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Variety Of Changes (variety + of_change)
Selected AbstractsThe Changing Power of ,Explanations': Directors, Academics and Their Sensemaking from 1989 to 2000JOURNAL OF MANAGEMENT STUDIES, Issue 7 2002Annie Pye This paper is based on empirical research conducted with directors in large UK organizations, first in 1987,89, and again in 1998,2000. While the time frame has changed, the focus of the inquiry has remained constant , how do you ,run' a large organization , and data gathered reflect significant changes over time as to how the question is answered. This paper addresses one particular aspect of this complex material: the changing power of practitioner and academic explanations across the decade, highlighted by comparing and contrasting this data and its analysis over time. The paper illustrates a surprising degree of consistency (in contrast to 1987,89 findings) in practitioners' contemporary explanations of their organizing: all talk of strategic focus, shareholder value and corporate governance, phrases previously never mentioned. This reflects a variety of changes across the decade, including an important concentration of power amongst investors. As well as the methodological implications of ,repeating' this study, the changing power of academics' explanations ,on' organization is also discussed as conceptual frameworks gain and lose their resonance with the times. The paper concludes that sensemaking (Weick, 1995) offers the most appropriate perspective by which such shifts in the power of explanations may best be appreciated. [source] Stage-dependent Dishevelled-1 expression during mouse spermatogenesis suggests a role in regulating spermatid morphological changesMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 6 2006Pengpeng Ma Abstract Dishevelled (Dsh in Drosophila or DVL in mice) is a member of the highly conserved Wg/Wnt signaling pathway, which regulates important processes such as cell proliferation, polarity, and specification of cell fate. Three orthologous genes of Dishevelled (Dvl-1, Dvl-2, and Dvl-3) have been found in both humans and mice. They play pivotal roles in regulating cell morphology and a variety of changes in cell behaviors. In the present study, we show that the expression of Dvl-1 is stage-dependent during mouse spermatogenesis, although Dvl-2 and Dvl-3 show relative consistent expression. The expression of Dvl-1 mRNA first appears in pachytene spermatocytes, increases in round and elongating spermatids, and then turns to an undetectable level in mature sperm cells. Analyses of immunohistochemistry and immunofluorescence staining show that DVL-1 is present diffusely in the cytoplasm of pachytene spermatocytes and exhibits mainly a vesicular pattern and perinuclear distribution and a weak diffusely cytoplasmic signal in round and elongating spermatids. The vesicular pattern of DVL-1 has been observed by previous studies in somatic cells, and suggested to play roles in signal transduction. Immunoprecipitation experiments show that DVL-1 coimmunprecipitates with spermatogenic cells ,-actin rather than ,-tubulin. These results indicate that DVL-1 may be involved in spermatid morphological changes during mouse spermiogenesis through mediating signal transduction and/or regulating actin cytoskeleton organization. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source] Nail Matrix Arrest Following Hand-Foot-Mouth Disease: A Report of Five ChildrenPEDIATRIC DERMATOLOGY, Issue 1 2000Gina C. Clementz B.S. Nail matrix arrest has been associated with a variety of drug exposures and systemic illnesses, including infections, and may result in a variety of changes, including transverse ridging (Beau's lines) and nail shedding (onychomadesis). The association of HFMD with Beau's lines and onychomadesis has not been reported previously. Five children, ages 22 months,4 years, presented with Beau's lines and/or onychomadesis following physician-diagnosed HFMD by 3,8 weeks. Three of the five patients experienced fever with HFMD, and none had a history of nail trauma, periungual dermatitis, periungual vesicular lesions, or a significant medication intake history. All patients experienced HFMD within 4 weeks of one another, and all resided in the suburbs of the Chicago metropolitan area. In all patients the nail changes were temporary with spontaneous normal regrowth. The mechanism of the nail matrix arrest is unclear, but the timing and geographic clustering of the patients suggests an epidemic caused by the same viral strain. [source] The Effect of Cook-Off on the Bulk Permeability of a Plastic Bonded ExplosivePROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 5 2006Guillermo Terrones Abstract Plastic bonded explosives when exposed to prolonged heating environments undergo a variety of changes that affect their bulk chemical, thermophysical, and mechanical properties. During slow heating conditions, referred to as cook-off, the thermal behavior of the polymeric binder plays an important role in the transformations of these composite energetic materials. The recently introduced Darcian flow hypothesis for PBX-9501 implies that, during preignition, temperature gradients will lead to pressure gradients which in turn will drive convection of decomposition gases throughout the explosive, thus affecting ignition time and location. Here, we focus on the cook-off behavior of PBX-9501 and investigate its effects on bulk permeability to gases produced as a result of thermal decomposition. The concept of Darcian convection through porous media is defined and illustrated in detail by the derivation of the governing equations for a permeameter. Based on a systematic analysis involving: 1) our current understanding about binder behavior as a function of temperature, 2) the physics of the gas permeameter apparatus, 3) the concept of liquid drainage by gas, and 4) the experimental record of four permeameter experiments with cooked PBX-9501, we conclude that samples heated up to 186,°C were not permeable in the Darcy-flow sense. [source] SKELETAL MUSCLE FUNCTION: ROLE OF IONIC CHANGES IN FATIGUE, DAMAGE AND DISEASECLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 8 2004DG Allen SUMMARY 1.,Repeated activity of skeletal muscle causes a variety of changes in its properties: muscles become weaker with intense use (fatigue), may feel sore and weak after repeated contractions involving stretch and can degenerate in some disease conditions. The present review considers the role of early ionic changes in the development of each of these conditions. 2.,Single fibre preparations of mouse muscle were used to measure ionic changes following activity induced changes in function. Single fibres were dissected with intact tendons and stimulated to produce force. Fluorescent indicators were microinjected into the fibres to allow simultaneous ionic measurements with determination of mechanical performance. 3.,One theory to explain muscle fatigue is that fatigue is caused by the accumulation of lactic acid, producing an intracellular acidosis that inhibits the myofibrillar proteins. In contrast, we found that during repeated tetani there was little or no pH change, but that failure of calcium release was a major contributor to fatigue. Currently, it is proposed that precipitation of calcium and phosphate in the sarcoplasmic reticulum contributes to the failure of calcium release. 4.,Muscles can be used to shorten and produce force or they can be used to de-accelerate loads (stretched or eccentric contractions). One day after intense exercise involving stretched contractions, muscles are weak, sore and tender, and this damage can take a week to recover. In this condition, sarcomeres are disorganized and there are increases in resting intracellular Ca2+ and Na+. Recently, we demonstrated that the elevation of Na+ occurs through a stretch-activated channel that can be blocked by either gadolinium or streptomycin. Preventing the increase in [Na+]i with gadolinium also prevented part of the muscle weakness after stretched contractions. 5.,Duchenne muscular dystrophy is a lethal degenerative disease of muscles in which the protein dystrophin is absent. Dystrophic muscles are more susceptible to stretch-induced muscle damage and the stretch-activated channel seems to be one pathway for the increases in intracellular Ca2+ and Na+ that are a feature of this disease. We have shown recently that blockers of the stretch-activated channel can minimize some of the short-term damage in muscles from the mdx mouse, which also lacks dystrophin. Currently, we are testing whether blockers of the stretch-activated channels given systemically to mdx mice can protect against some features of the disease. [source] | ||||||||||