same composition as used for PAGE. Staining conditions also have to be identical for calibration gels and gels under analysis. If, however, a set of calibration curves is prepared for different staining times, it is possible to calculate a generalized calibration curve, allowing for quantitative evaluation with flexible staining time. Furthermore, and in consequence of the implications due to particle density, quantitative determination via densitometry is only possible by determining the protein amount of each single measuring point (pixel) via its absorbance on the basis of a calibration curve. Since the particle density is inherent in a calibration curve, the final summation of the protein amount per pixel will give values close to reality.