2,216 research outputs found
FROM THE FIRST ELECTROMAGNETIC WAVE DISTANCE MEASURING SYSTEM TO GALILEO AND THE MASS MARKET
La tecnica dei sistemi satellitari di determinazione delle coordinate geografiche di un
punto e di navigazione, si basa su sistemi impiegati durante la seconda Guerra Mondiale
e diffusi in campo del rilevamento cartografico, alla sua fine. La nota ne riassume sinteticamente
la evoluzione.The present mass market geographic coordinate determination and satellite navigation
systems are based on methods developed during the Second World War and
introduced in Cartography immediately after. The present paper reviews shortly the
evolution
Virtual twins of nonlinear vibrating multiphysics microstructures: physics-based versus deep learning-based approaches
Micro-Electro-Mechanical-Systems are complex structures, often involving
nonlinearites of geometric and multiphysics nature, that are used as sensors
and actuators in countless applications. Starting from full-order
representations, we apply deep learning techniques to generate accurate,
efficient and real-time reduced order models to be used as virtual twin for the
simulation and optimization of higher-level complex systems. We extensively
test the reliability of the proposed procedures on micromirrors, arches and
gyroscopes, also displaying intricate dynamical evolutions like internal
resonances. In particular, we discuss the accuracy of the deep learning
technique and its ability to replicate and converge to the invariant manifolds
predicted using the recently developed direct parametrization approach that
allows extracting the nonlinear normal modes of large finite element models.
Finally, by addressing an electromechanical gyroscope, we show that the
non-intrusive deep learning approach generalizes easily to complex multiphysics
problem
Reduced order modeling of parametrized systems through autoencoders and SINDy approach: continuation of periodic solutions
Highly accurate simulations of complex phenomena governed by partial
differential equations (PDEs) typically require intrusive methods and entail
expensive computational costs, which might become prohibitive when
approximating steady-state solutions of PDEs for multiple combinations of
control parameters and initial conditions. Therefore, constructing efficient
reduced order models (ROMs) that enable accurate but fast predictions, while
retaining the dynamical characteristics of the physical phenomenon as
parameters vary, is of paramount importance. In this work, a data-driven,
non-intrusive framework which combines ROM construction with reduced dynamics
identification, is presented. Starting from a limited amount of full order
solutions, the proposed approach leverages autoencoder neural networks with
parametric sparse identification of nonlinear dynamics (SINDy) to construct a
low-dimensional dynamical model. This model can be queried to efficiently
compute full-time solutions at new parameter instances, as well as directly fed
to continuation algorithms. These aim at tracking the evolution of periodic
steady-state responses as functions of system parameters, avoiding the
computation of the transient phase, and allowing to detect instabilities and
bifurcations. Featuring an explicit and parametrized modeling of the reduced
dynamics, the proposed data-driven framework presents remarkable capabilities
to generalize with respect to both time and parameters. Applications to
structural mechanics and fluid dynamics problems illustrate the effectiveness
and accuracy of the proposed method
Anandamide Suppresses Proliferation and Cytokine Release from Primary Human T-Lymphocytes Mainly via CB2 Receptors
Anandamide (AEA) is an endogenous lipid mediator that exerts several effects in the brain as well as in peripheral tissues. These effects are mediated mainly by two types of cannabinoid receptors, named CB(1)R and CB(2)R, making AEA a prominent member of the "endocannabinoid" family. Also immune cells express CB(1) and CB(2) receptors, and possess the whole machinery responsible for endocannabinoid metabolism. Not surprisingly, evidence has been accumulated showing manifold roles of endocannabinoids in the modulation of the immune system. However, details of such a modulation have not yet been disclosed in primary human T-cells.In this investigation we used flow cytometry and ELISA tests, in order to show that AEA suppresses proliferation and release of cytokines like IL-2, TNF-alpha and INF-gamma from activated human peripheral T-lymphocytes. However, AEA did not exert any cytotoxic effect on T-cells. The immunosuppression induced by AEA was mainly dependent on CB(2)R, since it could be mimicked by the CB(2)R selective agonist JWH-015, and could be blocked by the specific CB(2)R antagonist SR144528. Instead the selective CB(1)R agonist ACEA, or the selective CB(1)R antagonist SR141716, were ineffective. Furthermore, we demonstrated an unprecedented immunosuppressive effect of AEA on IL-17 production, a typical cytokine that is released from the unique CD4+ T-cell subset T-helper 17.Overall, our study investigates for the first time the effects of the endocannabinoid AEA on primary human T-lymphocytes, demonstrating that it is a powerful modulator of immune cell functions. In particular, not only we clarify that CB(2)R mediates the immunosuppressive activity of AEA, but we are the first to describe such an immunosuppressive effect on the newly identified Th-17 cells. These findings might be of crucial importance for the rational design of new endocannabinoid-based immunotherapeutic approaches
Psychological, Behavioral, and Interpersonal Effects and Clinical Implications for Health Systems of the Coronavirus (COVID-19) Pandemic: A Call for Research
The novel coronavirus disease (COVID-19) emerged at the end of 2019 and was classified as a pandemic by the World Health Organization (WHO) on March 11, 2020. Both the COVID-19 emergency and the extraordinary measures to contain it have negatively affected the life of billions of people and have threatened individuals and nations. One of the main goals of clinical and health psychology during this pandemic is to investigate the behavioral, cognitive, emotional, and psychobiological responses to the COVID-19 emergency as well as to the preventive measures that have been imposed by governments to limit the contagion, such as social isolation. Psychological research has the responsibility to deliver sound empirical evidence to inform public health policies and to support and advise governments and policymakers in their introduction of sustainable, feasible, and cost-efficient prevention and intervention guidelines. Hence, the goal of this call for research is to stimulate theoretical discussions and empirical investigations on the bio-psycho-social impacts of COVID-19 for individuals, groups, and nations. We invite contributions that address the challenges that the COVID-19 emergency has imposed on couples, families, and social systems. In addition, we call for studies that assess the specific effects of the COVID-19 pandemic on highly vulnerable populations such as children, adolescents, pregnant women, patients suffering from chronic and life-threatening conditions, healthcare workers, and elderly citizens. Papers focusing on the impact of emotion regulation and coping strategies are encouraged. Original research, data reports, study protocols, single case reports and community case studies, theoretical perspectives, and viewpoints are invited to help improve our understanding of the COVID-19 pandemic
"Mi voglio bene": a pediatrician-based randomized controlled trial for the prevention of obesity in Italian preschool children
<p>Abstract</p> <p>Background</p> <p>The first years of life are crucial to start preventive interventions that can have an impact on lifestyle and later overweight and obesity. Under the Italian National Health System (INHS), children are cared for by family pediatricians who perform health balances at regular intervals. The Italian Society of Preventive and Social Pediatrics (SIPPS) has designed a randomized controlled trial (RCT) to evaluate the effectiveness of family pediatricians for the prevention of childhood obesity in preschool children. We report the rationale and protocol of such trial, named the "Mi voglio bene" ("I love myself") study.</p> <p>Methods</p> <p>"Mi voglio bene" is a parallel-arm RCT. Family pediatricians willing to participate to the trial will be randomly assigned to a control group and to an experimental group. The control group will provide the usual standard of care while the experimental group will implement 10 preventive actions (promotion of breastfeeding, avoidance of solid foods, control of protein intake, avoidance of sugar-sweetened beverages, avoidance of bottle, active means of transportation, identification of early adiposity rebound, limitation of television viewing, promotion of movement, and teaching portion size) at 10 time points during a 6-yr follow-up. The main outcome measures is the prevalence of overweight and obesity at 6 years of age. The experimental intervention is expected to reduce the prevalence of overweight and obesity from 25% to 20% and the study requires a total of 3610 children. Each pediatrician will enroll 30 consecutive newborns into the study so that a total of 120 pediatricians will participate to the study.</p> <p>Discussion</p> <p>"Mi voglio bene" is expected to provide important information for the INHS and possibly other institutional child care settings about the effectiveness of a pediatrician-based approach to the prevention of childhood obesity. We published this study protocol with the aim of opening a discussion with all people interested in fighting childhood obesity and to receive useful criticisms.</p
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Tau mutations serve as a novel risk factor for cancer
In addition to its well-recognized role in neurodegeneration, tau participates in maintenance of genome stability and chromosome integrity. In particular, peripheral cells from patients affected by frontotemporal lobar degeneration carrying a mutation in tau gene (genetic tauopathies), as well as cells from animal models, show chromosome numerical and structural aberrations, chromatin anomalies, and a propensity toward abnormal recombination. As genome instability is tightly linked to cancer development, we hypothesized that mutated tau may be a susceptibility factor for cancer. Here we conducted a retrospective cohort study comparing cancer incidence in families affected by genetic tauopathies to control families. Additionally, we carried out a bioinformatics analysis to highlight pathways associated with the tau protein interactome. We report that the risk of developing cancer is significantly higher in families affected by genetic tauopathies, and a high proportion of tau protein interactors are involved in cellular processes particularly relevant to cancer. These findings disclose a novel role of tau as a risk factor for cancer, providing new insights in the various pathological roles of mutated tau
Laparoscopic Cytoreduction Combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Peritoneal Surface Malignancies (PSM): Italian PSM Oncoteam Evidence and Literature Review
Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has gained increasing acceptance in clinical practice. Performing CRS and HIPEC laparoscopically represents a challenging and intriguing technical evolution. However, the experiences are limited, and the evidence is low. This retrospective analysis was performed on patients treated with laparoscopic CRS-HIPEC within the Italian Peritoneal Surface Malignancies Oncoteam. Clinical, perioperative, and follow-up data were extracted and collected on prospectively maintained databases. We added a systematic review according to the PRISMA method for English-language articles through April 2022 using the keywords laparoscopic, hyperthermic, HIPEC, and chemotherapy. From 2016 to 2022, fourteen patients were treated with Lap-CRS-HIPEC with curative intent within the Italian centers. No conversion to open was observed. The median duration of surgery was 487.5 min. The median Peritoneal Cancer Index (PCI) was 3, and complete cytoreduction was achieved in all patients. Two patients (14.3%) had major postoperative complications, one requiring reintervention. After a median follow-up of 16.9 months, eleven patients were alive without disease (78.6%), two patients developed recurrence (14.3%), and one patient died for unrelated causes (7.1%). The literature review confirmed these results. In conclusion, current evidence shows that Lap-CRS-HIPEC is feasible, safe, and associated with a favorable outcome in selected patients. An accurate patient selection will continue to be paramount in choosing this treatment
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