Tunable coupling to a mechanical oscillator circuit using a coherent feedback network

We demonstrate a fully cryogenic microwave feedback network composed of modular superconducting devices connected by transmission lines and designed to control a mechanical oscillator coupled to one of the devices. The network features an electromechanical device and a tunable controller that coherently receives, processes and feeds back continuous microwave signals that modify the dynamics and readout of the mechanical state. While previous electromechanical systems represent some compromise between efficient control and efficient readout of the mechanical state, as set by the electromagnetic decay rate, the tunable controller produces a closed-loop network that can be dynamically and continuously tuned between both extremes much faster than the mechanical response time. We demonstrate that the microwave decay rate may be modulated by at least a factor of 10 at a rate greater than $10^4$ times the mechanical response rate. The system is easy to build and suggests that some useful functions may arise most naturally at the network-level of modular, quantum electromagnetic devices.Comment: 11 pages, 6 figures, final published versio

Antimicrobials for Preterm Birth Prevention: An Overview

Objective. Preterm birth (PTB) remains a major cause of neonatal morbidity and mortality. The association between PTB and infection is clear. The purpose of this report is to present a focused review of information on the use of antibiotics to prevent PTB. Methods. We performed a search of the PubMed database restricted to clinical trials or meta-analyses published in English from 1990 through May 2011 using keywords “antibiotics or antimicrobials” and “preterm.” Results. The search yielded 67 abstracts for review. We selected 31 clinical trials (n = 26) or meta-analysis (n = 5) for further full-text review. Discussion of each eligible clinical trial, its specific inclusion criteria, antibiotic regimen used, and study results are presented. Overall, trials evaluating antibiotic treatment to prevent preterm birth have yielded mixed results regarding any benefit. Conclusion. Routine antibiotic prophylaxis is not recommended for prevention of preterm birth

On the number of representations providing noiseless subsystems

This paper studies the combinatoric structure of the set of all representations, up to equivalence, of a finite-dimensional semisimple Lie algebra. This has intrinsic interest as a previously unsolved problem in representation theory, and also has applications to the understanding of quantum decoherence. We prove that for Hilbert spaces of sufficiently high dimension, decoherence-free subspaces exist for almost all representations of the error algebra. For decoherence-free subsystems, we plot the function $f_d(n)$ which is the fraction of all $d$-dimensional quantum systems which preserve $n$ bits of information through DF subsystems, and note that this function fits an inverse beta distribution. The mathematical tools which arise include techniques from classical number theory.Comment: 17 pp, 4 figs, accepted for Physical Review

Group life insurance in Kuwait : problems and prospects

The Kuwaiti government obliged firms to cover part of employee's risks through legislation in 1965 and 1977. Employers should cover risks as death or job injury due to or during work. This had affected the group life insurance (GLI) market. The thesis examines the economics of this market. Problem of choosing the right life table with respect to Kuwaiti mortality rates is tested. The efficiency of using English life tables to estimate mortality rates in Kuwait GLI market is examined. The effects of GLI underwriters on the market are investigated. The Social Security Services (SSS) are offered for Kuwaitis only, Non-Kuwaitis face more economical insecurity than Kuwaitis do. Therefore, the demand for employees' group investment plan to cover future security facing Kuwaiti and non-Kuwaiti workers, in particular, is also considered. The thesis suggests several methods to solve the problems facing the Kuwait GLI market. Kuwaiti Mortality rates are estimated using data from both the Social Security Association (SSA) and a sample of term group life insurees to be compared with English and American life tables. Methods of avoiding lack of information, adverse selection, and moral hazard in Kuwait GLI market are proposed. Finally, the advantages of introducing group investment plan are examined, and it was shown that these could alleviate SSS problems. Use of group investment plan should reduce the cost of the SSS for Kuwaitis, secure part of Non-Kuwaitis risks, and assist insurers to avoid or reduce their economic problems

Standarized radiological hazard analysis for a broad based operational safety program

The Radiological hazard Analysis (RHA) Manual provides a methodology and detailed guidance for systematic analysis of radiological hazards over a broad spectrum of program functions, housed in a wide variety of facilities. Radiological programs at LANL include: research and experimentation; routine materials operations; production; non-destructive examination or testing; isotope and machine produced radiations; chemistry; and metallurgy. The RHA permits uniform evaluation of hazard types over a range of several orders of magnitude of hazard severity. The results are used to estimate risk, evaluate types and level or resource allocations, identify deficiencies, and plan corrective actions for safe working environments. 2 refs

Randomised trial of glutamine, selenium, or both, to supplement parenteral nutrition for critically ill patients

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