187 research outputs found

    NEW RECORDS FOR THE FAUNA AND ZOOGEOGRAPHY OF CUCKOO WASPS (HYMENOPTERA: CHRYSIDIDAE) IN THE LOWER VOLGA REGION

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    The fauna and zoogeography of chrysidids in the steppe and forest biocenoses of the Lower Volga region in the Saratov region were studied, which include 92 species and 2 subspecies from 17 genera: Cleptes – 2 species; Colpopyga – 1; Elampus – 8; Haba – 1; Hedychridium – 6; Hedychrum – 5; Holopyga – 11; Omalus – 2; Philoctetes – 3; Pseudomalus – 5; Chrysidea – 1; Chrysis – 41; Chrysura – 3; Spinolia – 1; Stilbum – 2; Trichrysis – 1 and Parnopes – 1, among which 69 species are presented for the Saratov region for the first time. Two species, Chrysis corusca Valkeila, 1971 and Chrysis vanlithi Linsenmaier, 1959, and one subspecies Chrysis frivaldszkyi sparsepunctata du Buysson, 1895, are new records for the Russian fauna. The obtained data broaden the understanding of the fauna and diversity of Chrysididae in the Saratov region and the Lower Volga region and supplement the fauna list of the Chrysididae of Russian fauna

    Possible Method for Measuring the Proton Form Factors in Processes with and without Proton Spin Flip

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    The ratio of the squares of the electric and magnetic proton form factors is shown to be proportional to the ratio of the cross sections for the elastic scattering of an unpolarized electron on a partially polarized proton with and without proton spin flip. The initial proton at rest should be polarized along the direction of the motion of the final proton. Similar results are valid for both radiative epep scattering and the photoproduction of pairs on a proton in the Bethe--Heitler kinematics. When the initial proton is fully polarized in the direction of the motion of the final proton, the cross section for the epepep \to ep process, as well as for the epepγep \to ep \gamma and γpeeˉp\gamma p \to e \bar e p processes, without (with) proton spin flip is expressed only in terms of the square of the electric (magnetic) proton form factor. Such an experiment on the measurement of the cross sections without and with proton spin flip would make it possible to acquire new independent data on the behavior of GE2(Q2)G_E^2(Q^2) and GM2(Q2)G_M^2(Q^2), which are necessary for resolving the contradictions appearing after the experiment of the JLab collaboration on the measurement of the proton form factors with the method of polarization transfer from the initial electron to the final proton.Comment: 7 pages, revtex

    One-dimensional Model of a Gamma Klystron

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    A new scheme for amplification of coherent gamma rays is proposed. The key elements are crystalline undulators - single crystals with periodically bent crystallographic planes exposed to a high energy beam of charged particles undergoing channeling inside the crystals. The scheme consists of two such crystals separated by a vacuum gap. The beam passes the crystals successively. The particles perform undulator motion inside the crystals following the periodic shape of the crystallographic planes. Gamma rays passing the crystals parallel to the beam get amplified due to interaction with the particles inside the crystals. The term `gamma klystron' is proposed for the scheme because its operational principles are similar to those of the optical klystron. A more simple one-crystal scheme is considered as well for the sake of comparison. It is shown that the gamma ray amplification in the klystron scheme can be reached at considerably lower particle densities than in the one-crystal scheme, provided that the gap between the crystals is sufficiently large.Comment: RevTeX4, 22 pages, 4 figure

    Broadband optical gain via interference in the free electron laser: principles and proposed realizations

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    We propose experimentally simplified schemes of an optically dispersive interface region between two coupled free electron lasers (FELs), aimed at achieving a much broader gain bandwidth than in a conventional FEL or a conventional optical klystron composed of two separated FELs. The proposed schemes can {\it universally} enhance the gain of FELs, regardless of their design when operated in the short pulsed regime

    European Strategy for Particle Physics -- Accelerator R&D Roadmap

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    The 2020 update of the European Strategy for Particle Physics emphasised the importance of an intensified and well-coordinated programme of accelerator R&D, supporting the design and delivery of future particle accelerators in a timely, affordable and sustainable way. This report sets out a roadmap for European accelerator R&D for the next five to ten years, covering five topical areas identified in the Strategy update. The R&D objectives include: improvement of the performance and cost-performance of magnet and radio-frequency acceleration systems; investigations of the potential of laser / plasma acceleration and energy-recovery linac techniques; and development of new concepts for muon beams and muon colliders. The goal of the roadmap is to document the collective view of the field on the next steps for the R&D programme, and to provide the evidence base to support subsequent decisions on prioritisation, resourcing and implementation.Comment: 270 pages, 58 figures. Editor: N. Mounet. LDG chair: D. Newbold. Panel chairs: P. V\'edrine (HFM), S. Bousson (RF), R. Assmann (plasma), D. Schulte (muon), M. Klein (ERL). Panel editors: B. Baudouy (HFM), L. Bottura (HFM), S. Bousson (RF), G. Burt (RF), R. Assmann (plasma), E. Gschwendtner (plasma), R. Ischebeck (plasma), C. Rogers (muon), D. Schulte (muon), M. Klein (ERL

    Self-amplified spontaneous emission saturation at the Advanced Photon Source free-electron laser (abstract) (invited)

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    This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder

    Состояние легочной микробиоты у мышей С57bl/6 в модели экспериментального туберкулеза

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    The objective: to study the changes in the lung microbiota in inbred C57BL/6 mice after aerogenic infection with M. tuberculosis in an experimental tuberculosis model.Subjects and Methods. This study was carried out on 20 female mice of inbred line C57BL/6 weighing 20-22 grams which were infected in a Glas-Col aerosol chamber (USA) with the culture of M. tuberculosis of virulent strain H37Rv at the dose of 400 CFU/lung. Morphological and microbiological assessment of the lungs state was performed before (day 0) (n=5) and 7 (n=5), 30 (n=5) and 60 (n=5) days after the infection. The results obtained were subjected to statistical processing using ANOVA test and Student t-test.Results. 7, 30, and 60 days after aerosol infection with M. tuberculosis against the background of successive morphological and microbiological changes typical of the experimental tuberculosis model, we established an imbalance of bacterial population in the lung microbiota. Before infection with M. tuberculosis, a scanty biotope was recorded with a predominance of lactobacilli –Lactobacillus murinus, Lactobacillus apodeme. 7, 30 and 60 days after infection with M. tuberculosis, consistent changes were recorded, such as increase in the number and diversity of the bacterial population. The most indicative markers of the recorded imbalance were: Streptococcus thoraltensis, Streptococcus acidominiminus, Arthrobacter crystallopoietes, Staphylococcus hominis, Micrococcus luteus.Conclusion. Tuberculosis infection is a significant factor affecting the state of the lung microbiota. With increased duration of the infection with M. tuberculosis, imbalance of the bacterial flora is formed in the lungs of C57BL/6 mice, accompanied by characteristic tissue inflammation and growing mycobacterial load.Цель исследования: изучить динамику изменений в микробиоте легких у инбредных мышей C57BL/6 после аэрогенного инфицирования M. tuberculosis в модели экспериментального туберкулеза.Материалы и методы. Настоящая работа выполнена на 20 самках мышей инбредной линии C57BL/6, массой 20–22 грамм, которые были заражены в аэрозольной камере Glas-Col (США) культурой Мtb вирулентного штамма H37Rv в дозе 400 КОЕ/легкое. Морфологическую и микробиологическую оценку состояния легких проводили до (день 0) (n=5) и через 7 (n=5), 30 (n=5) и 60 (n=5) дней после инфицирования. Полученные результаты подвергали статистической обработке с использованием теста ANOVA и Стьюдент t-теста.Результаты. Через 7, 30 и 60 дней после аэрозольного инфицирования M. tuberculosis, на фоне последовательных морфологических и микробиологических изменений, характерных для модели экспериментального туберкулеза, нами установлен дисбаланс бактериальной флоры в микробиоте легких. До заражения Mtb регистрировали скудный биотоп с преобладанием лактобацилл – Lactobacillus murinus, Lactobacillus apodeme. Через 7, 30 и 60 дней после инфицирования Mtb регистрировали последовательные изменения в виде увеличения количества и разнообразия бактериального сообщества. Наиболее показательными маркерами регистрируемого дисбаланса были: Streptococcus thoraltensis, Streptococcus acidominiminus, Arthrobacter crystallopoietes, Staphylococcus hominis, Micrococcus luteus.Заключение. Туберкулезная инфекция является значимым фактором, воздействующим на состояние микробиоты легких.С увеличением длительности инфицирования Mtb в легких мышей C57BL/6 формируется дисбаланс бактериальной флоры, сопровождающийся характерным тканевым воспалением и нарастанием микобактериальной нагрузки
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