364 research outputs found

    Descriptions and explanations in historical linguistics

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    Descriptions and explanations in historical linguistics. The principles underlying language change involve structural, sociocultural and neurocognitive factors, as languages are complex and coherent systems governed by algorithms, at the intersection of nature and nurture. Therefore, in order to understand these principles it is necessary to adopt an interdisciplinary approach in which linguistics could benefit from philology, sociohistorical sciences, physiology and neurosciences. Moreover, there is a need for disentangling the actuation problem from the transition problem, to explain the patterns of language change and its effect on the systems involved. KEYWORDS: Actuation and transition of language change, markedness, frequency, memory systemThe principles underlying language change involve structural, sociocultural and neurocognitive factors, as languages are complex and coherent systems governed by algorithms, at the intersection of nature and nurture. Therefore, in order to understand these principles it is necessary to adopt an interdisciplinary approach in which linguistics could benefit from philology, sociohistorical sciences, physiology and neurosciences. Moreover, there is a need for disentangling the actuation problem from the transition problem, to explain the patterns of language change and its effect on the systems involved. KEYWORDS: Actuation and transition of language change, markedness, frequency, memory syste

    Development of a new CEDAR for kaon identification at the NA62 experiment at CERN

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    The NA62 experiment at CERN utilises a differential Cherenkov counter with achromatic ring focus (CEDAR) for tagging kaons within an unseparated monochromatic beam of charged hadrons. The CEDAR-H detector was developed to minimise the amount of material in the path of the beam by using hydrogen gas as the radiator medium. The detector was shown to satisfy the kaon tagging requirements in a test-beam before installation and commissioning at the experiment. The CEDAR-H performance was measured using NA62 data collected in 2023

    ChPT tests at the NA48 and NA62 experiments at CERN

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    The NA48/2 Collaboration at CERN has accumulated unprecedented statistics of rare kaon decays in the Ke4 modes: Ke4(+-) (K±π+πe±νK^\pm \to \pi^+ \pi^- e^\pm \nu) and Ke4(00) (K±π0π0e±νK^\pm \to \pi^0 \pi^0 e^\pm \nu) with nearly one percent background contamination. The detailed study of form factors and branching rates, based on these data, has been completed recently. The results brings new inputs to low energy strong interactions description and tests of Chiral Perturbation Theory (ChPT) and lattice QCD calculations. In particular, new data support the ChPT prediction for a cusp in the π0π0\pi^0\pi^0 invariant mass spectrum at the two charged pions threshold for Ke4(00) decay. New final results from an analysis of about 400 K±π±γγK^\pm \to \pi^\pm \gamma \gamma rare decay candidates collected by the NA48/2 and NA62 experiments at CERN during low intensity runs with minimum bias trigger configurations are presented. The results include a model-independent decay rate measurement and fits to ChPT description.Comment: XIIth International Conference on Heavy Quarks and Leptons 2014, Mainz, German

    Recent NA48/2 and NA62 results

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    The NA48/2 Collaboration at CERN has accumulated and analysed unprecedented statistics of rare kaon decays in the Ke4K_{e4} modes: Ke4(+)K_{e4}(+-) (K±π+πe±νK^\pm \to \pi^+ \pi^- e^\pm \nu) and Ke4(00)K_{e4}(00) (K±π0π0e±νK^\pm \to \pi^0 \pi^0 e^\pm \nu) with nearly one percent background contamination. It leads to the improved measurement of branching fractions and detailed form factor studies. New final results from the analysis of 381 K±π±γγK^\pm \to \pi^\pm \gamma \gamma rare decay candidates collected by the NA48/2 and NA62 experiments at CERN are presented. The results include a decay rate measurement and fits to Chiral Perturbation Theory (ChPT) description.Comment: Prepared for the Proceedings of "Moriond QCD and High Energy Interactions. March 22-29 2014." conferenc

    Prospects for K+π+ννˉK^+ \to \pi^+ \nu \bar{ \nu } at CERN in NA62

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    The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay K+π+ννˉK^+ \to \pi^+ \nu \bar{ \nu }, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV/c.The detector and analysis technique are described here.Comment: 8 pages for proceedings of 50 Years of CP

    Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

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    Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM

    Study of the K+- to pi+- gamma gamma decay by the NA62 experiment

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    A study of the dynamics of the rare decay K±π±γγK^\pm\to\pi^\pm\gamma\gamma has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.117.4\pm1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2z=(m_{\gamma\gamma}/m_K)^2>0.2 is BMI(z>0.2)=(0.965±0.063)×106{\cal B}_{\rm MI}(z>0.2) = (0.965 \pm 0.063) \times 10^{-6}, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(Kπγγ)=(1.003±0.056)×106{\cal B}(K_{\pi\gamma\gamma}) = (1.003 \pm 0.056) \times 10^{-6}. A detailed comparison of the results with the previous measurements is performed.A study of the dynamics of the rare decay K±π±γγK^\pm\to\pi^\pm\gamma\gamma has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.117.4\pm1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2z=(m_{\gamma\gamma}/m_K)^2>0.2 is BMI(z>0.2)=(0.965±0.063)×106{\cal B}_{\rm MI}(z>0.2) = (0.965 \pm 0.063) \times 10^{-6}, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(Kπγγ)=(1.003±0.056)×106{\cal B}(K_{\pi\gamma\gamma}) = (1.003 \pm 0.056) \times 10^{-6}. A detailed comparison of the results with the previous measurements is performed.A study of the dynamics of the rare decay K±→π±γγ has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 Collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2 is BMI(z>0.2)=(0.965±0.063)×10−6 , and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(Kπγγ)=(1.003±0.056)×10−6 . A detailed comparison of the results with the previous measurements is performed

    Neutral pion form factor measurement at NA62

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    The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from 1.05 × 106 fully reconstructed π0 Dalitz decay is presented. The limits on dark photon production in π0 decays from the earlier kaon experiment at CERN, NA48/2, are also reported

    Discovery of Therapeutic Approaches for Polyglutamine Diseases: A Summary of Recent Efforts

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    Polyglutamine (PolyQ) diseases are a group of neurodegenerative disorders caused by the expansion of cytosine-adenine-guanine (CAG) trinucleotide repeats in the coding region of specific genes. This leads to the production of pathogenic proteins containing critically expanded tracts of glutamines. Although polyQ diseases are individually rare, the fact that these nine diseases are irreversibly progressive over 10 to 30 years, severely impairing and ultimately fatal, usually implicating the full-time patient support by a caregiver for long time periods, makes their economic and social impact quite significant. This has led several researchers worldwide to investigate the pathogenic mechanism(s) and therapeutic strategies for polyQ diseases. Although research in the field has grown notably in the last decades, we are still far from having an effective treatment to offer patients, and the decision of which compounds should be translated to the clinics may be very challenging. In this review, we provide a comprehensive and critical overview of the most recent drug discovery efforts in the field of polyQ diseases, including the most relevant findings emerging from two different types of approaches-hypothesis-based candidate molecule testing and hypothesis-free unbiased drug screenings. We hereby summarize and reflect on the preclinical studies as well as all the clinical trials performed to date, aiming to provide a useful framework for increasingly successful future drug discovery and development efforts.Project ON.2 SR&TD Integrated Program (NORTE-07-0124-FEDER-000021), co-funded by North Portugal Regional Operational Program (ON.2-O Novo Norte), under the National Strategic Reference Framework, through the European Regional Development Fund (ERDF) and also supported by Fundação para a Ciência e Tecnologia through the project POCI-01-0145-FEDER-016818 (PTDC/NEU-NMC/3648/2014)info:eu-repo/semantics/publishedVersio
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