405 research outputs found

    Nonlinear system modeling based on constrained Volterra series estimates

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    A simple nonlinear system modeling algorithm designed to work with limited \emph{a priori }knowledge and short data records, is examined. It creates an empirical Volterra series-based model of a system using an lql_{q}-constrained least squares algorithm with q≄1q\geq 1. If the system m(⋅)m\left( \cdot \right) is a continuous and bounded map with a finite memory no longer than some known τ\tau, then (for a DD parameter model and for a number of measurements NN) the difference between the resulting model of the system and the best possible theoretical one is guaranteed to be of order N−1ln⁥D\sqrt{N^{-1}\ln D}, even for D≄ND\geq N. The performance of models obtained for q=1,1.5q=1,1.5 and 22 is tested on the Wiener-Hammerstein benchmark system. The results suggest that the models obtained for q>1q>1 are better suited to characterize the nature of the system, while the sparse solutions obtained for q=1q=1 yield smaller error values in terms of input-output behavior

    Conformity and controversies in the diagnosis, staging and follow-up evaluation of canine nodal lymphoma: a systematic review of the last 15 years of published literature

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    Diagnostic methods used in the initial and post-treatment evaluation of canine lymphoma are heterogeneous and can vary within countries and institutions. Accurate reporting of clinical stage and response assessment is crucial in determining the treatment efficacy and predicting prognosis. This study comprises a systematic review of all available canine multicentric lymphoma studies published over 15 years. Data concerning diagnosis, clinical stage evaluation and response assessment procedures were extracted and compared. Sixty-three studies met the eligibility criteria. Fifty-five (87.3%) studies were non-randomized prospective or retrospective studies. The survey results also expose variations in diagnostic criteria and treatment response assessment in canine multicentric lymphoma. Variations in staging procedures performed and recorded led to an unquantifiable heterogeneity among patients in and between studies, making it difficult to compare treatment efficacies. Awareness of this inconsistency of procedure and reporting may help in the design of future clinical trials

    Features and prognostic impact of distant metastases in 45 dogs with de novo stage IV cutaneous mast cell tumours: A prospective study

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    BACKGROUND: Distant metastases in dogs with cutaneous mast cell tumors (cMCT) are rare and incurable. The aims of this prospective study were to clarify the clinico-pathological features of stage IV cMCTs and to identify possible prognostic factors for progression-free interval (PFI) and survival time (ST). MATERIAL AND METHODS: Dogs were eligible for recruitment if they had a previously untreated, histologically confirmed cMCT and if they underwent complete staging demonstrating stage IV disease. Dogs were uniformly followed-up, whereas treatment was not standardized and included no therapy, surgery, radiation therapy, chemotherapy, tyrosine-kinase inhibitors or a combination of these. RESULTS: 45 dogs with stage IV cMCT were enrolled. All dogs had distant metastatic disease, and 41 (91.1%) dogs had also metastasis in the regional lymph node. Histopathological grade and mutational status greatly varied among dogs. Median ST was 110 days. Notably, PFI and ST were independent of well-known prognostic factors, including anatomic site, histological grade, and mutational status. Conversely, tumor diameter >3\u2009cm, more than 2 metastatic sites, bone marrow infiltration, and lack of tumor control at the primary site were confirmed to be negative prognostic factors by multivariate analysis. CONCLUSION: Currently, there is no satisfactory treatment for stage IV cMCT. Asymptomatic dogs with tumor diameter <3\u2009cm and a low tumor burden, without bone marrow infiltration may be candidates for multimodal treatment. Stage IV dogs without lymph node metastasis may enjoy a surprisingly prolonged survival. The achievement of local tumor control seems to predict a better outcome in dogs with stage IV cMCT

    Complete compensation of criss-cross deflection in a negative ion accelerator by magnetic technique

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    During 2016, a joint experimental campaign was carried out by QST and Consorzio RFX on the Negative Ion Test Stand (NITS) at the QST Naka Fusion Institute, Japan, with the purpose of validating some design solutions adopted in MITICA, which is the full-scale prototype of the ITER NBI, presently under construction at Consorzio RFX, Padova, Italy. The main purpose of the campaign was to test a novel technique, for suppressing the beamlet criss-cross magnetic deflection. This new technique, involving a set of permanent magnets embedded in the Extraction Grid, named Asymmetric Deflection Compensation Magnets (ADCM), is potentially more performing and robust than the traditional electrostatic compensation methods. The results of this first campaign confirmed the effectiveness of the new magnetic configuration in reducing the criss-cross magnetic deflection. Nonetheless, contrary to expectations, a complete deflection correction was not achieved. By analyzing in detail the results, we found indications that a physical process, taking place just upstream of the plasma grid, was giving an important contribution to the final deflection of the negative ion beam. This process appears to be related to the drift of negative ions inside the plasma source, in the presence of a magnetic field transverse to the extraction direction, and results in a non-uniform ion current density extracted at the meniscus. Therefore, the numerical models adopted in the design were improved by including this previously disregarded effect, so as to obtain a much better matching with the experimental results. Based on the results of the first campaign, new permanent magnets were designed and installed on the Extraction Grid of NITS. A second QST-Consorzio RFX joint experimental campaign was then carried out in 2017, demonstrating the complete correction of the criss-cross deflection and confirming the validity of the novel magnetic configuration and of the hypothesis behind the new models. This contribution presents the results of the second joint experimental campaign on NITS along with the overall data analysis of both campaigns, and the description of the improved models. A general picture is given of the relation among magnetic field, beam energy, meniscus non-uniformity and beamlet deflection, constituting a useful database for the design of future machines

    Periarticular histiocytic sarcoma with heart metastasis in a cat

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    A 4-year-old intact female domestic short-haired cat was referred for recommendations about adjuvant medical treatment 1&nbsp;month after left forelimb amputation due to periarticular histiocytic sarcoma (HS). At presentation, physical abnormalities were limited to enlarged ipsilateral superficial cervical and axillary lymph nodes. Routine blood analysis, abdominal ultrasound, and thoracic radiology were unremarkable. The cat initially received lomustine without any adverse events. Four weeks later, the cat developed severe acute respiratory distress. Results of thoracic radiographs and transthoracic echocardiographic analysis were suggestive of pulmonary and heart metastasis. Due to the cat's poor clinical condition and prognosis, the owner elected euthanasia, and a necropsy was performed. Based on gross pathology, histopathology, and immunohistochemistry, an HS with nodal, renal, pulmonary, and heart (right auricular and right ventricular) metastases was diagnosed. This case represents the first description of HS with a heart metastasis in a cat, providing further insight into the clinical course and metastatic behavior of this rare malignant neoplasm. Clinicians should be aware of this site of metastasis and consider HS in the list of differential diagnoses for secondary heart tumors in cats

    Design of the new electromagnetic measurement system for RFX-mod upgrade

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    A major modification of the RFX-mod toroidal load assembly has been decided in order to improve passive MHD control and to minimize the braking torque on the plasma, thus extending the operational space in both RFP and Tokamak configurations. With the removal of the vacuum vessel, the support structure will be modified in order to obtain a new vacuum-tight chamber and the first wall tiles will be directly in front of the passive stabilizing shell inside of it, so increasing both the poloidal cross section and the plasma-shell proximity. This implies the design of a new vacuum fit electromagnetic measurement system. The new local probes will be installed in vacuum onto the copper shell, behind the graphite tiles, and shall operate up to a maximum temperature of 180\ub0C to allow for baking cycles for first wall conditioning. Because of the reduced room available, tri-axial pickup probes have been designed, with the additional advantage of allowing the minimization of alignment errors. The paper describes the detailed design of the new probe set, in particular highlighting advantages and effectiveness of different probe solutions. Preliminary tests carried out on local probe prototypes to characterize their electromagnetic behaviour are also reported

    Prognostic value of pd-l1, pd-1 and cd8a in canine diffuse large b-cell lymphoma detected by rnascope

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    Immune checkpoints are a set of molecules dysregulated in several human and canine cancers and aberrations of the PD-1/PD-L1 axis are often correlated with a worse prognosis. To gain an insight into the role of immune checkpoints in canine diffuse large B-cell lymphoma (cDLBCL), we investigated PD-L1, PD-1 and CD8A expression by RNAscope. Results were correlated with several clinico-pathological features, including treatment, Ki67 index and outcome. A total of 33 dogs treated with chemotherapy (n = 12) or chemoimmunotherapy with APAVAC (n = 21) were included. PD-L1 signal was diffusely distributed among neoplastic cells, whereas PD-1 and CD8A were localized in tumor infiltrating lymphocytes. However, PD-1 mRNA was also retrieved in tumor cells. An association between PD-L1 and PD-1 scores was identified and a higher risk of relapse and lymphoma-related death was found in dogs treated with chemotherapy alone and dogs with higher PD-L1 and PD-1 scores. The correlation between PD-L1 and PD-1 is in line with the mechanism of immune checkpoints in cancers, where neoplastic cells overexpress PD-L1 that, in turn, binds PD-1 receptors in activated TIL. We also found that Ki67 index was significantly increased in dogs with the highest PD-L1 and PD-1 scores, indirectly suggesting a role in promoting tumor proliferation. Finally, even if the biological consequence of PD-1+ tumor cells is unknown, our findings suggest that PD-1 intrinsic expression in cDLBCL might contribute to tumor growth escaping adaptive immunity

    La grande crociata. Il 18 aprile nel Veneto

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    Il fascicolo analizza il tornante decisivo delle lezioni politiche dell'aprile 1948 analizzando la mobilitazione del clero e dell'associazionismo cattolico in alcune province venete

    Vortex dynamics in NbTi films at high frequency and high DC magnetic fields

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    We report on the characterization of NbTi films at ∌ 11 GHz and in DC magnetic fields up to 4 T, performed by means of the coplanar waveguide resonator technique, providing quantitative information about the penetration depth, the complex impedance, and the vortex-motion-induced complex resistivity. This kind of characterization is essential for the development of radiofrequency cavity technology. To access the vortex-pinning parameters, the complex impedance was analyzed within the formalism of the Campbell penetration depth. Measurements in this frequency range allowed us to determine the complete set of vortex-pinning parameters and the flux flow resistivity, both analyzed and discussed in the framework of high-frequency vortex dynamics models. The analysis also benefits from the comparison with results obtained by a dielectric-loaded resonator technique on similar samples and by other ancillary structural and electromagnetic characterization techniques that provide us with a comprehensive picture of the material. It turns out that the normalized flux flow resistivity follows remarkably well the trend predicted by the time dependent Ginzburg-Landau theory, while the pinning constant exhibits a decreasing trend with the field which points to a collective pinning regime
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