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The forecasting of capacity and its utilization is particularly relevant in the aerospace industry because of long product delivery lead-times and the forward-pricing system. The objective of this paper is to develop a method for forecasting both the industry's capacity and its capacity utilization so that decision makers who must rely on this information may have policy guidance. The result shows that the aerospace industry's capacity expansion rate is closely tied to its present and recent past state of capacity utilization, and to anticipated changes in output. Output, in turn, can be predicted by using Five Year Defense Plans data and information on the cyclical nature of commercial business. Based on these findings, we were able to build an accurate model for forecasting aerospace industry capacity utilization. 相似文献
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Weiss J Pyrski M Jacobi E Bufe B Willnecker V Schick B Zizzari P Gossage SJ Greer CA Leinders-Zufall T Woods CG Wood JN Zufall F 《Nature》2011,472(7342):186-190
Loss of function of the gene SCN9A, encoding the voltage-gated sodium channel Na(v)1.7, causes a congenital inability to experience pain in humans. Here we show that Na(v)1.7 is not only necessary for pain sensation but is also an essential requirement for odour perception in both mice and humans. We examined human patients with loss-of-function mutations in SCN9A and show that they are unable to sense odours. To establish the essential role of Na(v)1.7 in odour perception, we generated conditional null mice in which Na(v)1.7 was removed from all olfactory sensory neurons. In the absence of Na(v)1.7, these neurons still produce odour-evoked action potentials but fail to initiate synaptic signalling from their axon terminals at the first synapse in the olfactory system. The mutant mice no longer display vital, odour-guided behaviours such as innate odour recognition and avoidance, short-term odour learning, and maternal pup retrieval. Our study creates a mouse model of congenital general anosmia and provides new strategies to explore the genetic basis of the human sense of smell. 相似文献
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Greer EL Maures TJ Ucar D Hauswirth AG Mancini E Lim JP Benayoun BA Shi Y Brunet A 《Nature》2011,479(7373):365-371
Chromatin modifiers regulate lifespan in several organisms, raising the question of whether changes in chromatin states in the parental generation could be incompletely reprogrammed in the next generation and thereby affect the lifespan of descendants. The histone H3 lysine 4 trimethylation (H3K4me3) complex, composed of ASH-2, WDR-5 and the histone methyltransferase SET-2, regulates Caenorhabditis elegans lifespan. Here we show that deficiencies in the H3K4me3 chromatin modifiers ASH-2, WDR-5 or SET-2 in the parental generation extend the lifespan of descendants up until the third generation. The transgenerational inheritance of lifespan extension by members of the ASH-2 complex is dependent on the H3K4me3 demethylase RBR-2, and requires the presence of a functioning germline in the descendants. Transgenerational inheritance of lifespan is specific for the H3K4me3 methylation complex and is associated with epigenetic changes in gene expression. Thus, manipulation of specific chromatin modifiers only in parents can induce an epigenetic memory of longevity in descendants. 相似文献
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Is the most profit to be had from research inspired by curiosity or by foresight of practical applications? A recent suggestion that the answer could be found by evaluating curiosity-oriented projects has proved hard to follow up. 相似文献
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F. Berthezene I. Kobayashi M. A. Greer Catherine F. Allen 《Cellular and molecular life sciences : CMLS》1973,29(5):613-615
Résumé Nous avons étudié l'effet de l'iodure 127 (10–3 et 10–4
M) sur la sécrétion de T4
*, T3
* et –I* par la thyroïde de rat, prémarquée à l'iode 131 et perfusée in situ avec du sang non radioactif contenant 12 mU de TSH/ml. Il n'a pas été noté de changement significatif dans la sécrétion de T4
* ou T3
* jusqu'à 45 min après le début de l'administration d'iodure 127, qu'il y ait ou non du méthimazole (10–3
M) dans le sang perfusé. Il y avait par contre une augmentation de la sécrétion d'-I* pendant la perfusion de 10–3
M d'ïodure, indiquant une décharge d'-I* pendant la perfusion de 10–3
M d'ïodure, indiquant une décharge d'-I* de provenance intrathyroïdienne. Cet effet est similaire à celui noté auparavant pendant le perfusion de 10–3
M de ClO
4
–
. 相似文献
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Summary Injection of 1–24 ACTH is more effective by the i.m. than i.p. route. Large doses are required to induce consistent maximal adrenal corticosterone secretion.Supported by grants from the National Institute of Arthritis, Metabolism and Digestive Diseases, National Institutes of Health, Bethesda, Maryland, USA. 相似文献