Magneto-transport and localization in disordered systems with local superconductive attraction

Motivated by the intriguing features of the insulating regime close to an SIT, I carry out a systematic study of magnetoresistance, elucidating a variety of approach that influence it. In Chapter 2 I introduce a model of hard-core bosons on a two dimensional honeycomb lattice in a magnetic field, as motivated by recent experiments on structured films [38, 39]. This aims at explaining several key features observed in the activated magneto-transport in those experiments. Taking into account long range Coulomb interactions among the bosons, I study the crossover from strong to weak localization of those excitations and how it is affected by a magnetic field. An effective mobility edge in the excitation spectrum of the insulating Bose glass is identified as the (intensive) energy scale at which excitations become nearly delocalized. Within the forward scattering approximation in the bosonic hopping I find the effective mobility edge to oscillate periodically with the magnetic flux per plaquette [51]. Furthermore, I contrast the magnetoresistance in bosonic and fermionic systems, and thus show convincingly that the magneto-oscillations seen in experiments of SIT systems reflect the physics of localized electron pairs, i.e a Bose glass rather than a Fermi insulator. The bosonic magneto-oscillations start with an increase of the mobility edge (and thus of resistance) with applied flux, as opposed to the equivalent fermionic problem. The amplitude of the oscillations is much more substantial in bosons than in fermions. Bosons exhibit a single hump per flux period, while fermion characteristics undergo two humps. Those are identical for non-interacting fermions, but Coulomb correlations are shown to lead to systematic deviations from this statistical period doubling. In this approach, only bosonic degrees of freedom are considered. It thus cannot cover the wide range of fields often explored in experiments, where field-induced pair breaking processes certainly take place and are relevant. Therefore, in Chapter 3 I introduce a microscopic model taking both bosonic and fermionic degrees of freedom into account. This model is then used to study the magnetic field driven crossover from pair to single electron regimes and the corresponding resistive transport. This study is motivated by the above mentioned experiments observing a strong magnetoresistance peak on the insulating side of the SIT which reflects that crossover. Assuming Mott variable range hopping transport, the pair-to-single crossover in transport is driven by the crossover in the characteristic temperature scale TM governing the stretched exponential growth of the resistance R(T) for pairs and single electrons. Within this work, I consider a system of electrons on a square lattice, subject to strong onsite disorder, a local pairing attraction, a magnetic field, and nearest neighbor hopping. The tuning parameter, the magnetic field, enters both by a (spatially) isotropic Zeeman depairing term and an anisotropic orbital effect proportional to the perpendicular component of the field incorporated via the complex phase of the hoppings. I found that the former leads to a strong effect on the density of state which causes and dominates the crossover, and thus the magnetoresistance peak. The orbital effect captures the effect of the quantum interference of different types of carriers. It further enhances the peak as the field orientation changes. I also discuss the effect of including Coulomb interactions into this theory. Having pointed out the peculiarity of two dimensional disordered systems which are marginal in terms of single-particle localization, and in view of our finding of the effective mobility edge above, I address the question of whether Coulomb interactions can give rise to a genuine mobility edge in electronic systems in two dimensions. In Chapter 4 with Coulomb interactions being treated at a more quantum level (but still approximately) within a Hartree-Fock treatment, I carry out a numerical study aiming at addressing the possibility of an interaction-induced delocalization effect. This setting focuses on the multiplicity of electron species, or valley degeneracy, that Punnoose and Finkel'stein [11, 52] predicted to cause delocalization in two dimensional interacting electron system. As I will discuss, by looking at the density-density correlation function, the system with multiple species behaves differently from the system with single species. In the former, the two-stage scale-dependent behavior of the correlation function reflects the scale-dependent resistance predicted in Punnoose and Finkel'stein's renormalization group equations

Finding Voice in the Academy through Yellow Storytelling: An Asian American Autoethnography on Suffering in Higher Education

ABSTRACT Higher education institutions in the United States (U.S.) were founded for a select segment of the population, i.e. white Christian men from upper socioeconomic classes (Thelin, 2011). Research shows the policies, pedagogies, and practices created for use within majority populations and dominant cultures are not as beneficial or effective for individuals from underrepresented backgrounds. As the U.S. becomes more diverse and college enrollment among diverse students increases, higher education institutions need to identify more holistic approaches and investigate alternative methods to better serve these populations. This dissertation is a response to that need. In order to offer other alternatives, educators must acknowledge suffering in the origins of U.S. higher education and its replication of structural oppression. Institutions of higher education have recreated the wheels of suffering in U.S. society for generations by not acknowledging suffering or detailing how it affects students and employees; we are unskilled at mindfulness and lack Tiếp Hiện, which is translated as interbeing (Hanh, 2008). This research study employs the pedagogical tradition of the Zen Buddhist path and applies the practice of mindfulness and interbeing. Through critical Zen autoethnographic methodological approach, personal stories are shared and reflected on as a source for those who participate in the academy to potentially find alternative methods to heal

Nursing Students\u27 Awareness About Effective Teamwork and Related Factors

This study surveyed the awareness level of nursing students about the effectiveness of teamwork and related factors. At Hong Bang International University (HIU), teamwork training for nursing students at HIU has been applied but it has been difficult for all students to achieve high results and confidence in practicing teamwork skills. The effectiveness of self-study and group activities depends on many factors. The effectiveness of teaching approaches has not been measured and has needed to be addressed to result in the best learning experience for students. The results of this study provided recommendations to improve the quality of training as well as to inform the successful design of an educational program regarding teamwork. A descriptive, cross-sectional design was used. A questionnaire was administered to 129 nursing students who were in their third and final year in the Bachelor of Nursing Program from Hong Bang International University. Participants were 101females and 28 males. The questionnaire Teamwork skill of Saigon University (Huyen, 2010) included 33 items, which were rated on a 5-point Likert scale. Reliability of this instrument for this study was .95. The use of learner-centered methods in the college has shifted the focus of activity from the teacher to the students to develop learner autonomy and independence. This has been considered a challenge for nursing students because they are not only learning at school but also in clinical settings. Therefore, nursing students\u27 awareness about the role of effective teamwork is very important so they can work together to develop their learning quality. Nurse educators could use this study’s results to improve teaching strategies regarding teamwork knowledge and skills for nursing students in Vietnam

Perspectives on English Language Teaching and Learning during COVID-19 Pandemic

Since its outbreak two years ago, the COVID-19 pandemic has affected the world-wide education systems, leading to school closures in many countries as well as the changes in the whole educational procedures. In order to reassure parents, students and other involved leaders, there has been a rapid shift from face-to-face education to emergency online teaching. English language teaching and learning is accordingly an integral flow in this stream of online process, which then motivates educators and researchers to have a further look at the effects of COVID-19 on digital language acquisition. Hence, this study aims to explore both teachers’ and students’ perspectives on English language teaching and learning during COVID-19 pandemic. The findings, from both quantitative and qualitative data, reveal that all the participants as learners agreed upon the positive influences of online English learning in terms of skill development. Besides, they also considered the flexibility of class schedules and a variety of online assignments as the biggest advantages while bothering with some disadvantages such as internet/technical and health problems. As for English language teachers, speaking skill is the most challenging skill to help students; moreover, some of their concerns include difficulties in class management, online interaction, facilitation, assessment and digital literacy. Nevertheless, they confirmed the advantages of online resources, new knowledge of technological issues and development of learner autonomy. Overall, the research appeals more support from the university officials to improve the quality of online English teaching and learning; in addition, it contributes to make both teachers’ and learners’ voices heard during the coronavirus quarantine. Keywords: Pandemic, Online, English, Teaching, Learning, Perspectives, Development. DOI: 10.7176/JEP/13-34-01 Publication date: December 31st 202

Impact of health insurance on healthcare utilisation patterns in Vietnam: a survey-based analysis with propensity score matching method

Objectives The study aims to evaluate the impact of the Revised Health Insurance Law 2014 on the utilisation of outpatient and inpatient care services, healthcare services utilisation at different levels of providers, types of providers and types of visits across different entitlement groups. Design/setting Secondary data from two waves of the Vietnam Household Living Standard Survey (VHLSS) 2016, VHLSS 2014 were used. A cross-sectional study applying propensity score matching was conducted. Participants A total of 4900 individuals who reported using healthcare services are analysed. Outcomes measure Numbers of outpatient and inpatient visits, frequency of healthcare service utilisation at commune health stations, district hospitals, provincial hospitals, public and private health facilities, number of visits at health facility for medical treatment and health checks per year. Results The result indicates that health insurance (HI) policy increased the number of outpatient visits for the enrolled between 0.87 and 1.29. The greatest impact was found on participants of heavily subsidised health insurance (HSHI) programmes with 1.29 visits per person per year. Similarly, an increase between 0.08 and 0.16 in the number of inpatient admissions was because of participation in HI. With regard to type of healthcare providers, the study found that participation in HI has the most effect on the use of healthcare services at district hospitals. However, the study demonstrated that the impacts of HI on the increase in the frequency of visiting commune health stations, number of visits at the provincial hospital for HSHI groups, and number of visits at health facilities for health check and consultation were sensitive to unobserved characteristics. Conclusion Our findings imply that policy-makers in Vietnam could continue expanding health insurance coverage to increase access to healthcare services for citizens, especially vulnerable groups. In addition, the government should draw more attention to primary healthcare level

An investigation of seasonal variations in the microbiota of milk, feces, bedding, and airborne dust

Objective The microbiota of dairy cow milk varies with the season, and this accounts in part for the seasonal variation in mastitis-causing bacteria and milk spoilage. The microbiota of the cowshed may be the most important factor because the teats of a dairy cow contact bedding material when the cow is resting. The objectives of the present study were to determine whether the microbiota of the milk and the cowshed vary between seasons, and to elucidate the relationship between the microbiota. Methods We used 16S rRNA gene amplicon sequencing to investigate the microbiota of milk, feces, bedding, and airborne dust collected at a dairy farm during summer and winter. Results The seasonal differences in the milk yield and milk composition were marginal. The fecal microbiota was stable across the two seasons. Many bacterial taxa of the bedding and airborne dust microbiota exhibited distinctive seasonal variation. In the milk microbiota, the abundances of Staphylococcaceae, Bacillaceae, Streptococcaceae, Microbacteriaceae, and Micrococcaceae were affected by the seasons; however, only Micrococcaceae had the same seasonal variation pattern as the bedding and airborne dust microbiota. Nevertheless, canonical analysis of principle coordinates revealed a distinctive group comprising the milk, bedding, and airborne dust microbiota. Conclusion Although the milk microbiota is related to the bedding and airborne dust microbiota, the relationship may not account for the seasonal variation in the milk microbiota. Some major bacterial families stably found in the bedding and airborne dust microbiota, e.g., Staphylococcaceae, Moraxellaceae, Ruminococcaceae, and Bacteroidaceae, may have greater influences than those that varied between seasons

AUTHENTIC ASSESSMENT: A REAL LIFE APPROACH TO WRITING SKILL DEVELOPMENT

 Since assessment is an indispensable part of education, curriculum makers, educators and teachers have engaged in an ongoing discussion of how to address student performance. A variety of assessments including both short-term and long-term ones can be applied during or at the end of the learning process. Among such types, authentic assessment is a prominent approach. This paper is going to advocate authentic assessments as it fosters students' growth and teachers' pedagogical strategies. In addition, it helps to reach the goals of educational practices through the authenticity of equity and innovation when students actively seek their own ways to appreciate what they have learnt. Particularly, in a writing skills class, learners can take this opportunity to improve step by step their own proficiency in the use of written words. The paper, hence, discusses how authentic assessment can be applied to develop college students' writing through classroom observation and a set of semi-structured interviews. The result of the study revealed that using authentic assessment is an effective strategy for enhancing students’ interest in writing process and writing task fulfillment. Students would find it easier to become skillful writers at their English levels. The study, therefore, recommends more uses of authentic assessment in teaching writing skills as well as in teaching and learning the English language in general

Do Technical Barriers to Trade Measures Affect Vietnam’s Tea Exports? Evidence from the Gravity Model

This paper explores how technical barriers to trade (TBT) affect Vietnam’s tea exports to 55 importing countries from 2001 to 2019. We use the gravity model with different estimation methods: ordinary least square (OLS), fixed-effect (FE), and random effect (RE) to estimate the impact of TBT on Vietnam’s tea exports. The results show that although GDP, population, distance, tariff, and participation in World Trade Organization (WTO) are crucial factors, the TBT measures imposed by these importing countries have significantly negative impacts on Vietnam’s tea exports. Our findings reveal that while a 1% increase in the cumulative TBT measures imposed by developing countries decreases Vietnam's tea export by 0.341%, the figure for developed countries is 1.308%

THE IMPACT OF INNOVATION ON ECONOMIC GROWTH: THE SPILLOVER EFFECT OF FOREIGN DIRECT INVESTMENT

Purpose of the study: Innovation is seen as the key to improving quality and productivity, thereby promoting competition and economic growth. This study analyzes the impact of innovation on economic growth through various measures, such as research and development spending, the number of researchers, number of patents as well as trademark registrations. Research results are evidence to recommend policies for intellectual-based economic growth. Methodology: Literature review and empirical analysis conducted in the study. The empirical method is a two-step System Generalize Methods of Moments (GMM), aiming at reliable results. Accessing the World Bank Database, research data from 64 developed and developing countries are collected from 2006 to 2014. Main Findings: The empirical findings show that innovation plays a crucial contribution in promoting economic growth, similar to national openness and government spending on education. This study also finds a positive impact on foreign investment flows and their spillover role in enhancing the correlation between innovation and economic growth. Applications of this study: The findings of this study focus on the contributions of innovation, foreign direct investment inflows, and other macro factors that can be enforced to improve economic growth by policymakers. Novelty/Originality of this study: The study uses different measures of innovation, including inputs such as the number of researchers, research and development expenditure, and outputs as the number of patents and number of trademark registrations. Empirical findings are found consistently, thus confirming that innovation is very important for economic growth. The study also shows convincing evidence confirming the positive contribution of foreign direct investment as well as its spillover effect on innovation and economic growth