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Vulnerability analysis provides an assessment of the likelihood of system failure in a man‐made hostile environment, involving sabotage, security compromise and combat damage. The fault‐tree approach proved most useful as many obscure but significant failure modes surfaced as a result of the step‐by‐step logic involved. Analysis tools were applied to the problems of nuclear reactor sabotage, space shuttle and combat system vulnerability. An increased qualitative understanding of system vulnerabilities, the effectiveness of counter‐measures and the ranking of scenarios by their attractiveness to saboteurs or other adversaries were the chief results of the work.

The results of a study of the reliability of the Los Alamos National Laboratory electrical system are discussed and an assessment of the risk arising from power interruptions is made. The study was intended to provide a current status of the system and to rank modifications to improve the system. Fault‐tree analysis, cause‐consequence analysis, and directed graphs were used. The study resulted in a ranking of the relative importance of the consequences of power loss to various Los Alamos technical sites and facilities, sets of equipment whose failure will lead to loss of power to the sites, and statistical estimates of the frequency of power loss to sites and facilities.

This article describes a programme planning tool for complex research and development projects called the Process Tree Management Tool (PTMT). The PTMT was developed for use in programme management for a particular large, diverse, advanced weapon system. The PTMT includes a set of logic diagrams and specially developed software for manipulating the information represented by the logic diagrams. Two logic diagrams are included in the PTMT in its current form. One diagram, called a process tree, graphically represents the physical processes that occur when an engineered system functions successfully. Another, called a programme tree, includes gates representing elements of a successful research, development, and fabrication programme. These trees are used in conjunction to store programmatic and scientific information useful for a manager of a large, technical research and development programme. The objective of this article is to explain the methodology involved in development of the process tree and its associated programme tree and to describe a computer software tool based on the HYPERTALK language that make the logic diagrams vastly more useful to the manager. The methodology is illustrated by a relatively simple and understandable example.

A highly significant action taken by the Minister of Agriculture, Fisheries and Food, reported elsewhere in this issue, could well result in important advances in surveillance and probably legislative control over enforcement of certain aspects of EEC legislation in the Member‐states. The Minister has sent an urgent request to the Commission in Brussels to dispatch inspectors to each country, including the United Kingdom, to examine and report on the standards of inspection and hygiene with detailed information on how the EEC Directive on Poultry Meat is being implemented. Information of the method of financing the cost of poultrymeat inspection in each country has ben requested. The comprehensive survey is seen as a common approach in this one field. The Minister requested that the results of the inspectors' reports should be available to him and other Member‐states.

The findings of the Steering Group on Food Freshness in relation to the compulsory date marking of food contained in their Report, reviewed elsewhere in this issue, has brought within measurable distance the Regulations which were, in any case, promised for1975. The Group consider that the extension of voluntary open date marking systems will not be sufficiently rapid (or sufficiently comprehensive) to avoid the need or justify the delay in introducing legislation.

From earliest times the land and all it produced to feed and sustain those who dwelt on it was mankind's greatest asset. From the Biblical “land of milk and honey”, down through history to the “country of farmers” visualised by the American colonists when they severed the links with the mother country, those who had all their needs met by the land were blessed — they still are! The inevitable change brought about by the fast‐growing populations caused them to turn to industry; Britain introduced the “machine age” to the world; the USA the concept of mass production — and the troubles and problems of man increased to the present chaos of to‐day. There remained areas which depended on an agri‐economy — the granary countries, as the vast open spaces of pre‐War Russia; now the great plains of North America, to supply grain for the bread of the peoples of the dense industrial conurbations, which no longer produced anything like enough to feed themselves.

The purpose of this article is to understand when and why employees engage in contextual performance directed toward one's organization and immediate supervisor.

A survey was conducted to measure study variables. Data collected from 158 professional employees were subjected to confirmatory factor analysis and moderated hierarchical analysis was used to test hitherto untested hypotheses.

Results indicate strong support for the hypothesized moderating effects, such that high levels of support compensated for low levels of conscientiousness in influencing contextual performance.

Although contextual performance is unlikely to influence one's level of conscientiousness, the cross‐sectional design of the study does not permit firm conclusions regarding causality for the influence of support on contextual performance.

Results indicate that, by providing organizational and supervisory support, organizations will be able to elicit contextual performance from those individuals who lack the personality predisposition to engage in contextual performance. Given the importance of contextual performance, the practical implications of study results are of immense value.

This study makes several contributions. For instance, it extends Motowidlo et al.'s theory to include subjective measures of situational conditions as factors that interact with personality to influence contextual performance. The study responds to LePine et al.'s call for theory‐based attempts to identify variables that have differential relationships across dimensions of contextual performance. Drawing on individual difference and social exchange perspectives, this study theorized and found that perceived organizational support moderates the relationship between conscientiousness and organization‐directed contextual performance, and that the quality of the leader‐member exchange experience moderates the relationship between conscientiousness and supervisor‐directed contextual performance.

The long controversy that has waxed furiously around the implementation of the EEC Directives on the inspection of poultry meat and hygiene standards to be observed in poultry slaughterhouses, cutting‐up premises, &c, appears to be resolved at last. (The Prayer lodged against the Regulations when they were formally laid before Parliament just before the summer recess, which meant they would have to be debated when the House reassembled, could have resulted in some delay to the early operative dates, but little chance of the main proposals being changed.) The controversy began as soon as the EEC draft directive was published and has continued from the Directive of 1971 with 1975 amendments. There has been long and painstaking study of problems by the Ministry with all interested parties; enforcement was not the least of these. The expansion and growth of the poultry meat industry in the past decade has been tremendous and the constitution of what is virtually a new service, within the framework of general food inspection, was inevitable. None will question the need for efficient inspection or improved and higher standards of hygiene, but the extent of the

Presents the development and implementation of a four‐dimensional variational (4D‐var) data assimilation technique for a comprehensive Eulerian chemistry‐transport model. The method aims at analysing the chemical state of the atmosphere on the basis of trace gas observations with arbitrary distribution in time and space, a chemistry‐transport model, and a priori knowledge as available from climatological records or preceding model runs. The model under consideration is the University of Cologne EURAD‐CTM2 with the full RADM2 gas phase mechanism. Describes the storage and recalculation strategy of a parallel implementation of the 4D‐var method and first experiences of its performance, when model generated data are provided as artificial observations. The problem of pre‐scaling the minimization problem is discussed in some detail. It is found that the algorithm is well suited to adapt the model trajectory to the observation data.

Reports of a number of countries imposing a limited ban on the use of D.D.T. have appeared from time to time in the B.F.J., but in the last few months, what was a trickle seems to have become an avalanche. In Canada, for example, relatively extensive restrictions apply from January 1st, permitting D.D.T. for insect control in only 12 agricultural crops, compared with 62 previously; there is a reduction of maximum levels for most fruits to 1 ppm. Its cumulative properties in fat are recognized and the present levels of 7 ppm in fat of cattle, sheep and pigs are to remain, but no trace is permitted in milk, butter, cheese, eggs, ice cream, other dairy products, nor potatoes. A U.S. Commission has advised that D.D.T. should be gradually phased out and completely banned in two years' time, followed by the Report of the Advisory Committee on Pesticides and Other Toxic Chemicals recommending withdrawal in Britain of some of the present uses of D.D.T. (also aldrin and dieldrin) on farm crops when an alternative becomes available. Further recommendations include an end to D.D.T. in paints, lacquers, oil‐based sprays and in dry cleaning; and the banning of small retail packs of D.D.T. and dieldrin for home use in connection with moth‐proofing or other insect control. The Report states that “domestic users are often unaware that using such packs involve the risk of contaminating prepared food immediately before it is eaten”.