1,973 research outputs found

    Strong Water Absorption in the Dayside Emission Spectrum of the Planet HD 189733b

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    Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'Hot Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial for understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report on the detection of strong water absorption in a high signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microns and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures might alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat distribution from the dayside to the night side is weak. Reconciling this with the high night side temperature will require a better understanding of atmospheric circulation or possible additional energy sources.Comment: 11 pages, 1 figure, published in Natur

    Uneven Distribution of MHC Class II Epitopes within the Influenza Virus

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    The identification of T cell epitopes is crucial for the understanding of the host immune response during infection. While much is known about the MHC class I-restricted response following influenza virus infection of C57BL/6 mice, with over 16 CD8 epitopes identified to date, less is known about the MHC class II-restricted response. Currently, only a few I-Ab-restricted T helper epitopes have been identified. Therefore, several important questions remain about how many class II epitopes exist in this system and whether these epitopes are evenly distributed within the most abundant viral proteins. In order to address these questions, we analyzed the repertoire of epitopes that drive the CD4b T cell response to influenza virus infection in C57BL/6 (H-2b) mice. Using a panel of overlapping peptides from each of the viral proteins we show that approximately 20–30 epitopes drive the CD4 T cell response and that the majority of these peptides are derived from the NP and HA proteins. We were also able to demonstrate that vaccination with one of the newly identified epitopes, HA211–225/Ab, resulted in increased epitope-specific T cell numbers and a significant reduction in viral titers following influenza virus challenge

    Uneven Distribution of MHC Class II Epitopes within the Influenza Virus

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    The identification of T cell epitopes is crucial for the understanding of the host immune response during infection. While much is known about the MHC class I-restricted response following influenza virus infection of C57BL/6 mice, with over 16 CD8 epitopes identified to date, less is known about the MHC class II-restricted response. Currently, only a few I-Ab-restricted T helper epitopes have been identified. Therefore, several important questions remain about how many class II epitopes exist in this system and whether these epitopes are evenly distributed within the most abundant viral proteins. In order to address these questions, we analyzed the repertoire of epitopes that drive the CD4b T cell response to influenza virus infection in C57BL/6 (H-2b) mice. Using a panel of overlapping peptides from each of the viral proteins we show that approximately 20–30 epitopes drive the CD4 T cell response and that the majority of these peptides are derived from the NP and HA proteins. We were also able to demonstrate that vaccination with one of the newly identified epitopes, HA211–225/Ab, resulted in increased epitope-specific T cell numbers and a significant reduction in viral titers following influenza virus challenge

    A united statement of the global chiropractic research community against the pseudoscientific claim that chiropractic care boosts immunity.

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    BACKGROUND: In the midst of the coronavirus pandemic, the International Chiropractors Association (ICA) posted reports claiming that chiropractic care can impact the immune system. These claims clash with recommendations from the World Health Organization and World Federation of Chiropractic. We discuss the scientific validity of the claims made in these ICA reports. MAIN BODY: We reviewed the two reports posted by the ICA on their website on March 20 and March 28, 2020. We explored the method used to develop the claim that chiropractic adjustments impact the immune system and discuss the scientific merit of that claim. We provide a response to the ICA reports and explain why this claim lacks scientific credibility and is dangerous to the public. More than 150 researchers from 11 countries reviewed and endorsed our response. CONCLUSION: In their reports, the ICA provided no valid clinical scientific evidence that chiropractic care can impact the immune system. We call on regulatory authorities and professional leaders to take robust political and regulatory action against those claiming that chiropractic adjustments have a clinical impact on the immune system

    Measurement of the prompt J/psi and psi(2S) polarizations in pp collisions at sqrt(s) = 7 TeV

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    The polarizations of prompt J/psi and psi(2S) mesons are measured in proton-proton collisions at sqrt(s) = 7 TeV, using a dimuon data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.9 inverse femtobarns. The prompt J/psi and psi(2S) polarization parameters lambda[theta], lambda[phi], and lambda[theta, phi], as well as the frame-invariant quantity lambda(tilde), are measured from the dimuon decay angular distributions in three different polarization frames. The J/psi results are obtained in the transverse momentum range 14 < pt < 70 GeV, in the rapidity intervals abs(y) < 0.6 and 0.6 < abs(y) < 1.2. The corresponding psi(2S) results cover 14 < pt < 50 GeV and include a third rapidity bin, 1.2 < abs(y) < 1.5. No evidence of large transverse or longitudinal polarizations is seen in these kinematic regions, which extend much beyond those previously explored

    Schadevergoeding bij overlijden: een stoel die een soort tafeltje is

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    In het aansprakelijkheidsrecht heeft een benadeelde in beginsel recht op volledige vergoeding van zijn schade. De gevolgen van de schadetoebrengende gebeurtenis dienen zoveel als mogelijk te worden weggenomen of te worden gecompenseerd. Daarbij wordt gekeken naar de situatie waarin de benadeelde zou hebben verkeerd indien de schadetoebrengende gebeurtenis niet zou hebben plaatsgevonden. Dat is bij overlijden per definitie problematisch. Er is iemand weggevallen, wat vele gevolgen heeft. De schade als gevolg van het overlijden komt maar beperkt voor vergoeding in aanmerking. In artikel 6:108 BW is een drietal beperkingen te vinden. Het gaat hier om beperkingen ten aanzien van de aard van de schade, de kring van gerechtigden en de omvang van de schade. Daarbij hinkt het recht op schadevergoeding bij overlijden op twee gedachten. Aan de ene kant is er het aansprakelijkheidsrecht, maar de geleden schade komt niet volledig voor vergoeding in aanmerking. Aan de andere kant is er het recht op alimentatie uit het familierecht, maar dat wordt bij overlijden niet consequent toegepast. De motieven voor de beperkingen van het recht op schadevergoeding zijn achterhaald en niet (langer) overtuigend. Het recht is niet bij de tijd, het sluit niet aan bij de maatschappelijke ontwikkelingen. De beperkingen die het recht op schadevergoeding bij overlijden in de huidige samenleving met zich meebrengt zorgen voor complexe methoden om de nabestaanden tegemoet te komen en oogsten daardoor veel kritiek. In deze bijdrage wordt die kritiek besproken. De bijdrage wordt afgesloten met enkele denkrichtingen voor nader onderzoek
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