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

Preparing for a Pandemic: Spending Dynamics and Panic Buying during the COVID-19 First Wave

In times of heightened uncertainty, consumers face incentives to build up precautionary stocks of essential supplies. We study consumer spending dynamics during one such time, the first infection wave of the COVID-19 pandemic, using household scanner data covering fast-moving consumer goods in the United Kingdom. We document large increases in demand for storable products, such as food staples and household supplies, in the days before lockdown. Households in all socio-economic groups exhibit unusually high demand pre-lockdown, but there is a clear gradient, with the largest demand spikes for wealthier households. Although stories of people purchasing extreme amounts received a lot of attention, higher aggregate demand was mainly driven by more households than usual choosing to buy storable products, with only small increases in average quantities bought on a given trip. Temporary limits on the number of units per transaction, introduced following the demand spike, are therefore unlikely to lead to the avoidance of stock-outs

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

Coordination of tolerogenic immune responses by the commensal microbiota

All mammals are born ignorant to the existence of micro-organisms. Soon after birth, however, every mammal begins a lifelong association with a multitude of microbes that lay residence on the skin, mouth, vaginal mucosa and gastrointestinal (GI) tract. Approximately 500–1000 different species of microbes have highly evolved to occupy these bodily niches, with the highest density and diversity occurring within the intestine [1]. These organisms play a vital role in mammalian nutrient breakdown and provide resistance to colonization by pathogenic micro-organisms. More recently, however, studies have demonstrated that the microbiota can have a profound and long-lasting effect on the development of our immune system both inside and outside the intestine [2]. While our immune system has evolved to recognize and eradicate foreign entities, it tolerates the symbiotic micro-organisms of the intestine. How and why this tolerance occurs has remained unclear. Here we present evidence that the commensal microbes of the intestine actively induce tolerant responses from the host that coordinate healthy immune responses. Potentially, disruption of this dialogue between the host and microbe can lead to the development of autoimmune diseases such as inflammatory bowel disease (IBD), rheumatoid arthritis (RA), or Type I diabetes (TID). As a wealth of publications have focused on the impact of the microbiota on intestinal immune responses and IBD, this chapter will focus on the extra-intestinal impacts of the microbiota from development to disease and integrate the known mechanisms by which the microbiota is able to actively communicate with its host to promote health