An Empirical Approach to Sufficient Similarity: Combining Exposure Data and Mixtures Toxicology Data

When assessing risks posed by environmental chemical mixtures, whole mixture approaches are preferred to component approaches. When toxicological data on whole mixtures as they occur in the environment are not available, Environmental Protection Agency guidance states that toxicity data from a mixture considered “sufficiently similar” to the environmental mixture can serve as a surrogate. We propose a novel method to examine whether mixtures are sufficiently similar, when exposure data and mixture toxicity study data from at least one representative mixture are available. We define sufficient similarity using equivalence testing methodology comparing the distance between benchmark dose estimates for mixtures in both data‐rich and data‐poor cases. We construct a “similar mixtures risk indicator”(SMRI) (analogous to the hazard index) on sufficiently similar mixtures linking exposure data with mixtures toxicology data. The methods are illustrated using pyrethroid mixtures occurrence data collected in child care centers (CCC) and dose‐response data examining acute neurobehavioral effects of pyrethroid mixtures in rats. Our method shows that the mixtures from 90% of the CCCs were sufficiently similar to the dose‐response study mixture. Using exposure estimates for a hypothetical child, the 95th percentile of the (weighted) SMRI for these sufficiently similar mixtures was 0.20 (i.e., where SMRI <1, less concern; >1, more concern).     

Labour Underutilisation and Gender: Unemployment Versus Hidden-Unemployment

As labour markets have become more complex there has been increasing interest among researchers in understanding the ways that social and labour market processes and contexts impact on various labour market states. One important area has been in understanding the differences between unemployment and hidden unemployment. This paper considers the ways in which these two labour market states differ for a sample of male and female respondents to the Household Income and Labour Dynamics Australia (HILDA) survey. It presents data related to the reasons why respondents in these two labour force states consider they are jobless and analyses the characteristics of male and female respondents in the two labour market states to consider differences in outcomes. The findings suggest that there are differences in the two states of labour market outcomes and that these are further complicated when one considers processes for males and females.     

Sexual Frequency and the Stability of Marital and Cohabiting Unions

Prior research found that lower sexual frequency and satisfaction were associated with higher rates of divorce, but little research had examined the role of sexual activity in the dissolution of cohabiting unions. We drew upon social exchange theory to hypothesize why sexual frequency is more important in cohabitation: (a) cohabitors' lower costs of finding sexual alternatives, (b) cohabitors' lower barriers to ending the relationship in the form of union‐specific economic and noneconomic capital, and (c) cohabitors' higher expectations for sexual activity. Using the National Survey of Families and Households (N = 5,902), we examined the relationship between sexual frequency and union dissolution. Results indicated that low sexual frequency was associated with significantly higher rates of union dissolution among cohabitors than married couples.     

A counterexample to a conjecture of Schwartz

In 1990, motivated by applications in the social sciences, Thomas Schwartz made a conjecture about tournaments which would have had numerous attractive consequences. In particular, it implied that there is no tournament with a partition A, B of its vertex set, such that every transitive subset of A is in the out-neighbour set of some vertex in B, and vice versa. But in fact there is such a tournament, as we show in this article, and so Schwartz’ conjecture is false. Our proof is non-constructive and uses the probabilistic method.     

The fertility of teachers in England and Wales

Data on the fertility of teachers in grant earning schools in England and Wales were collected in 1955 as part of a general survey into the social characteristics of teachers. The survey was financed by the Nuffield Foundation with a contribution from the Population Investigation Committee. A subsequent article will discuss some possible determinants of fertility and in particular the interrelationship between social mobility and fertility. The present note describes changes in cohort fertility of teachers since 1915 and compares average family size with that of other sections of the population. The average number of children per married male teacher declined from 1.81 for the pre-1920 cohort to 1.47 for 1930–34. Segmental data after 1935 indicate a rise to approximately 2 children per family. Comparison with the Family Census suggests that the number of children of teachers is between 10% and 20% below that of all professions combined when the age at marriage of the wife is taken into account.     

The Relationship Between Aversive Conditioning and Risk-avoidance in Gambling

This study investigated the relationship between aversive conditioning, heart rate variability suppression, behavioral activation system/behavioral inhibition system and risk-avoidance on the Iowa gambling task (IGT) in a nonclinical sample (29 male, 29 female, mean age = 20.7). A laboratory based Pavlovian aversive conditioning paradigm was used where a 1500 Hz tone (CS+) was followed by a burst of loud white noise (US), and a 850 Hz (CS−) tone was never followed by the US. In a subsequent extinction phase where the CS+ and CS− were presented without the US, conditioned skin conductance responses to the CS+ indicated aversive conditioning. The results showed that the participants who did not show aversive conditioning (N = 26) exhibited significantly less risk-avoidance compared to participants who did show aversive conditioning (N = 32). Regression analysis showed that among the study variables, only aversive conditioning contributed significantly to explaining variance in risk-avoidance. These results may have implications for understanding risk-taking in gambling in general, and may be a starting point understanding the role of aversive conditioning in the development and maintenance of gambling problems.     

Revisions of the Fish Invasiveness Screening Kit (FISK) for its Application in Warmer Climatic Zones,with Particular Reference to Peninsular Florida

The initial version (v1) of the Fish Invasiveness Scoring Kit (FISK) was adapted from the Weed Risk Assessment of Pheloung, Williams, and Halloy to assess the potential invasiveness of nonnative freshwater fishes in the United Kingdom. Published applications of FISK v1 have been primarily in temperate‐zone countries (Belgium, Belarus, and Japan), so the specificity of this screening tool to that climatic zone was not noted until attempts were made to apply it in peninsular Florida. To remedy this shortcoming, the questions and guidance notes of FISK v1 were reviewed and revised to improve clarity and extend its applicability to broader climatic regions, resulting in changes to 36 of the 49 questions. In addition, upgrades were made to the software architecture of FISK to improve overall computational speed as well as graphical user interface flexibility and friendliness. We demonstrate the process of screening a fish species using FISK v2 in a realistic management scenario by assessing the Barcoo grunter Scortum barcoo (Terapontidae), a species whose management concerns are related to its potential use for aquaponics in Florida. The FISK v2 screening of Barcoo grunter placed the species into the lower range of medium risk (score = 5), suggesting it is a permissible species for use in Florida under current nonnative species regulations. Screening of the Barcoo grunter illustrates the usefulness of FISK v2 as a proactive tool serving to inform risk management decisions, but the low level of confidence associated with the assessment highlighted a dearth of critical information on this species.     

Partisan Political Identification among White Ethnic Groups: An Historical Analysis

Abstract

This article presents evidence and argument dealing with partisan political identification among white ethnic groups. Recently, numerous political commentators and analysts have argued that the ethnic-labor component of the New Deal coalition is in the midst of collapse and decay, and that white ethnics are re-aligning with the Republican Party. Through an analysis of public opinion data gathered between 1936 and 1974, the partisan re-alignment theory is critically examined. The data show little or no support for the idea that Catholic and Jewish ethnics are identifying more closely with the Republican Party. Data show that degree of identification with the Democrats is nearly the same in 1974 as it was in 1936.     

调整“大地依恋”的层级:关注跨层级思维的艺术表达

当代"场所"理论的建构陷入僵局,人们各持己见,而跨层级思维则有利于培育新的"场所感"范式。跨层级思维指在不同的场所层级之间来回转换,反复变焦,把地方-全球讨论置于"层级"和"依恋"语境中。当前许多环境文本如摄影作品、著作等都运用调整"大地依恋"层级的策略,帮助当代读者以多种视角理解自我与场所的深层联系。跨层级思维意味着将对某一特定场所体验的精微性与对全球体验的广大性结合起来,理解人们的生活给环境带来的真实影响,培育新的也许是有效应对当今世界严峻现实的认知习惯与思维方式,使人们适应变化中的世界,并促使他们克服对可能令人麻痹的抽象问题视而不见的倾向。