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21.
Malunions of the hand present a challenging problem to the orthopaedic surgeon. Angular and rotational deformities, and shortening and articular incongruity, can lead to significant functional impairment or dysesthetic appearance. The prevention of malunion should remain a primary goal. When displaced fractures of the metacarpals or phalanges present within the first or second weeks, properly performed closed or open reduction with percutaneous pinning or internal fixation are excellent options with predictable results. Malaligned fractures that present later frequently cannot be readily reduced. Once fully united, treatment options have included corrective osteotomy if function is significantly impaired or if appearance is objectionable; for patients who are not suitable for surgery for medical or other reasons, or for whom appearance is acceptable, intensive occupational therapy to maximize function may yield sufficiently serviceable clinical results. During the past several years, the senior author (BL) has chosen to be more proactive in the prevention of malunions of the hand. In the authors' experience, results of aggressive surgical treatment of subacute, malaligned fractures in selected patients have produced results comparable with or superior to those reported for later reconstructive procedures. With the proliferation of managed care, there has been an increasing frequency of delayed referral patterns for fracture treatment by hand specialists. Definitive treatment of these "impending malunions" is preferable to passive treatment delay and secondary reconstructive procedures, offering both earlier correction of alignment and earlier opportunity for return of function. 相似文献
22.
Rotheram-Borus Mary Jane; Weiss Robert; Alber Susan; Lester Patricia 《Canadian Metallurgical Quarterly》2005,73(2):221
The impact of HIV-related parental death on 414 adolescents was examined over a period of 6 years. The adjustment of bereaved adolescents was compared over 4 time periods relative to parental death and was also compared with the adjustment of nonbereaved adolescents. Bereaved adolescents had significantly more emotional distress, negative life events, and contact with the criminal justice system than nonbereaved youths; these behaviors did not remain significantly higher after parental death. Depressive symptoms and passive problem solving increased soon after parental death, as compared with nonbereaved adolescents. One year subsequent to parental death, depression and passive problem solving were similar to the levels of nonbereaved peers. Only sexual risk behaviors increased following parental death. These results suggest the importance of early family intervention soon after parental HIV diagnosis, prior to parental death, and sustained over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
23.
John T. Y. Wu Sally Dreger Eva Y. W. Chow Evelyn E. Bowlby Lester S. Y. Wong 《Journal of The Association for Laboratory Automation》2003,8(1):46
An enzyme-linked immunosorbent assay (ELISA) for Neospora caninum antibodies was automated with a robotic workstation, the Beckman Coulter Biomek 2000, to screen 200 bovine sera. Comparing these results with manually run ELISA data, a 95.92% agreement (K = 0.9592) between the two assays was obtained. The automated assay was specific and sensitive with excellent positive and negative predictive values. The results were repeatable and reproducible. The automation flexibility was high and the operation complexity was minimal. High-throughput screening (HTS) for bovine antibodies to Neospora caninum was achieved. The assay was developed according to the internationally recognized ISO17025 standard requirements. 相似文献
24.
Modeling Ultrasonic Pulse-Echo Signals from a Flat-Bottom Hole in Immersion Testing Using a Multi-Gaussian Beam 总被引:1,自引:0,他引:1
Hak-Joon Kim Sung-Jin Song Lester W. Schmerr Jr. 《Journal of Nondestructive Evaluation》2004,23(1):11-19
This paper proposes an ultrasonic measurement model that can predict the pulse-echo signals from a flat-bottom hole in an isotropic, homogeneous solid specimen immersed in water in a computationally efficient manner. To develop such a model, a measurement model approach is adopted based on two important assumptions: the paraxial approximation for the transducer beam and the small flaw assumption for the flat-bottom hole. The modular model that results from these two assumptions contains three terms: a diffraction correction term, a far-field scattering amplitude term and a system efficiency factor term. The diffraction correction is defined based on a multi-Gaussian beam model which allows the rapid evaluation of the wave field incident on the hole. The far-field scattering amplitude of the flat-bottom hole is obtained using the Kirchhoff approximation together with the small flaw assumption. The system efficiency factor is determined by deconvolution of an experimental front surface reflection signal by a reference reflector model. Here, the contribution of each of these three terms to the overall measurement model are described in detail and the accuracy of the proposed model is verified by the comparison of the model-based predictions to experiments. 相似文献
25.
Many argue that games can positively impact learning by providing an intrinsically motivating and engaging learning environment for students in ways that traditional school cannot. Recent research demonstrates that games have the potential to impact student learning in STEM content areas and that collaborative gameplay may be of particular importance for learning gains. This study investigated the effects of collaborative and single game player conditions on science content learning and science self-efficacy. Results indicated that there were no differences between the two playing conditions; however, when conditions were collapsed, science content learning and self-efficacy significantly increased. Future research should focus on the composition of collaboration interaction among game players to assess what types of collaborative tasks may yield positive learning gains. 相似文献
26.
Alan Lester 《Landscape Research》2013,38(1):39-49
The ways that British settlers in South Africa, Australia and New Zealand, particularly those engaged in the extension of commercial sheep farming, constructed a certain discourse of colonialism during the first half of the 19th century are discussed. It is argued that this discourse was formulated, at least in part, in opposition to that of humanitarians within each colony and in Britain, who challenged settler capitalist practices on the fringes of Britain's expanding empire. Representations of a civilizing impact on the landscape were one component of the new racialized understandings and identities that settlers at each site constructed in their defence. Through attention to three colonial sites and their relations with each other and with the metropole, it is aimed to highlight the ways in which discourses of colonial landscapes and their inhabitants travelled across an imperial terrain. 相似文献
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29.
Discrete Events in Power Systems 总被引:2,自引:0,他引:2
Lester H. Fink 《Discrete Event Dynamic Systems》1999,9(4):319-330
The relevance of Discrete Event System theory (whether synthetic or analytic) to power system analysis and control is not clear. However, based on several characterizations of the domain of discrete systems set forth in the January 1989 Special Issue of the IEEE Proceedings, on Dynamics of discrete event systems (Ho, 1989), we attempt to delineate several power system control problems that may be amenable to analysis by DEDS methodologies. While the author is not qualified to judge whether the latter can speak to any of the examples, it may be relevant that in all cases the problems are non-trivial and in need of further contributions toward improved solutions, especially in view of the ongoing radical restructuring of the industry. The continuous process that is instantiated in the functioning of a power system is observed via three more or less diverse variables. Two of these, the scaler system frequency and the vector system voltage profile, are in principle mensurable physical phenomena; the third, system security, is a quality represented by a set membership conditioned on an inferred relationship between the two physical system variables and future realizations of one or more classes of autonomous stochastic phenomena. (These latter may be internal or external to the physical system, such as, e.g., respectively, equipment failure mechanisms and weather events.) 相似文献
30.
FT Bosman 《Canadian Metallurgical Quarterly》1998,118(9):807-812