13,547 research outputs found
Spin relaxation and spin Hall transport in 5d transition-metal ultrathin films
The spin relaxation induced by the Elliott-Yafet mechanism and the extrinsic
spin Hall conductivity due to the skew-scattering are investigated in 5d
transition-metal ultrathin films with self-adatom impurities as scatterers. The
values of the Elliott-Yafet parameter and of the spin-flip relaxation rate
reveal a correlation with each other that is in agreement with the Elliott
approximation. At 10-layer thickness, the spin-flip relaxation time in 5d
transition-metal films is quantitatively reported about few hundred nanoseconds
at atomic percent which is one and two orders of magnitude shorter than that in
Au and Cu thin films, respectively. The anisotropy effect of the Elliott-Yafet
parameter and of the spin-flip relaxation rate with respect to the direction of
the spin-quantization axis in relation to the crystallographic axes is also
analyzed. We find that the anisotropy of the spin-flip relaxation rate is
enhanced due to the Rashba surface states on the Fermi surface, reaching values
as high as 97% in 10-layer Hf(0001) film or 71% in 10-layer W(110) film.
Finally, the spin Hall conductivity as well as the spin Hall angle due to the
skew-scattering off self-adatom impurities are calculated using the Boltzmann
approach. Our calculations employ a relativistic version of the
first-principles full-potential Korringa-Kohn-Rostoker Green function method
A novel function for the Caenorhabditis elegans torsin OOC-5 in nucleoporin localization and nuclear import.
Torsin proteins are AAA+ ATPases that localize to the endoplasmic reticular/nuclear envelope (ER/NE) lumen. A mutation that markedly impairs torsinA function causes the CNS disorder DYT1 dystonia. Abnormalities of NE membranes have been linked to torsinA loss of function and the pathogenesis of DYT1 dystonia, leading us to investigate the role of the Caenorhabditis elegans torsinA homologue OOC-5 at the NE. We report a novel role for torsin in nuclear pore biology. In ooc-5-mutant germ cell nuclei, nucleoporins (Nups) were mislocalized in large plaques beginning at meiotic entry and persisted throughout meiosis. Moreover, the KASH protein ZYG-12 was mislocalized in ooc-5 gonads. Nups were mislocalized in adult intestinal nuclei and in embryos from mutant mothers. EM analysis revealed vesicle-like structures in the perinuclear space of intestinal and germ cell nuclei, similar to defects reported in torsin-mutant flies and mice. Consistent with a functional disruption of Nups, ooc-5-mutant embryos displayed impaired nuclear import kinetics, although the nuclear pore-size exclusion barrier was maintained. Our data are the first to demonstrate a requirement for a torsin for normal Nup localization and function and suggest that these functions are likely conserved
Tool-less Double Sided Board Retainer
Disclosed is a retainer that allows retention of two daughter circuit boards on either side of a main circuit board. The retention device allows the daughter boards to align with each other, minimizing the space required on the main board
Strong spin-orbit fields and Dyakonov-Perel spin dephasing in supported metallic films
Spin dephasing by the Dyakonov-Perel mechanism in metallic films deposited on
insulating substrates is revealed, and quantitatively examined by means of
density functional calculations combined with a kinetic equation. The
surface-to-substrate asymmetry, probed by the metal wave functions in thin
films, is found to produce strong spin-orbit fields and a fast Larmor
precession, giving a dominant contribution to spin decay over the Elliott-Yafet
spin relaxation up to a thickness of 70 nm. The spin dephasing is oscillatory
in time with a rapid (sub-picosecond) initial decay. However, parts of the
Fermi surface act as spin traps, causing a persistent tail signal lasting 1000
times longer than the initial decay time. It is also found that the decay
depends on the direction of the initial spin polarization, resulting in a
spin-dephasing anisotropy of 200% in the examined cases
Percutaneous pulmonary valve implantation alters electrophysiologic substrate
BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is firstâline therapy for some congenital heart disease patients with right ventricular outflow tract dysfunction. The hemodynamics improvements after PPVI are well documented, but little is known about its effects on the electrophysiologic substrate. The objective of this study is to assess the shortâ and mediumâterm electrophysiologic substrate changes and elucidate postprocedure arrhythmias. METHODS AND RESULTS: A retrospective chart review of patients undergoing PPVI from May 2010 to April 2015 was performed. AÂ total of 106 patients underwent PPVI; most commonly these patients had tetralogy of Fallot (n=59, 55%) and pulmonary insufficiency (n=60, 57%). The median followâup time was 28Â months (7â63Â months). PreâPPVI, 25 patients (24%) had documented arrhythmias: nonsustained ventricular tachycardia (NSVT) (n=9, 8%), frequent premature ventricular contractions (PVCs) (n=6, 6%), and atrial fibrillation/flutter (AF/AFL) (n=10, 9%). PostâPPVI, arrhythmias resolved in 4 patients who had NSVT (44%) and 5 patients who had PVCs (83%). New arrhythmias were seen in 16 patients (15%): 7 NSVT, 8 PVCs, and 1 AF/AFL. There was resolution at mediumâterm followâup in 6 (86%) patients with newâonset NSVT and 7 (88%) patients with newâonset PVCs. There was no difference in QRS duration preâPPVI, postâPPVI, and at mediumâterm followâup (P=0.6). The median corrected QT lengthened immediately postâPPVI but shortened significantly at midterm followâup (P<0.01). CONCLUSIONS: PPVI reduced the prevalence of NSVT. The majority of postimplant arrhythmias resolve by 6Â months of followâup
Higher Education Professionals Navigating Anti-Immigration Policy for Undocumented Students
Higher education professionals are critical to undocumented studentsâ educational success as their access to higher education is heavily dependent on being able to interpret and navigate policies. This study presents an analysis of policies that impact higher education access for undocumented students coupled with a qualitative case study that examines how anti-immigration policy affects the experiences of higher education professionals who worked directly with undocumented students in the state of Indiana. The authors help readers understand the experiences and challenges facing these âpathfindersâ as they attempt to navigate the mazes of federal, state, and institutional policy to help their undocumented students
Student Success Through Leadership Self-efficacy: A Comparison of International and Domestic Students
There is scarce research that examines the leadership experiences of international students on campus. Leadership capacity and efficacy are important indicators of success in higher education and are linked to important academic, career, and life benefits, such as career and leadership aspirations, work performance, the ability to cope and overcome stereotypes, and the adaptation to and persistence in the face of challenging situations. This quantitative study focuses on international studentsâ confidence in their leadership abilities while studying in a foreign country and system in comparison with their domestic student peers. Findings suggest that college campuses and higher education professionals need to do a better job at engaging their international students in leadership opportunities while being culturally relevant
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