1,688 research outputs found

    Reconstruction of non-prompt charmed baryon Λc with boosted decision trees technique

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    L'esperimento ALICE studia la fisica dell'interazione forte a estreme densità di energia attraverso la collisione di ioni pesanti. In tali condizioni è possibile la formazione dello stato della materia chiamato plasma di quark e gluoni. A causa della ridotta vita media di tale stato, lo studio è molto complesso ed è pertanto possibile condurlo solo in modo indiretto sulla base delle modalità di raffreddamento e dalle particelle rilasciate nel processo. Uno dei principali metodi d’indagine è lo studio di adroni contenenti quark pesanti (charm e beauty) e di come queste particelle, prodotte nei primi stadi della collisione, interagiscono con questo stato della materia. L'obiettivo della tesi è la ricostruzione del barione charmato Λc e la distinzione del segnale non-prompt da quello prompt attraverso la tecnica dei Boosted Decision Trees. L'analisi è stata condotta attraverso l'approccio di analisi multivariata in cui è possibile considerare le proprietà di più eventi contemporaneamente, ricavando il maggior numero di informazioni attraverso tecniche di machine learning

    A variational autoencoder application for real-time anomaly detection at CMS

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    Despite providing invaluable data in the field of High Energy Physics, towards higher luminosity runs the Large Hadron Collider (LHC) will face challenges in discovering interesting results through conventional methods used in previous run periods. Among the proposed approaches, the one we focus on in this thesis work – in collaboration with CERN teams, involves the use of a joint variational autoencoder (JointVAE) machine learning model, trained on known physics processes to identify anomalous events that correspond to previously unidentified physics signatures. By doing so, this method does not rely on any specific new physics signatures and can detect anomalous events in an unsupervised manner, complementing the traditional LHC search tactics that rely on model-dependent hypothesis testing. The algorithm produces a list of anomalous events, which experimental collaborations will examine and eventually confirm as new physics phenomena. Furthermore, repetitive event topologies in the dataset can inspire new physics model building and experimental searches. Implementing this algorithm in the trigger system of LHC experiments can detect previously unnoticed anomalous events, thus broadening the discovery potential of the LHC. This thesis presents a method for implementing the JointVAE model, for real-time anomaly detection in the Compact Muon Solenoid (CMS) experiment. Among the challenges of implementing machine learning models in fast applications, such as the trigger system of the LHC experiments, low latency and reduced resource consumption are essential. Therefore, the JointVAE model has been studied for its implementation feasibility in Field-Programmable Gate Arrays (FPGAs), utilizing a tool based on High-Level Synthesis (HLS) named HLS4ML. The tool, combined with the quantization of neural networks, will reduce the model size, latency, and energy consumption

    Effect of lower-limb joint models on subject-specific musculoskeletal models and simulations of daily motor activities

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    Understanding the validity of using musculoskeletal models is critical, making important to assess how model parameters affect predictions. In particular, assumptions on joint models can affect predictions from simulations of movement, and the identification of image-based joints is unavoidably affected by uncertainty that can decrease the benefits of increasing model complexity. We evaluated the effect of different lower-limb joint models on muscle and joint contact forces during four motor tasks, and assessed the sensitivity to the uncertainties in the identification of anatomical four-bar-linkage joints. Three MRI-based musculoskeletal models having different knee and ankle joint models were created and used for the purpose. Model predictions were compared against a baseline model including simpler and widely-adopted joints. In addition, a probabilistic analysis was performed by perturbing four-bar-linkage joint parameters according to their uncertainty. The differences between models depended on the motor task analyzed, and there could be marked differences at peak loading (up to 2.40 BW at the knee and 1.54 BW at the ankle), although they were rather small over the motor task cycles (up to 0.59 BW at the knee and 0.31 BW at the ankle). The model including more degrees of freedom showed more discrepancies in predicted muscle activations compared to measured muscle activity. Further, including image-based four-bar-linkages was robust to simulate walking, chair rise and stair ascent, but not stair descent (peak standard deviation of 2.66 BW), suggesting that joint model complexity should be set according to the imaging dataset available and the intended application, performing sensitivity analyses

    The Importance of Worst-Case Memory Contention Analysis for Heterogeneous SoCs

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    Memory interference may heavily inflate task execution times in Heterogeneous Systems-on-Chips (HeSoCs). Knowing worst-case interference is consequently fundamental for supporting the correct execution of time-sensitive applications. In most of the literature, worst-case interference is assumed to be generated by, and therefore is estimated through read-intensive synthetic workloads with no caching. Yet these workloads do not always generate worst-case interference. This is the consequence of the general results reported in this work. By testing on multiple architectures, we determined that the highest interference generation traffic pattern is actually hardware dependant, and that making assumptions could lead to a severe underestimation of the worst-case (in our case, of more than 9x).Comment: Accepted for presentation at the CPS workshop 2023 (http://www.cpsschool.eu/cps-workshop

    Occurrence and exposure of 3-monochloropropanediol diesters in edible oils and oil-based foodstuffs from the Spanish market

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    During the industrial refining process of edible oils and the manufacture of oil-based foodstuff, contaminants such as 3-monochloropropanediol (3-MCPD) fatty acid diesters can be produced. One hundred samples of different edible oils and related fatty food purchased from local Spanish markets were analyzed to evaluate the occurrence of these contaminants. Data of seven 3-MCPD diesters together with corresponding total 3-MCPD equivalents are presented. The procedure is based on a modified QuEChERS protocol followed by LC-MS/MS analysis. Extra virgin olive oil (EVOO) and unrefined oils did not contain detectable levels of the target analytes. The highest levels of 3-MCPD diesters were found in palm oils, for 1,2-Dilinoleoyl-3-chloropropanediol (LILI) and 1–2-Bispalmitoyl-3-chloropropanediol (PAPA) with concentrations close to 10 mg kg−1 and in the lipid fraction of margarines (8.09, 3.77 and 3.72 mg kg−1 for LILI, PAPA and 1-Oleoyl-2-linoleoyl-3-chloropropanediol (OLLI), respectively).Spanish Ministry of Science and Innovation (Project AGL-2014-53647-R) and FEDER fund

    Migraine Prevention through Ketogenic Diet: More than Body Mass Composition Changes

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    The ketogenic diet (KD) is gaining attention as a preventive treatment for migraine, which is sustained by many pre-clinical and clinical data. KD is also used for weight loss, and there is a relation between migraine and weight excess, but it is speculated that KD efficacy on migraine may go beyond this effect. We conducted a retrospective observational study on 23 migraine patients who received a KD and were evaluated at the baseline and then after 3 months both from a neurological and a nutritional point of view, including body mass composition analysis. We observed a reduction in monthly headache days (12.5 ± 9.5 vs. 6.7 ± 8.6; p < 0.001) and in days of acute medication intake (11.06 ± 9.37 vs. 4.93 ± 7.99; p = 0.008). We also observed a reduction in patients’ weight (73.8 ± 15.2 vs. 68.4 ± 14.6; p < 0.001) and BMI (26.9 ± 6.2 vs. 23.7 ± 8.1; p < 0.001) with a decrement of the fat mass (28.6 ± 12.5 vs. 20.6 ± 9.8; p < 0.001). Patients who responded to KD and those who did not had no differences with respect to weight or fat mass loss. These data corroborate the utilization of KD as a preventive treatment for migraine and suggest that the efficacy of such an intervention is not only due to weight or fat mass loss but probably relies on other mechanisms specific to KD

    DNA interaction and cytotoxicity studies of new ruthenium(II) cyclopentadienyl derivative complexescontaining heteroaromatic ligands

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    Four ruthenium(II) complexes with the formula [Ru(eta(5)-C(5)H(5))(PP)L][CF(3)SO(3)], being (PP = two triphenylphosphine molecules), L = 1-benzylimidazole, 1; (PP = two triphenylphosphine molecules), L = 2,2'bipyridine, 2; (PP = two triphenylphosphine molecules), L = 4-Methylpyridine, 3; (PP = 1,2-bis(diphenylphosphine) ethane), L = 4-Methylpyridine, 4, were prepared, in view to evaluate their potentialities as antitumor agents. The compounds were completely characterized by NMR spectroscopy and their crystal and molecular structures were determined by X-ray diffraction. Electrochemical studies were carried out giving for all the compounds quasi-reversible processes. The images obtained by atomic force microscopy (AFM) suggest interaction with pBR322 plasmid DNA. Measurements of the viscosity of solutions of free DNA and DNA incubated with different concentrations of the compounds confirmed this interaction. The cytotoxicity of compounds 1234 was much higher than that of cisplatin against human leukemia cancer cells (HL-60 cells). IC(50) values for all the compounds are in the range of submicromolar amounts. Apoptotic death percentage was also studied resulting similar than that of cisplatin. (C) 2010 Elsevier Inc. All rights reserved

    New iron(II) cyclopentadienyl derivative complexes: synthesis and antitumor activity against human leukemia cancer cells

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    A new family of 'FeII(h5-C5H5)' half sandwich compounds bearing a N-heteroaromatic ligand coordinated to the iron center by a nitrile functional group has been synthesized and fully characterized by NMR and UVeVis spectroscopy. X-ray analysis of single crystal was achieved for complexes 1 and 3, which crystallized in the monoclinic P21/c and monoclinic P21/n space groups, respectively. Studies of interaction of these five new complexes with plasmid pBR322 DNA by atomic force microscopy showed very strong and different types of interaction. Antiproliferative tests were examined on human leukemia cancer cells (HL-60) using the MTT assay, and the IC50 values revealed excellent antiproliferative activity compared to cisplatin

    Population pharmacokinetic modeling of benznidazole in Brazilian patients with chronic Chagas disease

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    The present study aimed to establish a population pharmacokinetic (PopPK) modeling of benznidazole (BZD) in Brazilian patients with chronic Chagas disease. This was part of a Brazilian prospective cohort study with eight patients diagnosed with Chagas disease during the beginning of BZD treatment up to the 60th day. On the 15th day of treatment, a blood sampling was collected and analyzed. A one-compartment PK model was developed using Pmetrics. Patients with an average age of 50.3 (SD: 6.2) years old, 6 female patients and 2 males, 70.2 kg (14.2), receiving a 5 mg/Kg/day dose were included. PK parameters estimated for CL, V and Ka were 6.27 L/h, 38.97 L and 1.66 h-1, respectively. This is the first study to establish a population pharmacokinetic modeling of BZD in Brazilian patients with chronic Chagas disease. Therefore, further studies are needed to obtain the complete characterization of BZD pharmacokinetics
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