All-In-One Robust Estimator of the Gaussian Mean

The goal of this paper is to show that a single robust estimator of the mean of a multivariate Gaussian distribution can enjoy five desirable properties. First, it is computationally tractable in the sense that it can be computed in a time which is at most polynomial in dimension, sample size and the logarithm of the inverse of the contamination rate. Second, it is equivariant by translations, uniform scaling and orthogonal transformations. Third, it has a high breakdown point equal to $0.5$, and a nearly-minimax-rate-breakdown point approximately equal to $0.28$. Fourth, it is minimax rate optimal, up to a logarithmic factor, when data consists of independent observations corrupted by adversarially chosen outliers. Fifth, it is asymptotically efficient when the rate of contamination tends to zero. The estimator is obtained by an iterative reweighting approach. Each sample point is assigned a weight that is iteratively updated by solving a convex optimization problem. We also establish a dimension-free non-asymptotic risk bound for the expected error of the proposed estimator. It is the first result of this kind in the literature and involves only the effective rank of the covariance matrix. Finally, we show that the obtained results can be extended to sub-Gaussian distributions, as well as to the cases of unknown rate of contamination or unknown covariance matrix.Comment: 41 pages, 5 figures; added sub-Gaussian case with unknown Sigma or ep

Sex-Specific Effects of a Wartime-Like Radiation Exposure on Cognitive Function.

Evaluating the risk for central nervous system (CNS) effects after whole-body or partial-body irradiation presents challenges due in part to the varied exposure scenarios in the context of occupational, accidental or wartime releases. Risk estimations are further complicated by the fact that robust changes in brain function are unlikely to manifest until significantly late post exposure times. Collectively, the current data regarding CNS radiation risk are conflicting in humans and a survey of the animal model data shows that it is similarly inconsistent. Due to the sparseness of such data, the current study was conducted using male and female mice to evaluate the brain for the delayed effects of a 2 Gy whole-body exposure to c rays starting six months postirradiation. Behavioral testing indicated sex-specific differences in the induction of anxiety-like behaviors and in the ability to abolish fear memories. Molecular analyses showed alterations in post-synaptic protein levels that might affect synaptic plasticity and increased levels of global DNA methylation, suggesting a potential epigenetic mechanism that might contribute to radiation-induced cognitive dysfunction. These data add to the understanding of the CNS response to whole-body irradiation and may lead to improved risk assessment and provide guidance in the development of effective radiation countermeasures to protect military personnel and civilians alike

Physiological aspects of educational training adaptation of students

20 healthy male and female students of Artsakh State University aged 18-20 years have participated in an experiment to study the mechanisms of training adaptation. Surveys were conducted during the academic semester in 2 stages: the non-examination period (March-April) - Monday and Friday, before and after school and during the examination period (May-June) - before and after the exam. In order to study the impact of mental stress a survey was also conducted among students once they complete mental or intellectual Eysenck test. A psychological testing of students was carried out to identify the level of intelligence (IQ) by Eysenck, personal and situational anxiety by Spielberger and health, activity, mood by SAN (HAM) questionnaire. Basic hemodynamic parameters were measured: heart rate, systolic and diastolic blood pressure. ECG examination was conducted using R.M. Baevsky's cardio-ervalography method. Comparative analysis of the dynamics of the studied parameters showed that the process of adaptation of students to the teaching load is accompanied by periods of decline during non-examination period, more vividly expressed when doing mental or intellectual work, and tension of the studied parameters during the examination period

Potencial parlamentario para garantizar la seguridad del Estado: experiencia constitucional de los países de la era postsoviética

The article presents the author’s analysis of the constitutional acts of the countries of the post-Soviet space in order to consolidate in them the catalog of powers of parliaments in the field of state security. The study revealed two constitutional approaches reflecting the catalog of powers of parliaments in ensuring the security of the state: the parliament acts as a body with the prerogative of introducing exclusive regimes in the state, declaring war and concluding peace; the parliament acts as a body that legalizes decrees of the head of state or government on security issues.El artículo presenta el análisis del autor de los actos constitucionales de los países del espacio postsoviético para consolidar en ellos el catálogo de poderes de los parlamentos en el campo de la seguridad del estado. El estudio reveló dos enfoques constitucionales que reflejan el catálogo de poderes de los parlamentos para garantizar la seguridad del estado: el actúa como un órgano con la prerrogativa de introducir regímenes exclusivos en el estado, declarar la guerra y concluir la paz; el parlamento actúa como un organismo que legaliza los decretos del jefe de estado o gobierno sobre cuestiones de seguridad

Ampk regulates IgD expression but not energy stress with B cell activation.

Ampk is an energy gatekeeper that responds to decreases in ATP by inhibiting energy-consuming anabolic processes and promoting energy-generating catabolic processes. Recently, we showed that Lkb1, an understudied kinase in B lymphocytes and a major upstream kinase for Ampk, had critical and unexpected roles in activating naïve B cells and in germinal center formation. Therefore, we examined whether Lkb1 activities during B cell activation depend on Ampk and report surprising Ampk activation with in vitro B cell stimulation in the absence of energy stress, coupled to rapid biomass accumulation. Despite Ampk activation and a controlling role for Lkb1 in B cell activation, Ampk knockout did not significantly affect B cell activation, differentiation, nutrient dynamics, gene expression, or humoral immune responses. Instead, Ampk loss specifically repressed the transcriptional expression of IgD and its regulator, Zfp318. Results also reveal that early activation of Ampk by phenformin treatment impairs germinal center formation but does not significantly alter antibody responses. Combined, the data show an unexpectedly specific role for Ampk in the regulation of IgD expression during B cell activation

Self-Organising Systems in the Context of Academic Environment

Introduction. In the era of globalisation, which affects all spheres of modern social life (political, financial, scientific, technical, religious, cultural), the processes of internationalisation and academic migration in higher education have significantly intensified. The rapidly growing mobility in higher education, when students study outside their country of residence, is accompanied by certain problems, which include students’ adaptation to the conditions of unfamiliar urban environment. The introduction of new methodological tools for teaching humanitarian disciplines in universities can contribute to the elimination of barriers and successful transition of students to another, different from their customary, socio-cultural environment. The aim of the research was to present the results of experimental work aimed at the development of students’ intercultural communicative tolerance within the foreign language learning, and to reveal the role of self-organising systems in the university international academic environment. Methodology and research methods. The study is based on the theory of self-organising systems. In the process of designing and application of the authors’ technology aimed at developing students’ intercultural communicative tolerance, experimental methods and the method of comparative analysis were used. Results and scientific novelty. It has been shown that academic migration is a self-organising system characterised by socio-cultural instability. The factors of human transition from one urboecological niche to another, which often disturbs the balance of social systems, have been described. Lacking knowledge about such processes in the theory and practice of pedagogy within higher education has been stated. Insufficient level of intercultural communicative tolerance of Russian (132 people) and foreign (40 people) students, who studied at the Ural Federal University (Ekaterinburg, Russia) in 2015, has proved the necessity of its systematic focused formation. The technology for the development of this type of tolerance within the framework of the ‘Foreign Language’ discipline has been proposed. The approbation of the technology has demonstrated its effectiveness. The students have not only acquired the necessary competencies, but also learned to adapt to the new academic environment, as well as had the opportunity to directly participate in the creation of their own academic programs. Practical significance. The research confirms the productivity of mutual adaptation of students to an unfamiliar socio-cultural academic environment. The author’s technology of intercultural communicative tolerance development can be used to optimise the pedagogical conditions of maintaining the processes of internationalisation and academic mobility within universities.Введение. В эпоху глобализации, затрагивающей все сферы жизнедеятельности в современном обществе: политическую, финансовую, научно-техническую, религиозную, культурную, в высшей школе заметно активизировались процессы интернационализации и академической миграции. Быстрые темпы роста мобильности высшего образования, когда студенты осваивают программы профессиональной подготовки за пределами страны, гражданами которой они являются, сопровождаются определенными проблемами, в том числе связанными с адаптацией обучающихся к условиям мало знакомой урбоэкологической среды. Устранению барьеров для успешного перехода студентов в иное, отличающееся от привычного социокультурное пространство может способствовать внедрение в вузовскую практику нового методического инструментария преподавания гуманитарных дисциплин. Цели публикации – представить результаты экспериментальной работы, направленной на развитие межкультурной коммуникативной толерантности студентов на занятиях по иностранному языку, и раскрыть роль самоорганизующихся систем в университетской международной образовательной среде. Методология и методики. Исследование осуществлялось с опорой на ключевые положения теории самоорганизующихся систем. При создании и апробации авторской технологии иноязычного обучения применялись опытно-экспериментальные методы и метод сравнительного анализа. Результаты и научная новизна. Показано, что академическая миграция является самоорганизующейся системой, характеризующейся социокультурной нестабильностью. Описаны факторы перемещения человека из одной урбоэкологической ниши в другую, которое нередко нарушает равновесие социальных систем. Констатируется малый объем информации о данных процессах в теории и практике педагогики высшей школы. Установленный в ходе мониторинга недостаточный уровень межкультурной коммуникативной толерантности у российских (132 человека) и иностранных (40 человек) студентов, обучающихся в Уральском федеральном университете (г. Екатеринбург, Россия) в 2015 году, убеждает в необходимости ее планомерного целенаправленного формирования. Предложена технология поступательного развития этого вида толерантности в рамках курса иностранного языка в вузе. Апробация технологии продемонстрировала ее эффективность. Студенты не только приобрели требующиеся компетенции, но и научились самостоятельно приспосабливаться к новой академической обстановке, а также получили возможность непосредственно участвовать в разработке собственных индивидуальных программ обучения. Практическая значимость. Проведенное исследование подтверждает продуктивность взаимоадаптации студентов, попадающих в незнакомое социокультурное образовательное пространство. Авторская технология развития межкультурной коммуникативной толерантности может использоваться для оптимизации педагогических условий сопровождения процессов интернационализации университетов и академической мобильности.the Russian Foundation for Basic Reserach №16–02–00164 “Scientific and Methodological Tools for Measuring, Assessing and Managing the Factors of Social and Economic Inequality in the System of Reproduction of the Labour Potential in Russian Regions”РФФИ, №16–02–00164 «Научно-методические инструментарии измерения, оценки и управления факторами социально-экономического неравенства в системе воспроизводства трудового потенциала регионов России

Applications of p-deficiency and p-largeness

We use Schlage-Puchta's concept of p-deficiency and Lackenby's property of p-largeness to show that a group having a finite presentation with p-deficiency greater than 1 is large, which implies that Schlage-Puchta's infinite finitely generated p-groups are not finitely presented. We also show that for all primes p at least 7, any group having a presentation of p-deficiency greater than 1 is Golod-Shafarevich, and has a finite index subgroup which is Golod-Shafarevich for the remaining primes. We also generalise a result of Grigorchuk on Coxeter groups to odd primes.Comment: 23 page

Meaningfulness of academic migrants’ education, its assessment and modeling on IT-based technologies

The article is devoted to the relevant problems of educational migration flows both in the real and virtual environment. The article discusses the positive and negative experience with virtual platforms in Russia and abroad. Particular attention is paid to the cultural and cognitive characteristics of the students belonging to the Generation Z, which requires the creation of entirely different instruments for implementing the educational process. The authors propose the method of creation, control and evaluation of feedback in the process of virtual educational migration using the latest IT-technologies that are utilized to create ultra-fast feedback and allow to bring new technologies into the learning process. In this scheme, the student is no longer a passive listener, but an active creator of new knowledge. The methodical research toolkit includes the mathematical, engineering, information methods of processing the results, including computer simulation. The testing of methodological tools was held at the University of Economics in Bratislava (Slovakia). These results confirm the possibility of the new method of providing feedback.This enable to improve the training quality of students, who are the members of the educational migration flows. Moreover, the training and examining may start at courses on adaptation, enabling to pre-determine the necessary competencies. In addition, it is cost-effective to limit the real presence of foreign lecturers at the host university to a certain minimum, followed by the support for virtual feedback. However, the use of IT-technologies is not a sufficient factor in improving the quality of education and the level of progress achieved by the trainees, but it can be a good helper in the course of the examination, automation of the selected methods of control, as it is a more individualized approach to learning

May Measurement Month 2017: an analysis of blood pressure screening results in Armenia-Europe

Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017. Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. The study was conducted in public areas (14 sites in Yerevan and 18 in regions), both indoor and outdoor, as well as in 42 primary care centres. A total of 9199 individuals were screened during MMM17 of which 9186 had three BP measurements available. The mean age of screened individuals was 50 ± 16.7 years, 57.3% was female. At the time of screening 17.9% were on antihypertensive medication. After imputation, a percentage of participants with hypertension was 33.9%, and 52.9% of them were on treatment. Of those treated, 77.0% had uncontrolled BP. MMM17 was the largest BP screening campaign undertaken in Armenia. We found that in Armenia, untreated hypertension is common, as is not adequately treated hypertension