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Introduction: Conventional chest CT is usually performed in the setting between 220-280 mAs. Increase use of CT in recent times has the potential to increase radiation burden to the general population. The purpose of this study was to evaluate the image quality in CT Chest with 50% mAs reduction. Methods: This prospective study was done in 101 patients with age above 18 years and BMI less than 25kg/m2 who were referred for CECT chest examination. A 16 slice multi detector CT scanner was used to acquire non contrast at 120 kVp and 140 mAs, a modified protocol with 50% reduction in mAsand contrast enhanced scan at standard protocol of 120 kVp and 280 mAs. The images of plain and contrast enhanced scans were evaluated by two expert radiologists and given the image quality score in 5 point scale (1-worst, 2-suboptimal, 3-adequate, 4-good, 5-excellent) to each. Image noise was measured in images of each patient. Patient weight, height and BMI were recorded and correlated with image quality score. Statistical analysis was done with relevant test. Results: The overall image quality with standard protocol was significantly better (p<0.05) than modified protocol. The modified protocol had acceptable image quality score for patients with weight< 60 kg, BMI<25kg/m2. The CTDIvol was 11.15 with reduced mAs and 22.15 with standard mAs resulting in significant reduction in radiation dose of about 49%. Conclusion: Image quality of modified protocol with 50% mAs reduction i.e.140 mAs is acceptable for average built patients and not patients with large anthropometric parameters. [ABSTRACT FROM AUTHOR]

Exposure to suspended particulate matter and carbon monoxide from indoor kitchen lair can have significant effects on respiratory health as demonstrated by statistical modelling. Chronic respiratory illnesses and respiratory symptoms are modelled using the techniques of principal component analysis and binary logistic regression. Estimated models are generated from a cross-sectional household survey data conducted in Nepal with 168 respondents who cook for daily meals. The models show that individuals exposed to high levels of indoor air pollution particularly associated with unprocessed solid biomass fuels along with aging, tobacco smoking and living in poorly, constructed houses mainly with mud are vulnerable to respiratory disorders. [ABSTRACT FROM AUTHOR]

Arbovirus surveillance was conducted during an epizootic of western equine encephalitis (WEE) during 1987 and during a nonepizootic year, 1991, in the same area in northern Colorado. Mosquitoes were collected in Larimer County, CO, during weeks 33-37 (10 August to 7 September) in 1987 and during weeks 26-35 (24 June to 26 August) in 1991. In total, 13,099 mosquitoes in 694 pools collected during 1987 and 8,672 mosquitoes in 242 pools collected during 1991 were tested for virus. WEE virus was isolated in both years from Culex tarsalis Coquillett and from Cx. pipiens L. in 1987. Infection rates and population levels of Cx. tarsalis were not significantly different in the 2 yr during weeks 33, 34, and 35 (12-26 August). St. Louis encephalitis virus was isolated in 1987 from Cx. tarsalis. Other viruses isolated included Hart Park, Turlock, and Jerry Slough, a variety of Jamestown Canyon virus.

Tharus--a population of Terai (a region with a severe malarial morbidity in the past)--can be subdivided into three main groups: Western, Central and Southern Tharus. They have usually been considered a Mongoloid population and this has been further substantiated by mtDNA findings on Central Tharus. Studies on the distribution of malaria-related genes have shown an extremely high frequency (0.8) of the alpha-thal gene among Western and Central Tharus. This frequency, however, unexpectedly turned out to be only 0.04 in a sample of Eastern Tharus. This raised doubts on the common notion that Tharus are a single anthropological entity. In the present investigation mtDNA markers were studied in the same sample of Eastern Tharus previously examined for the alpha-thal gene. The findings were: 1. the same three features which confirmed the classification of Central Tharus as Mongoloids (i.e., the common occurrence of HpaI-1/HincII-1 and HaeII-5 morphs, and the lack of BamHI polymorphism) were also present in this sample. Since the only neighbouring population accessible to Tharus, until recently, has been Hindu (Caucasoids), this result strongly supports the notion that Tharus are indeed a single anthropological entity; 2. two statistically significant differences between Eastern and Central Tharus--namely, a much higher HaeII morph 5 frequency among Central Tharus, and the absence in the same group of the mutation at 15.487 bp (very common among Eastern Tharus)--together with the results on alpha-tal gene, suggested that Tharu subgroups underwent an effective reproductive isolation.