117 research outputs found

    New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"

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    Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2×14.32 \times 14.3 m. In 2014, this experiment has been run with an outstanding sensitivity, using an 18.5 W continuous wave laser emitting in the green at the single wavelength of 532 nm. No regenerated photons have been detected after the wall, pushing the limits for the existence of axions and ALPs down to an unprecedented level for such a type of laboratory experiment. The di-photon couplings of possible pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit to be less than 3.51083.5\cdot 10^{-8} GeV1^{-1} and 3.21083.2\cdot 10^{-8} GeV1^{-1}, respectively, at 95% Confidence Level.Comment: 6 pages, 6 figure

    Latest Results of the OSQAR Photon Regeneration Experiment for Axion-Like Particle Search

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    The OSQAR photon regeneration experiment searches for pseudoscalar and scalar axion-like particles by the method of "Light Shining Through a Wall", based on the assumption that these weakly interacting sub-eV particles couple to two photons to give rise to quantum oscillations with optical photons in strong magnetic field. No excess of events has been observed, which constrains the di-photon coupling strength of both pseudoscalar and scalar particles down to 5.71085.7 \cdot 10^{-8} GeV1^{-1} in the massless limit. This result is the most stringent constraint on the di-photon coupling strength ever achieved in laboratory experiments.Comment: 6 pages, 5 figures. appears in Proceedings of the 10th PATRAS Workshop on Axions, WIMPs and WISPs (2014

    An epigenetic clock for gestational age at birth based on blood methylation data

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    Background: Gestational age is often used as a proxy for developmental maturity by clinicians and researchers alike. DNA methylation has previously been shown to be associated with age and has been used to accurately estimate chronological age in children and adults. In the current study, we examine whether DNA methylation in cord blood can be used to estimate gestational age at birth. Results: We find that gestational age can be accurately estimated from DNA methylation of neonatal cord blood and blood spot samples. We calculate a DNA methylation gestational age using 148 CpG sites selected through elastic net regression in six training datasets. We evaluate predictive accuracy in nine testing datasets and find that the accuracy of the DNA methylation gestational age is consistent with that of gestational age estimates based on established methods, such as ultrasound. We also find that an increased DNA methylation gestational age relative to clinical gestational age is associated with birthweight independent of gestational age, sex, and ancestry. Conclusions: DNA methylation can be used to accurately estimate gestational age at or near birth and may provide additional information relevant to developmental stage. Further studies of this predictor are warranted to determine its utility in clinical settings and for research purposes. When clinical estimates are available this measure may increase accuracy in the testing of hypotheses related to developmental age and other early life circumstances

    A sociological dilemma: race, segregation, and US sociology

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    US sociology has been historically segregated in that, at least until the 1960s, there were two distinct institutionally organized traditions of sociological thought – one black and one white. For the most part, however, dominant historiographies have been silent on that segregation and, at best, reproduce it when addressing the US sociological tradition. This is evident in the rarity with which scholars such as WEB Du Bois, E Franklin Frazier, Oliver Cromwell Cox, or other ‘African American Pioneers of Sociology’, as Saint-Arnaud calls them, are presented as core sociological voices within histories of the discipline. This article addresses the absence of African American sociologists from the US sociological canon and, further, discusses the implications of this absence for our understanding of core sociological concepts. With regard to the latter, the article focuses in particular on the debates around equality and emancipation and discusses the ways in which our understanding of these concepts could be extended by taking into account the work of African American sociologists and their different interpretations of core themes

    Physics potential of the International Axion Observatory (IAXO)

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    We review the physics potential of a next generation search for solar axions:the International Axion Observatory (IAXO). Endowed with a sensitivity todiscover axion-like particles (ALPs) with a coupling to photons as small asgaγ1012g_{a\gamma}\sim 10^{-12} GeV1^{-1}, or to electrons gaeg_{ae}\sim1013^{-13},IAXO has the potential to find the QCD axion in the 1 meV\sim1 eV mass rangewhere it solves the strong CP problem, can account for the cold dark matter ofthe Universe and be responsible for the anomalous cooling observed in a numberof stellar systems. At the same time, IAXO will have enough sensitivity todetect lower mass axions invoked to explain: 1) the origin of the anomalous"transparency" of the Universe to gamma-rays, 2) the observed soft X-ray excessfrom galaxy clusters or 3) some inflationary models. In addition, we reviewstring theory axions with parameters accessible by IAXO and discuss theirpotential role in cosmology as Dark Matter and Dark Radiation as well as theirconnections to the above mentioned conundrums

    Applying polygenic risk scoring for psychiatric disorders to a large family with bipolar disorder and major depressive disorder

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    Psychiatric disorders are thought to have a complex genetic pathology consisting of interplay of common and rare variation. Traditionally, pedigrees are used to shed light on the latter only, while here we discuss the application of polygenic risk scores to also highlight patterns of common genetic risk. We analyze polygenic risk scores for psychiatric disorders in a large pedigree (n similar to 260) in which 30% of family members suffer from major depressive disorder or bipolar disorder. Studying patterns of assortative mating and anticipation, it appears increased polygenic risk is contributed by affected individuals who married into the family, resulting in an increasing genetic risk over generations. This may explain the observation of anticipation in mood disorders, whereby onset is earlier and the severity increases over the generations of a family. Joint analyses of rare and common variation may be a powerful way to understand the familial genetics of psychiatric disorders
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