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991.
Sandrine Turcotte Thérèse Laferrière Christine Hamel Alain Breuleux 《Systemic Practice and Action Research》2010,23(4):285-299
Small remote rural schools in Quebec face an ongoing challenge to provide similar quality educational services than bigger
schools. Since 2002, the Remote Network Schools (RNS) initiative afforded schools the opportunity to reinvent their practice
by using online tools to experience collaborative learning activities with other remote schools. Teachers and students experienced
quality learning and demonstrated agency by implementing the RNS in their context. Measures include: diversity of learning
activities, quality of online classroom interactions, changes in teacher beliefs, and shifts in teacher and student roles.
Our results show that it is a viable operating method for such schools and that other schools could contemplate implementing
such innovative practices. 相似文献
992.
Maria C. Shina Annette Müller-Taubenberger Can Ünal Michael Schleicher Michael Steinert Ludwig Eichinger Rolf Müller Rosemarie Blau-Wasser Gernot Glöckner Angelika A. Noegel 《Cellular and molecular life sciences : CMLS》2011,68(2):303-313
Dictyostelium discoideum harbors a short (CRN12) and a long coronin (CRN7) composed of one and two beta-propellers, respectively. They are primarily
present in the cell cortex and cells lacking CRN12 (corA
−) or CRN7 (corB
−) have defects in actin driven processes. We compared the characteristics of a mutant cell line (corA
−
/corB
−) lacking CRN12 and CRN7 with the single mutants focusing on cytokinesis, phagocytosis, chemotaxis and development. Cytokinesis,
uptake of small particles, and developmental defects were not enhanced in the corA
−
/corB
− strain as compared to the single mutants, whereas motility and phagocytosis of yeast particles were more severely impaired.
It appears that although both proteins affect the same processes they do not act in a redundant manner. Rather, they often
act antagonistically, which is in accordance with their proposed roles in the actin cytoskeleton where CRN12 acts in actin
disassembly whereas CRN7 stabilizes actin filaments and protects them from disassembly. 相似文献
993.
Temporal trends of perfluoroalkyl substances (PFASs) have been determined in the blood samples from several countries globally including a female population in Sweden recently, yet little is known about the time trends in the blood levels of these compounds in Swedish male populations over recent years. In this study, the fourteen target PFASs consisted of four perfluorosulfonates (PFSAs) and ten perfluorocarboxylates (PFCAs) in the whole blood samples, collected from 153 Swedish elderly men during the period between 2008 and 2010, were analyzed via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). As the dominant PFASs contaminants in the blood samples, perfluorooctane sulfo- nate (PFOS) showed the highest geometric mean (GM) at 8.5 ng/mL, ranging from 1.7 to 29 ng/mL, while blood perfluorooctanoic acid (PFOA) contained the GM of 1.8 ng/mL, ranging from 0.35 to 6.4 ng/mL. Both the levels of these two compounds were lower than those determined in the blood samples of Swedish elderly pop- ulations derived from the late 1990s. According to the temporal trend analysis, over the three years, the blood levels of PFOS in Swedish male populations declined 16 % per annum, while those of perfluoroundecanoic acid (PFUnDA) increased 6.1% per annum, which were con- sistent with those reported previously for the populations from other countries. 相似文献
994.
In this paper,we propose a new image denoising method that combines total variation(TV) method and wavelet shrinkage. In our method,a noisy image is decomposed into subbands of LL,LH,HL,and HH in wavelet domain. LL subband contains the low frequency coefficients along with less noise,which can be easily eliminated using TV-based method. More edges and other detailed information like textures are contained in the other three subbands,and we propose a shrinkage method based on the local variance to extract th... 相似文献
995.
The security issues of mobile agent system have embarrassed its widespread implementation. The paper analyses communication security threats and countermeasures of mobile agent system and proposes a communication security protocol of mobile agent system. It provides multifactor authentication, encryption transmission, and integrity protection of mobile agent. 相似文献
996.
<正> In this paper,an equivalency condition of nonsingularity in nonlinear semidefinite programming,which can be viewed as a generalization of the equivalency condition of nonsingularity for linearsemidefinite programming,is established under certain conditions of convexity. 相似文献
997.
<正> A family of integral-type goodness-of-fit tests is investigated.This family includes someexisting tests,such as the Cramér-von Mises test and Anderson-Darling test,etc.The asymptoticdistributions of the tests in the family under the null and local alternative hypotheses are established.The almost sure convergence under a fixed underlying distribution is obtained.Furthermore,simulationsare conducted to compare the powers of the tests in the family.Simulation results show that fordifferent alternatives,the more powerful tests are different,and the parameter λ has great influence onthe tests in small sample cases. 相似文献
998.
三维变异函数的稳健统计学计算方法及其应用 总被引:2,自引:0,他引:2
在应用地质统计学进行矿床建模工作中,变异函数的计算和拟合占有非常重要的地位,其结果的好坏将直接影响建模效果.针对传统变异函数计算及拟合方法的缺陷,运用稳健统计学理论,讨论了三维情况下实验变异函数的计算以及拟合方法.矿床建模实践表明,采取上述技术取得了良好的效果. 相似文献
1000.
笔者建议企业树立"人本管理"的思想,探索和寻求适合现代企业发展的用人机制,加强人力资源的开发和利用,为企业留住优秀人才做出贡献. 相似文献