Switching on and off … : Does smartphone use obstruct the possibility to engage in recovery activities?

This study examines the impact of work-related smartphone use on daily recovery from work-related efforts. The literature shows that work–home interference (WHI) is an important inhibitor of the recovery process. We propose that the extensive use of smartphones with its implicit request of 24/7 availability inhibits the process of engaging in activities that are required for daily recovery. A total of 80 employees (40 smartphone users, 40 controls) completed a 6-day diary questionnaire over a time period of 2 weeks. Contrary to our hypothesis, smartphone users did not experience more overall WHI than nonusers. Furthermore, four activities aimed at recovery were examined. We predicted that daily WHI would increase employees’ engagement in recovery activities, but only if they did not use a smartphone. Results showed that, for the control group, WHI was positively related to psychological detachment, relaxation, mastery, and control activities, whereas smartphone users facing high WHI did not succeed in engaging in these recovery activities. This implies that being connected to work in the evening hours through smartphones has consequences for the extent to which employees succeed in undertaking recovery activities.     

Complete axiomatizations for XPath fragments

We provide complete axiomatizations for several fragments of Core XPath, the navigational core of XPath 1.0 introduced by Gottlob, Koch and Pichler. A complete axiomatization for a given fragment is a set of equivalences from which every other valid equivalence is derivable; equivalences can be thought of as (undirected) rewrite rules. Specifically, we axiomatize single axis fragments of Core XPath as well as full Core XPath. Our completeness proofs use results and techniques from modal logic.     

Expressivity of Second Order Propositional Modal Logic

We consider second-order propositional modal logic (SOPML), an extension of the basic modal language with propositional quantifiers introduced by Kit Fine in 1970. We determine the precise expressive power of SOPML by giving analogues of the Van Benthem–Rosen theorem and the Goldblatt Thomason theorem. Furthermore, we show that the basic modal language is the bisimulation invariant fragment of SOPML, and we characterize the bounded fragment of first-order logic as being the intersection of first-order logic and SOPML.     

Reading between the lies: identifying concealed and falsified emotions in universal facial expressions

The widespread supposition that aspects of facial communication are uncontrollable and can betray a deceiver's true emotion has received little empirical attention. We examined the presence of inconsistent emotional expressions and "microexpressions" (1/25-1/5 of a second) in genuine and deceptive facial expressions. Participants viewed disgusting, sad, frightening, happy, and neutral images, responding to each with a genuine or deceptive (simulated, neutralized, or masked) expression. Each 1/30-s frame (104,550 frames in 697 expressions) was analyzed for the presence and duration of universal expressions, microexpressions, and blink rate. Relative to genuine emotions, masked emotions were associated with more inconsistent expressions and an elevated blink rate; neutralized emotions showed a decreased blink rate. Negative emotions were more difficult to falsify than happiness. Although untrained observers performed only slightly above chance at detecting deception, inconsistent emotional leakage occurred in 100% of participants at least once and lasted longer than the current definition of a microexpression suggests. Microexpressions were exhibited by 21.95% of participants in 2% of all expressions, and in the upper or lower face only.     

Intimate Distance: Rethinking the Unthought God in Christianity

The work of the French philosopher Jean-Luc Nancy shares with the thinkers of the ‘theological turn in phenomenology’ the programmatic desire to place the ‘theological’, in the broad sense of rethinking the religious traditions in our secular time, back on the agenda of critical thought. Like those advocating a theological turn in phenomenology, Nancy’s deconstructive approach to philosophical analysis aims to develop a new sensibility for the other, for transcendence, conceptualized as the non-apparent in the realm of appearing phenomena. This is why Nancy launches a project looking for the ‘unthought’ and unexpected within the Christian traditions, called deconstruction of Christianity. However, the deconstructive approach to the non-apparent differs fundamentally from that of the thinkers of the turn (1) in its being non-apologetic and non-restorative with regard to religion, because it starts from a problematization of the—typically modern, that is romantic—desire to defend and protect what would be ‘lost’ and possibly to restore this, (2) in its focus on the complex difference-at-work (différance) between religion and secularism, a difference that can be termed entanglement and complicity between these two, (3) in its hypothesis that this entanglement is essentially one between (the meaning and experience of, the rituality around) presence and absence in modern culture, (4) in its conviction that the philosophy and history of culture must join, support, complete and maybe even turn around phenomenology when dealing with the difficult task of determining what exactly would be ‘left’ of the ‘theological’ in our time. In this article, both positions are compared and confronted further, leading to an account of Nancy’s re-readings of the Christian legacy (its theology, doctrine, art, rituals etc.), and ending in a more detailed, exemplary inquiry into the tension between distance and proximity, characteristic of the Christian God.

Statistical inference of minimum rank factor analysis

For any given number of factors, Minimum Rank Factor Analysis yields optimal communalities for an observed covariance matrix in the sense that the unexplained common variance with that number of factors is minimized, subject to the constraint that both the diagonal matrix of unique variances and the observed covariance matrix minus that diagonal matrix are positive semidefinite. As a result, it becomes possible to distinguish the explained common variance from the total common variance. The percentage of explained common variance is similar in meaning to the percentage of explained observed variance in Principal Component Analysis, but typically the former is much closer to 100 than the latter. So far, no statistical theory of MRFA has been developed. The present paper is a first start. It yields closed-form expressions for the asymptotic bias of the explained common variance, or, more precisely, of the unexplained common variance, under the assumption of multivariate normality. Also, the asymptotic variance of this bias is derived, and also the asymptotic covariance matrix of the unique variances that define a MRFA solution. The presented asymptotic statistical inference is based on a recently developed perturbation theory of semidefinite programming. A numerical example is also offered to demonstrate the accuracy of the expressions.This work was supported, in part, by grant DMS-0073770 from the National Science Foundation.     

Personal epistemology across cultures: exploring Norwegian and Spanish university students’ epistemic beliefs about climate change

The primary aim was to explore and compare the dimensionality of personal epistemology with respect to climate change across the contexts of Norwegian and Spanish students. A second aim was to examine relationships between topic-specific epistemic beliefs and the variables of gender, topic knowledge, and topic interest in the two contexts. Participants were 225 Norwegian and 217 Spanish undergraduates enrolled in psychology or education courses, and the dimensionality of topic-specific personal epistemology was explored through factor analyses of the scores on a 49-item questionnaire. Hierarchical multiple regression analyses were used to predict scores on the epistemic belief dimensions emerging from the factor analyses with gender, topic knowledge, and topic interest, respectively. Even though considerable cross-cultural generalizability in dimensionality was demonstrated, this research also draws attention to the cultural embeddedness of topic-specific epistemic beliefs. Moreover, differences in the predictability of topic knowledge and topic interest in Norway and Spain, suggest that factors constraining or enhancing adaptive epistemic beliefs concerning particular topics may vary across cultures.     

A generalization of Verhelst's solution for a constrained regression problem in alscal and related MDS-algorithms

Verhelst derived a solution for a constrained regression problem which occurs in the interval measurement application of ALSCAL and related MDS-algorithms. In the present paper it is shown that Verhelst's solution is based on an implicit nonsingularity assumption. A general solution, which contains Verhelst's solution as a special case, is derived by a simple completing-the-squares type approach instead of partial differentiation with a Lagrange multiplier. In addition, this approach permits the identification of a small interval which uniquely contains the optimal value of a parameter needed to solve the special case where Verhelst's solution is valid.The author is obliged to Dirk Knol and Klaas Nevels for helpful comments.