Analogy electromagnetism-acoustics: Validation and application to local impedance active control for sound absorption

An analogy between electromagnetism and acoustics is presented in 2D. The propagation of sound in presence of absorbing material is modeled using an open boundary microwave package. Validation is performed through analytical and experimental results. Application to local impedance active control for free field sound absorption is finally described

Analogy electromagnetism-acoustics: Validation and application to local impedance active control for sound absorption

An analogy between electromagnetism and acoustics is presented in 2D. The propagation of sound in presence of absorbing material is modeled using an open boundary microwave package. Validation is performed through analytical and experimental results. Application to local impedance active control for free field sound absorption is finally described

Complex mechanisms for c-fos and c-jun degradation

c-fos and c-jun proto-oncogenes have originally been found in mutated forms in murine and avian oncogenic retroviruses. They both define multigenic families of transcription factors. Both c-jun and c-fos proteins are metabolically unstable. In vivo and in vitro work by various groups suggests that multiple proteolytic machineries, including the lysosomes, the proteasome and the ubiquitous calpains, may participate in the destruction of c-fos and c-jun. The relative contribution of each pathway is far from being known and it cannot be excluded that it varies according to the cell context and/or the physiological conditions. It has been demonstrated that, in certain occurrences, the degradation of both c-fos and c-jun by the proteasome in vivo involves the ubiquitin pathway. However, the possibility that proteasomal degradation can also occur in a manner independent of the E1 enzyme of the ubiquitin cycle remains an open issue

Complex mechanisms for c-fos and c-jun degradation

c-fos and c-jun proto-oncogenes have originally been found in mutated forms in murine and avian oncogenic retroviruses. They both define multigenic families of transcription factors. Both c-jun and c-fos proteins are metabolically unstable. In vivo and in vitro work by various groups suggests that multiple proteolytic machineries, including the lysosomes, the proteasome and the ubiquitous calpains, may participate in the destruction of c-fos and c-jun. The relative contribution of each pathway is far from being known and it cannot be excluded that it varies according to the cell context and/or the physiological conditions. It has been demonstrated that, in certain occurrences, the degradation of both c-fos and c-jun by the proteasome in vivo involves the ubiquitin pathway. However, the possibility that proteasomal degradation can also occur in a manner independent of the E1 enzyme of the ubiquitin cycle remains an open issue

Genetic and non-genetic parameters related to embryo production in superovulated Large White (LW) gilts

The aim of this study was to identify genetic and non genetic factors which might affect results of embryo production of Large White (LW) cyclic gilts from data collected in one herd during 6 years. Donors (n=1060) were synchronized with a progestogen treatment and luteolysis was induced 13-15 days later by 2 injections of cloprostenol. To stimulate follicular development 800 IU eCG was then injected 24 h later, followed by 500 IU hCG 48 h later. Donors were inseminated twice; depending on the onset of oestrus, the interval between hCG treatment and first insemination (hCGAl1) was either 24 or 41 h. Embryos were collected at 5-6 days after the 1st AI by flushing uterine horns. Traits of interest were the number of corpora lutea (CL), the number of flushed embryos (FE), the number of transferable embryos (TE) and the number of unfertilized embryos CUE). The average number of TE was 18.8 +/- 9.0. The main sources of variation for CL, FE and TE were the season (P 0.89) for the maternal effect. A breeding scheme based on CL selection in response to superovulation could thus improve the number of transferable embryos

Cloning and molecular characterization of a soluble epoxide hydrolase from Aspergillus niger that is related to mammalian microsomal epoxide hydrolase.

Aspergillus niger strain LCP521 harbours a highly processive epoxide hydrolase (EH) that is of particular interest for the enantioselective bio-organic synthesis of fine chemicals. In the present work, we report the isolation of the gene and cDNA for this EH by use of inverse PCR. The gene is composed of nine exons, the first of which is apparently non-coding. The deduced protein of the A. niger EH shares significant sequence similarity with the mammalian microsomal EHs (mEH). In contrast to these, however, the protein from A. niger lacks the common N-terminal membrane anchor, in line with the fact that this enzyme is, indeed, soluble in its native environment. Recombinant expression of the isolated cDNA in Escherichia coli yielded a fully active EH with similar characteristics to the fungal enzyme. Sequence comparison with mammalian EHs suggested that Asp(192), Asp(348) and His(374) constituted the catalytic triad of the fungal EH. This was subsequently substantiated by the analysis of respective mutants constructed by site-directed mutagenesis. The presence of an aspartic acid residue in the charge-relay system of the A. niger enzyme, in contrast to a glutamic acid residue in the respective position of all mEHs analysed to date, may be one important contributor to the exceptionally high turnover number of the fungal enzyme when compared with its mammalian relatives. Recombinant expression of the enzyme in E. coli offers a versatile tool for the bio-organic chemist for the chiral synthesis of a variety of fine chemicals

Determination by echography of uterine changes around puberty in gilts and evaluation of a diagnosis of puberty

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