Co-variation in time between near-far accommodation of the lens and trapezius muscle activity

Visual strain and discomfort may contribute to the generation of work-related musculoskeletal disorders among e.g. computer workers. A positive correlation on a group level between eye-lens accommodation and trapezius muscle activity has been reported. In this study we investigated the possibility of a direct, fast, connection between lens accommodation and trapezius muscles activity. The subjects focused alternately on Near and Far targets, with a mean switch time of 5 s, through four different lenses. The cross-correlation, R(tau) was computed, between the time signals of accommodation and electromyography (EMG) from 23 subjects. In the overall mean R(tau) of 736 curves, a small but significant correlation peak (0.019) with a delay (of the EMG signal) of about 0.3 s, revealed a small common component in the two signals. Among the lenses, the positive lens (3.5 D), showed the highest correlation peak (0.040). The correlation may be caused by a direct "hard-wired" connection between the ciliary and trapezius muscles. But it could also be caused indirectly by the subject's need for a more stable head in a more demanding visual task. The latter is supported by the result that the correlation was the highest in the positive lens condition. The present correlation is however weak and it has probably a low practical importance.     

Eye- and neck/shoulder-discomfort during visually demanding experimental near work

Frequent use of digital information technology has an impact on eye- and neck/shoulder-discomfort. Studies with cross sectional and intervention design indicate an association between the two symptom categories. Still, whether visually demanding near work, per se, contributes to increased neck/shoulder discomfort remains a question of debate. The aim of this laboratory study was to assess if visually demanding experimental near work affects eye- and neck/shoulder-discomfort when the posture was adjusted for comfort and no movements were allowed. Thirty-three healthy subjects performed a visually demanding computer screen task (viewing task) under four different optical lens conditions: binocular -3.5 D and monocular -3.5 D, +3.5 D and ± 0 D. During the experiment subjects were seated in an office chair (with neck support) that was individually adjusted for comfort. At baseline and after each viewing task, subjects reported their perceived eye- and neck/shoulder discomfort on Borg's CR-10 scale. Results show a significant increase of eye discomfort between baseline and the first viewing task, and a significant increase in neck/shoulder discomfort from baseline throughout the first three viewing tasks. Further analysis is required to determent whether the neck/shoulder discomfort was induced by the demanding near work or the static posture, or a combination.     

Walking in the shoes of others: Experimental testing of dual-interest and empathy in environmental choice

This paper further tests dual interest theory and the metaeconomics approach to environmental choice, recognizing a possible role for empathy–sympathy (the basis for an internalized, shared other-interest) in tempering and conditioning the more fundamental tendency to pursue self-interest. To test, we focus on rivers flowing through agricultural areas carrying sediments, chemicals, and fertilizers which are making their way into downstream rivers and lakes. We conduct a framed laboratory experiment modeling this problem: farmers decide on the usage of conservation technology to lessen impacts on the water quality (i.e. on the commons, the capacity to absorb these wastes) in downstream areas, which is more costly than the alternative intensive technology. The results confirm our hypotheses, demonstrating that Upstream Farmers who practice conservation are tempering profit maximization with empathy-based, environmentally conscious behavior. Such behavior better serves the farmers’ own-interest, and also helps Downstream Water Users. Environmental economics models need to explicitly include empathy–sympathy and the moral–ethical context it produces, providing a more scientific basis for conservation policy and programs.     

Market hours,household work,child care,and wage rates of partners: an empirical analysis

The aim of this paper is to provide new evidence on the effect of partners’ wages on partners’ allocation of time. Earlier studies concluded that wage rates are an important determinant of partners’ hours of market and non-market work and also that house work may lower married women’s wage rates. However, the bulk of earlier literature in this area failed to account for the endogeneity of wages or the simultaneity of partners’ time allocation choices. Here we take a reduced form approach and specify a ten simultaneous equations model of wage rates, employment and hours of market work, house work and childcare of parents. Non-participants are included in the model. We exploit a rich time use dataset for France to estimate the model. We find that the own wage affects positively own market hours and negatively own house work and childcare hours. The wage of the father has a significantly negative effect on the mother’s market hours while her wage rate has a significantly positive effect on his house work hours.     

A vector of quarters representation for bivariate time series

In this paper it is shown that several models for a bivariate nonstationary quarterly time series are nested in a vector autoregression with cointegration restrictions for the eight annual series of quarterly observations. Or, the Granger Representation Theorem is extended to incorporate, e.g., seasonal and periodic cointegration.     

Consistent Probabilistic Social Choice

Two fundamental axioms in social choice theory are consistency with respect to a variable electorate and consistency with respect to components of similar alternatives. In the context of traditional non‐probabilistic social choice, these axioms are incompatible with each other. We show that in the context of probabilistic social choice, these axioms uniquely characterize a function proposed by Fishburn (1984). Fishburn's function returns so‐called maximal lotteries, that is, lotteries that correspond to optimal mixed strategies in the symmetric zero‐sum game induced by the pairwise majority margins. Maximal lotteries are guaranteed to exist due to von Neumann's Minimax Theorem, are almost always unique, and can be efficiently computed using linear programming.     

Suicide ideation,anxiety, and depression: Are children a protective factor for male Veterans?

ABSTRACT

Numerous mental health disorders plague our veterans when they return from deployment including anxiety and depressive disorders, which have been linked to elevated suicide risk when left untreated. Family factors, such as parenthood status, may serve as a protective factor against these mental health issues. This study examined the role of parenthood status of male veterans (N = 234) based on age of the child in order to determine whether a child’s age (minor children v. adult children) affects the likelihood of meeting diagnosis criteria for anxiety, depression, and suicide ideation after controlling for marital status. Three hierarchical binary logistic regression models were constructed to assess the predictive influence of children 18 years old and younger, children older than 18, and no children with the results indicating that parenthood status did meaningfully enhance the prediction of suicide ideation. Complete findings, clinical implications, and future considerations are discussed.     

How Rules Matter: Electoral Reform in Taiwan*

Objectives. This article is a test of general electoral theory in the case of Taiwan's 2008, postreform legislative election. In light of Taiwan's electoral reform, I test several hypotheses related to choice in electoral design and winning conditions, effective number of parties, proportionality, and regionalism. Methods. I run a simulation of the new rules and districting using the previous (2004) election results and compare this to the actual results. By comparing simulated and actual outcomes, I can compare theoretically‐driven, a priori expectations with election outcomes. Results. Primary findings are that a dominant seat share for the Nationalist Party, decline in third‐party representation, and disproportionality were largely predicated on the transition to a majoritarian system. Conclusion. General electoral theory holds robust predictive power in the case of Taiwan.     

How People Perceive and Will Cope with Risks from the Diffusion of Ubiquitous Information and Communication Technologies

Information and communication technologies (ICTs) are increasingly pervasive and continue to reshape our environment. This trend carries different risks. Therefore, the early sensitization of people to these risks, as well as improving their capacity for protective coping behavior, is essential. Based on the protection motivation theory (PMT), we examined with structural equation modeling the relationships between different components of threat and coping appraisal to explain protective and nonprotective responses. Calculations were performed with data from a representative survey on perception and use of ICT among German residents (N= 5,030). Our findings largely supported the proposed model: an increased perceived threat was positively related to the intentions to react protectively and nonprotectively. Perceived coping efficacy increased the protective and decreased the nonprotective responses. Negative affect enhanced the perceived threat and the nonprotective response, but inhibited protective intentions. The implications of these findings on how to sensitize people to the risks of these new technologies are outlined.