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Transgenic alfalfa plants harboring a gene fusion between the soybean leghemoglobin (lbc3) promoter region and the chloramphenicol acetyl transferase (cat) gene were used to determine the influence of rhizobial mutants on lb gene expression in nodules. The promoter region of the Sesbania rostrata glb3 (Srglb3) leghemoglobin gene was examined for the presence of conserved motifs homologous to binding site 1 and 2 of the soybean lbc3 promoter region, found to interact with a trans-acting factor present in soybean nodule nuclear extracts (Jensen EO, Marcker KA, Schell J, de Bruijn FJ, EMBO J 7:1265-1271, 1988). Subfragments of the S. rostrata glb3 (Srglb3) promoter region were examined for binding to trans-acting factors from nodule nuclear extracts. In addition to the binding sites previously identified (Metz BA, Welters P, Hoffmann HJ, Jensen EO, Schell J, de Bruijn FJ, Mol Gen Genet 214: 181-191), several other sites were found to interact with trans-acting factors. In most cases the same trans-acting factor(s) were shown to be involved. One fragment (202) was found to bind specifically to a different factor (protein) which was extremely heat-resistant (100 degrees C). The appearance of this factor was shown to be developmentally regulated since the expected protein-DNA complexes were first observed around 12 days after infection, concomitant with the production of leghemoglobin proteins. Fragments of the Srglb3 5' upstream region were fused to the beta-glucuronidase reporter gene with its own CAAT and TATA box region or those of the cauliflower mosaic virus 35S and nopaline synthase (nos) promoters.(ABSTRACT TRUNCATED AT 250 WORDS)

A methodology for a statistical trend analysis (STA) in failure rates is presented. It applies primarily to relatively rare events in changing technologies or components. The formulation is more general and the assumptions are less restrictive than in a previously published version. Relations of the statistical analysis and probabilistic assessment (PRA) are discussed in terms of categorization of decisions for action following particular failure events. The significance of tentatively identified trends is explored. In addition to statistical tests for trend significance, a combination of STA and PRA results quantifying the trend complement is proposed. The STA approach is compared with other concepts for trend characterization.

The historical development of steam boiler technology aboard steam- and later motor-ships is reviewed, setting the stage for statistical investigations of langer term trends in the frequency of boiler explosions. Two different measures of the safety performance have to beaddressed in such an analysis: The explosion rate per ship- or boiler-year in an entire fleet, and the failure ratio, i.e. the probability that a boiler of a certain vintage suffers an explosion during his useful life. The major obstacle for both analyses, the distortions due tostatistical fluctuations, have been dealt with by applying a special smoothing procedure. The failure ratio analysis requires further an estimation of failures to be statistically expected in the future; this is accomplished by means of a previously developed methodology. This paper is primarily concerned with the statistical analysis of boiler exolosion data. The methodology is published elsewhere.

Previous R&D work for the introduction of methanol as an alternative fuel for passenger cars, trucks, industrial burners and hause heating systems was based on the assumption of ever decreasing resources of fossil fuels. As a result of this work cars were developed with engines adapted to the different properties of methanol. Worldwide fleet test programs, and especially the Brazilian Alcohol Program, have clearly shown that alcohols are the best alternative to replace common fuels. Since that time, with the increasing demand for environmental protection and decreased energy supply difficulties, a second generation of methanol technologies has appeared. There are new prototype alcohol cars which are even superior to gasoline cars with modern catalytic converters. The use of a clean fuel further helps to avoid costly and complicated administrative controls. A similarly favourable situation exists for the introduction of methanol as a clean-burning fuel in heating and firingsystems. Methanol with its low carbon/hydrogen ratio represents a big step towards hydrogen technology with which lowest level pollution finally seems to be achievable.

Evaluating the safety of large dams by means of an average value of failures taken over a lang time-span of dam history leads to inadequate results, since it eliminates most of the declining trend. It appears that an analysis that evaluates the trend as such is required to obtain a proper assessment of the safety performance as a basis for failure prognosis and thereby for decision making an investments. Trends appear in dependencies an three different variables: yearof failure, year of construction,and age. Two different methods are presented to analyze these trends: one method for the trend analysis of the fatlure occurrence in time for a dam population, and a secend method for the combined analysis of trends in the construction year and age dependencies. The first method is applied to large dams in the U.S.A. and in Western Europe built after 1850, combined as well as for individual dam types, whereas the secend method is only applied to U.S. embankment dams because of its more extensive data requirements.

Objektorientiertes Programmieren unter Verwenden von Smalltalk wird am Beispiel eines Notizkalenders erläutert. Der Aufsatz ist weder ein Lehrbuch über Smalltalk als Programmiersprache noch eine musterhafte Vorstellung des Smalltalk Programmiersystems. Der Aufsatz soll Interesse wecken und zum intensiveren Beschäftigen mit objektorientiertem Programmieren und mit Smalltalk anregen, auch zeigen, wie man mit solchen Systemen umgeht. Er enthält eine kommentierte Bibliographie.

The primary structure of a leghemoglobin (lb) gene from the stem-nodulated, tropical legume Sesbania rostrata and two lb gene promoter regions was analysed. The S. rostrata lb gene structure and Lb amino acid composition were found to be highly conserved with previously described lb genes and Lb proteins. Distinct DNA elements were identified in the S. rostrata lb promoter regions, which share a high degree of homology with cis-active regulatory elements found in the soybean (Glycine max) lbc3 promoter. One conserved DNA element was found to interact specifically with an apparently universal, trans-acting factor present in nuclear extracts of nodules. These results suggest a conserved mechanism for nodule specific induction of lb genes in leguminous plants. Udgivelsesdato: 1988-Oct

A methodology for statistically analysing rare failure events is proposed that may allow an improved evaluation of the longer term progress of the safety performance during the continuing evolution of a technology. The actuarial data base consists of the record of major failures, especially, construction year and age for the failed units, as well as construction rate and size of population. The state-of-the-art of safety is quantified by the failures up to the same age, that requires an augmentation of the actuarial information. A refined (average) age variation of the failure occurrence that is formally derived from the data is employed for the augmentation of the actual failure information. The application of this method is illustrated for the evaluation of the progress of the safety of large embankment dams in the U.S. for the period 1850 through 1980.