Extended and revised archaeomagnetic database and secular variation curves from Bulgaria for the last eight millennia

International audienceThe efforts of geophysicists to describe geomagnetic field behaviour in the past lead to creation of different geomagnetic field models. On the other hand, the established regional palaeosecular variations of geomagnetic elements are increasingly used for dating purposes in archaeology. Both of these goals can be achieved if sufficient amounts of long archaeomagnetic data sets exist for different geographical regions. The accumulation of archaeomagnetic determinations began at the middle of the last century, parallel with the progressive development of experimental methodology and acceptance criteria. The presence of great number of old determinations requires their critical assessment. The important question about the reliability of the associated dating intervals should be also re-assessed. All this requires the continuous refinement and extension of the accumulated databases. This paper presents the last synthesis of Bulgarian archaeomagnetic database and the local palaeosecular variation curves obtained using a statistical treatment based on Bayesian approach (RenCurve software). The rock-magnetic characteristics of the newly included, non-published results are summarized

Viscoelastic properties of cell walls of single living plant cells determined by dynamic nanoindentation

Plant development results from controlled cell divisions, structural modifications, and reorganizations of the cell wall. Thereby, regulation of cell wall behaviour takes place at multiple length scales involving compositional and architectural aspects in addition to various developmental and/or environmental factors. The physical properties of the primary wall are largely determined by the nature of the complex polymer network, which exhibits time-dependent behaviour representative of viscoelastic materials. Here, a dynamic nanoindentation technique is used to measure the time-dependent response and the viscoelastic behaviour of the cell wall in single living cells at a micron or sub-micron scale. With this approach, significant changes in storage (stiffness) and loss (loss of energy) moduli are captured among the tested cells. The results reveal hitherto unknown differences in the viscoelastic parameters of the walls of same-age similarly positioned cells of the Arabidopsis ecotypes (Col 0 and Ws 2). The technique is also shown to be sensitive enough to detect changes in cell wall properties in cells deficient in the activity of the chromatin modifier ATX1. Extensive computational modelling of the experimental measurements (i.e. modelling the cell as a viscoelastic pressure vessel) is used to analyse the influence of the wall thickness, as well as the turgor pressure, at the positions of our measurements. By combining the nanoDMA technique with finite element simulations quantifiable measurements of the viscoelastic properties of plant cell walls are achieved. Such techniques are expected to find broader applications in quantifying the influence of genetic, biological, and environmental factors on the nanoscale mechanical properties of the cell wall

Отраслевая статистика в условиях трансформации сети общедоступных библиотек: проблемы и решения

There are described the problems of state statistics in the field of library activities and the main trends in transformation of the network of public libraries of the Russian Federation. There is proposed an innovative approach to organizing the statistical reporting of the libraries.Освещены проблемы государственной статистики в библиотечной сфере деятельности и основные тенденции трансформации сети общедоступных библиотек Российской Федерации. Предложен инновационный подход к организации статистической отчетности библиотек

Combined XPS and contact angle studies of ethylene vinyl acetate and polyvinyl acetate blends

Cataloged from PDF version of article.In this study, we prepared thin films by blending ethylene vinyl acetate copolymers (EVA) containing 12-33 (wt.%) vinyl acetate (VA) with polyvinyl acetate (PVAc) and high density polyethylene homopolymers. Large area micropatterns having controlled protrusion sizes were obtained by phase-separation especially for the PVAc/EVA-33 blends using dip coating. These surfaces were characterized by XPS and contact angle measurements. A reasonably linear relation was found between the VA content on the surface (wt.%) obtained from XPS analysis and the VA content in bulk especially for PVAc/EVA-33 blend surfaces. PE segments were more enriched on the surface than that of the bulk for pure EVA copolymer surfaces similar to previous reports and VA enrichment was found on the EVA/HDPE blend surfaces due to high molecular weight of HDPE. Water theta(e) decreased with the increase in the VA content on the blend surface due to the polarity of VA. A good agreement was obtained between gamma(-)(s) and atomic oxygen surface concentration with the increase of VA content. The applicability of Cassie-Baxter equation was tested and found that it gave consistent results with the experimental water contact angles for the case where VA content was lower than 55 wt.% in the bulk composition. (C) 2011 Elsevier B. V. All rights reserved

Transient and asymmetric dust structures in the TeV-bright nova RS Oph revealed by spectropolarimetry

A long-standing question related to nova eruptions is how these eruptions can lead to the formation of dust despite the ostensibly inhospitable environment for dust within the hot, irradiated ejecta. Novae in systems such as the symbiotic binary RS Oph offers a articularly clear view of some nova shocks and any associated dust production. Here we use spectropolarimetric monitoring of the RS Oph starting two days after its eruption in 2021 Aug. to show that: dust was present in the RS Oph system as early as two days into the 2021 eruption; the spatial distribution of this early dust was asymmetric, with components both aligned with and perpendicular to the orbital plane of the binary; between two and nine days after the start of the eruption, this early dust was gradually destroyed; and dust was again created, aligned roughly with the orbital plane of the binary, more than 80 days after the start of the outburst, most likely as a result of shocks that arose as the ejecta interacted with circumbinary material concentrated in the orbital plane. Modelling of X-rays and very-high energy GeV and TeV emission from RS Oph days to months into the 2021 eruption suggests that collisions between the ejecta and the circumbinary material may have led to shock formation in two regions: the polar - perpendicular to the orbital plane where collimated outflows have been observed after prior eruptions, and a circumbinary torus in the orbital plane. The observations described here indicate that dust formed in approximately the same two regions, supporting the connection between shocks and dust in novae and revealing a very early onset of asymmetry. The spectropolarimetric signatures of RS Oph in the first week into the 2021 outburst indicate: polarized flux across the H{\alpha} emission line and position angle orientation relative to the radio axis are similar to the spectropolarimetric signatures of AGNs.Comment: 9 pages, 10 figures, 1 table, resubmitted to the Astronomy & Astrophysics after the first reviewer's repor

Magneto-Optical and Multiferroic Properties of Transition-Metal (Fe, Co, or Ni)-Doped ZnO Layers Deposited by ALD

ZnO doped with transition metals (Co, Fe, or Ni) that have non-compensated electron spins attracts particular interest as it can induce various magnetic phenomena and behaviors. The advanced atomic layer deposition (ALD) technique makes it possible to obtain very thin layers of doped ZnO with controllable thicknesses and compositions that are compatible with the main microelectronic technologies, which further boosts the interest. The present study provides an extended analysis of the magneto optical MO Kerr effect and the dielectric properties of (Co, Fe, or Ni)-doped ZnO films prepared by ALD. The structural, magneto optical, and dielectric properties were considered in relation to the technological details of the ALD process and the corresponding dopant effects. All doped samples show a strong MO Kerr behavior with a substantial magnetization response and very high values of the Kerr polarization angle, especially in the case of ZnO/Fe. In addition, the results give evidence that Fe-doped ZnO also demonstrates a ferroelectric behavior. In this context, the observed rich and versatile physical nature and functionality open up new prospects for the application of these nanostructured materials in advanced electronic, spintronic, and optical devices

An RNA Polymerase III-Dependent Heterochromatin Barrier at Fission Yeast Centromere 1

Heterochromatin formation involves the nucleation and spreading of structural and epigenetic features along the chromatin fiber. Chromatin barriers and associated proteins counteract the spreading of heterochromatin, thereby restricting it to specific regions of the genome. We have performed gene expression studies and chromatin immunoprecipitation on strains in which native centromere sequences have been mutated to study the mechanism by which a tRNAAlanine gene barrier (cen1 tDNAAla) blocks the spread of pericentromeric heterochromatin at the centromere of chromosome 1 (cen1) in the fission yeast, Schizosaccharomyces pombe. Within the centromere, barrier activity is a general property of tDNAs and, unlike previously characterized barriers, requires the association of both transcription factor IIIC and RNA Polymerase III. Although the cen1 tDNAAla gene is actively transcribed, barrier activity is independent of transcriptional orientation. These findings provide experimental evidence for the involvement of a fully assembled RNA polymerase III transcription complex in defining independent structural and functional domains at a eukaryotic centromere

Reforming sanitary-epidemiological service in Central and Eastern Europe and the former Soviet Union: an exploratory study

<p>Abstract</p> <p>Background</p> <p>Public health services in the Soviet Union and its satellite states in Central and Eastern Europe were delivered through centrally planned and managed networks of sanitary-epidemiological (san-epid) facilities. Many countries sought to reform this service following the political transition in the 1990s. In this paper we describe the major themes within these reforms.</p> <p>Methods</p> <p>A review of literature was conducted. A conceptual framework was developed to guide the review, which focused on the two traditional core public health functions of the san-epid system: communicable disease surveillance, prevention and control and environmental health. The review included twenty-two former communist countries in the former Soviet Union (fSU) and in Central and Eastern Europe (CEE).</p> <p>Results</p> <p>The countries studied fall into two broad groups. Reforms were more extensive in the CEE countries than in the fSU. The CEE countries have moved away from the former centrally managed san-epid system, adopting a variety of models of decentralization. The reformed systems remain mainly funded centrally level, but in some countries there are contributions by local government. In almost all countries, epidemiological surveillance and environmental monitoring remained together under a single organizational umbrella but in a few responsibilities for environmental health have been divided among different ministries.</p> <p>Conclusions</p> <p>Progress in reform of public health services has varied considerably. There is considerable scope to learn from the differing experiences but also a need for rigorous evaluation of how public health functions are provided.</p

The methodological basis of the functioning of the concept of “academic integrity” in Ukraine: administrative and legal analysis

Куліш, А. М. «Академічна доброчесність» в Україні: місце в освітньому процесі та законодовче регулювання / Куліш Анатолій Миколайович, Дуліба Євгенія Володимирівна, Миргород-Карпова Валерія Валеріївна, Аврамова Ольга Євгенівна // Наукові записки [Центральноукр. держ. пед. ун-ту імені Володимира Винниченка]. Сер.: Право. – 2022. – Вип. 12. – С. 258-265. - DOI: https://doi.org/10.36550/2522-9230-2022-12-258-265.Розглянуто основи утворення академічної доброчесності на міжнародній арені та в національному просторі. Вказано, що освітній процес є динамічним, оскільки наповнений постійними реформами, модернізаціями, удосконаленнями, а також вступом нових талановитих і здібних студентів. Разом із нововведеннями щодо освітнього процесу з’являються нові виклики та проблеми в отриманні якісної освіти. Все більше студентів знецінюють важливість якості освіти та використовують механізми для полегшення виконання наукових робіт. Такі механізми у національному законодавстві визначаються як «академічна недоброчесність». Розглянуто особливості впровадження академічної доброчесності у XX столітті та проаналізовано основоположні поняття у цій сфері. Акцентовано увагу на проблемах та передумовах порушення доброчесності студентами. За результатами опитування, встановлено, що вмотивованість викладача дуже впливає на бажання студентів навчатись. А завищений обсяг наукових робіт, та вимоги, які не відповідають інтелектуальному рівню відповідно до року навчання, спонукає використовувати плагіат. Наголошено, що освітні заклади повинні контролювати це питання. Також необхідно донести до студентів ту думку, що у випадку недотримання принципів академічної доброчесності розвиток науки постає під загрозою, адже саме молоді вчені є каталізатором змін.The article is devoted to the foundations of the formation of academic integrity in the international arena and in the national space. It is indicated that education is a priority for any modern state, because the future of Ukraine depends on the graduates of educational institutions. The educational process is dynamic, as it is filled with constant reforms, modernizations, improvements, as well as the admission of new talented and capable students. Along with innovations in the educational process, new challenges and problems in obtaining quality education appear. More and more students underestimate the importance of quality education and use mechanisms to facilitate the performance of scientific works. The article emphasizes that such mechanisms are defined as "academic dishonesty" in national legislation. The peculiarities of the implementation of academic integrity in the 20th century were considered and the fundamental concepts in this field were analyzed. Attention is focused on the problems and prerequisites of violation of integrity by students. In the article, special attention is paid to the question of the prerequisites for the students' desire not to observe the rules of academic integrity. A survey was conducted among students regarding the causes of academic dishonesty. As a result, it was established that the teacher's motivation greatly affects the students' desire to learn. Also, according to the results of the survey, it was determined that the inflated volume of scientific works, and requirements that do not correspond to the intellectual level according to the year of study, encourages the use of plagiarism. It was concluded that educational institutions should control this issue. It is also necessary to convey to students the idea that in case of non-compliance with the principles of academic integrity, the development of science is in danger, because it is young scientists who are the catalyst for change.Рассмотрены основы образования академической добродетели на международной арене и в национальном пространстве. Указано, что образовательный процесс динамичен, поскольку наполнен постоянными реформами, модернизациями, усовершенствованиями, а также вступлением новых талантливых и способных студентов. Вместе с новшествами в образовательном процессе появляются новые вызовы и проблемы в получении качественного образования. Все большее количество студентов обесценивают важность качества образования и используют механизмы для облегчения выполнения научных работ. Такие механизмы в национальном законодательстве определяются как академическая недоброчестность. Рассмотрены особенности внедрения академической добродетели в XX веке и проанализированы основополагающие понятия в этой сфере. Акцентировано внимание на проблемах и предпосылках нарушения добродетели студентами. По результатам опроса установлено, что мотивированность преподавателя оказывает большое влияние на желание студентов учиться. А завышенный объем научных работ и требования, не отвечающие интеллектуальному уровню в соответствии с годом обучения, побуждает использовать плагиат. Отмечено, что образовательные учреждения должны контролировать этот вопрос. Также необходимо донести до студентов то мнение, что в случае несоблюдения принципов академической добродетели, развитие науки возникает под угрозой, ведь именно молодые ученые являются катализатором изменений