Utrecht University

About: Utrecht University is a education organization based out in Utrecht, Utrecht, Netherlands. It is known for research contribution in the topics: Population & Poison control. The organization has 58176 authors who have published 139351 publications receiving 6214282 citations. The organization is also known as: UU & Universiteit Utrecht.

Crafting a job on a daily basis: Contextual correlates and the link to work engagement

Abstract: Summary This study focused on daily job crafting and explored its contextual determinants and one motivational outcome (ie, work engagement) Job crafting was conceptualized as “seeking resources, ”“ seeking challenges,” and “reducing demands” Participants were 95 employees from several organizations who completed a 5-day diary survey As hypothesized, we found a 3-factor structure for the job crafting instrument, both at the general and day levels We hypothesized and found that the combination of high day-level work pressure and high day-level autonomy (active jobs) was associated with higher day-level seeking resources and lower day-level reducing demands Furthermore, we found that day-level seeking challenges (but not resources) was positively associated with day-level work engagement, whereas day-level reducing demands was negatively associated with day-level work engagement Findings suggest that job crafting is a daily employee behavior with implications for management practice and future research Copyright © 2012 John Wiley & Sons, Ltd

Lipoprotein particles are required for Hedgehog and Wingless signalling

Abstract: Wnt and Hedgehog family proteins are secreted signalling molecules (morphogens) that act at both long and short range to control growth and patterning during development. Both proteins are covalently modified by lipid, and the mechanism by which such hydrophobic molecules might spread over long distances is unknown. Here we show that Wingless, Hedgehog and glycophosphatidylinositol-linked proteins copurify with lipoprotein particles, and co-localize with them in the developing wing epithelium of Drosophila. In larvae with reduced lipoprotein levels, Hedgehog accumulates near its site of production, and fails to signal over its normal range. Similarly, the range of Wingless signalling is narrowed. We propose a novel function for lipoprotein particles, in which they act as vehicles for the movement of lipid-linked morphogens and glycophosphatidylinositol-linked proteins.

Image registration by maximization of combined mutual information and gradient information

Abstract: Mutual information has developed into an accurate measure for rigid and affine monomodality and multimodality image registration. The robustness of the measure is questionable, however. A possible reason for this is the absence of spatial information in the measure. The present paper proposes to include spatial information by combining mutual information with a term based on the image gradient of the images to be registered. The gradient term not only seeks to align locations of high gradient magnitude, but also aims for a similar orientation of the gradients at these locations. Results of combining both standard mutual information as well as a normalized measure are presented for rigid registration of three-dimensional clinical images [magnetic resonance (MR), computed tomography (CT), and positron emission tomography (PET)]. The results indicate that the combined measures yield a better registration function does mutual information or normalized mutual information per se. The registration functions are less sensitive to low sampling resolution, do not contain incorrect global maxima that are sometimes found in the mutual information function, and interpolation-induced local minima can be reduced. These characteristics yield the promise of more robust registration measures. The accuracy of the combined measures is similar to that of mutual information-based methods.

Evolution of microRNA diversity and regulation in animals

Abstract: In the past decade, microRNAs (miRNAs) have been uncovered as key regulators of gene expression at the post-transcriptional level. The ancient origin of miRNAs, their dramatic expansion in bilaterian animals and their function in providing robustness to transcriptional programmes suggest that miRNAs are instrumental in the evolution of organismal complexity. Advances in understanding miRNA biology, combined with the increasing availability of diverse sequenced genomes, have begun to reveal the molecular mechanisms that underlie the evolution of miRNAs and their targets. Insights are also emerging into how the evolution of miRNA-containing regulatory networks has contributed to organismal complexity.