Additional Explanatory Factors Research Articles

Television station ownership characteristics and local news and public affairs programming: an expanded analysis of FCC data

This paper examines the relationship between television station ownership characteristics and local news and public affairs programming through an expanded analysis of data from the Federal Communication's Commission (FCC's) recent study of Big Four broadcast network affiliates. The results indicate that the FCC's conclusion that network‐owned and operated stations provide more local news and public affairs programming than other affiliates, and that stations with newspaper holdings provide more local news and public affairs programming than stations without newspaper holdings holds up only when these two program types are analyzed in combination. When these two program types are analyzed independently, and when additional explanatory factors are taken into consideration, these ownership characteristics are positively related to news programming, but not to public affairs programming.

Rethinking cystic fibrosis pathology: the critical role of abnormal reduced glutathione (GSH) transport caused by CFTR mutation

Though the cause of cystic fibrosis (CF) pathology is understood to be the mutation of the CFTR protein, it has been difficult to trace the exact mechanisms by which the pathology arises and progresses from the mutation. Recent research findings have noted that the CFTR channel is not only permeant to chloride anions, but other, larger organic anions, including reduced glutathione (GSH). This explains the longstanding finding of extracellular GSH deficit and dramatically reduced extracellular GSH:GSSG (glutathione disulfide) ratio found to be chronic and progressive in CF patients. Given the vital role of GSH as an antioxidant, a mucolytic, and a regulator of inflammation, immune response, and cell viability via its redox status in the human body, it is reasonable to hypothesize that this condition plays some role in the pathogenesis of CF. This hypothesis is advanced by comparing the literature on pathological phenomena associated with GSH deficiency to the literature documenting CF pathology, with striking similarities noted. Several puzzling hallmarks of CF pathology, including reduced exhaled NO, exaggerated inflammation with decreased immunocompetence, increased mucus viscoelasticity, and lack of appropriate apoptosis by infected epithelial cells, are better understood when abnormal GSH transport from epithelia (those without anion channels redundant to the CFTR at the apical surface) is added as an additional explanatory factor. Such epithelia should have normal levels of total glutathione (though perhaps with diminished GSH:GSSG ratio in the cytosol), but impaired GSH transport due to CFTR mutation should lead to progressive extracellular deficit of both total glutathione and GSH, and, hypothetically, GSH:GSSG ratio alteration or even total glutathione deficit in cells with redundant anion channels, such as leukocytes, lymphocytes, erythrocytes, and hepatocytes. Therapeutic implications, including alternative methods of GSH augmentation, are discussed.

Housing Turks and Moroccans in Brussels and Amsterdam: The Difference between Private and Public Markets

In this paper, the settlement patterns of Turks and Moroccans in Brussels will be compared with the patterns of the same groups in Amsterdam. It will be argued that housing market variables explain a lot of the differences between the two cities. The large number of (affordable) social dwellings in Amsterdam forms a significant contrast with the virtual lack of these dwellings in the Brussels area. Historical variables account for these different kinds of housing stock. Cultural variables, differences between and within the categories of Turks and Moroccans, can be seen as an additional explanatory factor for the segregation and concentration patterns of Turks and Moroccans in both cities.

Isolation, car ownership, and small area variation in incidence of acute lymphoblastic leukaemia in children.

To determine whether increased rates of childhood acute lymphoblastic leukaemia (ALL) which had been reported in isolated areas could be attributed to higher proportions of households owning cars, ecological analysis was performed with electoral wards as area units. Previous data were re-analysed using the proportion of households having no car, taken from the 1981 census of England and Wales, as an additional explanatory factor. A specialist registry of haematopoietic malignancies covering one-third of England and Wales (3270 electoral wards) recorded 438 cases of ALL in children diagnosed 1984-89, including 304 in the childhood peak (at ages 1-7 years). Relative risks were derived by Poisson regression of total childhood ALL and at ages 1-7 years for groups of electoral wards classified by isolation and car ownership. Multivariable analyses included adjustment for socio-economic status. No evidence of increased risk of childhood ALL in areas where more households own cars was found. ALL at ages 1-7 years was inversely associated with car ownership (risk in wards with least cars relative to those with most cars = 2.28, 95% CI: 1.12-4.64). The associations with geographic isolation persisted after allowing for car ownership (risks for ALL in young children in isolated relative to built-up areas = 2.19, 95% CI: 1.44-3.33). Levels of car ownership cannot explain the increased rates of childhood ALL which have been observed in isolated areas. No support has been found for a hypothesis relating these excesses to benzene exposure of children transported in cars. The previous explanation for the small area variation of childhood ALL in terms of geographical isolation and interpretation in terms of exposure to common infections continues to be justified.

Laboratory results for selected target organs in 138 individuals occupationally exposed to TCDD

Blood specimens for dioxin congener analysis and clinical laboratory studies were recently obtained for 138 employees who had been potentially exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) following a 1953 trichlorophenol autoclave accident. Results for 34 clinical tests were regressed on three exposure measures (current TCDD concentration, log TCDD concentration back-calculated to the time of exposure, and chloracne status). Age, smoking status and body-mass-index were included as additional explanatory factors in the analyses. Positive associations were found between each of the exposure measures and both serum thyroxine (T4) and throxine binding globulin (TBG). Additional exposure-response associations were detected relative to several immune system parameters, erythrocyte sedimentation rate, platelet count and serum alkaline phosphatase. These data will be specifically helpful in interpreting the results of additional morbidity and mortality studies conducted within the same target population.

A statistical trend analysis of revised Dobson total ozone data over the northern hemisphere

A seasonal trend analysis of Dobson total ozone data that have been critically reevaluated and revised is performed for 29 northern hemisphere stations located between 19°N and 64°N latitude using data through 1986. The trend model considered for these data allows for a different linear trend for each month of the year, so that the seasonal as well as the latitudinal and regional nature of the total ozone trend behavior can be examined. The trend model also incorporates the 10.7‐cm solar flux series and the 50‐hPa equatorial zonal wind series as additional explanatory factors for solar and quasi‐biennial oscillation induced ozone variations. Regression random effects models are then used for the individual station seasonal trend estimates to obtain trend estimates as a function of latitude for different seasons of the year. The results of this seasonal trend analysis indicate significantly more negative trends during the winter months (December‐March) than during the summer months (May–August), notably at higher latitudes, with the trends in winter becoming more negative with increasing latitude. The trends in the winter are estimated to be of the order of −1.2%, −2.1%, and −3.0% per decade for latitudes 35°N, 45°N, and 55°N, respectively, while trends during the summer are of the order of −0.6% per decade with no distinct pattern as a function of latitude. The year‐round or annual trend over all latitudes is estimated to be about −0.84±0.82% per decade. The trends are found to display some regional variation, with trends in Japan being considerably less negative than those in North America and Europe. Sensitivity studies are also performed to investigate the effects on ozone trend estimates due to certain factors such as abnormal ozone behavior in 1983 and 1985, the use of ozone data prior to 1965, and nuclear weapons testing in the early 1960s. The seasonal trend analysis is also performed using published (unrevised) Dobson data. Trend results based on published data are on average less negative than trends from revised Dobson data for European stations, by about 1.0% per decade across all seasons, with only small average differences for stations in North America and Japan.

Sex Differences in Distress: The Impact of Gender and Work Roles

Investigators have suggested that social roles, particularly gender roles, may explain the tendency for women to have higher rates of demoralization than men. Results of studies comparing employed women, employed men, and housewives have been mixed, however, and investigators have begun to consider additional explanatory factors. This paper focuses on a potential source of gender differences in distress that has received relatively little attention: the workplace itself. I consider the extent to which work conditions and the sexual segregation of occupations are related to two measures of distress: demoralization, which is more prevalent among women, and drinking, which is more prevalent among men. Multiple regression analyses indicate that the only work-related factors associated with demoralization are substantive complexity and full-time work, and these have an effect among women only. Full-time work and low levels of complexity are associated wiMh higher levels of demoralization among women. Substantive complexity is also associated with drinking, but only among men; as complexity declines, levels of drinking increase. These findings indicate the importance of considering work-related factors and measures of distress associated differentially with gender when investigating gender differences in distress.

Successive retention of funds, loan profitability and marketing implications in banking

This paper analyzes potential effects of successive retention of funds, induced by portions of funds granted as loans being successively redeposited via a chain of market transactions in the same bank, on loan profitability. It identifies sets of market conditions and loan terms under which the magnitude of the fund retention phenomenon could be significant, derives formulae to measure its magnitude, and suggests loan marketing strategies potentially capable of exploiting successive retention of funds to improve loan profitability. The potential role of the loan-induced retention process as an additional explanatory factor in the relationship between market structure and market performance in banking is also discussed.