1,315 research outputs found

    Advanced and conventional methods for vegetative propagation of selected lines of oak and cherry.

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    End of Project ReportTeagasc acknowledges with gratitude the support of the European Commission, ECLAIR, and the Human Capital and Mobility Programme in the financing of this research project.Oak and wild cherry (Prunus avium) are important broadleaved species. We have identified superior trees and conserved them by grafting. Methods for the large scale propagation of selected trees was evaluated using the technology of micropropagation. For oak we could establish shoot cultures from mature oaks but their propagation rate was too low and difficult for practical application. With wild cherry micropropagation is a feasible option for large scale production of selected material. Genetic fingerprinting technology was developed and applied to oaks. We showed that all material propagated vegetatively from oak was genetically similar to the original donor tree. Furthermore we used genetic fingerprinting to analyse a unique stand of elite oaks in Co. Westmeath and determined that the selected trees were not closely related to each other. The analysis of genetic fingerprints of 16 elite oaks also showed that five of them had an unusual pattern of DNA and one tree was identified as a rare triploid tree.European Unio

    High levels of gene flow and genetic diversity in Irish populations of Salix caprea L. inferred from chloroplast and nuclear SSR markers

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    peer-reviewedBackground Salix caprea is a cold-tolerant pioneer species that is ecologically important in Europe and western and central Asia. However, little data is available on its population genetic structure and molecular ecology. We describe the levels of geographic population genetic structure in natural Irish populations of S. caprea and determine the extent of gene flow and sexual reproduction using both chloroplast and nuclear simple sequence repeats (SSRs). Results A total of 183 individuals from 21 semi-natural woodlands were collected and genotyped. Gene diversity across populations was high for the chloroplast SSRs (H T  = 0.21-0.58) and 79 different haplotypes were discovered, among them 48% were unique to a single individual. Genetic differentiation of populations was found to be between moderate and high (mean G ST  = 0.38). For the nuclear SSRs, G ST was low at 0.07 and observed heterozygosity across populations was high (H O  = 0.32-0.51); only 9.8% of the genotypes discovered were present in two or more individuals. For both types of markers, AMOVA showed that most of the variation was within populations. Minor geographic pattern was confirmed by a Bayesian clustering analysis. Gene flow via pollen was found to be approximately 7 times more important than via seeds. Conclusions The data are consistent with outbreeding and indicate that there are no significant barriers for gene flow within Ireland over large geographic distances. Both pollen-mediated and seed-mediated gene flow were found to be high, with some of the populations being more than 200 km apart from each other. These findings could simply be due to human intervention through seed trade or accidental transportation of both seeds and pollen. These results are of value to breeders wishing to exploit natural genetic variation and foresters having to choose planting material.Teagasc Walsh Fellowship Programm

    Collection and rejuvenation of rare/scarce plants for the nursey stock industry.

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    End of Project ReportThe main objectives of this project were: ‱ Location of scarce/rare or new plants of high garden merit with tolerance to disease and pests ‱ Rejuvenation. ‱ Conservation of rejuvenated plants in the original gardens from which they were collected, at the Kinsealy Research Centre and in other selected locations. ‱ Evaluation of the collection for a variety of uses – foliage, patio etc. over a range of different conditions and locations. ‱ Plant identification. ‱ Commercialisation of these plants by the trade to extend their range of plants.European Union Structural Funds (EASSF

    Ash dieback on the island of Ireland

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    Book sectionThis publication is based on the work of Action FP1103 FRAXBACK, supported by COST (European Cooperation in Science and Technology)On the island of Ireland it is estimated that there are over half a million kilometres of hedgerows (400,000+ km in the Republic of Ireland (Rep. Ireland) and 113,000+ in Northern Ireland (Northern Ireland). Ash (Fraxinus excelsior) is the second most important component, after hawthorn (Crataegus monogyna), in large proportions of this hedgerow network. In the Rep. Ireland over 20,000 ha of ash have been planted since 1990, primarily for sawlogs and to provide material for the manufacture of hurleys, which are used in an important national sport called hurling, and for camogie sticks used to play camogie. Ash dieback, caused by Hymenoscyphus fraxineus, was first identified on the island in October 2012 and since then has been detected at 306 sites (195 in Rep. Ireland and 111 in Northern Ireland). In the vast majority of cases the outbreaks have been on young, imported trees planted within the previous 5 – 6 years and it was evident that the pathogen had been introduced on trees for planting. On a small number of occasions there was evidence of the pathogen cycling within a plantation or moving from the plantation to infect neighbouring hedgerow trees. One possible mechanism by which the pathogen can build up sufficient inoculum is by the formation of apothecia on infected woody tissue high up on the plants. Rep. Ireland and Northern Ireland have strict policies of eradication and containment, as set out in the All-Ireland Chalara Control Strategy. To date over 2.1 million trees have been destroyed as part of an eradication strategy. It is considered that this prompt and far-reaching action has had a significant impact, significantly mitigating and preventing the rapid establishment of the pathogen and limiting its spread. The interventions since the disease was first confirmed have helped to protect the considerable investment in ash plantations of the last 20 years. The pathogen has not, however, been eradicated from the island of Ireland and it remains to be seen how widespread, and how quickly ash dieback will become established on the island of Ireland. The latest figures from the Republic of Ireland are that 733 hectares of ash plantation has been reconstituted with another species as a result of Chalara and this has cost our state €2.6 million so far; in addition, Chalara has been found and confirmed in all 26 counties of the Republic of Ireland to a greater or lesser extent. As a result the current policies and procedures regarding Chalara are under review.This publication is based on the work of Action FP1103 FRAXBACK, supported by COST (European Cooperation in Science and Technology

    Detection and isolation of exotic Newcastle disease virus from field-collected flies.

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    Flies were collected by sweep net from the vicinity of two small groups of "backyard" poultry (10-20 chickens per group) that had been identified as infected with exotic Newcastle disease virus (family Paramyxoviridae, genus avulavirus, ENDV) in Los Angeles County, CA, during the 2002-2003 END outbreak. Collected flies were subdivided into pools and homogenized in brain-heart infusion broth with antibiotics. The separated supernatant was tested for the presence of ENDV by inoculation into embryonated chicken eggs. Exotic Newcastle disease virus was isolated from pools of Phaenicia cuprina (Wiedemann), Fannia canicularis (L.), and Musca domestica L., and it was identified by hemagglutination inhibition with Newcastle disease virus antiserum. Viral concentration in positive pools was low (<1 egg infectious dose50 per fly). Isolated virus demonstrated identical monoclonal antibody binding profiles as well as 99% sequence homology in the 635-bp fusion gene sequence compared with ENDV recovered from infected commercial egg layer poultry during the 2002 outbreak

    Vegetative propagation of dieback-tolerant Fraxinus excelsior on

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    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

    Alley coppice—a new system with ancient roots

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    International audience& Context Current production from natural forests will not satisfy future world demand for timber and fuel wood, and new land management options are required. & Aims We explore an innovative production system that combines the production of short rotation coppice in wide alleys with the production of high-value trees on narrow strips of land; it is an alternative form of alley cropping which we propose to call 'alley coppice'. The aim is to describe this alley coppice system and to illustrate its potential for produc-ing two diverse products, namely high-value timber and ener-gy wood on the same land unit. & Methods Based on a comprehensive literature review, we compare the advantages and disadvantages of the alley cop-pice system and contrast the features with well-known existing or past systems of biomass and wood production. & Results We describe and discuss the basic aspects of alley coppice, its design and dynamics, the processes of competi-tion and facilitation, issues of ecology, and areas that are open for future research. & Conclusion Based on existing knowledge, a solid founda-tion for the implementation of alley coppice on suitable land is presented, and the high potential of this system could be shown

    The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI

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    The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to deliver data at the Hat Creek Radio Observatory in Northern California. Scientists and engineers are actively exploiting all of the flexibility designed into this innovative instrument for simultaneously conducting surveys of the astrophysical sky and conducting searches for distant technological civilizations. This paper summarizes the design elements of the ATA, the cost savings made possible by the use of COTS components, and the cost/performance trades that eventually enabled this first snapshot radio camera. The fundamental scientific program of this new telescope is varied and exciting; some of the first astronomical results will be discussed.Comment: Special Issue of Proceedings of the IEEE: "Advances in Radio Telescopes", Baars,J. Thompson,R., D'Addario, L., eds, 2009, in pres

    The Allen Telescope Array Twenty-centimeter Survey - A 690-Square-Degree, 12-Epoch Radio Dataset - I: Catalog and Long-Duration Transient Statistics

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    We present the Allen Telescope Array Twenty-centimeter Survey (ATATS), a multi-epoch (12 visits), 690 square degree radio image and catalog at 1.4GHz. The survey is designed to detect rare, very bright transients as well as to verify the capabilities of the ATA to form large mosaics. The combined image using data from all 12 ATATS epochs has RMS noise sigma = 3.94mJy / beam and dynamic range 180, with a circular beam of 150 arcsec FWHM. It contains 4408 sources to a limiting sensitivity of S = 20 mJy / beam. We compare the catalog generated from this 12-epoch combined image to the NRAO VLA Sky Survey (NVSS), a legacy survey at the same frequency, and find that we can measure source positions to better than ~20 arcsec. For sources above the ATATS completeness limit, the median flux density is 97% of the median value for matched NVSS sources, indicative of an accurate overall flux calibration. We examine the effects of source confusion due to the effects of differing resolution between ATATS and NVSS on our ability to compare flux densities. We detect no transients at flux densities greater than 40 mJy in comparison with NVSS, and place a 2-sigma upper limit on the transient rate for such sources of 0.004 per square degree. These results suggest that the > 1 Jy transients reported by Matsumura et al. (2009) may not be true transients, but rather variable sources at their flux density threshold.Comment: 41 pages, 19 figures, ApJ accepted; corrected minor typo in Table

    Decentralised Clinical Trials in Multiple Sclerosis Research

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    Randomised controlled trials (RCTs) play an important role in multiple sclerosis (MS) research, ensuring that new interventions are safe and efficacious before their introduction into clinical practice. Trials have been evolving to improve the robustness of their designs and the efficiency of their conduct. Advances in digital and mobile technologies in recent years have facilitated this process and the first RCTs with decentralised elements became possible. Decentralised clinical trials (DCTs) are conducted remotely, enabling participation of a more heterogeneous population who can participate in research activities from different locations and at their convenience. DCTs also rely on digital and mobile technologies which allows for more flexible and frequent assessments. While hospitals quickly adapted to e-health and telehealth assessments during the COVID-19 pandemic, the conduct of conventional RCTs was profoundly disrupted. In this paper, we review the existing evidence and gaps in knowledge in the design and conduct of DCTs in MS
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