23 research outputs found

    A view of developing patterns of investment in AMT through empirical taxonomies: new evidence

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    In line with the theoretical premises of the research, the aim of this paper is two-fold: firstly, to determine whether there are different patterns of advanced manufacturing technology (AMT) investment behavior in the Andalusian aeronautical industry that can be associated with different technology strategies, as in other sectors and geographical areas and, secondly, to identify possible similarities or differences from previous research, such as Boyer et al. [J. Operations Manage. 14 (4) (1996) 297–313] and Jonsson [Int. J. Operations Production Manage. 20 (12) (2000) 1446–1474]. A survey of the 20 plants in the population was conducted via postal questionnaire between July 1999 and April 2001, with a structured interview being held at a later date. A cluster analysis was performed which allowed a taxonomy with three groups of plants to be established: traditionalists, designers and investors. These three groups differ from each other with regard to their AMT investments, industrial activity, size and degree of integration. Differences between the groups in company performance cannot be appreciated. Although the results apparently seem to back up most of the findings of previous works biased to larger companies, they do bring certain aspects into question regarding the explanation for the way the groups are formed. The three critical factors which determine AMT investment in the sector are the company’s being of a certain minimum size, undergoing a period of expansion, and type of activity.This research has been partially funded by the CICYT (Spanish Inter-Ministerial Commission for Science and Technology) through project number PB1869, and by the Andalusian Regional Government.Publicad

    A Novel and Simple Procedure for the Enantiospecific Synthesis of Bridgehead Norbornane Thioethers and Thiocyanates.

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    An easy three-step route for the enantiospecific synthesis of novel 1-norbornyl thioethers and thiocyanates from readily available natural fenchone and camphor is described. The key step of the synthetic route is the nucleophilic substitution over the sulfenyl sulfur atom of the intermediate thiotriflates by the corresponding C-nucleophiles

    TGF beta 3 induced chondroitin sulphate proteoglycan mediates palatal shelf adhesion

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    AbstractIn mammals, the adhesion and fusion of the palatal shelves are essential mechanisms in the development of the secondary palate. Failure of any of these processes leads to the formation of cleft palate. The mechanisms underlying palatal shelf adhesion are poorly understood, although the presence of filopodia on the apical surfaces of the superficial medial edge epithelial (MEE) cells seems to play an important role in the adhesion of the opposing MEE. We demonstrate here the appearance of chondroitin sulphate proteoglycan (CSPG) on the apical surface of MEE cells only immediately prior to contact between the palatal shelves. This apical CSPG has a functional role in palatal shelf adhesion, as either the alteration of CSPG synthesis by β-d-Xyloside or its specific digestion by chondroitinase AC strikingly alters the in vitro adhesion of palatal shelves. We also demonstrate the absence of this apical CSPG in the clefted palates of transforming growth factor beta 3 (TGF-β3) null mutant mice, and its induction, together with palatal shelf adhesion, when TGF-β3 is added to TGF-β3 null mutant palatal shelves in culture. When chick palatal shelves (that do not adherein vivo nor express TGF-β3, nor CSPG in the MEE) are cultured in vitro, they do not express CSPG and partially adhere, but when TGF-β3 is added to the media, they express CSPG and their adhesion increases strikingly. We therefore conclude that the expression of CSPG on the apical surface of MEE cells is a key factor in palatal shelf adhesion and that this expression is regulated by TGF-β3
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