Metric Semantics and Full Abstractness for Action Refinement and Probabilistic Choice

This paper provides a case-study in the field of metric semantics for probabilistic programming. Both an operational and a denotational semantics are presented for an abstract process language L_pr, which features action refinement and probabilistic choice. The two models are constructed in the setting of complete ultrametric spaces, here based on probability measures of compact support over sequences of actions. It is shown that the standard toolkit for metric semantics works well in the probabilistic context of L_pr, e.g. in establishing the correctness of the denotational semantics with respect to the operational one. In addition, it is shown how the method of proving full abstraction --as proposed recently by the authors for a nondeterministic language with action refinement-- can be adapted to deal with the probabilistic language L_pr as well

Hoge benutting meststoffen voorwaarde voor goed resultaat : 50% minder kunstmest in drie jaar

In drie jaar Koeien & Kansen is het kunstmestgebruik op de bedrijven met bijna 50 procent gedaald. Gelijktijdig verbeterde de benutting van de stikstof uit de dierlijke mest en kunstmest. De bijdrage van klaver biedt daarbij extra mogelijkheden. Ook het gebruik van fosfaatkunstmest is in dezelfde periode met meer dan de helft afgenomen

Voorjaarsmeststoffen: meer gras met minder stikstof

Om aan de verliesnormen voor 2003 te voldoen zal de stikstofjaargift op veel bedrijven lager zijn dan het landbouwkundig advies. Daarom is het dringend gewenst de stikstof maximaal te benutten. Eén van de mogelijkheden is het gebruik van voorjaarsmeststoffen. Enkele Koeien & Kansen deelnemers behaalden hiermee sprekende resultaten

Neurogenic tumours of the posterior mediastinum and differential diagnosis considerations

The mediastinal compartment harbours vital organs and structures, including the heart, great vessels, major airways, and thymus. These structures are embedded in and associated with soft-tissue elements consisting of adipose and fibro-collagenous tissue in which soft-tissue tumours may develop. A detailed inventory of soft-tissue tumours that may be encountered in the mediastinum based on the WHO 2013 classification was published in 2015. In addition, several comprehensive reviews on mediastinal soft-tissue pathology are available, including reviews focusing specifically on a single tumour type. This review will focus on primary neurogenic and spindle cell tumours of the somatic soft tissue of the posterior mediastinum and provide a discussion of the pertinent differential diagnoses

Lineage specific recombination rates and microevolution in Listeria monocytogenes

Background: The bacterium Listeria monocytogenes is a saprotroph as well as an opportunistic human foodborne pathogen, which has previously been shown to consist of at least two widespread lineages (termed lineages I and II) and an uncommon lineage (lineage III). While some L. monocytogenes strains show evidence for considerable diversification by homologous recombination, our understanding of the contribution of recombination to L. monocytogenes evolution is still limited. We therefore used STRUCTURE and ClonalFrame, two programs that model the effect of recombination, to make inferences about the population structure and different aspects of the recombination process in L. monocytogenes. Analyses were performed using sequences for seven loci (including the house-keeping genes gap, prs, purM and ribC, the stress response gene sigB, and the virulence genes actA and inlA) for 195 L. monocytogenes isolates. Results: Sequence analyses with ClonalFrame and the Sawyer's test showed that recombination is more prevalent in lineage II than lineage I and is most frequent in two house-keeping genes (ribC and purM) and the two virulence genes (actA and inlA). The relative occurrence of recombination versus point mutation is about six times higher in lineage II than in lineage I, which causes a higher genetic variability in lineage II. Unlike lineage I, lineage II represents a genetically heterogeneous population with a relatively high proportion (30% average) of genetic material imported from external sources. Phylograms, constructed with correcting for recombination, as well as Tajima's D data suggest that both lineages I and II have suffered a population bottleneck. Conclusion: Our study shows that evolutionary lineages within a single bacterial species can differ considerably in the relative contributions of recombination to genetic diversification. Accounting for recombination in phylogenetic studies is critical, and new evolutionary models that account for the possibility of changes in the rate of recombination would be required. While previous studies suggested that only L. monocytogenes lineage I has experienced a recent bottleneck, our analyses clearly show that lineage II experienced a bottleneck at about the same time, which was subsequently obscured by abundant homologous recombination after the lineage II bottleneck. While lineage I and lineage II should be considered separate species from an evolutionary viewpoint, maintaining single species name may be warranted since both lineages cause the same type of human disease

Detection and aerosol treatment of small airway disease in pediatric cystic fibrosis and asthma

Respiratory disease is frequently present in childhood. It can be divided into upper airway disease and lower airway or lung disease. Two important lung diseases in childhood are cystic fibrosis (CF) and asthma. They are important because CF is the most common lethal genetic disease in the Caucasian population and asthma is one of the most frequent chronic diseases of childhood, with a prevalence of approximately 10% of children in the West

Financieel-economische aspecten van Biobrandstofproductie : deskstopstudie naar de invloed van co-productie van bio-based producten op de financiële haalbaarheid van biobrandstoffen

Door uitvoering van een deskstop studie heeft WUR, in samenwerking met ECN, onderzocht of co-productie van biobrandstoffen en bio-based producten leidt tot meer marktcompetitieve biobrandstofproductie. De centrale vraagstelling van de studie was of aangetoond kan worden dat “co-productie” resulteert in realisatie van meer marktcompetitieve waardeketens voor grootschalige en duurzame inzet van biomassa in de biobased economy. De studie naar de financiële haalbaarheid van een twaalftal biobrandstofketens laten zien dat co-productie van biobrandstoffen tezamen met bio-based producten een goede methode is om additionele waarde toe te kennen aan de totale biomassa-product-keten. De co-producten die tezamen met biobrandstoffen geproduceerd kunnen worden zijn zeer divers. In het algemeen bestaat er voor deze co-producten een omvangrijke afzetmarkt, en gaat het om producten die op dit moment grotendeels uit aardolie vervaardigd worden. Technologieën voor productie en toepassing van hoogwaardige co-producten die naast biobrandstoffen uit biomassa geproduceerd kunnen worden bevinden zich in verschillende stadia van ontwikkeling

Exploring interactive systems using peripheral sounds

Our everyday interaction in and with the physical world, has facilitated the development of auditory perception skills that enable us to selectively place one auditory channel in the center of our attention and simultaneously monitor others in the periphery. We search for ways to leverage these auditory perception skills in interactive systems. In this paper, we present three working demonstrators that use sound to subtly convey information to users in an open office. To qualitatively evaluate these demonstrators, each of them has been implemented in an office for three weeks. We have seen that such a period of time, sounds can start shifting from the center to the periphery of the attention. Furthermore, we found several issues to be addressed when designing such systems, which can inform future work in this area.</p