1,321 research outputs found

    Embracing the future: embedding digital repositories in the University of London

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    Digital repositories can help Higher Education Institutions (HEIs) to develop coherent and coordinated approaches to capture, identify, store and retrieve intellectual assets such as datasets, course material and research papers. With the advances of technology, an increasing number of Higher Education Institutions are implementing digital repositories. The leadership of these institutions, however, has been concerned about the awareness of and commitment to repositories, and their sustainability in the future. This study informs a consortium of thirteen London institutions with an assessment of current awareness and attitudes of stakeholders regarding digital repositories in three case study institutions. The report identifies drivers for, and barriers to, the embedding of digital repositories in institutional strategy. The findings therefore should be of use to decision-makers involved in the development of digital repositories. Our approach was entirely based on consultations with specific groups of stakeholders in three institutions through interviews with specific individuals. The research in this report was prepared for the SHERPA-LEAP Consortium and conducted by RAND Europe

    Genetics of Estrogen-Related Traits; From Candidate Genes to GWAS

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    In the first part of this thesis, the association of polymorphisms in three candidate genes (estrogen receptor alpha (ESR1), retinoblastoma interacting zinc finger domain (RIZ1) and catechol-O-methyltransferase (COMT)) with estradiol levels, age at natural menopause, BMD and fracture risk in the Rotterdam Study is shown. For the ESR1 gene, fine-mapping of the PvuII and XbaI LD-block is presented, together with a haplotype analysis, showing that one additional SNP in the promoter region of the gene could distinguish a third haplotype in the previously defined PvuII–XbaI haplotype 1 and explain the associations we found before. In another study it was shown that the Pro704 insertion-deletion polymorphism in RIZ1 was not associated with BMD or fracture risk in men and women. The third study showed that the Met158Val polymorphism in the estradiol degrading enzyme COMT was associated with fracture risk, independent of BMD. In the last part genome-wide association studies (GWAS) for sex hormone binding globuline, age at menarche and age at natural menopause are presented. A GWAS on sex-hormone-binding-globuline (SHBG) levels showed highly significant associations of several SNPs in the SHBG-gene region with plasma SHBG-levels. A study on age at menarche in 17,510 women of seven studies from the CHARGE consortium identified two loci with P<5x10-8. A genome-wide association study for age at natural menopause in 2,979 European women identified three loci located on chromosome 13, 19 and 20 associated with age at natural menopause. The three loci have not been indicated to play a role in natural menopause before, and therefore the functional mechanism underlying these associations remains unknown

    A short note on the nested-sweep polarized traces method for the 2D Helmholtz equation

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    We present a variant of the solver in Zepeda-N\'u\~nez and Demanet (2014), for the 2D high-frequency Helmholtz equation in heterogeneous acoustic media. By changing the domain decomposition from a layered to a grid-like partition, this variant yields improved asymptotic online and offline runtimes and a lower memory footprint. The solver has online parallel complexity that scales \emph{sub linearly} as O(NP)\mathcal{O} \left( \frac{N}{P} \right), where NN is the number of volume unknowns, and PP is the number of processors, provided that P=O(N1/5)P = \mathcal{O}(N^{1/5}). The variant in Zepeda-N\'u\~nez and Demanet (2014) only afforded P=O(N1/8)P = \mathcal{O}(N^{1/8}). Algorithmic scalability is a prime requirement for wave simulation in regimes of interest for geophysical imaging.Comment: 5 pages, 5 figure

    Renal allograft loss due to overwhelming invasive Candida infection

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    Transposable elements promote the evolution of genome streamlining

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    Eukaryotes and prokaryotes have distinct genome architectures, withmarked differences in genome size, the ratio of coding/non-coding DNA,and the abundance of transposable elements (TEs). As TEs replicate inde-pendently of their hosts, the proliferation of TEs is thought to have drivengenome expansion in eukaryotes. However, prokaryotes also have TEs inintergenic spaces, so why do prokaryotes have small, streamlined genomes?Using anin silicomodel describing the genomes of single-celled asexualorganisms that coevolve with TEs, we show that TEs acquired from theenvironment by horizontal gene transfer can promote the evolution ofgenome streamlining. The process depends on local interactions and isunderpinned by rock–paper–scissors dynamics in which populations ofcells with streamlined genomes beat TEs, which beat non-streamlinedgenomes, which beat streamlined genomes, in continuous and repeatingcycles. Streamlining is maladaptive to individual cells, but improves lineageviability by hindering the proliferation of TEs. Streamlining does not evolvein sexually reproducing populations because recombination partially freesTEs from the deleterious effects they cause.This article is part of the theme issue‘The secret lives of microbial mobilegenetic elements’

    Augurk (onder glas) : rassenproeven eerste beoordeling 1977

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    Motives of contributing personal data for health research:(non-)participation in a Dutch biobank

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    BACKGROUND: Large-scale, centralized data repositories are playing a critical and unprecedented role in fostering innovative health research, leading to new opportunities as well as dilemmas for the medical sciences. Uncovering the reasons as to why citizens do or do not contribute to such repositories, for example, to population-based biobanks, is therefore crucial. We investigated and compared the views of existing participants and non-participants on contributing to large-scale, centralized health research data repositories with those of ex-participants regarding the decision to end their participation. This comparison could yield new insights into motives of participation and non-participation, in particular the behavioural change of withdrawal. METHODS: We conducted 36 in-depth interviews with ex-participants, participants, and non-participants of a three-generation, population-based biobank in the Netherlands. The interviews focused on the respondents' decision-making processes relating to their participation in a large-scale, centralized repository for health research data. RESULTS: The decision of participants and non-participants to contribute to the biobank was motivated by a desire to help others. Whereas participants perceived only benefits relating to their participation and were unconcerned about potential risks, non-participants and ex-participants raised concerns about the threat of large-scale, centralized public data repositories and public institutes, such as social exclusion or commercialization. Our analysis of ex-participants' perceptions suggests that intrapersonal characteristics, such as levels of trust in society, participation conceived as a social norm, and basic societal values account for differences between participants and non-participants. CONCLUSIONS: Our findings indicate the fluidity of motives centring on helping others in decisions to participate in large-scale, centralized health research data repositories. Efforts to improve participation should focus on enhancing the trustworthiness of such data repositories and developing layered strategies for communication with participants and with the public. Accordingly, personalized approaches for recruiting participants and transmitting information along with appropriate regulatory frameworks are required, which have important implications for current data management and informed consent procedures

    Infection by Wolbachia bacteria and its influence on the reproduction of the stored-product psocid, Liposcelis tricolor

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    Wolbachia are maternally inherited intracellular bacteria that infect a wide range of arthropods and nematodes and are associated with various reproductive abnormalities in their hosts. The infection by Wolbachia of the psocid, Liposcelis tricolor (Psocoptera: Liposcelididae), was investigated using long PCR amplification of the wsp gene that codes for a Wolbachia surface protein. The results showed that L. tricolor was positive for Wolbachia. Phylogenetic analysis showed that the Wolbachia found in L. tricolor was related to the B-group. Wolbachia infection in L. tricolor could be removed through antibiotic treatment. The results of crosses including ♀W+ x ♂ W+, ♀ W− x ♂W+, ♀ W+ x ♂ W−, and ♀W− x ♂ W−, suggested that the removal of Wolbachia resulted in lower egg production by L. tricolor. The mean embryonic mortality of offspring produced by L. tricolor without Wolbachia was significantly higher than that of control

    Radijs : vroege herfstteelt 1988 : rassenproef 1e beoordeling

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