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21.
Extant literature suggests that product modularity positively and directly impacts the timeliness and frequency of new products as well as manufacturing performance, particularly flexibility. Little is known about the nature of these relationships, however, since few empirical studies have been done. Important questions remain unanswered including whether the effect of modularity on launch speed is direct or indirect, and what role other constructs might play. This study explores these issues by examining the effects of product modularity on launch speed within a holistic framework that considers the roles of product platforms and manufacturing flexibility. Drawing upon dynamic capabilities theory in the resource-based view, the model depicts product modularity as antecedent to product platforms, product platforms as antecedent to manufacturing flexibility and manufacturing flexibility as antecedent to launch speed. The model is strongly supported by an analysis of 93 manufacturers. Results reveal a positive effect of product modularity on launch speed, but it is delivered through the mediating effects of product platforms and manufacturing flexibility. In contrast to earlier work, the findings show modularity alone is an insufficient condition for the timely and frequent introduction of new products. Rather, launch speed is engendered by a ‘gestalt’ of dynamic capabilities. 相似文献
22.
J de Kanel WE Vickery B Waldner RM Monahan FX Diamond 《Canadian Metallurgical Quarterly》1998,43(3):622-625
A forensic procedure for the quantitative confirmation of lysergic acid diethylamide (LSD) and the qualitative confirmation of its metabolite, N-demethyl-LSD, in blood, serum, plasma, and urine samples is presented. The Zymark RapidTrace was used to perform fully automated solid-phase extractions of all specimen types. After extract evaporation, confirmations were performed using liquid chromatography (LC) followed by positive electrospray ionization (ESI+) mass spectrometry/mass spectrometry (MS/MS) without derivatization. Quantitation of LSD was accomplished using LSD-d3 as an internal standard. The limit of quantitation (LOQ) for LSD was 0.05 ng/mL. The limit of detection (LOD) for both LSD and N-demethyl-LSD was 0.025 ng/mL. The recovery of LSD was greater than 95% at levels of 0.1 ng/mL and 2.0 ng/mL. For LSD at 1.0 ng/mL, the within-run and between-run (different day) relative standard deviation (RSD) was 2.2% and 4.4%, respectively. 相似文献
23.
This report on the pharmaceutical industry will be published in two parts. Part I begins with a summary of the study and its conclusions. The authors then provide an overview of the characteristics of the industry and current trends in its growth and structure: production and consumption, employment, research and development, capital investment, firm and product concentration and product competition, and pricing. A discussion of international trade follows, covering intra- and inter-regional, intra-firm, and intra-industry trade. The report will continue in the next issue of the Journal (Part II) with a look at foreign direct investment, inter-firm networks, and governmental policies. 相似文献
24.
Vickery Chad D.; Sepehri Arash; Evans Clea C.; Evans Clea C.; Lee Jae Eun 《Canadian Metallurgical Quarterly》2008,53(2):171
Purpose: Explore the relationship of level and stability of self-esteem with self-reported depressive symptoms during acute inpatient stroke rehabilitation. Research Method: A consecutive sample of 79 participants was administered measures of state self-esteem and mood twice a day for 4 consecutive days. The Geriatric Depression Scale (GDS) was administered at the end of the 4 days. Self-esteem level was calculated by averaging the total self-esteem scores across the assessments, and self-esteem stability was operationalized as the standard deviation of self-esteem total scores. Mood level and stability were calculated likewise. Results: Regression analysis indicated that self-esteem stability moderated self-esteem level in predicting GDS scores, with stable lower self-esteem level associated with the most reported depressive symptoms. Unstable higher self-esteem levels were associated with more depressive symptoms than stable higher self-esteem. This interaction was demonstrated after controlling for mood level and stability, suggesting the independence of self-esteem stability from mood characteristics. Conclusion: Self-esteem stability may be an important variable in identifying individuals at risk for emotional disturbance following stroke. Further exploration of self-esteem stability correlates in this setting is warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
25.
Somatic mutations in the RET proto-oncogene are involved in the pathogenesis of an important subset (40-60%) of sporadic medullary thyroid carcinomas (MTCs) and less frequently (0-31%) in benign, sporadic phaeochromocytomas. Since limited data exist regarding the significance of somatic RET mutations in malignant phaeochromocytomas, we analysed a multicentre series of proven malignant (i.e., metastasised) phaeochromocytomas. Analogous with MTCs, where RET mutations lead to an aggressive behaviour, we hypothesised that somatic mutations would occur more frequently in malignant than in benign phaeochromocytomas. Paraffin-embedded tissue was available from 29 malignant and 27 benign phaeochromocytomas. Exons 10, 11 and 16 were analysed by non-radioactive single-strand conformation polymorphism, heteroduplex gel electrophoresis, restriction enzyme digestion and aberrant band patterns by non-isotopic sequencing. In only 1 of 29 malignant phaeochromocytomas was a mis-sense mutation found (at codon 634 of exon 11), whereas in 15% (4/27) of the benign tumours a point mutation was detected (in 3 tumours in exon 16 at codon 918 and in 1 tumour in exon 10 at codon 618). Absence of these mutations in non-tumourous DNA proved their somatic origin. Contrary to what has been reported for MTCs, oncogenic RET mutations are not associated with an aggressive tumour behaviour in sporadic phaeochromocytomas. 相似文献
26.
J Strain CR Lorenz J Bode S Garland GA Smolen DT Ta LE Vickery VC Culotta 《Canadian Metallurgical Quarterly》1998,273(47):31138-31144
Yeast deficient in the cytosolic copper/zinc superoxide dismutase (SOD1) exhibit metabolic defects indicative of oxidative damage even under non-stress conditions. To help identify the endogenous sources of this oxidative damage, we isolated mutant strains of S. cerevisiae that suppressed metabolic defects associated with loss of SOD1. Six complementation groups were isolated and three of the corresponding genes have been identified. One sod1Delta suppressor represents SSQ1 which encodes a hsp70-type molecular chaperone found in the mitochondria. A second sod1Delta suppressor gene, designated JAC1, represents a new member of the 20-kDa J-protein family of co-chaperones. Jac1p contains a mitochondrial targeting consensus sequence and may serve as the partner for Ssq1p. Homologues of Ssq1p and Jac1p are found in bacteria in close association with genes proposed to be involved in iron-sulfur protein biosynthesis. The third suppressor gene identified was NFS1. Nfs1p is homologous to cysteine desulfurase enzymes that function in iron-sulfur cluster assembly and is also predicted to be mitochondrial. Each of the suppressor mutants identified exhibited diminished rates of respiratory oxygen consumption and was found to have reduced mitochondrial aconitase and succinate dehydrogenase activities. Taken together these results suggest a role for Ssq1p, Jac1p, and Nfs1p in assembly/maturation of mitochondrial iron-sulfur proteins and that one or more of the target Fe/S proteins contribute to oxidative damage in cells lacking copper/zinc SOD. 相似文献
27.
Here we demonstrate a new microscopic method that combines atomic force microscopy (AFM) with fluorescence resonance energy transfer (FRET). This method takes advantage of the strong distance dependence in Förster energy transfer between dyes with the appropriate donor/acceptor properties to couple an optical dimension with conventional AFM. This is achieved by attaching an acceptor dye to the end of an AFM tip and exciting a sample bound donor dye through far-field illumination. Energy transfer from the excited donor to the tip immobilized acceptor dye leads to emission in the red whenever there is sufficient overlap between the two dyes. Because of the highly exponential distance dependence in this process, only those dyes located at the apex of the AFM tip, nearest the sample, interact strongly. This limited and highly specific interaction provides a mechanism for obtaining fluorescence contrast with high spatial resolution. Initial results in which 400 nm resolution is obtained through this AFM/FRET imaging technique are reported. Future modifications in the probe design are discussed to further improve both the fluorescence resolution and imaging capabilities of this new technique. 相似文献
28.
29.
Ximenynic acid inSantalum obtusifolium seed oil 总被引:2,自引:2,他引:0
J. R. Vickery F. B. Whitfield G. L. Ford B. H. Kennett 《Journal of the American Oil Chemists' Society》1984,61(5):890-891
AnalyzingSantalum obtusifolium seed oil led to the identification of 12 fatty acids; only ximenynic (71.5%) and oleic (14.3%) acids were present in substantial
amounts. Data on the mass spectrum and1H- and13C-NMR (nuclear magnetic resonance) spectra of methyl ximenynate are given. 相似文献
30.