Critical Radionuclide/Critical Pathway Analysis for the U.S. Department of Energy's Savannah River Site

Many different radionuclides have been released to the environment from the Savannah River Site (SRS) during the facility's operational history. However, as shown by this analysis, only a small number of the released radionuclides have been significant contributors to potential doses and risks to off-site people. This article documents the radiological critical contaminant/critical pathway analysis performed for SRS. If site missions and operations remain constant over the next 30 years, only tritium oxide releases are projected to exceed a maximally exposed individual (MEI) risk of 1.0E-06 for either the airborne or liquid pathways. The critical exposure pathways associated with site airborne releases are inhalation and vegetation consumption, whereas the critical exposure pathways associated with liquid releases are drinking water and fish consumption. For the SRS-specific, nontypical exposure pathways (i.e., recreational fishing and deer and hog hunting), cesium-137 is the critical radionuclide.     

How Does the Gender of Parents Matter?

Claims that children need both a mother and father presume that women and men parent differently in ways crucial to development but generally rely on studies that conflate gender with other family structure variables. We analyze findings from studies with designs that mitigate these problems by comparing 2‐parent families with same or different sex coparents and single‐mother with single‐father families. Strengths typically associated with married mother‐father families appear to the same extent in families with 2 mothers and potentially in those with 2 fathers. Average differences favor women over men, but parenting skills are not dichotomous or exclusive. The gender of parents correlates in novel ways with parent‐child relationships but has minor significance for children's psychological adjustment and social success.     

Limits to social capital: comparing network assistance in two New Orleans neighborhoods devastated by Hurricane Katrina

Sociological research emphasizes that personal networks offer social resources in times of need and that this capacity varies by the social position of those involved. Yet rarely are sociologists able to make direct comparisons of such inequalities. This study overcomes this methodological challenge by examining network activation among residents of two unequal neighborhoods severely devastated by Hurricane Katrina. Results indicate that local network capacities of Lower Ninth Ward residents relative to those of the more affluent Lakeview neighborhood dissipated before, during, and after the disaster to erode the life chances of individual residents and the neighborhood they once constituted.     

Using Malmquist Indexes to measure changes in the productivity and efficiency of US accounting firms before and after the Sarbanes–Oxley Act

There have been many criticisms of the Sarbanes–Oxley (SOX) Act passed in July of 2002 to correct business accountability and performance practices. The act has a major emphasis on accounting and its practices. This paper attempts a response to these criticisms by investigating changes in productive efficiency for 62 of the largest US public accounting firms between the periods (2000–2001) and (2003–2004)—the periods before and after enactment of SOX in July of 2002. DEA is used to calculate Malmquist indexes of productivity and efficiency changes. This index is used because it can distinguish between changes in technical efficiency, which limit the possibilities, and changes in the performance efficiencies for each firm. Contrary to many of the criticisms, results indicate that accounting firms have exhibited significant post SOX growth in productive efficiency which is better than pre-SOX performances.     

Finding the maximum efficiency for multistage ranked-set sampling

Multistage ranked-set sampling (MRSS) is a generalization of ranked-set sampling in which multiple stages of ranking are used. It is known that for a fixed distribution under perfect rankings, each additional stage provides a gain in efficiency when estimating the population mean. However, the maximum possible efficiency for the MRSS sample mean relative to the simple random sampling sample mean has not previously been determined. In this paper, we provide a method for computing this maximum possible efficiency under perfect rankings for any choice of the set size and the number of stages. The maximum efficiency tends to infinity as the number of stages increases, and, for large numbers of stages, the efficiency-maximizing distributions are symmetric multi-modal distributions where the number of modes matches the set size. The results in this paper correct earlier assertions in the literature that the maximum efficiency is bounded and that it is achieved when the distribution is uniform.