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Kesara Anamthawat-Jónsson Sigrídur K. Bödvarsdóttir Birkir Th. Bragason Jón Gudmundsson P.K. Martin R.M.D. Koebner 《Euphytica》1997,93(3):293-300
A total of 240 F1 hybrids was made beween wheat (Triticum aestivum L. em. Thell. (2n = 6x = 42) and T. carthlicum Nevski (2n = 4x = 28)) and
perennial lymegrass (North European Leymus arenarius (L.) Hochst. (2n = 8x = 56) and North American L. mollis (Trin.) Pilger
(2n = 4x = 28)). The wide crosses yielded embryos in 20% of caryopses and 96% of the embryos developed into normal hybrid
plants. The hybrids were vegetatively vigorous, with evidence of the Leymus rhizomatous habit. Those deriving from L. arenarius
survived overwintering in Iceland, but the hybrids L. mollis did not, whereas in a milder environment, both showed perenniality.
Cytogenetic analysis of root tip cells before the plants were treated with colchicine showed that 21 out of 28 hybrids investigated
had chromosome mosaics, with a population of both amphihaploid and amphidiploid cells. This spontaneous doubling of somatic
chromosomes occurred in all cross combinations, with the highest average frequency of diploid cells (28%) in T. carthlicum
× L. arenarius crosses. A few selfed seeds have been obtained from a T. aestivum × L. arenarius hybrid. All the hybrids were
treated twice with colchicine, but the treatment appeared to have little or no effect on the frequency of chromosome doubling
in the hybrids deriving from T. aestivum. The frequency of diploid cells, however, increased significantly (e.g. to 80%) in
the hybrids deriving from the T. carthlicum parent. Genomic in situ hybridization confirmed the hybridity of the plants and
showed that the hybrids were amphiploids containing genomes of both wheat and lymegrass. In situ hybridization using ribosomal
DNA probe differentiated chromosomes of L. mollis, L. arenarius from those of wheat. The hybrids are being backcrossed with
lymegrass pollen, aiming to domesticate the wild, perennial species.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Sigríeur Bj?rnsdóttir Elfa Agustsdóttir Anne-Lie Blomstr?m Inga-Lena ?rde ?str?m Louise Treiberg Berndtsson Vilhjálmur Svansson Jonas Johansson Wensman 《Acta veterinaria Scandinavica》2013,55(1):77
Background
In a stable of eight horses in Northern Iceland, six horses presented with clinical signs, such as ataxia and reduced appetite, leading to euthanasia of one severely affected horse. Serological investigations revealed no evidence of active equine herpes virus type 1 infection, a common source of central nervous system disease in horses, nor equine arteritis virus and West Nile virus. Another neurotropic virus, Borna disease virus, was therefore included in the differential diagnosis list.Findings
Serological investigations revealed antibodies against Borna disease virus in four of five horses with neurological signs in the affected stable. One horse without clinical signs was seronegative. Four clinically healthy horses in the stable that arrived and were sampled one year after the outbreak were found seronegative, whereas one of four investigated healthy horses in an unaffected stable was seropositive.Conclusions
This report contains the first evidence of antibodies to Borna disease virus in Iceland. Whether Borna disease virus was the cause of the neurological signs could however not be confirmed by pathology or molecular detection of the virus. As Iceland has very restricted legislation regarding animal imports, the questions of how this virus has entered the country and to what extent markers of Bornavirus infection can be found in humans and animals in Iceland remain to be answered. 相似文献3.
Kåre Nolde Nielsen Michaela Maria Aschan Sveinn Agnarsson Marta Ballesteros Alan Baudron Maria de Fátima Borges Aida Campos Rosa Chapela Anna Kristín Daníelsdóttir Karim Erzini Ólavur Gregersen Petter Holm Alessandro Lucchetti Sveinn Margeirsson Hugo Vilela Mendes Petter Olsen Mafalda Rangel Antonello Sala José Luis Santiago Sigríður Sigurðardóttir Cristina Silva Daryl Sykes Jónas Rúnar Viðarsson Massimo Virgili Laura Wise Paul George Fernandes 《Fish and Fisheries》2018,19(2):363-376
We present a framework for results‐based management (RBM) of commercial fisheries. The core idea of RBM is to reduce micromanagement by delegating management responsibility to resource users. The RBM framework represents an industrial organization approach to co‐management and comprises three defining processes, conducted by three independent “agents”: (i) an “authority” defines specific and measurable and achievable objectives (outcome targets, OTs) for the utilization of fisheries resources, (ii) resource user organizations (termed “operators”) take responsibility for achieving these OTs and provide documentation that (iii) allows independent “auditors” to evaluate the achievement of OTs. Using incentive mechanisms, notably deregulation, RBM grants operators the flexibility to develop and implement innovative and cost‐effective ways to achieve OTs. The feasibility of implementing RBM in five European fisheries was investigated in cooperation with relevant stakeholders through artificial planning processes and computer simulations. The operators involved were enthusiastic, and new management plans were drafted based on the framework. These included socioeconomic OTs in addition to traditional stock objectives, encompassing an ecosystem approach. Several issues are in need of further research to consolidate the approach and prepare the ground for practical implementation, including: the specification of the legal and regulatory framework required to underpin RBM, details of transitional arrangements when shifting towards RBM (including cost‐sharing) and the development of necessary organizational capacity for operators. Initially, we therefore envisage the framework being applied to high‐value single‐species fisheries, with a limited number of participants, which are adequately represented by a competent organization. 相似文献
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Priyanka Sahariah Vivek S. Gaware Ramona Lieder Sigríeur Jónsdóttir Martha á. Hjálmarsdóttir Olafur E. Sigurjonsson Már Másson 《Marine drugs》2014,12(8):4635-4658
A series of water-soluble cationic chitosan derivatives were prepared by chemoselective functionalization at the amino group of five different parent chitosans having varying degrees of acetylation and molecular weight. The quaternary moieties were introduced at different alkyl spacer lengths from the polymer backbone (C-0, C-2 and C-6) with the aid of 3,6-di-O-tert-butyldimethylsilyl protection of the chitosan backbone, thus allowing full (100%) substitution of the free amino groups. All of the derivatives were characterized using 1H-NMR, 1H-1H COSY and FT-IR spectroscopy, while molecular weight was determined by GPC. Antibacterial activity was investigated against Gram positive S. aureus and Gram negative E. coli. The relationship between structure and activity/toxicity was defined, considering the effect of the cationic group’s structure and its distance from the polymer backbone, as well as the degree of acetylation within a molecular weight range of 7–23 kDa for the final compounds. The N,N,N-trimethyl chitosan with 100% quaternization showed the highest antibacterial activity with moderate cytotoxicity, while increasing the spacer length reduced the activity. Trimethylammoniumyl quaternary ammonium moieties contributed more to activity than 1-pyridiniumyl moieties. In general, no trend in the antibacterial activity of the compounds with increasing molecular weight or degree of acetylation up to 34% was observed. 相似文献
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