The didactic value of linking models: experiences from the LEI model funnel

The complexity of agri-environmental economic issues is such that a model that is fully consistent at all levels of aggregation and all type of questions to be addressed is not available at the Agricultural Economics Research Institute in the Hague LEI. Such a model is probably also not feasible. At LEI this problem is solved by linking models at different scales of analysis: global economic, national economy-wide, regional agricultural, national spatial and farm levels. This linked model system enlarges scope and consistency of the analysis. The goal of the model linking, however, is not a full integration and, ultimately, simultaneous optimization of the models. Therefore, the different models of the LEI model funnel are often rather loosely linked. Hence, it is not surprising that the models sometimes produce different results even for the shared variables. This article describes the difficulties to share and exchange information between different models and identifies possible solutions which aim at a more consistent analysis along the models combined at LEI while maintaining the diversity of modelling approaches.economic models, combined models, quantitative policy analysis, Agricultural and Food Policy, Research Methods/ Statistical Methods,

Future of European agriculture after the Health Check

This paper identifies major future trends and driving factors and perspectives and challenges resulting from them for European agriculture and food sectors until the year 2020. The focus of the paper is an analysis of key driving forces and the provision of a well developed reference scenario under the assumption of continued CAP reform and taking into account the framework discussions in the Doha Development Round. To assess the impact of policies the paper also examines a liberalisation (no support) and regionalization (maximum support) scenario. In terms of policy options the paper shows that the structural change process in agriculture (measured in terms of agricultural share in GDP) is a long-term process that continues with or without policy changes. The EU is facing an increasing diversity of structure and structural adjustment. The livestock sector (especially cattle) faces important challenges and restructuring. Alternative policy settings may not produce very different effect on the overall production as factor markets adjust. However, the regional impact on the environment and on the number of farms may prove to be more significant.economic modelling, future, CAP policy options, structural change, Agricultural and Food Policy,

SCENAR2020: Future of European Agriculture under Different Policy Options, the economic modelling framework

This paper identifies major future trends and driving factors and perspectives and challenges resulting from them for European agriculture and food sectors until the year 2020. The focus of the paper is an analysis of key driving forces and the provision of a well developed reference scenario under the assumption of continued CAP reform and taking into account the framework discussions in the Doha Development Round. To assess the impact of policies the paper also examines a liberalisation (no support) and regionalisation (max support) scenario. In terms of policy options the paper shows that structural change process in agriculture is a long-term process that continues with or without policy changes. EU is facing an increasing diversity of structure and structural adjustment. The livestock sector faces important challenges and restructuring. Alternative policy settings may not produce very different effect on the overall production. However, the regional impact may prove to be more significant.Economic Modelling, Future, CAP Policy Options, Structural Change, Agricultural and Food Policy, International Relations/Trade, Livestock Production/Industries,

Competitiveness in the Food Industry: a CGE Modelling Approach to assess Foreign Direct Investment in Transition Countries

For transition countries, the food industry sector is a key industry in terms of output and employment shares. As a competitive sector that receives substantial foreign direct investments (FDI), it plays an important role as an element in the process of integration in the European and world market. The GLOBE Computable General Equilibrium model is applied to analyse scenarios of alternative development pathways of the food industry sector, taking into account the impact of FDI in the European food industry. The scenario analyses of this study identify that with an enhanced attraction of FDI in the food processing industries in the New Member States (NMS) the integration of the agri-food sectors in the NMS into the Single European Market will become even stronger.Food industry, foreign direct investment, CGE, transition countries, Agribusiness, International Relations/Trade,

Preeclampsia is associated with compromized maternal synthesis of long chain polyunsaturated fatty acids leading to offspring deficiency

Obesity and excessive lipolysis are implicated in preeclampsia (PE). Intrauterine growth restriction is associated with low maternal body mass index and decreased lipolysis. Our aim was to assess how maternal and offspring fatty acid metabolism is altered in mothers in the third trimester of pregnancy with PE (n=62) or intrauterine growth restriction (n=23) compared with healthy pregnancies (n=164). Markers of lipid metabolism and erythrocyte fatty acid concentrations were measured. Maternal adipose tissue fatty acid composition and mRNA expression of adipose tissue fatty acid–metabolizing enzymes and placental fatty acid transporters were compared. Mothers with PE had higher plasma triglyceride (21%, P<0.001) and nonesterified fatty acid (50%, P<0.001) concentrations than controls. Concentrations of major n−6 and n−3 long-chain polyunsaturated fatty acids in erythrocytes were 23% to 60% lower (all P<0.005) in PE and intrauterine growth restriction mothers and offspring compared with controls. Subcutaneous adipose tissue Δ−5 and Δ−6 desaturase and very long-chain fatty acid elongase mRNA expression was lower in PE than controls (respectively, mean [SD] control 3.38 [2.96] versus PE 1.83 [1.91], P=0.030; 3.33 [2.25] versus 1.03 [0.96], P<0.001; 0.40 [0.81] versus 0.00 [0.00], P=0.038 expression relative to control gene [square root]). Low maternal and fetal long-chain polyunsaturated fatty acid concentrations in PE may be the result of decreased maternal synthesis

The Self Model and the Conception of Biological Identity in Immunology

The self/non-self model, first proposed by F.M. Burnet, has dominated immunology for sixty years now. According to this model, any foreign element will trigger an immune reaction in an organism, whereas endogenous elements will not, in normal circumstances, induce an immune reaction. In this paper we show that the self/non-self model is no longer an appropriate explanation of experimental data in immunology, and that this inadequacy may be rooted in an excessively strong metaphysical conception of biological identity. We suggest that another hypothesis, one based on the notion of continuity, gives a better account of immune phenomena. Finally, we underscore the mapping between this metaphysical deflation from self to continuity in immunology and the philosophical debate between substantialism and empiricism about identity

Growth factors for clinical-scale expansion of human articular chondrocytes : Relevance for automated bioreactor systems

The expansion of chondrocytes in automated bioreactors for clinical use requires that a relevant number of cells be generated, starting from variable initial seeding densities in one passage and using autologous serum. We investigated whether the growth factor combination transforming growth factor beta 1/fibroblast growth factor 2/platelet-derived growth factor BB (TFP), recently shown to enhance the proliferation capacity of human articular chondrocytes (HACs), allows the efficiency of chondrocyte use to be increased at different seeding densities and percentages of human serum (HS). HACs were seeded at 1,000, 5,000, and 10,000 celIS/cm(2) in medium containing 10 bovine serum or 10,000 cells/cm(2) with 1 chondrogenic capacity of post-expanded HACs was then assessed in pellet cultures. Expansion with TFP allowed a sufficient number of HACs to be obtained in one passage even at the lowest seeding density and HS percentage and variability in cartilage-forming capacity of HACs expanded under the different conditions to be reduced. Instead, larger variations and insufficient yields were found in the absence of TFP. By allowing large numbers of cells to be obtained, starting from a wide range of initial seeding densities and HS percentages, the use of TFP may represent a viable solution for the efficient expansion of HACs and addresses constraints of automated clinical bioreactor systems

Inclusive particle production at HERA: Higher-order QCD corrections to the resolved quasi-real photon contribution

We calculate in next-to-leading order inclusive cross sections of single-particle production via resolved photons in $ep$ collisions at HERA. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with first experimental data from the H1 Collaboration at HERA.Comment: 11 pages with 15 uuencoded PS figures. Preprint DESY 93-03

Stromal targets for fluorescent-guided oncologic surgery

Pre-operative imaging techniques are essential for tumor detection and diagnosis, but offer limited help during surgery. Recently, the applicability of imaging during oncologic surgery has been recognized, using near-infrared fluorescent dyes conjugated to targeting antibodies, peptides, or other vehicles. Image-guided oncologic surgery (IGOS) assists the surgeFon to distinguish tumor from normal tissue during operation, and can aid in recognizing vital structures. IGOS relies on an optimized combination of a dedicated fluorescent camera system and specific probes for targeting. IGOS probes for clinical use are not widely available yet, but numerous pre-clinical studies have been published and clinical trials are being established or prepared. Most of the investigated probes are based on antibodies or peptides against proteins on the membranes of malignant cells, whereas others are directed against stromal cells. Targeting stroma cells for IGOS has several advantages. Besides the high stromal content in more aggressive tumor types, the stroma is often primarily located at the periphery/invasive front of the tumor, which makes stromal targets particularly suited for imaging purposes. Moreover, because stroma up-regulation is a physiological reaction, most proteins to be targeted on these cells are “universal” and not derived from a specific genetic variation, as is the case with many upregulated proteins on malignant cancer cells