The ToxicFarm Integrated Cooperation Framework for Virtual Teams

Developing a collaboration solution, that scales to an entire organization, that offers an integrated collection of cooperation tools, that is general enough to address a large range of applications, and that is easy to deploy for most people, is still an open challenge. This paper presents ToxicFarm services that are an integral part of a framework for hosting Internet virtual teams. The originality of this work is in providing a synthesis between contributions from different domains, including version management in software engineering, process management in data engineering, and awareness in groupware tools. The paper describes the overall services offered, discusses design choices for their integration and implementation, presents relations with existing work and describes their use in several emerging e-business application domains, such as e-finance, e-learning and e-telecom.     

A functional analysis of the network: A prerequisite for deregulating the telecommunications industry

Due to the obvious inefficiency of regulatory authorities, the introduction of potential competition in the markets of natural monopolies has recently been emphasized in theoretical publications. In spite of its limitations the framework of contestable markets has been the analytical background of decisions in various industries. The purpose of this paper is to discuss the application of these theories to the telecommunications network as a whole. Econometric models have failed to establish that the telecommunications cost function is subadditive, mainly because networks are heterogeneous from an economic point of view: information is transmitted with increasing returns to scale, while there are growing economies of scope between the data processing industry and the handling, by digital switching equipment, of the calls’ content and of the signalling and addressing information. To allow for this current technical evolution the deregulation process should dissociate the transmission network, which is a natural monopoly, and the traffic routing networks, which could be gradually opened to a limited competition. In this new structure there would be a wholesale market in which a regulated monopoly would rent transmission facilities (leased circuits, dedicated access loops, …) and a competitive retail market in which operators would sell traffic and value added networks to residence and business customers.     

Evaluation of Spray-Drying as a Method to Prepare Microparticles for Controlled Drug Release

The possibility to obtain microcapsules or microspheres for controlled release by spray-drying is evaluated. Drugs of different solubilities like theophylline and sodium sulfamethazine, with Eudragit RS as coating polymer, are chosen.

The polymer is used, either dissolved in an hydroalcoholic solution or suspended (pseudolatex) in water, in different weight ratios with the drug. The obtained solution or suspension is spray-dried.

Scanning electron microscope analysis of the powders reveals no sign of microencapsulation. Moreover, only a fraction of the particles has a spherical shape.

For each spray-dried powder, a part of the obtained particles is compressed into tablets, and the rest is stored.

Dissolution studies in distilled water at 37 C are performed on powders and tablets.

While the uncompressed microparticles do not give any controlled release, the tablets show an ability in slowing down drug delivery greater than the one obtained with the traditional methods.     

Bound states of3He in3He-4He mixture films

³He atoms dissolved in super fluid⁴He may form aimers (³He)₂ in twodimensional (2D) geometries. We study dimer formation in films of dilute³He-⁴He mixture. After designing a schematic³He-⁴He interaction potential we calculate the dimer binding energy for various substrates. It is shown that³He impurity states localized near the substrate give rise to the largest magnitudes of the binding energies.Unité de Recherche des Universités Paris XI et Paris VI associée au CNRS.     

Influence de la tarification horaire sur le trafic téléphonique

As the evening peakload of trunk traffic became higher than the morning one, a new time-of-day pricing was initiated in France on June 1985. The effects of this tariff change on the traffic profile and the telephone revenues were previously estimated, using an econometric model, fitted from traffic observations provided by similar experiments carried out in Germany and Switzerland. This model, based on probabilistic choice theory, uses the Logit formulation adapted to the case of a continuous set of options (times-of-day), and provides simulations of traffic trade-offs due to changes in the time-of-day pricing. Data collected since June 1984 enable us to measure the actual effects of the new tariffication. Compared with the model forecasts, these observations show a good fitting for the 6 p.m. to 8.30 p.m. period (the 8 p.m. peak-load decrease is consistent with the forecast); in the late evening however, traffic is higher than expected. These new data allowed us to improve the formulation and the fitting of the model; these recent developments are presented here.     

Uses of change-over designs and repeated measurements in sensory and consumer studies

The paper illustrates two statistical methods, the design and analysis of sensory experiments taking into account the effects of serving order and previously assessed treatment and the analysis of experiments with time repeated measurements.

Change-over design experiments balance both presentation order and carry-over effects. The proper analysis of variance allows the testing of these effects and the estimation of product means adjusted for carry-over effect.

Repeated measurements occur when groups are being compared over time. Either a corrected split-plot or a multivariate analysis of variance (MANOVA) with measurements at different times forming the variable should be adopted to allow proper tests for the time effect and for its interaction with the group effect.

The usefulness of change-over designs with an appropriate analysis and repeated measurement analysis will be demonstrated using sensory experiments involving trained assessors and consumers.     

Effects of oxygen diffusion on recombinant E. coli B (pTG201) plasmid stability,growth rate,biomass production,and enzyme activity in immobilized and free bacteria during continuous culture

The influence of oxygen diffusion on kinetic properties, plasmid instability, biomass production and enzyme production of recombinant Escherichia coli B containing plasmid pTG201 was investigated. The experiments were carried out using continuous cultures and two types of medium, with immobilized bacteria in carrageenan gel and free bacteria. The specific growth rate of immobilized bacteria was a monotonic function of dissolved oxygen (DO) level from 0% DO to 100% DO, and it increased 63% in L-Broth medium and 70% in minimal medium with respect to 0% DO, but the growth rate was quickly reduced above 75% DO (L-Broth medium) or 50% DO (minimal medium) in free bacteria. The specific growth rate was generally higher for free bacteria than for immobilized bacteria. The plasmid was substantially more stable at 0% than at 50% or 100% DO in both immobilized and free bacteria. Biomass production was proportional to the growth rate, and this in turn was greatly influenced by the DO concentration. Measurements of enzyme production showed that the enzyme activity was diminished in both immobilized and free bacteria when oxygen was eliminated. The observed increase in plasmid stability may have resulted from the disturbance of low growth rate and decreased expression of the enzyme.     

Titania as a Sintering Additive in Indium Oxide Ceramics

The influence of TiO₂ additives on the sintering behavior of In₂O₃ ceramics has been investigated. TiO₂ increases the densification rate, decreases the grain growth during the intermediate stage of sintering, and hinders the pore/boundary breakaway that can affect the final stage of sintering. For a given grain size, TiO₂ shifts the grain size/density trajectory toward higher densities. TiO₂ mainly acts by a second-phase mechanism, but it also may decrease the decomposition rate of In₂O₃.