456 research outputs found

    Biological Principles in Self-Organization of Young Brain - Viewed from Kohonen Model

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    Variants of the Kohonen model are proposed to study biological principles of self-organization in a model of young brain. We suggest a function to measure aquired knowledge and use it to auto-adapt the topology of neuronal connectivity, yielding substantial organizational improvement relative to the standard model. In the early phase of organization with most intense learning, we observe that neural connectivity is of Small World type, which is very efficient to organize neurons in response to stimuli. In analogy to human brain where pruning of neural connectivity (and neuron cell death) occurs in early life, this feature is present also in our model, which is found to stabilize neuronal response to stimuli

    A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

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    Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained within the MAGIC experiment using a new technique for the reduction of the background. Particle showers produced by gamma rays show a different temporal distribution with respect to showers produced by hadrons; the background due to accidental counts shows no dependence on time. Such novel strategy can increase the sensitivity of present instruments.Comment: 4 pages, 3 figures, Proc. of the 9th Int. Syposium "Frontiers of Fundamental and Computational Physics" (FFP9), (AIP, Melville, New York, 2008, in press

    Organization of the Euclid Data Processing: Dealing with Complexity

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    The data processing development and operations for the Euclid mission (part of the ESA Cosmic Vision 2015-2025 Plan) is distributed within a Consortium composed of 14 countries and 1300+ persons: this imposes a high degree of complexity to the design and implementation of the data processing facilities. The focus of this paper is on the efforts to define an organisational structure capable of handling in manageable terms such a complexity

    Open Transactions on Shared Memory

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    Transactional memory has arisen as a good way for solving many of the issues of lock-based programming. However, most implementations admit isolated transactions only, which are not adequate when we have to coordinate communicating processes. To this end, in this paper we present OCTM, an Haskell-like language with open transactions over shared transactional memory: processes can join transactions at runtime just by accessing to shared variables. Thus a transaction can co-operate with the environment through shared variables, but if it is rolled-back, also all its effects on the environment are retracted. For proving the expressive power of TCCS we give an implementation of TCCS, a CCS-like calculus with open transactions

    Main Lobe Control of a Beam Tilting Antenna Array Laid on a Deformable Surface

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    The projection method (PM) is a simple and low-cost pattern recovery technique that already proved its effectiveness in retrieving the radiation properties of different types of arrays that change shape in time. However, when dealing with deformable beam-tilting arrays, this method requires to compute new compensating phase shifts every time that the main lobe is steered, since these shifts depend on both the deformation geometry and the steering angle. This tight requirement causes additional signal processing and complicates the prediction of the array behavior, especially if the deformation geometry is not a priori known: this can be an issue since the PM is mainly used for simple and low-cost systems. In this letter, we propose a simplification of this technique for beam-tilting arrays that requires only basic signal processing. In fact the phase shifts that we use are the sum of two components: one can be directly extracted from strain sensor data that measure surface deformation and the other one can be precomputed according to basic antenna theory. The effectiveness of our approach has been tested on two antennas: a 4 × 4 array (trough full-wave simulations and measurements) and on an 8 × 8 array (trough full-wave simulations) placed on a doubly wedge-shaped surface with a beam tilt up to 40 degrees

    What to do in an oncology department to face the new COVID-19 era challenges?

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    9noItaly was the first European country to be hit by COVID-19 pandemic. As a consequence, Italian oncologists had to guarantee essential treatments although minimizing exposure to the virus, and accidental infection, of patients and healthcare professionals. As Department of Medical Oncology of the University Hospital of Udine, in this short report, we describe the measures that we have taken, and gradually updated, since February 26, 2020. All accesses to our Oncology facilities are currently regulated by entrance check-points where patients are screened for infections following dedicated algorithms. Up to date, after 6 weeks of systematic execution of swabs no physician, nurse or other individual of the staff has been found positive to COVID-19. Only one patient admitted for therapy has been identified as COVID-19 positive. The aim of our work is to propose a model, made up of a set of operative procedures, that may be adopted by all the oncologists that daily struggle to guarantee safety and care in Oncology during this COVID-19 emergency.openopenGarattini S.K.; Bin A.; Donato R.; Mansutti M.; Rizzato S.; Troiero G.; Candoni A.; Fanin R.; Fasola G.Garattini, S. K.; Bin, A.; Donato, R.; Mansutti, M.; Rizzato, S.; Troiero, G.; Candoni, A.; Fanin, R.; Fasola, G

    The MAGIC Experiment and Its First Results

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    With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray astrophysics. It is sensitive to photons above an energy of 30 GeV. MAGIC started operations in October 2003 and is currently taking data. This report summarizes its main characteristics, its rst results and its potential for physics.Comment: 6 pages, 3 figures, to be published in the Proceedings of the 6th International Symposium ''Frontiers of Fundamental and Computational Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200

    Effects of neoadjuvant trastuzumab, pertuzumab and palbociclib on Ki67 in HER2 and ER-positive breast cancer

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    The crosstalk between estrogen and HER2 receptors and cell-cycle regulation sustains resistance to endocrine therapy of HER2- and hormone receptor-positive breast cancer. We earlier reported that women with HER2 and ER-positive breast cancer receiving neoadjuvant dual HER2-block and palbociclib in the NA-PHER2 trial had Ki67 decrease and 27% pathological complete responses (pCR). We extended NA-PHER2 to Cohort B using dual HER2-block and palbociclib without fulvestrant and report here Ki67 drops at week-2 (mean change 1225.7), at surgery (after 16 weeks, mean change 129.5), high objective response (88.5%) and pCR (19.2%). In Cohort C [Ki67 > 20% and HER2low (IHC 1+/2+ without gene amplification)], women also received fulvestrant, had dramatic Ki67 drop at week 2 ( 1229.5) persisting at surgery ( 1219.3), and objective responses in 78.3%. In view of the favorable tolerability and of the efficacy-predictive value of Ki67 drop at week-2, the chemotherapy-free approach of NA-PHER2 deserves further investigation in HER2 and ER-positive breast cancer. The trial is registered with ClinicalTrials.gov, number NCT02530424

    Feasibility and Predictive Performance of a Triage System for Patients with Cancer During the COVID-19 Pandemic

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    Background: Triage procedures have been implemented to limit hospital access and minimize infection risk among patients with cancer during the coronavirus disease (COVID-19) outbreak. In the absence of prospective evidence, we aimed to evaluate the predictive performance of a triage system in the oncological setting. Materials and Methods: This retrospective cohort study analyzes hospital admissions to the oncology and hematology department of Udine, Italy, during the COVID-19 pandemic (March 30 to April 30, 2020). A total of 3,923 triage procedures were performed, and data of 1,363 individual patients were reviewed. Results: A self-report triage questionnaire identified 6% of triage-positive procedures, with a sensitivity of 66.7% (95% confidence interval [CI], 43.0%–85.4%), a specificity of 94.3% (95% CI, 93.5%–95.0%), and a positive predictive value of 5.9% (95% CI, 4.3%–8.0%) for the identification of patients who were not admitted to the hospital after medical review. Patients with thoracic cancer (odds ratio [OR], 1.69; 95% CI, 1.13–2.53, p =.01), younger age (OR, 1.52; 95% CI, 1.15–2.01, p <.01), and body temperature at admission ≥37°C (OR, 9.52; 95% CI, 5.44–16.6, p <.0001) had increased risk of positive triage. Direct hospital access was warranted to 93.5% of cases, a further 6% was accepted after medical evaluation, whereas 0.5% was refused at admission. Conclusion: A self-report questionnaire has a low positive predictive value to triage patients with cancer and suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) symptoms. Differential diagnosis with tumor- or treatment-related symptoms is always required to avoid unnecessary treatment delays. Body temperature measurement improves the triage process's overall sensitivity, and widespread SARS-CoV-2 testing should be implemented to identify asymptomatic carriers. Implications for Practice: This is the first study to provide data on the predictive performance of a triage system in the oncological setting during the coronavirus disease outbreak. A questionnaire-based triage has a low positive predictive value to triage patients with cancer and suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) symptoms, and a differential diagnosis with tumor- or treatment-related symptoms is mandatory to avoid unnecessary treatment delays. Consequently, adequate recourses should be reallocated for a triage implementation in the oncological setting. Of note, body temperature measurement improves the overall sensitivity of the triage process, and widespread testing for SARS-CoV-2 infection should be implemented to identify asymptomatic carriers

    First- and second-line treatment strategies for hormone-receptor (HR)-positive HER2-negative metastatic breast cancer: A real-world study

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    Background: Endocrine therapy (ET) plus cyclin-dependent-kinases 4/6 inhibitors (CDK4/6i) represents the standard treatment for luminal-metastatic breast cancer (MBC). However, prospective head-to-head comparisons are still lacking for 1st line (L) options, and it is still crucial to define the best strategy between 1st and 2nd L. Materials and methods: 717 consecutive luminal-MBC pts treated between 2008 and 2020 were analyzed at the Oncology Department of Aviano and Udine, Italy. Differences about survival outcomes (OS, PFS and PPS) were tested by log-rank test. The attrition rate (AR) between 1st and 2ndL was calculated. Results: At 1stL, pts were treated with ET (49%), chemotherapy (CT) (31%) and ET-CDKi (20%) while, at 2ndL, 33% received ET, 33% CT and 8% ET-CDKi. Overall AR was 10%, 7% for CT, 8% for ET and 17% for ET-CDKi. By multivariate analysis, 1stL ET-CDK4/6i showed a better mPFS1 and OS. Moreover, 2ndL ET-CDK4/6i demonstrated better mPFS2 compared to ET and CT. Notably, 1stL ET-CDKi resulted in higher mPFS than 2ndL ET-CDKi. Intriguingly, 1stL ET-CDK4/6i was associated with worse mPPS compared to CT and ET. Secondarily, 1stL ET-CDK4/6i followed by CT had worse OS compared to 1stL ET-CDK4/6i followed by ET. Notably, none of baseline characteristics at 2ndL influenced 2ndL treatment choice (ET vs. CT) after ET-CDKi. Conclusion: Our real-world data demonstrated that ET-CDKi represents the best option for 1stL luminal-MBC compared to ET and CT. Also, the present study pointed out that 2ndL ET, potentially combined with other molecules, could be a feasible option after CDK4/6i failure, postponing CT on later lines
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