School improvement through government agencies: loose or tight coupling?

In seeking to improve student outcomes, governments may choose to exercise direct control over schools, as in many centralised systems, or to provide frameworks for intermediate bodies to engage in improvement activities. One such body is the National College for School Leadership (NCSL), now the National College for Teaching and Leadership (NCTL) in England. The Department of Education of the South African province of Gauteng (GDE) has also chosen to implement its school improvement programmes partly through two specialist units, the Sci-Bono Discovery Centre, which focuses on maths, science and technology (MST), and the Matthew Goniwe School of Leadership and Governance (MGSLG), which specialises in school leadership, management, governance and teacher development. The purpose of this article is to report on an evaluation of the work of these two bodies, commissioned by the GDE as part of its 20th anniversary commemorations, through an analysis of relevant documents and interviews with 11 key actors in the operation of these specialist bodies. The article adopts loose coupling as its theoretical framework

Worldwide trends in quantity and quality of published articles in the field of infectious diseases

BACKGROUND: Trying to confront with the widespread burden of infectious diseases, the society worldwide invests considerably on research. We evaluated the contribution of different world regions in research production in Infectious Diseases. METHODS: Using the online Pubmed database we retrieved articles from 38 journals included in the "Infectious Diseases" category of the "Journal Citation Reports" database of the Institute for Scientific Information for the period 1995–2002. The world was divided into 9 regions based on geographic, economic and scientific criteria. Using an elaborate retrieval system we obtained data on published articles from different world regions. In our evaluation we introduced an estimate of both quantity and quality of research produced from each world region per year using: (1) the total number of publications, (2) the mean impact factor of publications, and (3) the product of the above two parameters. RESULTS: Data on the country of origin of the research was available for 45,232 out of 45,922 retrieved articles (98.5 %). USA and Western Europe are by far the most productive regions concerning publications of research articles. However, the rate of increase in the production of articles was higher in Eastern Europe, Africa, Latin America and the Caribbean, and Asia during the study period. The mean impact factor is highest for articles originating in the USA (3.42), while it was 2.82 for Western Europe and 2.73 for the rest of the world (7 regions combined). CONCLUSION: USA and Western Europe make up a striking 80% of the world's research production in Infectious Diseases in terms of both quantity and quality. However, all world regions achieved a gradual increase in the production of Infectious Diseases articles, with the regions ranking lower at present displaying the highest rate of increase

Elevated temperature material properties of stainless steel reinforcing bar

Corrosion of carbon steel reinforcing bar can lead to deterioration of concrete structures, especially in regions where road salt is heavily used or in areas close to sea water. Although stainless steel reinforcing bar costs more than carbon steel, its selective use for high risk elements is cost-effective when the whole life costs of the structure are taken into account. Considerations for specifying stainless steel reinforcing bars and a review of applications are presented herein. Attention is then given to the elevated temperature properties of stainless steel reinforcing bars, which are needed for structural fire design, but have been unexplored to date. A programme of isothermal and anisothermal tensile tests on four types of stainless steel reinforcing bar is described: 1.4307 (304L), 1.4311 (304LN), 1.4162 (LDX 2101®) and 1.4362 (2304). Bars of diameter 12 mm and 16 mm were studied, plain round and ribbed. Reduction factors were calculated for the key strength, stiffness and ductility properties and compared to equivalent factors for stainless steel plate and strip, as well as those for carbon steel reinforcement. The test results demonstrate that the reduction factors for 0.2% proof strength, strength at 2% strain and ultimate strength derived for stainless steel plate and strip can also be applied to stainless steel reinforcing bar. Revised reduction factors for ultimate strain and fracture strain at elevated temperatures have been proposed. The ability of two-stage Ramberg-Osgood expressions to capture accurately the stress-strain response of stainless steel reinforcement at both room temperature and elevated temperatures is also demonstrated

Survival in amoeba: a major selection pressure on the presence of bacterial copper and zinc resistance determinants?: identification of a "copper pathogenicity island"

The presence of metal resistance determinants in bacteria usually is attributed to geological or anthropogenic metal contamination in different environments or associated with the use of antimicrobial metals in human healthcare or in agriculture. While this is certainly true, we hypothesize that protozoan predation and macrophage killing are also responsible for selection of copper/zinc resistance genes in bacteria. In this review, we outline evidence supporting this hypothesis, as well as highlight the correlation between metal resistance and pathogenicity in bacteria. In addition, we introduce and characterize the "copper pathogenicity island" identified in Escherichia coli and Salmonella strains isolated from copper- and zinc-fed Danish pigs

Robustness of beam-to-column end-plate moment connections with stainless steel bolts subjected to high rates of loading

This paper presents an experimental investigation into end-plate beam column connections for buildings. The work demonstrates that a fourfold increase in the energy absorbed to failure can be achieved by replacing carbon steel bolts with their stainless steel counterparts. Experimental tests were carried out under load control, and these provided the opportunity to observe the time required for connection fracture. Under quasi-static loading, connections tested with stainless steel bolts showed clearly visible signs of distress prior to failure, whereas the carbon-steel-bolted equivalents provided no warning of failure prior to brittle fracture. Experimental tests were carried out on bolts, and these showed strain rate–induced strength enhancements. End-plate connections were also tested under high strain rates. Loading rate was not observed to significantly affect the performance of stainless steel–bolted connections. However, carbon-steel–bolted connections were observed to weaken under high-strain rates; therefore, dynamically increased material properties did not always translate into increase connection strength. The design strengths predicted using Eurocode 3 were found to be in good agreement with the experimentally observed values under quasi-static loading for both bolt types. Under high-strain-rate conditions, the Eurocode 3 method was also found to provide a good prediction for stainless steel-bolted connections but was found to over predict for carbon-steel connections. The simple modification of replacing carbon-steel bolts with their stainless steel equivalents is shown to be an effective way of improving the performance of industry standard connections. This modification is of relevance to the design of buildings and other structures in which the ductility is of high importance; for example, in structures which may need to resist transient loads from blast or impact