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

Energy efficient scheduling and allocation of tasks in sensor cloud

Wireless Sensor Network (WSN) is a class of ad hoc networks that has capability of self-organizing, in-network data processing, and unattended environment monitoring. Sensor-cloud is a cloud of heterogeneous WSNs. It is attractive as it can change the computation paradigm of wireless sensor networks. In Sensor-Cloud, to gain profit from underutilized WSNs, multiple WSN owners collaborate to provide a cloud service. Sensor Cloud users can simply rent the sensing services which eliminates the cost of ownership, enabling the usage of large scale sensor networks become affordable. The nature of Sensor-Cloud enables resource sharing and allows virtual sensors to be scaled up or down. It abstracts different platforms hence giving the impression of a homogeneous network. Further in multi-application environment, users of different applications may require data based on different needs. Hence scheduling scheme in WSNs is required which serves maximum users of various applications. We have proposed a scheduling scheme suitable for the multiple applications in Sensor Cloud. Scheduling scheme is based on TDMA which considers fine granularity of tasks. The performance evaluation shows the better response time, throughput and overall energy consumption as compared to the base case we developed. On the other hand, to minimize the energy consumption in WSN, we design an allocation scheme. In Sensor Cloud, we consider sparsely and densely deployed WSNs working together. Also, in a WSN there might be sparsely and densely deployed zones. Based on spatial correlation and with the help of Voronoi diagram, we turn on minimum number of sensors hence increasing WSN lifetime and covering almost 100 percent area. The performance evaluation of allocation scheme shows energy efficiency by selecting fewer nodes in comparison to other work --Abstract, page iv