University of Antwerp

About: University of Antwerp is a education organization based out in Antwerp, Belgium. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 16682 authors who have published 48837 publications receiving 1689748 citations. The organization is also known as: Universiteit Antwerpen & UAntwerp.

Sexual dimorphism of head size in Gallotia galloti: testing the niche divergence hypothesis by functional analyses

Abstract: 1. Two often cited hypotheses explaining sexual head size dimorphism in lizards are: sexual selection acting on structures important in intrasexual competition, and reduction of intersexual competition through food niche separation. 2. In this study some implicit assumptions of the latter hypothesis were tested, namely that an increase in gape distance and bite force should accompany the observed increase in head size. These assumptions are tested by recording bite forces, in vivo, for lizards of the species Gallotia galloti. In this species, male lizards have significantly larger heads than female conspecifics of similar snout–vent length. 3. Additionally, the average force needed to crush several potential prey species was determined experimentally and compared with the bite force data. This comparison clearly illustrates that animals of both sexes can bite much harder than required for most insect food items, which does not support the niche divergence hypothesis. The apparent ‘excess’ bite force in both sexes might be related to the partially herbivorous diet of the animals. 4. To unravel the origin of differences between sexes in bite capacity, the crushing phase of biting was modelled. The results of this model show different strategies in allocation of muscle tissue between both sexes. The origin of this difference is discussed and a possible evolutionary pathway of the development of the sexual dimorphism in the species is provided.

Life cycle assessment in the construction sector: A review

Abstract: The last decades, lowering the ecological impact of buildings is receiving increased attention by researchers, policy-makers and companies. Mostly the focus is on reducing energy consumption and the use of eco-friendly materials, but the concept of life-cycle thinking is growing in importance. This paper tries to give an overview of the current situation of Life cycle assessment (LCA) in the construction industry, both of regulatory developments and academic case studies. After a short history of LCA, the focus is on LCA methodology, new standards and frameworks and an extensive selection of recent case studies. Despite some inherent limitations of LCA as an analytic tool and fundamental differences between the individual cases, still some common trends can be indicated. In standard buildings, the use phase contributes up to 90% of the total environmental burdens, mainly due to heating and/or cooling. Due to regulations, new buildings become more energy efficient, and thereby other phases of the life cycle gain in importance e.g., choice of materials, construction, end-of-life and water use. These research topics deserve more attention, together with economic issues, the improvement of data quality and implementation of probability density distributions.

Representing text chunks

Abstract: Dividing sentences in chunks of words is a useful preprocessing step for parsing, information extraction and information retrieval. (Ramshaw and Marcus, 1995) have introduced a "convenient" data representation for chunking by converting it to a tagging task. In this paper we will examine seven different data representations for the problem of recognizing noun phrase chunks. We will show that the the data representation choice has a minor influence on chunking performance. However, equipped with the most suitable data representation, our memory-based learning chunker was able to improve the best published chunking results for a standard data set.

Emerging model systems in plant biology: poplar (Populus) as a model forest tree.

Abstract: Forest trees have tremendous economic and ecological value, as well as unique biological properties of basic scientific interest. The inherent difficulties of experimenting on very large long-lived organisms motivates the development of a model system for forest trees. Populus (poplars, cottonwoods, aspens) has several advantages as a model system, including rapid growth, prolific sexual reproduction, ease of cloning, small genome, facile transgenesis, and tight coupling between physiological traits and biomass productivity. A combination of genetics and physiology is being used to understand the detailed mechanisms of forest tree growth and development.