СОВРЕМЕННЫЙ ВЗГЛЯД НА ПРОБЛЕМУ РЕТИНОПАТИИ НЕДОНОШЕННЫХ

The article presents a review of the data, which reflects the relevance and modern views on the problem of retinopathy of prematurity, including statistical and epidemiologic data on nosology. Various pathogenetic theories of onset and progression of this disease are discussed. A clear correlation depending on the degree of prematurity, body weight and physical condition of the newborn and the risk of disease is mentioned. The summation of etiology aspects, as well as pathogenesis, classification of clinical forms and the modern approach to the diagnostics is of a quite interest. The article also describes different treatment strategies which include various methods of conservative therapy and surgery, depending on the course and stage of disease. Rehabilitation activities for children who had come through some stage of retinopathy of prematurity and are at risk for the formation of different ophthalmopathology such as refractive errors and pathology of binocular vision in the future and require a subsequent long-term monitoring in the office catamnesis are itemized. The importance of interaction between ophthalmologists and neonatologists at all stages of neonatal screening for providing timely specialized care in order to minimize the occurrence of retinopathy and prevent progression to disabling stages, as well as to improve the quality of life of these patients is shown.В статье представлен обзор данных, отражающих актуальность и современные взгляды на проблему ретинопатии недоношенных, включая статистические и эпидемиологические данные по нозологии заболевания. Рассмотрены различные патогенетические теории возникновения и прогрессирования данной патологии. Указана четкая корреляция в зависимости от степени недоношенности, массы тела, соматического состояния новорожденного и риска возникновения заболевания. Интерес представляет суммирование аспектов этиологии, патогенеза, классификации клинических форм, а также современный подход к диагностике. Также в статье описана тактика лечения, включающая различные методики консервативной терапии и хирургических вмешательств в зависимости от течения и стадии заболевания. Перечислены реабилитационные мероприятия, которые необходимо проводить с учетом того, что дети, перенесшие некоторые стадии ретинопатии недоношенных, входят в группу риска по формированию различной офтальмопатологии, например аномалий рефракции и патологии бинокулярного зрения в будущем, и нуждаются в последующем длительном наблюдении в кабинете катамнеза. Показана важность взаимодействия неонатологов и офтальмологов на всех этапах неонатального скрининга для оказания своевременной специализированной помощи с целью минимизации риска возникновения ретинопатии и предотвращения прогрессирования заболевания до инвалидизирующих стадий, а также улучшения качества жизни данной категории пациентов.

Процедура установления соединения по радиоканалу случайного доступа с возможностью ретрансляции

Due to the rapidly growing number of user’s equipments, operating in the LTE (Long-Term Evolution) mobile radio network, it became necessary to find methods to reduce the user load and signaling message’s traffic. New rules and procedures of devices communication are created to downsize network resources. This article explores the procedure for establishing a connection between mobile user’s equipment and the LTE base station. Such possible solution of transferring small data generated by machine-to-machine connections (M2M, Machine-to-Machine) was presented in the technical report TR 37.868 of the 3GPP consortium (3rd Generation Partnership Project). This approach implies the use of the random access channel (RACH) to interconnect between devices. Effective usage of the procedure for establishing a connection through a random access radio channel is based on the analysis of time-probability characteristics, such as the access success probability and failed access probability, average access delay. In this article we proposed analytical model in term of Markov chain to find these characteristics and present numerical analysis, considering collisions of preamble message, retransmissions of signalling messages and the boundary conditions on the number of possible retransmissions. The accuracy of the proposed analytical model was verified using programming environment R.В связи с быстро растущим числом абонентских устройств, функционирующих в сети беспроводной мобильной связи LTE (Long-Term Evolution), возникла необходимость поиска методов снижения пользовательской и обслуживающей сигнальной нагрузки. Для сокращения объёмов сетевых ресурсов создаются правила, упрощающие взаимодействие устройств внутри сети. В данной статье исследуется процедура установления соединения между устройством и базовой станцией LTE. Одно из возможных решений задачи передачи малых данных, генерируемых при межмашинном соединении (M2M, Machine-to-Machine), было представлено в техническом отчёте TR 37.868 консорциума 3GPP (3rd Generation Partnership Project). Данное предложение подразумевает использование радиоканала случайного доступа RACH (Random Access Channel) для соединения между устройствами. Эффективное использование процедуры установления соединения по радиоканалу случайного доступа основывается на анализе вероятностно-временных характеристик, таких как вероятность успешного и неуспешного установления соединения, средняя задержка успешного установления соединения. В данной статье исследована зависимость перечисленных характеристик от вероятности коллизии, возможной при передаче преамбулы, и граничных условий на количество возможных ретрансляций сообщений, используемых в процедуре установления соединения. Точность и достоверность расчётов, получаемых при использовании предлагаемой аналитической модели, была проверена с помощью имитационного моделирования на языке R

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO

Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV

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