456 research outputs found
Improving therapeutic potential of GDNF family ligands
The last decade has been a frustrating time for investigators who had envisioned major advances in the treatment of Parkinson's disease using neurotrophic factors. The first trials of glial cell line-derived neurotrophic factor for treating Parkinson's disease were very promising. Later blinded control trials were disappointing, not reaching the predetermined outcomes for improvement in motor function. Consideration of the problems in the studies as well as the biology of the neurotrophins used can potentially lead to more effective therapies. Parkinson's disease presents a multitude of opportunities for the cell biologist wanting to understand its pathology and to find possible new avenues for treatment.Peer reviewe
Estimating surface areas of mesh objects - A novel approach for signed distance fields
A tool was developed for surface area estimation of mesh model objects. The tool used signed distance fields together with ray mapping and constructive solid geometry operations to create solids with excluded overlapping surfaces. The goal of the study was to get an area estimation accuracy of at least 95%. The purpose of the tool was to be used inside the Cadmatic application for calculating paint area surfaces of models, especially on hull models.
Other tools using signed distance fields are also available. The novelty in the developed tool is the possibility to calculate signed distance fields simultaneously on a large number of objects, and ray mapping taking care of any overlapping surfaces between the objects. The tool creates a single solid object that represents all inserted mesh objects, and the surface area estimation is done on this solid.
The results show a sufficient area estimation accuracy, and acceptable runtimes even when applied on hundreds of mesh objects. Other objects, which should not be part of the surface area estimation, may overlap with the objects of interest and create so called hidden surfaces. These hidden surfaces could successfully be excluded from the total surface using constructive solid geometry operations.Ett verktyg utvecklades för ytarea-uppskattning av 3D-CAD modellobjekt. Målet med studien var att få en areauppskattningsnoggrannhet på minst 95 %. Syftet med verktyget var att användas i Cadmatic-applikationen för att beräkna målytsarea på modeller, speciellt på skrovmodeller.
Andra verktyg som använder signerade avståndsfält är också tillgängliga. Det nya i det utvecklade verktyget är möjligheten att beräkna signerade avståndsfält samtidigt på ett stort antal objekt, och strålkartläggning som tar hand om eventuella överlappande ytor mellan objekten. Verktyget skapar ett enda fast objekt som representerar alla infogade nätobjekt, och ytareauppskattningen görs på detta solida objekt.
Resultaten visar en tillräcklig noggrannhet för areauppskattning och acceptabla körtider även när de appliceras på hundratals objekt. Andra objekt som inte bör ingå i ytareauppskattningen, kan ändå överlappa de intressanta objekten och skapa så kallade dolda ytor. Dessa dolda ytor kunde framgångsrikt uteslutas från den totala ytan med hjälp av konstruktiva solidgeometrioperationer
Suorasanaisia kirjoitelmia
Sisältää: Virsiä / suom. Alpo Noponen. En voi: kaksinäytöksinen perhekuvaus / suom. O. Manninen. Salamiin kuninkaat: viisinäytöksinen murhenäytelmä / suom. O. Manninen. Suorasanaisia kirjoitelmia / suom. Juhani Ah
- …