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91.
Opitz-Kaveggia syndrome (also known as FG syndrome) is an X-linked disorder characterized by mental retardation, relative macrocephaly, hypotonia and constipation. We report here that the original family for whom the condition is named and five other families have a recurrent mutation (2881C>T, leading to R961W) in MED12 (also called TRAP230 or HOPA), a gene located at Xq13 that functions as a thyroid receptor-associated protein in the Mediator complex.  相似文献   
92.
Ethanol, 3 g/kg i.p., did not significantly alter the acute toxicity of amphetamine in the mouse. However, the urinary metabolite pattern was changed, suggesting that ethanol suppressed metabolism of the stimulant during the initial 6 h period. After 24 h, the mouse metabolized the same fraction of a given dose of amphetamine, whether it was given as amphetamine alone or amphetamine mixed with 2,3 or 4 g/kg ethanol.  相似文献   
93.
5-Methylcytosine localised in mammalian constitutive heterochromatin   总被引:26,自引:0,他引:26  
O J Miller  W Schnedl  J Allen  B F Erlanger 《Nature》1974,251(5476):636-637
  相似文献   
94.
95.
调节大豆籽粒生育的生理生态因素   总被引:1,自引:0,他引:1  
大豆籽粒是生殖生长时期植株光合产物主要存储库,鼓粒灌浆期籽粒的生长发育以及干物质积累的过程直接影响大豆的产量。因此,研究大豆籽粒的生长发育及其影响因素对提高产量至关重要。影响大豆籽粒生长发育的因素很多,从源库的改变、外界温度、光照、水分供应以及二氧化碳的浓度的影响,酶活性、内源物质含量的调节以及植物激素的调控等方面予以综述。参64。  相似文献   
96.
With time-based competition and rapid technology advancements, effective manufacturingscheduling and supply chain coordination are critical to quickly respond to changing marketconditions. These problems, however, are difficult in view of inherent complexity and variousuncertainties involved. Based on a series of results by the authors, decomposition and coordination byusing Lagrangian relaxation is identified in this paper as an effective way to control complexity anduncertainty.A manufacturing scheduling problem is first formulated within the job shop context withuncertain order arrivals, processing times, due dates, and part priorities as a separable optimizationproblem. A solution methodology that combines Lagrangian relaxation, stochastic dynamicprogramming, and heuristics is developed. Method improvements to effectively solve large problemsare also highlighted. To extend manufacturing scheduling within a factory to coordinate autonomicmembers across chains of suppliers, a decentralized supply chai  相似文献   
97.
This paper analyzes a discrete-time multiple vacations finite-buffer queueing system with batch renewal input in which inter-arrival time of batches are arbitrarily distributed.Service and vacation times are mutually independent and geometrically distributed.The server takes vacations when the system does not have any waiting jobs at a service completion epoch or a vacation completion epoch.The system is analyzed under the assumptions of late arrival system with delayed access and early arrival system.Using the supplementary variable and the imbedded Markov chain techniques, the authors obtain the queue-length distributions at pre-arrival,arbitrary and outside observer’s observation epochs for partial-batch rejection policy.The blocking probability of the first-,an arbitrary-and the last-job in a batch have been discussed.The analysis of actual waiting-time distributions measured in slots of the first-,an arbitrary- and the last-job in an accepted batch,and other performance measures along with some numerical results have also been investigated.  相似文献   
98.
This is an exploratory case study of a management issue that confronts filmmakers: how do they select locations for their films? The outcome of those decisions can have vast and immediate effects upon the profitability of a film. This is a sometimes shadowy, but significant industry with a major economic impact. For systems theory advocates, students, and explorers, this study demonstrates that investigative, immersive action research techniques can be used to explore what are otherwise hidden, somewhat cloistered business organizations and industry structures that are ordinarily closed to outsiders. The soft-system of this industry that is rooted upon trust, loyalty, alliances, relationships, and other non-financial bonds influence its decisions, and its institutional performance. While this research is focused upon a fragment of the overall film industry worldwide, and is thus limited in the universality of the propositions that subsequently emerge, this study can serve as a springboard for research into other soft systems, from which new knowledge of managerial perspectives can emerge.  相似文献   
99.
Soft systems methodology (SSM) is now 40?years old. Another decade has passed since Checkland??s thirty year retrospective on the methodology, published in 2000. It can now be described as an old methodology. But it has adapted and changed over the years and is still very much alive, although the days are long gone when it was mainly developed and practised by its founders at the University of Lancaster. Interestingly, considering that many applications of SSM over the years have been to information systems, it was developed before the age of personal computers and the Internet. The way SSM is viewed has changed over the years as it has been applied to various types of problem situation. Every use of SSM will potentially hold methodological lessons in addition to those about the situation of concern; these may include SSMs framework of ideas, processes and way of use. How is SSM going to change in the future? This will depend in part on the types of problem situation to which it is applied. This paper examines some problem situations associated with emerging technologies in the information age to which SSM has not yet been much applied. These include computer simulation and virtual reality, ubiquitous computing and the design of cities, Information Technology Service Management and the design of enterprise information architectures. Some of the different worldviews associated with these problem situations which could be explored using SSM are noted.  相似文献   
100.
Interdisciplinarity, as a concept and practice, is reviewed and related to a recent article (Romm, 1998) in this journal. Authors advocating interdisciplinarity for social research and problem solving seem to have diverse, if often largely implicit, epistemological, and other assumptions informing their proposals. Romm (1998) develops and advocates a critical and reflexive orientation for tying interdisciplinarity to action research and related endeavors. For some academicians, however, interdisciplinarity appears to be considered a relatively unproblematic pursuit of merely selecting appropriate methods. Significant issues and questions concerning interdisciplinary pursuits, particularly in academic settings, exist and are briefly explored, based on the experiences and perceptions of the author. Basic structures and processes found in fields such as action research/science and management systems often seem neglected and very much needed for interdisciplinary inquiry and knowledge construction.  相似文献   
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