144 research outputs found
Enhancement of SSVEPs Classification in BCI-based Wearable Instrumentation Through Machine Learning Techniques
This work addresses the adoption of Machine Learning classifiers and Convolutional Neural Networks to improve the performance of highly wearable, single-channel instrumentation for Brain-Computer Interfaces. The proposed measurement system is based on the classification of Steady-State Visually Evoked Potentials (SSVEPs). In particular, Head-Mounted Displays for Augmented Reality are used to generate and display the flickering stimuli for the SSVEPs elicitation. Four experiments were conducted by employing, in turn, a different Head-Mounted Display. For each experiment, two different algorithms were applied and compared with the state-of-the-art-techniques. Furthermore, the impact of different Augmented Reality technologies in the elicitation and classification of SSVEPs was also explored. The experimental metrological characterization demonstrates (i) that the proposed Machine Learning-based processing strategies provide a significant enhancement of the SSVEP classification accuracy with respect to the state of the art, and (ii) that choosing an adequate Head-Mounted Display is crucial to obtain acceptable performance. Finally, it is also shown that the adoption of inter-subjective validation strategies such as the Leave-One-Subject-Out Cross Validation successfully leads to an increase in the inter-individual 1-σ reproducibility: this, in turn, anticipates an easier development of ready-to-use systems
A ML-based Approach to Enhance Metrological Performance of Wearable Brain-Computer Interfaces
In this paper, the adoption of Machine Learning (ML) classifiers is addressed to improve the performance of highly wearable, single-channel instrumentation for Brain-Computer Interfaces (BCIs). The proposed BCI is based on the classification of Steady-State Visually Evoked Potentials (SSVEPs). In this setup, Augmented Reality Smart Glasses are used to generate and display the flickering stimuli for the SSVEP elicitation. An experimental campaign was conducted on 20 adult volunteers. Successively, a Leave-One-Subject-Out Cross Validation was performed to validate the proposed algorithm. The obtained experimental results demonstrate that suitable ML-based processing strategies outperform the state-of-the-art techniques in terms of classification accuracy. Furthermore, it was also shown that the adoption of an inter-subjective model successfully led to a decrease in the 3-σ uncertainty: this can facilitate future developments of ready-to-use systems
The Urokinase/Urokinase Receptor System in Mast Cells: Effects of its Functional Interaction with fMLF Receptors.
Mast cell and basophils express the high affinity receptor for IgE (FcɛRI) and are primary effector cells of allergic disorders. The urokinase (uPA)-mediated plasminogen activation system is involved in physiological and pathological events based on cell migration and tissue remodelling, such as inflammation, wound healing, angiogenesis and metastasis. uPA is a serine protease that binds uPAR, a high affinity glycosyl-phosphatidyl-inositol (GPI)-anchored receptor. uPAR focuses uPA activity at the cell surface and activates intracellular signaling through lateral interactions with integrins, receptor tyrosine kinases and the G-protein-coupled family of fMLF chemotaxis receptors (FPRs). We investigated the expression of the uPA-uPAR system and its functional interaction with FPRs in human mast cells (MCs). Differently from basophils, MCs produced uPA that was able to induce their chemotaxis. Indeed, MCs also expressed uPAR, both in the intact and in a cleaved form (DII-DIII-uPAR) that can expose, at the N-terminus, the SRSRY sequence, able to interact with FPRs and to mediate cell chemotaxis. MCs also expressed mRNAs for FPRs that were functionally active; indeed, uPA and a soluble peptide (uPAR84-95), containing the SRSRY chemotactic sequence of uPAR and able to interact with FPRs, were able to induce MCs chemotaxis. Thus, uPA is a potent chemoattractant for MCs acting through the exposure of the chemotactic epitope of uPAR, that is an endogenous ligand for FPRs. The same mechanism could be involved in VEGF-A secretion by human MCs, also induced by uPA and uPAR84-95 stimulation
β2-Adrenergic receptor stimulation improves endothelial progenitor cell-mediated ischemic neoangiogenesis
Endothelial progenitor cells (EPCs) are present in the systemic circulation and home to sites of ischemic injury where they promote neoangiogenesis. β2-Adrenergic receptor (β2AR) plays a critical role in vascular tone regulation and neoangiogenesis
The Italian Society of Rheumatology clinical practice guidelines for the management of polymyalgia rheumatica
Objective: to provide evidence-based up-to-date recommendations for the management of patients with a definite diagnosis of polymyalgia rheumatica (PMR). Methods: A systematic literature review was performed to find the existing clinical practice guidelines (CPGs) on PMR and the framework of the Guidelines International Network Adaptation Working Group was used to appraise (AGREE II), synthesize, and customize the recommendations according to the needs of the Italian healthcare context. Rheumatologists on behalf of the Italian Society of Rheumatology (SIR) and from the SIR Epidemiology Unit joined the working group and identified the key health questions on PMR to guide the systematic literature review. Physicians, including general practitioners and specialists, and health professionals who manage PMR in the clinical practice were the target audience. The final recommendations were rated externally by a multi-disciplinary and multi-professional group of stakeholders. Results: From the systematic search in databases (Medline, Embase) and grey literature, 3 CPGs were identified and appraised by two independent raters. Combining the statements and the evidence from these CPGs, 9 recommendations were developed by endorsement or adaptation in response to the initial key health questions. The quality of evidence was graded and the working group discussed the final recommendations in view of their implementation in the Italian healthcare context. Conclusions: In absence of national guidelines so far, these recommendations are the first to provide guidance for the management of patients with a diagnosis of PMR in Italy and they are expected to ensure the best evidence-based clinical practice for this disease
Antiapoptotic Seminal Vesicle Protein IV Induces Histamine Release from Human FcεRI+ Cells.
BACKGROUND: Seminal vesicle protein number 4 (SV-IV) is a small, basic, multifunctional, intrinsically disordered secretory protein synthesized in large amounts by rat seminal vesicle epithelium under androgen transcriptional control. SV-IV-immunorelated proteins occur in other rat tissues and in humans.
METHODS: The in vitro effect of SV-IV on human FcepsilonRI+ cells was investigated by standard immunologic, biochemical and molecular biology procedures.
RESULTS: SV-IV-induced histamine release from human basophils and lung mast cells without any influence on leukotriene C(4) release and cell migration. The histamine release rate was slower compared with that induced by anti-IgE, the temperature dependence of the event being similar. SV-IV-induced histamine release was Ca2+-dependent, suggesting a physiological interaction of the protein with FcepsilonRI+ cells. SV-IV and anti-IgE acted synergistically on the histamine release. SV-IV did not induce de novo synthesis of cytokines and growth factors (transforming growth factor-beta(1), interleukin-10, interleukin-13, tumor necrosis factor-alpha, vascular endothelial growth factor A) in FcεRI+ cells.
CONCLUSIONS: SV-IV protein induces in human FcεRI+ cells the release of histamine, a proinflammatory, antiapoptotic and immunosuppressive biogenic amine. These data: (1) are consistent with the antiapoptotic and immunosuppressive properties of SV-IV; (2) confirm a regulatory feature of SV-IV on mammal inflammatory reactivity by either inhibiting the arachidonate cascade pathway or stimulating proinflammatory cytokine release from lymphocyte/monocytes and histamine from FcεRI+ cells; (3) raise the possibility of a protective role of SV-IV on implanting hemiallogenic blastocysts against maternal reactive oxygen species and immunological attacks at the uterine implantation site
EUSO-SPB1 mission and science
The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of ⪆ 3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search
Measurement of UV light emission of the nighttime Earth by Mini-EUSO for space-based UHECR observations
The JEM-EUSO (Joint Experiment Missions for Extreme Universe Space Observatory) program aims at the realization of the ultra-high energy cosmic ray (UHECR) observation using wide field of view fluorescence detectors in orbit. Ultra-violet (UV) light emission from the atmosphere such as airglow and anthropogenic light on the Earth\u27s surface are the main background for the space-based UHECR observations. The Mini-EUSO mission has been operated on the International Space Station (ISS) since 2019 which is the first space-based experiment for the program. The Mini-EUSO instrument consists of a 25 cm refractive optics and the photo-detector module with the 2304-pixel array of the multi-anode photomultiplier tubes. On the nadir-looking window of the ISS, the instrument is capable of continuously monitoring a ~300 km x 300 km area. In the present work, we report the preliminary result of the measurement of the UV light in the nighttime Earth using the Mini-EUSO data downlinked to the ground. We mapped UV light distribution both locally and globally below the ISS obit. Simulations were also made to characterize the instrument response to diffuse background light. We discuss the impact of such light on space-based UHECR observations and the Mini-EUSO science objectives
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