Where to place inaccessible subjects in Dutch: The role of definiteness and animacy

Cross-linguistically, both subjects and topical information tend to be placed at the beginning of a sentence. Subjects are generally highly topical, causing both tendencies to converge on the same word order. However, subjects that lack prototypical topic properties may give rise to an incongruence between the preference to start a sentence with the subject and the preference to start a sentence with the most accessible information. We present a corpus study in which we investigate in what syntactic position (preverbal or postverbal) such low-accessible subjects are typically found in Dutch natural language. We examine the effects of both discourse accessibility (definiteness) and inherent accessibility (animacy). Our results show that definiteness and animacy interact in determining subject position in Dutch. Non-referential (bare) subjects are less likely to occur in preverbal position than definite subjects, and this tendency is reinforced when the subject is inanimate. This suggests that these two properties that make the subject less accessible together can ‘gang up’ against the subject first preference. The results support a probabilistic multifactorial account of syntactic variation

Chlamydia control activities in Europe: cross-sectional survey

Background: Chlamydia is the most commonly reported bacterial sexually transmitted infection in Europe. The objective of the Screening for Chlamydia in Europe (SCREen) project was to describe current and planned chlamydia control activities in Europe. Methods: The authors sent a questionnaire asking about different aspects of chlamydia epidemiology and control to public health and clinical experts in each country in 2007. The principles of sexually transmitted infection control were used to develop a typology comprising five categories of chlamydia control activities. Each country was assigned to a category, based on responses to the questionnaire. Results: Experts in 29 of 33 (88%) invited countries responded. Thirteen of 29 countries (45%) had no current chlamydia control activities. Six countries in this group stated that there were plans to introduce chlamydia screening programmes. There were five countries (17%) with case management guidelines only. Three countries (10%) also recommended case finding amongst partners of diagnosed chlamydia cases or people with another sexually transmitted infection. Six countries (21%) further specified groups of asymptomatic people eligible for opportunistic chlamydia testing. Two countries (7%) reported a chlamydia screening programme. There was no consistent association between the per capita gross domestic product of a country and the intensity of chlamydia control activities (P = 0.816). Conclusion: A newly developed classification system allowed the breadth of ongoing national chlamydia control activities to be described and categorized. Chlamydia control strategies should ensure that clinical guidelines to optimize chlamydia diagnosis and case management have been implemented before considering the appropriateness of screening programmes

Chemically defined culture media: rational recipes or witches' brew?

A rational approach to study cells, tissues or even organs is to isolate them from the body and bring them into a controlled, and therefore reproducible, environment. In vivo, cells are surrounded by the extracellular matrix, and the body fluids nourish them. In vitro, these fluids are replaced by culture media. In the early days of tissue culture, tissue was cultured in a drop of clotted lymph. The early-day natural nutrient media have gradually become replaced by media of a more defined composition, culminating in the advent of completely defined culture media.Biomedical Reviews 1996; 6: 111-119

A method for dense packing discovery

The problem of packing a system of particles as densely as possible is foundational in the field of discrete geometry and is a powerful model in the material and biological sciences. As packing problems retreat from the reach of solution by analytic constructions, the importance of an efficient numerical method for conducting \textit{de novo} (from-scratch) searches for dense packings becomes crucial. In this paper, we use the \textit{divide and concur} framework to develop a general search method for the solution of periodic constraint problems, and we apply it to the discovery of dense periodic packings. An important feature of the method is the integration of the unit cell parameters with the other packing variables in the definition of the configuration space. The method we present led to improvements in the densest-known tetrahedron packing which are reported in [arXiv:0910.5226]. Here, we use the method to reproduce the densest known lattice sphere packings and the best known lattice kissing arrangements in up to 14 and 11 dimensions respectively (the first such numerical evidence for their optimality in some of these dimensions). For non-spherical particles, we report a new dense packing of regular four-dimensional simplices with density $\phi=128/219\approx0.5845$ and with a similar structure to the densest known tetrahedron packing.Comment: 15 pages, 5 figure