A Wideband, Four-Element, All-Digital Beamforming System for Dense Aperture Arrays in Radio Astronomy

Densely-packed, all-digital aperture arrays form a key area of technology development required for the Square Kilometre Array (SKA) radio telescope. The design of real-time signal processing systems for digital aperture arrays is currently a central challenge in pathfinder projects worldwide. We describe interim results of such work; an heirarchical, frequency-domain beamforming architecture for synthesising a sky beam from the wideband antenna feeds of digital aperture arrays.Comment: 4 pages, 6 figure

Glycosylated haemoglobin (HbA1c) and cortisol levels on admission to intensive care as predictors of outcome

Objective: To evaluate the predictive value of glycosylated haemoglobin and cortisol on admission, in critical care patients. Design: Prospective, observational, single centre study. Setting: 14 bedded Intensive care unit of a tertiary-level university hospital. Patients: 124 consecutive emergency medical and surgical patients. Methods: Data collected on admission included patient demographics, medical history, medication, diagnosis, type of nutrition, TISS28 score, serum blood glucose, Glycosylated haemoglobin (HbA1c), cortisol, mean arterial blood pressure, and the use of inotropes in the first 24hrs. Daily baseline tests included complete blood count, urea and electrolytes, creatinine, twice weekly liver function tests. The primary outcome measure was intensive care unit mortality. Secondary outcome measures were ITU stay, days of ventilation, peak urea, peak creatinine, lowest platelet count, peak bilirubin, lowest Pa/FiO2, and the number of transfusions. Measurements and results: 124 patients (mean age 56.2 years SD 23.2) were included. Regression analysis was used to identify any potential predictors of outcome: HbA1c levels on admission were not found to be significantly associated with mortality (p=0.51), or any other secondary endpoints listed above. However, subgroup analysis revealed a predictive role of HbA1c with regards to length of ITU stay (p= 0.01) and number of days of ventilation (p=0.007) in those patients with a history of diabetes. Glucose level on admission emerged as an independent marker of mortality (p=0.009). Conclusions: This study suggests that HbA1c may not be a predictor of outcome in the general ITU population but may be of predictive value in diabetic ITU patients. On the other hand, blood glucose levels on admission emerged as a predictor of mortality, whilst no association was found between HbA1c and cortisol levels on admission.peer-reviewe

Identification of targets for quality improvement in antimicrobial prescribing : the web-based ESAC Point Prevalence Survey 2009

Objectives: Since electronic prescribing is limited to few hospitals, point prevalence surveys, such as the standardized European Surveillance of Antimicrobial Consumption point prevalence survey (ESAC PPS), are an alternative tool for monitoring prescribing and helping to identify performance indicators and prescribing trends. The main objective of this study was to identify and assess targets for quality improvement. Methods: Each hospital had to carry out the survey within 2 weeks. Each department had to be surveyed in 1 day. Data collected, for all inpatients, included age and gender. For patients on systemic antimicrobial treatment, the antimicrobial/s, infection/prophylaxis site, reason in medical notes and guideline compliance were also collected. A central database using a web-based tool (WebPPS) developed in-house was used for data entry. Results: Combination of two or more antimicrobials accounted for 30% of use. Surgical prophylaxis was prolonged (>1 day) in 53% of cases. 'Intensive care' had higher proportions of treated patients (53% versus 29%), combination therapy (49% versus 31%), hospital-acquired infections (49% versus 31%) and parenteral administration (91% versus 61%). 'Reason in notes' was documented in 76%, and 'guideline compliance' occurred in 62% of patients. Conclusions: The ESAC PPS provided useful information on the quality of prescribing, which identified a number of targets for quality improvement. These could apply to specific departments or whole hospitals. Intensive care, which has different characteristics, should not be compared with general wards with respect to combination therapy, hospital-acquired infections or parenteral proportion. The study confirmed that the ESAC PPS methodology can be used on a large number of hospitals at regional, national, continental or global level.The ESAC project was supported by a grant from the European Centre for Disease Prevention and Control (ECDC; Grant Agreement 2007/001).peer-reviewe

From ‘other’ to involved: User involvement in research: An emerging paradigm

This article has been made available through the Brunel Open Access Publishing Fund. Copyright @ 2013 The Author(s). This is an Open Access article. Non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly attributed, cited, and is not altered, transformed, or built upon in any way, is permitted. The moral rights of the named author(s) have been asserted.This article explores the issue of ‘othering’ service users and the role that involving them, particularly in social policy and social work research may play in reducing this. It takes, as its starting point, the concept of ‘social exclusion’, which has developed in Europe and the marginal role that those who have been included in this construct have played in its development and the damaging effects this may have. The article explores service user involvement in research and is itself written from a service user perspective. It pays particular attention to the ideological, practical, theoretical, ethical and methodological issues that such user involvement may raise for research. It examines problems that both research and user involvement may give rise to and also considers developments internationally to involve service users/subjects of research, highlighting some of the possible implications and gains of engaging service user knowledge in research and the need for this to be evaluated

Development and characterization of a stable adhesive bond between a poly(dimethylsiloxane) catheter material and a bacterial biofilm resistant acrylate polymer coating

Catheter associated urinary tract infections (CA-UTIs) are the most common health related infections world wide, contributing significantly to patient morbidity and mortality and increased health care costs. To reduce the incidence of these infections, new materials that resist bacterial biofilm formation are needed. A composite catheter material, consisting of bulk PDMS coated with a novel bacterial biofilm resistant polyacrylate (EGDPEA–co-DEGMA) has been proposed. The coated material shows excellent bacterial resistance when compared to commercial catheter materials but delamination of the coatings under mechanical stress presents a challenge. In this work, the use of oxygen plasma treatment to improve the wettability and reactivity of the PDMS catheter material and improve adhesion with the EGDPEA–co-DEGMA coating has been investigated. Argon Cluster 3D-imaging Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) has been used to probe the buried adhesive interface between the EGDPEA–co-DEGMA coating and the treated PDMS. ToF-SIMS analysis was performed in both dry and frozen-hydrated states and results were compared to mechanical tests. From the ToF-SIMS data we have been able to observe the presence of PDMS, silicates, salt particles, cracks and water at the adhesive interface. In the dry catheters, low molecular weight PDMS oligomers at the interface were associated with poor adhesion. When hydrated, the hydrophilic silicates attracted water to the interface and led to easy delamination of the coating. The best adhesion results, under hydrated conditions, were obtained using a combination of 5 min O2 plasma treatment and silane primers. Cryo-ToF-SIMS analysis of the hydrated catheter material showed that the bond between the primed PDMS catheter and the EGDPEA–co-DEGMA coating was stable in the presence of water. The resulting catheter material was resisted Escherichia coli and Proteus mirabilis biofilm colonization by up to 95 % compared with uncoated PDMS after 10 days of continuous bacterial exposure and had the mechanical properties necessary for use as a urinary catheter

Pre‑operative pain sensitivity : a prediction of post‑operative outcome in the obstetric population

Context: Experimental assessments can determine pain threshold and tolerance, which mirror sensitivity to pain. This, in turn, influences the post‑operative experience. Aims: The study intended to evaluate whether the pre‑operative pressure and electrical pain tests can predict pain and opioid requirement following cesarean delivery. Settings and Design: Research was conducted on females scheduled for cesarean section at a tertiary care hospital of the state. Twenty women were enrolled, after obtaining written informed consent. Materials and Methods: Pain assessment was performed on the eve of cesarean sections using three devices: PainMatcher® determined electrical pain threshold while the algometers PainTest™ FPN100 (manual) and PainTest™ FPX 25 (digital) evaluated pressure pain threshold and tolerance. Post‑operative pain relief included intravenous morphine administered by patient‑controlled analgesia, diclofenac (100 mg, every 12 h, rectally, enforced) and paracetamol (1000 mg, every 4‑6 h, orally, on patient request). Pain scores were reported on numerical rating scales at specified time intervals. Statistical Analysis Used: Correlational and regression statistics were computed using IBM SPSS Statistics 21 software (IBM Corporation, USA). Results: A significant correlation was observed between morphine requirement and: (1) electrical pain threshold (r = –0.45, P = 0.025), (2) pressure pain threshold (r = –0.41 P = 0.036) and (3) pressure pain tolerance (r = –0.44, P = 0.026) measured by the digital algometer. The parsimonious regression model for morphine requirement consisted of electrical pain threshold (r2 = 0.20, P = 0.049). The dose of morphine consumed within 48 h of surgery decreases by 0.9 mg for every unit increment in electrical pain threshold. Conclusions: The predictive power of pain sensitivity assessments, particularly electrical pain threshold, may portend post‑cesarean outcomes, including opioid requirements.peer-reviewe

Beamforming techniques for large-n aperture arrays

Beamforming is central to the processing function of all phased arrays and becomes particularly challenging with a large number of antenna element (e.g. >100,000). The ability to beamform efficiently with reasonable power requirements is discussed in this paper. Whilst the most appropriate beamforming technology will change over time due to semiconductor and processing developments, we present a hierarchical structure which is technology agnostic and describe both Radio-Frequency (RF) and digital hierarchical beamforming approaches. We present implementations of both RF and digital beamforming systems on two antenna array demonstrators, namely the Electronic Multi Beam Radio Astronomy ConcEpt (EMBRACE) and the dual-polarisation all-digital array (2-PAD). This paper will compare and contrast both digital and analogue implementations without considering the deep system design of these arrays.peer-reviewe

The reliability of the McCabe score as a marker of co-morbidity in healthcare-associated infection point prevalence studies

This study aimed to ascertain the reliability of the McCabe score in a healthcare-associated infection point prevalence survey.   A 10 European Union Member States survey in 20 hospitals (n = 1912) indicated that there was a moderate level of agreement (κ = 0.57) with the score. The reliability of the application of the score could be increased by training data collectors, particularly with reference to the ultimately fatal criteria. This is important if the score is to be used to risk adjust data to drive infection prevention and control interventions