Model Averaging Using Fractional Polynomials to Estimate a Safe Level of Exposure

Quantitative risk assessment involves the determination of a safe level of exposure. Recent techniques use the estimated dose-response curve to estimate such a safe dose level. Although such methods have attractive features, a low-dose extrapolation is highly dependent on the model choice. Fractional polynomials, basically being a set of (generalized) linear models, are a nice extension of classical polynomials, providing the necessary flexibility to estimate the dose-response curve. Typically, one selects the best-fitting model in this set of polynomials and proceeds as if no model selection were carried out. We show that model averaging using a set of fractional polynomials reduces bias and has better precision in estimating a safe level of exposure (say, the benchmark dose), as compared to an estimator from the selected best model. To estimate a lower limit of this benchmark dose, an approximation of the variance of the model-averaged estimator, as proposed by Burnham and Anderson, can be used. However, this is a conservative method, often resulting in unrealistically low safe doses. Therefore, a bootstrap-based method to more accurately estimate the variance of the model averaged parameter is proposed.     

Ungleichheit und Vorurteil

The authors take a look at how established sociological research in Germany deals with two distinct subjects: migrants in the German school system and New Fascists. The article highlights surprising, contrary feeling rules social scientists active in these two research areas develop regarding their objects of investigation. As it turns out in both cases social disintegration serves as an explanatory research frame. But feeling rules derived from this frame point in opposite directions. New Fascists are cast in the roles of victims of social change and institutional failure, thus calling for empathy and/or sympathy as the feeling to be directed towards them. Migrants, in contrast, are blamed for their situation, which invokes indifference and antipathy as a feeling rule. Comparing both research areas reveals how they connect to each other. Together they establish a dichotomous emotional regime which traces the lines of simultaneous inclusion in and exclusion from the German society.     

Socioeconomic and Gender Health Disparities in Diabetes: The Lower Middle Income Case of Ghana

While literature theorizing the relationship between socioeconomic status (SES), gender, and health outcomes is robust in high‐income countries, there is less scholarship examining how SES affects men and women in lower middle income countries (LMICs). Focusing on the LMIC case of Ghana, I use Wave 1 of the World Health Organization Study on Global Aging and Adult Health (SAGE) to examine the relationship between SES and diabetes among Ghanaian women and men. Specifically, I examine how key SES measures such as educational attainment, employment status, and income singly and collectively predict the odds of diabetes for Ghanaian men and women. I also examine the explanatory value of the reversal hypothesis, which posits that those of high SES experience higher rates of non‐communicable diseases. Overall, I find that while Ghanaian men experience increased odds of diabetes with increased education, Ghanaian women have higher odds of diabetes compared to men regardless of educational attainment. Understanding health patterns in LMICs like Ghana is important for sociological inquiry on health disparities seeking to incorporate more global perspectives.     

Sensuality as Subversion: Doing Masculinity with Chinese Australian Professionals

Within western gender structures, dominant discourses of Asian men as weak, feminized and asexual continue to render Asian masculinities subordinate to white hegemonic ideals. Although research of gender in organization studies has revealed important insights into how gender might be redone or undone, non‐white voices remain marginalized in this critical project. This article explores through in‐depth interviews the ways by which Chinese cis‐male professionals in Australia attempt to coopt desexualizing discourses and ‘do’ masculinity through sensuality. Specifically, the findings show how their sensuality is practised across various dimensions at work and beyond, including via the presentation of the self, relationships with others and representations in social texts. In presenting the voices of Asian men, this article seeks to illuminate their individual and collective pursuits for decolonization, agency and pleasure.     

Runtime and memory consumption analyses for machine learning R programs

R is a multi-paradigm language with a dynamic type system, different object systems and functional characteristics. These characteristics support the development of statistical algorithms at a high level of abstraction. Although R is commonly used in the statistics domain a big disadvantage are its runtime problems when handling computation-intensive algorithms. Especially in the domain of machine learning the execution of pure R programs is often unacceptably slow. Our long-term goal is to resolve these issues and in this contribution we used the traceR tool to analyse the bottlenecks arising in this domain. Here we measured the runtime and overall memory consumption on a well-defined set of classical machine learning applications and gained detailed insights into the performance issues of these programs.     

Untangling the commonalities and differences between domestic cross-regional experience and international experience in shaping speed of internationalization

Prior studies have paid attention to the influence of domestic experience on internationalization, for which domestic experience primarily refers to the accumulation of internationalization knowledge from industrial peers or partners at home. We argue that the commonalities and differences between international experience and domestic cross-regional experience have not been fully incorporated in previous frameworks in the literature. Thus, in untangling the commonalities, we purposively differentiate domestic experience into two dimensions, i.e., repetition-based experience and diversity-based experience, to investigate the contingent role of making domestic cross-regional investments in shaping the relationship between international experience and the speed of internationalization. We expect that these two dimensions of domestic experience will moderate the relationship between international experience and the speed of internationalization in a different way. More specifically, repetition-based experience has a negative moderating effect while diversity-based experience has a positive moderating effect. Further, considering the differences between international investments and domestic investments, we expect that the joint impacts of international experience and domestic cross-regional experience on internationalization speed are contingent on whether firms have sufficient resources to support multiple learning or whether institutions between the home country and foreign country is similar enough for cross-context application. We expect that financial slack and institutional distance between prior foreign entries' country and the home country play significant three-way moderating roles in setting boundaries for the relationship between domestic experience and international experience. Based on the analysis of 302 Chinese publicly listed firms from 2001 to 2014, the dynamic panel data regression results support our hypotheses. Overall, our simultaneous consideration of commonalities and differences between domestic investments and international investments sheds light on how MNCs learn from both international and domestic investments to speed up their foreign expansions.     

Children''s Exposure to Arsenic from CCA-Treated Wooden Decks and Playground Structures

CCA-treated wood is widely used in the fabrication of outdoor decks and playground equipment. Because arsenic can be removed from the surface of CCA-treated wood both by physical contact and by leaching, it is important to determine whether children who play on such structures may ingest arsenic in quantities sufficient to be of public health concern. Based on a review of existing studies, it is estimated that arsenic doses in amounts of tens of micrograms per day may be incurred by children having realistic levels of exposure to CCA-treated decks and playground structures. The most important exposure pathway appears to be oral ingestion of arsenic that is first dislodged from the wood by direct hand contact, then transferred to the mouth by children's hand-to-mouth activity. The next most important pathway appears to be dermal absorption of arsenic, while ingestion of soil that has become contaminated by leaching from CCA-treated structures appears to be of lesser importance, except possibly in the case of children with pica. Considerable uncertainty, however, is associated with quantitative estimates of children's arsenic exposure from CCA-treated wood. Priorities for refining estimates of arsenic dose include detailed studies of the hand-to-mouth transfer of arsenic, studies of the dermal and gastrointestinal absorption of dislodgeable arsenic, and studies in which doses of arsenic to children playing in contact with CCA-treated wood are directly determined by measurement of arsenic in their urine, hair, and nails.     

Resistance training is linked to heightened positive motivational state and lower negative affect among healthy women aged 65–70

Resistance training (RT) improves overall health, but the psychological effects of RT in healthy old adults have not been tested. The aim of this study was to investigate a sample of 65–70-year-old healthy and physically active women to assess their sense of coherence, health-related quality of life, hope, and affect, before and after taking part in a 24-week RT intervention (N = 14), compared to controls (N = 18). Findings showed a significant increase in hope (p = 0.013) and a significant decrease in negative affect (p = 0.002). Starting RT after age 65 does not appear to negatively impact on women’s psychological health but seems to be associated with important psychological health benefits.