New results in rho^0 meson physics

We compare the predictions of a range of existing models based on the Vector Meson Dominance hypothesis with data on e^+ e^- -> pi^+ pi^$ and e^+ e^- -> mu^+ mu^- cross-sections and the phase and near-threshold behavior of the timelike pion form factor, with the aim of determining which (if any) of these models is capable of providing an accurate representation of the full range of experimental data. We find that, of the models considered, only that proposed by Bando et al. is able to consistently account for all information, provided one allows its parameter "a" to vary from the usual value of 2 to 2.4. Our fit with this model gives a point-like coupling (gamma pi^+ \pi^-) of magnitude ~ -e/6, while the common formulation of VMD excludes such a term. The resulting values for the rho mass and pi^+ pi^- and e^+e^- partial widths as well as the branching ratio for the decay omega -> pi^+ pi^- obtained within the context of this model are consistent with previous results.Comment: 34 pages with 7 figures. Published version also available at http://link.springer.de/link/service/journals/10052/tocs/t8002002.ht

Electrical characterization of the soft breakdown failure mode in MgO layers

The soft breakdown (SBD) failure mode in 20 nm thick MgO dielectric layers grown on Si substrates was investigated. We show that during a constant voltage stress, charge trapping and progressive breakdown coexist, and that the degradation dynamics is captured by a power-law time dependence. We also show that the SBD current-voltage (I-V) characteristics follow the power-law model I = aVb typical of this conduction mechanism but in a wider voltage window than the one reported in the past for SiO2. The relationship between the magnitude of the current and the normalized differential conductance was analyzed

The development of systems of milk production and grazing management based on low stocking rates and very low artificial nitrogen inputs.

End of Project ReportThere is increasing pressure on to reduce nitrogen (N) inputs to agricultural production systems within the European Union. This three-year experiment examined the impact of lowering N-input/ha on milk output, carrying capacity and N losses. In Ireland, a dairy cow is classified as excreting 85 kg organic N per year. There were four treatments involving annual stocking rates and fertilizer N inputs as follows: (1) 2.5 cows/ha & 350 kg/ha (Intensive), (2) 2.5 cows/ha & 250 kg/ha (Moderate), (3) 2.1 cows/ha & 175 kg/ha (Extensive) and (4) 1.75 cows/ha & 80 kg/ha (Minimal). Swards were initially composed predominantly of perennial ryegrass and contained white clover. The primary aim was to supply sufficient pasture to meet the feed requirements of the lactating cows during the main grazing season. Subject to meeting this requirement the objective was to produce enough grass to meet winter-feed requirements as grass-silage. Production of grasssilage was indicative of carrying capacity. There were 18 cows per treatment each year. Concentrates fed were 595 kg/cow/year. There were no significant differences in yields (mean ± SEM kg/cow/year) of solids-corrected milk (6210 ± 97), fat (263 ± 4.4), protein (225 ± 3.3) and lactose (301 ± 5.2) between treatments combined over years. Silage production was sufficient to meet winter-feed requirements (i.e. 1.40 t DM/cow) on all treatments except Moderate, which was 0.87 of requirement. Measurement of soil mineral N concentrations indicated largest losses from Intensive during the winter. However, measurement of nitrate N in drainage water during the winter indicated low concentrations (mg/litre) from all treatments; 2.4 from Intensive, 2.0 from Mininal, 0.9 from Moderate and 0.9 from Extensive. The comparably high mean concentrations associated with Minimal were attributed to the high proportion of white clover in these swards and the breakdown of clover stolon releasing mineral N into the soil during the winter months. The main findings were: (1) No difference in milk output per cow even under low fertilizer N inputs (2) A relationship between requirement for fertiliser N and stocking rate along the line: Fertilizer N req. = (SR x 300) – (300 + background-N) Where SR is stocking rate in cows per ha and background N is the release of N from net mineralization of soil organic matter N. The average value for background-N is around 130 kg/ha. (3) Very high levels of productivity from grass + white clover swards receiving 80 kg N/ha/year with around 80% of the carrying capacity of the Intensive treatment. (4) Very low losses of nitrate-N in drainage water under organic N loads of up to 300 kg/ha. Losses of nitrate-N in drainage water accounted for less than 5% of N losses in the experiment except on the clover-system. It is likely that denitrification and losses of di-nitrogen (N2) and nitrous oxide (N2O) gasses were the main pathways for loss. This is consistent with the heavy wet imperfectly drained soils, high rainfall, intermittent soil saturation and the mild conditions experienced at Solohead

Symptomatic rubella re-infection in early pregnancy and subsequent delivery of an infected but minimally involved infant A case report

A case of serologically proven symptomatic rubella re-infection in early pregnancy in a healthy multigravida who had been successfully vaccinated is reported to illustrate that the risk to the fetus is considerably less than with primary infection. The infant was infected, as evidenced by specific IgM in cord blood, but had no stigmata of congenital rubella at birth. Growth retardation was apparent at 6 months and hearing loss, not necessarily due to rubella, was detected at 8 months. Rubella re-infection, which may now be distinguished serologically. by the urea degradation test from primary rubella, need not necessarily be an indication for termination of pregnancy

Vegetative propagation of dieback-tolerant Fraxinus excelsior on

book chapterThis publication is based on the work of Action FP1103 FRAXBACK, supported by COST (European Cooperation in Science and Technology)Ash trees which are tolerant to Hymenoscyphus fraxineus may be selected in all age classes among heavily infected populations. They may be produced also by controlled crossings of disease tolerant trees, because the genetic component of inheritance for disease tolerance is high. For mature and juvenile plant material, the deployment of disease tolerant genotypes could be potentially achieved by vegetatively propagating selected genotypes. We describe a system to vegetatively propagate selected ash genotypes and we discuss the prospects and options for using vegetative propagation on all age classes of trees. Mature trees were rejuvenated through the process of micropropagation to establish mother plants in large trays which were cut back repeatedly (hedged) to produce at least two crops of cuttings per year. The rooting capacity of ten genotypes was tested by a commercial nursery over a period of three years, to assess the feasibility of using hedged mother plants for efficient propagation. Commercial practise was to treat cuttings with 0.25% IBA, insert them in plug pots and maintain them covered with fine plastic within low plastic tunnels in a non heated greenhouse and without supplementary heating at the cutting base. In the first year, the mean rooting rate was 53 % for the first crop of cuttings and 35 % for the second. In the second and third years the rooting rates improved to over 80% for each crop of cuttings as experience was gained in handling the material. Rooting rate varied among the genotypes. We assessed the growth and development of micropropagated ash trees in the field from an observation clonal trial, consisting of four mature genotypes which had been established in 2002 in five replicate plots. The micropropagated trees were generally similar in height and dbh to seed derived control trees and developed normally. These observations are discussed in the context of using vegetative propagation as a tool in breeding and for the large scale deployment of ash with tolerance to H. fraxineus.European Cooperation in Science and Technolog