Mécanisme de l’évolution des champs électromagnétiques dans un simulateur de grandes dimensions. Projet d’un simulateur semi-rhombique

The purpose of this paper is to evaluate theoretically and experimentally the transient electric field in anemp simulator. Using a time domain analysis, the mechanism of the field deformation can be analysed and consequently modifications can be introduced in the conception of new simulators (for example: rhombic simulator).     

Modélisation de l’impédance de transfert des câbles coaxiaux à blindages multiples

The shielding effectiveness of multishielded coaxial cables is determinated through the concept of the equivalent transfer impedance. The transfer impedance is computed from the main parameters of the coaxial structure. We describe in this paper the theoretical formulation to evaluate the amplitude of the disturbing voltage at the end of the cable flowed by the disturbing current. This result is used for the computation of the equivalent transfer impedance when the cable is made of various shields for exemple: homogeneous screens or braids. A comparison with the experimental results is also described.     

Quantification et détection

The basic detection problem consists in deciding on an optimal way between two possible hypotheses. This decision is made by comparing to an appropriate threshold the output of a processing system. The purpose of this paper is to study the consequences of a threshold quantization on the detection performance. Using various possible models of quantization we show that it creates in general a degradation of the performance. From this fact we introduce a new detection criterion using the concept of contrast and we show on some examples how this criterion is adapted to quantized detection problems.     

Large-scale production of a hypoallergenic preparation of F(ab′)2 fragments from bovine colostrum

A method for the production of bovine colostral F(ab′)₂ fragments at pilot-plant scale was developed. Optimum yield of immunoglobulins in colostral whey was obtained after rennet treatment of first milking colostrum. Pepsin digestion was carried out directly on the colostral whey at pH 3·8 for 4 h, which led to the complete digestion of immunoglobulins into F(ab′)₂ fragments. Elimination of β-lactoglobulin, the main immunogenic protein, was achieved by anion exchange on Duolite A560 at pH 6·0. The preparation was diafiltered with a 5000 Da membrane and the retentate spray-dried. The powder obtained contained approximately 34% F(ab′)₂ fragments, with an antibody activity three times higher than the initial colostrum.     

Macrophage-Mediated Melanoma Reduction after HP-NAP Treatment in a Zebrafish Xenograft Model

The Helicobacter pylori Neutrophil Activating Protein (HP-NAP) is endowed with immunomodulatory properties that make it a potential candidate for anticancer therapeutic applications. By activating cytotoxic Th1 responses, HP-NAP inhibits the growth of bladder cancer and enhances the anti-tumor activity of oncolytic viruses in the treatment of metastatic breast cancer and neuroendocrine tumors. The possibility that HP-NAP exerts its anti-tumor effect also by modulating the activity of innate immune cells has not yet been explored. Taking advantage of the zebrafish model, we examined the therapeutic efficacy of HP-NAP against metastatic human melanoma, limiting the observational window to 9 days post-fertilization, well before the maturation of the adaptive immunity. Human melanoma cells were xenotransplanted into zebrafish embryos and tracked in the presence or absence of HP-NAP. The behavior and phenotype of macrophages and the impact of their drug-induced depletion were analyzed exploiting macrophage-expressed transgenes. HP-NAP administration efficiently inhibited tumor growth and metastasis and this was accompanied by strong recruitment of macrophages with a pro-inflammatory profile at the tumor site. The depletion of macrophages almost completely abrogated the ability of HP-NAP to counteract tumor growth. Our findings highlight the pivotal role of activated macrophages in counteracting melanoma growth and support the notion that HP-NAP might become a new biological therapeutic agent for the treatment of metastatic melanomas.     

Update on optimized purification and characterization of natural milk allergens

Highly purified allergens namely cow's milk alpha-lactalbumin (ALA). (Bos d 4), beta-lactoglobulin (BLG) (Bos d 5) and casein (Bos d 8) and goat's milk casein were prepared from the raw milk from a single animal with a known genetic background. Consequently the natural isoforms are limited, constant and characterized. Purification included selective precipitations and chromatographical steps. Characterization of structure and allergenic activity assessment of milk allergens were carried out using physicochemical and immunochemical methods. Taken together data demonstrated the absence of impurities and of contamination by other milk allergens in each preparation. NMR and circular dichroism analyses confirmed the native conformation and proper folding of ALA and BLG and the expected absence of folding of bovine and caprine casein. Enzyme immuno assays confirmed the native conformation of BLG and the purity and immunoreactivity of all the proteins. The allergenic activity, e. g. the IgE binding capacity, of purified proteins was identical as that of those proteins when present in milk. The purified proteins also demonstrated the ability to provoke the degranulation of humanized rat basophilic leukaemia cells. All the data thus confirm the purity, identity, structural conformation and functionality of the prepared milk allergens.     

Modelling complex manufacturing systems using discrete event simulation

This paper presents an approach in simulating complex manufacturing systems. The approach is founded on developing several general purpose simulation generators for an assembly station, a manufacturing cell, and an inventory transfer function. These simulation generators can then be linked together to create a model of a complex manufacturing system. A typical manufacturing system is modelled using these simulation generators and the results summarized.     

Physical mapping of chromosomes VII and XV of Saccharomyces cerevisiae at 3·5 kb average resolution to allow their complete sequencing

The high resolution complete physical maps of chromosomes VII and XV were constructed to form the basis for sequencing these chromosomes as part of the European systematic sequencing programme of the yeast genome, using a unique cosmid library from strain FY1679, and an original top-down mapping strategy involving I-Sce I chromosome fragmentation. A total of 138 and 196 cosmid clones were used to construct the maps for VII and XV, respectively, forming two unique contigs that cover the entirety of chromosomes (1091 kb each), except the telomeric repeats. Colinearity of the cosmid inserts with yeast DNA was verified, and the physical maps were eventually compared with the independently generated genetic maps. © 1998 John Wiley & Sons, Ltd.