Hypothesis testing, power and sample size determination for between group comparisons in fMRI experiments

Modern methods for imaging the human brain, such as functional magnetic resonance imaging (fMRI) present a range of challenging statistical problems. In this paper, we first develop a large sample based test for between group comparisons and use it to determine the necessary sample size in order to obtain a target power via simulation under various alternatives for a given pre-specified significance level. Both testing and sample size calculations are particularly critical for neuroscientists who use these new techniques, since each subject is expensive to image.     

Presenting DEA graphically

This paper introduces a methodology that permits presentation of the results of data envelopment analysis (DEA) graphically. A specialized form of multi-dimensional scaling, Co-Plot, enables presentation of the DEA results in a two-dimensional space, hence in a clear, understandable manner. When plotting ratios rather than original data, DEA efficient units can be visualized clearly, as well as their connections to specific variables and/or ratios. Furthermore, Co-Plot can be used in an exploratory data analysis to identify outliers, whose data require additional scrutiny, and potentially inconsequential variables that could be aggregated or removed from the analysis with little effect on the subsequent DEA results.     

Understanding the role of facial asymmetry in human face identification

Face recognition has important applications in forensics (criminal identification) and security (biometric authentication). The problem of face recognition has been extensively studied in the computer vision community, from a variety of perspectives. A relatively new development is the use of facial asymmetry in face recognition, and we present here the results of a statistical investigation of this biometric. We first show how facial asymmetry information can be used to perform three different face recognition tasks—human identification (in the presence of expression variations), classification of faces by expression, and classification of individuals according to sex. Initially, we use a simple classification method, and conduct a feature analysis which shows the particular facial regions that play the dominant role in achieving these three entirely different classification goals. We then pursue human identification under expression changes in greater depth, since this is the most important task from a practical point of view. Two different ways of improving the performance of the simple classifier are then discussed: (i) feature combinations and (ii) the use of resampling techniques (bagging and random subspaces). With these modifications, we succeed in obtaining near perfect classification results on a database of 55 individuals, a statistically significant improvement over the initial results as seen by hypothesis tests of proportions.     

Becoming a New Farmer: Agrarianism and the Contradictions of Diverse Economies*

A resurgence of agrarianism has motivated new farmers to enter farming, not for profit, but for lifestyle and socio‐ecological values which are frequently associated with diverse economies. Proponents of diverse economies argue for an ontological reframing that accounts for non‐capitalist forms of economic exchange. However, these perspectives have not fully addressed the conditions—often structured by race and class—that facilitate participation in diverse economies. This paper is based on mixed‐methods research on the life cycle of new farmers in Hawai‘i that include participants of farmer training programs. We investigate what drives new farmers into farming, by what mechanisms they are able (or not) to establish a farm, and what limits the duration of their participation. Our analysis reveals three contradictions of diverse economies in agriculture: (1) the inadvertent undervaluation of farmwork that undermines broader efforts to improve the welfare of farm labor; (2) the tension between the value of scaling up and the vulnerability of cooptation; and (3) the ways in which the duration of new farmers' engagement is structured by their ability to mobilize unpaid labor and external resources. These contradictions challenge long‐term and inclusive participation in diverse economies in ways that constrain their emancipatory potential.     

The Social and Spatial Stratification of Vaccinal Patterns in Berlin Following Re‐Unification

Efforts by health authorities to stress the importance of herd immunity in the light of a resurgence of seemingly vanquished childhood diseases have frequently met with poor response rates. Investigating whether reunified Berlin can achieve a desirable herd immunity of 80% ‐ 85% against diphtheria, this paper examines the potential influence of socio‐demographic variables (age, gender, social circumstances, migration background) on vaccine‐uptake. Secondly, it investigates historically diverging vaccinal policies in Berlin as well as recent changes to monitoring coverage in their effect on immunisation‐related behaviour.     

Does the desire to conform to peers moderate links between popularity and indirect victimization in early adolescence?

This study of 426 Canadian early adolescents (M_age = 12.52; 53% girls) investigated whether associations between popularity and indirect victimization (i.e., reputational victimization, exclusion) varied as a function of gender and the desire to conform to characteristics and competencies that are valued within the peer group (i.e., peer conformity goals). Regression analyses revealed popularity was uniquely and positively associated with reputational victimization, but was not significantly related to exclusion after accounting for the effects of meanness and likeability. The associations between popularity and indirect victimization were moderated by peer conformity goals and gender. The results indicated that popular girls with high peer conformity goals experienced more reputational victimization and exclusion than popular girls with low peer conformity goals. However, popular boys with high peer conformity goals experienced less exclusion than popular boys with low peer conformity goals. The findings suggest that peer conformity goals carry with them some risks for popular girls, but may serve a protective function for popular boys.     

Opportunities Missed

This paper places Stephen Mitchell's two early papers on homosexuality in historical context and explores why they were relatively unknown in their time, despite this author's belief that they contain the essential ideas for changing the way psychoanalysts understand homosexuality and work clinically with gay patients. The papers contain the needed truths; but, because of entrenched antihomosexual bias in the psychoanalytic world, activism was necessary before the truth could be heard.     

Facebook Bras and #digitalharems: Fantasies of Mimesis and the Transgressions of Aliaa Elmahdy and Amina Sboui

Abstract

This article presents a horizontal reading of Aliaa Elmahdy's and Amina Sboui's corporeal interventions alongside the efficacy of digital platforms in order to consider how algorithmic and normative protocols related to content filtering on social media amplify certain forms of political communication while prohibiting others. I argue that readings of Elmahdy's and Sboui's bodily politics through the lens of liberal feminism rely on what I call discourses of mimetic networking, where particular mediated events become reterritorialized as part of an archival knowledge of ‘Arabness’. This is done through the organization of data via hashtagging and content moderation, and through rhetorics of techno-optimism that mirror ‘first contact’ narratives which gender, racialize, and flatten complex and fluid engagements with new media in non-US/European contexts. The article concludes with a consideration of how the persistence of their corporeality relays with both normative and programmatic parameters online to make alternative visions of communication possible.