A tool for task-based knowledge and specification acquisition

Knowledge acquisition has been identified as the bottleneck for knowledge engineering. One of the reasons is the lack of an integrated methodology that is able to provide tools and guidelines for the elicitation of knowledge as well as the verification and validation of the system developed. Even though methods that address this issue have been proposed, they only loosely relate knowledge acquisition to the remaining part of the software development life cycle. to alleviate this problem, we have developed a framework in which knowledge acquisition is integrated with system specifications to facilitate the verification, validation, and testing of the prototypes as well as the final implementation. to support the framework, we have developed a knowledge acquisition tool, TAME. It provides an integrated environment to acquire and generate specifications about the functionality and behavior of the target system, and the representation of the domain knowledge and domain heuristics. the tool and the framework, together, can thus enhance the verification, validation, and the maintenance of expert systems through their life cycles. © 1994 John Wiley & Sons, Inc.     

Lymphoma with bladder involvement and renal transplantation

Based on the case of a renal transplant recipient who developed a monoclonal B cell lymphoma with plasma cell differentiation, arising in the bladder, the authors discuss the responsibility of intensive immunosuppressant protocols in the development of post-transplantation lymphoproliferative syndromes. The Epstein-Barr virus favours the development of these lymphomas. The bladder is a rare site. Diagnosis was based on endoscopic resection with immunohistochemical analysis. The prognosis depends on the stage at the time of diagnosis. At an early stage, resection of the tumour combined with reduction of immunosuppressant therapy may be sufficient, but more aggressive treatment is required for more advanced stages. Anti-B lymphocyte monoclonal antibodies (CD21, CD24) give good results, especially in polyclonal forms and Epstein-Barr virus primo-infections. Anti-CD38 monoclonal antibodies are currently being investigated and appear to be very promising. Conventional radiotherapy and chemotherapy are disappointing.     

Biomonitoring of the genotoxic potential (micronucleus assay) and detoxifying activity (EROD induction) in the River Dadou (France), using the amphibian Xenopus laevis

Within the framework of a general survey of the water quality of the river Dadou (Tarn, France), different physico-chemical parameters were measured and an inventory of the fish population was made along the water course, around the Rassisse dam. With the aim of monitoring the potential genotoxic effects and the detoxifying activities induced in organisms exposed to the river water, two in vivo bioassays were performed in laboratory experiments, using larvae of the amphibian Xenopus laevis. The first was the micronucleus test, using red blood cells, and the second the assay of ethoxyresorufin-O-deethylase (EROD) induction in the liver of exposed animals. Eight water samples were taken from the river and at outlet points from the two major industrial activities of the studied section of the water course: a spar-fluor mine and a water treatment plant. Genotoxic impact and EROD induction were measured in the larvae. The effluent of the filter-washing process from the water treatment plant was found to be particularly genotoxic, even after dilution in pure reconstituted water, but no particular genotoxicity was found, either in Dadou river water, or in the effluents from the mine. On the other hand, most of the water samples tested produced a clear induction of EROD activity compared to the level of enzymatic activity found in the liver of larvae reared in the river water sampled upstream of the industrial activities. These results were interpreted taking into account (i) the high concentrations of pollutants (fluorine and manganese) measured in the river water, (ii) the very low population levels inventoried in the downstream section of the river and (iii) the possible interactions between the substances present in the river water, particularly the classical EROD inducers PAHs and PCBs.     

The potential impact of current animal research on the meat industry and consumer attitudes towards meat

Progress in animal nutrition, reproduction, quantitative genetics, and the development of molecular genetics, proteomics, and functional genomics open new perspectives for the meat sector. The most promising developments include a wider utilisation of molecular markers, the possibilities of semen sexing and the targeted use of nutrition to modify the composition of meat. The increased use of biotechnology will have a considerable impact on the economics of production of meat and further processed products. New technologies will increase the possibilities for product differentiation and improve homogeneity of live animals. The consumer and society in general will influence the direction of these developments. This review will focus on the long-term impact of new technologies for the meat production chain.     

First evidence of crystalline structure in conducting polythiophene

In order to optimize the properties of organic conducting polymers we analysed the effect of structure and dopant. The substitution of the carbon atoms in thiophene leads to a higher regularity in the corresponding polymer, obtained by electrochemical oxidation. The trifluoromethylsulphonate anion appears to be the best fitting dopant, allowing a 12 doping level of the polymer. Transmission electron microscopy reveals crystal patterns for this highly doped polymer. The obtained electron diffraction and X-ray data are consistent with a hexagonal lattice. The discussion of these results lead us to propose a coil structure for this organic conducting polymer.     

Nutrient budgets in the Saigon–Dongnai River basin: Past to future inputs from the developing Ho Chi Minh megacity (Vietnam)

Ho Chi Minh City (HCMC, Vietnam) is one of the fastest growing megacities in the world. In this paper, we attempt to analyse the dynamics of nutrients, suspended sediments, and water discharges in its aquatic systems today and in the future. The work is based on nine sampling sites along the Saigon River and one on the Dongnai River to identify the reference water status upstream from the urban area and the increase in fluxes that occur within the city and its surroundings. For the first time, the calculated fluxes allow drawing up sediment and nutrient budgets at the basin scale and the quantification of total nutrient loading to the estuarine and coastal zones (2012–2016 period). Based on both national Vietnamese and supplementary monitoring programs, we estimated the water, total suspended sediment, and nutrients (Total N, Total P, and dissolved silica: DSi) fluxes at 137 m³ year^?1, 3,292 × 10³ tonSS year^?1, 5,323 tonN year^?1, 450 tonP year^?1, and 2,734 tonSi year^?1 for the Saigon River and 1,693 m³ year^?1, 1,175 × 10³ tonSS year^?1, 31,030 tonN year^?1, 1,653 tonP year^?1, and 31,138 tonSi year^?1 for the Dongnai River, respectively. Nutrient fluxes provide an indicator of coastal eutrophication potential (indicator of coastal eutrophication potential), using nutrient stoichiometry ratios. Despite an excess of nitrogen and phosphorus over silica, estuarine waters downstream of the megacity are not heavily impacted by HCMC. Finally, we analysed scenarios of future trends (2025–2050) for the nutrient inputs on the basis of expected population growth in HCMC and improvement of wastewater treatment capacity. We observed that without the construction of a large number of additional wastewater treatment plants, the eutrophication problem is likely to worsen. The results are discussed in the context of the wastewater management policy.     

The effects of various basis image priors on MR Image MAP restoration

We extend a previously reported technique for Magnetic Resonance Image (MRI) restoration, using a physical model (spin equation) and corresponding basis images. We determine the basis images (proton density and nuclear relaxation times) from the MRI data and use them to obtain excellent restorations.Magnetic Resonance Images depend nonlinearly on proton density,, two nuclear relaxation times,T ₁ andT ₂, and two control parameters, TE and TR. We model images as Markov random fields and introduce four maximuma posteriori (MAP) restorations, nonlinear techniques using several different prior terms which reduce the correlated noise in the basis images, thereby reducing the noise in the restored MR images. The product and sum forms for basis (signal) and spatial correlations are discussed, compared and evaluated for various situations and features.     

Covalent immobilization of cytochrome P450 BM3 (R966D/W1046S) on glutaraldehyde activated SPIONs

Selective hydroxylation of the C‐H bond of saturated hydrocarbon chains at room temperature is the signature of an invaluable biocatalyst, cytochrome P450 BM3 from Bacillus megaterium. Despite this remarkable ability, because of the enzyme's inherent low stability and dependence on electron supply by expensive NADPH, developing stable and economic BM3 systems is a challenging subject. To improve BM3 stability, facilitate its reuse, and reduce the process cost, this study suggests covalent immobilization of R966D/W1046S P450 BM3 on glutaraldehyde pre‐activated super paramagnetic iron oxide nanoparticles (SPIONs). This double mutant consumes less expensive cofactors like NADH and BNAH and its immobilization on magnetic support facilitates its separation and reuse. Free and immobilized enzyme performances were evaluated by 10‐pNCA hydroxylation and BM3 selectivity (hydroxylation at ω (1–3) positions of a fatty acid) was confirmed in a reaction involving myristic acid. The enzyme activity recovery was up to 60 % with 100 % enzyme binding efficiency. BM3‐SPIONs were easily separated from the reaction medium by applying a magnet, and recycled for 5 times, after which they could still present half of their initial activity. The enzyme storage stability was significantly improved: after one month of storage at 4 °C, the immobilized enzyme showed 80 % residual activity toward NADH while the soluble enzyme was inactive after a week. Binding an enzyme to fabricated SPIONs is a promising technique to increase enzyme stability and prevent downstream contamination in biocatalytic processes. In this context, BM3‐SPIONs can be a practical model system in cost‐effective large‐scale applications of such enzymes.

     

The preparation of hybrid trimer by cyclo-oligomerization of TDI and HDI and its curing process with polyols to form elastic PU coating

The hybrid cyclic isocyanate trimer with appropriate functionality and good solvent tolerance which can be used as a building block to construct polyurethane (PU) coatings was prepared by cyclo-oligomerization of toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI). Among all the tested catalysts, the self-made catalyst 3-(trimethylammonio)propyl carbonate (Cat. 4) was found to possess enough catalytic efficiency to confirm the NCO conversion to reach about 50% with both high (1 wt%) and low (0.25 wt%) catalyst loading at low temperature (40°C). The IR and NMR results proved the formation of a hybrid trimer, while HPLC results showed hybrid TDI/HDI trimer predominated in the product and only trace amounts of TDI monomer (<0.5 wt%) and oligomer with higher degree of polymerization (DP) remained. Furthermore, the formed hybrid oligomer exhibited excellent solvent tolerance to benzene, chlorinated, and acetate solvents. Consequently, Cat. 4 was demonstrated to be a suitable catalyst for cyclo-oligomerization since it not only possessed enough catalytic efficiency at low temperature but also hardly resulted in higher DP oligomer. Furthermore, the curing process with PTHF-r-PEO polyol was conducted as a pilot experiment to form PU coatings at room temperature. The disappearance of NCO group in IR spectrum as well as higher storage modulus against loss modulus implied the successful curing process. The strain–stress test showed the high tensile strength of formed PU coating, whereas the rheological test and dynamic mechanical analyzer proved the formed PU coating was a typical elastic material with good crosslink structure. These results indicate the promising potential of formed PU made from hybrid TDI/HDI trimer for coating applications.