4,301 research outputs found

    Primary accumulation in the Soviet transition

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    The Soviet background to the idea of primary socialist accumulation is presented. The mobilisation of labour power and of products into public sector investment from outside are shown to have been the two original forms of the concept. In Soviet primary accumulation the mobilisation of labour power was apparently more decisive than the mobilisation of products. The primary accumulation process had both intended and unintended results. Intended results included bringing most of the economy into the public sector, and industrialisation of the economy as a whole. Unintended results included substantial economic losses, and the proliferation of coercive institutions damaging to attainment of the ultimate goal - the building of a communist society

    Normal left ventricular function does not protect against propafenone-induced incessant ventricular tachycardia

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    Propafenone is a class Ic anti-arrhythmic agent with mild B-blocking properties which has recently become available in South Africa. We have used the drug in 3 patients with sustained m.onomorphic ventricular tachycardia not due to ischaemic heart disease. All had norm.al left ventricular function; 1 had Wegener's granulom.atosis and 2 had arrhythmogenic right ventricular dysplasia. In the latter 2, propafenone provoked incessant monomorphic ventricular tachycardia which persisted for m.ore than 24 hours despite repeated efforts at term.ination. The morphology was similar to the patients' spontaneous ventricular tachycardia, but the rate was slower and the QRS complexes broader, consistent with propafenone's marked ability to slow intraventricular conduction. It is postulated that incessant tachycardia results from. perpetuation of re-entry due to marked conduction slowing produced by the drug. Previous reports have suggested that this is most likely to occur in patients with poor left ventricular function, but our experience indicates that those with normal left ventricular function are also at risk, particularly if the substrate for reentry is present. Propafenone, like all other powerful antiarrhythmic agents, may provoke life-threatening arrhythmias and should be used with great caution after due consideration of the indications, even in patients with norm.al left ventricular function

    Hierarchical porosity design enables highly recyclable and efficient Au/TiO2 composite fibers for photodegradation of organic pollutants

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    Titanium dioxide (TiO2) nanomaterials are ideal for photocatalytic degradation of organic pollutants but remain infeasible for industrial and municipal wastewater treatment because they cannot simultaneously satisfy two essential criteria for practical application, i.e., high performance and good recyclability. Here, we design and create hierarchically porous TiO2 fibers by dual-polymer templating sol–gel electrospinning combined with precise control over crystallization. The produced fibers own unique interconnected macropores throughout the fiber body that enable significantly enhanced light absorption and unlimited mass transport, making them ideal hosts for anchoring plasmonic nanoparticles (NPs). The Au NP-coupled TiO2 fibers have photocatalytic efficiencies up to 6.6 times higher than plain TiO2 fibers, showing comparable ability as commercial P25 nanopowder in photodegrading methyl blue (MB) and achieving complete decomposition of methyl orange (MO) in 90 min while P25 degrades only 66% MO. Unlike P25 or anatase TiO2 nanopowders that non-reversibly disperse/aggregate in water, our composite fibers can be recollected through natural sedimentation, and their superior performance remains for at least six cycles. This work offers a practical and feasible design for high-performance recyclable photocatalysts for industrial-scale water treatment

    Surgical cure of the Wolff-Parkinson-White syndrome a comparison of two techniques

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    Curative arrhythmia surgery for patients with symptomatic Wolff-Parkinson-White syndrome (WPW) was first performed in South Africa in November 1987. Pre-operatively all patients were symptomatic despite medical therapy, and 32% were assessed as being at risk for sudden death. The first 9 patients (November 1987 to December 1989) underwent either epicardial or localised endocardial surgical dissections, and a cure was obtained in 66%. Aberrant atrioventricular conduction recurred in 2 patients, 30 atrioventricular heart block occurred in 2 patients, and there was 1 postoperative death in a patient who had undergone simultaneous coronary artery bypass grafting. In contrast, a standardised endocardial technique was used in the subsequent 10 patients. Surgical cure was obtained in all 10 patients (P < 0,01). However, 1 patient required reoperation 24 hours after the first procedure because of early postoperative recurrence due to initial incorrect pathway localisation. This was successful. There were no deaths, and no patient developed atrioventricular heart block. In view of the excellent surgical results, arrhythmia surgery should be considered in select WPW patients who either have refractory symptoms or are at risk for sudden death. Furthermore, this reliable surgical technique provides an essential back-up should alternative interventionalprocedures such as percutaneous radiofrequency ablation fail

    Large scale grain mantle disruption in the Galactic Center

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    We present observations of C2H5OH toward molecular clouds in Sgr A, Sgr B2 and associated with thermal and non-thermal features in the Galactic center. C2H5OH emission in Sgr A and Sgr B2 is widespread, but not uniform. C2H5OH emission is much weaker or it is not detected in some molecular clouds in both complexes, in particular those with radial velocities between 70 and 120 km/s. While most of the clouds associated with the thermal features do not show C2H5OH emission, that associated with the Non-Thermal Radio Arc shows emission. The fractional abundance of C2H5OH in most of the clouds with radial velocities between 0 and 70 km/s in Sgr A and Sgr B2 is relatively high, of few 1e-8. The C2H5OH abundance decreases by more than one order of magnitude (aprox. 1e-9) in the clouds associated with the thermal features. The large abundance of C2H5OH in the gas-phase indicates that C2H5OH has formed in grains and released to gas-phase by shocks in the last aprox. 1e5 years.Comment: In press in Astrophysical Journal Letters 7 pages, 1 table, 1 figur

    Monitoring and evaluating business mentoring: towards a research and evaluation toolkit to measure impact

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    This paper presents a Research and Evaluation Toolkit (RET) which has applicability to mentoring programmes in all sectors and organizational contexts. The RET offers a practical guide for human resource development practitioners engaged in evaluation of learning and development programmes and more specifically, mentoring. The RET was a key outcome of a global 2.5-year impact evaluation project with Youth Business International and Middlesex University Business School, evaluating the impact of volunteer business mentoring on under-served young entrepreneurs and their business ventures. This paper brings to the forefront the importance of integrating a measurement and evaluation strategy from the initial mentoring programme design phase and ongoing management. Despite the growing number of survey reports and studies that highlight the importance of this aspect of mentoring programme design and management, measurement and evaluation continues to be one of the most challenging areas. As such, this paper contributes to our understanding concerning the role and effectiveness of ongoing monitoring and evaluation in relation to demonstrating the impact of human resource development interventions and provides a practical approach for practitioners to develop and enhance their evaluation strategy and methods. Key words: research and evaluation, business mentoring, impac

    Surgery for the Wolff-Parkinson-White syndrome - the Groote Schuur Hospital experience

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    Surgical division of accessory atrioventricular (AV) connections has been performetl on 9 patients with the WolffParkinson- White (WPW) syndrome at Groote Schuur Hospital. All patients had symptomatic paroxysmal tachycardia. The indication for surgery in 5 patients was poor control on antiarrhythmic drugs. Surgery was performed on a 15-year-old boy to prevent lifelong dependence on drugs, although his atrial fibrillation (ventricular rate> 300/min) was controllable with sotalol 1 280 mg daily. The remaining 3 patients required cilrdiac surgery for other indications and therefore their accessory pathways (APs) were divided concurrently. The AP was localised by pre-operative endocardial mapping and intra-operative epicardial mapping. There were 4 posteroseptal, 3 left free-wall and 2 right free-wall pathways. An endocardial approach was used to divide the pathways. All 5 free-wall APs were successfully divided without complications or recurrence. However, 1 patient with paroxysmal atrial fibrillation and severe unstable angina·due to coronary artery disease died unexpectedly 10 days after 4-vessel coronary bypass grafting and division of a posteroseptal AP. Postoperative complications occurred in a further 2 patients with posteroseptal APs. One patient developed complete heart block and is now asymptomatic with a DDD pacemaker, while the other had recurrence of retrograde bypass conduction postoperatively, but is now successfully controlled on sotalol. Therefore 7 of the 8 survivors are free of recurrence of tachycardia on no anti-arrhythmic drugs after a mean follow-up of 14,3 months. New insights into the surgical technique, particularly for division of posteroseptal pathways, can be expected to improve the outlook
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