589 research outputs found
Gyrotron experiments employing a field emission array cathode
The design and operation of a field emission array (FEA) cathode and the subsequent demonstration of the first FEA gyrotron are presented. Up to 10 mA from 30 000 tips was achieved reproducibly from each of ten chips in a gyrotron environment, namely, a vacuum 1 x 10(-8) mbar, -50 kV potential with multiple chip operation, The design parameters of the FEA gun were similar to those of a magnetron injection gun with an achievable electron beam current of 50-100 mA and measured power 720 W cw. Coherent microwave radiation was detected in both TE(02) at 30.1 GHz and TE(03) at 43.6 GHz, with a starting current of 1 mA
Improving chlamydia knowledge should lead to increased chlamydia testing among Australian general practitioners: a cross-sectional study of chlamydia testing uptake in general practice
Female general practitioners (GPs) have higher chlamydia testing rates than male GPs, yet it is unclear whether this is due to lack of knowledge among male GPs or because female GPs consult and test more female patients
Should beta-blocker therapy be reduced or withdrawn after an episode of decompensated heart failure? Results from COMET.
BACKGROUND:
It is unclear whether beta-blocker therapy should be reduced or withdrawn in patients who develop acute decompensated heart failure (HF). We studied the relationship between changes in beta-blocker dose and outcome in patients surviving a HF hospitalisation in COMET.
METHODS:
Patients hospitalised for HF were subdivided on the basis of the beta-blocker dose administered at the visit following hospitalisation, compared to that administered before.
RESULTS:
In COMET, 752/3029 patients (25%, 361 carvedilol and 391 metoprolol) had a non-fatal HF hospitalisation while on study treatment. Of these, 61 patients (8%) had beta-blocker treatment withdrawn, 162 (22%) had a dose reduction and 529 (70%) were maintained on the same dose. One-and two-year cumulative mortality rates were 28.7% and 44.6% for patients withdrawn from study medication, 37.4% and 51.4% for those with a reduced dosage (n.s.) and 19.1% and 32.5% for those maintained on the same dose (HR,1.59; 95%CI, 1.28-1.98; p<0.001, compared to the others). The result remained significant in a multivariable model: (HR, 1.30; 95%CI, 1.02-1.66; p=0.0318). No interaction with the beneficial effects of carvedilol, compared to metoprolol, on outcome was observed (p=0.8436).
CONCLUSIONS:
HF hospitalisations are associated with a high subsequent mortality. The risk of death is higher in patients who discontinue beta-blocker therapy or have their dose reduced. The increase in mortality is only partially explained by the worse prognostic profile of these patients
Literary remains:Muriel Spark, auto|biography, and the archive
This essay explores Muriel Spark’s archival practice as a form of auto|biography, charting the relationship between Spark’s archives and her published work, and inquiring into the place of archives in literary and cultural studies: What are we doing in writers’ archives? And what is the archive doing here
Executive functions in adults with developmental dyslexia
Background: Executive functioning (EF) deficits are well recognized in developmental dyslexia, yet the majority of studies have concerned children rather than adults, ignored the subjective experience of the individual with dyslexia (with regard to their own EFs), and have not followed current theoretical perspectives on EFs.
Aims and Methods: The current study addressed these shortfalls by administering a self-report measure of EF (BRIEF-A; Roth, Isquith & Gioia, 2005) and experimental tasks to IQ-matched groups of adults with and without dyslexia. The laboratory-based tasks tested the three factors constituting the framework of EF proposed by Miyake et al. (2000).
Results: In comparison to the group without dyslexia, the participants with dyslexia self-reported more frequent EF problems in day-to-day life, with these difficulties centering on metacognitive processes (working memory, planning, task monitoring, and organization) rather than on the regulation of emotion and behaviour. The participants with dyslexia showed significant deficits in EF (inhibition, set shifting, and working memory).
Conclusions and Implications: The findings indicated that dyslexia-related problems have an impact on the daily experience of adults with the condition. Further, EF difficulties are present in adulthood across a range of laboratory-based measures, and, given the nature of the experimental tasks presented, extend beyond difficulties related solely to phonological processing
The pleasures and perils of inheritance
Facing death, reflecting on one’s legacies (material and ethical, personal and political) and the legal and interpersonal attempts to resolve or prevent inheritance conflicts, all bring to the fore constructions of memory and identity, intergenerational relations, and the complexities of doing and undoing family and kinship. Consequently, drawing attention to inheritance, keeping sight of it, and bringing it into play is a useful piece of the puzzle of ageing across a range of disciplines and this article provides an overview of some of the key themes in this emerging field
An observational study of patient characteristics associated with the mode of admission to acute stroke services in North East, England
Objective
Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services.
Study design and setting
A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases.
Results
Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis.
Conclusion
Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations
Reducing quality control errors by guiding behavior
It is estimated that human error in the quality control checking of product labels on consumer packaging costs the UK retail industry £50m per annum. Our research program aimed to understand the behavior of individuals when performing label checks on fresh produce in order to inform the development of a software application designed to support quality control. On a simulated label checking task, eye-tracking data showed that individuals used different checking methods. A more systematic method led to higher accuracy. Two computer-assisted approaches, varying in the level of computer support provided, were then designed to push checkers towards systematic checking. Greater improvements in accuracy were found under the computer-assisted approaches than under a control condition. A three-month onsite trial of a software application designed on the basis of these research findings led to a 100% decrease in quality control errors
Sorption-Desorption Behavior of Atrazine on Soils Subjected to Different Organic Long-Term Amendments
Sorption of atrazine on soils subjected to three different organic amendments was measured using a batch equilibrium technique. A higher K(F) value (2.20 kg(-1)(mg L(-1))(-)N) was obtained for soil fertilized with compost, which had a higher organic matter (OM) content. A correlation between the K(Foc) values and the percentage of aromatic carbon in OM was observed. The highest K(Foc) value was obtained for the soil with the highest aromatic content. Higher aromatic content results in higher hydrophobicity of OM, and hydrophobic interactions play a key role in binding of atrazine, On the other hand, the soil amended with farmyard manure had a higher content of carboxylic units, which could be responsible for hydrogen bonding between atrazine and OR Dominance of hydrogen bonds compared to hydrophobic interactions can be responsible for the lower desorption capacity observed with the farmyard manure soil, The stronger hydrogen bonding can reduce the leaching of atrazine into drinking water resources and runoff to rivers and other surface waters
Optimal approaches to the quality control checking of product labels
Quality control checkers at fresh produce packaging facilities occasionally fail to detect incorrect information presented on labels. Despite being infrequent, such errors have significant financial and environmental repercussions. To understand why label-checking errors occur, observations and interviews were undertaken at a large packaging facility and followed up with a laboratory-based label-checking task. The observations highlighted the dynamic, complex environment in which label-checking took place, whilst the interviews revealed that operatives had not received formal training in label-checking. On the laboratory-based task, overall error detection accuracy was high but considerable individual differences were found between professional label-checkers. Response times were shorter when participants failed to detect label errors, suggesting incomplete checking or ineffective checking strategies. Furthermore, eye movement recordings indicated that checkers who adopted a systematic approach to checking were more successful in detecting errors. The extent to which a label checker adopted a systematic approach was not found to correlate with the number of years of experience that they had accrued in label-checking. To minimize the chances of label errors going undetected, explicit instruction and training, personnel selection and/or the use of software to guide performance towards a more systematic approach is recommended
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