Searching for confined modes in graphene channels: The variable phase method

Copyright © 2012 American Physical SocietyUsing the variable phase method, we reformulate the Dirac equation governing the charge carriers in graphene into a nonlinear first-order differential equation from which we can treat both confined-state problems in electron waveguides and above-barrier scattering problems for arbitrary-shaped potential barriers and wells, decaying at large distances. We show that this method agrees with a known analytic result for a hyperbolic secant potential and go on to investigate the nature of more experimentally realizable electron waveguides, showing that when the Fermi energy is set at the Dirac point, truly confined states are supported in pristine graphene. In contrast to exponentially decaying potentials, we discover that the threshold potential strength at which the first confined state appears is vanishingly small for potentials decaying at large distances as a power law; but nonetheless, further confined states are formed when the strength and spread of the potential reach a certain threshold.Millhayes Foundation (DAS)Engineering and Physical Sciences Research Council: EPSRC (CAD)EU FP7 ITN SpinoptronicsFP7 IRSES project SPINMETFP7 IRSES project TerACaNFP7 IRSES project ROBOCO

Oral Challenge with Trimethoprim-Sulfamethoxazole in Patients with “Sulfa” Antibiotic Allergy

Letter to the Edito

Readiness for PENicillin allergy testing: Perception of Allergy Label (PEN-PAL) Survey

Clinical Implications: Patients reporting penicillin allergy believe their allergy to be permanent, would take penicillins if tested negative, but are rarely referred for penicillin testing, leading to differential antibiotic utilization

Penicillin allergy labels drive perioperative prophylactic antibiotic selection in orthopedic procedures

'Clinical Communications' [No abstract

MAGNETIC RECORDER FOR NUCLEAR PULSE APPLICATION. Final Report Covering Period: June 5, 1959 to June 5, 1960

An analog recording technique was investigated in which pulses from a scintillation counter are stretched to a width compatible with the bandwidth of the recorder. Three types of playback systems were considered, i.e., unequalized velocity, equalized velocity, and flux sensitive playback. The results of the three systems were found to be comparable. Loss in resolution in the process was primarily due to nonuniformities in magnetic tape properties and maintenance of an adequate head to tape contact. Instrumental line widths of the order of 3% were achieved using equipment of moderate cost. (For preceding period see ARF- 1151-5.) (auth

The Semileptonic Decays D→π(ρ)eνD\to \pi(\rho) e \nu and B→π(ρ)eνB\to \pi (\rho) e \nu from QCD Sum Rules

We investigate the semileptonic decays of B and D mesons into $\pi$ and $\rho$ mesons, respectively, by means of QCD sum rules. We find that for the vector formfactors involved the pole dominance hypothesis is valid to good accuracy with pole masses in the expected range. Pole dominance, however, does not apply to the axial formfactors which results in specific predictions for the predominant polarization of the $\rho$ meson and the shape of the lepton spectrum. For the total decay rates we find $\Gamma (\bar B^0 \to \pi^+ e^- \bar\nu) = (5.1\pm 1.1)\,|V_{ub}|^2\, 10^{12}\,{\rm s^{-1}}$, $\Gamma ( D^0 \to \pi^- e^+ \nu) = (8.0\pm 1.7)\,|V_{cd}|^2\, 10^{10}\,{\rm s^{-1}}$, $\Gamma (\bar B^0 \to \rho^+ e^- \bar\nu) = (1.2\pm 0.4\,)\,|V_{ub}|^2\, 10^{13}\,{\rm s^{-1}}$ and $\Gamma (D^0 \to \rho^- e^+\nu) = (2.4\pm 0.7)\,|V_{cd}|^2\, 10^{9}\,{\rm s^{-1}}$.Comment: 23 pages, 12 figures included as uu-encoded file, needs REVTEX, TUM--T31--39/9

Quantum-Limited Measurement and Information in Mesoscopic Detectors

We formulate general conditions necessary for a linear-response detector to reach the quantum limit of measurement efficiency, where the measurement-induced dephasing rate takes on its minimum possible value. These conditions are applicable to both non-interacting and interacting systems. We assess the status of these requirements in an arbitrary non-interacting scattering based detector, identifying the symmetries of the scattering matrix needed to reach the quantum limit. We show that these conditions are necessary to prevent the existence of information in the detector which is not extracted in the measurement process.Comment: 13 pages, 1 figur

Feasibility and Preliminary Effectiveness of the Homework Intervention Strategy (eHIS) Program to Enhance Male Condom Use: Research Protocol.

BACKGROUND: Although condoms are effective in reducing the risk of sexually transmitted infections (STIs) and unintended pregnancy, they are still often not used consistently and correctly. Negative impact on sensation and pleasure, ruining the mood, causing problems with maintaining erection, and condom slippage or breakage are some of the reasons given by men explaining why they do not want to use condoms. Although many interventions promoting condom use exist, some of them delivered online are complex and time- and resource-intensive. The Homework Intervention Strategy (eHIS) program, adapted from the existing face-to-face Kinsey Institute Homework Intervention Strategy (KIHIS) program, aims to address these issues by encouraging men to focus on sensation and pleasure when trying different types of condoms and lubricants in a low-pressure situation (on their own, without a partner present). OBJECTIVE: The objectives of this study are to assess the feasibility, acceptability, and users' engagement with the eHIS program, its preliminary effectiveness in increasing condom use frequency and consistency, as well as the feasibility of the program's evaluation approach, including choice of measures and participant recruitment and retaining strategies (primary outcomes). Secondary outcomes include condom use experience, condom use attitudes, condom use self-efficacy, condom use errors and problems, and condom fit-and-feel. All of these will be analyzed in the context of participants' demographics, sexual history, and previous condom use. METHODS: The study has a pre-post-test, within-subjects design. Men aged 18 to 69 and living in the United Kingdom are recruited through posters, leaflets, social media, and emails. Study participants are asked to complete T1 (baseline) measures before entering the eHIS website. After completing the T1 measures, they can order a free condoms and lubricants kit and have access to the eHIS website for 4 weeks. During that time they are asked to practice using different types of condoms and lubricants on their own in a no-pressure situation. Following T1, participants are asked to complete the T2 and T3 measures at 4 and 10 weeks, respectively. RESULTS: Data collection for the study is completed. Data analysis is in progress and is expected to be completed by February 2018. CONCLUSIONS: This brief, home-based, self-guided program may lead to increased consistent and correct condom use. Online delivery can make the program an easily accessible and low-cost health promotion intervention, which has the potential to reach a wide and diverse audience. If results of the current study show the program's feasibility and preliminary effectiveness in changing condom use related outcomes, a larger scale randomized controlled trial (RCT) will be conducted. TRIAL REGISTRATION: Research Registry: researchregistry2325; http://www.researchregistry.com/browse-the-registry.html# home/registrationdetails/58da6cad1d7ab0314337d076/ (Archived by WebCite at http://www.webcitation.org/6vXs6S9XW)

Technological Devices in the Archives: A Policy Analysis

Doing research in the archive is the cornerstone of humanities scholarship. Various archives institute policies regarding the use of technological devices, such as mobile phones, laptops, and cameras in their reading rooms. Such policies directly affect the scholars as the devices mediate the nature of their interaction with the source materials in terms of capturing, organizing, note taking, and record keeping for future use of found materials. In this paper, we present our analysis of the policies of thirty archives regarding the use of technology in their reading rooms. This policy analysis, along with data from interviews of scholars and archivists, is intended to serve as a basis for developing mobile applications for assisting scholars in their research activities. In this paper we introduce an early prototype of such a mobile application— AMTracker.Informatio