Detection of four species of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected from roe deer (Capreolus capreolus) in The Netherlands

Epiglottic disruption is an uncommon injury usually associated with significant supraglottic trauma. This injury may be overlooked because of the difficulty in examining the larynx or other associated severe injuries. We present two cases of clinically unsuspected epiglottic disruption that were first seen on MR images of the neck.     

Soccer schedules in Europe: an overview

In this paper, we give an overview of the competition formats and the schedules used in 25 European soccer competitions for the season 2008?C2009. We discuss how competitions decide the league champion, qualification for European tournaments, and relegation. Following Griggs and Rosa (Bull. ICA 18:65?C68, 1996), we examine the popularity of the so-called canonical schedule. We investigate the presence of a number of properties related to successive home or successive away matches (breaks) and of symmetry between the various parts of the competition. We introduce the concept of ranking-balancedness, which is particularly useful to decide whether a fair ranking can be made. We also determine how the schedules manage the carry-over effect. We conclude by observing that there is quite some diversity in European soccer schedules, and that current schedules leave room for further optimizing.     

Overactuation: A solution for the accuracy-throughput speed contradiction in parallel axis positioning systems

In parallel axis positioning systems an accuracy-throughput speed contradiction is present. The configuration is often such that the minimum number of actuators from kinematic point of view is used. The mechanical system should possess sufficient stiffness but also low mass. Structural stiffness, and hence accuracy, is obtained at the cost of mass. In intermittent motion systems the moving mass should be minimized, because it limits the attainable acceleration and thus the throughput speed. This dynamic performance barrier can be shifted with additional parallel actuators. To enhance prudence in the initial design phase, knowledge about the opportunities and limitations of parallel axis systems is required. The basic dynamical aspects of parallel axis positioning systems, with a minimum and additional number of parallel actuators, are examined for beam and plate systems. The results of the numerical models are verified with an experimental plate system.     

All normalized anti-monotonic overlap graph measures are bounded

In graph mining, a frequency measure for graphs is anti-monotonic if the frequency of a pattern never exceeds the frequency of a subpattern. The efficiency and correctness of most graph pattern miners relies critically on this property. We study the case where frequent subgraphs have to be found in one graph. Vanetik et al. (Data Min Knowl Disc 13(2):243?C260, 2006) already gave sufficient and necessary conditions for anti-monotonicity of graph measures depending only on the edge-overlaps between the instances of the pattern in a labeled graph. We extend these results to homomorphisms, isomorphisms and homeomorphisms on both labeled and unlabeled, directed and undirected graphs, for vertex- and edge-overlap. We show a set of reductions between the different morphisms that preserve overlap. As a secondary contribution, we prove that the popular maximum independent set measure assigns the minimal possible normalized frequency and we introduce a new measure based on the minimum clique partition that assigns the maximum possible normalized frequency. In that way, we obtain that all normalized anti-monotonic overlap graph measures are bounded from above and below. We also introduce a new measure sandwiched between the former two based on the polynomial time computable Lovász ??-function.     

Managing value-at-risk for a bond using bond put options

This paper studies a strategy that minimizes the Value-at-Risk (VaR) of a position in a zero-coupon bond by buying a percentage of a put option, subject to a fixed budget available for hedging. We elaborate a formula for determining the optimal strike price for this put option in case of a Vasicek stochastic interest rate model. We demonstrate the relevance of searching the optimal strike price, since moving away from the optimum implies a loss, either due to an increased VaR or due to an increased hedging expenditure. In this way, we extend the results of [Ahn, Boudoukh, Richardson, and Whitelaw (1999). Journal of Finance, 54, 359–375] who minimize VaR for a position in a share. In addition, we look at the alternative risk measure Tail Value-at-Risk.     

Design of a kinematic coupling for precision applications

To machine a complex precision product, several tools are needed. These tools are placed on a tool turret. A tool must return several times to its original position. To attain a very high repeatability between the upper part and the base of the tool turret mounted on a precision lathe, it is preferable that the parts of the tool turret are statically determined in their contacts. This is attained by using a kinematic coupling. To attain the required stiffness this coupling is provided with a preload of 1.5 · 10³ N. The machining forces are typically less than 1 Newton. A special kinematic coupling, consisting of grooves and balls, was designed, made, and tested. By providing the grooves with self-adjusting surfaces, hysteresis is reduced to less than one-tenth of a micrometer. Maximum stiffness is aimed at by using cemented carbide, a material with a high admissible stress, at the contact points. Experiments show that this kinematic coupling, under a preload of 1.5 · 10³ N, has a static stiffness of more than 1 · 10⁸ N/m in every direction and a repeatability better than one-tenth of a micrometer.     

Microbial nitrogen dynamics in south central Chilean agricultural and forest ecosystems located on an Andisol

The natural soil N supply in volcanic soils (Andisols) can be a significant source of plant-available N for agro-ecosystems. Nevertheless, intensive farming systems in south Chile apply high fertilization rates, which lead to high production costs and involve a risk for adverse ecosystem effects. In order to achieve sustainable land management, a better understanding of the processes that govern soil N availability and loss, and their external drivers, is required. In this study, we selected a winter-cropland, a summer crop-winter fallow rotation, and a forest, used as a reference ecosystem. Gross N transformations (¹⁵N isotope dilution) and microbial community structure (phospho-lipid fatty acid analysis) in the topsoil were determined. Gross N mineralization was about ten times lower in the agro-ecosystems than in the forest, while gross nitrification was low in all sites. Gross N immobilization equalized or exceeded the gross inorganic N production in all sites. Microbial biomass was 3–5 times more abundant in the forest than in the agro-ecosystems. A positive relationship between the ratio fungi/bacteria and total microbial biomass was observed in these Andisols. We suggest that the reduction in fungal biomass induced a lower extracellular enzyme production and limited soil organic matter depolymerisation in the agro-ecosystems. We conclude that soil N cycling was unable to provide a significant N input for the croplands, but also the risk for ecosystem N losses was low, even under fallow soil conditions. Current fertilization practices appropriately anticipated the soil N cycling processes, but further research should indicate the potential of alternative land management to reduce fertilizer cost.