Balloon assisted technique for closure of large atrial septal defects

Amplatzer device closure of large atrial septal defects is challenging. A large device tends to malalign with the plane of the interatrial septum or prolapses through the defect. We describe a balloon assisted technique which has been successfully used in over 300 cases without a single technical failure.peer-reviewe

The Dichotomy of Conjunctive Queries on Probabilistic Structures

We show that for every conjunctive query, the complexity of evaluating it on a probabilistic database is either \PTIME or #\P-complete, and we give an algorithm for deciding whether a given conjunctive query is \PTIME or #\P-complete. The dichotomy property is a fundamental result on query evaluation on probabilistic databases and it gives a complete classification of the complexity of conjunctive queries

Regulation of the urokinase-type plasminogen activation system in oral squamous carcinoma cell lines by the β6 integrin subunit

Over-expression of components of the urokinase system is well documented in cancer and is thought to enable tumour cells to migrate and invade. Changes in integrin expression are also a common feature of tumours and have been linked to changes in protease activity. The αv integrin family has been correlated with cancer progression; particularly the αvβ6 integrin is neo-expressed in a number of epithelial carcinomas and has been associated with metalloproteinase expression. Oral see keratinocytes, which had been transfected to express different integrin subunits, were used in this study. Cells expressing αvβ6 showed enhanced urokinase-type plasminogen activator (uPA) secretion compared to control cells. This was unaffected by plating on a variety of matrix ligands including fibronectin. However, cells over-expressing αvβ6 showed decreased urokinase receptor (uPAR) mRNA and protein expression, associated with decreased cell surface plasminogen activation. Therefore, uPAR levels and cell surface plasminogen activation were inversely related to αvβ6 expression. The up-regulation of uPA secretion and down-regulation of uPAR expression and function by the αvβ6 integrin was mediated through the unique 11 amino acid extension of the β6 cytoplasmic tail. Transfection of αvβ6 into melanoma cell lines did not affect the urokinase system, suggesting this is cell-specific. Morpholino antisense oligonucleotides targeted against the αv and β6 integrins and an inducible β6 gene expression system were also used in order to confirm effects of αvβ6 on the urokinase system. The roles of αvβ6 and uPA in cell migration and invasion were also investigated. Expression of αvβ6 into the keratinocytes promoted only fibronectin-dependent cell migration that was not uPA dependent but required plasmin activity. The dual regulation of the urokinase system by αvβ6 integrin suggests a complex system where levels of proteolysis in cancer invasion are precisely regulated

What do Neural Machine Translation Models Learn about Morphology?

Neural machine translation (MT) models obtain state-of-the-art performance while maintaining a simple, end-to-end architecture. However, little is known about what these models learn about source and target languages during the training process. In this work, we analyze the representations learned by neural MT models at various levels of granularity and empirically evaluate the quality of the representations for learning morphology through extrinsic part-of-speech and morphological tagging tasks. We conduct a thorough investigation along several parameters: word-based vs. character-based representations, depth of the encoding layer, the identity of the target language, and encoder vs. decoder representations. Our data-driven, quantitative evaluation sheds light on important aspects in the neural MT system and its ability to capture word structure.Comment: Updated decoder experiment