4,300 research outputs found
Novel Quantum Criticality in Two Dimensional Topological Phase transitions
Topological quantum phase transitions intrinsically intertwine
self-similarity and topology of many-electron wave-functions, and divining them
is one of the most significant ways to advance understanding in condensed
matter physics. Our focus is to investigate an unconventional class of the
transitions between insulators and Dirac semimetals whose description is beyond
conventional pseudo relativistic Dirac Hamiltonian. At the transition without
the long-range Coulomb interaction, the electronic energy dispersion along one
direction behaves like a relativistic particle, linear in momentum, but along
the other direction it behaves like a non-relativistic particle, quadratic in
momentum. Various physical systems ranging from TiO-VO
heterostructure to organic material -(BEDT-TTF) I under
pressure have been proposed to have such anisotropic dispersion relation. Here,
we discover a novel quantum criticality at the phase transition by
incorporating the 1/r long-range Coulomb interaction. Unique interplay between
the Coulomb interaction and electronic critical modes enforces not only the
anisotropic renormalization of the Coulomb interaction but also marginally
modified electronic excitation. In connection with experiments, we investigate
several striking effects in physical observables of our novel criticality.Comment: 12 pages + 31 pages, 5 figures, 2 tables, published versio
Topological Phase Transitions in Line-nodal Superconductors
Fathoming interplay between symmetry and topology of many-electron
wave-functions has deepened understanding of quantum many body systems,
especially after the discovery of topological insulators. Topology of electron
wave-functions enforces and protects emergent gapless excitations, and symmetry
is intrinsically tied to the topological protection in a certain class. Namely,
unless the symmetry is broken, the topological nature is intact. We show novel
interplay phenomena between symmetry and topology in topological phase
transitions associated with line-nodal superconductors. The interplay may
induce an exotic universality class in sharp contrast to that of the
phenomenological Landau-Ginzburg theory. Hyper-scaling violation and emergent
relativistic scaling are main characteristics, and the interplay even induces
unusually large quantum critical region. We propose characteristic experimental
signatures around the phase transitions in three spatial dimensions, for
example, a linear phase boundary in a temperature-tuning parameter
phase-diagram.Comment: 4 + 23 pages, 7 figures, 1 table; the first two authors contributed
equally to this wor
International Student Transitions After Yale (iSTAY): Career Development and Post-Graduation Transition Program for International Students
International mobility is a significant aspect of internationalization with international student enrollment increasing exponentially on U.S campuses. A major motivator for studying in the U.S. is the correlation between international education and employment prospects. Through pursuing quality education in a globalized context, students, along with many other stakeholders, strive to be competitive in the globalizing workplace and accomplish social mobility through gaining intercultural competence and cultural capital. However, a review of literature and research indicates a void in scholarly understanding and comprehensive programs for international student support in career development and post-graduation transitions. The research demonstrated a need for career development resources and practices that is reflective of international student-specific challenges through a collaborative structure between international student services and career offices.
Yale University, an elite, Ivy, research university in New Haven, Connecticut is no exception to these trends and challenges. A needs assessment of current programs and institutional visibility of international students revealed a need for a comprehensive program that promotes post-graduation international student success. The proposed program, International Student Transitions at Yale (iSTAY) will use the experiential learning theory as a foundation to create a program that helps students develop career efficacy while building the capacity for self-authorship in their personal and professional plans after graduation. The academic year-long program for international undergraduate students will not only equip students with practical tools to get a job in the U.S., but also create a space for students to reflect upon their cross-cultural experience and international identity and be able to approach the transition from student to professional in a holistic and experiential way
Reducing Confusion about Grounded Theory and Qualitative Content Analysis: Similarities and Differences
Although grounded theory and qualitative content analysis are similar in some respects, they differ as well; yet the differences between the two have rarely been made clear in the literature. The purpose of this article was to clarify ambiguities and reduce confusion about grounded theory and qualitative content analysis by identifying similarities and differences in the two based on a literature review and critical reflection on the authors’ own research. Six areas of difference emerged: (a) background and philosophical base, (b) unique characteristics of each method, (c) goals and rationale of each method, (d) data analysis process, (e) outcomes of the research, and (f) evaluation of trustworthiness. This article provides knowledge that can assist researchers and students in the selection of appropriate research methods for their inquiries
Activation of two types of brain glutamate dehydrogenase isoproteins by gabapentin
AbstractThe stimulatory effects of gabapentin on the activities of two types of glutamate dehydrogenase (GDH) isoproteins homogeneously purified from bovine brain have been studied at various conditions. When the effects of different gabapentin concentrations on GDH activities were studied in the direction of reductive amination of 2-oxoglutarate with NADPH as a coenzyme, a marked activation was observed for both isoproteins, whereas both isoproteins showed activation to a lesser extent with NADH as a coenzyme. Stimulatory effects of gabapentin on GDH activities in the direction of the oxidative deamination of glutamate were also observed, but to a much lesser extent than reductive amination. There were big differences between the two GDH isoproteins in their sensitivity to the action of gabapentin. The largest activation was observed with GDH II when NADPH was used as a coenzyme. Half-maximal stimulation was reached at around 1.5 mM. Gabapentin relieved the inhibition of GDH isoproteins by GTP and this resulted in an increase in the apparent activation by gabapentin in the presence of GTP. 2-Oxoglutarate was found to give rise to high substrate inhibition and gabapentin reduced the substrate inhibition in the presence of 0.2 mM NADH. Since there are neurodegenerative disorders in which GDH activity is decreased, the therapeutic modulation of the activity of this enzyme may be clinically useful
Impact of the surrounding built environment on energy consumption in mixed-use building
While a mixture of residential and non-residential uses in urban development has advantages in reducing transportation energy consumption and improving efficiency of land utilization, the patterns of energy consumption in mixed-use buildings are largely unknown. To understand associations between the built environment and energy consumption and to find effective strategies for energy saving, this study aims to examine how the gas and electricity energy consumption of mixed-use properties is influenced by the characteristics of the immediate surroundings of the building as well as by the building's attributes. The sample for this study is 22,109 mixed-use buildings in Seoul, Korea and the main source of outcome is electricity and gas energy consumption data retrieved from the open system of building data in 2015 and 2016. The regression results showed that a higher proportion of non-residential uses in mixed-use buildings was positively associated with higher electricity consumption overall but that it reduced gas energy use during the winter. In particular, increased restaurant and service use significantly influenced electricity consumption in the buildings. With regard to surrounding built environment, higher impervious surfaces and dense development near the buildings increased the electricity consumption of the buildings but it reduced gas energy consumption. Our results imply that, through the mediating effects of UHIs, the built environment characteristics of immediate surroundings may have indirect effects on energy consumption in mixed-use buildings
Case of chronic indolent pheochromocytoma that caused medically controlled hypertension but treatment-resistant diabetes mellitus
No abstract available
Feature Engineering Using File Layout for Malware Detection
Malware detection on binary executables provides a high availability to even
binaries which are not disassembled or decompiled. However, a binary-level
approach could cause ambiguity problems. In this paper, we propose a new
feature engineering technique that use minimal knowledge about the internal
layout on a binary. The proposed feature avoids the ambiguity problems by
integrating the information about the layout with structural entropy. The
experimental results show that our feature improves accuracy and F1-score by
3.3% and 0.07, respectively, on a CNN based malware detector with realistic
benign and malicious samples.Comment: 2pages, no figures, This manuscript was presented in the poster
session of The Annual Computer Security Applications Conference (ACSAC) 202
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