Transparency in the Pork Supply Chain: Comparing China and The Netherlands

We present a research plan to assess the value of transparency by comparing pork supply chains in The Netherlands and China.We assume that chain performance depends on chain configuration, which depends on societal context and its associated quality control institutions. We define chain configuration in terms of structure and transparency. In order to be able to assess the influence of societal context and its quality control institutions on chain configuration and performance, we compare two countries that have very different societies. Ultimately, our goal is to be able to indicate whether a certain chain configuration suits all, or whether chain configuration should be tailored to societal context.Pork supply chain, societal context, transparency, information exchange, chain configuration, Agribusiness, Industrial Organization,

Two-dimensional global manifolds of vector fields

We describe an efficient algorithm for computing two-dimensional stable and unstable manifolds of three-dimensional vector fields. Larger and larger pieces of a manifold are grown until a sufficiently long piece is obtained. This allows one to study manifolds geometrically and obtain important features of dynamical behavior. For illustration, we compute the stable manifold of the origin spiralling into the Lorenz attractor, and an unstable manifold in zeta(3)-model converging to an attracting limit cycle

Een bijdrage tot de optimalisering van de voeding op grote melkveebedrijven

The need of a control of costs and production begins to make itself more strongly in modem developing farm units in dairy husbandry. It has been checked what costs are most important in dairy farming. The cost of roughages and concentrates for the herd amounts to approximately 70% of the net cost price per kg of milk. This percentage is practically independent of the number of cattle per hectare. If the feeding-costs per kind of fodder (roughages and concentrates) and the yield of the herd can be controlled, the farmer controls two major parameters in his farm management. The costs per SE (Starch Equivalent) per kind of roughage have been calculated on the basis of various costfactors both based on work done by the farmer himself and on contractor's tariffs (table 12).Three dairy-farms were controlled for two years in order to examine the results of a method of control. The yield of milk was estimated per month on the basis of the expected standard-cow-production and the expected number of standard-cows per 10 days. It appeared that these estimations were rather accurate. For selection in the herd estimations were made of the lactationproductions (305 days) based on 60, 100, 160 and 200 days of lactation after calving. It appeared that these estimations based on the standard values of the cows were very accurate. The correlation-coefficients between the estimations and the real yields were very high. As a result of these high correlations it should be considered to restrict the milk-sampling (periods of 3 weeks) in milk-recording to 3 or 5 samples in the beginning of the lactation. This would save costs considerably. Besides the milk-yield, estimations were also made of the need of SE per month for each farm, and the supply of SE from roughages and the necessary SE from concentrated fodder.For the grazing-period a method was applied to calculate the need of concentrates by means of the standard-values of individual cows and the standard-cow-production of the herd. This method was necessary, because in the grazing period the low productive and dry cows get more SE from grass than they need for maintenance and production. It appeared that the estimation of the need of SE was comparable with other methods of estimation. Every month the calculated quantity of concentrates was compared with the quantity really needed. It happened that there were months with great deviations, mainly caused by an adaptation to changing circumstances (the weather, the quantity of grass available, the quality of roughages) and giving too much and sometimes too little concentrated fodder. With the prices calculated (level 1975) for roughages, the prices of concentrates and the estimated prices of milk a calculation was made of the feeding-income per month (milk-money minus feedingcosts). It appeared that the costs per kg of milk, based on the costs calculated showed great differences between the summer and the winter period. The estimation of the net margin based on the prices of table 12 proved to be wrong.The real costs per SE were higher than estimated. On the basis of the real costs calculations were made of the costs per SE and per cost-factor for several roughages. Rises in wages and the way of using grassland (percentage of cutting) proved to be important causes of increasing costs.For the system applied the farmer needs the following information:- the composition of his dairy herd- the feeding-strategy applied- the expected standard-cow productionOne can calculate the milk-production from the quick method for the calculation of the number of standard-cows and the expected standard-cow production. Then it is easy to calculate the need of SE for maintenance and production. The total need of SE can be met by the supply of roughages and the concentrates to be given. In this way a budget can be made that should later be compared with the real situation.</p

Bifurcations of the global stable set of a planar endomorphism near a cusp singularity

The dynamics of a system defined by an endomorphism is essentially different from that of a system defined by a diffeomorphism due to interaction of invariant objects with the so-called critical locus. A planar endomorphism typically folds the phase space along curves J0 where the Jacobian of the map is singular. The critical locus, denoted J1, is the image of J0. It is often only piecewise smooth due to the presence of isolated cusp points that are persistent under perturbation. We investigate what happens when the stable set Ws of a fixed point or periodic orbit interacts with J1 near such a cusp point C1. Our approach is in the spirit of bifurcation theory, and we classify the different unfoldings of the codimension-two singularity where the curve Ws is tangent to J1 exactly at C1. The analysis uses a local normal-form setup that identifies the possible local phase portraits. These local phase portraits give rise to different global manifestations of the behavior as organized by five different global bifurcation diagrams. © 2008 World Scientific Publishing Company

Clinical implications of the oncometabolite succinate in SDHx-mutation carriers

Succinate dehydrogenase (SDH) mutations lead to the accumulation of succinate, which acts as an oncometabolite. Germline SDHx mutations predispose to paraganglioma (PGL) and pheochromocytoma (PCC), as well as to renal cell carcinoma and gastro-intestinal stromal tumors. The SDHx genes were the first tumor suppressor genes discovered which encode for a mitochondrial enzyme, thereby supporting Otto Warburg's hypothesis in 1926 that a direct link existed between mitochondrial dysfunction and cancer. Accumulation of succinate is the hallmark of tumorigenesis in PGL and PCC. Succinate accumulation inhibits several α-ketoglutarate dioxygenases, thereby inducing the pseudohypoxia pathway and causing epigenetic changes. Moreover, SDH loss as a consequence of SDHx mutations can lead to reprogramming of cell metabolism. Metabolomics can be used as a diagnostic tool, as succinate and other metabolites can be measured in tumor tissue, plasma and urine with different techniques. Furthermore, these pathophysiological characteristics provide insight into therapeutic targets for metastatic disease. This review provides an overview of the pathophysiology and clinical implications of oncometabolite succinate in SDHx mutations

Development and evaluation of a novel contamination device that targets multiple life-stages of Aedes aegypti.

BACKGROUND: The increasing global threat of Dengue demands new and easily applicable vector control methods. Ovitraps provide a low-tech and inexpensive means to combat Dengue vectors. Here we describe the development and optimization process of a novel contamination device that targets multiple life-stages of the Aedes aegypti mosquito. Special focus is directed to the diverse array of control agents deployed in this trap, covering adulticidal, larvicidal and autodissemination impacts. METHODS: Different trap prototypes and their parts are described, including a floater to contaminate alighting gravid mosquitoes. The attractiveness of the trap, different odor lures and floater design were studied using fluorescent powder adhering to mosquito legs and via choice tests. We demonstrate the mosquitocidal impacts of the control agents: a combination of the larvicide pyriproxyfen and the adulticidal fungus Beauveria bassiana. The impact of pyriproxyfen was determined in free-flight dissemination experiments. The effect on larval development inside the trap and in surrounding breeding sites was measured, as well as survival impacts on recaptured adults. RESULTS: The developmental process resulted in a design that consists of a black 3 Liter water-filled container with a ring-shaped floater supporting vertically placed gauze dusted with the control agents. On average, 90% of the mosquitoes in the fluorescence experiments made contact with the gauze on the floater. Studies on attractants indicated that a yeast-containing tablet was the most attractive odor lure. Furthermore, the fungus Beauveria bassiana was able to significantly increase mortality of the free-flying adults compared to controls. Dissemination of pyriproxyfen led to >90% larval mortality in alternative breeding sites and 100% larval mortality in the trap itself, against a control mortality of around 5%. CONCLUSION: This ovitrap is a promising new tool in the battle against Dengue. It has proven to be attractive to Aedes aegypti mosquitoes and effective in contaminating these with Beauveria bassiana. Furthermore, we show that the larvicide pyriproxyfen is successfully disseminated to breeding sites close to the trap. Its low production and operating costs enable large scale deployment in Dengue-affected locations

The effect of depth on the morphology, bacterial clearance, and respiration of the mediterranean sponge chondrosia reniformis (Nardo, 1847)

To support the successful application of sponges for water purification and collagen production, we evaluated the effect of depth on sponge morphology, growth, physiology, and functioning. Specimens of Eastern Mediterranean populations of the sponge Chondrosia reniformis (Nardo, 1847) (Demospongiae, Chondrosiida, Chondrosiidae) were reciprocally transplanted between 5 and 20 m depth within the KaŠ-Kekova Marine Reserve Area. Control sponges at 5 m had fewer but larger oscula than their conspecifics at 20 m, and a significant inverse relationship between the osculum density and size was found in C. reniformis specimens growing along a natural depth gradient. Sponges transplanted from 20 to 5 m altered their morphology to match the 5 m control sponges, producing fewer but larger oscula, whereas explants transplanted from 5 to 20 m did not show a reciprocal morphological plasticity. Despite the changes in morphology, the clearance, respiration, and growth rates were comparable among all the experimental groups. This indicates that depth-induced morphological changes do not affect the overall performance of the sponges. Hence, the potential for the growth and bioremediation of C. reniformis in mariculture is not likely to change with varying culture depth. The collagen content, however, was higher in shallow water C. reniformis compared to deeper-growing sponges, which requires further study to optimize collagen production.This research was executed within the Connected Circularity program, financed by strategic funding of Wageningen University and Research and the knowledge base of the Ministry of Agriculture, Nature, and FoodQuality (KB40), and was part of the ERA-NET project Biogenink (project 4195), funded by the EuropeanCommission in conjunction with the Dutch Science Foundation NWO and the Portuguese Foundation for Science and Technology (FCT) (project M-ERA-NET-2/0022/2016)

Onderzoekplan 1990

Voor een deel wordt dit bepaald door de voortzetting van het bestaande onderzoek. Voor ongeveer 30 % van de totale capaciteit kan nieuw onderzoek in het plan worden opgenomen