Animal chamber for in vivo testing of toxic gases

A closed-circuit chamber system for exposing animals to toxic concentrations of oxygen or nitrogen was designed and built. The facility was equipped with systems for the removal of carbon dioxide, ammonia, methane, water vapor, and particulates from the gas stream. Integral systems were built to monitor and control temperature (+/- 1 degree C), relative humidity (+/- 2%), oxygen concentration (10 to 100% +/- 0.5%), and methane concentration (below 2%). Operation was set at standard pressure (1.0 X 10(5) Newtons/m2). Hyperoxic studies have been performed on six species of rodents, as well as sheep, and have lasted from 1 to 28 days.     

Synthesis of diphtheria toxin in E. coli cell-free lysate

An $\text{E. coli}$ cell-free lysate was used to translate $\text{C. diphtheriae}$ RNA from nontoxinogenic C₇(?), C₇ infected with β tox⁺ corynebacteriophage, and $\text{C. diphtheriae}$ strain PW8. De novo synthesis of toxin was detected by immune precipitation with antitoxin, ADP-ribosylation of mammalian elongation factor 2 and rabbit skin test. The results indicated that toxin is produced in the $\text{E. coli}$ protein synthesizing system primed with RNA from cells infected with tox⁺ bacteriophage and is absent in systems primed with RNA from C₇(?) cells.     

尊重斯德哥尔摩的历史中心—骑士岛的激活改造

瑞典国家财产委员会拥有骑士岛的所有权与管理权，并计划对该岛上所有的公共空间进行更新和开发，以提高其可达性与吸引力。该项目的核心是找到一种更新和修复岛屿的方法，从而在尊重历史价值的同时满足现代功能需求。对骑士岛南部的改造是岛上公共空间更新的第一部分。设计的关键条件是沿滨水区域创造可以供人步行与停坐的大面积空间，并在保持开放海港氛围的同时，对旧的道路铺装进行管理。设计者设计了一套灵活使用公共空间的综合解决方案，将开放空间与之前的码头一样，沿着水滨的形态进行布局。     

Duplicate split samples for internal quality control in routine water microbiology

In the microbiological examination of water, indicator organisms are sought by membrane filtration of 100-ml sub-samples of water. The same sample cannot be examined twice but the use of split samples, where two 100-ml sub-samples from the same batch are processed, has been explored. Binomial theory was used to determine the 95% confidence intervals for the results obtained. Two sets of 50 results were assessed by the method and the resulting control charts are illustrated.     

Detection of a homologue to an E. coli glutamate synthase gene in a cyanobacterium

The gltBY locus of E. coli, which codes for the two subunits of pyridine nucleotide dependent glutamate synthase, was used as a probe to detect homologues in genomic DNA of Synechococcus PCC6301, a unicellular cyanobacterium. Non-overlapping probes from gltB detected a single homologue with extensive homology, however gltY probes do not detect a strong homologue. The possibility that the gltB homologue encodes a ferredoxin-dependent glutamate synthase of the type found in cyanobacteria, algae and plants is discussed.