Form Perception of Partly Occluded Shapes in 4‐Month‐Old Infants

Two habituation experiments were conducted to investigate how 4‐month‐old infants perceive partly occluded shapes. In the first experiment, we presented a simple, partly occluded shape to the infants until habituation was reached. Then we showed either a probable completion (one that would be predicted on the basis of both local and global cues) or an improbable completion. Longer looking times were found for the improbably completed shape (compared to probable and control conditions), suggesting that the probable shape was perceived during partial occlusion. In the second experiment, infants were habituated to more ambiguous partly occluded shapes, where local and global cues would result in different completions. For adults, the percept of these shapes is usually dominated by global influences. However, after habituation the infants looked longer at the globally completed shapes. These results suggest that by the age of 4 months, infants are able to infer the perceptual completion of partly occluded shapes, but for more ambiguous shapes, this completion seems to be dominated by local influences.     

“Post-Gay” Yet? The Relevance of the Lesbian and Gay Scene to Same-Sex Attracted Young People in Contemporary Australia

In recent years, the lesbian and gay “scene” of bars, nightclubs, and dance parties has been undergoing a structural decline in many Western cities. This article aimed to examine the relevance of the scene to same-sex attracted young adults amid these changes. An online survey was conducted with 572 same-sex attracted young women and men in Sydney. Only a minority of respondents participated in the scene at least weekly (16%), and the majority did not regard the scene as important to their leisure time (60%). However, respondents valued the scene as a space to connect with other same-sex attracted people and display same-sex affection without fear of hostility. Lesbian and gay identified respondents tended to be more socially engaged with the scene compared to other same-sex attracted respondents. The findings suggest that while the scene continues to be valued by many same-sex attracted young people, improved social attitudes have made participating in the scene less of an imperative.     

A psychometric evaluation of a Dutch version of the Job Content Questionnaire and of a short direct questioning procedure

Using the demand-control-support perspective on job stress, a Dutch translation of an adapted version of the Job Content Questionnaire (AJCQ) was administered to a large population ( N = 3638) of Flemish workers in a variety of jobs, together with the General Health Questionnaire, and a negative affectivity scale. Overall, the AJCQ was shown to be a solid measurement instrument as indicated by several estimated reliability indices and validity of the subscales. A factor analysis largely reproduced the a priori structure of the AJCQ. A short 10-item direct questioning procedure was constructed to measure the 10 subscales of the AJCQ and the results of this procedure were compared with the AJCQ in a subsample ( N = 660). The correlations with six criterion variables showed that single questions were equally predictive than the much longer version of the AJCQ.     

Cost-Utility Analysis to Control Campylobacter on Chicken Meat—Dealing with Data Limitations

The current article describes the economic evaluation of interventions to control Campylobacter on chicken meat by means of a cost-utility analysis. Apart from the methodology used, the main focus of this article is on data gaps and assumptions made, and their impact on results and conclusions. The direct intervention costs, the relative risk, the disease burden (expressed in disability-adjusted life years (DALYs)), and the costs of illness for the various interventions are necessary inputs for the cost-utility analysis. The cost-utility ratio (CUR) -- the measure for efficiency -- is expressed in net costs per avoided DALY. Most data gaps were of a biological order, but for some interventions, information on costs was also scarce. As a consequence, assumptions had to be made, which had some impact on the estimated CUR. A higher (lower) incidence of Campylobacter infections associated with chicken meat, higher (lower) effectiveness, and lower (higher) intervention costs, respectively, would result in absolute better (worse) CUR estimates. By taking the perspective of all consumers eating Dutch chicken meat, rather than only the Dutch society, absolute better CUR estimates could be obtained. Indirect costs or a shift toward non-Dutch chicken meat would both result in higher CUR estimates. Despite the assumptions made, three interventions showed for most of the applied sensitivity analyses relatively favorable CUR estimates: limiting fecal leakage during processing, carcass decontamination by dipping in a chemical solution, and the phage therapy. However, all three do have some clauses.     

Volunteering and Wellbeing Among Ageing Adults: A Longitudinal Analysis

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Previous scholarship has shown evidence of a positive relationship between volunteering and improved measures of mental...     

Effectiveness and Efficiency of Controlling Campylobacter on Broiler Chicken Meat

Campylobacter bacteria are an important cause of foodborne infections. We estimated the potential costs and benefits of a large number of possible interventions to decrease human exposure to Campylobacter by consumption of chicken meat, which accounts for 20-40% of all cases of human campylobacteriosis in the Netherlands. For this purpose, a farm-to-fork risk assessment model was combined with economic analysis and epidemiological data. Reduction of contamination at broiler farms could be efficient in theory. However, it is unclear which hygienic measures need to be taken and the costs can be very high. The experimental treatment of colonized broiler flocks with bacteriophages has proven to be effective and could also be cost efficient, if confirmed in practice. Since a major decrease of infections at the broiler farm is not expected in the short term, additional measures in the processing plant were also considered. At this moment, guaranteed Campylobacter-free chicken meat at the retail level is not realistic. The most promising interventions in the processing plant are limiting fecal leakage during processing and separation of contaminated and noncontaminated flocks (scheduling), followed by decontamination of the contaminated flock. New (faster and more sensitive) test methods to detect Campylobacter colonization in broilers flocks are a prerequisite for successful scheduling scenarios. Other methods to decrease the contamination of meat of colonized flocks such as freezing and heat treatment are more expensive and/or less effective than chemical decontamination.     

An equivalence test for comparing DNA sequences

The practice of sequence alignment is constantly oscillating between the risk of overlooking important structure and that of discovering any arbitrarily defined kind of structure anywhere. On the other hand, the use of a condensed consensus sequence may lead to a substantial loss in valuable information. While adopting a Mahalanobis‐type index we allow for a certain degree of uncertainty in the measurements. This uncertainty may be caused by inaccurate measurements or ambiguity. In this paper, we test the similarity between DNA sequences within the framework of equivalence testing, accounting for both variances and covariances between frequencies of nucleotides. Statistical methods for testing equivalence were first developed in the context of pharmacokinetics and later extended to the field of clinical trials. Nowadays, (bio)equivalence tests seem to be less frequently used outside the drug testing field, including statistical genetics. Copyright © 2005 John Wiley & Sons, Ltd.