Identifying component modules

A computer-based system for modelling component dependencies and identifying component modules is presented. A variation of the Dependency Structure Matrix (DSM) representation was used to model component dependencies. The system utilises a two-stage approach towards facilitating the identification of a hierarchical modular structure. The first stage calculates a value for a clustering criterion that may be used to group component dependencies together. A Genetic Algorithm is described to optimise the order of the components within the DSM with the focus of minimising the value of the clustering criterion to identify the most significant component groupings (modules) within the product structure. The second stage utilises a 'Module Strength Indicator' (MSI) function to determine a value representative of the degree of modularity of the component groupings. The application of this function to the DSM produces a 'Module Structure Matrix' (MSM) depicting the relative modularity of available component groupings within it. The approach enabled the identification of hierarchical modularity in the product structure without the requirement for any additional domain specific knowledge within the system. The system supports design by providing mechanisms to explicitly represent and utilise component and dependency knowledge to facilitate the nontrivial task of determining near-optimal component modules and representing product modularity

A model-based approach for designing cost-effective compensation payments for conservation of endangered species in real landscapes

An approach is present which integrates an economic and an ecological model for designing cost-effective compensation payments for conservation of endangered species in real landscapes. The approach is used to develop a cost-effective compensation payment scheme for conservation of an endangered butterfly species (Maculinea teleius) protected by the EU Habitats Directive in the region of Landau, Germany. The economic model determines the costs of relevant conservation measures mowing meadows at different times and frequencies - and the ecological model quantifies the effects of these mowing regimes on the butterfly population. By comparing the ecological effects of different mowing regimes, the cost-effective regime and the corresponding payments are determined as a function of the conservation budget. The results of the case study are used to analyse the effect of metapopulation dynamics on the cost-effectiveness of compensation payment schemes, to evaluate an existing scheme in the region of Landau and to draw conclusions for the institutional design of payment schemes. --Conservation,biodiversity,metapopulation,cost-effectiveness,ecological-economic modelling

Larch Status A

LARCH is a model that is used by the Netherlands Environmental Assessment Agency (PBL) for ex-ante and ex-post evaluations of Dutch nature policies. LARCH generates the potential habitat networks of a species. LARCH will not predict the actual distribution of a specie

Isolation and identification of a male-produced aggregation-sex pheromone for the velvet longhorned beetle, Trichoferus campestris.

The velvet longhorned beetle, Trichoferus campestris (Faldermann) ("VLB"; Coleoptera: Cerambycidae), is native to eastern Asia where it infests and damages a wide range of deciduous and coniferous tree species, including orchard and timber species. Immature stages of VLB are transported to new countries via international commerce, and populations have established outside the native range of the species. Here, we show that identification of pheromones of invasive pest species can be expedited by knowledge of the semiochemistry of related taxa. Histological sectioning revealed subcuticular, male-specific prothoracic glands connected to pits in the cuticle, which, in related species, are diagnostic for production of male-produced aggregation-sex pheromones, usually characterized by 2,3-alkanediol/hydroxyketone structural motifs. However, in preliminary field bioassays, beetles were not attracted by any known cerambycid pheromones. Subsequently, we identified a novel variant of the hydroxyketone motif ("trichoferone") from headspace volatiles of males. In field bioassays, synthetic trichoferone was more attractive to both sexes of VLB than previously developed high-release-rate ethanol lures, and attraction was strongly female biased. This study demonstrated the utility of the prothoracic gland trait for predicting pheromone use in cerambycid species in the subfamily Cerambycinae, and that identification of pheromones of novel species can be expedited by knowledge of pheromones of related species. Trichoferone should prove to be a valuable tool for detection of VLB in regions where the beetle is or may become established

Modeling Routines and Organizational Learning. A Discussion of the State-of-the-Art

This paper presents a critical overview of some recent attempts at building formal models of organizations as information-processing and problem-solving entities. We distinguish between two classes of models according to the different objects of analysis. The first class includes models mainly addressing information processing and learning and analyzes the relations between the structure of information flows, learning patterns, and organizational performances. The second class focuses on the relationship between the division of cognitive labor and search processes in some problem-solving space, addressing more directly the notion of organizations as repositories of problem-solving knowledge. Here the objects of analysis are the problem-solving procedures which the organization embodies. The results begin to highlight important comparative properties regarding the impact on problem-solving efficiency and learning of different forms of hierarchical governance, the dangers of lock-in associated with specific forms of adaptive learning, the relative role of “online” vs. “offline” learning, the impact of the “cognitive maps” which organizations embody, the possible trade-offs between accuracy and speed of convergence associated with different “decomposition schemes”. We argue that these are important formal tools towards the development of a comparative institutional analysis addressing the distinct properties of different forms of organization and accumulation of knowledge.Division of labor, Mental models, Problem-solving, Problem decomposition.

Blight-MOP: Development of a systems approach for the management of late blight (caused by Phytophthora infestans) in EU organic potato production

Blight-MOP Late blight (caused by Phytophthora infestans) is the most devastating fungal disease affecting organic (and conventional) potato production in the EU. It kills the foliage and usually results in losses of yield which can be very large when infection is severe and occurs early in the season. The disease may be transmitted to the tubers which become unmarketable and these can lead to complete deterioration of the stored crop if put into storage with healthy tubers. To a great extent, conventional production systems rely upon frequent applications of synthetic fungicides with different modes of action for late blight control, but this is seldom completely successful. However, in organic systems, the availability of chemical fungicides is currently restricted to those which are ‘considered to be traditional organic farming practices’: these include copper hydroxide, copper oxychloride (tribasic), copper sulphate and cuprous oxide that have a protectant action and are reasonably effective. Their use is restricted by national legislation and organic certifying authorities and pressure has been mounting to withdraw them not only because of possible adverse effects on wildlife, the environment and human health but also their incompatibility with organic production principles. This led to a proposed ban on the use of copper fungicides for control of late blight in organic farming in the EU from March 2002 which had potentially serious implications for the potato crop. The resultant losses of yield and hence income in the absence of copper-based fungicide sprays were expected to threaten the economic viability of both organic potato enterprises and/or whole organic farming businesses in many areas of the EU in the medium to long term until effective, alternative methods are developed. In the meantime, two major approaches were adopted. One was to set a limit to the amount of copperbased fungicides permitted for application: until 31 December 2005, the maximum application was restricted to 8kg of elemental copper/ha/year for annual crops, declining to 6kg/ha/year from 1 January 2006 (but this could be changed at any time in the light of developments in viable alternatives or should there be proposals for withdrawal under the EC Review programme for existing active substances). Another was to promote further research to identify and develop effective alternative late blight control methods and strategies without the undesirable effects associated with copper-based fungicides. The Blight-MOP project – ‘Development of a systems approach for late Blight (caused by Phytophthora infestans) Management in EU Organic Production systems’ was initiated in March 2001 to achieve this aim and maintain yield and quality and hence commercial viability of organic potato crops without the use of copper fungicides. Such an approach involves integrated use of (i) resistant varieties (ii) existing agronomic strategies (iii) alternative treatments that can replace synthetic and copper-based fungicides (iv) use of existing blight forecasting systems to optimise control treatments and to maximise synergistic interactions between (i), (ii), (iii) and (iv). The specific objectives were to: 1. Assess the socio-economic impact of late blight and ‘state-of-the-art’ blight management practices in EU organic potato production systems 2. Assess varietal performance in organic production systems in different EU regions and interactions with local blight populations 3. Develop within field diversification strategies to prevent/delay blight epidemics 4. Optimise agronomic strategies for the management of late blight 5. Develop alternative control treatments to copper-based fungicides that comply with organic farming standards 6. Evaluate novel application and formulation strategies for copper- free/alternative and copper-based late blight treatments 7. Integrate optimised resistance management, diversification, agronomic and alternative control treatment strategies into existing organic potato management systems. To pursue these objectives, experiments were conducted over 4 seasons from 2001 to 2004 under organic cropping system conditions in seven countries (Denmark, France, Germany, Netherlands, Norway, Switzerland and United Kingdom) spanning a wide range of aerial, soil, production and marketing environments. The rate and severity of the late blight epidemics in 2001, 2002 and 2004 gave a rigorous test of the different components of the integrated management system which gave broadly similar effects in the three years. In 2003, the very hot, dry summer (and August in particular) severely restricted the disease making it difficult to evaluate the efficacy of treatments in some regions, but in others where infection did occur the general trends were similar to those observed in other years

Dilettante, Venturesome, Tory and Crafts: Drivers of Performance Among Taxonomic Groups

Empirical research has failed to cumulate into a coherent taxonomy of small firms. This may be because the method adapted from biology by Bill McKelvey has almost never been adopted. His approach calls for extensive variables and a focused sample of organizations, contrary to most empirical studies, which are specialized. Comparing general and special purpose approaches, we find some of the latter have more explanatory power than others and that general purpose taxonomies have the greatest explanatory power. Examining performance, we find the types do not display significantly different levels of performance but they display highly varied drivers of performance