欧洲电信管制难脱旧日窠臼

欧盟的电信管制陷入了与国家政体冲突的泥潭中,尽管高层有一些关于改革的勇敢论调,但事实胜于雄辩。欧盟所规定的电信规则设想在这个有25个国家、超过4．5亿人口的市场,以远远超出这个范围的影响创造一个公平的竞争环境,它能奏效吗?于布鲁塞尔制定的电信政策在许多方面呈现多极化趋向,这反映了对泛欧“超级国家”实体更大的争议。根据每天问题的不同,随着观点的转移,欧洲电信规则被同等程度地喜爱和痛恨着。对一方来说很协调的东西,对另一方则成了毫无根据     

Cardiac tamponade as a presentation of primary hypothyroidism in a young woman

Pericardial effusion (PE) as a hypothyroidism associated sign, is something that can be found with relative frequency; nevertheless, cardiac tamponade (CT) as the first sign of this disease may be considered exceptional especially in young patients. We report a 31 years old woman with clinical symptoms and signs of CT that in the forward workshop was diagnosed of primary hypothyroidism as cause of the CT. We shortly describe the case and review the literature, emphasizing the importance of the knowledge of CT trigger factors in myxedematous PE, as well as its usual benign evolution with hormonal treatment, without recurrences of the CT after pericardiocentesis is performed. This justify a conservative approach, in spite of the slow resolution of the PE what can take as long as 1.5 years.     

Revising deductive knowledge and stereotypical knowledge in a student model

A user/student model must be revised when new information about the user/student is obtained. But a sophisticated user/student model is a complex structure that contains different types of knowledge. Different techniques may be needed for revising different types of knowledge. This paper presents a student model maintenance system (SMMS) which deals with revision of two important types of knowledge in student models: deductive knowledge and stereotypical knowledge. In the SMMS, deductive knowledge is represented by justified beliefs. Its revision is accomplished by a combination of techniques involving reason maintenance and formal diagnosis. Stereotypical knowledge is represented in the Default Package Network (DPN). The DPN is a knowledge partitioning hierarchy in which each node contains concepts in a sub-domain. Revision of stereotypical knowledge is realized by propagating new information through the DPN to change default packages (stereotypes) of the nodes in the DPN. A revision of deductive knowledge may trigger a revision of stereotypical knowledge, which results in a desirable student model in which the two types of knowledge exist harmoniously.