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111.
A procedure for determining an arbitrary distribution of activation energies (E) and attempt-to-escape frequencies (s) from overlapping contributions to thermoluminescence (TL) or thermally stimulated conductivity (TSC) is described. For the case of no retrapping, i.e. first order kinetics, the glow curve can be described by a two-dimensional Fredholm equation representing a superposition of Randall-Wilkins first-order peak shapes. The solution to this equation gives the distribution of trapping energies and attempt-to-escape-frequency factors necessary to obtain the TL or TSC peak shape. Analysis of simulated TL/TSC data for trap distributions distributed in both E and s demonstrates that the arbitrary E and s values can be determined from the solution of the Fredholm equation. The procedure is demonstrated for experimental TSC data from gamma-irradiated Al2O3:C. 相似文献
112.
Tennen Howard; Affleck Glenn; Coyne James C.; Larsen Randy J.; DeLongis Anita 《Canadian Metallurgical Quarterly》2006,11(1):112
The authors applaud A. S. Green, E. Rafaeli, N. Bolger, P. E. Shrout, and H. T. Reis's (2006) response to one-sided comparisons of paper versus electronic (plastic) diary methods (see record 2006-03820-006) and hope that it will stimulate more balanced considerations of the issues involved. The authors begin by highlighting areas of agreement and disagreement with Green et al. The authors review briefly the broader literature that has compared paper and plastic diaries, noting how recent comparisons have relied on study designs and methods that favor investigators' allegiances. The authors note some sorely needed data for the evaluation of the implications of paper versus plastic for the internal and external validity of research. To facilitate evaluation of the existing literature and assist in the design of future studies, the authors offer a balanced comparison of paper and electronic diary methods across a range of applications. Finally, the authors propose 2 study designs that offer fair comparisons of paper and plastic diary methods. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
113.
The Capability Maturity Model for software has become a major force in software development process improvement. We looked at the role of process improvement in the context of a small organization. Although the Capability Maturity Model integration is replacing the CMM, we focused on the older CMM. We had to look at more than which CMM key process areas apply to small businesses. Our overall goal was to institute good software development practices, we used the language of the CMM to gain the management's cooperation. Applying these practices is essential to managing growth, yet undertaking this effort without prior experience could impede a small company's innovative nature. This case study's purpose was to investigate the success factors of a software process improvement effort for a small software development organization. 相似文献
114.
In the period 1988–1997 a series of 1462 patients aged 15 years or older with non-occupational fall injuries from ladders or scaffolds were studied. We registered 1402 ladder falls and 60 scaffold falls. The mean age was 50 years, and 1052 were males. The mean annual incidence rate was 1.18 per 1000 inhabitants/year for males and 0.41 per 1000 inhabitants/year for females. A rise in the annual incidence rates with increasing age were observed for both males and females, whereas no trend in the annual incidence rates for each of the ten years studied were observed. About 1/5 of the patients were hospitalized with a median number of 7 days. Two patients died following the injury. Half of the registered injuries were contusions or sprains, whereas about 1/3 were fractures or dislocations. The extremities were most commonly injured as 36% of the injuries were located to the lower extremities and 33% to the upper extremities. The forearm was most commonly fractured or dislocated, whereas the ankle joint was most commonly sprained or contused. 相似文献
115.
A Haaf L LeClaire G Roberts HM Kent TM Roberts M Stewart D Neuhaus 《Canadian Metallurgical Quarterly》1998,284(5):1611-1624
The major sperm protein (MSP) of Ascaris suum mediates amoeboid motility by forming an extensive intermeshed system of cytoskeletal filaments analogous to that formed by actin in many other amoeboid cells. MSP is a dimeric molecule that polymerizes to form non-polar filaments constructed from two helical subfilaments that wind round one another. Moreover, MSP filaments can interact with one another to form higher-order assemblies without requiring the range of accessory proteins usually employed in actin-based systems. A knowledge of how MSP polymerizes and forms the hierarchical series of helical MSP macromolecular assemblies is fundamental to understanding locomotion in these cells. Here we describe the solution structure of MSP dimers determined by NMR spectroscopy under conditions where MSP does not polymerize to form filaments. The solution structure is indistinguishable from that observed in putative MSP subfilament helices by X-ray crystallography, indicating that MSP polymerization is not accompanied by a major conformational change. We also show that the rate of MSP polymerization associated with movement of vesicles in an in vitro motility assay is enhanced by the presence of magnesium and manganese ions and use NMR to show that the primary residues that bind these ions are 24-25 and 83-86. These residues are distant from the interface formed between MSP dimers in subfilament helices, and so are probably not involved in this level of polymerization. Instead the manganese and magnesium ion binding appears to be associated with the assembly of subfilaments into filaments and their subsequent aggregation into bundles. 相似文献
116.
J Nex?e HE Falk-Petersen S Klit NJ Larsen M Winthereik 《Canadian Metallurgical Quarterly》1998,160(17):2543-2545
The communication of results of HIV tests and chest-X-rays because of persistent coughing are of particular interest because potential life-threatening disease may be disclosed. For HIV tests it is recommended that the result is communicated to the patient in the doctor's office face to face. In this questionnaire study based on two simulated case-stories with a 63 year-old man referred to chest-X-rays because of persistent coughing, and a 27 year-old man, who had been living in Africa for some time, now wanting a HIV test performed, we found that only half (53%) of the general practitioners (GP) did communicate HIV test results in the consultation office. X-ray test results were only communicated in the consultation office by 18% of the GPs. Communication of test results which might have serious implications to the patient should preferably not be done by telephone. Patients should be told of potentially serious results in person by their own physician. 相似文献
117.
J Heller AC Kolbert R Larsen M Ernst T Bekker M Baldwin SB Prusiner A Pines DE Wemmer 《Canadian Metallurgical Quarterly》1996,5(8):1655-1661
Conformational changes in the prion protein (PrP) seem to be responsible for prion diseases. We have used conformation-dependent chemical-shift measurements and rotational-resonance distance measurements to analyze the conformation of solid-state peptides lacking long-range order, corresponding to a region of PrP designated H1. This region is predicted to undergo a transformation of secondary structure in generating the infectious form of the protein. Solid-state NMR spectra of specifically 13C-enriched samples of H1, residues 109-122 (MKHMAGAAAAGAVV) of Syrian hamster PrP, have been acquired under cross-polarization and magic-angle spinning conditions. Samples lyophilized from 50% acetonitrile/50% water show chemical shifts characteristic of a beta-sheet conformation in the region corresponding to residues 112-121, whereas samples lyophilized from hexafluoroisopropanol display shifts indicative of alpha-helical secondary structure in the region corresponding to residues 113-117. Complete conversion to the helical conformation was not observed and conversion from alpha-helix back to beta-sheet, as inferred from the solid-state NMR spectra, occurred when samples were exposed to water. Rotational-resonance experiments were performed on seven doubly 13C-labeled H1 samples dried from water. Measured distances suggest that the peptide is in an extended, possibly beta-strand, conformation. These results are consistent with the experimental observation that PrP can exist in different conformational states and with structural predictions based on biological data and theoretical modeling that suggest that H1 may play a key role in the conformational transition involved in the development of prion diseases. 相似文献
118.
R Hussain HM Dockrell F Shahid S Zafar TJ Chiang 《Canadian Metallurgical Quarterly》1998,114(2):204-209
BACKGROUND: Cough associated with gastroesophageal reflux (GER) may originate in extrathoracic airway receptors made hypersensitive by acid-induced mucosal injury. OBJECTIVE: We investigated the role of laryngeal disease and dysfunction in the pathogenesis of GER-associated cough in nonasthmatic patients. METHODS: Seven patients with GER-associated cough were compared with 7 patients with GER but no cough. The patients underwent fiberoptic endoscopy for assessment of laryngitis and esophagitis (expressed by scores); esophageal manometry; 24-hour pH monitoring; lung function tests; and histamine inhalation challenge with assessment of bronchial threshold (concentration provoking 10% fall in FEV1 [PC10]), extrathoracic airway threshold (concentration provoking 25% fall in the maximal midinspiratory flow [PC25MIF50]), and cough threshold (concentration provoking 5 or more coughs PCcough). The patients were reevaluated after 3 months of medical treatment for GER. RESULTS: Patients with cough, compared with those without cough, had significantly higher laryngitis scores (P = .002), lower esophageal sphincter pressures, longer time with pH below 4 (P = .003), greater number of episodes of reflux longer than 5 minutes (P = .016), longer esophageal clearance time (P = .048), and significantly lower PC25MIF50 (P = .005) and PCcough (P = .008) values. Laryngitis score was significantly inversely related to either PCcough (P < .001) or PC25MIF50 (P <.01) but not to PC10. Laryngitis score, PC25MIF50, and PCcough were all closely related to GER severity. After GER treatment, laryngitis, PC25MIF50, and PCcough were all significantly improved. CONCLUSIONS: These findings suggest that GER-associated cough is strongly associated with laryngeal disease and dysfunction consequent to acid reflux injury in nonasthmatic patients. 相似文献
119.
120.
CO Anjili CK Ngichabe PA Mbati RM Lugalia HM Wamwayi JI Githure 《Canadian Metallurgical Quarterly》1998,74(2-4):315-318
Domestic sheep were intradermally inoculated with culture-derived stationary phase Leishmania donovani promastigotes. Sampling of site of inoculation, liver and spleen for 244 days showed that this parasite can stay alive in the skin for up to 28 days post-inoculation. Apart from pyrexia that was evident in all the animals for 42 days, no other symptoms of kala-azar were seen. No parasites were recovered from the visceral organs throughout the sampling period, suggesting that sheep are not susceptible to infection with L. donovani. It is therefore unlikely that sheep can be synanthropic reservoirs for this parasite. 相似文献