Population Genetics of Perennial Ryegrass (\u3cem\u3eLolium Perenne\u3c/em\u3e L.): Differentiation of Pasture and Turf Cultivars

Cultivar differentiation using molecular markers to assess genetic variation may be of value in obtaining or protecting plant breeders rights. A knowledge of genetic variation and how it is structured within perennial ryegrass (Lolium perenne L.) populations will also help us understand the consequences to fitness and adaptation when implementing molecular breeding strategies. In a study of the population genetic structure of a number of perennial ryegrass varieties we examined the cultivar differentiation potential of marker technology

Application of Molecular Technologies in Forage Plant Breeding

Key points A range of molecular breeding technologies have been developed for forage plant species including both transgenic and non-transgenic methodologies. The application of these technologies has the potential to greatly increase the range of genetic variation that is available for incorporation into breeding programs and subsequent delivery to producers in the form of improved germplasm. Further developments in detailing the phenotypic effect of genes and alleles both through research in target species and through inference from results from model species will further refine the delivery of new forage cultivars

Gene-Associated Single Nucleotide Polymorphism Discovery in White Clover (\u3cem\u3eT. Repens\u3c/em\u3e L.)

Single nucleotide polymorphism (SNP) discovery permits the discovery of molecular marker variation associated with functionally-defined genes. SNP markers have been developed for the temperate pasture legume crop white clover (Trifolium repens) using public and proprietary genic sequences correlated with key agronomic traits of interest

The influence of the addition of isoprene on the volatility of particles formed from the photo-oxidation of anthropogenic–biogenic mixtures

In this study, we investigate the influence of isoprene on the volatility of secondary organic aerosol (SOA) formed during the photo-oxidation of mixtures of anthropogenic and biogenic precursors. The SOA particle volatility was quantified using two independent experimental techniques (using a thermal denuder and the Filter Inlet for Gas and Aerosols iodide high-resolution time-of-flight Chemical Ionisation Mass Spectrometer – FIGAERO-CIMS) in mixtures of α-pinene/isoprene, o-cresol/isoprene, and α-pinene/o-cresol/isoprene. Single-precursor experiments at various initial concentrations and results from previous α-pinene/o-cresol experiments were used as a reference. The oxidation of isoprene did not result in the formation of detectable SOA particle mass in single-precursor experiments. However, isoprene-derived products were identified in the mixed systems, likely due to the increase in the total absorptive mass. The addition of isoprene resulted in mixture-dependent influence on the SOA particle volatility. Isoprene made no major change to the volatility of α-pinene SOA particles, though changes in the SOA particle composition were observed and the volatility was reasonably predicted based on the additivity. Isoprene addition increased o-cresol SOA particle volatility by ∼5/15 % of the total mass/signal, respectively, indicating a potential to increase the overall volatility that cannot be predicted based on the additivity. The addition of isoprene to the α-pinene/o-cresol system (i.e. α-pinene/o-cresol/isoprene) resulted in slightly fewer volatile particles than those measured in the α-pinene/o-cresol systems. The measured volatility in the α-pinene/o-cresol/isoprene system had an ∼6 % higher low volatile organic compound (LVOC) mass/signal compared to that predicted assuming additivity with a correspondingly lower semi-volatile organic compound (SVOC) fraction. This suggests that any effects that could increase the SOA volatility from the addition of isoprene are likely outweighed by the formation of lower-volatility compounds in more complex anthropogenic–biogenic precursor mixtures. Detailed chemical composition measurements support the measured volatility distribution changes and showed an abundance of unique-to-the-mixture products appearing in all the mixed systems accounting for around 30 %–40 % of the total particle-phase signal. Our results demonstrate that the SOA particle volatility and its prediction can be affected by the interactions of the oxidized products in mixed-precursor systems, and further mechanistic understanding is required to improve their representation in chemical transport models.</p

Molecular Breeding of Transgenic Virus-Immune White Clover (\u3cem\u3eTrifolium Repens\u3c/em\u3e) Cultivars

White clover (T. repens L.) is a major component of improved pastures throughout the temperate world. It is, however, highly susceptible to virus infection. Alfalfa mosaic virus (AMV), clover yellow vein virus (CYVV) and white clover mosaic virus (WCMV) all contribute to a significant reduction in dry matter yield and persistence of white clover. Sources of natural resistance to AMV in white clover or sexually compatible species are not available. Pathogen-derived resistance strategies, such as the expression of viral coat protein in transgenic plants, thus provides opportunities for the development of virus immune transgenic white clover

Genetic Variation in the Perennial Ryegrass Fungal Endophyte \u3cem\u3eNeotyphodium Lolii\u3c/em\u3e

The common fungal endophytes (Neotyphodium species) of temperate pasture grasses are associated with improved tolerance to water and nutrient stress and resistance to insect pests, but are also the causal agents of animal toxicoses. Considerable variation exists among grass-endophyte associations for these beneficial and detrimental agronomic traits. The extent to which this variation may be attributed to the endophyte genotype, the host genotype or environmental interactions is currently unknown. The development of molecular genetic markers for endophytes based on simple sequence repeat (SSR) loci and the demonstration of the specific detection of endophytes in planta with these markers (van Zijll de Jong et al., 2005) allows efficient assessment of endophyte diversity in grass populations

Sustained VWF‐ADAMTS‐13 axis imbalance and endotheliopathy in long COVID syndrome is related to immune dysfunction

Background Prolonged recovery is common after acute SARS-CoV-2 infection; however, the pathophysiological mechanisms underpinning Long COVID syndrome remain unknown. VWF/ADAMTS-13 imbalance, dysregulated angiogenesis, and immunothrombosis are hallmarks of acute COVID-19. We hypothesized that VWF/ADAMTS-13 imbalance persists in convalescence together with endothelial cell (EC) activation and angiogenic disturbance. Additionally, we postulate that ongoing immune cell dysfunction may be linked to sustained EC and coagulation activation. Patients and methods Fifty patients were reviewed at a minimum of 6 weeks following acute COVID-19. ADAMTS-13, Weibel Palade Body (WPB) proteins, and angiogenesis-related proteins were assessed and clinical evaluation and immunophenotyping performed. Comparisons were made with healthy controls (n = 20) and acute COVID-19 patients (n = 36). Results ADAMTS-13 levels were reduced (p = 0.009) and the VWF-ADAMTS-13 ratio was increased in convalescence (p = 0.0004). Levels of platelet factor 4 (PF4), a putative protector of VWF, were also elevated (p = 0.0001). A non-significant increase in WPB proteins Angiopoietin-2 (Ang-2) and Osteoprotegerin (OPG) was observed in convalescent patients and WPB markers correlated with EC parameters. Enhanced expression of 21 angiogenesis-related proteins was observed in convalescent COVID-19. Finally, immunophenotyping revealed significantly elevated intermediate monocytes and activated CD4+ and CD8+ T cells in convalescence, which correlated with thrombin generation and endotheliopathy markers, respectively. Conclusion Our data provide insights into sustained EC activation, dysregulated angiogenesis, and VWF/ADAMTS-13 axis imbalance in convalescent COVID-19. In keeping with the pivotal role of immunothrombosis in acute COVID-19, our findings support the hypothesis that abnormal T cell and monocyte populations may be important in the context of persistent EC activation and hemostatic dysfunction during convalescence

Design-Based Research in CALL

The purpose of this volume is to expand and refine our understanding of the use of design-based research (DBR) in CALL by contributing to the growing body of literature in this area. We have tried our best to strike a balance between theoretical considerations and concrete examples of DBR. The first section of this volume focuses on theoretical perspectives and ideas that can inform the use of DBR in CALL. The second section contains studies that illustrate DBR through concrete instances of its operationalization. We hope this volume will be a useful source of information and inspiration for those considering to further explore DBR in CALL. For updates on DBR in CALL, please visit the companion site to this volume: https://sites.google.com/site/designbasedresearch/https://lib.dr.iastate.edu/language_books/1006/thumbnail.jp

A method for extracting calibrated volatility information from the FIGAERO-HR-ToF-CIMS and its experimental application

The Filter Inlet for Gases and AEROsols (FIGAERO) is an inlet specifically designed to be coupled with the Aerodyne High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS). The FIGAERO-HR-ToF-CIMS provides simultaneous molecular information relating to both the gas- and particle-phase samples and has been used to extract vapour pressures (VPs) of the compounds desorbing from the filter whilst giving quantitative concentrations in the particle phase. However, such extraction of vapour pressures of the measured particle-phase components requires use of appropriate, well-defined, reference compounds. Vapour pressures for the homologous series of polyethylene glycols (PEG) ((H-(O-CH2CH2)n-OH) for n = 3 to n = 8), covering a range of vapour pressures (VP) (10-1 to 10-7 Pa) that are atmospherically relevant, have been shown to be reproduced well by a range of different techniques, including Knudsen Effusion Mass Spectrometry (KEMS). This is the first homologous series of compounds for which a number of vapour pressure measurement techniques have been found to be in agreement, indicating the utility as a calibration standard, providing an ideal set of benchmark compounds for accurate characterization of the FIGAERO for extracting vapour pressure of measured compounds in chambers and the real atmosphere. To demonstrate this, single-component and mixture vapour pressure measurements are made using two FIGAERO-HR-ToF-CIMS instruments based on a new calibration determined from the PEG series. VP values extracted from both instruments agree well with those measured by KEMS and reported values from literature, validating this approach for extracting VP data from the FIGAERO. This method is then applied to chamber measurements, and the vapour pressures of known products are estimated