Seroprevalence of bluetongue serotype 8 in cattle in the Netherlands in spring 2007, and its consequences

A cross-sectional study was carried out in spring 2007, at the end of the first bluetongue outbreak season, to determine the geographical spread of bluetongue virus serotype 8 (BTV-8) infection in cattle in the Netherlands and the consequences for some production parameters. Blood samples from cattle submitted to the laboratory of the Dutch Animal Health Service for other voluntary and obligatory health programmes were tested serologically for BTV-8. in total, 37,073 samples were tested and 659 (1.78 per cent) were seropositive. The samples came from 5436 herds, of which 45 per cent of herds had only one sample submitted from them. The prevalence was highest in the south of the country, where the outbreak had started, and decreased towards the north. in 340 herds more than 50 per cent of cattle were tested, of which 156 herds were located in infected compartments, and in 37 of these herds (10.9 per cent) at least one positive cow was detected. The average within-herd prevalence in the 37 herds was 39.3 per cent: 2.2 per cent in I I dairy herds, 68.4 per cent in 20 small-scale herds and 14 per cent in four suckler cow herds. The prevalence differed significantly between herd types but did not show a geographical trend. The average net return for milk production amounted to is an element of 2417/cow/year and it decreased significantly on average by is an element of 48/ cow/year in the bluetongue-infected dairy herds during the bluetongue period. on the small-scale farms, the incidence of mortality increased by 3.2 (95 per cent confidence interval [a] 1.2 to 9.1) times in the infected herds during the bluetongue period, but the voluntary culling rate decreased by a factor of 2.3 (95 per cent Cl 1.1 to 4.8)

Axial Flow over a Blunt Circular Cylinder with and without Shear Layer Reattachment

Flow over a circular cylinder with its axis aligned with the free stream was investigated experimentally. Both upstream and downstream faces of the cylinder are sharply truncated. The fineness ratio (length to diameter ratio) was varied and the behavior of the leading-edge separating shear layer and its effect on the wake were studied in water using both flow visualization and PIV techniques. For the moderately large fineness ratio, the shear layer reattaches with subsequent boundary layer growth, whereas over a shorter cylinder the shear layer remains detached. This causes differences in the wake recirculation region and the immediate wake patterns. The shear layer structure was analyzed using the proper orthogonal decomposition (POD). The model in the water channel was sting-mounted and in some cases the effect of model support was detected in the wake measurements. To avoid such disturbance from the model support, an experiment was initiated in air using a magnetic model support and balance system. The drag variation with fineness ratio is presented and discussed in light of the flowfield measurements

The Thermopower of Quantum Chaos

The thermovoltage of a chaotic quantum dot is measured using a current heating technique. The fluctuations in the thermopower as a function of magnetic field and dot shape display a non-Gaussian distribution, in agreement with simulations using Random Matrix Theory. We observe no contributions from weak localization or short trajectories in the thermopower.Comment: 4 pages, 3 figures, corrected: accidently omitted author in the Authors list, here (not in the article

From planning the port/city to planning the port-city : exploring the economic interface in European port cities

In last three decades, planning agencies of most ports have institutionally evolved into a (semi-) independent port authority. The rationale behind this process is that port authorities are able to react more quickly to changing logistical and spatial preferences of maritime firms, hence increasing the competitiveness of ports. Although these dedicated port authorities have proven to be largely successful, new economic, social, and environmental challenges are quickly catching up on these port governance models, and particularly leads to (spatial) policy ‘conflicts’ between port and city. This chapter starts by assessing this conflict and argue that the conflict is partly a result of dominant—often also academic—spatial representations of the port city as two separate entities. To escape this divisive conception of contemporary port cities, this chapter presents a relational visualisation method that is able to analyse the economic interface between port and city. Based on our results, we reflect back on our proposition and argue that the core challenge today for researchers and policy makers is acknowledging the bias of port/city, being arguably a self-fulfilling prophecy. Hence, we turn the idea of (planning the) port/city conflicts into planning the port-city’s strengths and weaknesses

Conditions for Adiabatic Spin Transport in Disordered Systems

We address the controversy concerning the necessary conditions for the observation of Berry phases in disordered mesoscopic conductors. For this purpose we calculate the spin-dependent conductance of disordered two-dimensional structures in the presence of inhomogeneous magnetic fields. Our numerical results show that for both, the overall conductance and quantum corrections, the relevant parameter defining adiabatic spin transport scales with the square root of the number of scattering events, in generalization of Stern's original proposal [Phys. Rev. Lett. 68, 1022 (1992)]. This could hinder a clear-cut experimental observation of Berry phase effects in diffusive metallic rings.Comment: 5 pages, 4 figures. To appear in Phys. Rev. B (Rapid Communications

Views of patients and parents of children with genetic disorders on population-based expanded carrier screening

Objective Faster and cheaper next generation sequencing technologies have enabled expansion of carrier screening for recessive disorders, potentially facilitating population-based implementation regardless of ancestry or family history. Little is known, however, about the attitudes regarding population-based carrier screening among families with genetic disorders. This study assessed views among parents and patients with a recessive disorder and parents of children with Down syndrome (DS) on expanded carrier screening (ECS). Method In total, 85 patients with various recessive disorders, 110 parents of a child with a recessive disorder and 89 parents of a child with DS participated in an online survey in the Netherlands. Severity of recessive disorders was classified as mild/moderate or severe/profound. Results The majority of the (parents of) patients with a recessive disorder had a positive attitude towards population-based ECS, including screening for their own or their child's disorder. DS parents were significantly less positive towards ECS. Subgroup analyses showed that the severity of the disorder, rather than being a patient or parent, influences the attitudes, beliefs and intention to participate in ECS. Conclusion Our findings have important implications for future implementation initiatives as they demonstrate the different perspectives from people with experiential knowledge with genetic disorders

Wavefunction statistics in open chaotic billiards

We study the statistical properties of wavefunctions in a chaotic billiard that is opened up to the outside world. Upon increasing the openings, the billiard wavefunctions cross over from real to complex. Each wavefunction is characterized by a phase rigidity, which is itself a fluctuating quantity. We calculate the probability distribution of the phase rigidity and discuss how phase rigidity fluctuations cause long-range correlations of intensity and current density. We also find that phase rigidities for wavefunctions with different incoming wave boundary conditions are statistically correlated.Comment: 4 pages, RevTeX; 1 figur