328 research outputs found
Wheat-barley hybridization – the last forty years
Abstract Several useful alien gene transfers have
been reported from related species into wheat (Triticum
aestivum), but very few publications have dealt
with the development of wheat/barley (Hordeum
vulgare) introgression lines. An overview is given
here of wheat 9 barley hybridization over the last
forty years, including the development of
wheat 9 barley hybrids, and of addition and translocation
lines with various barley cultivars. A short
summary is also given of the wheat 9 barley hybrids
produced with other Hordeum species. The meiotic
pairing behaviour of wheat 9 barley hybrids is presented,
with special regard to the detection of wheat–
barley homoeologous pairing using the molecular
cytogenetic technique GISH. The effect of in vitro
multiplication on the genome composition of intergeneric
hybrids is discussed, and the production and
characterization of the latest wheat/barley translocation
lines are presented. An overview of the agronomical
traits (b-glucan content, earliness, salt tolerance,
sprouting resistance, etc.) of the newly developed
introgression lines is given. The exploitation and
possible use of wheat/barley introgression lines for
the most up-to-date molecular genetic studies
(transcriptome analysis, sequencing of flow-sorted
chromosomes) are also discussed
Regression models for analyzing radiological visual grading studies – an empirical comparison
Multiyear inter-laboratory exercises for the analysis of illicit drugs and metabolites in wastewater: development of a quality control system
Multi-year interlaboratory exercises for the analysis of illicit drugs and metabolites in wastewater:development of a quality control system
This study presents the development of a worldwide inter-laboratory testing scheme for the analysis of seven illicit drug residues in different matrices (standard solutions, tap- and wastewater). By repeating this exercise for six years with participation of 37 laboratories from 25 countries, the testing scheme was substantially improved based on experiences gained across the years (e.g. matrix type, sample conditions, spiking levels). From the exercises (pre-)analytical issues (e.g. pH adjustment, filtration), were revealed for some analytes which resulted in formulation of best-practice protocols, both for inter-laboratory setup and analytical procedures. The results illustrate the effectiveness of the inter-laboratory testing scheme in assessing laboratory performance in the framework of illicit drug analysis in wastewater. The exercise proved that measurements of laboratories were of high quality (>80% satisfactory results for 6 out of 7 analytes) and that analytical follow-up is important to assist laboratories in improving robustness of wastewater-based epidemiology results
The potential risks and impact of the start of the 2015–2016 influenza season in the WHO European Region: a rapid risk assessment
Background: Countries in the World Health Organization (WHO) European Region are reporting more severe influenza activity in the 2015–2016 season compared to previous seasons. Objectives: To conduct a rapid risk assessment to provide interim information on the severity of the current influenza season. Methods: Using the WHO manual for rapid risk assessment of acute public health events and surveillance data available from Flu News Europe, an assessment of the current influenza season from 28 September 2015 (week 40/2015) up to 31 January 2016 (week 04/2016) was made compared with the four previous seasons. Results: The current influenza season started around week 51/2015 with higher influenza activity reported in Eastern Europe compared to Western Europe. There is a strong predominance of influenza A(H1N1)pdm09 compared to previous seasons, but the virus is antigenically similar to the strain included in the seasonal influenza vaccine. Compared to the 2014/2015 season, there was a rapid increase in the number of severe cases in Eastern European countries with the majority of such cases occurring among adults aged < 65 years. Conclusions: The current influenza season is characterized by an early start in Eastern European countries, with indications of a more severe season. Currently circulating influenza A(H1N1)pdm09 viruses are antigenically similar to those included in the seasonal influenza vaccine, and the vaccine is expected to be effective. Authorities should provide information to the public and health providers about the current influenza season, recommendations for the treatment of severe disease and effective public health measures to prevent influenza transmission
A Continental-Wide Perspective: The Genepool of Nuclear Encoded Ribosomal DNA and Single-Copy Gene Sequences in North American Boechera (Brassicaceae)
74 of the currently accepted 111 taxa of the North American genus Boechera (Brassicaceae) were subject to pyhlogenetic reconstruction and network analysis. The dataset comprised 911 accessions for which ITS sequences were analyzed. Phylogenetic analyses yielded largely unresolved trees. Together with the network analysis confirming this result this can be interpreted as an indication for multiple, independent, and rapid diversification events. Network analyses were superimposed with datasets describing i) geographical distribution, ii) taxonomy, iii) reproductive mode, and iv) distribution history based on phylogeographic evidence. Our results provide first direct evidence for enormous reticulate evolution in the entire genus and give further insights into the evolutionary history of this complex genus on a continental scale. In addition two novel single-copy gene markers, orthologues of the Arabidopsis thaliana genes At2g25920 and At3g18900, were analyzed for subsets of taxa and confirmed the findings obtained through the ITS data
Reproductive Ecology and Severe Pollen Limitation in the Polychromic Tundra Plant, Parrya nudicaulis (Brassicaceae)
Pollen limitation is predicted to be particularly severe in tundra habitats. Numerous reproductive patterns associated with alpine and arctic species, particularly mechanisms associated with reproductive assurance, are suggested to be driven by high levels of pollen limitation. We studied the reproductive ecology of Parrya nudicaulis, a species with relatively large sexual reproductive investment and a wide range of floral pigmentation, in tundra habitats in interior montane Alaska to estimate the degree of pollen limitation. The plants are self-compatible and strongly protandrous, setting almost no seed in the absence of pollinators. Supplemental hand pollinations within pollinator exclusion cages indicated no cage effect on seed production. Floral visitation rates were low in both years of study and particularly infrequent in 2010. A diversity of insects visited P. nudicaulis, though syrphid and muscid flies composed the majority of all visits. Pollen-ovule ratios and levels of heterozygosity are consistent with a mixed mating system. Pollen limitation was severe; hand pollinations increased seed production per plant five-fold. Seed-to-ovule ratios remained low following hand pollinations, indicating resource limitation is likely to also be responsible for curtailing seed set. We suggest that pollen limitation in P. nudicaulis may be the result of selection favoring an overproduction of ovules as a bet-hedging strategy in this environmental context of highly variable pollen receipt
Studies on central baffin vegetation I. Bray Island
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43889/1/11258_2004_Article_BF00299587.pd
Molecular evolution in court: analysis of a large hepatitis C virus outbreak from an evolving source
Spatio-temporal assessment of illicit drug use at large scale: evidence from 7 years of international wastewater monitoring
- …
