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101.
三网融合技术发展研究   总被引:1,自引:0,他引:1  
闵曙辉  李普玉  曹向 《科技广场》2009,(11):216-218
三网融合意味着视频、信息、通信业务的融合.我国早巳形成了电信网,计算机网,有线电视网这三大网络共存的局面.随之兴起的三网融合的发展热潮,对有线电视网来说,三网融合的发展大大促进了广播电视的数字化.本文详细讲述三网融合及其在国内外发展的状况,还介绍了作为三网融合开端的IPTv技术发展状况,以及将来我国三网融合的一些问题和发展前景.  相似文献   
102.
Existing literature has generally focused on organizational memory (OM) and workforce agility. Yet, less concentration has been devoted to the impact of workforce agility on OM. This research proposed a model that studies the impact of workforce agility on declarative OM and procedural OM. The model focused on aspects related to proactivity, adaptability, and resiliency. The study targeted the cell phone industry in Jordan. The study sample included 430 individuals involved in managerial and professional knowledge positions in mobile communications companies in Jordan. The article concluded that a proactive workforce has a significant impact on declarative OM and proactivity also improves procedural OM. Consequently, practical implications for managers, and suggested future research are presented.  相似文献   
103.
Experimental model of chronic renal failure in rats have been described by many authors and has also been widely used in various studies. Many of these methods used highly sophisticated instruments which was difficult in our settings. The resection model was ideal in our experimental set-up, but this model had the risk of excessive bleeding and hypovolemia. In our study we used a combination of partial resection and ligation of the renal artery to create two models of stable uremia A and Moderate uremia B. Severe uremia. Both these models were compared with a sham operated group which served as controls. Following surgical procedure, the development of uremia was monitored by serial estimation of blood urea and serum creatinine levels that were measured at regular intervals (bi-weekly). From two weeks onwards the animals in the experimental group showed a significant elevation in the serum urea levels and a consistent elevation in the serum creatinine levels upto eight weeks when compared to the animals in the sham operated group. We established a modified method of producing renal failure which can be maintained for a period of six weeks. This model is simple, reproducible and less complicated that can be used for several studies relating to renal failure in the field of research.  相似文献   
104.
    
This paper aims to provide new insights to debates on group privacy, which can be seen as part of a social turn in privacy scholarship. Research is increasingly showing that the classic individualistic understanding of privacy is insufficient to capture new problems in algorithmic and online contexts. An understanding of privacy as an “interpersonal boundary-control process” (Altman, The environment and social behavior, Brooks and Cole, Monterey, 1975) framing privacy as a social practice necessary to sustain intimate relationships is gaining ground. In this debate, my research is focused on what I refer to as “self-determined groups” which can be defined as groups whose members consciously and willingly perceive themselves as being part of a communicative network. While much attention is given to new forms of algorithmically generated groups, current research on group privacy fails to account for the ways in which self-determined groups are affected by changes brought about by new information technologies. In an explorative case study on self-organized therapy groups, I show how these groups have developed their own approach to privacy protection, functioning on the basis of social practices followed by all participants. This informal approach was effective in pre-digital times, but online, privacy threats have reached a new level extending beyond the scope of a group’s influence. I therefore argue that self-determined sensitive topic groups are left facing what I present as a dilemma: a tension between the seemingly irreconcilable need for connectivity and a low threshold, on the one hand, and the need for privacy and trust, on the other. In light of this dilemma, I argue that we need new sorts of political solutions.  相似文献   
105.
Curcumin is a natural anti-inflammatory and antioxidant with several potential health benefits. Although it has been examined in several metals toxicity studies, but its role in the protection against copper toxicity has not been investigated. In this study; the detoxification and antioxidant effect of curcumin were examined to determine its prophylactic/therapeutic role experimentally in rats. Forty albino rats were divided into five groups; control, CuSO4 (4 mg/kg body weight), curcumin (80 mg/kg body weight), curcumin post-treatment (CuSO4 for 15 days followed by curcumin for the next 15 days) and curcumin co-treatment (CuSO4 plus curcumin for 30 days). All rats were treated orally by stomach tube for 30 days/once a day. Changes were observed in hepatic marker enzymes such as: aspartate aminotransferase (AST), alanine transaminase-(ALT), alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT), besides the serum total protein, urea and creatinine. Concentration of liver and kidney antioxidants such as: catalase (CAT), superoxide dismutase (SOD), reduced glutathione-(GSH) and malondialdehyde (MDA) were measured. An increased in the activities of liver marker enzymes, urea, creatinine and the MDA contents were detected after exposure to CuSO4. Meanwhile, the activities of serum total protein, hepatic and renal antioxidants were decreased. Changes in all biochemical parameters were alleviated by the post-treatment and co-treatment of curcumin. Our finding suggests that the curcumin showed protective effects on CuSO4-induced hepatotoxicity and nephrotoxicity.  相似文献   
106.
107.
    
In four experiments with rats, we examined the persistence of behavior when reinforcement was switched from immediate to delayed. In Experiment 1, lever pressing elicited by instrumental training with immediate reinforcement continued when a 20-sec delay of reinforcement was introduced (easy-to-hard condition), whereas when the delay condition was introduced from the start (hard-to-hard condition), responding remained low throughout. A similar result was obtained in Experiment 2, in which lever pressing was elicited by a classical conditioning (autoshaping) procedure. In Experiment 3, rats initially trained with delayed reinforcement continued to respond at a low rate when switched to immediate reinforcement (hard-to-easy condition). By measuring magazine entry (goal tracking) as well as lever pressing (sign tracking) in Experiment 4, we confirmed that such transfer effects at least partly involve the persistence of whatever type of behavior was initially dominant.  相似文献   
108.
This study was conducted to examine the factors that influence informational text comprehension and to determine how these vary for students with higher and lower component skills. The sample included 177 students in grades 3–5. Regression analyses were used to predict informational text comprehension with decoding efficiency, vocabulary knowledge, prior knowledge, and intrinsic motivation. This model, that also included age and grade as control variables, explained 62.5 % of the variance in informational text comprehension. Each component skill explained unique variance, and vocabulary knowledge accounted for the largest portion. Next, we examined whether the factors contributed differently to informational text comprehension for students with higher and lower component skills. Overall, the regressions were better predictors for students with higher than those with lower component skills. For students with lower component skills, motivation and vocabulary were consistent predictors, whereas vocabulary and decoding efficiency were consistent predictors for students with higher component skills. The findings indicate multiple factors are important for informational text comprehension, particularly vocabulary, and research should examine this topic for different types of readers.  相似文献   
109.
This article argues that the stance toward global regulatory initiatives is influenced by the extent to which these regulatory initiatives threaten the comparative institutional advantages of the national economy. The cases through which this proposition is examined are the showpieces of Germany and Ontario: their system of vocational education and training. The article draws on the Varieties of Capitalism literature to explore the factors that implicated the most into the educational reforms introduced in Germany in the context of the Bologna Process. In the case of Ontario, the paper used educational reforms in the context of two OECD reports, Learning for Job and A Skills beyond School. The paper concludes that comparative institutional advantage and the institutional complementarity sustaining it explain the different trajectories countries take in their response to global pressures.  相似文献   
110.
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