Noise studies of magnetization dynamics in dilute magnetic semiconductor heterostructures

We study theoretically and experimentally the frequency and temperature dependence of resistivity noise in semiconductor heterostructures delta-doped by Mn. The resistivity noise is observed to be non-monotonous as a function of frequency. As a function of temperature, the noise increases by two orders of magnitude for a resistivity increase of about 50%. We study two possible sources of resistivity noise -- dynamic spin fluctuations and charge fluctuations, and find that dynamic spin fluctuations are more relevant for the observed noise data. The frequency and temperature dependence of resistivity noise provide important information on the nature of the magnetic interactions. In particular, we show how noise measurements can help resolve a long standing debate on whether the Mn-doped GaAs is an p-d Zener/RKKY or double exchange ferromagnet. Our analysis includes the effect of different kinds of disorder such as spin-glass type of interactions and a site-dilution type of disorder. We find that the resistivity noise in these structures is well described by a disordered RKKY ferromagnet model dynamics with a conserved order parameter.Comment: 15 pages, 7 eps figures, published versio

ХИМИЯ И ФУНКЦИОНАЛЬНЫЕ МАТЕРИАЛЫ. НАУЧНАЯ ШКОЛА АКАДЕМИКА Ф. А. КУЗНЕЦОВА

The paper presents a wide range of problems associated with the formation, development and practical implementation of research in materials science, carried out under direct leadership of Academician F. A. Kuznetsov by the team of researchers from the Nikolaev Institute of Inorganic Chemistry SB RAS. It shows the fruitfulness of his ideas of complex physicochemical research into each stage of the preparation of material from the precursor to the finished specific device element. Attention is drawn to his accurate prediction of the importance of selectable objects of study, his ability to correlate ongoing research with urgent global issues such as electronics, computer science, energy and photovoltaics and his skill to rally the team with a common idea and encourage active participation in the development of science both in Russia and internationally while remaining the main driving force of conducted advanced work. The paper is written in the memory of the eminent person, organizer of science, scientist and patriot whose work has always been focused on breakthrough technologies that ensure the prosperity and security of the Motherland.Рассмотрен широкий круг проблем, связанных со становлением, развитием и практической реализацией научных исследований в области материаловедения, выполненных коллективом сотрудников Института неорганической химии им. А. В. Николаева СО РАН под руководством академика Ф. А. Кузнецова. Показана плодотворность его идеи комплексного физико-химического изучения каждой стадии приготовления материала: от предшественника к готовому элементу конкретного устройства. Отмечено его безошибочное предвидение значимости выбираемых объектов исследования, его умение связывать проводимые исследования с такими насущными и глобальными проблемами, как электроника, информатика, энергетика, фотовольтаика, а также его способность сплачивать коллектив общей идеей и активное участие в развитии как российской, так и международной науки, оставаясь при этом локомотивом проводимых передовых работ. Статья написана в память о человеке, организаторе науки, ученом и патриоте, чья деятельность всегда была нацелена на прорывные технологии, обеспечивающие процветание и безопасность Родины

Protestant women in the late Soviet era: gender, authority, and dissent

At the peak of the anti-religious campaigns under Nikita Khrushchev, communist propaganda depicted women believers as either naïve dupes, tricked by the clergy, or as depraved fanatics; the Protestant “sektantka” (female sectarian) was a particularly prominent folk-devil. In fact, as this article shows, women’s position within Protestant communities was far more complex than either of these mythical figures would have one believe. The authors explore four important, but contested, female roles: women as leaders of worship, particularly in remote congregations where female believers vastly outnumbered their male counterparts; women as unofficial prophetesses, primarily within Pentecostal groups; women as mothers, replenishing congregations through high birth rates and commitment to their children’s religious upbringing; and women as political actors in the defence of religious rights. Using a wide range of sources, which include reports written by state officials, articles in the church journal, letters from church members to their ecclesiastical leaders in Moscow, samizdat texts, and oral history accounts, the authors probe women’s relationship with authority, in terms of both the authority of the (male) ministry within the church, and the authority of the Soviet state

Генетическая характеристика больных муковисцидозом в Российской Федерации по данным Национального регистра (2014)

The aim of this study was to investigate genetic features of patients with cystic fibrosis (CF) according to the National Register findings in Russia. Methods. The study involved 2,131 CF patients living in 74 regions of Russia who were included in the National Register of CF patients in 2014. Results. Genetic testing was performed in 89% of patients. The total mutant allele frequency was 81.2%. One hundred and twenty two mutations were found which comprised 173 genotypes; «mild» mutations took 23%. The most common mutant allele frequencies in the descending order were as follows: F508del, 51.53%; СFTRdele2,3, 5.93%; E92K, 2.62%; 3849+10kbC>T, 2.14%; 2184insA, 1.80%; W1282X, 1.80%; 2143delT, 1.69 %; N1303K, 1.43%; G542X, 1.16%; 1677delTA, 0.98%; L138ins, 0.95%; R334W, 0.85%; 394delTT, 0.85%; 3821delT, 0.42%; 2789+5G>A, 0.37%; S466X, 0.37%; S1196X, 0.37%; 3272-16T>A, 0.34%; W1282R, 0.29%; 3944delGT, 0.21%. Typical features of CFTR mutation distribution in Russian CF patients were lower frequency of mutations which are predominant worldwide, such as F508del, G542X, N1303K, and scarce G551D, 1717-1G>A, 2183AA>G mutations. On contrary, СFTRdele2,3, E92K, 2184insA, 2143delT, 1677delTA, L138ins mutations which are quite rare in Western Europe were encountered more often in Russia. «Mild» mutations were more common in Russian population of CF patients compared to European countries and have being increasing last years. Conclusion. Genetic features of Russian CF patients could be provided by Slavic, Turkic and Finno-Ugric genetic influence on Russian population.Генетическому разнообразию больных муковисцидозом (МВ) в России посвящены единичные работы на ограниченной выборке больных. Цель. Выявление особенностей генетического профиля больных МВ в России по данным Национального регистра (2014). Материалы и методы. Данные пациентов с МВ (n = 2 131) из 74 регионов России, включенные в Национальный регистр больных МВ (2014). Результаты. Генетическое обследование проведено у 89,0 % больных, суммарная аллельная частота выявленных мутаций составила 81,2 %. Выявлено 122 мутации, которые сформировали 173 различных генотипа, среди которых доля «мягких» генотипов составила 23,0 %. Аллельная частота самых распространенных мутаций представлена в порядке убывания: F508del – 51,53 %, СFTRdele2,3 – 5,93 %, E92K – 2,62 %, 3849+10kbC>T – 2,14 %, 2184insA – 1,80 %, W1282X – 1,80 %, 2143delT – 1,69 %, N1303K – 1,43 %, G542X – 1,16 %, 1677delTA – 0,98 %, L138ins – 0,95 %, R334W – 0,85 %, 394delTT – 0,85 %, 3821delT – 0,42 %, 2789+5G>A – 0,37 %, S466X – 0,37 %, S1196X – 0,37 %, 3272-16T>A – 0,34 %, W1282R – 0,29 %, 3944delGT – 0,21 %. Выявлено, что особенностями распределения мутаций. CFTRсреди российских больных МВ являются меньшая частота доминирующих в мире мутаций, таких как F508del, G542X, N1303K, единичная встречаемость мутаций G551D, 1717-1G>A, 2183AA>G и наоборот – более высокая частота мутаций, являющихся относительно редкими в западноевропейских странах: СFTRdele2,3, E92K, 2184insA, 2143delT, 1677delTA, L138ins. Другой особенностью является более высокая встречаемость «мягких» мутаций в России по сравнению со странами Европы. Выявлено, что доля «мягких» мутаций в популяции больных МВ на протяжении последних лет увеличивается. Заключение. При формировании населения России особенности генетического профиля российских больных МВ определяются славянскими, тюркскими и финно-угорскими влияниями