An efficient distributed algorithm for generating and updating multicast trees

As group applications are becoming widespread, efficient network utilization becomes a growing concern. Multicast transmission represents a necessary lower network service for the wide diffusion of new multimedia network applications. Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in networks) is prohibitively expensive. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem, allowing the construction of effective distribution trees using a coordination protocol among the network nodes. Furthermore, we propose a novel distributed technique for dynamically updating the multicast tree. The approach proposed has been implemented and extensively tested both in simulation, and on experimental networks. Performance evaluation indicates that the distributed algorithm performs as well as the centralized version, providing good levels of convergence time and communication complexity.     

Pigmented uveal tumours in a transgenic mouse model

Lectins are sensitive probes which bind carbohydrate structures specifically. In this study, we modified the lectin staining procedure for sensitive detection of carbohydrate structures in formalin-fixed, paraffin-embedded sections of normal and heterologous serum-induced fibrotic livers. The liver sections were heated in hot distilled water at 100 degrees C for 10 min (thermo-treatment: TT), and then stained with 24 different lectins. In comparison with the results from sections without TT (nonTT), enhanced and/or alternated staining patterns of 19 lectins were demonstrated in sections with TT, and enhanced staining of Vicia villosa agglutinin seen in Kupffer cells was noted. Interestingly, no positive staining was seen with Dolichos biflorus agglutinin, peanut agglutinin or soybean agglutinin (SBA), which recognize O-linked carbohydrate chains, in Kupffer cells of non-TT sections, but strong positive staining was demonstrated in those of TT sections. SBA-positive staining in the cytoplasm of some scattered hepatocytes located in the periportal and perifibrous zones and central zone of pseudolobules was demonstrated only in the fibrotic liver sections with TT. Such findings indicate the heterogeneity of hepatocytes in the liver with fibrosis. Formalin fixation causes masking of lectin binding sites, especially O-linked carbohydrate chains, and TT may recover such masking reactions. TT improved the staining reactions for many lectins in formalin-fixed, paraffin-embedded liver sections, and new staining patterns appear after TT. Modified TT staining procedures may be useful for the diagnosis and prognosis of liver fibrosis.     

White matter lesion detection in multiple sclerosis: improved interobserver concordance with multispectral MRI display

The histopathology specimens from 256 consecutive prostatectomies were retrospectively analysed and classified into three categories namely BPH alone, BPH and an inflammatory lesion and adenocarcinoma. Mode of presentation (acute urine retention versus prostatism) as well as short term post-operative complications, namely, haemorrhage and genitourinary infection were compared in the three histological categories to study the impact of histology on clinical presentation and complications. There were no significant differences between the three categories neither in presentation nor in complications. We conclude that prostate gland histology neither correlates with the onset of acute urine retention nor with the surgical complications studied in this report.     

Thallium-201 as a positive indicator for lung neoplasms: preliminary experiments

Thallium-201 was given to 71 patients with various pulmonary diseases. Positive uptake was noted in primary malignant neoplasms and also in 6 cases of Hodgkin's lymphoma. No uptake was seen in pulmonary diseases other than active tuberculosis. A disadvantage is the high myocardial accumulation of this radionuclide which impairs proper visualization of paracardiac neoplasms.     

Formation of neutral molecules of potential stellar interest by neutralisation of negative ions in a mass spectrometer. The application of experiment and molecular modelling in concert

This paper is a modified version of a lecture which describes the synthesis, structure and reactivity of some neutral molecules of stellar significance. The neutrals are formed in the collision cell of a mass spectrometer following vertical Franck-Condon one electron oxidation of anions of known bond connectivity. Neutrals are characterised by conversion to positive ions and by extensive theoretical studies at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-31G(d) level of theory. Four systems are considered in detail, viz (i) the formation of linear C(4) and its conversion to the rhombus C(4), (ii) linear C(5) and the atom scrambling of this system when energised, (iii) the stable cumulene oxide CCCCCO, and (iv) the elusive species O(2)C-CO. This paper is not intended to be a review of interstellar chemistry: examples are selected from our own work in this area.     

Personality theories facilitate integrating the five principles and deducing hypotheses for testing.

Comments on the original article "A New Big Five: Fundamental Principles for an Integrative Science of Personality," by Dan P. McAdams and Jennifer L. Pals (see record 2006-03947-002). In presenting their view of personality science, McAdams and Pals (April 2006) elaborated the importance of five principles for building an integrated science of personality. These principles are stances on evolution and human nature, dispositional signatures, characteristic adaptations, life narratives, and the differential role of culture. Their main emphasis involved differentiating these principles and indicating that they are all relevant to understanding personality. The discussion by McAdams and Pals certainly illuminates the various aspects of personality, but it also cries out for some greater, more systematic integration of the five principles into particular kinds of personality. It is not yet possible, in their approach, to identify different types of personality orientation and to evaluate the relative effectiveness of these orientations. As presented, their approach may be considered a start but hardly a finish. Here, the current author suggests that the metatheory of personality theories that he has proposed (Maddi, 1969/1996) could accelerate the needed integration of the five proposed principles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance analysis of parallel Schwarz preconditioners in the LES of turbulent channel flows

We present a comparative study of parallel Schwarz preconditioners in the solution of linear systems arising in a Large Eddy Simulation (LES) procedure for turbulent plane channel flows. This procedure applies a time-splitting technique to suitably filtered Navier–Stokes equations, in order to decouple the continuity and momentum equations, and uses a semi-implicit scheme for time integration and finite volumes for space discretisation. This approach requires the solution of four sparse linear systems at each time step, accounting for a large part of the overall simulation; hence the linear system solvers are a crucial component in the whole procedure. Several preconditioners are applied in the simulation of a reference test case for the LES community, using discretisation grids of different sizes, with the aim of analysing the effects of different algorithmic choices defining the preconditioners, and identifying the most effective ones for the selected problem. The preconditioners, coupled with the GMRES method, are run within SParC-LES, a recently developed LES code based on the PSBLAS and MLD2P4 libraries for parallel sparse matrix computations and preconditioning.     

Photophysical and charge-transporting properties of the copolymer SuperYellow

Conjugated copolymers are important materials for organic light-emitting diodes. Here, an investigation of the photophysical and charge-transporting properties of the prototypical poly(p-phenylene vinylene) based copolymer SuperYellow (SY) is reported. The study also investigated the effect of processing conditions by comparing the properties of spin-coated and solution-cast films. For both types of films, the results of time-resolved fluorescence and photoluminescence quantum yield measurements are similar. The high photoluminescence quantum yield of 60% and its independence of processing conditions shows the effectiveness of the bulky side groups in preventing concentration quenching of fluorescence. Time of flight measurements of charge mobility in both spin-coated and solution-cast films also showed similar results, with mobilities in the range 10^?6–10^?7 cm²/V s for both films. These results provide important information about a widely used copolymer and show that a good polymer light-emitting diode material can have low mobility.     

Modeling,classifying and annotating weakly annotated images using Bayesian network

In this paper, we propose a probabilistic graphical model to represent weakly annotated images. We consider an image as weakly annotated if the number of keywords defined for it is less than the maximum number defined in the ground truth. This model is used to classify images and automatically extend existing annotations to new images by taking into account semantic relations between keywords. The proposed method has been evaluated in visual-textual classification and automatic annotation of images. The visual-textual classification is performed by using both visual and textual information. The experimental results, obtained from a database of more than 30,000 images, show an improvement by 50.5% in terms of recognition rate against only visual information classification. Taking into account semantic relations between keywords improves the recognition rate by 10.5%. Moreover, the proposed model can be used to extend existing annotations to weakly annotated images, by computing distributions of missing keywords. Semantic relations improve the mean rate of good annotations by 6.9%. Finally, the proposed method is competitive with a state-of-art model.