247 research outputs found
Characterization of optical systems for the ALPS II experiment
ALPS II is a light shining through a wall style experiment that will use the
principle of resonant enhancement to boost the conversion and reconversion
probabilities of photons to relativistic WISPs. This will require the use of
long baseline low-loss optical cavities. Very high power build up factors in
the cavities must be achieved in order to reach the design sensitivity of ALPS
II. This necessitates a number of different sophisticated optical and control
systems to maintain the resonance and ensure maximal coupling between the laser
and the cavity. In this paper we report on the results of the characterization
of these optical systems with a 20 m cavity and discuss the results in the
context of ALPS II
The heterodyne sensing system for the ALPS II search for sub-eV weakly interacting particles
ALPS II, the Any Light Particle Search, is a second-generation Light Shining
through a Wall experiment that hunts for axion-like particles. The experiment
is currently transitioning from the design and construction phase to the
commissioning phase, with science runs expected to start in 2021. ALPS II plans
to use two different sensing schemes to confirm the potential detection of
axion-like particles or to verify an upper limit on their coupling strength to
two photons of . This
paper discusses a heterodyne sensing scheme (HET) which will be the first
scheme deployed to detect the regenerated light. It presents critical details
of the optical layout, the length and alignment sensing scheme, design features
to minimize spurious signals from stray light, as well as several control and
veto channels specific to HET which are needed to commission and operate the
instrument and to calibrate the detector sensitivity.Comment: 12 pages, 5 figure
Citizen Science 2.0 : Data Management Principles to Harness the Power of the Crowd
Citizen science refers to voluntary participation by the general public in scientific endeavors. Although citizen science has a long tradition, the rise of online communities and user-generated web content has the potential to greatly expand its scope and contributions. Citizens spread across a large area will collect more information than an individual researcher can. Because citizen scientists tend to make observations about areas they know well, data are likely to be very detailed. Although the potential for engaging citizen scientists is extensive, there are challenges as well. In this paper we consider one such challenge – creating an environment in which non-experts in a scientific domain can provide appropriate and accurate data regarding their observations. We describe the problem in the context of a research project that includes the development of a website to collect citizen-generated data on the distribution of plants and animals in a geographic region. We propose an approach that can improve the quantity and quality of data collected in such projects by organizing data using instance-based data structures. Potential implications of this approach are discussed and plans for future research to validate the design are described
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Biological, clinical and population relevance of 95 loci for blood lipids.
Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD
Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.
The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD
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