1,356 research outputs found

    Z radiation off stops at a linear collider

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    We calculate e+e- --> stop/stop/Z at a linear collider. For large splitting between the two stops the cross-section is sensitive to the value of m(stop2) when this particle is too heavy to be directly produced. The results are compared to e+e- --> stop/stop/h.Comment: 19 pages, 8 figure

    Single scalar top production with polarized beams in ep collisions at HERA

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    From the point of view of the R-parity breaking supersymmetric model, we propose a scalar top (stop) search with longitudinally polarized electron (e-) and positron(e+) beams which will soon be available at the upgraded HERA. Fully polarized e- or e+ beams could produce the stop two times as much as unpolarized beams, while they increase background events due to the process of the standard model by about 30% in comparison with unpolarized ones. We show that right-handed e+ beams at HERA is efficient to produce the stop in the model. With 1 fb**(-1) of integrated luminosity we estimate reach in the coupling constant lambda'(131) for masses of the stop in the range 160-400 GeV. We can set a 95% confidence-level exclusion limit for lambda'(131) > 0.01-0.05 in the stop mass range of 240-280 GeV if no singal of the stop is observed. We also point out that y(=Q**2/sx) distributions of e+ coming from the stop shows the different behavior from those of the standard model.Comment: 12 pages, 6 eps figure

    Possible Excess in Charged Current Events with High-Q^2 at HERA from Stop and Sbottom Production

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    We investigate a production process e^+p \to \st X \to \sb W^+ X at HERA, where we consider a decay mode \sb \to \bar{\nu}_e d of the sbottom in the framework of an R-parity breaking supersymmetric standard model. Both processes of the stop production e^+ d \to \st and the sbottom decay \sb \to \bar{\nu}_e d are originated from an R-parity breaking superpotential λ131L^1Q^3Dc^1\lambda'_{131} \hat{L}_1 \hat{Q}_3 \hat{D^c}_1. One of signatures of the process should be a large missing transverse momentum plus multijet events corresponding to hadronic decays of the WW. It is shown that the signal could appear as an event excess in the charged current (CC) processes e+pνXe^+p \to \nu X with the high Q2Q^2 at HERA. We compare expected event distributions with the CC data recently reported by the H1 and ZEUS groups at HERA. Methods for extracting the signal from the standard CC processes are also discussed.Comment: 13 pages, LaTeX, 3 figure

    Spin and spin-spin correlations in chargino pair production at future linear e+e- colliders

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    A possibility to measure the spin and spin-spin correlations of a chargino pair is investigated in the process electron positron -> chargino_1 anti-chargino_1 -> (neutralino_1 quark anti-quark) (neutralino_1 quark anti-quark) at future linear-collider energies. The total and the differential cross sections are calculated by the GRACE system which allows for the full spin correlation. Experimental sensitivity of the measurements are examined by assuming the limited detector resolution, the initial state radiation and the beam-beam effect (beamstrahlung). It is found that generally the spin-spin correlation can only be measured with a lower sensitivity than the chargino spin itself. The dependence of the correlation measurements on the relevant SUSY parameters can be seen for a light sneutrino case, but the situation becomes worse for a heavier sneutrino.Comment: 23 pages, 7 figures, 6 tables; added reference for section

    Deoxycholic Acid as a Modifier of the Permeation of Gliclazide through the Blood Brain Barrier of a Rat

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    Major problem for diabetic patients represents damage of blood vessels and the oxidative stress of the brain cells due to increased concentration of free radicals and poor nutrition of brain cells. Gliclazide has antioxidative properties and poor blood brain barrier (BBB) penetration. Bile acids are known for their hypoglycemic effect and as promoters of drug penetration across biological membranes. Accordingly, the aim of this study is to investigate whether the bile acid (deoxycholic acid) can change the permeation of gliclazide, through the blood brain barrier of a rat model type-1 diabetes. Twenty-four male Wistar rats were randomly allocated to four groups, of which, two were given alloxan intraperitoneally (100 mg/kg) to induce diabetes. One diabetic group and one healthy group were given a bolus gliclazide intra-arterially (20 mg/kg), while the other two groups apart from gliclazide got deoxycholic acid (4 mg/kg) subcutaneously. Blood samples were collected 30, 60, 150, and 240 seconds after dose, brain tissues were immediately excised and blood glucose and gliclazide concentrations were measured. Penetration of gliclazide in groups without deoxycholic acid pretreatment was increased in diabetic animals compared to healthy animals. Also in both, the healthy and diabetic animals, deoxycholic acid increased the permeation of gliclazide through that in BBB

    Implications of the HERA Events for the R-Parity Breaking SUSY Signals at Tevatron

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    The favoured R-parity violating SUSY scenarios for the anomalous HERA events correspond to top and charm squark production via the λ131\lambda'_{131} and λ121\lambda'_{121} couplings. In both cases the corresponding electronic branching fractions of the squarks are expected to be 1\ll 1. Consequently the canonical leptoquark signature is incapable of probing these scenarios at the Tevatron collider over most of the MSSM parameter space. We suggest alternative signatures for probing them at Tevatron, which seem to be viable over the entire range of MSSM parameters.Comment: 20 pages Latex file with 4 ps files containing 4 figure

    Approaches development to formalized description of the disciplinary competence of testable component structure

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    The purpose of this paper is a development of approaches and recommendations on the selection of quantitative and qualitative component structure of disciplinary competencies, as well as ways of its formal description. One of the main problems, which it is necessary to decide while developing a studying and methodical discipline complex (for example, a discipline program, a fund of estimation tools, etc.) of competence-oriented educational program, is designing of a component structure of each part of competence (a disciplinary competence), that is involved in the formation of the discipline. In this case, a significant impact on this process has not only the content of thematic plan and selected kinds of class and self works of students, but proposed control tools and diagnosing methods of learning outcomes specified in the competency format. Methods. It is proposed to use joint (testable) design component structure of disciplinary competencies and control tools (tests, test materials), check the level of development of their constituent elements described in the triad of «to know», «to be able to», «to master». Requirements to the basic quantitative and qualitative properties of disciplinary competence component structure are formulated and substantiated. A structure of diagnostic table that makes it possible to set a correspondence between disciplinary competence elements and components and their control tests, and also to fix outcomes of current control of development level (test reactions in the binary and not binary alphabets) is proposed and analyzed. A classification of diagnostic tests is given; their impact on format and properties of diagnostic table is shown. Scientific novelty. The approach to designing of a testable component structure of disciplinary competence is proposed; it allows setting some properties of control object, which can increase procedure effective and decoding precision of diagnosis of learning outcomes specified in the competency format. The sub product of using some methods of technical diagnosis for their application in the learning outcomes quality control on the competence-oriented educational programs is given. Practical significance. The research implications can be useful while designing of component structure with showing properties, and will allow teachers to make a test procedure more effectively and qualitatively; it is possible for student to estimate more adequately current level of training that is most significantly under a size and role of student self-work increase. The recommendations and guidelines for selection of a diagnostic table format may be used for designing disciplinary programs and estimating of tools funds in educational programs, wherein learning outcomes are specified in the competency format Цель работы – разработка подходов и рекомендаций для выбора количественных и качественных показателей компонентной структуры дисциплинарной компетенции, а также способов ее формализованного описания. Одной из основных задач, которую необходимо решать при создании учебно-методического комплекса дисциплины (ее рабочей программы, фонда оценочных средств и т. д.) и компетентностно-ориентированной образовательной программы, является проектирование компонентной структуры каждой части компетенции (дисциплинарных компетенций). Существенное влияние на данный процесс оказывают не только содержание тематического плана и выбранные виды аудиторной и самостоятельной работы, но и планируемые средства контроля и методы диагностирования результатов обучения, заданных в компетентностном формате. Методы и результаты работы. Предлагается совместное (контролепригодное) проектирование компонентной структуры дисциплинарных компетенций и средств контроля (тестов, контрольно-измерительных материалов), проверяющих уровень освоения их составных элементов, сформулированных в триаде «знать», «уметь», «владеть». Обосновываются требования к основным количественным и качественным показателям компонентной структуры дисциплинарной компетенции. Разработана и проанализирована структура таблицы диагностирования, позволяющая установить соответствие между компонентами дисциплинарных компетенций и контролирующими их тестами, а также зафиксировать результаты текущего контроля уровня освоения. Дана классификация диагностических тестов, показано их влияние на формат и параметры таблицы диагностирования. Научная новизна. Описан подход к формированию контролепригодной компонентной структуры дисциплинарной компетенции, позволяющий придать объекту контроля свойства, повышающие эффективность процедуры и точность дешифрации диагностирования результатов обучения. Представлены частные результаты применения некоторых положений аппарата и методов технической диагностики для их использования в области измерения качества результатов обучения в рамках компетентностно-ориентированных образовательных программ. Практическая значимость. Построение контролепригодной компонентной структуры дисциплинарной компетенции дает возможность педагогу более качественно проводить проверку знаний, а студенту – более адекватно оценивать свои достижения, что особенно важно при увеличении объема самостоятельной работы. Рекомендации по выбору формата таблицы диагностирования могут быть использованы при проектировании рабочих программ и фондов оценочных средств по дисциплинам и разделам образовательных программ, в которых результаты обучения представлены в компетентностном формате

    TLR3, TLR4 and TLRs7-9 Induced Interferons Are Not Impaired in Airway and Blood Cells in Well Controlled Asthma

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    Defective Rhinovirus induced interferon-β and interferon-λ production has been reported in bronchial epithelial cells from asthmatics but the mechanisms of defective interferon induction in asthma are unknown. Virus infection can induce interferon through Toll like Receptors (TLR)3, TLR7 and TLR8. The role of these TLRs in interferon induction in asthma is unclear. This objective of this study was to measure the type I and III interferon response to TLR in bronchial epithelial cells and peripheral blood cells from atopic asthmatics and non-atopic non-asthmatics. Bronchial epithelial cells and peripheral blood mononuclear cells from atopic asthmatic and non-atopic non-asthmatic subjects were stimulated with agonists to TLR3, TLR4 & TLRs7-9 and type I and III interferon and pro-inflammatory cytokine, interleukin(IL)-6 and IL-8, responses assessed. mRNA expression was analysed by qPCR. Interferon proteins were analysed by ELISA. Pro-inflammatory cytokines were induced by each TLR ligand in both cell types. Ligands to TLR3 and TLR7/8, but not other TLRs, induced interferon-β and interferon-λ in bronchial epithelial cells. The ligand to TLR7/8, but not those to other TLRs, induced only type I interferons in peripheral blood mononuclear cells. No difference was observed in TLR induced interferon or pro-inflammatory cytokine production between asthmatic and non-asthmatic subjects from either cell type. TLR3 and TLR7/8,, stimulation induced interferon in bronchial epithelial cells and peripheral blood mononuclear cells. Interferon induction to TLR agonists was not observed to be different in asthmatics and non-asthmatics
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