Alternating current driven instability in magnetic junctions

An effect is considered of alternating (high-frequency) current on the spin-valve type magnetic junction configuration. The stability with respect to small fluctuations is investigated in the macrospin approximation. When the current frequency is close to the eigenfrequency (precession frequency) of the free layer, parametric resonance occurs. Both collinear configurations, antiparallel and parallel ones, can become unstable under resonance conditions. The antiparallel configuration can become unstable under non-resonant conditions, also. The threshold current density amplitude is of the order of the dc current density switching the magnetic junction.Comment: 8 page

Mapping the city scale anthropogenic heat emissions from buildings in Kuala Lumpur through a top-down and a bottom-up approach

The warming urban climates increase the building energy consumption by changing the heating/cooling loads of the buildings. On the other hand, building induced anthropogenic heat emissions can also contribute to the urban heating, creating a warming feedback loop. Such impact is more profound in the (sub)tropical and hot/arid context, where Air Conditioning (AC) systems are widely used. A better understanding of the building energy consumption and its contribution to urban heating can therefore help mitigate urban heating. To this end, we aim to estimate building energy use and induced heat emissions in Kuala Lumpur, Malaysia, using both a bottom-up strategy based on building energy modelling and a top-down strategy based on national scale energy inventory. We further integrate the building energy model with measured diurnal temperature profiles at different land use areas, to discuss the impact of urban heat island (UHI) on energy use, and potential mitigation strategies through different urban morphologies. The estimated energy use obtained via both bottom-up and the top-down approaches were within the range of actual energy use from case studies available for Kuala Lumpur. It also highlights the need to adapt multi-scale strategies to mitigate the building energy use, and the associated impacts on the UHI

Chadwick GreenBIM: Advancing Operational Understanding of Historical Buildings with BIM to Support Sustainable Use

Chadwick GreenBIM is an initiative to establish a digital 3D as-built model of UCL’s Chadwick Building including embedded environmental data to gain a greater understanding of its operation with the aim of developing concepts for retrofit and sustainable use. This paper investigates the above by reviewing the state of the art in reality capture to generate a parametric model using laser scanning. It also considers the challenges of managing information for simulation including complex ‘big data’ types (e.g. point clouds). The research in this paper was carried out through an empirical approach to create a data-rich Building Information Model (BIM) under real world conditions. Real world measurements of environmental conditions were used to validate the effectiveness of simulations using commercial off-the-shelf (COTS) software packages. In addition, the practicalities of the integration of such data inside the BIM were investigated. Data capture using the methods described in this paper requires extraordinary effort and is expensive in both time and cost. However, advances in BIM enabling technologies such as Indoor Mobile Mapping (IMM) seek improved savings in data collection. Technological advances will further improve the integration of data capture and extraction of information used by simulation tools. Once complete it is envisaged that the GreenBIM model would be disseminated among a broad community of researchers to investigate various perspectives in a collaborative manner

Dissipative Chaos in Semiconductor Superlattices

We consider the motion of ballistic electrons in a miniband of a semiconductor superlattice (SSL) under the influence of an external, time-periodic electric field. We use the semi-classical balance-equation approach which incorporates elastic and inelastic scattering (as dissipation) and the self-consistent field generated by the electron motion. The coupling of electrons in the miniband to the self-consistent field produces a cooperative nonlinear oscillatory mode which, when interacting with the oscillatory external field and the intrinsic Bloch-type oscillatory mode, can lead to complicated dynamics, including dissipative chaos. For a range of values of the dissipation parameters we determine the regions in the amplitude-frequency plane of the external field in which chaos can occur. Our results suggest that for terahertz external fields of the amplitudes achieved by present-day free electron lasers, chaos may be observable in SSLs. We clarify the nature of this novel nonlinear dynamics in the superlattice-external field system by exploring analogies to the Dicke model of an ensemble of two-level atoms coupled with a resonant cavity field and to Josephson junctions.Comment: 33 pages, 8 figure

Информационные возможности сведений административного учёта о сделках с жилой недвижимостью для расчёта цен на российском рынке жилья

Purpose of the study. Development, justification and testing of a methodology for improving statistical monitoring of average prices in the Russian housing market, based on the use of registration information of the Unified State Register of Real Estate (USRN) on transactions for the purchase of residential real estate, in accordance with international statistical standards for Residential Property Price statistics.Materials and methods. The theoretical basis of the study was the United Nations system of national accounts (version of 2008), including the European system of accounts as amended in 2010. The research methodological base was made up of official statistical sources: metadata and international statistics guidelines in the field of national accounting, Handbook on Residential Property Price Indices and related housing indicators, as well as methodological provisions and an album of Rosstat forms, and methodological materials of the administrative statistics of the Federal Service for State Registration, Cadastre and Cartography of the Russian Federation (Rosreestr). The depersonalized registration data on households’ market transactions of the Unified State Register of Property Rights and Transactions maintaining by Rosreestr were used as an information database of the research.Results. The main result of the study is the design and substantiation of a system of indicators for the construction of an integrated information source for Residential Property Price statistics, on the base on interdepartmental information interaction.Conclusion. The proposed system of indicators will provide a highquality database that could be used in order to construct constant quality House Prices for various types of homogeneous residential property in the housing market, complying with the concepts of international statistical standards.Цель исследования. Разработка, обоснование и апробация методики совершенствования статистического наблюдения за средними ценами на российском рынке жилья, на основе использования регистрационной информации о сделках по купле-продаже жилой недвижимости в Едином государственном реестре недвижимости (ЕГРН), в соответствии с международными учётными стандартами статистики цен на рынке жилой недвижимости.Материалы и методы. Теоретической основой исследования стала система национальных счетов ООН в редакции 2008 года, в том числе европейской системы счетов в редакции 2010 года. Методологическую базу исследования составили официальные статистические источники: метаданные и руководства международной статистики в области учёта и анализа цен на рынке жилой недвижимости, методологические положения и альбом форм Росстата, а также метаданные административной статистики Федеральной службы государственной регистрации, кадастра и картографии (Росреестра). В качестве информационной базы для проведения экспериментальных расчётов были использованы деперсонифицированные сведения Единого государственного реестра недвижимости и методологические материалы по его ведению.Результаты. Главным результатом выполненного исследования представляется конструирование и обоснование системы показателей для формирования интегрального информационного фонда статистики цен на рынке жилья, основанного на межведомственном информационном взаимодействии.Заключение. Предложенная система показателей обеспечит качественный, соответствующий требованиям международных стандартов расчёт средних цен квадратного метра общей площади квартир на рынке жилой недвижимости, в разрезе групп квартир, однородных по набору основных установленных для федерального статистического наблюдения признаков, на квартальной и годовой основе

Проблемы региональной идентификации потерь производства от пандемии COVID-19 и пути их решения в системе международных статистических стандартов

Purpose of research. Analysis of the information capabilities of the methodology of the UN national accounts system as amended in 2008 to solve the problems of regional identification of production losses from the COVID-19 pandemic. The coronavirus infection pandemic caused a decline in production in almost all types of economic activity. The Russian government has identified a strategy to counter the extraordinary economic crisis triggered by the pandemic. The range of addressees of anti-crisis measures of the executive branch in the sectors of producers is determined, at the federal and regional levels, according to the main type of activity declared during registration, in accordance with the approved list of codes of the Russian National Classifier of Types of Economic Activity for the types of activities that are most affected by the pandemic and self-isolation regime. The approved list of such types of activities over the past 2 months has been repeatedly adjusted by the Government of the Russian Federation, taking into account the recommendations of experts and proposals of business-structures, in order to ensure the highest efficiency and targeted state support for manufacturers. Ensuring targeted state support during optimization of the federal resources distribution between regions - is an urgent task that requires accurate regional identification of production losses from the COVID-19 pandemic. However, the solution of this problem is significantly difficult in relation to the activities of multi-regional producers - enterprises that carry out production simultaneously in several territories of the Russian Federation. This is due to the characteristics of the organization system of statistical accounting of resources and production results in the enterprise sector. The paper considers the possibility of assessing the gross value added at the regional level for the aggregate of local producing units, grouped by the type of economic activity, based on methodological principles harmonized with international standards and guidelines of the current version of the national and regional accounts system and provided with resources of official (state and administrative) statistics of the Russian Federation.Materials and methods. The research information base was made up of official statistical sources: metadata and international statistics guidelines in the field of subnational accounting, methodological provisions and an album of ROSSTAT forms, as well as methodological materials of administrative statistics of the Federal Tax Service (FTS) and the Social Insurance Fund. The methodological basis of the study was the United Nations system of national accounts as amended in 2008, including the European system of regional accounts as amended in 2010.Results. The paper analyzes the principles of the European system of regional accounts, which are useful to use in Russian statistics for adequate accounting of the activities’ results of multiregional enterprises at the place of actual production and methodological approaches to assessing the number of such enterprises and the results of their production at the subnational level are proposed. The results obtained will allow us to estimate the loss of multiregional enterprises of different types of activity from the decline in production as a result of the ban on interregional relations during the COVID-19 pandemic, in order to determine the recipients of state support for enterprises in the regions. In particular, the proposed indicator for reducing the regional GVA for the most affected by the quarantine measures activities can be used as a condition for the allocation of funds as part of overcoming the consequences of the pandemic. The application of the proposed methodology in calculating the gross value added at the place of actual production for the aggregate of geographically separate divisions of multiregional enterprises will increase the targeting and effectiveness of state support for enterprises and entrepreneurs affected by the consequences of the spread of coronavirus infection, and will optimize the distribution of federal resources between regions, which is a prerequisite for successful overcoming “coronacrisis”.Цель исследования. Анализ информационных возможностей методологии система национальных счетов ООН в редакции 2008 года для решения проблем региональной идентификации потерь производства от пандемии COVID-19. Пандемия коронавирусной инфекции вызвала спад производства практически во всех видах экономической деятельности. Правительство РФ определило стратегию противодействия текущему экономическому кризису, спровоцированному пандемией. Круг адресатов антикризисных мероприятий исполнительной власти в секторах производителей определяется и на федеральном, и на региональном уровне по заявленному при регистрации основному виду деятельности, в соответствии с утвержденным перечнем кодов ОКВЭД видов деятельности, наиболее пострадавших от пандемии и режима самоизоляции. Утверждённый перечень таких видов деятельности за последние 2 месяца неоднократно корректировался Правительством РФ, с учётом рекомендаций экспертов и предложений бизнес – структур, чтобы обеспечить наибольшую результативность и адресность государственной поддержки производителей. Обеспечение адресности государственной поддержки при оптимизации распределения между регионами федеральных ресурсов – это актуальная задача, которая требует точной региональной идентификации потерь производства от пандемии COVID-19. Однако решение этой задачи существенно затруднено в отношении деятельности мультирегиональных производителей – предприятий, которые осуществляют производство одновременно на нескольких территориях РФ. Это обусловлено особенностями организации система статистического учёта ресурсов и результатов производства в секторе предприятий. В работе рассматриваются возможности оценки валовой добавленной стоимости на региональном уровне для совокупности местных производящих единиц, сгруппированных по видам экономической деятельности, на основе методологических принципов, гармонизированных с международными стандартами и руководствами актуальной версии системы национальных и региональных счетов и обеспеченных ресурсами официальной (государственной и административной) статистики РФ.Материалы и методы. Информационную базу исследования составили официальные статистические источники: мета- данные и руководства международной статистики в области субнационального учёта, методологические положения и альбом форм Росстата, а также методологические материалы административной статистики Федеральной налоговой службы (ФНС) и Фонда социального страхования (ФСС). Методологической основой исследования стала система национальных счетов ООН в редакции 2008 года, в том числе европейской системы региональных счетов в редакции 2010 года.Результаты. В работе проанализированы принципы европейской системы региональных счетов, которые полезно использовать в российской статистике для адекватного учёта результатов деятельности мультирегиональных предприятий по месту фактического производства и предложены методологические подходы к оценке количества таких предприятий и результатов их производства на субнациональном уровне. Полученные результаты позволят адекватно оценить потери мультирегиональных предприятий разных видов деятельности от спада производства в результате запрета на межрегиональные связи в период пандемии COVID-19, с целью определения получателей государственной поддержки предприятий в регионах. В частности, предложенный показатель снижения региональной ВДС по наиболее пострадавшим от карантинных мер видам деятельности может использоваться в качестве условия при выделении фондов в рамках преодоления последствий пандемии. Применение предложенной методологии в расчётах валовой добавленной стоимости по месту фактического производства для совокупности территориально обособленных подразделений мультирегиональных предприятий повысит адресность и результативность государственной поддержки предприятий и предпринимателей, пострадавших от последствий распространения коронавирусной инфекции, и позволит оптимизировать распре- деление федеральных ресурсов между регионами, что является необходимым условием успешного преодоления «коронакризиса»

The conserved C-terminus of the PcrA/UvrD helicase interacts directly with RNA polymerase

Copyright: © 2013 Gwynn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by a Wellcome Trust project grant to MD (Reference: 077368), an ERC starting grant to MD (Acronym: SM-DNA-REPAIR) and a BBSRC project grant to PM, NS and MD (Reference: BB/I003142/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Oligomerization of the E. coli Core RNA Polymerase: Formation of (α2ββ'ω)2–DNA Complexes and Regulation of the Oligomerization by Auxiliary Subunits

In this work, using multiple, dissimilar physico-chemical techniques, we demonstrate that the Escherichia coli RNA polymerase core enzyme obtained through a classic purification procedure forms stable (α2ββ'ω)2 complexes in the presence or absence of short DNA probes. Multiple control experiments indicate that this self-association is unlikely to be mediated by RNA polymerase-associated non-protein molecules. We show that the formation of (α2ββ'ω)2 complexes is subject to regulation by known RNA polymerase interactors, such as the auxiliary SWI/SNF subunit of RNA polymerase RapA, as well as NusA and σ70. We also demonstrate that the separation of the core RNA polymerase and RNA polymerase holoenzyme species during Mono Q chromatography is likely due to oligomerization of the core enzyme. We have analyzed the oligomeric state of the polymerase in the presence or absence of DNA, an aspect that was missing from previous studies. Importantly, our work demonstrates that RNA polymerase oligomerization is compatible with DNA binding. Through in vitro transcription and in vivo experiments (utilizing a RapAR599/Q602 mutant lacking transcription-stimulatory function), we demonstrate that the formation of tandem (α2ββ'ω)2–DNA complexes is likely functionally significant and beneficial for the transcriptional activity of the polymerase. Taken together, our findings suggest a novel structural aspect of the E. coli elongation complex. We hypothesize that transcription by tandem RNA polymerase complexes initiated at hypothetical bidirectional “origins of transcription” may explain recurring switches of the direction of transcription in bacterial genomes