bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risks and Benefits of Kidney Transplantation during the COVID-19 Pandemic: Transplant or Not Transplant?
Authors: Ajaimy Maria , Liriano-Ward Luz , Graham Jay A. , Akalin Enver 
Published: May 2021

Abstract
COVID-19 has significantly affected the transplant community, by leading to decreased transplant activity and increased waiting list time. As expected, COVID-19 causes substantial mortality in both ESKD and kidney transplant populations. This is due to underlying CKD and a high prevalence of comorbid conditions, such as diabetes mellitus, hypertension, and cardiovascular disease in this group. Transplant programs have faced the difficult decision of weighing the risks and benefits of transplantation during the pandemic. On one hand, there is a risk of COVID-19 exposure leading to infection while patients are on maximum immunosuppression. Alternatively, there are risks of delaying transplantation, which will increase waitlist times and may lead to waitlist-associated morbidity and mortality. Cautious and thoughtful selection of both the recipient’s and donor’s post-transplant management has been required during the pandemic, to mitigate the risk of morbidity and mortality associated with COVID-19. In this review article, we aimed to discuss previous publications related to clinical outcomes of COVID-19 disease in kidney transplant recipients, patients with ESKD on dialysis, or on the transplant waiting list, and the precautions transplant centers should take in decision making for recipient and donor selection and immunosuppressive management during the pandemic. Nevertheless, transplantation in this milieu does seem to be the correct decision, with careful patient and donor selection and safeguard protocols for infection prevention. Each center should conduct risk assessment on the basis of the patient’s age and medical comorbidities, waitlist time, degree of sensitization, cold ischemia time, status of vaccination, and severity of pandemic in their region.
Planning aspects in training ice hockey players
Authors: Trandafir Marius , Balint Lorand 
Published: May 2021

Sports training is a long-lasting complex process, organized according to the level of performance and the proposed competitive objective. The study aims at highlighting the planning aspects of the sports training in the preparation of ice hockey players. Training planning is organized according to the team's performance level and the targeted result, thus, it can be classified as follows: stage one, anatomical adaptation, stage two, pre-competition stage, competition stage and the transitional stage. The content of each stage is structured and distributed based on the type of effort specific to the hockey game and the main parameters of effort (volume, intensity, complexity). The research methods used for the elaboration of the study are: the study of specialized literature and the pedagogical observation. Sports training is a pedagogical process, which implies compliance with basic principles that ensure the achievement of the established sporting performance, when the methods and means of training are well chosen, adapted and individualised according to the player's bio-mental-physical abilities and his background on the position in the team.In conclusion, in the course of the sports training process, the physical, physiological, mental and intellectual potential of the sportsman will be improved, through planning and periodization elements, which ensure the achievement of high-level sports performance.
REFLEXÕES SOBRE A REGULARIZAÇÃO FUNDIÁRIA DO ASSENTAMENTO DO GLÓRIA NA CIDADE DE UBERLÂNDIA – MG
Authors: Ramires Júlio Cesar 
Published: May 2021

Este artigo reflete sobre o processo de regularização fundiária do Assentamento do Glória em Uberlândia, tendo como recursos metodológicos a pesquisa documental, os trabalhos de campo e a realização de entrevistas informais com atores-chaves. As políticas de regularização fundiária urbana precisam ser associadas a outras políticas públicas para interromper o ciclo infinito de reprodução de novas ocupações irregulares. Os três anos de implantação do projeto de regularização não foram suficientes para implantar todas as ações, sendo um período pequeno para se realizar um balanço das ações. Percebeu-se elevada inadimplência no pagamento das parcelas por parte dos moradores que poderão comprometer a realização de diversas obras na área, tais como a construção dos sistemas de abastecimento de água e esgotamento sanitário, sistema de drenagem pluvial e de pavimentação, já que é a única fonte de recursos prevista para implementar essas ações. Constatou-se também a comercialização de moradias por parte dos moradores que pode estar associado às dificuldades de honrar com os compromissos de pagamento das mensalidades ou por causa do processo de valorização da área dando margem a processos especulativos. O processo de regularização do Assentamento do Glória repete os mesmos problemas constatados em pesquisas acadêmicas sobre o tema em outras localidades.
Single-beam three-axis optically pumped magnetometers with sub-100 femtotesla sensitivity
Authors: Xiao Wei , Wu Yulong , Zhang Xiangzhi , Feng Yulong , Sun Chenxi , Wu Teng , Chen Jingbiao , Peng Xiang , Guo Hong 
Published: May 2021

Abstract
We demonstrate a single-beam three-axis parametric-resonance magnetometer operated in near-zero fields. By reflecting the incident laser beam at 90° in the vapor cell and applying three orthogonal parametric modulation fields, the three components of the magnetic field can be extracted from the transmitted light signal. Our vector magnetometer experimentally demonstrates magnetic-field sensitivities of 30 fT Hz−1/2 along x- and y-axes and 70 fT Hz−1/2 along the z-axis, and features a compact single-beam architecture, which is particularly attractive for applications requiring highly sensitive measurements of the vector components of magnetic fields with low power consumption and miniaturized magnetometers, such as magnetoencephalography and magnetocardiography.
Rotulagem do café e certificações de sustentabilidade Significado e importância para a sociedade
Authors: Silva Joana F. , Oliveira M. Beatriz P. P. , Alves Rita C. 
Published: May 2021

O planeta está a sofrer alterações cada vez mais rápidas, com consequências devastadoras para a agricultura e as comunidades que a utilizam como principal meio de subsistência. O café é um dos produtos agrícolas mais transacionados e a matéria-prima de uma das bebidas mais consumidas e apreciadas. Porém, o seu cultivo feito em países maioritariamente subdesenvolvidos, e os cafeicultores dependem quase exclusivamente de seu cultivo. Pelo referido, surgiram as Voluntary Sustainability Standards (VSS), certificações que visam garantir melhor qualidade de vida dos trabalhadores e, simultaneamente, que o café seja produzido de forma mais sustentável. Nesta revisão, são abordadas questões sobre as diversas certificações do café e os domínios da sustentabilidade em que atuam (ambiental, econômico e social). Um dos principais objetivos é dar a conhecer estes tópicos, uma vez que ainda são bastante desconhecidos/desvalorizados pelos consumidores. Como complemento, apresentam-se outras informações que constam dos rótulos das embalagens de café vendido em Portugal, que certamente serão mais úteis se forem do conhecimento do consumidor. Adquirir café certificado é certamente uma forma de colaborar com os objetivos deste tipo de certificações e um meio de conhecer um pouco da história do produto consumido.
CHOOSING A METHOD FOR ESTIMATING THE PARAMETERS OF LINEAR REGRESSION BASED ON IDENTIFICATION OF ANOMALOUS OBSERVATIONS
Authors: Носков С.И. 
Published: May 2021

Описываются свойства методов оценивания параметров регрессионных моделей - наименьших квадратов, модулей, антиробастного, а также их применения для решения конкретных практических проблем. При этом метод наименьших модулей не реагирует на аномальные наблюдения выборки, метод антиробастного оценивания сильно отклоняет линию регрессии в их направлении, метод наименьших квадратов занимает промежуточное положение. Показано, что если целью построения модели является проведение на ее основе многовариантных прогнозных расчетов значений зависимой переменной, то выбор метода численной идентификации параметров модели следует производить на основе анализа характера выбросов. Если есть основания полагать, что подобные им ситуации могут иметь место в будущем, следует выбрать метод антиробастного оценивания, в противном же случае - метод наименьших модулей. Построена регрессионная модель грузооборота Красноярской железной дороги на основе применения всех трех методов оценивания параметров. Проведен анализ причин, имеющих место в 2010 году в ситуации резкого падения величины грузооборота, которая вполне может характеризоваться как аномальное наблюдение в данных. Сделаны рекомендации по выбору метода оценивания параметров в этом случае
The article describes the properties of methods for estimating the parameters of regression models - least squares, moduli, anti-robust - as well as their application for solving specific practical problems. At the same time, the method of least modules does not respond to anomalous observations of the sample, the method of anti-robust estimation strongly deviates the regression line in their direction, the method of least squares occupies an intermediate position. I show that if the purpose of constructing a model is to carry out multivariate predictive calculations of the values of the dependent variable on its basis, then the choice of a method for the numerical identification of model parameters should be based on an analysis of the nature of emissions. If there is a reason to believe that similar situations may occur in the future, the anti-robust estimation method should be chosen, otherwise - the least modulus method. I built a regression model of the freight turnover of the Krasnoyarsk railway on the basis of the application of all three methods of parameter estimation. I carried out the analysis of the reasons for the situation of a sharp drop in the value of cargo turnover in 2010, which may well be characterized as anomalous observation in the data. I give recommendations on the choice of the parameter estimation method in this case
RESEARCH OF SIGNAL DETECTION ALGORITHMS IN COGNITIVE RADIO NETWORKS
Authors: Гринин Е.Е. , Антиликаторов А.Б. , Четкин О.В. , Новикова И.А. 
Published: May 2021

Основной темой являются некоторые из алгоритмов сканирования радиоспектра и обнаружения сигналов в системе когнитивного радио, а также само когнитивное радио. Данная тема является актуальной, так как применение широкополосных каналов является одним из вариантов организации связи, но при этом возникают некоторое трудности. Например, из-за большого числа пользователей необходимо более рационально использовать спектр радиочастот. Рассматриваются основные аспекты обнаружения сигнала в узкополосных и широкополосных диапазонах. Рассказывается о недостатках адаптивных алгоритмов обнаружения, основанных на стандартных законах распределения. Приведены примеры как параметрических, так и непараметрических алгоритмов обнаружения. Подробно описывается алгоритм, основанный на критерии Уилкоксона. При помощи критерия Неймана-Пирсона можно сравнивать обнаружители между собой. Сделаны выводы о целесообразности применения для мониторинга радиоспектра непараметрических алгоритмов обнаружения. Для случая постоянного положительного сигнала на фоне гауссовской помехи сравнение значений асимптотической относительной эффективности для критерия Уилкоксона со значением линейного обнаружителя составляет порядка 0,955. Это значение говорит о том, что оба обнаружителя практически не уступают друг другу в таких условиях
The article discusses some of the algorithms for scanning the radio spectrum and detecting signals in the cognitive radio system, as well as the cognitive radio itself. This topic is relevant since the use of broadband channels is one of the options for organizing communication. Due to a large number of users, it is necessary to more rationally use the radio frequency spectrum. We considered the main aspects of the detection of the signal in narrowband and broadband bands. We described the lack of adaptive detection algorithms based on the standard distribution laws. We give examples of both parametric and non-parametric detection algorithms. We described the algorithm based on Wilcoxon's criteria in detail. Using the Neuman-Pearson's criterion, you can compare the detectors among themselves. We made conclusions about the feasibility of application for monitoring the radiospectract of non-parametric detection algorithms. For the case of a constant positive signal against the background of Gaussian interference, comparing the values of asymptotic relative efficiency for the Wilcoxon’s criterion with the value of the linear detector is about 0.955. This value suggests that both detectors are practically inferior to each other in such conditions
PENGGUNAAN STRATEGI PENEMUAN TERBIMBING (MODEL DISCOVERY) UNTUK MENINGKATKAN HASIL BELAJAR BAHASA BALI
Authors: Kinten I Gede 
Published: May 2021

ABSTRAK
Penelitian ini bertujuan untuk meningkatkan hasil belajar Bahasa Balisiswa kelas VII A semester I tahun pelajaran 2019/2020SMP Negeri 1 Denpasardengan jumlah subjek 44orang.Hasil belajar Bahasa Balisecara umum masih belum mencapai ketuntasan belajar yang ditetapkan sekolah ini.Jenis penelitian ini adalah penelitian tindakan kelas yang terdiri dari perencanaan, pelaksanana tindakan, observasi, evaluasi dan refleksi. Penelitian ini dilaksanakan dalam dua siklus dengan tiga kali tatap muka untuk setiap siklus. Data hasil belajar Bahasa Balisiswa dikumpulkan dengan mengunakan tes hasil belajar Bahasa Balisesudah diberikan pembelajaran.Hasil penelitian menunjukkan adanya peningkatan pada hasil belajar Bahasa Bali setelah penggunaan Strategi Penemuan Terbimbing (Model Discovery). Pada kegiatan awal nilai rata-rata baru mencapai 70,32 dengan ketuntasan belajar 31,82%. Pada siklus I nilai rata-rata mencapai 78,80dengan ketuntasan belajar sebesar 79,55%. Pada siklus II nilai rata-rata mencapai 83,30dengan ketuntasan belajar sebesar 97,73%. Jadi dari siklus ke siklus pembelajaran mengalami peningkatan sesuai dengan target pencapaian kurikulum yaitu ketuntasan belajar secara klasikal 85,00% dengan nilai minimal sebesar 78,00. Dari penelitian ini dapat disimpulkan bahwa pengggunaan Str
The RR Lyrae Delay-time Distribution: A Novel Perspective on Models of Old Stellar Populations
Authors: Sarbadhicary Sumit K. , Heiger Mairead , Badenes Carles , Mateu Cecilia , Newman Jeffrey A. , Ciardullo Robin , Hallakoun Na’ama , Maoz Dan , Chomiuk Laura 
Published: May 2021

Abstract
The delay-time distribution (DTD) is the occurrence rate of a class of objects as a function of time after a hypothetical burst of star formation. DTDs are mainly used as a statistical test of stellar evolution scenarios for supernova progenitors, but they can be applied to many other classes of astronomical objects. We calculate the first DTD for RR Lyrae variables using 29,810 RR Lyrae from the OGLE-IV survey and a map of the stellar age distribution (SAD) in the Large Magellanic Cloud (LMC). We find that ∼46% of the OGLE-IV RR Lyrae are associated with delay times greater than 8 Gyr (main-sequence progenitor masses less than 1 M
⊙), and consistent with existing constraints on their ages, but surprisingly about 51% of RR Lyrae appear to have delay times of 1.2–8 Gyr (main-sequence masses between 1 and 2 M
⊙ at LMC metallicity). This intermediate-age signal also persists outside the Bar region, where crowding is less of a concern, and we verified that without this signal the spatial distribution of the OGLE-IV RR Lyrae is inconsistent with the SAD map of the LMC. Since an intermediate-age RR Lyrae channel is in tension with the lack of RR Lyrae in intermediate-age clusters (noting issues with small-number statistics), and noting the age–metallicity constraints on LMC stars, our DTD result possibly indicates that systematic uncertainties may still exist in SAD measurements of old stellar populations, perhaps stemming from the construction methodology or the stellar evolution models used. We describe tests to further investigate this issue.
The Photometric Metallicity and Carbon Distributions of the Milky Way’s Halo and Solar Neighborhood from S-PLUS Observations of SDSS Stripe 82
Authors: Whitten Devin D. , Placco Vinicius M. , Beers Timothy C. , An Deokkeun , Lee Young Sun , Almeida-Fernandes Felipe , Herpich Fábio R. , Daflon Simone , Barbosa Carlos E. , Perottoni Hélio D. , Rossi Silvia , Tissera Patricia B. , Yoon Jinmi , Youakim Kris , Schoenell William , Ribeiro Tiago , Kanaan Antonio 
Published: May 2021

Abstract
We report photometric estimates of effective temperature, T
eff, metallicity, [Fe/H], carbonicity, [C/Fe], and absolute carbon abundances, A(C), for over 700,000 stars from the Southern Photometric Local Universe Survey (S-PLUS) Data Release 2, covering a substantial fraction of the equatorial Sloan Digital Sky Survey Stripe 82. We present an analysis for two stellar populations: (1) halo main-sequence turnoff stars and (2) K-dwarf stars of mass 0.58 < M/M
⊙ < 0.75 in the Solar Neighborhood. Application of the Stellar Photometric Index Network Explorer (SPHINX) to the mixed-bandwidth (narrow- plus wide-band) filter photometry from S-PLUS produces robust estimates of the metallicities and carbon abundances in stellar atmospheres over a wide range of temperatures, 4250 < T
eff(K) < 7000. The use of multiple narrow-band S-PLUS filters enables SPHINX to achieve substantially lower levels of “catastrophic failures” (i.e., large offsets in metallicity estimates relative to spectroscopic determinations) than previous efforts using a single metallicity-sensitive narrow-band filter. We constrain the exponential slope of the Milky Way’s K-dwarf halo metallicity distribution function (MDF), λ
10,[Fe/H] = 0.85 ± 0.21, over the metallicity range −2.5 < [Fe/H] < −1.0; the MDF of our local-volume K-dwarf sample is well-represented by a gamma distribution with parameters α = 2.8 and β = 4.2. S-PLUS photometry obtains absolute carbon abundances with a precision of ∼0.35 dex for stars with T
eff < 6500 K. We identify 364 candidate carbon-enhanced metal-poor stars, obtain assignments of these stars into the Yoon–Beers morphological groups in the A(C)-[Fe/H] space, and we derive the CEMP frequencies.
Measuring Stellar Masses of Emission-line Galaxies at 1.2 < z < 1.9
Authors: Nagaraj Gautam , Ciardullo Robin , Lawson Alex , Bowman William P. , Zeimann Greg , Yang Guang , Gronwall Caryl 
Published: May 2021

Abstract
The accurate measurement of stellar masses over a wide range of galaxy properties is essential for better constraining models of galaxy evolution. Emission-line galaxies (ELGs) tend to have better redshift estimates than continuum-selected objects, and have been shown to span a large range of physical properties, including stellar mass. Using data from the 3D-HST Treasury program, in this work, we construct a carefully vetted sample of 4350 ELGs at redshifts of 1.16 < z < 1.90. We combine the 3D-HST emission-line fluxes with far-UV through near-IR photometry, and use the MCSED spectral energy distribution fitting code to constrain the galaxies’ physical parameters, such as their star-formation rate and stellar masses. Our sample is consistent with the z ∼ 2 mass–metallicity relation. More importantly, we show that there is a simple, but tight correlation between stellar mass and absolute magnitude in a near-IR filter, which should prove particularly useful in terms of the rapid calculation of accurate stellar masses for millions of galaxies in upcoming missions such as Euclid, and the Nancy Grace Roman Space Telescope.
Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves. I. Period–Fourier–Metallicity Relations for Fundamental-mode RR Lyrae
Authors: Mullen Joseph P. , Marengo Massimo , Martínez-Vázquez Clara E. , Neeley Jillian R. , Bono Giuseppe , Dall’Ora Massimo , Chaboyer Brian , Thévenin Frédéric , Braga Vittorio F. , Crestani Juliana , Fabrizio Michele , Fiorentino Giuliana , Gilligan Christina K. , Monelli Matteo , Stetson Peter B. 
Published: May 2021

Abstract
We present newly calibrated period–ϕ
31–[Fe/H] relations for fundamental-mode RR Lyrae stars in the optical and, for the first time, mid-infrared. This work’s calibration data set provides the largest and most comprehensive span of parameter space to date, with homogeneous metallicities from −3 ≲ [Fe/H] ≲ 0.4 and accurate Fourier parameters derived from 1980 ASAS-SN (V band) and 1083 WISE (NEOWISE extension, W1 and W2 bands) RR Lyrae stars with well-sampled light curves. We compare our optical period–ϕ
31–[Fe/H] relation with those available in the literature and demonstrate that our relation minimizes systematic trends in the lower and higher metallicity range. Moreover, a direct comparison shows that our optical photometric metallicities are consistent with both those from high-resolution spectroscopy and globular clusters, supporting the good performance of our relation. We found an intrinsic scatter in the photometric metallicities (0.41 dex in the V band and 0.50 dex in the infrared) by utilizing large calibration data sets covering a broad metallicity range. This scatter becomes smaller when optical and infrared bands are used together (0.37 dex). Overall, the relations derived in this work have many potential applications, including large-area photometric surveys with James Webb Space Telescope in the infrared and LSST in the optical.
Undetected Binary Stars Cause an Observed Mass-dependent Age Gradient in Upper Scorpius
Authors: Sullivan Kendall , Kraus Adam L. 
Published: May 2021

Abstract
Young stellar associations represent a key site for the study of star formation, but to accurately compare observations to models of stellar evolution, the age of an association must be determined. The Upper Scorpius region is the youngest section of the Scorpius–Centaurus OB association, which is the largest collection of nearby, young, low-mass stars. The true age of Upper Scorpius is not clear, and an observed mass-dependent age gradient in Upper Scorpius, as well as in other star-forming regions, complicates age measurements. The age gradient may indicate a genuine astrophysical feature or may be an artifact of unrecognized systematic effects in stellar age measurements. We have conducted a synthetic red-optical low-resolution spectroscopic survey of a simulated analog to the Upper Scorpius star-forming region to investigate the effects of unresolved binary stars (which have mass-dependent demographics) on age measurements of a stellar population. We found that the observed mass-dependent age gradient in Upper Scorpius can be explained by a population of undetected binary stars. For a simulated population with an age of 10 (rms = 2) Myr, we measured an age of 10.5 (rms = 3.5) Myr for F stars and of 7.5 (rms = 5.8) Myr for M stars. This discrepancy is caused by the mass-dependent mass ratio distribution and the variable steepness of the mass–luminosity relation. Our results support the previously suggested 10 Myr age for Upper Scorpius, with a small intrinsic age spread.