F.H.A. Janszen

Innovation in the construction industry: the dominant role of the environment

In this research paper the innovative and strategic behaviour of the construction industry and the companies within that sector are analysed. In other sectors, but in particular for builders, a clear relationship with their environment is shown. When these external circumstances are positive the industry is apparently very capable of innovation. Recently we have noticed increasing environmental turbulence, which will have an enormous impact on management. Companies in the construction industry will have to compete in a more extrovert and market-driven way and they will have to reconsider their capabilities. Specialization and diversification on various subjects are probably the most important strategic choices. Innovation creates possibilities of achieving competitive advantage, but only when managed properly. The existing ‘engineers paradigm’ in the construction industry will be an important obstacle, but at the end of this process companies will increasingly have the character of what Chandler refers to...

A Leydig cell tumour: a model for the study of lutropin action.

The properties of cells isolated from a Leydig cell tumour have been compared with normal rat testis Leydig cells. These cells were found to be similar in the following respects: 1. Lutropin-stimulated cyclic AMP and testosterone production. 2. Lutropin-activated protein kinase activity followed by phosphorylation of endogenous proteins of mol. wts. 57,000and 14,000. 3. Parallel lutropin dose vs. response curves for phosphorylation of the endogenous proteins and for testosterone production. 4. Two forms of isoenzyme, cyclic AMP dependent protein kinase, present. They differed mainly with respect to the lutropin-stimulated testosterone production, which was much lower in the tumour cells compared with the normal adult testis Leydig cells (4.6 +/- 1.1 and 114 +/- 16 ng testosterone/10(6) cells per 2 h, respectively). However, the lutropin-stimulated steroid production in the tumour cells was quantitatively comparable with the normal rat Leydig cell when the metabolism of pregnenolone in intact cells and mitochondria was inhibited by addition of SU-10603 and/or cyanoketone. It is concluded that the Leydig cell tumour used in this study can be used to investigate certain aspects of lutropin action where large quantities of cells are required.

A dynamic analysis of the relations between the structure and the process of National Systems of Innovation using computer simulation; the case of the Dutch biotechnological sector

Abstract In this study, the relationship between regional attributes and the generation and exploitation of technology was investigated. The study consists of two parts, an empirical study of the Dutch biotechnology sector and a computer modeling part. In this computer model, based upon system dynamics, postulated mechanisms of the innovation process in the Dutch biotechnology sector were modeled and the results of these simulations were compared with the results obtained from the empirical research. From this study, it can be concluded that computer modeling may increase our insight into the dynamics of the innovation process and may help in formulating research questions for future research.

Evidence for the involvement of lutropin-independent RNA synthesis in Leydig cell steroidogenesis.

The effect of incubating purified Leydig cells in Eagles medium and the subsequent effect of the RNA synthesis inhibitors, actinomycin D and cordycepin, on lutropin-stimulated testosterone synthesis have been investigated. The inhibiting effect was found to be inversely related to the time of preincubation; with cells preincubated for 0, 1, 2 and 3 h with Eagles medium only, followed by 2-h incubation with lutropin with and without actinomycin D, testosterone synthesis was inhibited by 37 +/- 4, 31 +/- 3, 18 +/- 4 and 14 +/- 3% respectively (means +/- s.e.m., n = 5). In cells that had been preincubated for 3 h there was no significant effect of actinomycin D on testosterone synthesis during the first hour of incubation with lutropin. Thereafter the inhibition increased with time reaching a maximum of 30% after 5 h. The effects of preincubation were not due to endogenous lutropin in the Leydig cells because cells isolated from hypophysectomized rats gave similar results. The inhibition of [3H]uridine incorporation into the Leydig cell RNA was 80 +/- 1% with 8 microgram/ml actinomycin D. Increasing the concentration of this inhibitor to 80 microgram/ml did not significantly increase the inhibition of [3H]uridine incorporation or lutropin-stimulated steroidogenesis in preincubated and non-preincubated cells. With cordycepin the inhibition of both RNA synthesis and lutropin-stimulated testosterone synthesis in non-preincubated cells were the same; with 25.1--251 microgram/ml approx. 30--70% resp. With preincubated cells (3 h), 0--50% inhibition of testosterone synthesis was obtained respectively. The inhibitory effect of actinomycin D oimilar to that obtained with lutropin. These observations suggest that during preincubation and independently of lutropin, synthesis of intermediates, including RNAs required for stimulation of steroidogenesis, takes place and that subsequent stimulation of steroidogenesis by lutropin occurs without further de novo RNA synthesis. These results provide evidence for a permissive role of specific RNA and protein synthesis in the action of lutropin on testosterone synthesis in the Leydig cell.

LH induction of a specific protein (LH-IP) in rat testis leydig cells

The available evidence suggests that LH stimulation of testosterone production in rat testis Leydig cells involves protein(s) with a short half life. This evidence is based on the effects of inhibitors of protein and RNA synthesis on LH stimulated testosterone production [l-3] , particularly the rapid effect of cycloheximide, which causes a decrease in testosterone synthesis following first order kinetics with a half life of 13 min [4]. Recent work in our laboratory has shown that two proteins which are synthesized in rat testis Leydig cells and which can be detected using polyacrylamide gel electrophoresis, may be impottant in the regulation of testosterone production by LH; one of these proteins has a short half life (about 11 min) and is present in the particulate fraction of the Leydig cell, but is not under the influence of LH; the other protein (referred to as LH-IP, LH-induced protein) can be detected 2 h after the addition of LH to Leydig cells and has a half life longer than 30 min [5]. We now wish to report that the second protein (LH-IP) can be induced by LH or dibutyryl-CAMP but not by testosterone or follicle stimulating hormone (FSH). Dose response studies have also shown that the induction of LH-IP and the stimulation of testosterone production require approximately the same concentrations of LH. Incubation of the Leydig cells with actinomycin D prevented the induction of LH-IP by LH.

The testis: Biochemical actions of trophic hormones and steroids on steroid production and spermatogenesis

Abstract The present paper summarizes recent new information on steroid production and spermatogenesis in the rat testis, with respect to: 1. The cellular and subcellular localization of testicular steroid production. 2. Biochemical factors which appear to be related to the effect of trophic homones on testicular steroid production. 3. Some biochemical observations on Sertoli cells and germinal cells in the seminiferous tubules and relationships with steroid hormones.

Role of cyclic amp in steroidogenesis in leydig cells: ‘Discrepancies’ between effects of luteinizing hormone and cholera toxin

The mechanisms by which luteinizing hormone (LH) controls steroidogenesis in testis Leydig cells are not well defined. The available evidence suggests that in similarity with the adrenal gland, activation of adenylate cyclase [l-3], protein kinase [3,4] and protein synthesis [5-71 are involved. However, in contrast to the adrenal gland, steroidogenesis in trophic hormone (LH, hCG)-stimulated Leydig cells has been shown: (1) To proceed more slowly (20-30 min is required before increases in steroidogenesis can be detected [2,8,9] (compared with 24 s 3 min in the adrenal gland [ 1 O] ). (2) To be maximal without increases in cyclic AMP being detectable [ I] . These data suggest that additional or different mechanisms not involving cyclic AMP may be operating in the Leydig cell. In the present study the kinetics of cyclic AMP and testosterone production in LH-stimulated Leydig cells have been reinvestigated and compared with the effects of cholera toxin. The latter has previously been shown to mimic the action of hormones at their target cells through stimulation of cyclic AMP production [l l-l 51 and thus is a useful tool in elucidating the role of this nucleotide in hormone action. It has been found that by preincubating Leydig cells before addition of LH a rapid increase in testos-

Effect of cofactors and luteinizing hormone on testosterone production by rat testis preparations.

Abstract The aim of the present study was to investigate the possible cause of reported differences in testosterone production by rat testis preparations in vitro . These differences appear to reflect differences in tissue preparations and in incubation conditions, rather than differences in the steroidogenic potential of the tissue. In vitro production of testosterone by rat testis preparations was shown to be stimulated by the addition to the incubation medium of calcium and magnesium ions, succinate and a NADPH regenerating system. This effect was seen with intact and homogenized preparations of both total testis tissue and isolated interstitial tissue and with isolate testicular cell suspensions enriched in Leydig cells. Testosterone production in homogenates of seminiferous tubules was very low when compared with interstitial tissue and was not stimulated by the addition of cofactors. Luteinizing hormone (LH) stimulated testosterone production in testicular cell suspension. The effects of cofactors and of LH on testosterone production in these suspensions were not additive. On the assumption that LH would act on intact cells only and that NADPH would not enter intact cells, a comparison was made of the effect of cofactors on cell suspensions before and after disruption of the cells. It was not possible, however, to calculate the amount of damaged cells in testicular cell suspension from the response to incubation with cofactors.

Innovation and the materials revolution

Abstract This article deals with the present scientific revolution in materials engineering, the resulting inter-material competition and the effects on more traditional material suppliers, such as the steel industry. The changing rules of competition in the materials arena are discussed and the key forces behind this trend are identified. A theoretical framework is provided, consisting of negative and reinforcing feedback loops that act as drivers behind future industry change. It is argued, on the basis of empirical support, that corporate innovation is subjected to a dynamic set of (f)actors in todays business environment. The management of R&D will have to address the total dynamic system in order to ensure future effectiveness.

Business model innovation for entrepreneurs

Innovation is in limelight not only in the western world, but also in emerging markets. In the backdrop of this fertile environment, facilitating firms with building innovation capability is seen as a necessity. A structured approach to innovation management, then should extend beyond, for creating new business models in the competitive arena. This may be brought to practitioners, and students at business schools alike, in order to emphasize that this relatively new phenomenon is far too important to postpone. A survey conducted with business schools in India has shown that they are far behind not only in taking up innovation management as a major management discipline, but also advancing further to introduce business innovation concept especially in their courses on entrepreneurship.