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The second generation of the compact HiSIM_IGBT model for circuit simulation is reported. HiSIM_IGBT2 is developed on the basis of an adapted version of the high-voltage mosfet model HiSIM_HV and solves the Poisson equation along the complete device iteratively in a consistent way. The major HiSIM_IGBT2 improvement concerns the description of the mosfet contribution to the dynamically varying resistance effect in the base-region of the bipolar transistor (BJT) part of the insulated gate bipolar transistor (IGBT). An important finding is that the IGBT mostly operates under the high-injection condition, namely, under the drift mechanism for the transport of the injected carriers, and that a subtle balancing of the contributions from bipolar control and mosfet control of the IGBT is required. The developed model is verified with 2-D-numerical device simulation to accurately reproduce the potential distribution within the IGBT. Therefore, the specific IGBT features, induced by the highly resistive base region under the high-injection condition, are self-consistently captured. The developed model is proven to provide stable circuit simulations with accurate reproduction of the switching performances. [ABSTRACT FROM AUTHOR]

Estimation of human leukocyte antigen ( HLA) haplotype frequencies from unrelated stem cell donor registries presents a challenge because of large sample sizes and heterogeneity of HLA typing data. For the 14th International HLA and Immunogenetics Workshop, five bioinformatics groups initiated the 'Registry Diversity Component' aiming to cross-validate and improve current haplotype estimation tools. Five datasets were derived from different donor registries and then used as input for five different computer programs for haplotype frequency estimation. Because of issues related to heterogeneity and complexity of HLA typing data identified in the initial phase, the same five implementations, and two new ones, were used on simulated datasets in a controlled experiment where the correct results were known a priori. These datasets contained various fractions of missing HLA-DR modeled after European haplotype frequencies. We measured the contribution of sampling fluctuation and estimation error to the deviation of the frequencies from their true values, finding equivalent contributions of each for the chosen samples. Because of patient-directed activities, selective prospective typing strategies and the variety and evolution of typing technology, some donors have more complete and better HLA data. In this setting, we show that restricting estimation to fully typed individuals introduces biases that could be overcome by including all donors in frequency estimation. Our study underlines the importance of critical review and validation of tools in registry-related activity and provides a sustainable framework for validating the computational tools used. Accurate frequencies are essential for match prediction to improve registry operations and to help more patients identify suitably matched donors. [ABSTRACT FROM AUTHOR]

The human leukocyte antigen (HLA) distribution in donor registry data is typically nonrandom as, mostly for economical reasons, typing additional loci or resolving ambiguities is selectively performed based on the previously known HLA type. Analyzing a sample of over 1 million German stem cell donors, we practically show the extent of the bias caused by the restriction of the input data for HLA haplotype frequency (HF) estimation to subsets selected according to their higher HLA typing resolution and, conversely, the correctness of estimates based on unselected data with a methodology suitable for heterogeneous resolution. We discuss algorithmic aspects of this approach and, also because of the sample size, provide some new insights into the distribution of HLA-DRB1 alleles in the German population and the application of HFs in unrelated donor search. [ABSTRACT FROM AUTHOR]

The economic devastation caused in the past by the New World screwworm fly Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) to the livestock industry in the U.S.A., Mexico and the rest of Central America was staggering. The eradication of this major livestock pest from North and Central America using the sterile insect technique (SIT) as part of an area-wide integrated pest management (AW-IPM) programme was a phenomenal technical and managerial accomplishment with enormous economic implications. The area is maintained screwworm-free by the weekly release of 40 million sterile flies in the Darien Gap in Panama, which prevents migration from screwworm-infested areas in Columbia. However, the species is still a major pest in many areas of the Caribbean and South America and there is considerable interest in extending the eradication programme to these countries. Understanding New World screwworm fly populations in the Caribbean and South America, which represent a continuous threat to the screwworm-free areas of Central America and the U.S.A., is a prerequisite to any future eradication campaigns. The Old World screwworm fly Chrysomya bezziana Villeneuve (Diptera: Calliphoridae) has a very wide distribution ranging from Southern Africa to Papua New Guinea and, although its economic importance is assumed to be less than that of its New World counterpart, it is a serious pest in extensive livestock production and a constant threat to pest-free areas such as Australia. In the 1980s repeated introductions and an expansion of Old World screwworm populations were reported in the Middle East; in the 1990s it invaded Iraq and since late 2007 it has been reported in Yemen, where a severe outbreak of myiasis occurred in 2008. Small-scale field trials have shown the potential of integrating the SIT in the control of this pest and various international organizations are considering using the release of sterile insects as part of an AW-IPM approach on a much wider scale. Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae) is a screwworm of temperate regions, which, although of limited agricultural importance, has invaded several new locations in the past few years. This special issue reports on the results of a 6-year project funded by the Joint Food and Agriculture Organization of the United Nations/International Atomic Energy Agency (FAO/IAEA) Programme of Nuclear Techniques in Food and Agriculture entitled ‘Enabling Technologies for the Expansion of the SIT for Old and New World Screwworm’. A major goal of the project was to better understand population genetic variation in screwworms as an aid to the identification of isolated populations. The project also addressed issues related to genetic sexing, cuticular hydrocarbons, population dynamics, genetic transformation and chromosome analysis. [ABSTRACT FROM AUTHOR]

Objectives: A gain in life expectancy of a population is commonly interpreted as an effect of improved health care. After the reunion of Germany in 1990 life expectancy at birth grew extremely in the new federal states. Within one decade after reunion the new federal states had a gain in life expectancy of about five years while the gain in the old federal states was only about two years.Methods: It has been widely argued that this phenomenon is caused by an obviously improved public health service and environmental protection or even by an increased social status in the new federal states. On the other hand, the median population age grew rapidly in the new federal states, caused by a dramatic reduction of the birth rate as well as a high emigration rate of young people. Using real time series for three selected federal states and for the total Federal Republic of Germany, it is derived that most of the gain in life expectancy is explained by population ageing.Results: An elementary probabilistic procedure is proposed allowing for estimating the amount in life expectancy not attributable to population ageing.Conclusions: The age-adjusted life expectancy can be regarded as an unbiased measure of a populations' state of health that stays comparable both over time and across countries. [ABSTRACT FROM AUTHOR]

In euthyroidism the circadian rhythm and pulsatility of TSH is well known. With regard to hyperthyroidism only very preliminary data were described. In this tudy we investigated the secretion pattern of the pituitary-thyroid axis hormones during 24 h in latent and overt hyperthyroidism and in euthyroidism with regard to common and different properties. Blood was obtained for 24 h at 10-min intervals. In euthyroidism we found intraindividually three overlapping patterns of TSH, which are different in amplitude and frequency and can be found interindividually, too. These patterns are equal to the circadian rhythm, pulsatile secretion and lastly to the methodic rustle. The circadian rhythm in latent hyperthyroidism is distinctly suppressed and in overt hyperthyroidism totally. Whereas in latent hyperthyroidism pulsatile secretion is extant, in overt hyperthyroidism the TSH pulses are absent. To record the patients' TSH circadian rhythm with only three blood samples, we defined the TSH-Triplex. In young as well as in elderly healthy volunteers it demonstrated significantly higher TSH levels at midnight (at 24:00 h) than it did at 4 p.m. and 8 a.m. The present study shows a significantly different TSH pattern in latent hyperthyroidism compared to euthyroidism. It should be discussed whether latent hyperthyroidism could be defined as hyperthyroidism stage I. On the other hand, latent hyperthyroidism could be an illness with its own cause, different from hyperthyroidism. Our data suggest that the laboratory findings of latent hyperthyroidism in each age are non-physiological. However, the cause for this disorder is unclear until now; hence further investigations are necessary. [ABSTRACT FROM AUTHOR]

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