338 research outputs found

    Relative Burden of Large CNVs on a Range of Neurodevelopmental Phenotypes

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    While numerous studies have implicated copy number variants (CNVs) in a range of neurological phenotypes, the impact relative to disease severity has been difficult to ascertain due to small sample sizes, lack of phenotypic details, and heterogeneity in platforms used for discovery. Using a customized microarray enriched for genomic hotspots, we assayed for large CNVs among 1,227 individuals with various neurological deficits including dyslexia (376), sporadic autism (350), and intellectual disability (ID) (501), as well as 337 controls. We show that the frequency of large CNVs (>1 Mbp) is significantly greater for ID–associated phenotypes compared to autism (p = 9.58×10−11, odds ratio = 4.59), dyslexia (p = 3.81×10−18, odds ratio = 14.45), or controls (p = 2.75×10−17, odds ratio = 13.71). There is a striking difference in the frequency of rare CNVs (>50 kbp) in autism (10%, p = 2.4×10−6, odds ratio = 6) or ID (16%, p = 3.55×10−12, odds ratio = 10) compared to dyslexia (2%) with essentially no difference in large CNV burden among dyslexia patients compared to controls. Rare CNVs were more likely to arise de novo (64%) in ID when compared to autism (40%) or dyslexia (0%). We observed a significantly increased large CNV burden in individuals with ID and multiple congenital anomalies (MCA) compared to ID alone (p = 0.001, odds ratio = 2.54). Our data suggest that large CNV burden positively correlates with the severity of childhood disability: ID with MCA being most severely affected and dyslexics being indistinguishable from controls. When autism without ID was considered separately, the increase in CNV burden was modest compared to controls (p = 0.07, odds ratio = 2.33)

    Towards a muon collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

    The Botanical Record of Archaeobotany Italian Network - BRAIN: a cooperative network, database and website

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    Con autorización de la revista para autores CSIC[EN] The BRAIN (Botanical Records of Archaeobotany Italian Network) database and network was developed by the cooperation of archaeobotanists working on Italian archaeological sites. Examples of recent research including pollen or other plant remains in analytical and synthetic papers are reported as an exemplar reference list. This paper retraces the main steps of the creation of BRAIN, from the scientific need for the first research cooperation to the website which has a free online access since 2015.Peer reviewe

    Study of mitigation strategies of beam-induced background and Higgs boson couplings measurements at a muon collider.

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    Abstract in english: The goals of the scientific program of the Higgs boson physics at Future Colliders are: the improvement of the precision on the fermions and bosons coupling measurements, as deviation from the Standard Model could reveal New Physics, and measurement of Higgs boson self-couplings, that enable to determine the Higgs boson potential. The muon collider is a possible future machine in which these physics goals can be reached with enough precision. Indeed, at the high center of mass energies, in the regime of multi-TeV and with the luminosity conditions that are foreseen for such a machine, the single, double and triple Higgs bosons production rates will be high enough to meet the required precision and determine the Higgs potential. However, physics measurements at muon collider can be strongly affected by the huge amount of background that comes from the muon decays along the beam line. The purpose of this thesis is two fold. The first one is to study the properties of the beam-induced background and the proposed mitigation strategies that are necessary to reduce it, with full detector simulation, at a muon collider. In this environment the reconstruction of physical objects, like hadronic jets produced by the fragmentation of quarks is studied. The second one is the evaluation of the sensitivity on the Standard Model double Higgs production cross section measurement at 3 TeV center of mass energy. This analysis is the foundation for the evaluation of the sensitivity on the determination of the Higgs boson trilinear self-coupling at a muon collider. Abstract in italiano: Gli obiettivi del programma scientifico riguardante la fisica del bosone di Higgs ai collisori futuri sono: un aumento della precisione nelle misure degli accoppiamenti ai fermioni e ai bosoni, poiché deviazioni dal Modello Standard possono rivelare nuova fisica, e le misure degli auto-accoppiamenti del bosone di Higgs, che permettono di determinare il potenziale del bosone di Higgs. Il collisore di muoni è un possibile collisore futuro in cui tali obiettivi possono essere raggiunti con sufficiente precisione. Infatti ad energie del centro di massa, nel range del Multi-TeV, e alle condizioni di luminosità previste per tale collisore, i rate di produzione di singolo, doppio e triplo Higgs sono sufficienti per raggiungere le precisioni richieste e determinare il potenziale di Higgs. Tuttavia, le misure di fisica a un collisore di muoni possono essere affette dall’alto livello di fondo indotto dal fascio che deriva dal decadimento dei muoni lungo la linea di fascio. Questa tesi ha un duplice obiettivo: il primo è di studiare le proprietà del fondo indotto dal fascio e le strategie necessarie per ridurlo tramite una simulazione dell’intero detector del collisore di muoni. In tale contesto la ricostruzione di oggetti fisici come jets adronici prodotti dalla frammentazione dei quark sono studiati. Il secondo è la stima della sensitività sulla misura della sezione d’urto di produzione del doppio Higgs all’energia del centro di massa di 3 TeV. Questa analisi è la base per la stima della sensitività nella determinazione dell’ auto-accoppiamento trilineare del bosone di Higgs a un collisore di muon

    Characterization of the RF plasma in negative ion source NIO1

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    The NIO1 experiment is a negative ion source built at Consorzio RFX, Padua, with the aim to investigate and optimize the negative ion production. With this purpose, a diagnostic of the plasma in the NIO1 source is essential. The study presented here was made with experimental and numerical approaches. The measurements on the plasma were made by using an electrostatic probe. The conditions of the magnetic field, pressure and RF power coupling inside the source were changed during the campaign of measurements, so it was possible to study the plasma parameters for each different conditions. Analysis of the measured data allowed to verify some important aspects on the plasma inside the NIO1 chamber. The numerical simulations are based on the adaption of an existing code to reproduce the conditions of the NIO1 source. The choices made to adapt it and to reproduce in the code some of the conditions created during the measurement campaign in NIO1 are described. The main aspects issued from the comparisons of simulation with experimental results are then shown

    Accuracy and repeatability of QRAPMASTER and MRF-vFA

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    Our purpose is to evaluate bias and repeatability of the quantitative MRI sequences QRAPMASTER, based on steady-state imaging, and variable Flip Angle MRF (MRF-VFA), based on the transient response. Both techniques are assessed with a standardized phantom and five volunteers on 1.5 T and 3 T clinical scanners. All scans were repeated eight times in consecutive weeks. In the phantom, the mean bias±95% confidence interval for T1 values with QRAPMASTER was 10 ± 10% on 1.5 T and 4 ± 13% on 3.0 T. The mean bias for T1 values with MRF-vFA was 21 ± 17% on 1.5 T and 9 ± 9% on 3.0 T. For T2 values the mean bias with QRAPMASTER was 12 ± 3% on 1.5 T and 23 ± 1% on 3.0 T. For T2 values the mean bias with MRF-vFA was 17 ± 1% on 1.5 T and 19 ± 2% on 3.0 T. QRAPMASTER estimated lower T1 and T2 values than MRF-vFA. Repeatability was good with low coefficients of variation (CoV). Mean CoV ± 95% confidence interval for T1 were 3.2 ± 0.4% on 1.5 T and 4.5 ± 0.8% on 3.0 T with QRAPMASTER and 2.7% ± 0.2% on 1.5 T and 2.5 ± 0.2% on 3.0 T with MRF-vFA. For T2 were 3.3 ± 1.9% on 1.5 T and 3.2 ± 0.6% on 3.0 T with QRAPMASTER and 2.0 ± 0.4% on 1.5 T and 5.7 ± 1.0% on 3.0 T with MRF-vFA. The in-vivo T1 and T2 are in the range of values previously reported by other authors. The in-vivo mean CoV ± 95% confidence interval in gray matter were for T1 1.7 ± 0.2% using QRAPMASTER and 0.7 ± 0.5% using MRF-vFA and for T2 were 0.9 ± 0.4% using QRAPMASTER and 2.4 ± 0.5% using MRF-vFA. In white matter were for T1 0.9 ± 0.3% using QRAPMASTER and 1.3 ± 1.1% using MRF-vFA and for T2 were 0.7 ± 0.4% using QRAPMASTER and 2.4 ± 0.4% using MRF-vFA. A GLM analysis showed that the variations in T1 and T2 mainly depend on the field strength and the subject, but not on the follow-up repetition in different days. This confirms the high repeatability of QRAPMASTER and MRF-vFA. In summary, QRAPMASTER and MRF-vFA on both systems were highly repeatable with moderate accuracy, providing results comparable to standard references. While repeatability was similar for both methods, QRAPMASTER was more accurate. QRAPMASTER is a tested commercial product but MRF-vFA is 4.77 times faster, which would ease the inclusion of quantitative relaxometry

    Full Detector Simulation with Unprecedented Background Occupancy at a Muon Collider

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    In recent years, a Muon collider has attracted a lot of interest in the high-energy physics community, thanks to its ability of achieving clean interaction signatures at multi-TeV collision energies in the most cost-effective way. Estimation of the physics potential of such an experiment must take into account the impact of beam-induced background on the detector performance, which has to be carefully evaluated using full detector simulation. Tracing of all the background particles entering the detector region in a single bunch crossing is out of reach for any realistic computing facility due to the unprecedented number of such particles. To make it feasible a number of optimisations have been applied to the detector simulation workflow. This contribution presents an overview of the main characteristics of the beam-induced background at a Muon collider, the detector technologies considered for the experiment and how they are taken into account to strongly reduce the number of irrelevant computations performed during the detector simulation. Special attention is dedicated to the optimisation of track reconstruction with the conformal tracking algorithm in this high-occupancy environment, which is the most computationally demanding part of event reconstruction
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