19 research outputs found

    Isolation of a natural DNA virus of <i>Drosophila melanogaster</i>, and characterisation of host resistance and immune responses

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    <div><p><i>Drosophila melanogaster</i> has played a key role in our understanding of invertebrate immunity. However, both functional and evolutionary studies of host-virus interaction in <i>Drosophila</i> have been limited by a dearth of native virus isolates. In particular, despite a long history of virus research, DNA viruses of <i>D</i>. <i>melanogaster</i> have only recently been described, and none have been available for experimental study. Here we report the isolation and comprehensive characterisation of Kallithea virus, a large double-stranded DNA virus, and the first DNA virus to have been reported from wild populations of <i>D</i>. <i>melanogaster</i>. We find that Kallithea virus infection is costly for adult flies, reaching high titres in both sexes and disproportionately reducing survival in males, and movement and late fecundity in females. Using the <i>Drosophila</i> Genetic Reference Panel, we quantify host genetic variance for virus-induced mortality and viral titre and identify candidate host genes that may underlie this variation, including <i>Cdc42-interacting protein 4</i>. Using full transcriptome sequencing of infected males and females, we examine the transcriptional response of flies to Kallithea virus infection and describe differential regulation of virus-responsive genes. This work establishes Kallithea virus as a new tractable model to study the natural interaction between <i>D</i>. <i>melanogaster</i> and DNA viruses, and we hope it will serve as a basis for future studies of immune responses to DNA viruses in insects.</p></div

    Population-Based Design of Mandibular Plates Based on Bone Quality and Morphology

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    In this paper we present a new population-based implant design methodology, which advances the state-of-the-art approaches by combining shape and bone quality information into the design strategy. The method enhances the mechanical stability of the fixation and reduces the intra-operative in-plane bending which might impede the functionality of the locking mechanism. The method is presented for the case of mandibular locking fixation plates, where the mandibular angle and the bone quality at screw locations are taken into account. Using computational anatomy techniques, the method automatically derives, from a set of computed tomography images, the mandibular angle and the bone thickness and intensity values at the path of every screw. An optimisation strategy is then used to optimise the two parameters of plate angle and screw position. Results for the new design are presented along with a comparison with a commercially available mandibular locking fixation plate. A statistically highly significant improvement was observed. Our experiments allowed us to conclude that an angle of 126° and a screw separation of 8mm is a more suitable design than the standard 120° and 9mm

    Liquid index matching for 2D and 3D terahertz imaging

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    International audienceTwo-dimensional (2D) terahertz imaging and 3D visualization suffer from severe artifacts since an important part of the terahertz beam is reflected, diffracted, and refracted at each interface. These phenomena are due to refractive index mismatch and reflection in the case of non-orthogonal incidence. This paper proposes an experimental procedure that reduces these deleterious optical refraction effects for a cylinder and a prism made with polyethyl-ene material. We inserted these samples in a low absorption liquid medium to match the sample index. We then replaced the surrounding air with a liquid with an optimized refractive index, with respect to the samples being studied. Using this approach we could more accurately recover the original sample shape by time-of-flight tomography

    The suicide, the assisted suicide and the responsibility of physicians

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    POPOVÁ, L. Suicide, Assisted Suicide, Physicians' Responsibility. Prague 2009. Thesis. Charles University in Prague. Catholic Theological Faculty. Department of Theological Ethics and Theology of Spirituality. Supervisor PhDr. Keywords: suicide, assisted suicide, responsibility, physician, patient The thesis first defines the basic terms and then describes suicide from the ethical perspective as a choice between life and death. It also shows the Christian ethics point of view. Then it focuses on the assisted suicide, which ethically relates to the topic, being a choice between life and death - but also contains suffering and pain in peoples' lives, concerning mainly ill people and dying people. Here, Christian ethics point of view is described, as well. Due to the wide scope of the topic, the following chapter specifies the relation physician-patient, looking closely at the amount of their responsibility during the treatment and at the end of the patient's life, comparing the past and present situation. Then there is a chapter on palliative care, which is, in my opinion, the right approach to the physician-patient relation in the contemporary medicine, and also a kind of a solution when discussing euthanasia or assisted suicide issues. On the basis of interviews, the last chapter takes a look at..

    Sex- and age-dependent genetics of longevity in a heterogeneous mouse population.

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    DNA variants that modulate life span provide insight into determinants of health, disease, and aging. Through analyses in the UM-HET3 mice of the Interventions Testing Program (ITP), we detected a sex-independent quantitative trait locus (QTL) on chromosome 12 and identified sex-specific QTLs, some of which we detected only in older mice. Similar relations between life history and longevity were uncovered in mice and humans, underscoring the importance of early access to nutrients and early growth. We identified common age- and sex-specific genetic effects on gene expression that we integrated with model organism and human data to create a hypothesis-building interactive resource of prioritized longevity and body weight genes. Finally, we validated Hipk1, Ddost, Hspg2, Fgd6, and Pdk1 as conserved longevity genes using Caenorhabditis elegans life-span experiments
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