1,859 research outputs found
Field-Tuning of the electron and hole populations in the ruthenate Bi_3Ru_3O_11
Experiments on the Hall coefficient R_H and heat capactity C reveal an
unusual, compensated electronic ground state in the ruthenate Bi_3Ru_3O_11. At
low temperature T, R_H decreases linearly with magnetic field |H| for fields
larger than the field scale set by the Zeeman energy. The results suggest that
the electron and hole populations are tuned by H in opposite directions via
coupling of the spins to the field. As T is decreased below 5 K, the curve
C(T)/T vs. T^2 shows an anomalous flattening consistent with a rapidly growing
Sommerfeld parameter \gamma(T). We discuss shifts of the electron and hole
chemical potentials by H to interpret the observed behavior of R_H.Comment: 5 pages, 6 figures, reference adde
Disorder-induced phonon self-energy of semiconductors with binary isotopic composition
Self-energy effects of Raman phonons in isotopically disordered
semiconductors are deduced by perturbation theory and compared to experimental
data. In contrast to the acoustic frequency region, higher-order terms
contribute significantly to the self-energy at optical phonon frequencies. The
asymmetric dependence of the self-energy of a binary isotope system on the concentration of the heavier isotope mass x can be explained by
taking into account second- and third-order perturbation terms. For elemental
semiconductors, the maximum of the self-energy occurs at concentrations with
, depending on the strength of the third-order term. Reasonable
approximations are imposed that allow us to derive explicit expressions for the
ratio of successive perturbation terms of the real and the imaginary part of
the self-energy. This basic theoretical approach is compatible with Raman
spectroscopic results on diamond and silicon, with calculations based on the
coherent potential approximation, and with theoretical results obtained using
{\it ab initio} electronic theory. The extension of the formalism to binary
compounds, by taking into account the eigenvectors at the individual
sublattices, is straightforward. In this manner, we interpret recent
experimental results on the disorder-induced broadening of the TO (folded)
modes of SiC with a -enriched carbon sublattice.
\cite{Rohmfeld00,Rohmfeld01}Comment: 29 pages, 9 figures, 2 tables, submitted to PR
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Strategic distortions in analyst forecasts in the presence of short-term institutional investors
We document that analysts cater to short - term investors by issuing optimistic target prices. Catering dominates among analysts at brokers without an investment banking arm as they face lower reputational cost. The market does not see through the analyst catering activity and their forecasts lead to temporary stock overpricing that short - term institutional investors exploit to offload their holdings to retail traders. We also report evidence consistent with catering brokers being rewarded with more future trades channelled through them. Our study identifies a new source of conflicts of interest in analyst research originating from the ownership composition of a stock
Comparative Chromosome Maps of Neotropical Rodents Necromys lasiurus and Thaptomys nigrita (Cricetidae) Established by ZOO-FISH
This work presents chromosome homology maps between Mus musculus (MMU) and 2 South American rodent species from the Cricetidae group: Necromys lasiurus (NLA, 2n = 34) and Thaptomys nigrita (TNI, 2n = 52), established by ZOO-FISH using mouse chromosome-specific painting probes. Extending previous molecular cytogenetic studies in Neotropical rodents, the purpose of this work was to delineate evolutionary chromosomal rearrangements in Cricetidae rodents and to reconstruct the phylogenetic relationships among the Akodontini species. Our phylogenetic reconstruction by maximum parsimony analysis of chromosomal characters confirmed one consistent clade of all Neotropical rodents studied so far. In both species analyzed here, we observed the syntenic association of chromosome segments homologous to MMU 8/13, suggesting that this chromosome form is a synapomorphic trait exclusive to Neotropical rodents. Further, the previously described Akodontini-specific syntenic associations MMU 3/18 and MMU 6/12 were observed in N. lasiurus but not in T. nigrita, although the latter species is considered a member of the Akodontini tribe by some authors. Finally, and in agreement with this finding, N. lasiurus and Akodon serrensis share the derived fission of MMU 13, which places them as basal sister clades within Akodontini. Copyright (C) 2011 S. Karger AG, Base
Inclusivity in Action: Interprofessional Curricula Integrates Two-Step Question for Sex and Gender Identity
Background: Identifcation of sex and gender identity is the first step to inclusive care for sex and gender minorities, and studies have shown that health care providers may make heteronormative assumptions about sex and gender. Implemented in 2007, the Jefferson Health Mentors Program (JHMP) involves firstand second-year students from couple and family therapy, human genetics and genetic counseling, medical laboratory sciences, medicine, nursing, occupational therapy, pharmacy, physical therapy, and physician assistant studies. In the First assignment, 140 student teams complete a comprehensive questionnaire, the Individual Life and Wellness History with their Health Mentor. Health Mentors live with one or more chronic conditions and range in age from 27 to 95 years old, with the majority over age 50. Interprofessional education where students learn from, with, and about each other is an ideal place for students to be exposed to the sex and gender two-step question.
Objectives: To describe our experience with 713 students involved in the JHMP asking the two-step sex and gender question.
Methods/Research: In Fall 2018, the two-step sex and gender question was added to the questionnaire. The module evaluation included both a quantitative and a qualitative question to gather student feedback on the inclusion of the two-step sex and gender questions. The qualitative responses were reviewed for themes, and the authors came to consensus.
Conclusions/Impact: Common themes included student appreciation of the importance of the questions; confusion of the Health Mentors with the questions; student perception of generational differences, and student teams having no issues with the questions. No Health Mentors dropped out of the program after the First assignment, other than those who dropped out for health related reasons. Interprofessional education can provide a venue for normalizing the two-step sex and gender question.https://jdc.jefferson.edu/sexandgenderhealth/1000/thumbnail.jp
Confirmation of Parity Violation in the Gamma Decay of
This paper reports measurements using the technique of On Line Nuclear
Orientation (OLNO) which reexamine the gamma decay of isomeric Hf and specifically the 501 keV 8 -- 6
transition. The irregular admixture of E2 to M2/E3 multipolarity in this
transition, deduced from the forward-backward asymmetry of its angular
distribution, has for decades stood as the prime evidence for parity mixing in
nuclear states. The experiment, based on ion implantation of the newly
developed mass-separated Hf beam at ISOLDE, CERN into an
iron foil maintained at millikelvin temperatures, produces higher degrees of
polarization than were achieved in previous studies of this system. The value
found for the E2/M2 mixing ratio, = -0.0324(16)(17), is in close
agreement with the previous published average value = - 0.030(2), in
full confirmation of the presence of the irregular E2 admixture in the 501 keV
transition. The temperature dependence of the forward-backward asymmetry has
been measured over a more extended range of nuclear polarization than
previously possible, giving further evidence for parity mixing of the 8 and 8 levels and the deduced E2/M2 mixing ratio.Comment: 28 pages, 9 figures, accepted for publication in Physical Review
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