Design reliability goal developed from small sample

Sampling distributions, constructed by Monte Carlo simulation are used in hardware development to establish a design reliability goal, to place a confidence coefficient on reliability estimates, and to determine whether sample stress/strength data demonstrate a specified reliability at a specified confidence level

Public health and economic costs of investigating a suspected outbreak of Legionnaires' disease.

This paper provides one of the first assessments of the burden of both the public health investigation and the economic costs associated with an apparent outbreak of Legionnaires' disease (LD) in South East London. In addition to epidemiological, microbiological and environmental investigations, we collected data on the staff time and resources committed by the 11 main organizations responsible for managing the outbreak. Of the overall estimated costs of 455,856 pounds, only 14% (64,264 pounds) was spent on investigation and control of the outbreak compared with 86% (391,592 pounds) spent on the hospital treatment of the patients. The time and money spent on public health services in this investigation appear to represent good value for money considering the potential costs of a major outbreak, including the high case-fatality rate in LD generally and the high health-care costs. Further research is needed to determine optimum strategies for the cost-effective use of health system resources in investigations of LD. Whether the threshold for investigation of cases should be based on observed incidence rates or the cost-effectiveness of investigations, or both, should be debated further

Carbon-Carbon bond forming reactions of organotransition metal enolate complexes

Abstract -Metal enolates play an important role in stereoselective organic synthesis. Their chemistry is affected profoundly by the metal counterion associated with the enolate fragment. In order to expand the potential of replacing main group with transition metal moieties in such species, methods have been developed for the synthesis of a number of stable, characterizable "late" transition metal ql-(C)-enolate complexes having the general structure LM-CH2COR (M = Mo, W, Re). The chemistry of these materials (e.g., functional transformations of the organic carbonyl group, transfer of the enolate moietry to organic substrates such as aldehydes and alkynes) has been investigated. The scope and mechanisms of the enolate reactions will be discussed in detail. The reaction of organic enolates with carbon electrophiles (e.g., alkyl halides, organic carbonyl compounds) gives rise to compounds containing new carbon-carbon bonds; reaction with heteroatom electrophiles results in the formation of oxidized products? There has been much interest recently in developing methods for carrying out these transformations with high stereoselectivity.3 Historically, most enolate research has focused on salts involving alkali metal anions. More recently, research efforts have been extended to enolates associated with organic cations, main group metals, and transition metals. In the transition metal area, enolates involving the so-called "early" metals (to the left of chromium, molybdenum and tungsten) have seen extensive investigationi4 in general these complexes have 0-bonded structures A in Scheme 1. This paper describes the synthesis and chemistry of middle-and late transition metal enolates, which have seen less investigation. It was our hope that such species would be more likely to have Cbound structure B, and also to react with both electrophilic and non-electrophilic species (e.g., by insertion rather than nucleophile-electrophile mechanisms). SYNTHESIS, CHARACTERIZATION AND FUNCTIONAL GROUP TRANSFORMATIONS OF TUNGSTEN AND MOLYBDENUM ENOLATES The well-known nucleophilic anionic metal salts5 Na[(qS-C5R5)(C0)3M] (M = Mo, W, R=H, Me), on treatment with a-chloroketones and esters, provide good yields of enolates 1 -8, as shown in Scheme 2. These are thermally stable complexes that may be isolated by conventional chromatographic and recrystallization methods; they have been characterized fully by elemental analysis and spectroscopic techniques. Preparation of these materials on a multi-gram scale in a one-pot procedure is possible by treatment of W(CO)6 or Mo(C0)6 with NaCp, followed by addition of the a-chlorocarbonyl compound to the resulting metal anion solution. The stability of the tungsten-carbon bond in tungsten ester enolates, fiist suggested several years ago by the work of Green and his coworkers6, has allowed us to carry out a wide range of transformations on the organic carbonyl group. Thus the reactions shown in Scheme 3 proceed in good yield, and lead to stable tungsten enolates containing ester, amide and even carboxylic acid and acid chloride functionality

Pandemic (H1N1) 2009 virus outbreak in a school in London, April-May 2009: an observational study

On 29 April 2009, an imported case of pandemic (H1N1) 2009 virus infection was detected in a London school. As further cases, pupils and staff members were identified, school closure and mass prophylaxis were implemented. An observational descriptive study was conducted to provide an insight into the clinical presentation and transmission dynamics in this setting. Between 15 April and 15 May 2009, 91 symptomatic cases were identified: 33 were confirmed positive for pandemic (H1N1) 2009 virus infection; 57 were tested negative; in one the results were unavailable. Transmission occurred first within the school, and subsequently outside. Attack rates were 2% in pupils (15% in the 11–12 years age group) and 17% in household contacts. The predominant symptoms were fever (97%), respiratory symptoms (91%), and sore throat (79%). Limited spread in the school may have been due to a combination of school closure and mass prophylaxis. However, transmission continued through household contacts to other schools

Adaptation of the difficulty level in an infant-robot movement contingency study

19th International Workshop of Physical Agents (WAF). Madrid (22-23 Noviembre 2018)ABSTRACT: This paper presents a personalized contingency feedback adaptation system that aims to encourage infants aged 6 to 8 months to gradually increase the peak acceleration of their leg movements. The ultimate challenge is to determine if a socially assistive humanoid robot can guide infant learning using contingent rewards, where the reward threshold is personalized for each infant using a reinforcement learning algorithm. The model learned from the data captured by wearable inertial sensors measuring infant leg movement accelerations in an earlier study. Each infant generated a unique model that determined the behavior of the robot. The presented results were obtained from the distributions of the participants' acceleration peaks and demonstrate that the resulting model is sensitive to the degree of differentiation among the participants; each participant (infant) should have his/her own learned policy.This work was supported by NSF award 1706964 (PI: Smith, Co-PI: Matarić). In addition, this work was developed during an international mobility program at the University of Southern California being also partially funded by the European Union ECHORD++ project (FP7-ICT-601116), the LifeBots project (TIN2015-65686-C5) and THERAPIST project (TIN2012-38079)

High incidence of primary tuberculosis

An usually high rate of both tuberculosis infection and active disease is reported in 11 of 38 nursery children in contact with a case of smear positive pulmonary tuberculosis, emphasising the susceptibility of young children to this disease. This report also underlines some important principles in case finding and disease control.