Miracle-dz/UniFAR-FTUs huggingface dataset:
Bandits with Delayed Anonymous Feedback

We study the bandits with delayed anonymous feedback problem, a variant of the stochastic $K$-armed bandit problem, in which the reward from each play of an arm is no longer obtained instantaneously but received after some stochastic delay. Furthermore, the learner is not told which arm an observation corresponds to, nor do they observe the delay associated with a play. Instead, at each time step, the learner selects an arm to play and receives a reward which could be from any combination of past plays. This is a very natural problem; however, due to the delay and anonymity of the observations, it is considerably harder than the standard bandit problem. Despite this, we demonstrate it is still possible to achieve logarithmic regret, but with additional lower order terms. In particular, we provide an algorithm with regret $O(\log(T) + \sqrt{g(\tau) \log(T)} + g(\tau))$ where $g(\tau)$ is some function of the delay distribution. This is of the same order as that achieved in Joulani et al. (2013) for the simpler problem where the observations are not anonymous. We support our theoretical observation equating the two orders of regret with experiments.
Environmental Impacts: How Comparative Prior Knowledge Affects Students’ Calculus Experience

Abstract This study examined the impact of restricting Calculus 1 and Business Calculus classes based upon whether students had prior calculus experience. We compared the performance and experience of students in sections comprised entirely of those who had previously taken calculus, those who had not previously taken calculus, and those in traditional mixed population sections. No dramatic differences in performance emerged between the mixed and restricted populations; students with prior calculus experience outperformed students without previous experience by similar margins in both settings. However, working with the restricted populations indicated that the two groups have very different needs, which are not always evident in mixed settings. This study did not offer differentiated instruction or assignments to the two populations. Although our study showed no statistical differences between the settings, our experience suggests both student populations could be better served by a course targeting students with backgrounds similar to their own.
Influence of dielectric materials on uniformity of large-area capacitively coupled plasmas for N2/Ar discharges

The effect of the dielectric ring on the plasma radial uniformity is numerically investigated in the practical 450-mm capacitively coupled plasma reactor by a two-dimensional self-consistent fluid model. The simulations were performed for N2/Ar discharges at the pressure of 300 Pa, and the frequency of 13.56 MHz. In the practical plasma treatment process, the wafer is always surrounded by a dielectric ring, which is less studied. In this paper, the plasma characteristics are systematically investigated by changing the properties of the dielectric ring, i.e., the relative permittivity, the thickness and the length. The results indicate that the plasma parameters strongly depend on the properties of the dielectric ring. As the ratio of the thickness to the relative permittivity of the dielectric ring increases, the electric field at the wafer edge becomes weaker due to the stronger surface charging effect. This gives rise to the lower ion density, flux and N atom density at the wafer edge. Thus the homogeneous plasma density is obtained by selecting optimal dielectric ring relative permittivity and thickness. In addition, we also find that the length of the dielectric ring should be as short as possible to avoid the discontinuity of the dielectric materials, and thus obtain the large area uniform plasma.
Global existence of classical solutions, spreading speeds, and traveling waves of chemotaxis models with logistic source on R^N

This dissertation is devoted to the study of the classical Keller-Segel chemotaxis systems with space-time heterogeneous logistic source function on R . Chemotaxis systems are mathematical models describing aggregation phenomena of cells due to chemotaxis. That is, phenomena of directed movement of cells in response to the gradient of a chemical attractant, which may be produced by the cells themselves. We first study the fundamental problems such as local existence and global existence of nonnegative classical solutions for given nonnegative initial function in various spaces. Among our results, we prove that it is enough for the self-limitation coefficient of the logistic source function to be greater than or equal to the chemotaxis sensitivity coefficient to guarantee the existence of time-global classical solutions. Next, we discuss the pointwise and uniform persistence of classical solutions, the existence of positive entire solutions, the existence of time-periodic solution if the logistic function is time-periodic, and, the existence of steady state solutions if the logistic function is time homogeneous. In particular, we show that any classical solution with a positive initial function enjoys pointwise persistence under the same assumption of the existence of time-global classical solution. Moreover, we study the stability of positive entire solutions, and the spreading feature of solutions with compactly supported or front like initials. In this direction, our results recover as a special case the stability and spreading speeds for the classical Fisher-KPP equations. Finally, we establish the existence and non-existence of traveling wave solutions. When the logistic function is homogeneous and the chemotaxis sensitivity coefficient is sufficiently small, we show that there are traveling wave solutions with arbitrarily large speeds and there is no traveling wave solution of arbitrarily small speeds. That is there are positive constant 0 < c− ≤ c+ < ∞ such that for any c ≥ c+, there is a traveling wave solution with speed c connecting the two trivial constant solutions and no such solutions exist with speed c < c−.
Influences of non-uniformities and anisotropies on the flux avalanche behaviors of type-II superconducting films

In this paper, the anisotropic flux avalanche processes in thin square-shaped type-II superconducting films are numerically investigated by solving the coupled nonlinear Maxwell’s equations and the thermal diffusion equations. Influences of the non-uniformities and intrinsic critical current density anisotropies originate from the manufacturing process are considered in the simulation. In addition, we also studied the effect of the extrinsic anisotropy induced by the in-plane magnetic field. The results demonstrate that the non-uniformities and anisotropies of the critical current density play significant roles in the flux avalanche process of the thin film superconductors. Slight anisotropy (either intrinsic or extrinsic) can dramatically change the propagation direction of avalanches in the superconducting film, which is consistent with the experimental results. Simulations on the thin square-shaped isotropic superconducting films show that the threshold magnetic field for the flux avalanches increases with the angle between the applied field and the superconducting film-plane. In addition, the flux avalanche patterns change with the angular variation of the in-plane component of external magnetic field. When the in-plane magnetic field component is along the diagonal lines of the superconducting square, symmetric flux avalanche penetration patterns occur to the film.
COVID-19 Pandemic and the Use of Emergency Remote Teaching (ERT) Platforms: Lessons From a Nigerian University

Aim/Purpose: This study examines the use of the Emergency Remote Teaching (ERT) platform by undergraduates of the University of Ibadan, Nigeria, during the COVID-19 pandemic using the constructs of the UTAUT2 model. Five constructs of the UTAUT2 model were adopted to investigate the use of the ERT platform by undergraduates of the university. Background: The Coronavirus (COVID-19) outbreak disrupted academic activities in educational institutions, leading to an unprecedented school closure globally. In response to the pandemic, higher educational institutions adopted different initiatives aimed at ensuring the uninterrupted flow of their teaching and learning activities. However, there is little research on the use of ERT platforms by undergraduates in Nigerian universities. Methodology: The descriptive survey research design was adopted for the study. The multi-stage random sampling technique was used to select 334 undergraduates at the University of Ibadan, Nigeria, while a questionnaire was used to collect data from 271 students. Quantitative data were collected and analyzed using frequency counts, percentages, mean and standard deviation, Pearson Product Moment Correlation, and regression analysis. Contribution: The study contributes to understanding ERT use in the educational institutions of Nigeria – Africa’s most populous country. Furthermore, the study adds to the existing body of knowledge on how the UTAUT2 Model could explain the use of information technologies in different settings. Findings: Findings revealed that there was a positive significant relationship between habit, hedonic motivation, price value, and social influence on the use of ERT platforms by undergraduates. Hedonic motivation strongly predicted the use of ERT platforms by most undergraduates. Recommendations for Practitioners: As a provisional intervention in times of emergencies, the user interface, navigation, customization, and other aesthetic features of ERT platforms should be more appealing and enjoyable to ensure their optimum utilization by students. Recommendation for Researchers: More qualitative research is required on users’ satisfaction, concerns, and support systems for ERT platforms in educational institutions. Future studies could consider the use of ERT by students in different countries and contexts such as students participating in English as a Foreign Language (EFL) and the English for Speakers of other languages (ESOL) programs. Impact on Society: As society faces increased uncertainties of the next global pandemic, this article reiterates the crucial roles of information technology in enriching teaching and learning activities in educational institutions. Future Research: Future research should focus on how different technology theories and models could explain the use of ERT platforms at different educational institutions in other geographical settings and contexts.
Multi-messenger Constraints on Particle Acceleration in the Formation History of Galaxy Clusters

Galaxy Clusters are considered to be efficient containers of cosmic rays (CRs). In their formation history, CRs are accelerated by active galactic nuclei (AGNs) and cosmological shocks and turbulence and accumulated in the intra-cluster space. Diffuse radio emission found in massive clusters is important to probe the magnetic field and cosmic ray electrons, while the content of cosmic ray protons is highly uncertain. The variety seen in the radio emission suggests that the CR acceleration is closely related to the formation processes such as cluster mergers and mass accretion. We study the CR acceleration in galaxy clusters by modeling the multi-wavelength emission in various clusters with different formation histories. We use the so-called merger tree method to simulate the merger history of clusters. We particularly focus on the re-acceleration by merger-induced turbulence, since it is considered to be the dominant mechanism of the diffuse radio emission. We find that the combination of radio surveys and the stacking analysis of neutrino background can constrain the parameters in the re-acceleration model for the radio halos in galaxy clusters.
Effectiveness of herbal plants on rumen fermentation, methane gas emissions, in vitro nutrient digestibility, and population of protozoa

Background and Aim: Herbal plants have the potential to reduce the population of metagonic bacteria and protozoa due to the bioactive compound contained in herbal plants. This study aimed to evaluate the effect of herbal plant supplementation on rumen fermentation characteristics, methane (CH4) gas emissions, in vitro nutrient digestibility, and protozoan populations. Materials and Methods: This study consisted of two stages. Stage I involved determining the potential of herbal plants to increase total gas production (Orskov and McDonald methods) and reduce the protozoan population (Hristov method). Three potential herbs were selected at this stage and used in Stage II as supplements in the palm kernel cake (PKC)-based diet (30% herbal plants + 70% PKC). Proximate and Van Soest analyses were used to determine the chemical composition. In vitro dry matter digestibility (IVDMD), organic matter (IVOMD), and rumen fermentation characteristics were determined using Theodorous method. Conway microdiffusion was used to determine ammonia concentration (NH3). Gas chromatography was used to determine the total and partial volatile fatty acid production. Results: The results of the first stage showed that seven herbal plants (Moringa oleifera, Rhodomyrtus tomentosa, Clerodendron serratum, Curcuma longa Linn., Urena lobata, Uncaria, and Parkia timoriana) significantly differed in terms of total gas production (p < 0.05). Herbal plants can increase gas production and reduce protozoan populations. The highest total gas production was observed using P. timoriana, M. oleifera, and C. longa Linn. Moringa oleifera plants were the most effective in lowering protozoa population. In Stage 2, the supplementation of herbal plants in PKC-based-diet significantly increased IVDMD, that was ranged from 56.72% to 65.77%, IVOMD that was ranged from 52.10% to 59.54%, and NH3, that was ranged from 13.20 mM to 17.91 mM. Volatile fatty acid partial and total gas production potential and CH4 gas emissions were also significantly different from those of the control (p < 0.05). Conclusion: Supplementation of M. oleifera, C. longa Linn. , and P. timoriana in ruminant diet effectively increased total gas production, IVDMD percentage, and IVOMD, and reduced CH4 gas emissions and protozoa populations during rumen fermentation.
Fibroblast Growth Factor 23 in COVID-19: An Observational Study

Introduction: Fibroblast growth factor 23 (FGF23) belongs structurally to the endocrine FGF protein family, which also includes FGF19 and FGF21. In the past decade, FGF23 has emerged as a possible diagnostic, prognostic biomarker, and therapeutic target in several conditions. Data about COVID-19 and FGF23 is still limited, yet they suggest interesting interactions. Objective: In the present study, the levels of FGF23 were investigated in COVID-19 patients. These levels were also correlated with other inflammatory markers. Materials and methods: In our prospective observational study, blood samples were collected from 81 patients admitted with COVID-19 (31 males and 50 females). We analyzed the relation of serum FGF23 levels with biochemistry, total blood count, coagulation parameters, and demographic data. Results: The distribution of FGF23 serum levels according to sex and age (n28-40=8, n41-60=28, n65-75= 25, n75+=20) was similar. No significant correlation between FGF23 and any other biochemistry, total blood count, and coagulation parameter was revealed in the whole sample. Nevertheless, there was a variation in the results among different age groups. Conclusion: FGF23 levels seem to vary in symptomatic COVID-19 infection, but well-organized studies with larger numbers of patients in each group are needed to determine any reliable correlation between FGF23 and other laboratory parameters.
Acute Psychosis Related to Primary Hyperparathyroidism in a Patient With Bipolar Disorder

Primary hyperparathyroidism (PHPT) can cause hypercalcemia secondary to high parathyroid hormone secretion. Hyperparathyroidism- and hypercalcemia-related acute psychotic symptoms can be challenging to diagnose in patients with mental health-related disorders, and it should be considered a possible differential in these patients besides medications. It can sometimes be the first manifestation of the disease, and diagnosis can be challenging, especially in patients with a previous psychiatric history without checking their biochemistry profile. The hypercalcemia severity can vary from mild to severe, and signs and symptoms may also vary depending on the calcium levels. Hypercalcemia can cause neuropsychiatric dysfunction, and patients may present with confusion, agitation, delusions, and hallucinations. We present a case of a 54-year-old patient with a previous history of bipolar disorder and a recent diagnosis of depression and schizophreniform disorder, who presented to the emergency department with acute agitation, violent behavior, and disorientation. She was being managed by the community mental health team at a local behavioral health hospital for new onset psychosis over the past few months. She was refusing blood tests prior to hospital admission. Calcium level on laboratory tests was 3.54 mmol/l, and parathyroid hormone level was 45 pg/ml. She was managed with intravenous fluids initially, followed by zoledronic acid (4 mg intravenously over 15 minutes). She was then commenced on cinacalcet 30 mg twice daily initially, which was later increased to 60 mg twice daily. Ultrasound of the neck demonstrated a large left parathyroid mass, and she underwent left parathyroidectomy as an urgent outpatient. She has remained asymptomatic, and her psychiatry symptoms resolved following parathyroidectomy.
The most attractive companies in the labour market based on culture place of origin

This paper analyses the differences in the attractiveness of companies according to their country of origin. The aim is to expand knowledge about which characteristics make organisations more attractive to workers based on their place of origin (Anglo-Saxon, Northern-Central European, Mediterranean, Asian regions). In addition, it is analysed if the COVID-19 has caused changes in the elements that make up the attractiveness. The sample comprises the ranking published by the journal Actualidad Económica about the most attractive companies to work for in Spain, during 2013-21. The variables used in the ranking are: Talent-Management, Remuneration, Work-Environment, CSR and Training. Other control variables like geocultural area are used. For this purpose, an econometric model of unbalanced panel data with random effects is proposed. Results show there are differences in the assessment of professional attractiveness according to the companies' place of origin and culture. Remuneration and permanence in the ranking are the only variables which are relevant regardless of the culture. Talent Management, Working Environment and Training, size, and stock price influence Western countries unequally. The opposite occurs for SCR, which only affects Asian companies. Also, COVID-19 has affected unequally the assessment of the attractiveness of companies.
SMA and ALMA studies of protoplanetary disk formation around low-mass protostars

Abstract We report our systematic survey observations of protostellar sources with the SubMillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA). The purpose of our survey is to investigate formation mechanism of protoplanetary disks, precursors of planetary systems, out of ~1000 AU-scale protostellar envelopes surrounding the protostars. We found that in the early protostars (B335, NGC1333 IRAS 4B), the envelopes do not show significant rotating motions but infalling motions toward the central protostars. In more evolved protostars (L1527 IRS, L1448-mm, L1551 IRS 5), the envelopes are infalling and rotating with the conserved specific angular momenta (that is, v rot ∝ r −1). In most evolved sources (L1551 NE, TMC-1A, L1489 IRS) large-scale (≳100 AU) disks in Keplerian rotation or protoplanetary disks are evident. These results demonstrate a systematic evolutionary trend of envelope gas motions toward the disk formation.
Existence and characterization of best φ-approximations by linear subspaces

Abstract Given an Orlicz space L φ {L^{\varphi}} , we give very relaxed sufficient conditions on φ to ensure that there exists a best φ-approximation from any finite dimensional bounded linear subspace S ⊂ L φ {S\subset L^{\varphi}} . In addition, given an operator T, defined from L φ {L^{\varphi}} into itself, we give necessary and sufficient conditions on T to ensure that this is a best φ-approximation operator from a linear subspace S.
Subjective health and its predictors in leukaemia patients after bone marrow transplantation

Introduction The aims of the study were to assess subjective health and its psychological predictors in leukaemia patients after bone marrow transplantation (BMT). The theoretical rationale of the study was the functional model of health (FMH). Material and methods Participants in the study comprised 141 patients after BMT (61 women, 80 men) in the age range between 20 and 40 years, most of whom had secondary education. A standardized interview and 10-point rating scales of sense of health and sense of calmness were used to assess the subjective health. Their objective health was rated likewise on a 10-point scale by a physician-haematologist. The following questionnaires were used: CISS, SES, SOC-29, and STAI. Results The bone marrow transplantation patients’ sense of health was significantly lower than their objective health status assessed using objective medical parameters (respective means: 6.69, SD = 2.52, and 7.70, SD = 2.09, t = –4.59, df = 139, p < 0.001). According to the FMH as the study rationale, the patients’ subjective health depends on the effectiveness of their coping with illness, but also of personal resources including positive self- esteem and sense of coherence. Conclusions The subjective health of BMT patients was predicted by their objective health status (0.413) and by experienced stress (–0.285) counterbalanced by a strong sense of meaningfulness (0.244). Contemporary medicine can save leukaemia patients’ lives owing to the BMT, the recovery of their subjective health as a foundation of good functioning, which depends on psychological mechanisms, patient`s activity, and a supportive psychologist.
Guided Peer Review to Improve Students’ Essay Writing Competence: A Classroom Action Research

Feedback in oral as well as written form from both teachers and peers is commonly practiced in language learning at all levels. However, there are a limited number of researches referring to the effect of peer feedback on essay writing competence. Peer feedback can promote independent learning, yet, it may raise questions on its reliability. This study tries to reveal whether guided peer review gives any significant improvement on young adults' essay writing performance on their achievement test. Eight students of the One Year English Program at LIA Pramuka were involved in several sessions of essay writing activities, followed by peer correcting sessions guided by peer review checklist, and revising sessions. Pre-test and post-test were used to determine the improvement on such aspects of essay writing as organization, content, grammar, and vocabulary. It was found that most participants became more aware of how to write a well-organized and comprehensive essay although few still cannot perform well at the post-test. In contrast, this study revealed that peer checking cannot significantly help the students write well-structured sentences and choose appropriate diction. Since this study involves a small number of students, further research engaging more students and in more varied levels are encouraged.