Zfhag的锌指结构和同结构域的基因重组、表达和功能研究

报道了成功地亚克隆Ｚｆｈａｇ的锌指结构和同结构域基因，并将其在细菌体内表达成麦芽糖结合蛋白的融合蛋白的方法和结果，使用这些表达蛋白进行了蛋白－ＤＮＡ相互作用的研究。结果表明：ＭＢＰ－ＺＤ１和ＭＢＰ－ＺＤ２蛋白能与糖蛋白激素的α亚基基因、鼠生长激素（γ－ＧＨ）基因和促甲状腺激素β亚基（ＴＳＨ－β）基因的甲状腺激素反应成分（ＴＲＥ）结合，而不能结合含有天然ＴＲＥ的ＭＨＣ和Ｆ２Ｈ基因，及含有合成ＴＲＥ的ＤＲ４和ＰＡＬ寡核苷酸。     

Uncertainty in traffic forecasts: literature review and new results for The Netherlands

This paper provides a review of transport model applications that not only provide a central traffic forecast (or forecasts for a few scenarios), but also quantify the uncertainty in the traffic forecasts in the form of a confidence interval or related measures. Both uncertainty that results from using uncertain inputs (e.g. on income) and uncertainty in the model itself are treated. The paper goes on to describe the methods used and the results obtained for a case study in quantifying uncertainty in traffic forecasts in The Netherlands.

The importance of time in transit and reliability of transit time for shippers,receivers, and carriers

Reliability of transit time is reputed to be the most important variable influencing freight transport today, according to shipper surveys. Average transit time also plays a major role. A model is developed that shows how a cost-minimizing shipper will adjust its economic order quantity as reliability and/or time in transit changes. Such changes impact on average inventory costs, ordering costs, expected shortage costs and expected excess costs. The model is developed for both discrete and continuous transit time distributions. Reliability is defined as the variance of transit time. A matrix is prepared for some sample data, which shows the minimum cost attainable with each mean/variance of transit time distribution. Comparing across rows and columns of the matrix enables one to show the value (reduction in total cost) obtainable by improving reliability and/or mean transit time. In addition, value can be obtained by improving reliability while increasing average transit time. It is suggested that the model can be used for shippers in negotiating service improvements with carriers and by carriers in negotiating service improvements with shippers. In the former case, the carrier can determine how much they are willing to pay for the improvement, whereas in the latter case, the carriers can determine how much they are able to charge for the improvement.     

Concepts of strategic commercial location: the case of container ports

A World that shrinks with progressive improvements in transportation and communications is a fact of 20th century life. The shrinking process can produce new patterns and perceptions of strategic location. In this paper we are looking specifically at nodes in transportaion system. In the ligth of transportation progress, we re-consider some of the time-worn ideas about centrality, accessibility, gateway locaations, junction, transit points, and the like. Do some of these notions become irrelevant in the modern transport age? Is it a questions f shifting geographical scale? Do we need more sophisticated concepts of strategic location? We suggest the answer 'yes' to all three questions. Our illustrations come from an examination of the world's top-ranked container ports. We give primary emphasis to the external geographical relationships of the ports, that is to situational aspects (not to say, however, that sitefeatures are inconsequetial). We are interested in the seaports users' —i.e., carriers and shippers—perceptions of strategic location. Readily available container throughput data provide and initial platform for empirical research but also give proof that some commercial interests find these ports strategically important to their system.