A Geologically Based Indoor-Radon Potential Map of Kentucky

We combined 71,930 short-term (median duration 4 days) home radon test results with 1:24,000-scale bedrock geologic map coverage of Kentucky to produce a statewide geologically based indoor-radon potential map. The test results were positively skewed with a mean of 266 Bq/m3, median of 122 Bq/m3, and 75th percentile of 289 Bq/m3. We identified 106 formations with ≥10 test results. Analysis of results from 20 predominantly monolithologic formations showed indoor-radon concentrations to be positively skewed on a formation-by-formation basis, with a proportional relationship between sample means and standard deviations. Limestone (median 170 Bq/m3) and dolostone (median 130 Bq/m3) tended to have higher indoor-radon concentrations than siltstones and sandstones (median 67 Bq/m3) or unlithified surficial deposits (median 63 Bq/m3). Individual shales had median values ranging from 67 to 189 Bq/m3; the median value for all shale values was 85 Bq/m3. Percentages of values falling above the U.S. Environmental Protection Agency (EPA) action level of 148 Bq/m3 were sandstone and siltstone: 24%, unlithified clastic: 21%, dolostone: 46%, limestone: 55%, and shale: 34%. Mississippian limestones, Ordovician limestones, and Devonian black shales had the highest indoor-radon potential values in Kentucky. Indoor-radon test mean values for the selected formations were also weakly, but statistically significantly, correlated with mean aeroradiometric uranium concentrations. To produce a map useful to nonspecialists, we classified each of the 106 formations into five radon-geologic classes on the basis of their 75th percentile radon concentrations. The statewide map is freely available through an interactive internet map service

Psychogenic tremors

We diagnosed 24 patients, 9 men and 15 women ranging in age from 15 to 78 years, with clinically established or documented psychogenic tremors. Clinical presentations were unique, with complex tremors (often resting, postural, and kinetic), unusual temporal profiles (abrupt onset with a variable course), absence of other neurologic signs, inconsistent and incongruous symptomatology, selective disability with ability to perform some functions despite severe tremors, distractibility that lessens or abolishes tremor, atypical tremorgraphic recordings with changing amplitude and frequency, unusual handwriting and drawing specimens, presence of multiple undiagnosed somatizations, unresponsiveness to all treatments, absence of documented disease by laboratory or radiographic tests, presence of psychiatric disease, spontaneous remissions, or recovery with psychotherapy. We present criteria for the diagnosis of psychogenic tremor.</jats:p

Molecular Weight and Association of Asphaltenes: a Critical Review

The determination of asphaltene molecular weights is complicated by the tendency of asphaltene molecules to associate with each other and with other petroleum constituents, and reported molecular weights vary from 900 to 300 000. This paper reviews the methods (vapor pressure osmometry, size exclusion chromatography, ultrafiltration, ultracentrifugation, viscosity, small angle X-ray scattering, infrared spectroscopy, solubilization, and interfacial tension) that have been used to estimate asphaltene molecular weights and to probe association phenomena. It is concluded that asphaltene fractions from typical crudes have a number average molecular weight of 1 200-2 700 and a molecular weight range of 1,000-10,000 or higher. Intermolecular association phenomena are primarily responsible for observed molecular weights up to and in excess of 100,000 but detailed mechanisms of the intermolecular associations are not well understood. Certain observations suggest that asphaltene molecules are associated in reversedmicelles and that asphaltenes interact selectively with resins although the evidence on these points is subject to alternate interpretations. H-bond interactions between asphaltenes and resins have been demonstrated

Is it Better to be a Boy? A Disaggregated Outlay Equivalent Analysis of Gender Bias in Papua New Guinea

The demographic evidence of gender bias in many countries has provided an impetus for finding ways to study the status of women in developing countries. Because of the lack of accurate intra-household data, Deaton [1989] introduced a method for using household expenditure data to infer discrimination in the allocation of goods between boys and girls. Few studies of discrimination using the method, however, have detected bias even though alternative indicators suggest it is a serious problem. In this paper, we study the case of Papua New Guinea, a country in which there are many indicators of severe gender bias. Discrimination in the allocation of goods between boys and girls within households in Papua New Guinea is examined using Deaton's outlay-equivalent ratio method. Adding a boy to the household reduces expenditure on adult goods by as much as would a nine-tenths reduction in total outlay per member, but girls have no effect on adult goods expenditure. The hypothesis of Haddad and Reardon [1993] that gender bias is inversely related to the importance of female labour in agricultural production is not supported. Sensitivity analysis shows that bias in rural areas occurs equally regardless of the age of the household head, while bias against girls may be less in regions of the country that have ethnic groups which practice matrilineal descent.

An Investigation of the Household Economy: Coffee Production and Gender Relations in Papua New Guinea

Using two years of intra-household data from one area of the Papua New Guinea Highlands this article examines the impact of gender relations on household coffee production. Poor relative labour returns for women and the unequal distribution of tasks within the household were found to exert considerable influence on the level of household success in cultivating coffee. The article concludes with the construction of a model linking the intra-household distribution of economic benefits, determinants of household resource allocation and underdevelopment.