A note on four nonradioactive labeling systems for dot hybridization detection of potato viruses

Des clones d'ADN complémentaire ont été fabriqués à partir des ARN génomiques des virus S (PVS), X (PVX) et Y (PVY) de la pomme de terre (Solarium tuberosum). Les clones ont été sélectionnés pour leur spécificité par l'hybridation avec divers ARN viraux. Les clones S12 de PVS et X6 de PVX se sont avérés très spécifiques à l'ARN de PVS et PVX respectivement, alors que le clone Y10 de PVY a hybride fortement à l'ARN du PVY et faiblement à l'ARN du PVS. Quatre systèmes commerciaux non radioactifs de marquage des acides nucléiques et de détection ont été comparés entre eux et avec le marquage radioactif traditionnel de la sonde au 32P. La détection colorimétrique de sondes d'ADN marquées à la digoxygénine permet de déceler 1 ng de virions (60 pg d'ARN), soit une sensibilité du même ordre que l'autoradiographie avec des sondes marquées au phosphore radioactif. Les sondes sulfonées, biotinylées et marquées à la peroxydase ont été moins sensibles en permettant la détection de 600 pg d'ARN viral.Complementary DNA clones of genomic RNAs of potato (Solarium tuberosum) viruses S (PVS), X (PVX) and Y (PVY) were produced and tested for their capacity to hybridize with various plant virus RNAs. PVS clone S12 and PVX clone X6 were found to be very specifie to PVS and PVX RNA respectively, whereas PVY clone Y10 strongly hybridized with PVY RNA and weakly with PVS RNA. Four commercial, nonradioactive Systems of nucleic acid labeling and detection were compared to the usual 32P-labeled probe using dot hybridization experiments. Colorimetric detection of digoxigenin-labeled DNA probes gave a level of sensitivity of 1 ng of virions (60 pg of RNA), similar to autoradiography of 32P-labeled probes. Sulfonated, biotinylated and peroxidase-labeled probes were slightly less sensitive, allowing detection of 600 pg of viral RNA

Perceptual grouping based on iterative multi-scale tensor voting

Abstract. We propose a new approach for perceptual grouping of oriented segments in highly cluttered images based on tensor voting. Segments are represented as second-order tensors and communicate with each other through a voting scheme that incorporates the Gestalt principles of visual perception. An iterative scheme has been devised which removes noise segments in a conservative way using multi-scale analysis and re-voting. We have tested our approach on data sets composed of real objects in real backgrounds. Our experimental results indicate that our method can segment successfully objects in images with up to twenty times more noise segments than object ones.

Optical microscopy via spectral modifications of a nano-antenna

The existing optical microscopes form an image by collecting photons emitted from an object. Here we report on the experimental realization of microscopy without the need for direct optical communication with the sample. To achieve this, we have scanned a single gold nanoparticle acting as a nano-antenna in the near field of a sample and have studied the modification of its intrinsic radiative properties by monitoring its plasmon spectrum.Comment: 6 pages, 4 figures (color

Experimental study of fire containment using water mist curtains in a reduced-scale deck of a ro-ro ship

Experiments have been conducted to evaluate the containment of smoke and heat using water mist curtains in a model setup of a ro-ro ship's cargo deck with a scale of 1:13, providing practical insights into the application of such fire protection systems in the cargo deck as well as valuable data for future numerical simulations. In this regard, the requirements of the international convention of Safety of Life at Sea (SOLAS) are studied for the side openings of so-called ‘open decks’ in comparison with ‘closed decks’, especially to examine the feasibility of using water mist curtains for creating isolated subdivisions in the ro-ro space as a fire management strategy. The water mist curtains are created with one or two rows of water mist nozzles at pressures ranging from 3 to 8 bar, while the source of smoke and heat is a liquid pool fire, and inert cargo items are used in some experiments. Correspondingly, the interaction between the water mist curtain(s) and the fire is evaluated in terms of its heat release rate, and the containment effect is quantified via measurements of smoke flow through the deck and through the windows, concentrations of gaseous species, as well as gas temperatures at various key locations. The study shows that water mist curtains have a strong effect on fire dynamics and smoke propagation, but containment is dependent on the configuration of side openings and the location of fire, among other important factors

Translational and Regulatory Challenges for Exon Skipping Therapies

Several translational challenges are currently impeding the therapeutic development of antisense-mediated exon skipping approaches for rare diseases. Some of these are inherent to developing therapies for rare diseases, such as small patient numbers and limited information on natural history and interpretation of appropriate clinical outcome measures. Others are inherent to the antisense oligonucleotide (AON)-mediated exon skipping approach, which employs small modified DNA or RNA molecules to manipulate the splicing process. This is a new approach and only limited information is available on long-term safety and toxicity for most AON chemistries. Furthermore, AONs often act in a mutation-specific manner, in which case multiple AONs have to be developed for a single disease. A workshop focusing on preclinical development, trial design, outcome measures, and different forms of marketing authorization was organized by the regulatory models and biochemical outcome measures working groups of Cooperation of Science and Technology Action: "Networking towards clinical application of antisense-mediated exon skipping for rare diseases." The workshop included participants from patient organizations, academia, and members of staff from the European Medicine Agency and Medicine Evaluation Board (the Netherlands). This statement article contains the key outcomes of this meeting.status: publishe