4,258 research outputs found

    Innovation in services: corporate culture and investment banking

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    The article discusses service innovation in the investment banking industry. Service industry innovations differ from innovations in industries that produce physical products because they rarely have intellectual property and patent protections. However, investment banking services are typically a series of interrelated businesses such as consulting, wealth management and accounting, and innovations require a business wide coordinated approach. The authors argue that a strong corporate culture can support rather than hinder innovation. The creation of such a culture requires strong leadership and an emphasis on innovation in hiring and promotions

    Late Quaternary climatic changes revealed by luminescence dating, mineral magnetism and diffuse reflectance spectroscopy of river terrace palaeosols: a new form of geoproxy data for the southern African interior

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    AbstractThe nature, spatial patterns and forcing mechanisms of Quaternary climatic changes across southern Africa remain unresolved and contentious, principally due to the scarcity of continuous and robustly-dated proxy records. We present what we interpret to be a broadly continuous record of late Quaternary climatic change based on optically stimulated luminescence (OSL) dating, and mineral magnetic and diffuse reflectance spectroscopy (DRS) analyses of stacked palaeosols within an overbank alluvial succession along the Modder River, central South Africa. The OSL ages indicate that alluvial sedimentation occurred at a fairly steady rate, averaging ∼0.15 mm/yr from at least 44 ka until ∼0.83 ka. This suggests that the palaeosols are accretionary, having formed contemporaneously with sedimentation. Climate is identified as the key soil-forming factor controlling the intensity of pedogenesis and is reflected in the changing concentration of pedogenic ferrimagnetic minerals (magnetite/maghemite) of single domain and superparamagnetic dimensions, and by variations in the amount of hematite compared to goethite. These data indicate that the climate was generally dry (rainfall ∼200–400 mm/yr) from ∼46 to 32 ka, except for a brief peak in humidity at ∼42 ka. There was then a period of greater humidity (rainfall ∼400–600 mm/yr) from ∼32 to 28 ka, possibly reflecting enhanced moisture supply from the Atlantic Ocean associated with the equatorward migration and intensification of westerly storm tracks. Although the precise mechanism remains unresolved, this climatic change may have been linked to an obliquity minimum at ∼29 ka. After ∼28 ka, the climate became progressively cooler and drier, especially between ∼18 and 15.5 ka when rainfall was as low as ∼100–200 mm/yr. Temperatures and rainfall then increased from ∼15.5 ka onwards, with the latter possibly linked to rising sea-surface temperatures in the SW Indian Ocean and enhanced moisture supply from easterly circulation. At ∼0.83 ka, a time corresponding with part of the Medieval Climatic Anomaly (MCA, ∼900–1300 AD), rainfall reached ∼600–700 mm/yr and was higher than at present (∼400–500 mm/yr). Fluvial landforms have previously been overlooked as a source of palaeoenvironmental information in southern Africa, but this study clearly demonstrates the potential to extract robust palaeoenvironmental data from alluvial-palaeosol successions in the arid to semi-arid interior where other forms of proxy record are scarce

    Hypercalcemia Caused by Metastatic Adamantinoma: Response to Radiotherapy

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    Purpose. To describe successful palliation of a patient with metastatic adamantinoma presenting with lung metastases and hypercalcemia resulting from a parathormone-like substance released from the tumor

    Understanding the dynamics of cellular responsiveness to modifications of metabolic substrates in perifusion

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    A novel microperifusion system with capabilities for continuous, real-time, potentiometric monitoring of extracellular hydrogen ion concentration has been used to define the response of HeLa cells to abrupt changes in extracellular energy sources or introduction of an inhibitor of glycolysis. Glycolytic inhibition, induced by removal of glucose or introduction of iodoacetate, each led to a rapid, continuous decrease in acid release. The response to iodoacetate took longer than removal of glucose, perhaps due to the time required for binding and activation. Once inhibition began, however, the rate of change was greater than following glucose removal. Conversely, recovery time following iodoacetate inhibition was much slower than with glucose removal. Unlike the response to short-term glucose depletion, a second pulse of iodoacetate resulted in a faster response followed by an even longer recovery time. The response to switching between glucose and glutamine began almost without evident delay. The response patterns revealed that HeLa cells prefer glutamine to glucose, but, in the presence of both energy sources, some glucose continues to be used. In summary, these results indicate that continuous, real-time monitoring of the kinetics of hydrogen-ion release can be used to gain new insights into the dynamics of cellular response to perturbations of extracellular energy sources. © 1994 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49889/1/1041600103_ftp.pd

    Electrochemical behaviour of steel reinforced concrete during accelerated corrosion testing

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    Corrosion of reinforcing steel presents a major durability issue worldwide and is the focus of much research activity. The long time periods involved in replicating reinforcement corrosion within laboratories has resulted in a number of accelerated test methods being developed. The basis of this research presented in this paper was to examine the impressed current technique often used to induce reinforcement corrosion. The suitability of the technique to model chloride induced corrosion was investigated by examining the electrochemical nature of the test method. Corrosion was induced in prisms of differing characteristic strengths and cover thicknesses by applying a current for between 3 and 17 days. The gravimetrical and theoretical mass losses are compared and a modified expression based on Faraday’s law relating the electrical current to the mass loss is also proposed which accounts for the localised nature of chloride-induced corrosion. It was found that the technique is a suitable method to simulate reinforcement corrosion

    Observations of the relationship between sprite morphology and in-cloud lightning processes

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    [1] During a thunderstorm on 23 July 2003, 15 sprites were captured by a LLTV camera mounted at the observatory on Pic du Midi in the French Pyrénées. Simultaneous observations of cloud-to-ground (CG) and intracloud (IC) lightning activity from two independent lightning detection systems and a broadband ELF/VLF receiver allow a detailed study of the relationship between electrical activity in a thunderstorm and the sprites generated in the mesosphere above. Results suggest that positive CG and IC lightning differ for the two types of sprites most frequently observed, the carrot- and column-shaped sprites. Column sprites occur after a short delay (<30 ms) from the causative +CG and are associated with little VHF activity, suggesting no direct IC action on the charge transfer process. On the other hand, carrot sprites are delayed up to about 200 ms relative to their causative +CG stroke and are accompanied by a burst of VHF activity starting 25–75 ms before the CG stroke. While column sprites associate with short-lasting (less than 30 ms) ELF/VLF sferics, carrot sprites associate with bursts of sferics initiating at the time of the causative +CG discharge and persisting for 50 to 250 ms, indicating extensive in-cloud activity. One carrot event was found to be preceded by vigorous IC activity and a strong, long-lived cluster of ELF/VLF sferics but lacking a +CG. The observations of ELF/VLF sferic clusters associated with lightning and sprites form the basis for a discussion of the reliability of lightning detection systems based on VHF interferometry.Peer ReviewedPostprint (published version

    Comparison of paired quartz OSL and feldspar post-IR IRSL dose distributions in poorly bleached fluvial sediments from South Africa

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    AbstractA comparative study using quartz optically stimulated luminescence (OSL) and feldspar post-infrared infrared stimulated luminescence (post-IR IRSL) was undertaken on Quaternary fluvial sediments from an unnamed tributary of the Moopetsi River in South Africa. The aim is to assess whether the post-IR IRSL signal can be used to date incompletely bleached sediments. Several post-IR IRSL signals using varying stimulation and preheat temperatures were investigated; of these the post-IR IRSL225 signal was deemed most appropriate for dating because it bleached most rapidly. The feldspar post-IR IRSL225 equivalent dose (De) values from this site are consistently larger than those from quartz OSL, probably due to differences in the bleaching characteristics of the two signals. Additionally, the post-IR IRSL225 De values within a sample showed less variation in precision than the quartz De data, possibly due to greater averaging between grains in the feldspar small aliquots. The agreement between ages based on the OSL and post-IR IRSL225 signals was better for younger samples (<20 ka) than for older ones (>50 ka); the cause of this variation is unclear
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