4,687 research outputs found
An extendable modular endoprosthetic system for bone tumour management in the leg
A modular endoprosthetic system has been developed at the Groningen University Hospital and the University of Twente. The system can bridge a defect resulting from the resection of a malignant bone tumour which has developed around the knee joint of a child. Since the other healthy leg continues to grow, the system includes an element whose length can be adjusted non-invasively by using an external magnetic field. In addition to this lengthening element, there are one hip and two knee components, connectors of various lengths, and fixation elements. The paper describes the elements of the modular endoprosthetic system. Tables are created by means of which the elemental composition of such an endoprosthesis can be determined for each individual patient
Legal Ignorance and Information-Forcing Rules
People are often ignorant about the legal rules that govern the most common transactions in their lives. This Article analyzes one common regulatory response to our widespread legal ignorance. A surprisingly broad range of legal rules have the ostensible purpose of inducing sophisticated parties to draft express contract language that will inform their contractual partners about the legal rules governing a particular transaction. However, this “legal-informationforcing” objective often remains unrealized because people routinely sign contracts without reading and understanding their terms. In theory, courts could design information-forcing rules that would be truly informative. But recognizing the potential futility of attempts to inform many contracting parties about complex legal rules, this Article also develops and critiques several alternative justifications for “clause-forcing” rules that encourage sophisticated parties to draft express contract terms. Such terms could facilitate the activities of avid comparison shoppers, reviewers, and consumer advocates. Comprehensive written terms also may promote ex post legal clarity and thereby reduce the costs of resolving disputes. Finally, exculpatory clauses allow parties to contract out of the comparatively expensive legal system of dispute resolution in favor of a regime governed by informal social norms. On this account, clause-forcing rules encourage sophisticated drafting parties to signal their preference for a norm-governed relationship, and lawmakers then demarcate the boundary between law and norms by deciding whether to enforce exculpatory clauses. The normative desirability of these clause-forcing rules is unclear, but my exploration of these alternative justifications shows the conceptual poverty of accounts that presume express contract terms inform the majority of unsophisticated parties
Risico inventarisatie van schade door ethyleen bij tussenplanten : effecten van tomaat op tussengeplante komkommer en tomaat
Bij een herfstteelt van trostomaten op goten is het aantrekkelijk om in de winter tomaten of komkommers tussen te planten. Door het grotendeels weg laten zakken van het oude gewas onder de goot en het jonge gewas op de goot te zetten, kan de teeltwisseling met een minder groot gat in de productie verlopen. Omdat trostomaten aan de plant volledig doorkleuren bestaat in principe de kans dat de ethyleen die gevormd wordt door de rijpende vruchten schade kan geven aan het jonge tussengeplante gewas. Bij tomaat is in 2000 op enkele bedrijven trosrui geconstateerd bij het tussengeplante toma tengewas. Hierbij werd gedacht aan mogelijke ethyleenschade. Ethyleen is een gasvormige, planteigen stof die als groeiregulator (hormoon) bij zeer veel verschillende fysiologische processen betrokken is. Het beïnvloedt o.a. bloei, bladgroei en lengtegroei van de spruit (Abeles et al., 1992). Als er externe bronnen zijn van ethyleen dan is er al snel sprake van schade. Symptomen van ethyleenschade zijn o.a. afwijkende kiemplanten, bloemrui, trosrui, afwijkende bladstand, bladval en stagnatie van de vegetatieve groei. Ernstige ethyleenschade uit zich direct in bladvergeling, maar soms treedt er verdekt wat lichte schade op die toch blijkt te leiden tot productiederving. Ethyleen komt in de buitenlucht standaard voor in een concentratie van 1 – 5 ppb (Abeles et al., 1992), maar kan in stedelijke gebieden tot wel 100 keer hoger worden. Ethyleen kan dus als luchtvervuiling een kas binnenkomen, of ophopen ten gevolge van een slecht afgestelde brander (Hanan, 1973, Esmeijer, 1999). Een andere bron van ethyleen is een gewas met doorkleurende vruchten zoals tomaat (Reid, 1988). In het geval van tussenplanten in de winterperiode zou dit problemen kunnen opleveren. In het verleden werd ook wel tussengeplant, maar leidde dit nooit tot problemen, omdat de vruchten los geoogst werden en nooit zo lang doorgekleurd in het gewas aanwezig bleven. Bovendien werd er alleen tussengeplant in de zomermaanden als er relatief veel gelucht werd. Bij tussenplanten in de winter van komkommers bij tomaat gaat het om een situatie waarin de luchtramen vaak gesloten zijn en er weinig licht beschikbaar is. De meeste gewassen zijn in die omstandigheden gevoelig voor schade, en naar verwachting zullen jonge, snel groeiende komkommerplanten op die regel geen uitzondering zijn
Scanning Electron Microscopy Study of Biofilms on Silicone Voice Prosthesis
Patients after laryngectomy often receive silicone made voice prostheses fot speech rehabilitation. The prosthesis is inserted in a shunt between the trachea and the digestive tract. As the prosthesis is placed in a nonsterile environment it becomes rapidly colonized by microorganisms eventually leading to failure and frequent exchange of the implant. In this study, explanted Groningen Button silicone voice prostheses were used to investigate by scanning electron microscopy the biofilm developing on the implant. Two main types of microbial colonization forms could be distinguished. Firstly, macroscopically visible, single colonies dominating on the esophagus side of the prosthesis were found, which were built up of mainly yeast cells. Secondly, thin microbial films on the areas in between were seen in which bacteria were the dominating organisms. In both colonization forms, mixed biofilms of mainly cocci and yeasts could also be found
Smaakonderzoek biologische geteelde producten 2000 : tomaat en komkommer
Er is geïnventariseerd wat de mogelijke knelpunten in smaak zijn bij de gewassen tomaat en komkommer aan de hand van kleinschalige oriënterende smaakproeven en metingen met het PBG smaakmodel. Daarnaast is aan de hand van literatuuronderzoek en oriënterende smaakproeven nagegaan wat mogelijke knelpunten bij een smaakverbetering zijn en welke teeltmaatregelen eventueel toegepast zouden kunnen worden. Op het PBG in Horst zijn proeven uitgevoerd om een biologisch teeltsysteem te ontwikkelen en te optimaliseren, waarbij glasgroenten van een hoogwaardige kwaliteit milieuvriendelijk en rendabel worden geproduceerd. Uit deze proeven zijn enkele rassen komkommer en tomaat op smaak onderzocht. Daarnaast is van enkele biologisch telende tuinders product onderzocht. Tenslotte is biologisch geteeld product uit het handelskanaal op smaak onderzocht
Design and analysis of coupling methods for modular endoprosthetic systems as an alternative to the conical coupling
Modular endoprostheses are often used in bone tumor management. However, the conical coupling that connects the various modules has several shortcomings. As an alternative, four new couplings have been developed. To find out if they have sufficient strength and show no movement during loading, each coupling was analysed using the finite element method. Bolt force and friction coefficient was varied to examine their influence. From the analysis it was concluded that coupling B, a dovetail coupling, meets all requirements and is the best alternative to the conical coupling. Sensitivity to bolt force and friction coefficient is very limited
The Presampler for the Forward and Rear Calorimeter in the ZEUS Detector
The ZEUS detector at HERA has been supplemented with a presampler detector in
front of the forward and rear calorimeters. It consists of a segmented
scintillator array read out with wavelength-shifting fibers. We discuss its
desi gn, construction and performance. Test beam data obtained with a prototype
presampler and the ZEUS prototype calorimeter demonstrate the main function of
this detector, i.e. the correction for the energy lost by an electron
interacting in inactive material in front of the calorimeter.Comment: 20 pages including 16 figure
Spring-Charged Particles Model to Improved Shape Recovery:An Application for X-Ray Spinal Segmentation
Deformable models are widely used in medical image segmentation methods, to find not only single but also multiple objects within an image. They have the ability to follow the contours of an object of interest, define the boundary of ROI (Region Of Interest) and improve shape recovery. However, these methods still have limitations in cases of low image quality or clutter. This paper presents a new deformable model, the Spring-Charged Particles Model (SCPM). It simulates the movement of positively charged particles connected by springs, attracted towards the contour of objects of interest which is charged negatively, according to the gradient-magnitude image. Springs prevent the particles from moving away and keep the particles at appropriate distances without reducing their flexibility. SCPM was tested on simple shape images and on frontal X-ray images of scoliosis patients. Artificial noise was added to the simple images to examine the robustness of the method. Several configurations of springs and positively charged-particles were evaluated by determining the best spinal segmentation result. The performance of SCPM was compared to the Charged Fluid Model (CFM), Active Contours, and a convolutional neural network (CNN) with U-Net architecture to measure its ability for determining the curvature of the spinal column from frontal X-Ray images. The results show that SCPM is better at segmenting the spine and determining its curvature, as indicated by the highest Area Score value of 0.837, and the lowest standard deviation value of 0.028
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