1,579 research outputs found

    Imaging of Mechanically Induced Thermal Heat Patterns

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    Imaging information obtained from nondestructive tests is becoming more widely investigated and developed. Imaging obviously has the potential to provide a more easily interpreted outcome of a nondestructive test, leading to more rapid and correct evaluation of the state of the examined material. This work presents one aspect of the field of imaging — developing a thermal image of the surface of a material subjected to mechanical vibrations. The technique of vibrothermography has been under investigation in our laboratory for several years, especially as applied to advanced composite materials. We will present in this paper a review of the imaging aspects of the technique, in particular discussing the phenomena responsible for producing a surface heat pattern and the phenomena responsible for obtaining a suitable image of this pattern. Finally, a discussion is given of the possible interpretations which may be made from the image concerning evaluation of the material condition, as may be used in a nondestructive evaluation procedure. Examples will be drawn from a number of tests performed in our laboratory

    Genetics of Menstrual Migraine: The Epidemiological Evidence

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    Approximately one of every three to five women with migraine without aura experience migraine attacks in relation to menstruation. The International Classification of Headache Disorders, 2nd Edition provides appendix diagnoses for pure and menstrually related migraine without aura that need further validation. Probands with menstrual migraine might have more affected relatives than probands with nonmenstrual migraine. However, precise epidemiological, family, and twin data still are lacking

    Are Menstrual and Nonmenstrual Migraine Attacks Different?

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    Migraine is the second most common headache condition next to tension-type headache. Up to one fourth of all women have migraine, and 20% of them experience migraine without aura attack in at least two thirds of their menstrual cycles. The current literature is analyzed in response to the question of whether menstrual and nonmenstrual migraine attacks are different. The different studies provide conflicting results, so it is not possible to answer the question firmly. Future studies should be based on the general population. Collection of both prospective and retrospective data is warranted, and headache diagnosis base on interviews by physicians with interest in headache are more precise than lay interviews or questionnaires

    The conceptual and practical ethical dilemmas of using health discussion board posts as research data.

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    Increasing numbers of people living with a long-term health condition are putting personal health information online, including on discussion boards. Many discussion boards contain material of potential use to researchers; however, it is unclear how this information can and should be used by researchers. To date there has been no evaluation of the views of those individuals sharing health information online regarding the use of their shared information for research purposes

    Three-dimensional femtosecond laser nanolithography of crystals

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    Nanostructuring hard optical crystals has so far been exclusively feasible at their surface, as stress induced crack formation and propagation has rendered high precision volume processes ineffective. We show that the inner chemical etching reactivity of a crystal can be enhanced at the nanoscale by more than five orders of magnitude by means of direct laser writing. The process allows to produce cm-scale arbitrary three-dimensional nanostructures with 100 nm feature sizes inside large crystals in absence of brittle fracture. To showcase the unique potential of the technique, we fabricate photonic structures such as sub-wavelength diffraction gratings and nanostructured optical waveguides capable of sustaining sub-wavelength propagating modes inside yttrium aluminum garnet crystals. This technique could enable the transfer of concepts from nanophotonics to the fields of solid state lasers and crystal optics.Comment: Submitted Manuscript and Supplementary Informatio

    HST imaging of the dusty filaments and nucleus swirl in NGC4696 at the centre of the Centaurus Cluster

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    Narrow-band HST imaging has resolved the detailed internal structure of the 10 kpc diameter H alpha+[NII] emission line nebulosity in NGC4696, the central galaxy in the nearby Centaurus cluster, showing that the dusty, molecular, filaments have a width of about 60pc. Optical morphology and velocity measurements indicate that the filaments are dragged out by the bubbling action of the radio source as part of the AGN feedback cycle. Using the drag force we find that the magnetic field in the filaments is in approximate pressure equipartition with the hot gas. The filamentary nature of the cold gas continues inward, swirling around and within the Bondi accretion radius of the central black hole, revealing the magnetic nature of the gas flows in massive elliptical galaxies. HST imaging resolves the magnetic, dusty, molecular filaments at the centre of the Centaurus cluster to a swirl around and within the Bondi radius.This is the accepted manuscript. It is currently embargoed pending publication

    CD209 in inflammatory bowel disease: a case-control study in the Spanish population

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    <p>Abstract</p> <p>Background</p> <p>The etiology of Ulcerative Colitis (UC) and Crohn's Disease (CD), considered together as Inflammatory Bowel Diseases (IBD), involves environmental and genetic factors. Although some genes are already known, the genetics underlying these diseases is complex and new candidates are continuously emerging. The <it>CD209 </it>gene is located in a region linked previously to IBD and a <it>CD209 </it>functional polymorphism (rs4804803) has been associated to other inflammatory conditions. Our aim was to study the potential involvement of this <it>CD209 </it>variant in IBD susceptibility.</p> <p>Methods</p> <p>We performed a case-control study with 515 CD patients, 497 UC patients and 731 healthy controls, all of them white Spaniards. Samples were typed for the <it>CD209 </it>single nucleotide polymorphism (SNP) rs4804803 by TaqMan technology. Frequency comparisons were performed using χ<sup>2 </sup>tests.</p> <p>Results</p> <p>No association between <it>CD209 </it>and UC or CD was observed initially. However, stratification of UC patients by <it>HLA-DR3 </it>status, a strong protective allele, showed that carriage of the <it>CD209</it>_G allele could increase susceptibility in the subgroup of <it>HLA-DR3</it>-positive individuals (p = 0.03 OR = 1.77 95% CI 1.04–3.02, <it>vs. </it>controls).</p> <p>Conclusion</p> <p>A functional variant in the <it>CD209 </it>gene, rs4804803, does not seem to be influencing Crohn's disease susceptibility. However, it could be involved in the etiology or pathology of Ulcerative Colitis in <it>HLA-DR3</it>-positive individuals but further studies are necessary.</p

    The plight of the sense-making ape

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    This is a selective review of the published literature on object-choice tasks, where participants use directional cues to find hidden objects. This literature comprises the efforts of researchers to make sense of the sense-making capacities of our nearest living relatives. This chapter is written to highlight some nonsensical conclusions that frequently emerge from this research. The data suggest that when apes are given approximately the same sense-making opportunities as we provide our children, then they will easily make sense of our social signals. The ubiquity of nonsensical contemporary scientific claims to the effect that humans are essentially--or inherently--more capable than other great apes in the understanding of simple directional cues is, itself, a testament to the power of preconceived ideas on human perception

    Hospitalisation for bed rest for women with a triplet pregnancy: an abandoned randomised controlled trial and meta-analysis

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    BACKGROUND: This abandoned randomised controlled trial assessed the effects of hospitalisation from 24 to 30 weeks gestation for women with a triplet pregnancy on the risk of preterm birth. METHODS: Women with a triplet pregnancy and no other condition necessitating hospital admission were approached for participation in the study, and randomised to either antenatal hospitalisation (hospitalised group), or to routine antenatal care (control group). The randomisation schedule used variable blocks with stratification by parity, and a researcher not involved with clinical care contacted by telephone to determine treatment allocation by opening the next in a series of consecutively numbered, opaque, sealed envelopes. Primary study outcomes were preterm birth (defined as birth less than 37 weeks gestation) and very preterm birth (defined as birth less than 34 weeks gestation), and the development of maternal pregnancy induced hypertension. The trial was ceased prior to achieving the calculated sample size due to difficulties in recruitment. The results of this randomised controlled trial were then combined with the results of another comparing bed rest in women with a triplet pregnancy. RESULTS: Seven women with a triplet pregnancy were recruited to the trial, with three randomised to the hospitalisation group, and four to the control group. There were no statistically significant differences between the two groups for the primary outcomes birth before 37 weeks (3/3 hospitalisation group versus 4/4 control group; relative risk (RR) not estimable), birth before 34 weeks (3/3 hospitalisation group versus 2/4 control group; RR 2.00 95% Confidence Intervals (CI) 0.75–5.33) and pregnancy induced hypertension (1/3 hospitalisation group versus 1/4 control group; RR 1.33 95%CI 0.13–13.74). When the results of this trial were incorporated into a meta-analysis with the previous randomised controlled trial assessing hospitalisation and bed rest for women with a triplet pregnancy, (total sample size 26 women and 78 infants), there were no statistically significant differences identified between the two groups. CONCLUSION: The results of this trial and meta-analysis suggest no benefit of routine hospitalisation and bed rest for women with a triplet pregnancy to reduce the risk of preterm birth. The adoption or continuation of a policy of routine hospitalisation and bed rest for women with an uncomplicated triplet pregnancy cannot be recommended
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