bluuebunny/crossref_metadata_2025 huggingface dataset:
KỸ NGHỆ SƠ KỲ ĐÁ CŨ AN KHÊ TRONG BỐI CẢNH TIỀN SỬ VIỆT NAM
Authors: Sử Nguyễn Khắc
Published: September 2021

Bài báo này đã hệ thống hóa tư liệu điều tra, thám sát và khai quật ở các địa điểm Đá cũ vùng An Khê, tỉnh Gia Lai; xác định đặc trưng cơ bản của kỹ nghệ An Khê với phức hợp kỹ thuật công cụ: Chopper- Choping tool/Mũi nhọn (Piks) hình khối tam diện/Bifaces - Handaxes. Trong đó, chopper-choping chủ yếu ở khu vực châu Á, bifaces - handaxes nổi trội cho Đá cũ phương Tây và công cụ hình khối tam diện là nét riêng cho Đá cũ sớm vùng An Khê (Việt Nam). Kỹ nghệ An Khê khác và cổ hơn các kỹ nghệ sơ kỳ Đá cũ hiện biết ở Việt Nam, như Núi Đọ (Thanh Hóa) và Xuân Lộc (Đồng Nai). Kỹ nghệ An Khê cũng khác với kỹ nghệ Acheulean điển hình của châu Âu ở kỹ nghệ biface/rìu tay, nhưng có nhiều nét tương đương với kỹ nghệ Bách Sắc ở Quảng Tây (Trung Quốc) về chất liệu, kích thước, loại hình và kỹ thuật chế tác công cụ. Kỹ nghệ An Khê có niên đại từ 700,000 đến 900,000 BP. Phát hiện kỹ nghệ An Khê đã cung cấp cho chúng ta nhiều tư liệu mới, làm thay đổi một số nhận thức về lịch sử văn hóa giai đoạn cổ xưa nhất của nhân loại nói chung và Việt Nam nói riêng. Đó là ranh giới phân chia 2 kỹ nghệ biface và chopper (Movius line) ở cựu lục địa, con đường hình thành các kỹ nghệ sơ kỳ Đá cũ Đông Nam Á, tri thức của Người đứng thẳng (Homo erectus) trong quá trình thích ứng với môi trường cụ thể và vấn đề thời điểm mở đầu cho lịch sử Việt Nam.
VẤN ĐỀ NỮ QUYỀN TRONG TRUYỆN DÂN GIAN NGƯỜI VIỆT
Authors: Dương Đặng Quốc Minh , Lý Trần Thị
Published: September 2021

Vấn đề nữ quyền là một trong những lĩnh vực nghiên cứu đầy thú vị, được nhiều nhà nghiên cứu quan tâm. Ở Việt Nam, từ trước đến này đã có nhiều bài viết nghiên cứu về vấn đề nữ quyền trong văn học trung đại, trong văn học giai đoạn 1930 – 1945, nhất là trong văn học từ năm 2000 đến nay. Tìm hiểu văn học dân gian – cách riêng là các thể loại thần thoại, truyền thuyết và truyện cổ tích chúng tôi nhận thấy rằng ý thức nữ quyền đã manh nha hình thành. Qua việc xây dựng các hình ảnh của các nữ thần - nhân vật nữ, dân gian đã ghi nhận những đóng góp, những công trạng của nữ giới; qua đây dân gian cũng gửi gắm những mơ ước về một xã hội công bằng, bình đẳng - ở đó các quyền tự do yêu thương, quyền được giáo dục, quyền được tham gia các sinh hoạt xã hội được tái xác lập. Những “manh nha” này đã được văn học trung đại tiếp nhận và tiếp tục nâng cao trong văn học các giai đoạn sau.
MouseView.js: Reliable and valid attention tracking in web-based experiments using a cursor-directed aperture
Authors: Anwyl-Irvine Alexander L. , Armstrong Thomas , Dalmaijer Edwin S.
Published: September 2021

Psychological research is increasingly moving online, where web-based studies allow for data collection at scale. Behavioural researchers are well supported by existing tools for participant recruitment, and for building and running experiments with decent timing. However, not all techniques are portable to the Internet: While eye tracking works in tightly controlled lab conditions, webcam-based eye tracking suffers from high attrition and poorer quality due to basic limitations like webcam availability, poor image quality, and reflections on glasses and the cornea. Here we present MouseView.js, an alternative to eye tracking that can be employed in web-based research. Inspired by the visual system, MouseView.js blurs the display to mimic peripheral vision, but allows participants to move a sharp aperture that is roughly the size of the fovea. Like eye gaze, the aperture can be directed to fixate on stimuli of interest. We validated MouseView.js in an online replication (N = 165) of an established free viewing task (N = 83 existing eye-tracking datasets), and in an in-lab direct comparison with eye tracking in the same participants (﻿N = 50). Mouseview.js proved as reliable as gaze, and produced the same pattern of dwell time results. In addition, dwell time differences from MouseView.js and from eye tracking correlated highly, and related to self-report measures in similar ways. The tool is open-source, implemented in JavaScript, and usable as a standalone library, or within Gorilla, jsPsych, and PsychoJS. In sum, MouseView.js is a freely available instrument for attention-tracking that is both reliable and valid, and that can replace eye tracking in certain web-based psychological experiments.
In-depth characterization of self-healing polymers based on π–π nteractions
Authors: Meurer Josefine , Hniopek Julian , Ahner Johannes , Schmitt Michael , Popp Jürgen , Zechel Stefan , Peneva Kalina , Hager Martin D
Published: September 2021

The self-healing behavior of two supramolecular polymers based on π–π-interactions featuring different polymer backbones is presented. For this purpose, these polymers were synthesized utilizing a polycondensation of a perylene tetracarboxylic dianhydride with polyether-based diamines and the resulting materials were investigated using various analytical techniques. Thus, the molecular structure of the polymers could be correlated with the ability for self-healing. Moreover, the mechanical behavior was studied using rheology. The activation of the supramolecular interactions results in a breaking of these noncovalent bonds, which was investigated using IR spectroscopy, leading to a sufficient increase in mobility and, finally, a healing of the mechanical damage. This scratch-healing behavior was also quantified in detail using an indenter.
Nano-scale friction and wear of polymer coated with graphene
Authors: Vacher Robin S , de Wijn Astrid S
Published: September 2021

Background: Friction and wear of polymers at the nano scale is a challenging problem due to the complex viscoelastic properties and structure. Using molecular-dynamics simulations, we investigate how a graphene sheet on top of a semicrystalline polymer (PVA) affects the friction and wear.

Results: Our setup is meant to resemble an AFM experiment with a silicon tip. We have used two different graphene sheets: an unstrained, flat sheet, and one that has been crumpled before being deposited on the polymer.

Conclusion: The graphene protects the top layer of the polymer from wear and reduces the friction. The unstrained flat graphene is stiffer, and we find that it constrains the polymer chains and reduces the indentation depth.
Yeni Nesil Tehdit: Derin Kurgu (DeepFake)
Authors: ÖZDEMİR Şebnem
Published: September 2021

İnsanlık tarihi boyunca en önemli olgulardan biri bilgiye erişebilmektir. Özellikle sanayi toplumundan bilgi toplumuna geçişle birlikte, bu olgu daha baskın hâle gelmiştir. İnternetin keşfi, yaygınlaşması, akıllı telefonlar sayesinde zaman ve mekândan bağımsız bir şekilde bağlantılı kalabilmek, bilgiye erişimi daha da kolaylaştırmıştır. Ancak bu erişim kolaylığı zamanla büyük bir zorluğa dönüşmüş, insanlığı daha kaliteli bilgiye kolaylıkla sahip olmaktan çok, bilgi ile mücadele eder bir hâle getirmiştir (Kominiarczuk and Ledzińska, 2014) (Özdemir, 2016)....
STUDI MENGENAI PENINGKATAN SIKAP PENGGUNA SHOPEE MELALUI KEPERCAYAAN
Authors: Nur Fitriana Annisa Rizky , Trishananto Yudha
Published: September 2021

Penelitian ini bertujuan untuk mengetahui Sikap Belanja Online di Shopee dipengaruhi oleh Islamic branding, perceived benefit dan electronic word of mouth melalui Kepercayaan. Penelitian dilakukan dengan metode kuantitatif. Populasi yang digunakan yaitu pelanggan aplikasi shopee. Sampel yang digunakan adalah pelanggan yang pernah memakai aplikasi shopee ketika berbelanja online dengan jumlah sampel sebanyak 95 orang. Langkah pengambilan sampel dengan purposive sampling. Penelitian yang dilakukan dengan analisis regresi linier berganda melalui bantuan aplikasi SPSS 25.0. Hasil yang diperoleh Islamic branding, perceived benefit dan electronic word of mouth terdapat pengaruh positif serta tidak signifikan terhadap kepercayaan, Islamic Branding, dan perceived benefit terdapat pengaruh positif terhadap sikap belanja online. electronic word of mouth terdapat pengaruh positif serta tidak signifikan terhadap sikap belanja online. Kepercayaan berpengaruh positif dan tidak signifikan terhadap sikap belanja online. Adanya kepercayaan tidak mampu menjadi mediasi pengaruh Islamic branding, perceived benefit dan electronic word of mouth terhadap sikap belanja online.
PENGARUH INSENTIF TERHADAP KINERJA PENGEMUDI GRAB BIKE DI KOTA KUPANG
Authors: Nati Agnes , Timuneno Tarsisius , Fanggidae Rolland Epafras
Published: September 2021

Penelitian ini bertujuan untuk mengetahui pengaruh insentif terhadap kinerja pengemudi Grab Bike di Kota Kupang. Penelitian ini merupakan penelitian asosiatif dengan menggunakan dengan menggunakan pendekatan kuantitatif. Teknik pengumpulan data dilakukan dengan menyebarkan kuesioner, melakukan observasi serta wawancara. Teknik analisis data yang digunakan dalam penelitian ini adalah regresi linear sederhana. Penelitian ini dilakukan pada para pengemudi Grab Bike di kota Kupang dengan sampel sebanyak 83 pengemudi. Hasil analisis data menunjukan bahwa Insentif berpengaruh positif terhadap kinerja pengemudi Grab Bike di kota Kupang. Temuan tersebut dapat menjadi bahan evaluasi manajemen Grab di Kota Kupang agar dapat menigkatkan program insentif bagi para pengemudi sehingga dapat mendorong pengemudi untuk berkinerja baik.
Antidiabetic green leafy vegetables currently sold in Trincomalee District in Sri Lanka
Authors: SHANMUGALİNGAM Vinujan , VİVEKANANDARAJAH SATHASİVAMPİLLAİ Saravanan , SEBASTİAN Pholtan Rajeev
Published: September 2021

Diabetes is a disease in which the body does not produce insulin or cannot use insulin effectively. In Sri Lanka, 1.2 million people among the age group of 20 to 79 were affected by diabetes in 2019. Biomedicine antidiabetic medications cause common side effects such as bladder cancer, dehydration, sinusitis, kidney illness, and urinary infections. Consumption of green leafy vegetables minimizes the risk of developing diabetes. Hence, this work aims to identify and document the green leafy vegetables currently sold in Trincomalee District in Sri Lanka by performing fieldwork visits to the main markets and the surrounding green leafy vegetable kiosks, shops, superstores, and streets from January 2019 to June 2021. The levels of antidiabetic scientific evidence available for the identified green leafy vegetable species were assessed by recognizing the relevant published works in the electronic databases Web of Science, PubMed, Scopus, etc., until September 2021. A total of 99 green leafy vegetable species from 43 families were recognized. The majority of the green leafy vegetables had in vivo (33%), followed by in vitro (16%) and clinical (9%) as scientific evidences. Also, 49 antidiabetic compounds were already isolated from the identified green leafy vegetables. This study forms a foundation for further studies using the green leafy vegetable species in Trincomalee.
Agile Approach for E-Learning in Digital-Leadership Training for Small and Medium Enterprises
Authors: Hage Roger , Lovasz-Bukvova Helena , Hopp Matej , Hölzl Marvin , Kormann-Hainzl Gerhard , Reiner Michael , Dhungana Deepak
Published: September 2021

Training for small and medium enterprises, especially in the context of leadership and digitalisation, has been traditionally carried out in form of presence workshops. Like other learning and training offers, this type of training needed to be carried out virtually during the COVID-19 pandemic, bringing advantages as well as disadvantages. Furthermore, the purpose of such courses is typically to convey a curriculum of preselected content and skills previously deemed useful. This paper presents the experiences from a mini-course on digital leadership carried out virtually during the pandemic that aims to incorporate SME needs in an agile manner. The presented mini-course is being developed using action research approach and aims to provide input for designing training in this context beyond the current crisis. The findings show high acceptance by the participants for the 100% virtual format and the effectiveness of the pilot run was proven to increase the digital skills of the participants. Engaging participants in order to reflect their needs has proven challenging and will be considered in the next action iteration.
Exploring Engagement in Online Videos for Language Learning through YouTube’s Learning Analytics
Authors: Dolores Maria , Mañana-Rodriguez Jorge
Published: September 2021

Until a few years ago, video analytics were not accessible to learning stakeholders, mainly because online video platforms did not share the users’ interactions on the system with stakeholders. However, this scenario has changed, and currently YouTube, the world’s largest media sharing site, offers these data. YouTube is also the main tool for transmitting audio-visual content in Language MOOCs (massive open online courses), and its video engagement data can be monitored through the YouTube Studio channel, which provides free and open access to video analytics. In this paper we present our research based on the analysis of viewers’ engagement with 35 videos of the Language MOOC entitled Alemán para hispanohablantes: basic principles (German for Spanish-speakers). The data provided by the YouTube Studio Learning Analytics platform has enabled new insights related to participants’ watching of these videos in Language MOOCs (LMOOCs). The results of our study provide pedagogical implications for Foreign Language instructors concerning the use of videos in language learning.
Creating Mature Blended Courses: The European Maturity Model Guidelines
Authors: Goeman Katie , Dijkstra Wiebe
Published: September 2021

The pandemic has urged European universities and other institutions of higher education to switch in a very limited time from on-campus to remote teaching or to teaching modes that combine online and face-to-face activities. Instructors, as well as other course designers and support service staff are in search of evidence-based frameworks that show how to incorporate proven blended scenarios, adapted to their context. Between 2017 and 2020 seven European project partners collaborated in order to establish a conceptual and operational framework for blended education and teaching, labelled as the European Maturity Model for Blended Education. Its aim is to map blended learning practices, conditions, strategies and policies in a systematic manner and to empower higher education institutions to achieve up-scaled blended courses. In this contribution, we focus on what has been developed with regard to the course level. First, we describe the dimensions and indicators of the model, next we indicate blended courses might be altered in terms of their level of maturity using a series of guidelines and open-source tools and materials. We conclude by proposing how to employ the guidelines in a workshop setting.
Reconstructing Subjective Study Experiences during Shutdown in Pandemic Times
Authors: Eigbrecht Laura , Ehlers Ulf-Daniel
Published: September 2021

The article reports on a qualitative study based on interviews with students systematically conducted online since March 2020. A total of 13 individual and eleven group interviews on the personal study situation during the Corona shutdown have been conducted, analysed and evaluated. The students’ perspectives provide insights into how they subjectively reconstruct and classify the experiences they have made, what conclusions can be drawn from this for future higher education and how higher education institutions must evolve in order to support students in the best possible way. In addition to numerous challenges, the pandemic has brought forth the potential of students to shape and reflect on their learning processes in a self-determined and self-organised way and to contribute as experts to shaping the future of higher education.
“Mission Possible”: Supporting an Adoption of a Distance Learning Model for Schools during the Pandemic
Authors: Spilker Maria , Rocha Antonieta , Afonso Ana , Morgado Lina
Published: September 2021

This investigation relates to the professional development of in-service teachers on online teaching in K-12/P-12 schools during the COVID-19 pandemic. The main questions concerned the autonomy and support from/in schools, alternatives found and implemented. A model was developed and applied in different institutions. This article will focus on analysing the results of one Portuguese school.The study follows a Design-Based-Research methodology. The results revealed teachers have knowledge gaps regarding intermediate/advanced digital skills. Through the training course, teachers’ awareness was raised about the distinction between Remote Education and Distance Learning and some skills inherent to online teaching were developed.
Service Learning for Enhancing Student Civic Engagement
Authors: Skledar Matijević Ana , Tomašević Teresa , Lindhagen Lasse
Published: September 2021

The NEXUS project focuses on cultural diversity and migration within higher education institutions (HEIs), and enhancing student civic engagement by integrating Service Learning elements into second language courses, i.e. teaching the language of the receiving country.Service Learning as an educational method and as an integral activity of community engagement is crucial for the NEXUS project because it explicitly promotes cooperation between the academic community and the civil sector, putting the students and community engagement at the core of the learning experience. It also contributes to the achievement of the third mission of the university, which directly facilitates the development of the social responsibility of students and other members of the academic community in solving specific societal problems.A Service Learning idea developed through NEXUS is based on second language courses which contain elements of culture and society of the receiving country and therefore lend themselves to including civic education and civic engagement elements for empowering students in the syllabus.
Developing soft Skills through Active Learning: Storytelling Concrete Experiences through a MOOC
Authors: Tomasini Alessandra , Baudo Valeria , Arnold Deborah
Published: September 2021

The eLene4Life project aims to support curriculum innovation in higher education (HE) through the development of active learning approaches for transversal skills, with the ultimate aim of improving students’ employability. The MOOC “Active Learning for Soft Skills Development”, one of the project outputs, has been put in place as a space for learning through experience sharing and discussion. The MOOC aims at fostering the exchange of results achieved by instructors after the concrete experimentation of active learning methods and at increasing their sensibility and knowledge of the most effective modalities through which to implement those methods. This paper outlines the genesis of the MOOC. Its three main objectives are: (a) collecting and valorising different voices of the teachers who directly experimented one or more methodologies of active learning in their classroom (most of them during the pandemic); (b) embracing and sustaining experiences, as well as addressing doubts coming from a wider audience interested in putting into practice such methods oriented to soft and digital skills’ development; (c) offering a non-formal learning opportunity in line with European indications about micro-credentialing through developing synergies with the ECCOE project (European Credit Clearinghouse for Opening up Education).
How Doba Business School Adopted its Business Model due to Coronavirus Pandemic?
Authors: Letonja Marina , Veingerl Čič Živa , Maček Anita , Divjak Marko
Published: September 2021

The coronavirus pandemic (pandemic) is posing difficult and unpredictable challenges for Higher Education Institutions (HEIs). They have to adapt their business models (BMs), traditional working mechanisms and the way they transfer their knowledge to their students. The aim of this paper is to show how HEI of applied sciences overcame these challenges, and how they adapted its BM. The case study methodology was used. Based on the case of DOBA Business School Maribor, Slovenia, authors present how it reacted to the changed business and education circumstances. Discussion and concluding remarks stress out the lessons Doba Business School has learned from the pandemic so far and how these insights can help other HEIs to change their BMs in order to cope better in these challenging times.
FIM DO IMPÉRIO. MUDANÇAS SOCIAIS E CONTEXTOS HISTÓRICOS E POLÍTICOS. POSICIONAMENTO DO BRASIL EM RELAÇÃO A SI PRÓPRIO E AS RELAÇÕES COM O EXTERIOR
Authors: De Abreu Rodrigues Fabiano
Published: September 2021

O objetivo deste trabalho é compreender de que forma o panorama político alterou toda uma sociedade, de que forma o fim do império mudou os contextos históricos, sociais e econômicos de todo o país. É ainda de ressaltar a mudança na forma como o Brasil se posicionou em relação a si próprio e ao exterior com o fim do império. Documentação e outros textos de investigação sobre o tema foram usados para a elaboração deste trabalho. Para a realização do trabalho foram analisados vários documentos desdediscursos parlamentares, cartas pessoais, artigos e editoriais jornalísticos, além das principais obras que compõem a bibliografia sobre o assunto. As três últimas décadas do Império Brasileiro serão as mais focadas, desde a guerra Paraguai vs Brasil (13/12/1864) e finalização no golpe militar que derrubou o último gabinete do Império, e na seqüência o próprio regime monárquico  15/11/1889). Para uma melhor compreensão do processo que culminou com a mudança de regime no Brasil, procedemos a investigação dos principais eventos que lhe precederam, e também a busca de apreensão do sentido da ação de seus principais agentes históricos, permitindo-nos assim vislumbrar as conjunções entre História e personalidade.
Principles, assessment and methods of risk management of investment activities of the enterprise
Authors: Kraus Kateryna , Kraus Nataliia , Pochenchuk Galyna
Published: September 2021

In the article, authors explored the essence and content of the concept of “investment risk”, as well as identified factors influencing investment risk. The classification of investment risks on various grounds is carried out and scientific approaches to understanding the essence of “investment risk management” are considered. It is reasonable to manage the risks of investment activities of the enterprise in three stages: risk identification, risk measurement and risk control. Two directions of risk management of investment activity of the enterprise are described, namely: the policy directed on direct reduction of risk and the policy directed on minimization of possible negative consequences of risk. The principles of risk management of investment activity of the enterprise are characterized, such as awareness of risk acceptance, manageability, compatibility, accounting, taking into account the possibility of risk transfer. Peculiarities of application of risk management methods of investment activity of the enterprise (transfer, retention and risk avoidance) are revealed. The authors consider several risk management strategies for investment activities of the enterprise: asset allocation, diversification, hedging, investment valuation, investment restrictions. The advantages and disadvantages of methods for assessing the risks of investment activities of the enterprise (expert assessment, SWOT-analysis, method of analogies, adjusting the discount rate) are highlighted. Authors considered qualitative and quantitative scientific approaches to assessing the risks of investment activities of the enterprise. It is proved that one of the industries that is significantly exposed to the risks of investment activity is the telecommunications industry, which is exposed to the following risks: economic and legal, socio-political, technological and financial. The key directions of investment by enterprises of the telecommunication sphere are investigated – Crown Castle International, Amdocs Limited, Xilinx, Inc, Qualcomm, Verizon Communications. The article considers the local and telecommunication levels of investment activity risks, as well as suggests directions for risk management of investment activities of the enterprise.
Assessing the impact of globalization on stock market in Ukraine
Authors: Zadorozhna Tetyana
Published: September 2021

The article is devoted to studying the impact of globalization processes on the development of national economies. In particular, the indicators of assessing the impact of globalization on financial and non-financial indicators of countries' development are considered. Attention is paid to the place of Ukraine in the KOF Globalization Index 2020 ranking, namely in terms of economic, social, and political globalization. The author has formed three groups of indicators that allow assessing the influence of globalization on the securities market of a country. The first group includes indicators that help determine the degree of integration of the national securities market into the global one. The second group includes indicators that determine the extent to which domestic securities legislation and principles of securities market regulation are adapted to international standards. The third group of indicators is aimed at quantifying the impact of trends in the global securities market on the national. The article examines the impact of one of the indicators of the third group on the securities market of Ukraine. In particular, the correlation analysis of the relationship between the Ukrainian PFTS index and the indices of American, British, European, and Polish stock markets was conducted. The author made conclusions about the availability of the significant correlation between global stock indices, as well as the weak impact of global securities market trends on the dynamics of the Ukrainian market. It was also revealed during the analysis, that the level of correlation between indices depends on whether the financial market is in crisis. Particularly, the analysis covered three periods: the 2008-2010 financial crisis, the 2020-2021 Covid-19 crisis, and the 2010-2020 period between the crises.
Structural and regional characteristics of the world retail trade leaders
Authors: Kavun-Moshkovska Olha
Published: September 2021

The state of development of world retail trade through the prism of the TOP 250 retailers functioning is considered in the article. As part of the study the main performance indicators of Top 250 retailers for 2013-2020 have been analyzed. The world's leading retail trade networks have been performing positive dynamics of their development and a slight increase in the values of indicators. This might take place due to the stabilization of the level of globalization of retail trade as the result of active development of e-commerce and m-commerce. Retailers were also affected by such negative macroeconomic factors as slow economic growth in major developed economies, high levels of debt in emerging countries, deflation or low inflation in rich countries, a protectionist backlash against globalization, troubled credit markets in some countries, and worsening demographics in many countries. The size of retail revenue in 2020 helped us define five groups of trade networks. In addition, we determined the share of Top 250 companies by region/country in 2013-2019 and their revenue. The companies from Europe and North America have shown leading positions in the structure of Top-250 retailers in terms of retail revenue share in 2013-2019. The analysis of the features of expansion policy manifestation by trade structures, depending on the region of their origin, have been conducted. The European trade networks, which in 2019 were present on average in 18.3 countries has demonstrated the largest internationalization. The structure of Top 250 companies by product sector is considered as well. FMCG companies were dominated in the structure of the Top 250 retailers. Special attention has also paid to determining the place of European retailers in the Top 250 in the framework of the European model of retail development. This model assumes an active presence of trade networks in the markets of foreign countries.
Food aid in Poland in the years 2014-2019 as an expression of solidarity and European Union support for the national social assistance system
Authors: Fraczek Piotr
Published: September 2021

One of the goals of modern states is to strive for continuous economic development and ensure a high standard of living for their citizens. Social problems of too high intensity, existing in individual countries, may constitute a barrier to achieving this goal. One of the acute social problems in every country in the world is the phenomenon of poverty. The European Union and its member states undertake many measures to reduce poverty. One such activity was the creation of the Fund for European Aid to the Most Deprived (FEAD), which aims to help the poorest by providing food. The program aimed to complement the policy of public authorities in the Member States and to supplement the existing forms of support in the social welfare system. In Poland, the implementation of FEAD has been planned for the years 2014-2020, and this program was a visible manifestation of European solidarity and significant support for the social assistance system. The article aims to identify the level of support that Poland received in 2014-2019 from the European Union under the Fund for European Aid to the Most Deprived (FEAD) and to identify trends and problems in the distribution of food products to the poorest people. The analyzes show that in 2014-2019 Poland received support from EU-FEAD of EUR 416.9 million, which allowed for the provision of almost 299 thousand. tons of food for the poorest. In 2019, as much as 76% of the total food provided to the poor was financed from European funds. In the period 2014-2019, there is a noticeable trend in Poland consisting in increasing the share of food aid from the EU for Poland for the purchase of food for the poorest. This is worrying as the end of the EU-funded FEAD program may result in a significant decrease in the number of poor people receiving support in the form of food aid in Poland. One of the main problems in the distribution of food was the insufficiently developed network of food distribution organizations and the presence of municipalities not covered by the food aid program.
TESS Data for Asteroseismology: Photometry
Authors: Handberg Rasmus , Lund Mikkel N. , White Timothy R. , Hall Oliver J. , Buzasi Derek L. , Pope Benjamin J. S. , Hansen Jonas S. , von Essen Carolina , Carboneau Lindsey , Huber Daniel , Vanderspek Roland K. , Fausnaugh Michael M. , Tenenbaum Peter , Jenkins Jon M. ,   The T’DA Collaboration
Published: September 2021

Over the last two decades, asteroseismology has increasingly proven to be the observational tool of choice for the study of stellar physics, aided by the high quality of data available from space-based missions such as CoRoT, Kepler, K2, and the Transiting Exoplanet Survey Satellite (TESS). TESS in particular will produce more than an order of magnitude more such data than has ever been available before. While the standard TESS mission products include light curves from 120 s observations suitable for both exoplanet and asteroseismic studies, they do not include light curves for the vastly larger number of targets observed by the mission at a longer 1800 s cadence in Full Frame Images (FFIs). To address this lack, the TESS Data for Asteroseismology (T’DA) group under the TESS Asteroseismic Science Consortium (TASC) has constructed an open-source pipeline focused on producing light curves for all stars observed by TESS at all cadences, currently including stars down to a TESS magnitude of 15. The pipeline includes target identification, background estimation and removal, correction of FFI time stamps, and a range of potential photometric extraction methodologies, though aperture photometry is currently the default approach. For the brightest targets, we transparently apply a halo photometry algorithm to construct a calibrated light curve from unsaturated pixels in the image. In this paper, we describe in detail the algorithms, functionality, and products of this pipeline and summarize the noise metrics for the light curves. Companion papers will address the removal of systematic noise sources from our light curves, and a stellar variability classification from these.
L 98-59: A Benchmark System of Small Planets for Future Atmospheric Characterization
Authors: Pidhorodetska Daria , Moran Sarah E. , Schwieterman Edward W. , Barclay Thomas , Fauchez Thomas J. , Lewis Nikole K. , Quintana Elisa V. , Villanueva Geronimo L. , Domagal-Goldman Shawn D. , Schlieder Joshua E. , Gilbert Emily A. , Kane Stephen R. , Kostov Veselin B.
Published: September 2021

The M3V dwarf star L 98-59 hosts three small (R < 1.6 R
⊕) planets. The host star is bright (K = 7.1) and nearby (10.6 pc), making the system a prime target for follow-up characterization with the Hubble Space Telescope (HST) and the upcoming James Webb Space Telescope (JWST). Herein, we use simulated transmission spectroscopy to evaluate the detectability of spectral features with HST and JWST assuming diverse atmospheric scenarios (e.g., atmospheres dominated by H2, H2O, CO2, or O2). We find that H2O and CH4 present in a low mean molecular weight atmosphere could be detected with HST in one transit for the two outermost planets, while H2O in a clear steam atmosphere could be detected in six transits or fewer with HST for all three planets. We predict that observations using JWST/NIRISS would be capable of detecting a clear steam atmosphere in one transit for each planet and H2O absorption in a hazy steam atmosphere in two transits or less. In a clear, desiccated atmosphere, O2 absorption may be detectable for all three planets with NIRISS. If the L 98-59 planets possess a clear, Venus-like atmosphere, NIRSpec could detect CO2 within 26 transits for each planet, but the presence of H2SO4 clouds would significantly suppress CO2 absorption. The L 98-59 system is an excellent laboratory for comparative planetary studies of transiting multiplanet systems, and observations of the system via HST and JWST would present a unique opportunity to test the accuracy of the models presented in this study.
Synthetic Absorption Lines from Simulations of Multiphase Gas in Galactic Winds
Authors: de la Cruz Lita M. , Schneider Evan E. , Ostriker Eve C.
Published: September 2021

Supernova-driven galactic winds are multiphase streams of gas that are often observed flowing at a range of velocities out of star-forming regions in galaxies. In this study, we use high-resolution 3D simulations of multiphase galactic winds modeled with the hydrodynamics code Cholla to investigate the connection between numerical studies and observations. Using a simulated interaction between a hot T ∼ 107 K supernova-driven wind and a cool T ∼ 104 K cloud of interstellar material, we create mock observables, including the optical depth (τ) and covering fraction (C

f
), of six commonly observed ions (Si ii, C ii, Si iv, C iv, N v, and O vi) as a function of gas velocity. We compare our mock observables to surveys of galactic winds in the literature, finding good agreement with velocities and profiles of the low ions. We then compute “empirical” values for the optical depth and covering fraction following observational techniques, and compare them to the values calculated directly from the simulation data. We find that the empirically computed values tend to underestimate the “true” value of τ for ions with high optical depth and overestimate the “true” value of τ for ions with low optical depth relative to the simulated data. The empirically estimated covering fractions match our direct calculations very well for the low-ionization ions; for the high-ionization ions, the empirical covering fractions underestimate the directly computed values by up to ∼40%.
Magnetic Energy Release, Plasma Dynamics, and Particle Acceleration in Relativistic Turbulent Magnetic Reconnection
Authors: Guo Fan , Li Xiaocan , Daughton William , Li Hui , Kilian Patrick , Liu Yi-Hsin , Zhang Qile , Zhang Haocheng
Published: September 2021

In strongly magnetized astrophysical plasma systems, magnetic reconnection is believed to be the primary process during which explosive energy release and particle acceleration occur, leading to significant high-energy emission. Past years have witnessed active development of kinetic modeling of relativistic magnetic reconnection, supporting this magnetically dominated scenario. A much less explored issue in studies of relativistic reconnection is the consequence of three-dimensional dynamics, where turbulent structures are naturally generated as various types of instabilities develop. This paper presents a series of three-dimensional, fully kinetic simulations of relativistic turbulent magnetic reconnection (RTMR) in positron–electron plasmas with system domains much larger than kinetic scales. Our simulations start from a force-free current sheet with several different modes of long-wavelength magnetic field perturbations, which drive additional turbulence in the reconnection region. Because of this, the current layer breaks up and the reconnection region quickly evolves into a turbulent layer filled with coherent structures such as flux ropes and current sheets. We find that plasma dynamics in RTMR is vastly different from its 2D counterpart in many aspects. The flux ropes evolve rapidly after their generation, and can be completely disrupted by the secondary kink instability. This turbulent evolution leads to superdiffusive behavior of magnetic field lines as seen in MHD studies of turbulent reconnection. Meanwhile, nonthermal particle acceleration and the timescale for energy release can be very fast and do not depend strongly on the turbulence amplitude. The main acceleration mechanism is a Fermi-like acceleration process supported by the motional electric field, whereas the nonideal electric field acceleration plays a subdominant role. We also discuss possible observational implications of three-dimensional RTMR in high-energy astrophysics.
The Study of X-Ray Flux Variability of M87
Authors: Imazawa Ryo , Fukazawa Yasushi , Takahashi Hiromitsu
Published: September 2021

We searched for a short-term X-ray variability of the M87 core and jet from archival X-ray data with long exposure data taken by the Suzaku, Chandra, and NuSTAR telescopes. We found the intraday variability for the Suzaku data obtained in 2006, and for the Chandra core obtained in 2017. The intraday variability suggested a minute emission region about the size of the Schwarzschild radius of the M87 supermassive black hole. Suzaku could not resolve a core and HST-1; however, in 2006, HST-1 was much brighter than the core, and thus, the variability is likely due to the HST-1. Since the photon index in 2006 was 2.38, the emission was possibly synchrotron emission from the local shock region in the HST-1, indicating that the particle acceleration of TeV electrons occurred far away (∼100 pc) from the core. Assuming the fading time to be equal to the synchrotron cooling time, the magnetic field is constrained to be B ∼ 1.94 δ
1/3 mG. Moreover, the photon index of the core in 2017 was approximately 1.96; thus, the possible emission was from the radiative inefficiency accretion flow of the core or inverse Compton scattering in the jet. Intraday time variability prefers the latter possibility.
The Nature of Jets in Double-peaked Emission-line AGN in the KISSR Sample
Authors: Kharb P. , Subramanian S. , Das M. , Vaddi S. , Paragi Z.
Published: September 2021

Double-peaked emission-line AGN (DPAGN) have been regarded as binary black hole candidates. We present here results from parsec-scale radio observations with the Very Long Baseline Array (VLBA) of five DPAGN belonging to the KISSR sample of emission-line galaxies. This work concludes our pilot study of nine type 2 Seyfert and LINER DPAGN from the KISSR sample. In the nine sources, dual compact cores are only detected in the “offset AGN,” KISSR 102. However, the overall incidence of jets in the eight sources that were detected with the VLBA is ≥60%. We find a difference in the “missing flux density” going from the Very Large Array to VLBA scales between Seyferts and LINERs, with LINERs showing less missing flux density on parsec-scales. Using the emission-line modeling code, MAPPINGS III, we find that the emission lines are likely to be influenced by jets in 5/9 sources. Jet-medium interaction is the likely cause of the emission-line splitting observed in the SDSS spectra of these sources. Jets in radio-quiet AGN are therefore energetically capable of influencing their parsec- and kpc-scale environments, which makes them agents of “radio AGN feedback” (similar to radio-loud AGN).
Thresholds for Particle Clumping by the Streaming Instability
Authors: Li 李 Rixin 日新 , Youdin Andrew N.
Published: September 2021

The streaming instability (SI) is a mechanism to aerodynamically concentrate solids in protoplanetary disks and trigger the formation of planetesimals. The SI produces strong particle clumping if the ratio of solid to gas surface density—an effective metallicity—exceeds a critical value. This critical value depends on particle sizes and disk conditions such as radial drift-inducing pressure gradients and levels of turbulence. To quantify these thresholds, we perform a suite of vertically stratified SI simulations over a range of dust sizes and metallicities. We find a critical metallicity as low as 0.4% for the optimum particle sizes and standard radial pressure gradients (normalized value of Π = 0.05). This subsolar metallicity is lower than previous results, due to improved numerical methods and computational effort. We discover a sharp increase in the critical metallicity for small solids, when the dimensionless stopping time (Stokes number) is ≤0.01. We provide simple fits to the size-dependent SI clumping threshold, including generalizations to different disk models and levels of turbulence. We also find that linear, unstratified SI growth rates are a surprisingly poor predictor of particle clumping in nonlinear, stratified simulations, especially when the finite resolution of simulations is considered. Our results widen the parameter space for the SI to trigger planetesimal formation.
Clustered Star Formation in the Center of NGC 253 Contributes to Driving the Ionized Nuclear Wind
Authors: Mills E. A. C. , Gorski M. , Emig K. L. , Bolatto A. D. , Levy R. C. , Leroy A. K. , Ginsburg A. , Henshaw J. D. , Zschaechner L. K. , Veilleux S. , Tanaka K. , Meier D. S. , Walter F. , Krieger N. , Ott J.
Published: September 2021

We present new 3 mm observations of the ionized gas toward the nuclear starburst in the nearby (D ∼ 3.5 Mpc) galaxy NGC 253. With ALMA, we detect emission from the H40α and He40α lines in the central 200 pc of this galaxy on spatial scales of ∼4 pc. The recombination line emission primarily originates from a population of approximately a dozen embedded super star clusters in the early stages of formation. We find that emission from these clusters is characterized by electron temperatures ranging from 7000 to 10,000 K and measures an average singly ionized helium abundance 〈Y
+〉 = 0.25 ± 0.06, both of which are consistent with values measured for H ii regions in the center of the Milky Way. We also report the discovery of unusually broad line width recombination line emission originating from seven of the embedded clusters. We suggest that these clusters contribute to the launching of the large-scale hot wind observed to emanate from the central starburst. Finally, we use the measured recombination line fluxes to improve the characterization of overall embedded cluster properties, including the distribution of cluster masses and the fractional contribution of the clustered star formation to the total starburst, which we estimate is at least 50%.
Radiative Transfer Modeling of an SN 1987A Light Echo—AT 2019xis
Authors: Ding Jiachen , Wang Lifan , Brown Peter , Yang Ping
Published: September 2021

We use a Monte Carlo radiative transfer model (MCRTM) to simulate the UBVRI light curves, images, and linear polarization of a light echo from supernova SN 1987A in the Large Magellanic Cloud (LMC) using various dust cloud shapes, sizes, and optical properties. We compare the theoretical simulations to the observations of AT 2019xis, a light echo detected at a large angular distance (4.′05) from SN 1987A. We estimate the size and optical thickness of the dust cloud based on the simulation results and the observations of the Optical Gravitational Lensing Experiment (OGLE-IV) Transient Detection System (OTDS) I-band light curve. The mass of the dust cloud is calculated using the estimated size, optical thickness, and extinction coefficient. If the dust cloud is assumed to correspond to a gas-to-dust ratio of 300, the total mass of the dust cloud is approximately 7.8–9.3 M
⊙. Based on these theoretical models, we show that the morphological shapes of the light echoes in the wavelength range of or shorter than the U band to be very different from those in the longer wavelength bands, and the difference carries important information on the early UV radiation of SN 1987A.
Free Energy Sources in Current Sheets Formed in Collisionless Plasma Turbulence
Authors: Jain Neeraj , Büchner Jörg , Comişel Horia , Motschmann Uwe
Published: September 2021

Collisionless dissipation of macroscopic energy into heat is an unsolved problem of space and astrophysical plasmas, e.g., solar wind and Earth’s magnetosheath. The most viable process under consideration is the turbulent cascade of macroscopic energy to kinetic scales where collisionless plasma processes dissipate the energy. Space observations and numerical simulations show the formation of kinetic scale current sheets in turbulent plasmas. Instabilities in these current sheets (CS) can provide collisionless dissipation and influence the turbulence. Spatial gradients of physical quantities and non-Maxwellian velocity distribution functions provide the free energy sources for CS plasma instabilities. To determine the free energy sources provided by the spatial gradients of plasma density and electron/ion bulk velocities in CS formed in collisionless turbulent plasmas with an external magnetic field
B

0, we carried out two-dimensional particle-in-cell-hybrid simulations and interpret the results within the limitations of the simulation model. We found that ion-scale CS in a collisionless turbulent plasma are formed primarily by electron shear flows, i.e., electron bulk velocity inside CS is much larger than ion bulk velocity while the density variations through the CS are relatively small (<10%). The electron bulk velocity and, thus, the current density inside the sheets are directed mainly parallel to
B

0. The shear in the perpendicular electron and ion bulk velocities generates parallel electron and ion flow vorticities. Inside CS, parallel electron flow vorticity exceeds the parallel ion flow vorticity, changes sign around the CS centers, and peaks near the CS edges. An ion temperature anisotropy develops near CS during the CS formation. It has a positive correlation with the parallel ion and electron flow vorticities. Theoretical estimates support the simulation results.