Acquiring unpublished population documents in Africa: a personal experience

Acquiring both published and unpublished documents produced in Africa is, generally, a difficult task due to the existing poor state of bibliographic control and the publishing industry. It is even more difficult to obtain unpublished documents in a specialized area of study such as demography--a diffuse area which cuts across several disciplines. This paper discusses the problems encountered on acquisition trips to some African countries to acquire unpublished population material. To help solve the problems, the Population Association of Africa must persuade its members to send copies of their publications to population libraries and documentation centers in their individual countries for dissemination to the other users in Africa. The various organizations and institutions in Africa engaged in the teaching and research of population studies should have an agreement to exchange copies of their theses. The Economic Commission for Africa (ECA) and the Organization of African Unity (OAU) should make representations to the various African member countries on the need to disseminate the results of vital censuses and surveys conducted. Finally, the Population Information Network for Africa (POPIN-AFRICA) with its coordinating unit at the population division of ECA should ensure that all the nodes of the network have the financial and other resources to be able to acquire the relevant documents needed for their operations.     

低温超导"热"起来

设想你在家里后院走着走着，突然在一个你自以为洞悉一切的角落里发现了金矿脉；再设想一下电影《豪门新人类》(Beverly Hillbillies)里，Jed Clampett发现石油从地下滚滚而出时的惊喜。2001年初的几个星期，当有研究人员称二硼化镁在温度接近40K时电阻为零，即具备超导性，固体物理学界就沉浸在这种惊喜之中。     

Parental training and involvement in sexuality education for students who are deaf

The study examined whether schools for the deaf were providing services to assist parents in communicating with their children about sexuality (including sexual signs) and whether parents were involved in the sexuality education curriculum within their child's school. The Sexuality Curriculum Questionnaire for Educators of Students Who Are Deaf (Getch & Gabriel, 1998) was completed by 71 educators teaching sexuality curricula in schools for the deaf across the United States. Results indicated that parents were more likely to be involved in approval and development of their children's sexuality education than to receive assistance with sexuality education from the schools. Although the level of parental participation in curriculum development and approval is encouraging, the number of parents actually participating in curriculum development and approval remains low.     

帮助生产队抗旱……

一九六三年,余干县金埠小学积极支援了农业生产,在不影响教学的原则下,主要做了以下三项工作:①抬水抗旱。去年春季久旱不雨,给春耕生产带来了严重的困难。在这种情况下,金埠小学的领导积极组织了全校师生各赴原来的挂钩生产队,用水桶等盛水工具抬水抗旱,灌田十几亩。②耘禾。达里的社员们都有精耕细作的传统,每季稻一股都要耘禾三遍。每逢耘禾季节,生产队里的劳动是比较紧张的。为了支援农业生产,帮助社员及时做好中耕除草工作,学校组织全校师生帮助生产队耘禾一百多亩。③送肥。学校里的人粪尿每年都是无代价的定期送给生产队。通过上述劳动,既支援了农业生产,又使全体师生受到了劳动锻炼,进一步培养了他们热爱劳动和劳动人民的思想感情。     

Rapid and cost-effective fabrication of selectively permeable calcium-alginate microfluidic device using "modified" embedded template method

In this paper, we have presented a non-lithographic embedded template method for rapid and cost-effective fabrication of a selectively permeable calcium-alginate (Ca-alginate) based microfluidic device with long serpentine delay channel. To demonstrate the versatility of the presented method, we have demonstrated two different strategies to fabricate serpentine long delay channels without using any sophisticated microfabrication techniques, in formal lab atmosphere. The procedure presented here, also, enables the preparation of a multilayered microfluidic device with channels of varying dimensions, in a single device without using any sophisticated micromachining instrumentation. In addition, we have also qualitatively studied the diffusion of small and large molecules from a Ca-alginate based microfluidic device and proposed a method to effectively control the out-flow of macro biomolecules from the crosslinked Ca-alginate matrix to create a selectively permeable matrix required for various biological and biomimetic applications, as mentioned in the Introduction section of this work.