Stabilization and plant uptake of N from 15N-labelled pea residue 16.5 years after incorporation in soil

The decline of N from 15N-labelled mature pea residues was followed in unplanted soil over 16.5 yr. Eight years after residue incorporation, 24% of the residue 15N input was still present in the soil and, after 16.5 yr, 16% of the residue 15N input remained. A double exponential model successfully described the decay of N from 15N-labelled pea residues. The total residual 15N declined with average decay constants of 1.45 yr−1 for the 30 d to 1 yr period and of 0.07 yr−1 for the 1–16 yr period. Sixteen years following incorporation of the residues, indicator plants growing in residues-amended soils were obtaining 1.7% of their N from residue N. This is, to our knowledge, the longest study on decay of N in soils from 15N-labelled crop residues. The current study thus provides a unique data set for our empirical understanding of N-dynamics in agricultural systems, which is a prerequisite to parameterize and validate N-simulation models

Developing Energy Plants for Biofuels Production may Comply to Organic Principles

Biofuels are the only source of renewable environmentally friendly fuel currently suitable for road transport without any negative traits associated with traditional biodiesel or other green energy alternatives. The combustion of petrol and diesel produces many different types of local air pollutants, but the use of biofuels may result in the reductions in emissions of greenhouse gas carbon dioxide up to 70%. Impacts on land use require careful planning to maximise the gains and minimise the losses. The role of biofuels in organic farming will solve three significant problems: 1) waste will become valuable resources; 2) low quality forage products can be utilized for biofuels and thus get value-added; and 3) the trafficable damage on soil fertilities will be reduced by the minimized recirculation rate of bulky watery waste products

Critical behavior of an absorbing phase transition in an interacting monomer-dimer model

We study a monomer-dimer model with repulsive interactions between the same species in one dimension. With infinitely strong interactions the model exhibits a continuous transition from a reactive phase to an inactive phase with two equivalent absorbing states. Static and dynamic Monte Carlo simulations show that the critical behavior at the transition is different from the conventional directed percolation universality class but is consistent with that of the models with the mass conservation of modulo 2. The values of static and dynamic critical exponents are compared with those of other models. We also show that the directed percolation universality class is recovered when a symmetry-breaking field is introduced.Comment: 9 pages, latex, 1 figure (one PS figure file upon request) (appear in Physica A (1995): Proceeding of Statphys-Taipei-1995

Proteomic analysis of the Mycocentrospora acerina-carrot interaction during storage

During post harvest storage, a large proportion of carrots (more than 50%) may have to be discarded due to the development of liquorice rot caused by Mycocentrospora acerina. This fungus is soil borne and brought into the store in to soil adhering to the root. Liquorice rot development is mainly related to physiological or structural resistance of carrot, therefore the control of this storage disease is based on cultural practices and storage conditions. It is believed that carrots at the beginning of storage can resist disease developments due to chemical defence mechanisms involving some proteins, peptides and secondary metabolites. The hypothesis is that proteome changes during storage of carrots are related to the susceptibility to M. acerina. During root-pathogen interactions, several genes have been reported to provide resistance against pathogens but only few proteins have been identified using proteomic approaches. Little is known about proteins involved during M. acerina - carrot interaction. The carrots used in this study are grown under two different agricultural practices (one conventional, one organic) in order to investigate the effect of the cropping system on the susceptibility to liquorice rot. We developed a bioassay for infection studies of M. acerina on conventional and organic carrots in order to determine the important time points of the infection process. Then the proteome is investigated at these different time points. The protocol for extraction of proteins has been improved so that it can be used to obtain an optimal recovery of proteins from both plant and pathogen on their own as well as from infected carrot roots. Proteomes of carrot and of M. acerina are characterized by two dimensional gel electrophoreses and the proteins whose synthesis varies significantly in the course of pathogen infection are identified by mass spectrometry (MALDI TOF-TOF)

Prevention of enteroxigenic Escherichia coli infections in pigs by dairy-based nutrition

Abstract Postweaning diarrhea (PWD) is a significant enteric disease causing considerable economic losses for the pig industry. Among several aetiological risk factors, enterotoxigenic Escherichia coli (ETEC) is considered to be a major cause. After being routinely used for several decades to control bacterial disease outbreaks in piglet, the use of antibiotics at subtherapeutic concentrations has been banned in the European Union because of the increasing prevalence of resistance to antibiotics in pigs. The removal of in-feed antibiotics from piglet diets has negative economic consequences as it dramatically increases the rate of morbidity and mortality due to ETEC as well as the use of antibiotics for therapeutic purposes. Other than subtherapeutic antibiotics, zinc oxide (ZnO) had been reported to ameliorate and/or prevent the development of PWD in piglets, but its excretion may have negative impacts on the environment. Thus, other alternatives that control ETEC infections in piglets postweaning will be of great advantage. A number of nutritional strategies have been proposed as alternative means of preventing ETEC infections, of which feeding dairy-based products to piglets could be one of such strategies. It is apparent that colostrums, milk and milk fractions such as whey and casein contain several biologically active compounds with anti-microbial and immunomodulatory properties. Recently, these dairy products and their isolated compounds such as lactoferrin and oligosaccharides have been employed as anti-infective agents against ETEC infections in iglets postweaning. The dairy by-products (e.g. whey or whey permeate) may also be fermented to further improve the anti-infective potential of the products. Overall, the anti-infective activities of dairy-based products against ETEC could be attributed to the improvement of the intestinal barrier functions, microbial ecosystem and immunity of the piglets. Keywords : Dairy-based product; Anti-microbial; Immunomodulation; Anti-infective; Enterotoxigenic Escherichia coli; Postweaning diarrhea; Pigle

Inverse Statistics in the Foreign Exchange Market

We investigate intra-day foreign exchange (FX) time series using the inverse statistic analysis developed in [1,2]. Specifically, we study the time-averaged distributions of waiting times needed to obtain a certain increase (decrease) $\rho$ in the price of an investment. The analysis is performed for the Deutsch mark (DM) against the $US for the full year of 1998, but similar results are obtained for the Japanese Yen against the$US. With high statistical significance, the presence of "resonance peaks" in the waiting time distributions is established. Such peaks are a consequence of the trading habits of the markets participants as they are not present in the corresponding tick (business) waiting time distributions. Furthermore, a new {\em stylized fact}, is observed for the waiting time distribution in the form of a power law Pdf. This result is achieved by rescaling of the physical waiting time by the corresponding tick time thereby partially removing scale dependent features of the market activity.Comment: 8 pages. Accepted Physica

Cavity basics

The fields in rectangular and circular waveguides are derived from Maxwell's equations by superposition of plane waves. Subsequently the results are applied to explain cavity modes. Interaction of the cavity modes with a charged particle beam leads to the fundamental parameters used to describe the performance of accelerating cavities. Finally an introduction to multi-gap cavities is given by the example of travelling-wave structures.Comment: 17 pages, contribution to the CAS - CERN Accelerator School: Specialised Course on RF for Accelerators; 8 - 17 Jun 2010, Ebeltoft, Denmar