Complex Langevin dynamics for dynamical QCD at nonzero chemical potential: a comparison with multi-parameter reweighting

We study lattice QCD at non-vanishing chemical potential using the complex Langevin equation. We compare the results with multi-parameter reweighting both from $\mu=0$ and phase quenched ensembles. We find a good agreement for lattice spacings below $\approx$0.15 fm. On coarser lattices the complex Langevin approach breaks down. Four flavors of staggered fermions are used on $N_t=4, 6$ and 8 lattices. For one ensemble we also use two flavors to investigate the effects of rooting.Comment: 10 pages, 11 figures, PRD version, minor change

Anomalies and discrete chiral symmetries

The quantum anomaly that breaks the U(1) axial symmetry of massless multi-flavored QCD leaves behind a discrete flavor-singlet chiral invariance. With massive quarks, this residual symmetry has a close connection with the strong CP-violating parameter theta. One result is that if the lightest quarks are degenerate, then a first order transition will occur when theta passes through pi. The resulting framework helps clarify when the rooting prescription for extrapolating in the number of flavors is valid.Comment: 12 pages, 7 figures. Contribution to the International Workshop on QCD Green's Functions, Confinement and Phenomenology September 7-11, 2009, ECT Trento, Italy. Revised version adds reference

EU-Rotate_N – a decision support system – to predict environmental and economic consequences of the management of nitrogen fertiliser in crop rotations

A model has been developed which assesses the economic and environmental performance of crop rotations, in both conventional and organic cropping, for over 70 arable and horticultural crops, and a wide range of growing conditions in Europe. The model, though originally based on the N_ABLE model, has been completely rewritten and contains new routines to simulate root development, the mineralisation and release of nitrogen (N) from soil organic matter and crop residues, and water dynamics in soil. New routines have been added to estimate the effects of sub-optimal rates of N and spacing on the marketable outputs and gross margins. The model provides a mechanism for generating scenarios to represent a range of differing crop and fertiliser management strategies which can be used to evaluate their effects on yield, gross margin and losses of nitrogen through leaching. Such testing has revealed that nitrogen management can be improved and that there is potential to increase gross margins whilst reducing nitrogen losses

Overwinter transplant production for extended season organic cropping (OF 0144)

The objectives of this project (Defra project OF0144), lead by EFRC, were to: • identify acceptable organic fungicide products to control mildew in transplant production • produce integrated organic transplant production systems for brassica, allium and lettuce over the autumn and winter period by identifying optimum cell/block sizes in relation to nutrient requirements and sources, growing media formulation, and supplementary feeding and watering • evaluate developed transplant production protocols during the winter period • undertake technology transfer and dissemination of the results Results: Protocols were tested for a range of crop species and varieties, growing media, cell size and feeding regimes over the three seasons under experimental and commercial conditions. It is possible to produce transplants of a suitable quality over the winter period although propagation time is generally longer than at more favourable times of year. With respect to identifying acceptable fungicide products • a range of fungicidal products was identified including L-Carvone, Mycosin, fennel and clove oils that showed potential in controlling mildew on a range of crop species. However the work also raised the question of the suitability of the use of such materials in organic systems which has not been resolved. • work on spectral filters found no benefits to their use in transplant production • cell size has minimal effect on disease spread As far as integrated organic transplant production systems are concerned: • production time was longer overwinter than in spring • lettuce was relatively easy to produce in a range of media and block sizes with no supplementary feed being necessary • similarly cabbage was relatively easy to produce although feeding was required • cauliflower was produced using smaller cell size and full nutrient compos

Characterizing temporary hydrological regimes at a European scale

Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios

Response of Root Properties to Tripartite Symbiosis between Lucerne (Medicago sativa L.), Rhizobia and Mycorrhiza Under Dry Organic Farming Conditions

It is generally considered that root turnover is a major contributor to organic matter and mineral nutrient cycles in organic managed agroecosystems. Approach: This study designed to investigate whether microbial activity could affect on root properties of lucerne in an organically managed field under dry weather conditions. The trial was laid out as a factorial experiment in the fields of the University of Natural Resources and Applied Life Sciences, Vienna-Austria at Raasdorf in 2007. The experimental factors of Sinorhizobium meliloti and arbuscular mycorrhiza (AM) including Glomus etunicatum, G. intraradices and G. claroideum and irrigation levels were tested. Results: Results showed that increasing water deficit affected root dry weigh, specific root mass and root length significantly at 1% level and co-inoculation of rhizobium and mycorrhiza with irrigation could increase all root parameters. Data’s of variance analysis for mycorrhizal colonization showed that main effect of using mycorrhiza had significant effects on root parameters at 5% and 1% probability level in first and second harvest, respectively. Results of mean comparisons by Duncan’s multiple range test showed that mycorrhizal colonization was higher in the inoculated treatments by rhizobium , mycorrhiza and irrigated plots in both harvests. Double interaction of mycorrhiza and irrigation was higher in both harvests (37.05% and 65.73%, respectively). Conclusion: Hence, it can be suggested that the tripartite symbiosis of S. meliloti, AM and lucerne can improve the performance of lucerne in organic farming and under dry conditions. Such traits could be incorporated into breeding programs to improve drought tolerance especially in organic fields

Characterizing temporary hydrological regimes at a European scale

Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios