Automated brain tumour detection and segmentation using superpixel-based extremely randomized trees in FLAIR MRI

PURPOSE: We propose a fully automated method for detection and segmentation of the abnormal tissue associated with brain tumour (tumour core and oedema) from Fluid- Attenuated Inversion Recovery (FLAIR) Magnetic Resonance Imaging (MRI). METHODS: The method is based on superpixel technique and classification of each superpixel. A number of novel image features including intensity-based, Gabor textons, fractal analysis and curvatures are calculated from each superpixel within the entire brain area in FLAIR MRI to ensure a robust classification. Extremely randomized trees (ERT) classifier is compared with support vector machine (SVM) to classify each superpixel into tumour and non-tumour. RESULTS: The proposed method is evaluated on two datasets: (1) Our own clinical dataset: 19 MRI FLAIR images of patients with gliomas of grade II to IV, and (2) BRATS 2012 dataset: 30 FLAIR images with 10 low-grade and 20 high-grade gliomas. The experimental results demonstrate the high detection and segmentation performance of the proposed method using ERT classifier. For our own cohort, the average detection sensitivity, balanced error rate and the Dice overlap measure for the segmented tumour against the ground truth are 89.48 %, 6 % and 0.91, respectively, while, for the BRATS dataset, the corresponding evaluation results are 88.09 %, 6 % and 0.88, respectively. CONCLUSIONS: This provides a close match to expert delineation across all grades of glioma, leading to a faster and more reproducible method of brain tumour detection and delineation to aid patient management

Risico-evaluatie voor geurproducten: een voorstudie

Er is weinig bekend over de risico's als gevolg van de blootstelling van consumenten aan geurstoffen uit consumentenproducten. Toevoeging van deze stoffen vindt plaats aan tal van consumentenproducten, varierend van wasmiddelen tot speelgoed. Passieve huiskamerparfums en spuitbusparfums zijn twee groepen producten die populair zijn in gebruik en die voor langdurige dan wel hoge blootstelling van de consument aan chemische stoffen kunnen zorgen. Voor het schatten van de mate van deze blootstelling is het softwareprogramma ConsExpo beschikbaar. Bijzondere aandacht gaat in deze studie uit naar het risico van het inademen van geurstoffen waarvan bekend is dat ze bij contact met de huid een allergische reactie kunnen veroorzaken. Door een gebrek aan een geaccepteerde methode echter, is het op dit moment niet mogelijk om te bepalen of dergelijke allergische reacties ook kunnen optreden bij inademing van deze geurstoffen. Dit onderwerp van de relatie tussen dermale en inhalatoire chemische allergie zal in de komende periode nader onderzocht worden in een pilot dierexperiment met twee geurstoffen. De groep 'geurproducten' zoals besproken in dit rapport omvat alle consumentenproducten die specifiek en alleen bedoeld zijn om een aangename geur te verspreiden in leefruimtes. Bijvoorbeeld ook geurkaarsen en wierook vallen hieronder. Uit een eerste inventarisatie is een enorme varieteit in het commerciele aanbod van geurproducten gebleken. De chemische samenstellingevan deze producten is complex en nadere kwantitatieve informatie over die samenstelling is vaak moeilijk te achterhalen. Ook door deze beperking is het volledig in kaart brengen van de risico's van alle stoffen in alle soorten geurproducten op dit moment niet mogelijk. Op basis van de beschikbare kennis wordt volstaan met enkele algemene aanbevelingen over waar men in de risico-evaluatie van een bepaald geurproduct op dient te letten.Little is known about the possible risks when consumers are exposed to fragrances. Fragrances are added to many consumer products, from detergents to toys. Passive room perfumes and spray perfumes represent two groups of products that are popular in use and may lead to high and long-lasting exposures for consumers. The degree of exposure can be estimated using the computer programme ConsExpo. Special attention is given in this study to the risk of inhaling fragrances known to produce allergic reactions upon dermal contact. Due to lack of an accepted method, however, it is not possible at this stage to determine if allergy will result when these fragrances are inhaled. Further research in this area is recommended. 'Scented products' as dealt with in the present report stands for all consumer products specifically intended for providing a pleasant odour in private and public living-spaces. This includes for instance scented candles and incense. An initial inventarisation shows an enormous variety of scented products available on the market. The chemical composition of scented products is complex; further quantitative information on that composition is difficult to obtain. Thus a complete inventarisation of the risks these products may pose is not possible at the present stage. Based on available knowlegde general recommendations are given as to points that require attention when evaluating the risk of a particular scented product.VW

Chemicals in toys. A general methodology for assessment of chemical safety of toys with a focus on elements

Alleen digitaal verschenenDit rapport bevat een erratum d.d. 26-01-2015 na pagina 234 Om de veiligheid van het gebruik van speelgoed te kunnen waarborgen, is in dit rapport een methode beschreven voor de afleiding van veilige limieten voor chemische stoffen in speelgoed. Deze methode combineert het gebruik van speelgoed door kinderen, en een veilige grenswaarde voor een stof. Het gebruik van deze methodologie wordt geillustreerd voor een aantal stoffen en een aantal typen speelgoed, zoals vingerverf en pluche speelgoed.This report contains an erratum d.d. 26-01-2015 after page 234 This report is written on request of DG Enterprise. A risk based methodology is presented that can be used to assess the safety of exposure to chemicals in toys. To demonstrate its use this methodology is applied to elements with the emphasis on toys intended for children under 36 months and on toys intended to be put in the mouth. The essence of the methodology is the assumption that exposure of children to chemicals in toys may not exceed a certain health-based level (Tolerable Daily Intake, or TDI in mg-kg bw-day). Since children are exposed to chemicals via other sources than toys we advocate that a certain percentage of the TDI should be allocated to toys. A number of arguments for the choice of this percentage are presented for elements. The actual choice of a percentage is a risk management decision and is not taken as such in this report.DG Enterpris

Sustained E2 antibody response correlates with reduced peak viremia after hepatitis C virus infection in the chimpanzee

Immune correlates of protection against hepatitis C virus (HCV) infection are not well understood. Here we investigated 2 naive and 6 immunized chimpanzees before and after intravenous challenge, 12 weeks after the last immunization, with 100 50% chimpanzee infectious doses (CID50) of heterologous genotype 1b HCV. Vaccination with recombinant DNA and adenovirus vaccines expressing HCV core, E1E2, and NS3-5 genes induced long-term HCV-specific antibody and T-cell responses and reduced peak viral load about 100 times compared with controls (5.91 +/- 0.38 vs. 3.81 +/- 0.71 logs, respectively). There was a statistically significant inverse correlation between peak viral loads and envelope glycoprotein 2 (E2)-specific antibody responses at the time of challenge. Interestingly, one vaccinee that had sterilizing immunity against slightly heterologous virus generated the highest level of E2-specific total and neutralizing antibody responses as well as strong NS3/NS5-specific T-cell proliferative responses. The other four vaccinees with low levels of E2-specific antibody had about 44-fold reduced peak viral loads but eventually developed persistent infections. In conclusion, vaccine-induced E2-specific antibody plays an important role in prevention from nonhomologous virus infection and may provide new insight into the development of an effective HCV vaccine.X115862sciescopu