Spontaneous and stimulated emission tuning characteristics of a Josephson junction in a microcavity

We have investigated theoretically the tuning characteristics of a Josephson junction within a microcavity for one-photon spontaneous emission and for one-photon and two-photon stimulated emission. For spontaneous emission, we have established the linear relationship between the magnetic induction and the voltage needed to tune the system to emit at resonant frequencies. For stimulated emission, we have found an oscillatory dependence of the emission rate on the initial Cooper pair phase difference and the phase of the applied field. Under specific conditions, we have also calculated the values of the applied radiation amplitude for the first few emission maxima of the system and for the first five junction-cavity resonances for each process. Since the emission of photons can be controlled, it may be possible to use such a system to produce photons on demand. Such sources will have applications in the fields of quantum cryptography, communications and computation

Excitation of local magnetic moments by tunnelling electrons

The advent of milli-kelvin scanning tunneling microscopes (STM) with inbuilt magnetic fields has opened access to the study of magnetic phenomena with atomic resolution at surfaces. In the case of single atoms adsorbed on a surface, the existence of different magnetic energy levels localized on the adsorbate is due to the breaking of the rotational invariance of the adsorbate spin by the interaction with its environment, leading to energy terms in the meV range. These structures were revealed by STM experiments in IBM Almaden in the early 2000's for atomic adsorbates on CuN surfaces. The experiments consisted in the study of the changes in conductance caused by inelastic tunnelling of electrons (IETS, Inelastic Electron Tunnelling Spectroscopy). Manganese and Iron adatoms were shown to have different magnetic anisotropies induced by the substrate. More experiments by other groups followed up, showing that magnetic excitations could be detected in a variety of systems: e.g. complex organic molecules showed that their magnetic anistropy was dependent on the molecular environment, piles of magnetic molecules showed that they interact via intermolecular exchange interaction, spin waves were excited on ferromagnetic surfaces and in Mn chains, and magnetic impurities have been analyzed on semiconductors. These experiments brought up some intriguing questions: the efficiency of magnetic excitations was very high, the excitations could or could not involve spin flip of the exciting electron and singular-like behavior was sometimes found at the excitation thresholds. These facts called for extended theoretical analysis; perturbation theories, sudden-approximation approaches and a strong coupling scheme successfully explained most of the magnetic inelastic processes. In addition, many-body approaches were also used to decipher the interplay between inelasComment: Review article to appear in Progress of Surface Scienc

The identification and analysis of making-do waste: insights from two Brazilian construction sites

Making-do has been pointed out as an important category of waste in the construction industry. It refers to a situation in which a task starts or continues without having available all the inputs required for its completion, such as materials, machinery, tools, personnel, external conditions, and information. By contrast, the literature points out that improvisation is a ubiquitous human practice even in highly structured business organizations, and plays an important role when rules and methods fail. The aim of this paper is to provide some insights on the nature of making-do as a type of waste, based on two exploratory case studies carried out on construction sites. The main contributions of this research work are concerned with the identification of different categories of making-do and its main causes. This paper also discusses some strategies for reducing making-do on construction sites

The impact of due process and disruptions on emergency medicine education in the United States

INTRODUCTION: Academic Emergency Medicine (EM) departments are not immune to natural disasters, economic or political forces that disrupt a training program\u27s operations and educational mission. Due process concerns are closely intertwined with the challenges that program disruption brings. Due process is a protection whereby an individual will not lose rights without access to a fair procedural process. Effects of natural disasters similarly create disruptions in the physical structure of training programs that at times have led to the displacement of faculty and trainees. Variation exists in the implementation of transitions amongst training sites across the country, and its impact on residency programs, faculty, residents and medical students. METHODS: We reviewed the available literature regarding due process in emergency medicine. We also reviewed recent examples of training programs that underwent disruptions. We used this data to create a set of best practices regarding the handling of disruptions and due process in academic EM. RESULTS: Despite recommendations from organized medicine, there is currently no standard to protect due process rights for faculty in emergency medicine training programs. Especially at times of disruption, the due process rights of the faculty become relevant, as the multiple parties involved in a transition work together to protect the best interests of the faculty, program, residents and students. Amongst training sites across the country, there exist variations in the scope and impact of due process on residency programs, faculty, residents and medical students. CONCLUSION: We report on the current climate of due process for training programs, individual faculty, residents and medical students that may be affected by disruptions in management. We outline recommendations that hospitals, training programs, institutions and academic societies can implement to enhance due process and ensure the educational mission of a residency program is given due consideration during times of transition

The Response of Paroxysmal Supraventricular Tachycardia to Overdrive Atrial and Ventricular Pacing:

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75015/1/j.1540-8167.1993.tb01227.x.pd

Further Insight into Mechanisms of Ventricular Tachycardia from the Clinical Electrophysiology Laboratory

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72003/1/j.1540-8167.1991.tb01319.x.pd

Red cell specifications for blood group matching in patients with haemoglobinopathies: An updated systematic review and clinical practice guideline from the International Collaboration for Transfusion Medicine Guidelines

Summary: Red blood cell (RBC) antigen matching beyond ABO and RhD is commonly recommended for patients with sickle cell disease (SCD) and thalassaemia. We present an updated systematic literature review to inform evidence‐based guidelines on RBC matching. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to develop recommendations. Six new observational studies (4 prospective, 2 retrospective) were identified. The six studies reported on 583 patients in total, including cross‐over designs, with sample sizes from 10 to 343. Studies were heterogeneous, utilising varying degrees of RBC matching and different definitions for ‘extended’ matching. All reported on alloimmunisation. One study reported on molecular matching. The reported prevalence of alloimmunisation using limited matching was 0%–50% and with extended matching was 0%–24%. Eighty‐two patients were alloimmunised before study entry. The risk of bias across studies was moderate to critical. The guideline panel recommends that ABO, RhDCcEe, and K‐compatible RBCs are selected for individuals with SCD and thalassaemia, even in the absence of alloantibodies, and that RBCs which are antigen‐negative to already existing clinically significant antibodies are chosen. There is a need for comparative research to define the benefit, impact, cost‐effectiveness, and feasibility of extended RBC matching strategies to prevent alloimmunisation