New stand magnifiers do not meet rated levels of performance

A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'_v) rather than equivalent dioptric power (F_m) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.     

Adverse learning strategy: the Adelaide Diagnostic Learning Inventory and its subscale replicability in a medical student population

The Adelaide Diagnostic Learning Inventory (ADLIMS) is a measure of learning styles and learning pathologies that was designed to investigate the impact of traditional approaches to learning versus problem-based learning and to identify students whose approach to learning tasks predicted poor academic performance. In this study, some important psychometric properties of the ADLIMS were examined, including its factor structure. In this study, factor replicability across samples was argued to provide a more robust and psychologically meaningful factor solution than that which can be obtained using traditional mathematical criteria. The results of the factor analysis did not confirm the presence of the four factor solution earlier reported for the ADLIMS, but did identify three clear factors that had very high replicability. An inspection of the items comprising these three factors showed that factor 1 tapped subjective distress related to poor study habits, lack of motivation to study, and distraction from social activities. Factor 2 tapped distress arising from high achievement expectations that were hampered by superficial or disorganized study habits that did not enable the student to grasp the relationships between concepts and ideas. Factor 3 tapped positive feelings and a sense of satisfaction associated with a problem-based approach to the learning of new study material. Although the internal reliability of the ADLIMS subscales met the requirements of a measure to be used in general research such as in the investigation of correlates among groups of medical students, they did not meet the higher requirements of a measure to be used to identify or predict individuals with pathological learning styles.     

Public-private partnership in water supply and sanitation in Sub-Saharan Africa

Purely public water supply systems are characterized by highcosts, insufficient supplies and chronic deficits that are coveredby central government transfers. The private water supply programmein Abidjan has not met its coverage targets either, but thesystem has remained financially solvent and fostered a rapidgrowth in capacity through the informal sector. The materialreviewed here and the experience of developing country watersystems in general support several conclusions. (1) Water vendingis common in developing countries, which suggests that chargingfor water is not culturally unacceptable. Demand for wastewaterservices is low, but surcharges could be imposed on water usageto cover some sanitation costs. (2) Incentives are criticalto sound management of water supply and sanitation services.They are typically part of the structure of private firms, butare rare in publicly run systems. (3) The private sector's rolein the provision of water supply and sanitation can be extensive.Regulation of private activity and quality control by publicauthorities is essential to maintain competition and ensureproper and fair operation. (4) Public efforts to supply watercan be supplemented by a government-regulated, parallel systemto increase the amount of water available. Normally these systemsinvolve trucked water, but private sales outlets with pipe infrastructureshould be encouraged where feasible. (5) Even where the publicsector decides to control and operate the water supply and sanitationsystem, some partnership with the private sector is possiblethrough contracting out specific tasks such as billing, metering,maintenance of various components or tracking water losses.Finally, the supply of water is an ideal activity for a public-privatepartnership. Both sectors have comparative advantages that arebest applied in conjunction with the other.     

A prospective study of colposcopy in women with mild dyskaryosis or koilocytosis

Summary. Colposcopy was performed in 91 women who had cervical cytology suggesting mild dyskaryosis or showing koilocytosis, all previous cytology having been normal. The final histological diagnosis was C1N III in 22%, CINII in 18%, CINI in 31%, koilocytosis alone in 14% and no abnormality in 15%. These results indicate that even with mild cytological atypia, a high proportion of patients will have more advanced disease when colposcopy-directed punch biopsy is performed.