Analytical approximations for iterated bootstrap confidence intervals

Standard algorithms for the construction of iterated bootstrap confidence intervals are computationally very demanding, requiring nested levels of bootstrap resampling. We propose an alternative approach to constructing double bootstrap confidence intervals that involves replacing the inner level of resampling by an analytical approximation. This approximation is based on saddlepoint methods and a tail probability approximation of DiCiccio and Martin (1991). Our technique significantly reduces the computational expense of iterated bootstrap calculations. A formal algorithm for the construction of our approximate iterated bootstrap confidence intervals is presented, and some crucial practical issues arising in its implementation are discussed. Our procedure is illustrated in the case of constructing confidence intervals for ratios of means using both real and simulated data. We repeat an experiment of Schenker (1985) involving the construction of bootstrap confidence intervals for a variance and demonstrate that our technique makes feasible the construction of accurate bootstrap confidence intervals in that context. Finally, we investigate the use of our technique in a more complex setting, that of constructing confidence intervals for a correlation coefficient.     

How the British Working Class Became White: The Symbolic (Re)formation of Racialized Capitalism

This article offers an explanation of how and why the British working class, from being marginal to white identity in the nineteenth century, came to adopt and adapt this identity in the twentieth century. The changing position of whiteness within the symbolic constitution of capitalism is discussed. More specifically, the transition from whiteness as bourgeois identity within Victorian, relatively laissez-faire, capitalism to whiteness as a popular, or mass, identity, within the more state interventionist capitalism of the twentieth century is used to exemplify the mutable nature, and political complexities, of the relationship between working class and white identities. The paper concludes with some observations on the implications of this argument for the theory and practice of anti-racism.     

Importance of interpolation when constructing double-bootstrap confidence intervals

We show that, in the context of double-bootstrap confidence intervals, linear interpolation at the second level of the double bootstrap can reduce the simulation error component of coverage error by an order of magnitude. Intervals that are indistinguishable in terms of coverage error with theoretical, infinite simulation, double-bootstrap confidence intervals may be obtained at substantially less computational expense than by using the standard Monte Carlo approximation method. The intervals retain the simplicity of uniform bootstrap sampling and require no special analysis or computational techniques. Interpolation at the first level of the double bootstrap is shown to have a relatively minor effect on the simulation error.     

A Social Networks Approach to Public Relations on Twitter: Social Mediators and Mediated Public Relations

This study proposes theoretical and practical frameworks to systematically examine mediated public relations in social media spaces. We applied a social network conceptual framework to identify and characterize social mediators that connect the US State Department with its international public. The results showed that social mediators vary in terms of their formality and interdependence. Formal social mediators were primarily US government agencies while informal social mediators were nongovernmental organizations (NGOs) and individuals. Notably, relationships with populations in the Middle East and North Africa were mediated primarily by informal actors, and formal mediators played a key role in connecting the public with everywhere else in the world. Government-related formal mediators and informal social mediators showed similar levels of bilateral relationships. In contrast, news media, the most traditional public relations mediators, were rarely found as social mediators and demonstrated the most unilateral relationships.     

Specific Organizational Citizenship Behaviours and Organizational Effectiveness: The Development of a Conceptual Heuristic Device

Organizational citizenship behaviour has generally been associated with organizational effectiveness. However, recent research has shown that this may not always be the case and that certain types of organizational citizenship behaviour such as compulsory citizenship behaviour, may be inimical to the fulfillment of formal goals and organizational effectiveness. Using military historical and business organizational secondary data, the paper maintains that extreme variance in either organizational (task) or personal (social psychological) support organizational citizenship behaviour generates entropic citizenship behaviour which derails completely the effective accomplishment of formal organizational goals. A general model of organizational citizenship behaviour with entropic citizenship behavior as its novel conceptual boundary is developed in the paper, and four specific propositions with implications for future empirical research are delineated.     

Property,gender and the life course: Inheritance and family welfare provision in early nineteenth-century England

Drawing upon detailed research of inheritance practices in early nineteenth-century Stockport, this article examines how married men attempted to provide for their families after their death. It is argued that inheritance acted as an informal family welfare mechanism through which specific gender relations associated with middle-class households were reproduced. The evidence presented suggests that married male testators often used inheritance to try and 'fix' their wives into widowhood. Widows were frequently required to act as custodians of family property and maintain the domestic order. Access to property was carefully controlled and various legal devices were used to give authority to the process and ensure that the estate was used by widows to care and provide for children in certain, carefully stipulated ways. In making these claims, the article argues that recent revisionist studies that have attempted to highlight the proprietorial autonomy of middle-class women in industrializing communities ignore the forces at work which constrained the free use of property by women at certain stages in the life course. The findings of the study are also used to highlight the ways in which middle-class men's uses of property were materially and ideologically 'constrained'.     

The effects of a continuous passive motion device on myoelectric activity of the erector spinae during prolonged sitting at a computer workstation

Continuous passive motion (CPM) has been proposed as a method to help individuals with low back pain cope with prolonged sitting. The purpose of this study was to investigate the effects that a commercially available CPM device had on lumbar and thoracic erector spinae (ES) muscle activation (using surface electromyography, "EMG"), and on subjective discomfort during prolonged seated computer work with and without the use of the CPM device. There were no significant differences in average ES muscle activation levels, amplitude probability distribution functions, and EMG gaps number and length when sitting with the CPM device was compared to sitting normally. Subjective ratings of discomfort were also not significantly different between the two sitting conditions. The results indicated that there were no clear mechanisms by which the CPM device may reduce ES muscle pain and fatigue for the tasks and pain-free individuals studied.     

Clinical trials integrity: a CRO perspective

When contract research organizations (CROs) were first formed, pharmaceutical companies outsourced to them only certain aspects of the conduct of their clinical trials. At first CROs were highly specialized entities, providing, for example, either biostatistical advice, clinical research associates who monitored investigational sites for regulatory compliance, or regulatory support. Gradually, full service CROs emerged, offering a full range of services for clinical trials, including the selection of investigators and investigational sites, assistance with patient recruitment, safety surveillance and reporting, site audits, and data management and biostatistics. This evolving relationship between CROs and the pharmaceutical and medical device industries has resulted in CROs assuming more and more of the regulatory and ethical risks and responsibilities inherent in the conduct of clinical trials. In this full service role, CROs, unlike sponsors, are not interested in the outcome of study, but like sponsors, are subject to heavy regulation by the federal government, must follow applicable state laws, must respect international guidelines, and are obliged to follow their own operating procedures. Moreover, they are judged by the industry on the basis of the scope and quality of services provided, including the degree of adherence to the research protocol, regulatory requirements, and timelines; the quality of the professional working relationships with investigators and institutions, both academic and community-based; and the validity of the data. Further, CROs are subject to comprehensive audits by sponsoring companies, FDA, and other regulatory authorities. For all these reasons, CROs are being tasked with strict vigilance of all stages of the clinical trial process to ensure that the laws, regulations, and industry standards designed for the protection of human subjects and data integrity are maintained.     

Individual and crossover effects of stress on adjustment in medical student marriages

High-stress individuals may benefit from social support, although their support providers may be adversely affected via stress crossover effects. Individual and crossover effects of perceived stress within medical student marriages (n = 30) were investigated. Perceived spousal support was positively associated with individuals' own marital and emotional adjustment, attenuating stress effects. With regard to crossover effects, medical students' perceived stress was significantly associated with their spouses' emotional adjustment. Further, medical students' own emotional adjustment fully mediated this crossover effect. Results suggest that the contagion of negative affect may serve as a key mechanism through which stress crossover effects operate in marriage.     

Sovereignty at What Scale? An Inquiry into Multiple Dimensions of Food Sovereignty

Abstract

Food sovereignty has struggled to make inroads into changing the structures and processes underlying the corporate food regime. One reason is that scale is still underspecified in the politics, strategies, and theories of food sovereignty. We suggest that much can be learned from examining the multiple dimensions of scale inherent in ongoing food sovereignty struggles. A gap exists between these in vivo experiments and the maturing academic theory of scale. The concept of ‘sovereignty’ can be opened up to reveal that movements, peoples, and communities, for example, are creating multiple sovereignties and are exercising sovereignty in more relational ways. Relational scale can aid movements and scholars to map and evaluate how spatial and temporal processes at and among various levels work to reinforce dominant agri-food systems but could also be reconfigured to support progressive alternatives. Finally, we apply relational scale to suggest practical strategies for realizing food sovereignty, using examples from the Potato Park in the Peruvian Andes.