Algae on the internet

Increasingly electronic communication and a variety of electronic resources are accessible to a larger group of people within the scientific community. This paper outlines the range of resources that are available, and comments on their current and future value to the phycological community. Resources discussed include mailing lists and newsgroups. These are useful tools for rapid, informal, targeted communication, although the technology employed places limitations on the type and format of information which may be distributed. The World Wide Web (WWW) has the potential to overcome these limitations, the quality, complexity and value to the phycological community of the sites on the WWW are extremely variable, with some material being of dubious quality. However, it is possible to access high quality resources including culture collection catalogues, high quality images and microbial and molecular databases. As well as some of the current resources, this paper discusses some possible directions for the future of phycology on the internet.http://wiua.nwi.ac.uk/     

Using computer-based tutorials to encourage reflection

There is some evidence to suggest that undergraduate biology students need to be given more opportunities for reflection in their education. Some argue that computer-based learning packages may be able to offer such opportunities. This paper presents four different approaches to defining what reflection is and how it can be promoted. These approaches are then used to discuss and review the different ways in which computer-based tutorials can be used to promote lateral thinking. An example of a web-based biology tutorial called ‘How Now Mad Cow’ is described and preliminary evaluation results are presented, in order to illustrate how students may be encouraged to reflect and what factors may influence that. Finally, the role of the tutor in enspiring students to reflect while using computer-based tutorials is discussed. This distinguishes between the role of the tutor in designing a computer-based tutorial, and the role of the tutor in determining and facilitating how a student uses a tutorial once it has been designed.     

Analysis of topological and nontopological structural similarities in the PDB: New examples with old structures

We have developed a new method and program, SARF2, for fast comparison of protein structures, which can detect topological as well as nontopological similarities. The method searches for large ensembles of secondary structure elements, which are mutually compatible in two proteins. These ensembles consist of small fragments of C^α-trace, similarly arranged in three-dimensional space in two proteins, but not necessarily equally-ordered along the polypeptide chains. The program SARF2 is available for everyone through the World-Wide Web (WWW). We have performed an exhaustive pairwise comparison of all the entries from a recent issue of the Protein Data Bank (PDB) and report here on the results of an automated hierarchical cluster analysis. In addition, we report on several new cases of significant structural resemblance between proteins. To this end, a new definition of the significance of structural similarity is introduced, which effectively distinguishes the biologically meaningful equivalences from those occurring by chance. Analyzing the distribution of sequence similarity in significant structural matches, we show that sequence similarity as low as 20% in structurally-prealigned proteins can be a strong indication for the biological relevance of structural similarity. © 1996 Wiley-Liss, Inc.     

Video on the Internet: An introduction to the digital encoding, compression, and transmission of moving image data

In this paper, we seek to provide an introduction to the fast-moving field of digital video on the Internet, from the viewpoint of the biological microscopist who might wish to store or access videos, for instance in image databases such as the BioImage Database (http://www.bioimage.org). We describe and evaluate the principal methods used for encoding and compressing moving image data for digital storage and transmission over the Internet, which involve compromises between compression efficiency and retention of image fidelity, and describe the existing alternate software technologies for downloading or streaming compressed digitized videos using a Web browser. We report the results of experiments on video microscopy recordings and three-dimensional confocal animations of biological specimens to evaluate the compression efficiencies of the principal video compression-decompression algorithms (codecs) and to document the artefacts associated with each of them. Because MPEG-1 gives very high compression while yet retaining reasonable image quality, these studies lead us to recommend that video databases should store both a high-resolution original version of each video, ideally either uncompressed or losslessly compressed, and a separate edited and highly compressed MPEG-1 preview version that can be rapidly downloaded for interactive viewing by the database user.     

利用WWW检索蓖麻资源信息的方法与技术

阐述了在Ｉｎｔｅｒｎｅｔ网上利用ＷＷＷ系统和它的主要检索工具进行蓖麻资源的科技文献、市场经济信息与新产品开发情报的检索方法与检索技术     

A serious problem with computer processing of stereochemistry in chemical structure files: The need for standardisation

Many computer programmes exist for drawing and modelling small and large molecules. Small molecules related to the antitubercular drug ethambutol are discussed. Some specific software problems, with stereochemical representations, are illustrated. Incompatibility of molecular structure files produced by different programmes and different hardware are shown. The need for a standardised file format is stressed. © 1995 Wiley-Liss, Inc.