743 research outputs found
Warp-X: a new exascale computing platform for beam-plasma simulations
Turning the current experimental plasma accelerator state-of-the-art from a
promising technology into mainstream scientific tools depends critically on
high-performance, high-fidelity modeling of complex processes that develop over
a wide range of space and time scales. As part of the U.S. Department of
Energy's Exascale Computing Project, a team from Lawrence Berkeley National
Laboratory, in collaboration with teams from SLAC National Accelerator
Laboratory and Lawrence Livermore National Laboratory, is developing a new
plasma accelerator simulation tool that will harness the power of future
exascale supercomputers for high-performance modeling of plasma accelerators.
We present the various components of the codes such as the new Particle-In-Cell
Scalable Application Resource (PICSAR) and the redesigned adaptive mesh
refinement library AMReX, which are combined with redesigned elements of the
Warp code, in the new WarpX software. The code structure, status, early
examples of applications and plans are discussed
Selective Changes of GABAA Channel Subunit mRNAs in the Hippocampus and Orbitofrontal Cortex but not in Prefrontal Cortex of Human Alcoholics
Alcohol dependence is a common chronic relapsing disorder. The development of alcohol dependence has been associated with changes in brain GABAA channel-mediated neurotransmission and plasticity. We have examined mRNA expression of the GABAA channel subunit genes in three brain regions in individuals with or without alcohol dependence using quantitative real-time PCR assay. The levels of selective GABAA channel subunit mRNAs were altered in specific brain regions in alcoholic subjects. Significant increase in the α1, α4, α5, β1, and γ1 subunit mRNAs in the hippocampal dentate gyrus region, and decrease in the β2 and δ subunit mRNAs in the orbitofrontal cortex were identified whereas no changes in the dorsolateral prefrontal cortex were detected. The data increase our understanding of the role of GABAA channels in the development of alcohol dependence
FINANCIAL RISK MANAGEMENT IN TRADE BANKS
The paper clarifies the concepts of «risk», «financial risk» in banking business, and considers the main problems of financial risk management in trade banks while financing borrowers. The authors single out the most relevant problems, and conduct the analysis of overdue payment in case of OJSC “Sberbank of Russia”. The authors also offer a number of measures to minimize financial risks in trade bank activities in modern conditions
A 64-pixel Positron-Sensitive Surgical Probe
We report on the continued development of a 64-pixel positron-sensitive surgical probe with a dual-layer detector and multi-anode PMT. An 8 x 8 array of this plastic scintillators in teh first layer detects positrons and a matched GSO crystal array in the second layer detects annihilation 511 keV gammas, which are required to be in coincidence with the detected positrons. Also, the 64 PMT anode signals are differentiated and an overshoot threshold is applied to separate the fast decay plastic anode signals from the slower GSO signals. Finally, an energy threshold is applied to the summed anode signal to distinguish 511 keV gammas from the 140 keV gammas commonly used in sentinel lymph node (SLN) surgery. Previously we reported on how these signal selection criteria were individually tested and optimized based on 9 channels of prototype electronics [1-2]. Currently the electronics shave been upgraded to Xilinx® programmable components, allowing on-the-fly alteration of signal selection criteria, and all 64 channels are operational. Initial measurements of the complete 64-pixel probe were conducted using 18F-FDG positron sources and 18F-FDG and 99mTcphantoms (background 511 keV and 140 keV gammas), simulating lesions in the SLN surgery environment. The average positron sensitivity is measured to be 3.0-7.0 kcps/µCi at different signal selection criteria. The lower bound on sensitivity corresponds to settings optimized for high image resolution and high background rejection ability. The upper bound on sensitivity corresponds to settings optimized for high sensitivity at the cost of lower image resolution and lower background rejection ability. The measured true-to-background contrast in the presence of clinically observed levels of 511 keV and 140 keV background gammas is ~3:1 for a tumor-to-background uptake ratio of 5:1. Performance measurements of the complete 64-pixel probe including sensitivity, true-to-background ratio, and the pixel separation ability are presented
The place of virome in women’s reproductive health
Introduction. The vaginal ecosystem is rich in bacteria, the simplest, fungi as well as viruses that are now introduced by the concept of virome. The lack of knowledge of the role of the virome, especially its impact on reproductive and sexual health, aims to study scientific literature on this issue.The purpose of this review is to provide up-to-date data on vaginal virome, its relationship with vaginal microbiota and outcomes of pregnancy, and its impact on reproductive and sexual health.Material and methods. An information search was carried out using Internet resources (PubMed, Web of Science, eLibrary.ru); literature sources for period 2016–2021 were analyzed.Results. The analysis of the scientific data demonstrated the importance of studying the vaginal virome, its role in the development of gynecological and obstetric pathologies the relationship of vaginal viruses with microbiota and immune system of the host organism. And any imbalance of this relationship can contribute to adverse reproductive outcomes, including the infertility.Conclusion. The growing interest in the investigation of vaginal virome requires standardization of laboratory protocols and technologies, including the identification of RNA viruses. However, there are methodological and analytical restrictions on the vaginal virome research. It is suggested that vaginal virome is the missing link between the bacteria of the female genital tract with protective properties of the mucous membranes and adverse reproductive outcomes. In this regard, future studies that assess vaginal virome in the balance between disease and health are very promising
Гістологічна оцінка гепатопротекторної активності водного екстракту листків кукурудзи при гострому токсичному ураженні печінки
Conducted histomorphological assessment of the impact on the state Wellcome liver in acute hepatitis tetrahlormetanovoho in rats. These histological studies have shown that Wellcome 50 mg / kg on the model of acute toxic liver damage in rats induced by carbon tetrachloride, showed clear hepatoprotective effect, manifested in antynekrotychniy, antydystrofichniy action, accelerate the process of physiological regeneration of hepatocytes. On power hepatoprotective impact in terms of toxic liver damage Wellcome to some extent a superior effect of comparator Silibor.Проведена гистоморфологического оценка воздействия Велком на состояние печени в условиях острого тетрахлорметанового гепатита у крыс. Данные гистологического исследования показали, что велкам в дозе 50 мг / кг на модели острого токсического поражения печени у крыс, вызванного тетрахлорметаном, проявлял выразительный гепатопротекторный эффект, что проявлялось в антинекротичний, антидистрофичний действия, ускорении процессов физиологической регенерации гепатоцитов. По мощности гепатозахисну воздействия в условиях токсического поражения печени Велком в определенной степени превосходит такой эффект препарата сравнения силибора.Проведена гістоморфологічна оцінка впливу ВЕЛК на стан печінки в умовах гострого тетрахлорометанового гепатиту у щурів. Дані гістологічного дослідження показали, що ВЕЛК у дозі 50 мг/кг на моделі гострого токсичного ураження печінки у щурів, викликаного тетрахлорометаном, виявляв виразний гепатопротекторний ефект, що проявлялося в антинекротичній, антидистрофічній дії, прискоренні процесів фізіологічної регенерації гепатоцитів. За потужністю гепатозахисного впливу в умовах токсичного ураження печінки ВЕЛК певною мірою перевершує такий ефект препарату порівняння «Силібор»
El estudio pedagógico como tecnología de formación docente
The modern development of teacher training system demonstrates the rethinking of teacher professional competences and focuses on general pedagogical, educational, methodological and psychological skills of a comprehensive school teacher. Improving the effectiveness of school education makes high demands on the personal qualities and professional competences of a teacher. In the new socio-economic conditions the approaches to the organization and content of methodological work in terms of in-service teacher training are changing. The successful pedagogical process is largely determined by the activity of emotionally secure, socially and professionally competent teacher, ready to continuing professional development. It implies a broad general cultural background, mastering of reflective skills. The study of these problems is associated with the increasing role of professional components in the development of teacher as a highly qualified specialist. This is due to the multidimensional scope of teacher’s activities, research attitude to the work, readiness to implement innovations. Such specialists make it possible to provide methodological support and i-service training of teachers at a qualitatively new level.El desarrollo moderno del sistema de formación docente demuestra el replanteamiento de las competencias profesionales docentes y se centra en las habilidades pedagógicas, educativas, metodológicas y psicológicas generales de un maestro escolar integral. Mejorar la efectividad de la educación escolar exige mucho sobre las cualidades personales y las competencias profesionales de un maestro. En las nuevas condiciones socioeconómicas, los enfoques para la organización y el contenido del trabajo metodológico en términos de capacitación docente en servicio están cambiando. El exitoso proceso pedagógico está determinado en gran medida por la actividad de un maestro emocionalmente seguro, social y profesionalmente competente, listo para continuar el desarrollo profesional. Implica un amplio trasfondo cultural general, el dominio de las habilidades reflexivas. El estudio de estos problemas está asociado con el creciente papel de los componentes profesionales en el desarrollo del maestro como especialista altamente calificado. Esto se debe al alcance multidimensional de las actividades de los docentes, la actitud investigadora hacia el trabajo, la disposición para implementar innovaciones. Dichos especialistas hacen posible brindar apoyo metodológico y capacitación i-service de docentes a un nivel cualitativamente nuevo
A new assay for measuring chromosome instability (CIN) and identification of drugs that elevate CIN in cancer cells.
BACKGROUND: Aneuploidy is a feature of most cancer cells that is often accompanied by an elevated rate of chromosome mis-segregation termed chromosome instability (CIN). While CIN can act as a driver of cancer genome evolution and tumor progression, recent findings point to the existence of a threshold level beyond which CIN becomes a barrier to tumor growth and therefore can be exploited therapeutically. Drugs known to increase CIN beyond the therapeutic threshold are currently few in number, and the clinical promise of targeting the CIN phenotype warrants new screening efforts. However, none of the existing methods, including the in vitro micronuclei (MNi) assay, developed to quantify CIN, is entirely satisfactory. METHODS: We have developed a new assay for measuring CIN. This quantitative assay for chromosome mis-segregation is based on the use of a non-essential human artificial chromosome (HAC) carrying a constitutively expressed EGFP transgene. Thus, cells that inherit the HAC display green fluorescence, while cells lacking the HAC do not. This allows the measurement of HAC loss rate by routine flow cytometry. RESULTS: Using the HAC-based chromosome loss assay, we have analyzed several well-known anti-mitotic, spindle-targeting compounds, all of which have been reported to induce micronuclei formation and chromosome loss. For each drug, the rate of HAC loss was accurately measured by flow cytometry as a proportion of non-fluorescent cells in the cell population which was verified by FISH analysis. Based on our estimates, despite their similar cytotoxicity, the analyzed drugs affect the rates of HAC mis-segregation during mitotic divisions differently. The highest rate of HAC mis-segregation was observed for the microtubule-stabilizing drugs, taxol and peloruside A. CONCLUSION: Thus, this new and simple assay allows for a quick and efficient screen of hundreds of drugs to identify those affecting chromosome mis-segregation. It also allows ranking of compounds with the same or similar mechanism of action based on their effect on the rate of chromosome loss. The identification of new compounds that increase chromosome mis-segregation rates should expedite the development of new therapeutic strategies to target the CIN phenotype in cancer cells
Using the methods to calculate parameters of drilling and blasting operations for emulsion explosives
Mathematical modelling of rock mass breaking using blasting has been applied to obtain formulas for the calculation of crush zone radii, intensive fragmentation, and crack formation around the charging cavity in the structure, diameter of the charging cavity, diameter of the charge itself, detonation characteristics of an explosive, boundaries of the rock strength, rock mass jointing, and mineral compression under the effect of rock pressure. The methods have been developed to calculate parameters of drilling and blasting operations (DBOs) while driving the mine workings based upon the idea of the arrangement of blastholes in terms of areas they occupy in a fore-breast as well as upon their location relative to break-off outline. Stage one of the methods involves calculating and designing burn cuts where a distance between blastholes is determined with the help of a fragmentation zone radius. Stage two means calculation of both specific and total explosion consumption per borehole bottom, line of least resistance (LLR) for a borehole in terms of intensive fragmentation, areas of borehole groups, borehole number, analytical and actual distance between boreholes, actual charge amount per borehole, and actual specific and the total explosive (E) consumption per borehole bottom. The methods have been tested in the operating ore mine while driving a mine working. Emulsion explosive (EE) Ukrayinit-PP-2 (Україніт-ПП-2) has been applied. The developed methods have been used to calculate DBOs parameters for the explosive. Trial blasts demonstrated the good firing of a borehole bottom and uniform ore fragmentation; a high coefficient of borehole use has been supported
An experiment with association rules and classification: post-bagging and conviction
In this paper we study a new technique we call post-bagging, which consists in
resampling parts of a classification model rather then the data. We do
this with a particular kind of model: large sets of classification association rules, and
in combination with ordinary best rule and weighted voting approaches.
We empirically evaluate the effects of the technique in terms of classification accuracy.
We also discuss the predictive power of different metrics used for association rule mining, such as confidence, lift, conviction and X². We conclude that, for the described experimental conditions, post-bagging improves classification results and that the best metric is conviction.Programa de Financiamento Plurianual de Unidades de I & D.Comunidade Europeia (CE). Fundo Europeu de Desenvolvimento Regional (FEDER).Fundação para a Ciência e a Tecnologia (FCT) - POSI/SRI/39630/2001/Class Project
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