326 research outputs found
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Doubled haploid ramets via embryogenesis of haploid tissue cultures
Tissue culture in the oil palm business is generally concerned with the multiplication
(clonal production) of dura, pisifera and tenera palms. These are all normal diploids
(2n=2x=36). Sumatra Bioscience has pioneered haploid tissue culture of oil palm
(n=x=18). Haploid oil palm is the first step in producing doubled haploid palms
which in turn provide parental lines for F1 hybrid production. Chromosome doubling
is known to occur during embryogenesis in other haploid cultures, e.g. barley anther
culture. Haploid tissue cultures in oil palm were therefore set up to investigate and
exploit spontaneous chromosome doubling during embryogenesis. Flow cytometry of
embryogenic tissue showed the presence of both haploid (n) and doubled haploid (2n)
cells indicating spontaneous doubling. Completely doubled haploid ramets were
regenerated suggesting that doubling occurred during the first mitoses of
embryogenesis. This is the first report of doubled haploid production in oil palm via
haploid tissue culture. The method provides a means of producing a range of doubled
haploids in oil palm from the 1,000 plus haploids available at Sumatra Bioscience, in
addition the method also produced doubled haploid (and haploid) clones.
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Methods of producing haploid and doubled haploid oil palms
The present invention relates to haploid oil palm plants and homozygous doubled haploid oil palm plants. The invention also relates to methods for producing and selecting haploid and doubled haploid plants. More particularly, but not exclusively, the method may be used for selecting haploid and doubled haploid oil palm plants. Haploid and doubled haploid plants are selected by a large-scale screening based on a combination of the phenotype with the use of molecular methods combined with flow cytometry techniques to identify haploid and doubled haploid plants. More particularly, a method for selecting haploid and doubled haploid plants is described comprising: (a) germinating seeds; (b) selecting seedlings with atypical phenotype; (c) assessing heterozygosity using markers; (d) isolating cells from the seedlings and determining the DNA content of the cells; and (e) isolating and purifying the DNA and using defined molecular markers to characterise the genotype of the plant. The haploid oil palm plants may be used for producing homozygous doubled haploid oil palms: doubled haploids may be intercrossed to produce uniform F.sub.1 hybrids of superior properties
Integrating serious games in adaptive hypermedia applications for personalised learning experiences
Game-based approaches to learning are increasingly recognized for their potential to stimulate intrinsic motivation amongst learners. While a range of examples of effective serious games exist, creating high-fidelity content with which to populate games is resource-intensive task. To reduce this resource requirement, research is increasingly exploring means to reuse and repurpose existing games. Education has proven a popular application area for Adaptive Hypermedia (AH), as adaptation can offer enriched learning experiences. Whilst content has mainly been in the form of rich text, various efforts have been made to integrate serious games into AH. However, there is little in the way of effective integrated authoring and user modeling support. This paper explores avenues for effectively integrating serious games into AH. In particular, we consider authoring and user modeling aspects in addition to integration into run-time adaptation engines, thereby enabling authors to create AH that includes an adaptive game, thus going beyond mere selection of a suitable game and towards an approach with the capability to adapt and respond to the needs of learners and educators
Touching artefacts in an ancient world on a browser-based platform
Innovations in teaching and learning process are influenced by the rapid emergence of a knowledge society and tremendous growth in demands for highly informed and educated individuals. Various kinds of computer-based learning systems have already been integrated into conventional teaching methods. However, there is a pressing need to provide a more accessible and immersive learning environment in order to increase learners' receptiveness towards the learning process. Complete involvement of learners in their learning environment will promote better absorptions of knowledge via experiential and exploratory pedagogies. In tandem with such pedagogic approaches, this paper discusses the deployment of tactile perception to complement virtual artefacts within the domain of cultural heritage. By stimulating visual and tactile perceptions, the learners' engagement and interest can be sustained. Towards enhancing accessibility to a wider demography in a more cost-effective manner, web technologies provide a platform that is widely available for mass consumption. The development capitalises on the fact that the majority of UK households have access to computers and internet
Technical evaluation of the mEducator 3.0 linked data-based environment for sharing medical educational resources
mEducator 3.0 is a content sharing approach for medical education, based on Linked Data principles. Through standardization, it enables sharing and discovery of medical information. Overall the mEducator project seeks to address the following two different approaches, mEducator 2.0, based on web 2.0 and ad-hoc Application Programmers Interfaces (APIs), and mEducator 3.0, which builds upon a collection of Semantic Web Services that federate existing sources of medical and Technology Enhanced Learning (TEL) data. The semantic mEducator 3.0 approach It has a number of different instantiations, allowing flexibility and choice. At present these comprise of a standalone social web-based instantiation (MetaMorphosis+) and instantiations integrated with Drupal, Moodle and OpenLabyrinth systems. This paper presents the evaluation results of the mEducator 3.0 Linked Data based environment for sharing medical educational resources and focuses on metadata enrichment, conformance to the requirements and technical performance (of the MetaMorphosis+ and Drupal instantiations)
A Genome-wide screen identifies frequently methylated genes in haematological and epithelial cancers
<p>Abstract</p> <p>Background</p> <p>Genetic as well as epigenetic alterations are a hallmark of both epithelial and haematological malignancies. High throughput screens are required to identify epigenetic markers that can be useful for diagnostic and prognostic purposes across malignancies.</p> <p>Results</p> <p>Here we report for the first time the use of the MIRA assay (methylated CpG island recovery assay) in combination with genome-wide CpG island arrays to identify epigenetic molecular markers in childhood acute lymphoblastic leukemia (ALL) on a genome-wide scale. We identified 30 genes demonstrating methylation frequencies of ≥25% in childhood ALL, nine genes showed significantly different methylation frequencies in B vs T-ALL. For majority of the genes expression could be restored in methylated leukemia lines after treatment with 5-azaDC. Forty-four percent of the genes represent targets of the polycomb complex. In chronic myeloid leukemia (CML) two of the genes, (<it>TFAP2A </it>and <it>EBF2)</it>, demonstrated increased methylation in blast crisis compared to chronic phase (P < 0.05). Furthermore hypermethylation of an autophagy related gene <it>ATG16L2 </it>was associated with poorer prognosis in terms of molecular response to Imatinib treatment. Lastly we demonstrated that ten of these genes were also frequently methylated in common epithelial cancers.</p> <p>Conclusion</p> <p>In summary we have identified a large number of genes showing frequent methylation in childhood ALL, methylation status of two of these genes is associated with advanced disease in CML and methylation status of another gene is associated with prognosis. In addition a subset of these genes may act as epigenetic markers across hematological malignancies as well as common epithelial cancers.</p
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Detection of Oxidation Products of 5-Methyl-2′-Deoxycytidine in Arabidopsis DNA
Epigenetic regulations play important roles in plant development and adaptation to environmental stress. Recent studies
from mammalian systems have demonstrated the involvement of ten-eleven translocation (Tet) family of dioxygenases in
the generation of a series of oxidized derivatives of 5-methylcytosine (5-mC) in mammalian DNA. In addition, these oxidized
5-mC nucleobases have important roles in epigenetic remodeling and aberrant levels of 5-hydroxymethyl-29-deoxycytidine
(5-HmdC) were found to be associated with different types of human cancers. However, there is a lack of evidence
supporting the presence of these modified bases in plant DNA. Here we reported the use of a reversed-phase HPLC coupled
with tandem mass spectrometry method and stable isotope-labeled standards for assessing the levels of the oxidized 5-mC
nucleosides along with two other oxidatively induced DNA modifications in genomic DNA of Arabidopsis. These included 5-
HmdC, 5-formyl-29-deoxycytidine (5-FodC), 5-carboxyl-29-deoxycytidine (5-CadC), 5-hydroxymethyl-29-deoxyuridine (5-
HmdU), and the (59S) diastereomer of 8,59-cyclo-29-deoxyguanosine (S-cdG). We found that, in Arabidopsis DNA, the levels
of 5-HmdC, 5-FodC, and 5-CadC are approximately 0.8 modifications per 106 nucleosides, with the frequency of 5-HmdC
(per 5-mdC) being comparable to that of 5-HmdU (per thymidine). The relatively low levels of the 5-mdC oxidation products
suggest that they arise likely from reactive oxygen species present in cells, which is in line with the lack of homologous Tetfamily
dioxygenase enzymes in Arabidopsis
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Production of haploids and doubled haploids in oil palm
Background: Oil palm is the world’s most productive oil-food crop despite yielding well below its theoretical
maximum. This maximum could be approached with the introduction of elite F1 varieties. The development of
such elite lines has thus far been prevented by difficulties in generating homozygous parental types for F1
generation.
Results: Here we present the first high-throughput screen to identify spontaneously-formed haploid (H) and
doubled haploid (DH) palms. We secured over 1,000 Hs and one DH from genetically diverse material and derived
further DH/mixoploid palms from Hs using colchicine. We demonstrated viability of pollen from H plants and
expect to generate 100% homogeneous F1 seed from intercrosses between DH/mixoploids once they develop
female inflorescences.
Conclusions: This study has generated genetically diverse H/DH palms from which parental clones can be selected
in sufficient numbers to enable the commercial-scale breeding of F1 varieties. The anticipated step increase in
productivity may help to relieve pressure to extend palm cultivation, and limit further expansion into biodiverse
rainforest
Towards a global participatory platform: Democratising open data, complexity science and collective intelligence
The FuturICT project seeks to use the power of big data, analytic models grounded in complexity science, and the collective intelligence they yield for societal benefit. Accordingly, this paper argues that these new tools should not remain the preserve of restricted government, scientific or corporate élites, but be opened up for societal engagement and critique. To democratise such assets as a public good, requires a sustainable ecosystem enabling different kinds of stakeholder in society, including but not limited to, citizens and advocacy groups, school and university students, policy analysts, scientists, software developers, journalists and politicians. Our working name for envisioning a sociotechnical infrastructure capable of engaging such a wide constituency is the Global Participatory Platform (GPP). We consider what it means to develop a GPP at the different levels of data, models and deliberation, motivating a framework for different stakeholders to find their ecological niches at different levels within the system, serving the functions of (i) sensing the environment in order to pool data, (ii) mining the resulting data for patterns in order to model the past/present/future, and (iii) sharing and contesting possible interpretations of what those models might mean, and in a policy context, possible decisions. A research objective is also to apply the concepts and tools of complexity science and social science to the project's own work. We therefore conceive the global participatory platform as a resilient, epistemic ecosystem, whose design will make it capable of self-organization and adaptation to a dynamic environment, and whose structure and contributions are themselves networks of stakeholders, challenges, issues, ideas and arguments whose structure and dynamics can be modelled and analysed. Graphical abstrac
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