1,124 research outputs found

    Run-3 Commissioning of CMS Online HLT reconstruction using GPUs

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    The software-based High-Level Trigger (HLT) of CMS reduces the data readout rate from 100 kHz (obtained from Level 1 trigger) to around 5 kHz. It makes use of all detector subsystems and runs a streamlined version of CMS reconstruction. Run-2 of the LHC saw the reconstruction algorithms run on a CPU farm. However, the need to have increased computational power as we approach the high luminosity phase of LHC demands the use of Graphical Processing Units (GPUs) to reign in the cost, size and power consumption of the HLT farm. Parallelization of the reconstruction algorithms, on top of the multi-threading functionality introduced in Run-2, allowed parts of the Hadronic Calorimeter (HCAL), Electromagnetic Calorimeter (ECAL) and Pixel Tracker reconstruction to be offloaded to NVIDIA GPUs. In order to ensure the reproducibility of physics results on any machine, the HLT configuration was designed to run seamlessly with and without GPUs, that is, the algorithms were automatically offloaded to a GPU when one was available and otherwise fell back to running on the CPU. This contribution will describe the development of GPU-based algorithms for the HLT and the challenges they presented, along with the comprehensive validation and commissioning activity undertaken by CMS to ensure the successful operations of the new HLT farm

    Measurement of Bell-type inequalities and quantum entanglement from Λ\Lambda-hyperon spin correlations at high energy colliders

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    Spin correlations of Λ\Lambda-hyperons embedded in the QCD strings formed in high-energy collider experiments provide unique insight into their locality and entanglement features. We show from general considerations that while the Clauser-Horne-Shimony-Holt inequality is less stringent for such states, they provide a benchmark for quantum-to-classical transitions induced by varying i) the associated hadron multiplicity, ii) the spin of nucleons, iii) the separation in rapidity between pairs, and iv) the kinematic regimes accessed. These studies also enable the extraction of quantitative measures of quantum entanglement. We first explore such questions within a simple model of a QCD string comprised of singlets of two partial distinguishable fermion flavors and compare analytical results to those obtained on quantum hardware. We further discuss a class of spin Hamiltonians that model the dynamics of Λ\Lambda spin correlations. Prospects for extracting quantum features of QCD strings from hyperon measurements at current and future colliders are outlined.Comment: Revised manuscrip

    The GenoChip: A New Tool for Genetic Anthropology

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    The Genographic Project is an international effort aimed at charting human migratory history. The project is nonprofit and nonmedical, and, through its Legacy Fund, supports locally led efforts to preserve indigenous and traditional cultures. Although the first phase of the project was focused on uniparentally inherited markers on the Y-chromosome and mitochondrial DNA (mtDNA), the current phase focuses on markers from across the entire genome to obtain a more complete understanding of human genetic variation. Although many commercial arrays exist for genome-wide single-nucleotide polymorphism (SNP) genotyping, they were designed for medical genetic studies and contain medically related markers that are inappropriate for global population genetic studies. GenoChip, the Genographic Project’s new genotyping array, was designed to resolve these issues and enable higher resolution research into outstanding questions in genetic anthropology. TheGenoChip includes ancestry informativemarkers obtained for over 450 human populations, an ancient human (Saqqaq), and two archaic hominins (Neanderthal and Denisovan) and was designed to identify all knownY-chromosome andmtDNAhaplogroups. The chip was carefully vetted to avoid inclusion ofmedically relevant markers. To demonstrate its capabilities, we compared the FST distributions of GenoChip SNPs to those of two commercial arrays. Although all arrays yielded similarly shaped (inverse J) FST distributions, the GenoChip autosomal and X-chromosomal distributions had the highestmean FST, attesting to its ability to discern subpopulations. The chip performances are illustrated in a principal component analysis for 14 worldwide populations. In summary, the GenoChip is a dedicated genotyping platform for genetic anthropology. With an unprecedented number of approximately 12,000 Y-chromosomal and approximately 3,300 mtDNA SNPs and over 130,000 autosomal and X-chromosomal SNPswithout any known health,medical, or phenotypic relevance, the GenoChip is a useful tool for genetic anthropology and population genetics

    Neolithic Mitochondrial Haplogroup H Genomes and the Genetic Origins of Europeans

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    Haplogroup H dominates present-day Western European mitochondrial DNA variability (\u3e40%), yet was less common (~19%) among Early Neolithic farmers (~5450 BC) and virtually absent in Mesolithic hunter-gatherers. Here we investigate this major component of the maternal population history of modern Europeans and sequence 39 complete haplogroup H mitochondrial genomes from ancient human remains. We then compare this ‘real-time’ genetic data with cultural changes taking place between the Early Neolithic (~5450 BC) and Bronze Age (~2200 BC) in Central Europe. Our results reveal that the current diversity and distribution of haplogroup H were largely established by the Mid Neolithic (~4000 BC), but with substantial genetic contributions from subsequent pan-European cultures such as the Bell Beakers expanding out of Iberia in the Late Neolithic (~2800 BC). Dated haplogroup H genomes allow us to reconstruct the recent evolutionary history of haplogroup H and reveal a mutation rate 45% higher than current estimates for human mitochondria

    Observation of γγ → ττ in proton-proton collisions and limits on the anomalous electromagnetic moments of the τ lepton

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    The production of a pair of τ leptons via photon–photon fusion, γγ → ττ, is observed for the f irst time in proton–proton collisions, with a significance of 5.3 standard deviations. This observation is based on a data set recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. Events with a pair of τ leptons produced via photon–photon fusion are selected by requiring them to be back-to-back in the azimuthal direction and to have a minimum number of charged hadrons associated with their production vertex. The τ leptons are reconstructed in their leptonic and hadronic decay modes. The measured fiducial cross section of γγ → ττ is σfid obs = 12.4+3.8 −3.1 fb. Constraints are set on the contributions to the anomalous magnetic moment (aτ) and electric dipole moments (dτ) of the τ lepton originating from potential effects of new physics on the γττ vertex: aτ = 0.0009+0.0032 −0.0031 and |dτ| < 2.9×10−17ecm (95% confidence level), consistent with the standard model

    Run-3 Commissioning of CMS Online HLT reconstruction using GPUs

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    The software-based High-Level Trigger (HLT) of CMS reduces the data readout rate from 100 kHz (obtained from Level 1 trigger) to around 5 kHz. It makes use of all detector subsystems and runs a streamlined version of CMS reconstruction. Run-2 of the LHC saw the reconstruction algorithms run on a CPU farm. But the need to have increased computational power as we approach the high luminosity phase of LHC demands the use of Graphical Processing Units (GPUs) to reign in the cost, size and power consumption of the HLT farm. Parallelization of the reconstruction algorithms, on top of the multi-threading functionality introduced in Run2, allowed parts of the Hadronic Calorimeter (HCAL), Electromagnetic Calorimeter (ECAL) and pixel reconstruction to be offloaded to NVIDIA GPUs. In order to ensure the reproducibility of physics results on any machine, the HLT configuration was designed to run seamlessly with and without GPUs, that is, the algorithms were automatically offloaded to a GPU when one was available and otherwise fell back to running on the CPU. This contribution will describe the development of GPU-based algorithms for the HLT and the challenges they presented, along with the comprehensive validation and commissioning activity undertaken by CMS to ensure the successful operations of the new HLT farm

    Rapid detection of human rotavirus using NSP4 gene specific reverse transcription loop-mediated isothermal amplification assay

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    The seasonal outbreaks of human rotavirus (RV) infection occur every winter. Most patients are diagnosed clinically by a rapid latex agglutination detection kit or polymerase chain reaction assays for RV from stool samples, but some problems have been reported on the specificity and sensitivity of such rapid detection assays. To ratify these issues, a sensitive, specific, simple, and rapid nucleic acid based diagnostic method is expected to be introduced and the reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed to detect the RV in human stool samples by incubation at 60 °C for 1 h and amplification was confirmed by electrophoretic laddering, restriction enzyme digestion, and hydroxynapthol blue discoloration. The assay established in this study was found to detect only the RVs and no cross-reaction with other viruses, demonstrating its high specificity. By using serial samples dilution as template, the detection limit of LAMP was 10 times more than that of PCR. The results showed the potential clinical feasibility of RT-LAMP as a useful diagnostic tool for the detection of RV with high sensitivity in comparison to conventional RT-PCR

    Sulfur Doping: Unique Strategy To Improve the Supercapacitive Performance of Carbon Nano-onions

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    Recently, enhancement of the energy density of a supercapacitor is restricted by the inferior capacitance of negative electrodes, which impedes the commercial development of high-performance symmetric and asymmetric supercapacitors. This article introduces the in situ bulk-quantity synthesis of hydrophilic, porous, graphitic sulfur-doped carbon nano-onions (S-CNO) using a facile flame-pyrolysis technique and evaluated its potential applications as a high-performance supercapacitor electrode in a symmetric device configuration. The high-surface wettability in the as-prepared state enables the formation of highly suspended active conducting material S-CNO ink, which eliminates the routine use of binders for the electrode preparation. The as-prepared S-CNO displayed encouraging features for electrochemical energy storage applications with a high specific surface area (950 m2 g–1), ordered mesoporous structure (∼3.9 nm), high S-content (∼3.6 at. %), and substantial electronic conductivity, as indicated by the ∼80% sp2 graphitic carbon content. The in situ sulfur incorporation into the carbon framework of the CNO resulted in a high-polarized surface with well-distributed reversible pseudosites, increasing the electrode–electrolyte interaction and improving the overall conductivity. The S-CNOs showed a specific capacitance of 305 F g–1, an energy density of 10.6 W h kg–1, and a power density of 1004 W kg–1 at an applied current density of 2 A g–1 in a symmetrical two-electrode cell configuration, which is approximately three times higher than that of the pristine CNO-based device in a similar electrochemical testing environment. Even at 11 A g–1, the S-CNO||S-CNO device rendered an energy density (6.1 W h kg–1) at a deliverable power density of 5.5 kW kg–1, indicating a very good rate capability and power management during peak power delivery applications. Furthermore, it showed a high degree of electrochemical reversibility with excellent cycling stability, retaining ∼95% of its initial capacitance after more than 10 000 repetitive charge–discharge cycles at an applied current density of 5 A g–1

    First record of pouched octopus, Cistopus platinoidus in a tropical estuary

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    Octopuses are marine benthic stenohaline organisms that exhibit a short range of migration within marine habitats and avoid brackish or freshwater environments. The present document is the first record of ’pouched octopus’, Cistopus platinoidus Sreeja et al. 2015, from a tropical estuarine system. We collected 15 specimens of C. platinoidus from the set bag nets operated in Narmada estuary, located 40 km away from the river mouth with an in-situ salinity of 17.63. This report is a new finding of an octopus species from a brackish water ecosystem outside its normal inhabitance range to the best of our knowledge
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