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Off-Grid Multi-Snapshot Spectrum Sensing for Cognitive Radar
Get PDFSpectrum sensing is a key aspect of next-generation cognitive radars that make use of the perception-action cycle to improve their performance while endowing cohabitation with other systems. Awareness of the electromagnetic (EM) environment surrounding the radar is demanded to adapt its behavior to the changing scene. 2-D spectrum sensing is usually carried-out on uniformly-spaced grids, over which the angle of arrival (AOA) of diverse (unknown) sources is estimated along with their frequency occupancy. To mitigate the performance degradations of on-grid methods, this paper proposes an off-grid 2-D profile recovery strategy where the atoms are no longer fixed according to a given pool of nominal AOAs, but some flexibility is allowed to infer off-grid angle displacements. Hence, the angle-frequency profile recovery process is formalized as a regularized maximum likelihood (RML) estimation capable of exploiting the inherent block-sparsity of the overall profile. The resulting challenging optimization problem is handled through a maximum block improvement (MBI) based method, which provides an estimate of the three variable blocks involved in the process, viz., noise power, 2-D profile, and angular displacements. Furthermore, in order to enhance the reliability of determining the space-frequency occupancy map and accurately estimating the angle displacements, three refinement strategies for the 2-D spectrum profile are suggested, suitably leveraging Bayesian information criterion (BIC) and false discovery rate (FDR) paradigms. The proposed framework is then validated through numerical simulations in some realistic EM environments, also comparing the three proposed refinement strategies
Unveiling the Relevance of Immune Dysregulation in Disease Pathogenesis: the TR3-56 cell subtype as a Novel Immune- Regulatory Candidate
Get PDFThe immune system protects the body from infections and maintains overall health. This protection involves the activation of a complex process by which the immune response is triggered in response to the presence of pathogens (such as viruses, bacteria, fungi, etc.), foreign substances, or abnormal cells (e.g., cancer). This process, known as "immune activation", involves several cells and immune molecules working in harmony to defend against the pathological threats.
Immune activation is expressed through the innate and adaptive immune responses, each with distinct roles and mechanisms for defending the body.
The innate immune response acts rapidly as a first line of defence, providing immediate but relatively non-specific protection. It does not differentiate among specific pathogens but recognizes common characteristics shared by many, such as certain molecules on their surfaces. Components of the innate immune system include physical barriers like the skin and mucous membranes, as well as cellular and biochemical elements such as phagocytes (white blood cells that engulf and digest pathogens) and natural killer (NK) cells, which target infected or abnormal cells. The innate response often promotes pro-inflammatory phases and is itself triggered by inflammation, aiding in the recruitment of immune cells to infection sites and enhancing overall defence.
The adaptive immune response develops more slowly but is highly specific, targeting particular pathogens and adapting to the microenvironmental conditions during the response. This response is characterized by "immunological memory," a fundamental feature of the adaptive immune system that offers a more effective response upon subsequent encounters with the same pathogen. Indeed, after encountering a specific pathogen, the adaptive immune system "remembers" it and responds more effectively to subsequent exposures. The adaptive response involves specialized white blood cells called B and T lymphocytes. B cells produce and secrete antibodies, which recognize and bind to specific antigens on pathogens, either directly neutralizing them or flagging them for elimination by other immune cells. T cells perform various functions, including assisting B cell functions (T helper, Th), directly killing infected cells (Cytotoxic T Lymphocytes, CTL), and regulating the immune response. The versatility of T cells is crucial for coordinating immune responses, adapting to different challenges, and ensuring an effective but controlled defence against infections and other threats.
Therefore, immune activation is essential for defending the body against infections and other pathological threats. However, it is equally critical that this immune activation is followed by a “controlled shutdown” of the immune responses once the initial threat is neutralized. Without this regulation, prolonged immune activity can lead to unintended damage to the body's own cells, tissues, and organs, resulting in harmful autoimmune responses. This process is called “immune regulation” and plays a vital role in ensuring that the immune system recognizes and tolerates self-components, preventing auto-reactivity and the onset of autoimmune diseases. Therefore, a properly regulated immune system prevents both excessive immune reactions, which can lead to autoimmune diseases or insufficient responses, which can result in chronic infections or cancer. This regulatory process involves multiple mechanisms, including the suppression of overactive immune cells, the production of inhibitory cytokines, and the activation of regulatory cells, all of which are essential for maintaining immune homeostasis and protecting the body from self-inflicted damage.
The main regulatory mechanisms involve immune cells such as regulatory T cells (Tregs), cytokines, and immune checkpoints, which ensure the proper “homeostasis of immune responses”. These elements act in synergy to prevent excessive or autoimmune reactions, ensuring a delicate balance between immune activation and immune tolerance. When these systems malfunction, it leads to dysregulation, contributing to various pathologies, including autoimmune disorders, chronic inflammation, and immune evasion by tumours. Understanding the factors that influence immunoregulation is essential for identifying therapeutic targets to treat immune-related diseases.
This thesis explores the role of the novel candidate for immune-regulation, the TR3-56 cells, in four pathological models: the myelodysplastic syndromes (MDS), chronic lymphocytic leukaemia (CLL), COVID-19, and kidney transplantation, all of which involve balancing immune activation and regulation. The research during the PhD course has been highlighting TR3-56 involvement in immune regulation and disease determinism: i) these cells appear to contribute to immune dysregulation and disease progression by decreasing CTL activation and facilitating immune escape of myelodysplastic clones in MDS haematopoiesis; ii) Expansion of TR3-56 cells is correlated to immune evasion and leukemic spread in CLL, marking them as potential targets for new therapies; iii) Elevated TR3-56 levels in severe cases are associated with high CTL levels and inflammation in COVID- 19, suggesting their role in modulating immune responses during infections; iv) Increased TR3-56 levels correlate with unstable graft control in kidney transplantation, potentially serving as early indicators of immune-mediated graft issues.
Overall, TR3-56 cells play a critical role in managing immune homeostasis and influencing disease outcomes, making them important for understanding and developing targeted therapies for these conditions.
Therefore, the TR3-56 lymphocyte population emerges as a promising candidate for immune regulation. A deeper understanding of their role and functions may offer valuable insights into correcting immune imbalances, potentially making a significant impact in immunotherapy and disease management
Glucose removal from water mixtures at concentrations ranging from 40 to 0.15 w/w%, via CO2 hydrates formation and separated melting
No full textSimilarly to ice, gas hydrates can be used to purify water from contaminants. The removal efficiency depends of several parameters, such as the chemical composition of the contaminant, its geometry and size, its charge and others. The process was tested for water mixtures containing glucose at different concentrations, ranging from 40 to 0.15 w/w%. To process meaningful quantities of water, the production of hydrates must be abundant. Therefore, CO2 hydrates were formed at seven different concentrations within the previously mentioned range. Only the concentrations corresponding to the best performances were selected to carry out experiments finalized at defining the removal efficiency of the process. For this second scope, hydrates were formed again, separated from the remaining liquid phase and then melted. The obtained water was analysed and the concentration of glucose measured. The comparison between the initial and the final concentrations, allowed to define the overall feasibility of the process
A new “sustainability thinking” for land resources, economic growth, and global change in Southern Europe
No full textLuigi Pirandello. Epistolario II (1891-1895)
No full textIl secondo volume dell’Epistolario raccoglie la corrispondenza del quinquennio 1891-1895. Un lustro ricco e intenso, ripercorribile attraverso testimonianze epistolari che consentono di esplorare a fondo le tappe della vita dell’autore agrigentino in un momento segnato, peraltro, da vicende biografiche di estrema importanza, quali il matrimonio e la nascita del primo figlio. Tutti eventi che si intrecciano con la rigogliosa vena artistica del narratore alle prime armi intento a produrre novelle e romanzi a ritmo serrato e a progettare opere su opere che per la maggior parte restano titoli non realizzati, privi di sbocco editoriale. Non per nulla, frustrazione e smarrimento dominano questi anni in cui «labirinto» sembra essere la parola- chiave del mittente.The second volume of the Epistolario collects the correspondence of the
five-year period 1891-1895. A rich and intense five-year period, which can be retraced through epistolary accounts that allow us to explore in depth the stages in the life of the author from Agrigento at a time marked, moreover, by biographical events of extreme importance, such as his marriage and the birth of his first son. All events that intertwine with the luxuriant artistic vein of the fledgling narrator intent on producing novellas and novels at a rapid pace and planning works on works that for the most part remain unrealised titles, devoid of editorial outlet . Not for nothing, frustration and bewilderment dominate these years in which “labyrinth” seems to be the keyword of sender
Modeling climatic, terrain and soil factors using AHP in GIS for grapevines suitability assessment
Get PDFThe study carried out in Matera, Italy, used multi-criteria decision-making techniques and geographic information systems to identify optimal area management for sustainable grape production. Terrain parameters such as temperature, pH, humidity, soil texture, slope, altitude, nutrients and precipitation were considered. ArcGIS maps were created, and the northwest part of the field was identified as a favorable area. Fuzzy maps were generated, and measurements were taken in each area to determine optimal land management. The results revealed that 51% of the area was very highly suitable for agricultural activities, and 49% was considered high suitable. Receiver operating characteristic (ROC) analysis of the AHP results demonstrated a high level of accuracy, as indicated by the area under the curve (AUC). The produced maps indicated a similar trend of increasing zone management priorities for physico-chemicals as depth fluctuate. Additionally, results showed that remote sensing indices were the most important variables to predict physico-chemicals zone management. The study also highlighted that the majority of the area supported plant growth due to favorable temperature and humidity conditions, with only a small portion in the northwest showing less favorable results. By identifying management zones, the study aimed to protect crops, better use of irrigation water and improve yields. This study highlights the potential of integrating satellite remote sensing, GIS technology and AHP as a valuable tool for agricultural land use planners and policy makers in identifying optimal locations for managing grape production. © 2024 The Author(s). Sustainable Development published by ERP Environment and John Wiley & Sons Ltd
The privacy/antitrust curse: insights from GDPR application in competition law proceedings
No full textExploring Industry 4.0’s Role in Sustainable Supply Chains: Perspectives from a Bibliometric Review
No full textKnowledge-based dimensions in Entrepreneurship Education (EE): modelling and practices
No full textEntrepreneurship Education (EE) recently emerged as a relevant factor in fostering entrepreneurial dynamics. Accordingly, scholars and practitioners have widely acknowledged that the exploration and exploitation of knowledge-based dimensions strongly influence the effectiveness of EE. Despite this, a holistic knowledge-based perspective about EE is still missing. To fill this gap, this paper first identifies and categorizes the potential knowledge-based dimensions grounding EE and then provides a set of case studies to show the theoretical framework's application to current real EE programming. The paper combines deductive and inductive approaches. After elaborating a conceptual framework identifying the potential knowledge-based dimensions for EE, it is tested and applied in three real EE programs developed in Italy and in Finland. The study elaborates a dedicated conceptual framework and identifies the potential knowledge asset dimensions grounding EE programs. Then, a multiple case-study analysis enriches the proposed conceptual arguments with empirical evidence. This paper contributes to developing the literature on EE according to a knowledge- based perspective