Traumatic Knee Disorders in General Practice : Diagnosis, course and prognosis

__Abstract__ Musculoskeletal disorders are common, affecting millions of people worldwide and causing short or longterm pain and physical disability, including sick leave. These musculoskeletal disorders represent a substantial burden on the demand for health care systems, resulting in the need for considerable financial budgets. Knee disorders, from both traumatic and non-traumatic origin, make a substantial contribution to the total amount of musculoskeletal disorders

On the origin of intermediate effects in clinical case recall

In two experiments, the effects of level of medical expertise and study time on free recall of a clinical case were assessed. In Experiment 1, a nonmonotonic relationship between level of expertise and recall was found: Subjects of intermediate levels of expertise remembered more information from the case than both experts and novices. This "intermediate effect" disappeared, however, when study time was restricted. Analysis of post hoc acquired protocols of pathophysiological knowledge active during case processing suggested that this phenomenon could be attributed to the nature of the pathophysiological knowledge mobilized to comprehend the case. In Experiment 2, this assumption was directly tested by priming relevant pathophysiological knowledge for either a short or a longer period, before enabling subjects to study the case briefly. Free-recall data confirmed and extended the results of Experiment 1. Again, an intermediate effect was found; this time, however, it was generated experimentally. The findings were interpreted in terms of qualitative differences in the nature of the knowledge structures underlying performance between novices, advanced students, and medical experts: Experts use knowledge in an encapsulated mode while comprehending a case, whereas students use elaborated knowledge

Trends in electro-optical communication systems

This paper gives an overview of present status and future trends in Electro-optical communication systems and networks. Within the architecture of Electro-optical communication networks, three areas with a different type of research focus can be distinguished: the long haul links, the crossconnects and the access networks to the subscribers

3D Acquisition of Mirroring Objects using Striped Patterns

Objects with mirroring optical characteristics are left out of the scope of most 3D scanning methods. We present here a new automatic acquisition approach, shape-from-distortion, that focuses on that category of objects, requires only a still camera and a color monitor, and produces range scans (plus a normal and a reflectance map) of the target. Our technique consists of two steps: first, an improved environment matte is captured for the mirroring object, using the interference of patterns with different frequencies to obtain sub-pixel accuracy. Then, the matte is converted into a normal and a depth map by exploiting the self-coherence of a surface when integrating the normal map along different paths. The results show very high accuracy, capturing even smallest surface details. The acquired depth maps can be further processed using standard techniques to produce a complete 3D mesh of the object

Measuring very negative water potentials with polymer tensiometers: principles, performance and applications

In recent years, a polymer tensiometer (POT) was developed and tested to directly measure matric potentials in dry soils. By extending the measurement range to wilting point (a 20-fold increase compared to conventional, water-filled tensiometers), a myriad of previously unapproachable research questions are now open to experimental exploration. Furthermore, the instrument may well allow the development of more water-efficient irrigation strategies by recording water potential rather than soil water content. The principle of the sensor is to fill it with a polymer solution instead of water, thereby building up osmotic pressure inside the sensor. A high-quality ceramic allows the exchange of water with the soil while retaining the polymer. The ceramic has pores sufficiently small to remain saturated even under very negative matric potentials. Installing the sensor in an unsaturated soil causes the high pressure of the polymer solution to drop as the water potentials in the soil and in the POT equilibrate. As long as the pressure inside the polymer chamber remains sufficiently large to prevent cavitation, the sensor will function properly. If the osmotic potential in the polymer chamber can produce a pressure of approximately 2.0 MPa when the sensor is placed in water, proper readings down to wilting point are secured. Various tests in disturbed soil, including an experiment with root water uptake, demonstrate the operation and performance of the new polymer tensiometer and illustrate how processes such as root water uptake can be studied in more detail than before. The paper discusses the available data and explores the long term perspectives offered by the instrument

Quasi-uniform hyperspaces of compact subsets

AbstractLet (X,u) be a quasi-uniform space, K(X) be the family of all nonempty compact subsets of (X,u). In this paper, the notion of compact symmetry for (X,u) is introduced, and relationships between the Bourbaki quasi-uniformity and the Vietoris topology on K(X) are examined. Furthermore we establish that for a compactly symmetric quasi-uniform space (X,u) the Bourbaki quasi-uniformity u∗ on K(X) is complete if and only if u is complete. This theorem generalizes the well-known Zenor-Morita theorem for uniformisable spaces to the quasi-uniform setting

OFDM MMF optical communication transmission system based on mode group division multiplexing

To increase the transmission capacity of multimode fiber (MMF) drastically, Mode Group Division Multiplexing (MGDM), an optical MIMO technique, can be applied. With MGDM, different mode groups, propagating in MMF are used to carry different information. In this paper, Orthogonal Frequency Division Multiplexing (OFDM), a multi-carrier modulation scheme which not only can make efficient use of the available spectrum but is more resistant to frequency selective fading is proposed in an MGDM system. Simulation results of a 2 x 2 OFDM MGDM system operating at high bitrates will be presented and discussed and an improved performance is shown