Distributed Coordination and Workflow on the World Wide Web

This paper describes WebFlow, an environment thatsupports distributed coordination services on theWorld Wide Web. WebFlow leverages the HTTP Webtransport protocol and consists of a number of toolsfor the development of applications that require thecoordination of multiple, distributed servers.Typical applications of WebFlow include distributeddocument workspaces, inter/intra-enterprise workflow,and electronic commerce. In this paper we describe thegeneral WebFlow architecture for distributedcoordination, and then focus on the environment fordistributed workflow.     

Supernovae and gamma-ray bursts in the induced gravitational collapse paradigm

I review recent progress in the understanding of long, energetic (10⁵²–10⁵⁴ erg) gamma-ray bursts (GRBs) associated to supernovae (SN) Ib/c. This occurrence is explained within the Induced Gravitational Collapse (IGC) paradigm, following the sequence: 1) an initial binary system consists in a compact Iron-Carbon-Oxygen (FeCO) core and a neutron star (NS); 2) the FeCO core explodes, giving origin to a SN, and part of the SN ejecta accretes onto the NS which reaches its criticalmass and collapses to a black hole (BH) giving rise to a long GRB; 3) a new NS (ν-NS) is generated by the SN as a remnant. Observational consequences of this scenario are outlined.     

Effects of experimental endogenous hyperlipemia on circulating leukocytes and erythrocytes

Effects of hyperlipemia on circulating leukocytes and erythrocytes were studied in dogs which were given repeated, intravenous injections of a nonionic detergent, Triton WR-1339. Erythrocyte lipid concentrations increased from 3.6±0.9 mg/10¹⁰ cells in control animals to 9.3±1.5 mg in the hyperlipemic group. This increase was accompanied by a shift in the distribution of total fatty acids toward a higher percentage of saturated and monounsaturated acids. In contrast to the changes observed in erythrocytes, the leukocyte lipid content remained unaltered in dogs with serum cholesterol levels ranging from 500 to more than 2,000 mg/100 ml. Leukocyte counts rose whereas hematocrit values, hemoglobin concentrations, and erythrocyte counts decreased. Oxygen utilization studies showed no significant metabolic differences between leukocytes which were isolated from hyperlipemic or control animals. Circulating leukocytes in dogs with an endogenously induced hyperlipemia were shown therefore to maintain normal lipid concentrations and did not participate in lipophage formation, as reported for certain diet-induced lipemias.     

Lipid metabolism of acetate-1-14C by leukocytes from dogs fed an arteriosclerosis-inducing diet

Dogs were maintainedoon a control ration or on a semisynthetic diet, containing 5% cholesterol and 16% hydrogenated coconut oil, known to induce hyperlipemia and arteriosclerosis. Circulating leukocytes isolated from dogs fed the coconut oil containing diet were shown to incorporate 50% more radioactivity into lipids than control leukocytes when incubated with acetate-1-¹⁴C. This increase, expressed as dpm/mg of leukocyte DNA, was not specific for any particular lipid since the distribution of radioactivity between neutral lipids and phospholipids, as well as among their subfractions, was the same regardless of the diet fed. The labeling patterns observed suggest that leukocyte fatty acid synthesis from acetate occurs predominantly, and perhaps exclusively, by the chain elongation pathway.     

A test-driven approach to code search and its application to the reuse of auxiliary functionality

Context

Software developers spend considerable effort implementing auxiliary functionality used by the main features of a system (e.g., compressing/decompressing files, encryption/decription of data, scaling/rotating images). With the increasing amount of open source code available on the Internet, time and effort can be saved by reusing these utilities through informal practices of code search and reuse. However, when this type of reuse is performed in an ad hoc manner, it can be tedious and error-prone: code results have to be manually inspected and integrated into the workspace.

Objective

In this paper we introduce and evaluate the use of test cases as an interface for automating code search and reuse. We call our approach Test-Driven Code Search (TDCS). Test cases serve two purposes: (1) they define the behavior of the desired functionality to be searched; and (2) they test the matching results for suitability in the local context. We also describe CodeGenie, an Eclipse plugin we have developed that performs TDCS using a code search engine called Sourcerer.

Method

Our evaluation consists of two studies: an applicability study with 34 different features that were searched using CodeGenie; and a performance study comparing CodeGenie, Google Code Search, and a manual approach.

Results

Both studies present evidence of the applicability and good performance of TDCS in the reuse of auxiliary functionality.

Conclusion

This paper presents an approach to source code search and its application to the reuse of auxiliary functionality. Our exploratory evaluation shows promising results, which motivates the use and further investigation of TDCS.     

Low-cost telepresence for collaborative virtual environments

We present a novel low-cost method for visual communication and telepresence in a CAVEtrade-like environment, relying on 2D stereo-based video avatars. The system combines a selection of proven efficient algorithms and approximations in a unique way, resulting in a convincing stereoscopic real-time representation of a remote user acquired in a spatially immersive display. The system was designed to extend existing projection systems with acquisition capabilities requiring minimal hardware modifications and cost. The system uses infrared-based image segmentation to enable concurrent acquisition and projection in an immersive environment without a static background. The system consists of two color cameras and two additional b/w cameras used for segmentation in the near-IR spectrum. There is no need for special optics as the mask and color image are merged using image-warping based on a depth estimation. The resulting stereo image stream is compressed, streamed across a network, and displayed as a frame-sequential stereo texture on a billboard in the remote virtual environment     

Critical Role for the Protons in FRTL-5 Thyroid Cells: Nuclear Sphingomyelinase Induced-Damage

Proliferating thyroid cells are more sensitive to UV-C radiations than quiescent cells. The effect is mediated by nuclear phosphatidylcholine and sphingomyelin metabolism. It was demonstrated that proton beams arrest cell growth and stimulate apoptosis but until now there have been no indications in the literature about their possible mechanism of action. Here we studied the effect of protons on FRTL-5 cells in culture. We showed that proton beams stimulate slightly nuclear neutral sphingomyelinase activity and inhibit nuclear sphingomyelin-synthase activity in quiescent cells whereas stimulate strongly nuclear neutral sphingomyelinase activity and do not change nuclear sphingomyelin-synthase activity in proliferating cells. The study of neutral sphingomyelinase/sphingomyelin-synthase ratio, a marker of functional state of the cells, indicated that proton beams induce FRTL-5 cells in a proapoptotic state if the cells are quiescent and in an initial apoptotic state if the cells are proliferating. The changes of cell life are accompanied by a decrease of nuclear sphingomyelin and increase of bax protein.     

Realization of a New Inverter Circuit for Direct Photovoltaic Energy Feedback into the Public Grid

A new regulated utility interactive inverter for direct photovoltaic energy feedback to the mains has been realized. A modulated buck converter converts the photovoltaic dc current to a rectified 50-Hz sine wave current, and the following self-commutated half-bridge generates a 50-Hz sine wave current, which is fed into one phase of the public power grid. This nonclassical inverter needs only three power transistor switches and isolates the grid and the photovoltaic array using a commercial 50-Hz transformer. It acts as a current source, and due to pulsewidth modulation its output is a sine wave current with very low total harmonic distortion of one percent. The overall efficiency of the 1-kW prototype is at least 88 percent between 250 and 1000 W, and the projected efficiency is over 90 percent for 1-20 kW. Furthermore, a circuit which tracks the maximum power available from the photovoltaic generator has been developed. This circuit regulates the input power to its maximum by detecting the phase angle between the voltage and power ripples at the inverter input.