Medications and cataract. The Blue Mountains Eye Study

PURPOSE: Corticosteroids are known to cause cataracts, but the effects of other medications on the lens are unclear. The aim of this study was to investigate the relationships between cataracts and a range of medications, including allopurinol, aspirin, chloroquine, diuretics, phenothiazines, and simvastatin. DESIGN: Population-based cross-sectional study. PARTICIPANTS: 3654 individuals 49 to 97 years of age (response rate, 82%) from an urban community near Sydney, Australia, were included. TESTING: Lens photography. PRIMARY OUTCOME MEASURE: Lens photographs were graded for the presence and severity of cortical, nuclear, and posterior subcapsular cataract. RESULTS: After adjusting for numerous potential confounders in ordinal regression models, use of phenothiazines was associated with nuclear cataract (adjusted odds ratio [OR], 2.18; 95% confidence interval [CI], 1.01-4.74); long-term aspirin users (> or = 10 years) had higher prevalence of posterior subcapsular cataract than did nonusers and short-term users (test for trend, P = 0.02); and the antimalarial drug mepacrine was associated with posterior subcapsular cataract (adjusted OR, 3.56; 95% CI, 1.56-8.13). There was a suggestion that use of chloroquine-like drugs for more than 1 year (test for trend, P = 0.12) might also be associated with posterior subcapsular cataract. Antihypertensive medications, cholesterol-lowering drugs, and allopurinol were not associated with any type of cataract. Potassium-sparing diuretics were the only diuretic to show any evidence of an association with cataract (test for trend for posterior subcapsular cataract, P = 0.14). Amiodarone was associated with cortical cataract (age- and gender-adjusted OR, 3.84; 95% CI, 1.01-14.81), but there were too few users to do analyses adjusted for multiple confounders. CONCLUSIONS: Most drugs commonly used in the community do not appear to be associated with cataract. The findings of this study do not support the hypothesis that aspirin protects against cataract.     

Method to measure CVT transfer function

In this paper, the results of tests on a 275 and a 400 kV capacitor voltage transformer are presented. The objective has been to determine the transfer function of the CVTs in the Scottish Power extra-high-voltage (EHV) system, which in turn can be used to compensate for the errors at harmonic frequencies. As a primary requirement, the magnetic elements of the capacitor voltage transformers (CVTs) must be excited at nearly their nominal magnetic states. A test procedure is presented, which does not require CVT disassembling and/or modeling and ensures that the above essential requirement is satisfied. The effects of burden on the frequency response is also presented. It is confirmed that the size and nature of burden affect the CVT frequency characteristic.     

Concerning the maximum frequency limits of Gunn operators

The length of the transit region of a Gunn diode determines the natural frequency at which it operates in fundamental mode－the shorter the device, the higher the frequency of operation. The long-held view on Gunn diode design is that for a functioning device the minimum length of the transit region is about 1.5 μm, limiting the devices to fundamental mode operation at frequencies of roughly 60 GHz. The authors posit that this theoretical restriction is a consequence of limits of the hydrodynamic models by which it was determined. Study of these devices by more advanced Monte Carlo techniques, which simulate the ballistic transport and electron-phonon interactions that govern device behaviour, offers a new lower bound of 0.5 μm, which is already being approached by the experimental evidence shown in planar and vertical devices exhibiting Gunn operation at 0.6 μm and 0.7 μm. It is shown that the limits for Gunn domain operation are determined by the device length required for the transferred electron effect to occur(approximately 0.15 μm, which as demonstrated is largely field independent) and the fundamental size of the domain(approximately 0.3 μm). At this new length, operation in fundamental mode at much higher frequencies becomes possible－the Monte Carlo model used predicts power output at frequencies over 300 GHz.     

Synthesis and in vitro antimalarial activity of sulfone endoperoxides

A series of 4,8-dimethyl-4-phenylsulfonylmethyl-2,3-dioxabicyclo[3.3.1]+ ++nonanes, carrying a variety of substituents at position-8 (4) were prepared by a short and efficient method from R-(+)-limonene. Key reactions include thiol oxygen cooxidation, and alkylation and acylation of a sterically hindered tertiary alcohol compatible with the endoperoxy functionality. Some of compounds 4, which are structurally related to yingzhaosu A (2), were found to exhibit in vitro antimalarial activity comparable to that of artemisinin (1) and superior to that of arteflene (3).     

On-line identification of a steel mill

This paper describes measurements and on-line identification carried out on a tandem steel mill as part of a project to develop an improved computer control system for the mill. The paper does not dwell on theoretical points, but presents a view of how a difficult modelling problem can be handled in practice with rather simple means. It is hoped that the paper will be of value to those who are planning similar modelling experiments.     

Ethnic origin, belief, and personality information in interpersonal attraction.

To test the effects on interpersonal attraction of 3 categories of information, 78 English-speaking undergraduates made liking and social distance ratings about a derived target. The person rated was either English or French Canadian, pro- or anti-capital-punishment and the harsh treatment of criminals, and high or low on the Cognitive Structure and Order scales of the Personality Research Form. Results show that the judges were all anti-capital-punishment and low on the personality traits. Belief and belief-congruence were the primary determinants of attraction. The 3 categories of information interacted on 2 measures. French Canadians were rated more favorably than English-Canadians when similar to the judge in belief or personality but less favorably when similar in neither belief nor personality. (French summary) (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding the cortical specialization for horizontal disparity

Because the eyes are displaced horizontally, binocular vision is inherently anisotropic. Recent experimental work has uncovered evidence of this anisotropy in primary visual cortex (V1): neurons respond over a wider range of horizontal than vertical disparity, regardless of their orientation tuning. This probably reflects the horizontally elongated distribution of two-dimensional disparity experienced by the visual system, but it conflicts with all existing models of disparity selectivity, in which the relative response range to vertical and horizontal disparities is determined by the preferred orientation. Potentially, this discrepancy could require us to abandon the widely held view that processing in V1 neurons is initially linear. Here, we show that these new experimental data can be reconciled with an initial linear stage; we present two physiologically plausible ways of extending existing models to achieve this. First, we allow neurons to receive input from multiple binocular subunits with different position disparities (previous models have assumed all subunits have identical position and phase disparity). Then we incorporate a form of divisive normalization, which has successfully explained many response properties of V1 neurons but has not previously been incorporated into a model of disparity selectivity. We show that either of these mechanisms decouples disparity tuning from orientation tuning and discuss how the models could be tested experimentally. This represents the first explanation of how the cortical specialization for horizontal disparity may be achieved.     

Variable polarisation compensator using artificial dielectrics formillimetre and submillimetre waves

A variable polarisation compensator has been designed and demonstrated experimentally at 100 GHz. The device uses two silicon plates with interlocking artificial dielectric surfaces to produce a birefringence that varies with the separation distance. The experimental results indicate a maximum differential phase-shift of 74°, and show good agreement with computer simulations     

Surface properties of electrochemically oxidised viscose rayon based carbon fibres

A viscose rayon based activated carbon cloth (ACC) was subjected to electrochemical oxidation under a wide variety of current conditions to modify the surface properties. The changes in the surface properties were physically and chemically characterised. The cation exchange capacity of ACC increased with an increase in the extent of oxidation. The electrochemically oxidised ACC at 1.1 A for 6 h showed highest cation exchange capacity without any change in surface morphology. A loss of 49% BET surface area and a significant loss in microporosity were observed and attributed to blockage of pores through formation of carboxylic acidic groups and humic substances. However, the cation exchange capacity and oxygen content increased by about 365% and 121%, respectively. Increase in surface acidity shifted the point of zero charge from pH of 6.8 to 2.8 and the isoelectric point from pH of 3 to 1.15. The optimum constant current for electrochemical oxidation was found to be 1.1 A.     

Neural networks for monitoring of engine condition data

Neural networks are being tested to monitor aircraft engine condition data, in addition to current techniques and newer methods such as knowledge-based systems or case-based reasoning, in order to increase safety and assist in aircraft maintenance activity. It is possible that neural networks can help to measure subtle changes in a wide number of variables, and produce indications of adverse trends to serve as early warning signals. Unsupervised networks were trained on 300 records, each with 31 attributes, and independently validated on 1662 records (the recall set). Results are presented for self-organising maps and recirculation networks. The next phase is to incorporate diagnostic capability by adding a supervised learning element. Monitoring of sensor reliability and the provision of confidence limits are further extensions of these approaches.