创建优质园林工程 标准规范应先行

从创建优质园林工程的角度,分析了园林工程诸环节存在的问题及其对工程质量的影响,探讨了各环节工作的规范化对工程质量的重要性。建议要提高园林工程质量,当务之急是要有严格的资质管理制度并制订一套与工程质量相关的切实可行的标准规范。     

Parasitology. Close encounters: good, bad, and ugly

Microbiologists often focus on one organism and its relationship to its host at one point in time. But viewed in light of evolution, host-parasite relationships range from deadly to helpful, depending on the communication between them. At a meeting here last month of virologists, bacteriologists, parasitologists, and molecular biologists--each dealing with different microorganisms in distinct ways--researchers lamented that evolution is often considered outside the bailiwick of microbiologists, particularly those studying infectious diseases.     

Prime tests and keeping proofs secret

Stanford, California. On 29 July through 2 August, a group of computer scientists, mathematical physicists, and mathematicians met at Stanford University for a conference on Mathematics and Computers. It was a varied meeting-the talks ranged from the mathematics of chaos to a talk by the peripatetic Hungarian mathematician Paul Erdos on number theory problems that might be interesting to work on. In addition, software vendors set up shop, inviting investigators to bring their problems and try them on different systems. On the last day of the conference, when the talks were in the field of computational complexity-the difficulty of doing certain computer calculations-two new computer science tricks were presented and are recounted here.