Yang-Mills Instantons with Lorentz Violation

An analysis is performed of instanton configurations in pure Euclidean Yang-Mills theory containing small Lorentz-violating perturbations that maintain gauge invariance. Conventional topological arguments are used to show that the general classification of instanton solutions involving the topological charge is the same as in the standard case. Explicit solutions are constructed for general gauge invariant corrections to the action that are quadratic in the curvature. The value of the action is found to be unperturbed to lowest order in the Lorentz-violating parameters.Comment: 16 page

Developing Clinical Faculty Understanding of Interprofessional Education: An Inter-institutional, Interprofessional Approach

Introduction: The call for increasing interprofessional education requires institutional support for educators in the clinical environment. Innovative ideas, such as partnering with multiple universities and programs to facilitate an interprofessional workshop, have the opportunity to reach a broader group of clinical educators. The purpose of this study was to examine the attitude of healthcare professionals towards interprofessional learning, familiarity with concepts of interprofessional teaching, and interprofessional practice, and to examine the influence of an interprofessional faculty development workshop on participant familiarity with concepts of interprofessional teaching and learning. Methods: The occupational therapy, physical therapy, and physician assistant programs from two universities collaborated to implement an all-day inter-institutional, interprofessional clinical faculty development workshop. Community clinical educators who participated in the event were surveyed pre- and post-workshop to examine their attitude, readiness, and knowledge of interprofessional learning and teaching. Using the revised version of the Readiness of Interprofessional Learning Scale, the following subscales were measured and analyzed: 1) Teamwork and Collaboration, 2) Negative Professional Identity, 3) Positive Professional Identity, and 4) Roles and Responsibilities. Results: Forty-three participants representing six different healthcare professions completed pre- and post-course surveys. Forty-four percent reported participating in interprofessional education. Overall, the attendees reported the value of the workshop as a 4.6 on a 5.0 point Likert scale, with 5.0 being the highest rating. Self-reported familiarity of the fundamental concepts of interprofessional teaching, interprofessional practice, and interprofessional education improved up to 32% following participation in the workshop. The highest increase in familiarity was in the area of knowledge of interprofessional practice and education. Participants reported high levels of agreement about the value of teamwork, collaboration, and positive professional identity. Conclusion: Integrating the Core Competencies for Interprofessional Collaborative Practice into educational programs and clinical practice can facilitate improved understanding of professional roles and improved collaborative practice

The geometry of thermodynamic control

A deeper understanding of nonequilibrium phenomena is needed to reveal the principles governing natural and synthetic molecular machines. Recent work has shown that when a thermodynamic system is driven from equilibrium then, in the linear response regime, the space of controllable parameters has a Riemannian geometry induced by a generalized friction tensor. We exploit this geometric insight to construct closed-form expressions for minimal-dissipation protocols for a particle diffusing in a one dimensional harmonic potential, where the spring constant, inverse temperature, and trap location are adjusted simultaneously. These optimal protocols are geodesics on the Riemannian manifold, and reveal that this simple model has a surprisingly rich geometry. We test these optimal protocols via a numerical implementation of the Fokker-Planck equation and demonstrate that the friction tensor arises naturally from a first order expansion in temporal derivatives of the control parameters, without appealing directly to linear response theory

High-fidelity single-shot readout for a spin qubit via an enhanced latching mechanism

The readout of semiconductor spin qubits based on spin blockade is fast but suffers from a small charge signal. Previous work suggested large benefits from additional charge mapping processes, however uncertainties remain about the underlying mechanisms and achievable fidelity. In this work, we study the single-shot fidelity and limiting mechanisms for two variations of an enhanced latching readout. We achieve average single-shot readout fidelities > 99.3% and > 99.86% for the conventional and enhanced readout respectively, the latter being the highest to date for spin blockade. The signal amplitude is enhanced to a full one-electron signal while preserving the readout speed. Furthermore, layout constraints are relaxed because the charge sensor signal is no longer dependent on being aligned with the conventional (2, 0) - (1, 1) charge dipole. Silicon donor-quantum-dot qubits are used for this study, for which the dipole insensitivity substantially relaxes donor placement requirements. One of the readout variations also benefits from a parametric lifetime enhancement by replacing the spin-relaxation process with a charge-metastable one. This provides opportunities to further increase the fidelity. The relaxation mechanisms in the different regimes are investigated. This work demonstrates a readout that is fast, has one-electron signal and results in higher fidelity. It further predicts that going beyond 99.9% fidelity in a few microseconds of measurement time is within reach.Comment: Supplementary information is included with the pape

Intramolecular and intermolecular contributions to the barriers for rotation of methyl groups in crystalline solids: Electronic structure calculations and solid state NMR relaxation measurements

The rotation barriers for 10 different methyl groups in five methyl-substituted phenanthrenes and three methyl-substituted naphthalenes were determined by ab initio electronic structure calculations, both for the isolated molecules and for the central molecules in clusters containing 8–13 molecules. These clusters were constructed computationally using the carbon positions obtained from the crystal structures of the eight compounds and the hydrogen positions obtained from electronic structure calculations. The calculated methyl rotation barriers in the clusters (Eclust) range from 0.6 to 3.4 kcal/mol. Solid-state 1H NMR spin–lattice relaxation rate measurements on the polycrystalline solids gave experimental activation energies (ENMR) for methyl rotation in the range from 0.4 to 3.2 kcal/mol. The energy differences Eclust – ENMR for each of the ten methyl groups range from −0.2 kcal/mol to +0.7 kcal/mol, with a mean value of +0.2 kcal/mol and a standard deviation of 0.3 kcal/mol. The differences between each of the computed barriers in the clusters (Eclust) and the corresponding computed barriers in the isolated molecules (Eisol) provide an estimate of the intermolecular contributions to the rotation barriers in the clusters. The values of Eclust – Eisol range from 0.0 to 1.0 kcal/mol

Intramolecular and intermolecular contributions to the barriers for rotation of methyl groups in crystalline solids: Electronic structure calculations and solid state NMR relaxation measurements

The rotation barriers for 10 different methyl groups in five methyl-substituted phenanthrenes and three methyl-substituted naphthalenes were determined by ab initio electronic structure calculations, both for the isolated molecules and for the central molecules in clusters containing 8–13 molecules. These clusters were constructed computationally using the carbon positions obtained from the crystal structures of the eight compounds and the hydrogen positions obtained from electronic structure calculations. The calculated methyl rotation barriers in the clusters (Eclust) range from 0.6 to 3.4 kcal/mol. Solid-state 1H NMR spin–lattice relaxation rate measurements on the polycrystalline solids gave experimental activation energies (ENMR) for methyl rotation in the range from 0.4 to 3.2 kcal/mol. The energy differences Eclust – ENMR for each of the ten methyl groups range from −0.2 kcal/mol to +0.7 kcal/mol, with a mean value of +0.2 kcal/mol and a standard deviation of 0.3 kcal/mol. The differences between each of the computed barriers in the clusters (Eclust) and the corresponding computed barriers in the isolated molecules (Eisol) provide an estimate of the intermolecular contributions to the rotation barriers in the clusters. The values of Eclust – Eisol range from 0.0 to 1.0 kcal/mol

Perceived agency mediates the link between the narcissistic subtypes and self-esteem

a b s t r a c t a r t i c l e i n f o Grandiose and vulnerable narcissism share some core features (e.g., entitlement, self-absorption) but differ in other important ways (e.g., self-esteem). To reconcile these differing characteristics, we predicted that differences in perceived agency mediate the association between narcissistic subtypes and differences in selfesteem. One hundred college students completed self-report measures of grandiose narcissism, vulnerable narcissism, explicit global self-esteem, and perceived agency. As predicted, grandiose narcissism was positively associated with agency and self-esteem, whereas vulnerable narcissism was negatively associated with agency and self-esteem. Perceived agency also mediated the associations between each narcissistic subtype and selfesteem. Furthermore, a partial correlation showed that when controlling for agency, the previously null correlation between measures of grandiose and vulnerable narcissism became significantly positive. These findings indicate that agency serves as a primary differentiator between the narcissistic subtypes

Spinors, Inflation, and Non-Singular Cyclic Cosmologies

We consider toy cosmological models in which a classical, homogeneous, spinor field provides a dominant or sub-dominant contribution to the energy-momentum tensor of a flat Friedmann-Robertson-Walker universe. We find that, if such a field were to exist, appropriate choices of the spinor self-interaction would generate a rich variety of behaviors, quite different from their widely studied scalar field counterparts. We first discuss solutions that incorporate a stage of cosmic inflation and estimate the primordial spectrum of density perturbations seeded during such a stage. Inflation driven by a spinor field turns out to be unappealing as it leads to a blue spectrum of perturbations and requires considerable fine-tuning of parameters. We next find that, for simple, quartic spinor self-interactions, non-singular cyclic cosmologies exist with reasonable parameter choices. These solutions might eventually be incorporated into a successful past- and future-eternal cosmological model free of singularities. In an Appendix, we discuss the classical treatment of spinors and argue that certain quantum systems might be approximated in terms of such fields.Comment: 12 two-column pages, 3 figures; uses RevTeX