Molecular diagnostic methods can prevent unnecessary rejection of organic seed lots

In some years, large amounts of organic seed lots are discarded due to the presence of high levels of seed-borne diseases. In barley it is especially the presence of the fungal species Pyrenophora teres (barley net blotch) and P. graminea (barley leaf stripe), which causes rejection of seed lots. A real-time PCR method for detection and quantification of P. graminea has been developed

Predicting spring barley yield from variety-specific yield potential, disease resistance and straw length, and from environment-specific disease loads and weed pressure

Abstract For low-input crop production, well-characterised varieties increase the possibilities of managing diseases and weeds. This analysis aims at developing a framework for analyzing grain yield using external varietal information about disease resistance, weed competitiveness and yield potential and quantifying the impact of susceptibility grouping and straw length scores (as a measure for weed competitiveness) for predicting spring barley grain yield under variable biotic stress levels. The study comprised 52 spring barley varieties and 17 environments, i.e., combinations of location, growing system and year. Individual varieties and their interactions with environments were analysed by factorial regression of grain yield on external variety information combined with observed environmental disease loads and weed pressure. The external information was based on the official Danish VCU testing. The most parsimonious models explained about 50% of the yield variation among varieties including genotypeenvironment interactions. Disease resistance characteristics of varieties, weighted with disease loads of powdery mildew, leaf rust and net blotch, respectively, had a highly significant influence on grain yield. The extend to which increased susceptibility resulted in increased yield losses in environments with high disease loads of the respective diseases was predicted. The effect of externally determined straw length scores, weighted with weed pressure, was weaker although significant for weeds with creeping growth habit. Higher grain yield was thus predicted for taller plants under weed pressure. The results are discussed in relation to the model ramework, impact of the considered traits and use of information from conventional variety testing in organic cropping systems

Quantitative relationships in the infection cycle of seed-borne net blotch

Seed-borne net blotch is a threat to organic barley seed production in Denmark because it often exceeds the recommended 15% contamination threshold in barley seed lots. This threatens the supply of organic barley growers with organically produced healthy barley seeds. The ORGSEED project aims at quantifying the links between initial seed contamination, primary seedling infection, disease severity during the growing season, yield parameters and new contamination of the harvested grains to improve decision support for handling net blotch contaminations in organic barley- and barley seed production. The harvested grains of spring barley varieties grown at several sites in Denmark in 2002 and 2003 were used as seed lots in subsequent trials in 2003 and 2004. The seed lots covered a range of contamination levels of seed-borne net blotch for each variety. Net blotch contamination level, 1000 grain weight and germination ability of the grains were determined and net blotch development during the growing season was visually assessed. The net blotch contamination level of harvested grains was highly positively correlated with net blotch severity at growth stage 70 (beginning of grain filling, gs 70). A general linear model explained 72% of the variation of grain infection based on effects of [variety x year] and [variety x year x net blotch severity at gs 70]. Net blotch severity at gs 70 was highly positively correlated with the net blotch contamination level of the seeds and a general linear model explained 71% of the variation of net blotch severity at gs 70 based on effects of variety and seed contamination level. The results indicate that the transmission efficiency of net blotch from the epidemic on the foliage to the grains differs among varieties and that the effects of seed contamination on net blotch development later during the season may be variety-specific as well. Net blotch disease severity was highly negatively correlated with 1000 grain weight and explained, together with [site x year] effects, 58% of its variation. Our results underline the importance of varietal resistance for seed health and suggest that the level of varietal resistance be included in considerations concerning the establishment of seed contamination thresholds

Study protocol for a randomised clinical trial of a decision aid and values clarification method for parents of a fetus or neonate diagnosed with a life-threatening congenital heart defect

Introduction: Parents who receive the diagnosis of a life-threatening, complex heart defect in their fetus or neonate face a difficult choice between pursuing termination (for fetal diagnoses), palliative care or complex surgical interventions. Shared decision making (SDM) is recommended in clinical contexts where there is clinical equipoise. SDM can be facilitated by decision aids. The International Patient Decision Aids Standards collaboration recommends the inclusion of values clarification methods (VCMs), yet little evidence exists concerning the incremental impact of VCMs on patient or surrogate decision making. This protocol describes a randomised clinical trial to evaluate the effect of a decision aid (with and without a VCM) on parental mental health and decision making within a clinical encounter. Methods and analysis: Parents who have a fetus or neonate diagnosed with one of six complex congenital heart defects at a single tertiary centre will be recruited. Data collection for the prospective observational control group was conducted September 2018 to December 2020 (N=35) and data collection for two intervention groups is ongoing (began October 2020). At least 100 participants will be randomised 1:1 to two intervention groups (decision aid only vs decision aid with VCM). For the intervention groups, data will be collected at four time points: (1) at diagnosis, (2) postreceipt of decision aid, (3) postdecision and (4) 3 months postdecision. Data collection for the control group was the same, except they did not receive a survey at time 2. Linear mixed effects models will assess differences between study arms in distress (primary outcome), grief and decision quality (secondary outcomes) at 3-month post-treatment decision. Ethics and dissemination: This study was approved by the University of Utah Institutional Review Board. Study findings have and will continue to be presented at national conferences and within scientific research journals. Trial registration number: NCT04437069 (Pre-results)

Status of an Investigation of the 3-He Wave Function by Quasi-Free Scattering

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Status of an Investigation of the 3-He Wave Function by Quasi-Free Scattering

This research was sponsored by the National Science Fooundation Grant NSF PHY-931478

Status of an Investigation of the 3-He Wave Function by Quasi-Free Scattering

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

A measurement of the tau mass and the first CPT test with tau leptons

We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.

Measurement of the B0 Lifetime and Oscillation Frequency using B0->D*+l-v decays

The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.Comment: 17 pages, 4 figures, submitted to Phys. Lett.

First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons

We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/gamma* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/gamma* branching ratio to hadrons to be (0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)egamma* production, this product is found to be (4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters