50 research outputs found

    On parabolic Whittaker functions

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    We derive a Mellin-Barnes integral representation for solution to generalized (parabolic) quantum Toda lattice introduced in \cite{GLO}, which presumably describes the (S1×UN)(S^1\times U_N)-equivariant Gromov-Witten invariants of Grassmann variety.Comment: 14 page

    Normalizers of maximal tori and real forms of Lie groups

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    For a complex reductive Lie group GG Tits defined an extension WGTW_G^T of the corresponding Weyl group WGW_G. The extended group is supplied with an embedding into the normalizer NG(H)N_G(H) of the maximal torus HGH\subset G such that WGTW_G^T together with HH generate NG(H)N_G(H). We give an interpretation of the Tits classical construction in terms of the maximal split real form G(R)G(C)G(\mathbb{R})\subset G(\mathbb{C}), leading to a simple topological description of WGTW^T_G. We also propose a different extension WGUW_G^U of the Weyl group WGW_G associated with the compact real form UG(C)U\subset G(\mathbb{C}). This results into a presentation of the normalizer of maximal torus of the group extension UGal(C/R)U\ltimes {\rm Gal}(\mathbb{C}/\mathbb{R}) by the Galois group Gal(C/R){\rm Gal}(\mathbb{C}/\mathbb{R}). We also describe explicitly the adjoint action of WGTW_G^T and WGUW^U_G on the Lie algebra of GG.Comment: 17 page

    On q-deformed gl(l+1)-Whittaker function II

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    A representation of a specialization of a q-deformed class one lattice gl(\ell+1}-Whittaker function in terms of cohomology groups of line bundles on the space QM_d(P^{\ell}) of quasi-maps P^1 to P^{\ell} of degree d is proposed. For \ell=1, this provides an interpretation of non-specialized q-deformed gl(2)-Whittaker function in terms of QM_d(\IP^1). In particular the (q-version of) Mellin-Barnes representation of gl(2)-Whittaker function is realized as a semi-infinite period map. The explicit form of the period map manifests an important role of q-version of Gamma-function as a substitute of topological genus in semi-infinite geometry. A relation with Givental-Lee universal solution (J-function) of q-deformed gl(2)-Toda chain is also discussed.Comment: Extended version submitted in Comm. Math. Phys., 24 page

    The State of Hip Arthroscopy in Russia: Assessment Based on a Sociological Survey of Doctors

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    Background. Hip arthroscopy is a minimally invasive surgical technique most commonly performed to correct femoroacetabular impingement (FAI). Currently, it is widely used by worldwide; in addition, there are a significant number of english-language publications on this topic. The number of hip arthroscopy performed in Russia is unknown. Information about this surgical technique is also very limited in our country. The aim of the study was to assess the level of hip arthroscopy in Russia. Methods. A total sociological survey of orthopaedic surgeon with experience in performing hip arthroscopy was conducted. The questionnaire was posted on the Google Forms platform and consisted of 13 questions of closed, semi-closed and open types. The survey included 54 surgeons from Russian clinics, 45 people filled out the questionnaire. Results. Among the respondents, doctors with experience in performing arthroscopic operations on the knee and shoulder joints predominated (100.000.00% and 93.300.03%, respectively). The majority of specialists (73.300.06%) were trained in hip arthroscopy during the primary course in one of the clinics in Russia. More than half of the respondents (68.800.06%) are currently engaged in this surgical area, however, in 45.160.07% of them, the number of operations does not exceed 5 per year. For surgeons who have completed two or more training courses, the volume of operations performed is higher (p0.05); 51.110.07% of doctors perform arthroscopy using an alternative technique. There are 2.5 time more specialists doing just bone resection, than surgeons who apply any kind of reconstruction technique while treating FAI (p0.05). Fifteen respondents (48.390.08%) perform debridement as an attempt to delay arthroplasty. The most common difficulties faced by surgeon are problems with the diagnosis of FAI (no patients) (40.000.02%), lack of the necessary tools (40.000.02%) and sufficient time to master the technique (33.300.07%). Only three (6.600.07%) respondents believe that they manage to achieve the planned results of the operation, 93.300.03% of surgeons said that it is not always possible to achieve the desired outcomes. Conclusion. Hip arthroscopy in Russia is not very common, the volume of such interventions is insignificant. Doctors with minimal skills in arthroscopic hip surgery predominate. Factors that impede the development of this area in our country are related to teaching methods, problems with FAI diagnostics, the lack of necessary instruments for performing operations, and the lack of time for specialists to master surgical techniques

    Stone Age Research in the Narva–Luga Klint Bay Area in 2005–2014

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    The Narva–Luga micro-region, situated on the border of Estonia and Russia in north-eastern Europe, has been the target of international and interdisciplinary research conducted annually between 2005 and 2014. During this time, altogether 42 new archaeological sites have been discovered, and many sites have also been excavated – in addition, a large amount of natural scientific data has been collected. All in all, over 60 Stone Age and Bronze Age sites are currently known in this micro-region. The sites date mostly between the late 6th and late 3rd millennia calBC, that is, to the cultural contexts of Narva Ware, Comb Ware, and Corded Ware. In this paper, some of the main results of the archaeological studies made during the last decade are briefly summarised

    Normalizers of maximal tori and real forms of Lie groups

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    Given a complex connected reductive Lie group G with a maximal torus H⊂G, Tits defined an extension WTG of the corresponding Weyl group WG. The extended group is supplied with an embedding into the normalizer NG(H) such that WTG together with H generate NG(H). In this paper we propose an interpretation of the Tits classical construction in terms of the maximal split real form G(R)⊂G, which leads to a simple topological description of WTG. We also consider a variation of the Tits construction associated with compact real form U of G. In this case we define an extension WUG of the Weyl group WG, naturally embedded into the group extension U˜:=U⋊Γ of the compact real form U by the Galois group Γ=Gal(C/R). Generators of WUG are squared to identity as in the Weyl group WG. However, the non-trivial action of Γ by outer automorphisms requires WUG to be a non-trivial extension of WG. This gives a specific presentation of the maximal torus normalizer of the group extension U˜. Finally, we describe explicitly the adjoint action of WTG and WUG on the Lie algebra of G

    Crowdsourcing Fungal Biodiversity : Revision of Inaturalist Observations in Northwestern Siberia

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    The paper presents the first analysis of crowdsourcing data of all observations of fungi (including lichens) and myxomycetes in Northwestern Siberia uploaded to iNaturalist.org to date (24.02.2022). The Introduction presents an analysis of fungal diversity crowdsourcing globally, in Russia, and in the region of interest. Materials and methods describe the protocol of uploading data to iNaturalist.org, the structure of the crowdsourcing community. initiative to revise the accumulated data. procedures of data analysis, and compilation of a dataset of revised crowdsourced data. The Results present the analysis of accumulated data by several parameters: temporal, geographical and taxonomical scope, observation and identification efforts, identifiability of various taxa, species novelty and Red Data Book categories and the protection status of registered observations. The Discussion provides data on usability of crowdsourcing data for biodiversity research and conservation of fungi, including pros and contras. The Electronic Supplements to the paper include an annotated checklist of observations of protected species with information on Red Data Book categories and the protection status, and an annotated checklist of regional records of new taxa. The paper is supplemented with a dataset of about 15 000 revised and annotated records available through Global Biodiversity Information Facility (GBIF). The tradition of crowdsourcing is rooted in mycological societies around the world, including Russia. In Northwestern Siberia, a regional mycological club was established in 2018, encouraging its members to contribute observations of fungi on iNaturalist.org. A total of about 15 000 observations of fungi and myxomycetes were uploaded so far, by about 200 observers, from three administrative regions (Yamalo-Nenetsky Autonomous Okrug, Khanty-Mansi Autonomous Okrug, and Tyumen Region). The geographical coverage of crowdsourcing observations remains low. However. the observation activity has increased in the last four years. The goal of this study consisted of a collaborative effort of professional mycologists invited to help with the identification of these observations and analysis of the accumulated data. As a result, all observations were reviewed by at least one expert. About half of all the observations have been identified reliably to the species level and received Research Grade status. Of those, 90 species (195 records) represented records of taxa new to their respective regions: 876 records of 53 species of protected species provide important data for conservation programmes. The other half of the observations consists of records still under-identified for various reasons: poor quality photographs, complex taxa (impossible to identify without microscopic or molecular study). or lack of experts in a particular taxonomic group. The Discussion section summarises the pros and cons of the use of crowdsourcing for the study and conservation of regional fungal diversity, and summarises the dispute on this subject among mycologists. Further research initiatives involving crowdsourcing data must focus on an increase in the quality of observations and strive to introduce the habit of collecting voucher specimens among the community of amateurs. The timely feedback from experts is also important to provide quality and the increase of personal involvement.Peer reviewe

    Моделирование функциональных кист яичников путем введения фолликулостимулирующего гормона

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    Aim. To study the morphofunctional state of ovaries after the introduction of recombinant FSH. Materials and methods. Two groups of mature female Wistar rats were used in the study. The experimental group consisted of 35 rats with a model of follicular ovarian cysts, while 25 rats were in the control group.Rats were taken out of the experiment on days 3, 7, 15, 30 and 60. Paraffin slides of ovaries were stained with hematoxylin and eosin by Van Gieson. Histological and morphometric investigations were performed.Results. On day 7 of FSH administration, the maximum increase in the size of the ovaries was observed due to the formation of single-cell follicular cysts. Rats in the experimental group showed a marked decrease in the number of growing follicles on day 7 and 15. The increase in atretic bodies and follicles in comparison with the control group was observed on day 7 and lasted until the end of the experiment. Additionally, on day 7 of the experiment, hyperemia and vasoconstriction were noted. The number of yellow bodies decreased during the experiment, and an increase in collagen formation occurred starting from day 15 of the experiment.Conclusion. The introduction of follicle-stimulating hormone for 7 days leads to disruption of folliculogenesis, strengthening of atresia in the ovaries, and the formation of functional cysts.Цель исследования. Изучить морфологические изменения яичников при введении рекомбинантного фолликулостимулирующего гормона.Материал и методы. Эксперимент проведен на половозрелых белых самках крыс линии Wistar. Основную группу составили 35 животных с моделью функциональных кист яичников, контрольную – 25 интактных животных. Крысы выводились из эксперимента на 3-и, 7-е, 15-, 30- и 60-е сут. Проведены гистологическое и морфометрическое исследования на депарафинированных срезах яичников, окрашенных гематоксилином и эозином и по Ван Гизону.Результаты. На 7-е сут введения фолликулостимулирующего гормона наблюдалось максимальное увеличение размеров яичников за счет формирования однокамерных функциональных кист. У животных основной группы отмечалось выраженное снижение количества растущих фолликулов на 7- и 15-е сут.Увеличение количества атретических фолликулов и тел по сравнению с таковым в группе контроля наблюдалось с 7-х сут и продолжалось до 60-х сут эксперимента. На 7-е сут эксперимента отмечались гиперемия и полнокровие сосудов. Количество желтых тел уменьшалось в ходе эксперимента. Отмечалось усиление процессов коллагенообразования, начиная с 15-х сут эксперимента.Заключение. Введение фолликулостимулирующего гормона в течение 7 сут приводит к нарушению процессов фолликулогенеза, усилению процессов атрезии в яичниках и формированию функциональных кис
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