3+1 dimensional Yang-Mills theory as a local theory of evolution of metrics on 3 manifolds

An explicit canonical transformation is constructed to relate the physical subspace of Yang-Mills theory to the phase space of the ADM variables of general relativity. This maps 3+1 dimensional Yang-Mills theory to local evolution of metrics on 3 manifolds.Comment: 7 pages, revte

Ggo-vrije veevoedergrondstoffen voor de melkveehouderij : borging, beschikbaarheid en kosten

Dit rapport bevat de resultaten van een studie naar de beschikbaarheid van ggo-vrije mengvoergrondstoffen (maïsglutenvoermeel en soja) voor de melkveehouderij in Nederland en in Europa. Daarnaast zijn de verschillende mogelijke borgingssystemen in beeld gebracht en is een inschatting gemaakt van de extra kosten van een Identity Preservation borgingssysteem. Ook is ingegaan op de vraag wie deze extra kosten zal gaan betalen. Het onderzoek is uitgevoerd in opdracht van het Productschap voor Zuivel

Assessment of recent outbreaks of Dickeya sp (syn. Erwinia chrysanthemi) slow wilt in potato crops in Israel

Suspected Dickeya sp. strains were obtained from potato plants and tubers collected from commercial plots. The disease was observed on crops of various cultivars grown from seed tubers imported from the Netherlands during the spring seasons of 2004-2006, with disease incidence of 2-30% ( 10% in average). In addition to typical wilting symptoms on the foliage, in cases of severe infection, progeny tubers were rotten in the soil. Six strains were characterised by biochemical, serological and PCR amplification. All tests verified the strains as Dickeya sp. The repPCR and the biochemical assays showed that the strains isolated from blackleg diseased plants in Israel were very similar, if not identical to strains isolated from Dutch seed potatoes, suggesting that the infection in Israel originated from the Dutch seed. The strains were distantly related to D. dianthicola strains, typically found in potatoes in Western Europe, and were similar to biovar 3 D. dadanti or D. zeae. This is the first time that the presence of biovar 3 strains in potato in the Netherlands is described. One of the strains was used for pathogenicity assays on potato cvs Nicola and Mondial. Symptoms appeared 2 to 3 days after stem inoculation, and 7 to 10 days after soil inoculation. The control plants treated with water, or plants inoculated with Pectobacterium carotovorum, did not develop any symptoms with either method of inoculation. The identity of Dickeya sp. and P. carotovorum re- isolated from inoculated plants was confirmed by PCR and ELISA

Vraaggestuurde ketens

This report by Animal Sciences Group, Agrotechnology & Food Innovations and LEI looks at demand pull in chains and aims to find an answer to the question: 'What can the government leave to market forces (under certain conditions) and what action does it need to take itself?' After a 'quick scan' of the existing literature, originating both from the Netherlands and else-where in the world, the literature on demand pull and transparency was explored more intensively and the gaps in the knowledge were indicated. Lastly, in the third phase, the research examined the purchasing behaviour of consumers and retailers in greater depth, for instance by means of interviews with buyers (retailers and bulk consumers) of fresh meat

Ketenpartijen over dierenwelzijn en een dierenwelzijnindex

Deze studie geeft een beeld van de behoeften, wensen, verwachtingen, randvoorwaarden en eisen van veehouders, veehandelaren, groothandelaren, be- en verwerkende bedrijven en NGO's met betrekking tot een dierenwelzijnindex. Daarnaast is aandacht besteed aan de rol van ketensamenwerking bij de introductie en implementatie van een dierenwelzijnindex. Deze informatie is van belang voor de ontwikkeling van een dierenwelzijnindex en voor de introductie ervan. This study presents a picture of the needs, wishes, expectations, conditions and requirements of livestock farmers, livestock dealers, wholesalers, treatment and processing industries and NGOs involved in introducing an animal welfare index. Attention is also paid to the role of chain cooperation in the introduction and implementation of an animal welfare index. This information is of relevance to the development and introduction of an animal welfare index

Kinetics and Jamming Coverage in a Random Sequential Adsorption of Polymer Chains

Using a highly efficient Monte Carlo algorithm, we are able to study the growth of coverage in a random sequential adsorption (RSA) of self-avoiding walk (SAW) chains for up to 10^{12} time steps on a square lattice. For the first time, the true jamming coverage (theta_J) is found to decay with the chain length (N) with a power-law theta_J propto N^{-0.1}. The growth of the coverage to its jamming limit can be described by a power-law, theta(t) approx theta_J -c/t^y with an effective exponent y which depends on the chain length, i.e., y = 0.50 for N=4 to y = 0.07 for N=30 with y -> 0 in the asymptotic limit N -> infinity.Comment: RevTeX, 5 pages inclduing figure