Fault section identification and location on a distribution feeder using travelling waves

This paper describes how the fault generated travelling waves detected in the current signals at a single location on a distribution feeder can be used for fault section identification and location. The method identifies the fault section and the probable location of the fault by comparing the relative distance of each "peak" in the high frequency current signals to the known reflection points in the distribution feeder. The probable fault location is then used within a transient power system simulator that models the actual network. The resulting simulated current waveforms are then cross-correlated against the signal captured on the real network. If the estimated fault location is correct, the high frequency signatures in the simulated waveform will be similar to that of the measured waveforms and the cross-correlation value will be a high positive value. Simulation studies using PSCAD/EMTDC and analysis using cross-correlation technique suggest that the method described can accurately locate a fault on a distribution feeder using measurement at a single location

The concise measurement of clinical communication skills: Validation of a short scale

Objective There is a lack of brief rating scales for the reliable assessment of psychotherapeutic skills, which do not require intensive rater training and/or a high level of expertise. Thus, the objective is to validate a 14-item version of the Clinical Communication Skills Scale (CCSS-S). Methods Using a sample of N = 690 video-based ratings of role-plays with simulated patients, we calculated a confirmatory factor analysis and an exploratory structural equation modeling (ESEM), assessed convergent validities, determined inter-rater reliabilities and compared these with those who were either psychology students, advanced psychotherapy trainees, or experts. Results Correlations with other competence rating scales were high (rs > 0.86–0.89). The intraclass correlations ranged between moderate and good [ICC(2,2) = 0.65–0.80], with student raters yielding the lowest scores. The one-factor model only marginally replicated the data, but the internal consistencies were excellent (α = 0.91–95). The ESEM yielded a two-factor solution (Collaboration and Structuring and Exploration Skills). Conclusion The CCSS-S is a brief and valid rating scale that reliably assesses basic communication skills, which is particularly useful for psychotherapy training using standardized role-plays. To ensure good inter-rater reliabilities, it is still advisable to employ raters with at least some clinical experience. Future studies should further investigate the one- or two-factor structure of the instrument.Peer Reviewe

The Kepler Pixel Response Function

Kepler seeks to detect sequences of transits of Earth-size exoplanets orbiting Solar-like stars. Such transit signals are on the order of 100 ppm. The high photometric precision demanded by Kepler requires detailed knowledge of how the Kepler pixels respond to starlight during a nominal observation. This information is provided by the Kepler pixel response function (PRF), defined as the composite of Kepler's optical point spread function, integrated spacecraft pointing jitter during a nominal cadence and other systematic effects. To provide sub-pixel resolution, the PRF is represented as a piecewise-continuous polynomial on a sub-pixel mesh. This continuous representation allows the prediction of a star's flux value on any pixel given the star's pixel position. The advantages and difficulties of this polynomial representation are discussed, including characterization of spatial variation in the PRF and the smoothing of discontinuities between sub-pixel polynomial patches. On-orbit super-resolution measurements of the PRF across the Kepler field of view are described. Two uses of the PRF are presented: the selection of pixels for each star that maximizes the photometric signal to noise ratio for that star, and PRF-fitted centroids which provide robust and accurate stellar positions on the CCD, primarily used for attitude and plate scale tracking. Good knowledge of the PRF has been a critical component for the successful collection of high-precision photometry by Kepler.Comment: 10 pages, 5 figures, accepted by ApJ Letters. Version accepted for publication

Cumulative and temporal associations between antimicrobial prescribing and community-associated <i>Clostridium difficile</i> infection:population-based case-control study using administrative data

Background. Community-associated (CA) Clostridium difficile infection (CDI) is a major public health problem. This study estimates the magnitude of the association between temporal and cumulative prescription of antimicrobials in primary care and CA-CDI. CA-CDI is defined as cases without prior hospitalisation in the previous 12 weeks who were either tested outside of hospital or tested within 2 days of admission to hospital. Methods. Three National patient level datasets –covering CDI cases, community prescriptions and hospitalisations were linked by the NHS Scotland unique patient identifier, the community health index, CHI. All validated cases of CDI from August 2010 to July 2013 were extracted and up to six population-based controls were matched to each case from the CHI register for Scotland. Statistical analysis used conditional logistic regression. Results. 1446 unique cases of CA-CDI were linked with 7964 age, sex and location matched controls. Cumulative exposure to any antimicrobial in the previous 6 months has a monotonic dose-response association with CA-CDI. Individuals with excess of 28 defined daily doses (DDD) to any antimicrobial (19.9% of cases) had an odds ratio (OR)=4.4 (95% CI:3.4-5.6) compared to those unexposed. Individuals exposed to 29+ DDD of high risk antimicrobials (cephalosporins, clindamycin co-amoxiclav, or fluoroquinolones) had an OR=17.9 (95% CI:7.6-42.2). Elevated CA-CDI risk following high risk antimicrobial exposure was greatest in the first month (OR=12.5 (8.9-17.4)) but was still present 4-6 months later (OR=2.6 (1.7-3.9)). Cases exposed to 29+DDD had prescription patterns more consistent with repeated therapeutic courses, using different antimicrobials, than long term prophylactic use. Conclusions. This analysis demonstrated temporal and dose-response associations between CA-CDI risk and antimicrobials with an impact of exposure to high risk antimicrobials remaining 4-6 months later

Evaluating the Impact of Business Service Expertise and Business Links on the Performance of SMEs in England

The last decade has seen a growing body of research on information-intensive business service firms. These are companies that supply expertise and knowledge which are considered to add value to the output of their clients. This paper explores the impact of business service expertise provided via business link on the performance, profitability and competitiveness of client companies. The authors use a unique survey of small and medium-sized enterprises (SMEs) in England as well as case studies of individual firms. It is possible to identify a positive impact of business service expertise on client performance, but difficult and perhaps impossible to isolate such impacts from other variables. Employment as an impact measure is problematic as redundancy rather than recruitment may result from a consultancy project. The best measure is improvements in profitability, but not all consultancy projects will impact on this variable. The department of trade and industry needs to be extremely careful that a concern for evaluation of business link companies does not inadvertently produce a situation in which the evaluation process determines the way in which a business link company identifies and deals with its clients.

Estimating Population Cause-Specific Mortality Fractions from in-Hospital Mortality: Validation of a New Method

Working in Mexico and using vital registration data, Chris Murray and colleagues achieved encouraging results with a new method to estimate population cause-specific mortality fractions

A non-randomised controlled pilot study of clinical pharmacist collaborative intervention for community dwelling patients with COPD

UK, home-based patients with COPD receive specialist care from respiratory physicians, nurses, and general practitioners (GPs), but increasing complexity of therapeutic options and a GP/Nurse workforce crisis suggests merit in testing the role of home visits by a clinical pharmacist. We conducted a non-randomised intervention study with a contemporaneous comparator group, in Glasgow (Scotland). A clinical pharmacist (working closely with a consultant respiratory physician) visited patients with COPD living at home, assessing respiratory and other co-morbid conditions, and medicines then, with patient approval, agreed treatment modifications with a consultant physician. Comparator group-patients were drawn from another hospital out-patient clinic. Main outcomes were exacerbations during 4-months of follow-up and respiratory hospitalisations (number and duration) after 1 year. In the intervention group, 86 patients received a median of three home visits; 87 received usual care (UC). At baseline, patients in the intervention group were similar to those in UC in terms of respiratory hospitalisations although slightly younger, more likely to receive specific maintenance antibiotics/Prednisolone and to have had exacerbations. Sixty-two (72.1%) of the intervention group received dose changes; 45 (52.3%) had medicines stopped/started and 21 (24.4%) received an expedited review at the specialist respiratory consultant clinic; 46 (53.5%) were referred to other healthcare services. Over one-third were referred for bone scans and 11% received additional investigations. At follow-up, 54 (63.5%) of intervention group participants had an exacerbation compared with 75 (86.2%) in the UC group (p = 0.001); fewer had respiratory hospitalisations (39 (45.3%) vs. 66 (76.7%); p &lt; 0.001). Hospitalisations were shorter in the intervention group. Pharmacist-consultant care for community dwelling patients with COPD, changed clinical management and improved outcomes. A randomised controlled trial would establish causality

Residual effect of community antimicrobial exposure on risk of hospital onset healthcare associated Clostridioides difficile infection:a case-control study using national linked data

Background: Associations between antimicrobial exposure in the community and community-associated Clostridioides difficile infection (CA-CDI) are well documented but associations with healthcare-associated CDI (HA-CDI) are less clear. This study estimates the association between antimicrobial prescribing in the community and HA-CDI. Methods: A matched case–control study was conducted by linking three national patient level datasets covering CDI cases, community prescriptions and hospitalizations. All validated cases of HA-CDI (August 2010 to July 2013) were extracted and up to three hospital-based controls were matched to each case on the basis of gender, age, hospital and date of admission. Conditional logistic regression was applied to estimate the association between antimicrobial prescribing in the community and HA-CDI. A sensitivity analysis was conducted to consider the impact of unmeasured hospital antimicrobial prescribing. Results: Nine-hundred and thirty unique cases of HA-CDI with onset in hospital and no hospital discharge in the 12 weeks prior to index admission were linked with 1810 matched controls. Individuals with prior prescription of any antimicrobial in the community had an odds ratio (OR) = 1.41 (95% confidence interval (CI) 1.13–1.75) for HA-CDI compared with those without. Individuals exposed to high-risk antimicrobials (cephalosporins, clindamycin, co-amoxiclav or fluoroquinolones) had an OR = 1.86 (95% CI: 1.33–2.59). After accounting for the likely impact of unmeasured hospital prescribing, the community exposure, particulary to high-risk antimicrobials, was still associated with elevated HA-CDI risk. Conclusions: Community antimicrobial exposure is an independent risk factor for HA-CDI and should be considered as part of the risk assessment of patients developing diarrhoea in hospital