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First Challenge (first + challenge)
Selected AbstractsParallel transmit and receive technology in high-field magnetic resonance neuroimagingINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2010Andrew G. Webb Abstract The major radiofrequency engineering challenges of high-field MR neuroimaging are as follows: (1) to produce a strong, homogeneous transmit B1 field, while remaining within regulatory guidelines for tissue power deposition and (2) to receive the signal with the maximum signal-to-noise and the greatest flexibility in terms of utilizing the benefits of parallel imaging. Borrowing from developments in electromagnetic hyperthermia, the first challenge has been met by the use of transmit arrays, in which the input power to each element of the array can be varied in terms of magnitude and phase. Optimization of these parameters, as well as the form of the applied RF pulse, leads to very homogeneous B1 fields throughout the brain. The design of large receive arrays, using impedance-mismatched preamplifiers and geometrical overlap for interelement isolation, has resulted in significant sensitivity improvements as well as large acceleration factors in parallel imaging. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 2,13, 2010 [source] Social Security in Rwanda: Overcoming IndifferenceINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 3-4 2003François-Xavier Ngarambe The current social security system in Rwanda, set up in 1962, has until recently been viewed with indifference by most Rwandans. This is because employees in the formal sense, who are the ones concerned by the pension and occupational risk branches, represent only a tiny minority of the population, attempts to provide medical cover for the population are still in their infancy, and in a context where unemployment is the rule and work the exception, the risk of unemployment is uninsurable. Faced with this situation the first challenge was to increase people's awareness of the problem by launching a debate in which social security was seen as part of efforts to combat poverty and underdevelopment. The greater awareness which this produced has enabled us to introduce a plan which we hope, on the basis of the first results, will lead to better things in future. Fundamental changes have just been made to the pension scheme, the management institution has been restructured and modernized, and efforts in the field of healthcare are producing their first fruits. Perhaps now, at long last, after years of indifference and inertia, a new day is dawning for social security in Rwanda! [source] Repeatability of measurements of the initial distribution volume of glucose in haemodynamically stable patientsJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 4 2004B. O. Rose MD Summary Aims:, The initial distribution volume of glucose (IDVG) has been proposed to provide a useful tool to estimate the central extracellular fluid volume. The purpose of this study was to determine the repetition interval of two consecutive measurements in haemodynamically stable patients without presence of recent changes in fluid status. Methods:, Twenty-nine patients admitted to the general intensive care unit of the University of Hirosaki Hospital were entered into this study. After achieving a haemodynamically stable state in each patient regardless of an infusion of vasoactive drugs, two glucose challenges at an interval of either 30 or 60 min, were carried out to calculate the IDVG. The IDVG was calculated using a one-compartment model after intravenous administration of glucose (5 g) followed by serial arterial blood sampling. Results:, Although plasma glucose levels immediately before the second glucose challenge in either group were increased compared with those of the first challenge (P < 0·001, respectively), the bias of the IDVG measurements was 0·08 ± 0·32 L (SD) for the 30-min group and ,0·19 ± 0·28 L for the 60-min group. Conclusions:, Our results indicate that IDVG determinations can be reliably repeated within a minimum interval of 30 min. [source] Rhesus monkey model for Leishmania major transmitted by Phlebotomus papatasi sandfly bitesMEDICAL AND VETERINARY ENTOMOLOGY, Issue 1 2001R. J. Probst Summary Leishmaniasis research needs a near-human model for investigations of natural infection processes, immunological responses and evaluation of treatments. Therefore, we developed a reproducible system using Leishmania major Yakimoff & Schokhor (Trypanosomatidae: Kinetoplastida), the cause of Old World zoonotic cutaneous leishmaniasis (ZCL), transmitted to rhesus monkeys Macaca mulatta (Zimmerman) (Primates: Cercopithecidae) by sandfly bites of experimentally infected Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae). Eight monkeys of presumed Indian origin (Leishmania naïve) were exposed to bites of female sandflies that had been infected with L. major by membrane-feeding on human blood seeded with amastigotes isolated from hamster footpad lesions. Infection rates of membrane-fed sandflies averaged >,85% seven days after the infective feed, with uniformly high numbers of promastigotes in the stomodaeal valve region of the sandfly gut. Nodules and ulcerating dermal lesions developed on 7/8 monkeys 2,4 weeks post-bite and persisted for 3,7 months. Monkeys also developed satellite lesions beyond the area of sandfly bites on the head, but not on the chest. Three re-challenged monkeys developed lesions that healed faster than lesions from their primary challenges. After infection, monkeys developed delayed type hypersensitivity (DTH) responses to a panel of Leishmania skin test antigens (LSTA) and, when tested by ELISA and IFA, showed significant post-infection antibody titres which typically rose for ,170 days and then gradually receded during the next 100 days following the first challenge. After the second challenge, antibody titres spiked higher within ,50 days and receded more rapidly. In contrast, four rhesus macaques of Chinese origin developed no lesions following infected sandfly bites, although they raised antibodies and LSTA reactions, indicating subclinical infection. [source] Integrating art as a trans-boundary element in a radical innovation frameworkR & D MANAGEMENT, Issue 1 2010Christian Stüer Companies have learned that radical innovations (RIs) are a prerequisite to grow organically. However, companies struggle to identify and introduce RIs, as their inherent high uncertainties and novelty challenge established organisations and management routines. To address the first challenge, companies need to take a holistic approach and design a trans-boundary environment of creativity, trans-disciplinary and entrepreneurial spirit. This environment attracts and retains visionary people, fosters generation of new opportunities and cultivates adaptability. By adapting evaluation metrics for RI, setting up flexible processes, and promoting trans-disciplinary exchange, the second challenge can be addressed. Increased research has concentrated on several aspects of RI lately, but so far a combining framework is missing. Our paper bridges this gap by developing an improved theoretical framework, enhancing the existing literature and introducing art as a method to advance trans-disciplinary interchange. In a case-study approach, we have applied our framework to the research and development department of Vodafone Research and Development, Germany, as they integrate art methodically in their research and development process. Analysing their RI capabilities, we identify the trans-disciplinary exchange with artists as a novel initiator and driver of RI, which has not yet been adequately considered. [source] | ||||||||||