Modeling and analysis of a flexible spinning Euler-Bernoulli beam with centrifugal stiffening and softening: A Linear Fractional Representation approach with application to spinning spacecraft

The derivation of a linear fractional representation (LFR) model for a flexible, spinning and uniform Euler-Bernoulli beam is accomplished using the {Lagrange} technique, fully capturing the centrifugal force generated by the spinning motion and accounting for its dependence on the angular velocity. This six degrees of freedom (DOF) model accounts for the behavior of deflection in the moving body frame, encompassing the bending, traction and torsion dynamics. The model is also designed to be compliant with the Two-Input-Two-Output Port (TITOP) approach, which offers the possibility to model complex multibody mechanical systems, while keeping the uncertain nature of the plant and condensing all the possible mechanical configurations in a single LFR. To evaluate the effectiveness of the model, various scenarios are considered and their results are tabulated. These scenarios include uniform beams with fixed root boundary conditions for different values of tip mass, root offset and angular velocity. The results from the analysis of the uniform cantilever beam are compared with solutions found in the literature and obtained from a commercial finite element software. Ultimately, this paper presents a multibody model for a spinning spacecraft mission scenario. A comprehensive analysis of the system dynamics is conducted, providing insights into the behavior of the spacecraft under spinning conditions

Analyzing a fake news authorship network

This project synthesizes a set of 246 fake news websites previously identified in three earlier research projects. From this dataset, we extract a set of all authors who have written for these sites in 2016. This authorcentric dataset is itself a contribution that will allow future analysis of the fake news ecosystem. Based on the data we collected, we construct a network of fake news sites, linking them if they shared a common author. Our analysis shows a tight cluster of author-sharing sites, with a small core set of sites sharing dozens of authors

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

La censura nel film «Il Leone del deserto di Mustapha Akkad». Il cinema contro gli " italiani brava gente".

Lo studio sii propone di analizzare le motivazioni e le conseguenze della censurain Italia del filmIl leone del deserto del regista siro-americano Mustapha Akkad. La pellicola, uscitanel 1981e finanziata in parte dal governo di Gheddafi, ripercorre la storia di Omar al-Mukhtar, il “leone del deserto”, il fiero combattente assunto a simbolo della resistenza libicache si oppose e contrastò l’esercito fascista in Cirenaica.Attraverso il punto di vista del colonizzato, Il leone del deserto propone una rivisitazione del passato coloniale italiano, sottolineando le atrocità commesse e distruggendo il mito degli «italiani brava gente».Considerato di forte impronta anti-italiana, accusato di ledere l'onore dell'esercito, il film non ottenne il visto della censura per essere proiettato in Italia. Solo nel 2009, in concomitanza con la visita a Roma del governatore libico, la tv privata Sky, lo trasmise operando delle modifiche.Se la proiezione nelle sale cinematografiche italiane non fu possibile per molti anni, in Libia il film venne trasmesso dalla tv anche più volte al giorno. È un dato significativo che induce a riflettere su almeno tre aspetti:-le asimmetrie postcoloniali :da una parte l’Italia ha coltivato una memoria distorta della parentesi africana, dall'altra i libici non dimenticano la violenza, la subordinazione economica e politica collegata all’occupazione italiana. -la rimozione del colonialismo italiano. Presupposto da cui parte la nostra indagine è che questo episodio di censura si inserisca nel prolungato silenzio che ha fatto seguito alla fine dell’impresa coloniale italiana, un'impresache, seppur limitata nel tempo e nello spazio,ha generato un’eredità non priva diposizioni nostalgiche estrumentalizzazioni ideologiche. La mancata diffusione del film di Akkad è stato un atto deliberato per occultare le prove delle violenze commesse nella «quarta sponda».-L'importanza di accedere a diverse rappresentazioni, a controstorie, per rielaborare la memoria collettiva, anche a rischio di intaccare la dignità nazionale

Encapsulation of Upconversion Nanoparticles in Periodic Mesoporous Organosilicas

International audience(1) Background: Nanomedicine has recently emerged as a promising field, particularly for cancer theranostics. In this context, nanoparticles designed for imaging and therapeutic applications are of interest. We, therefore, studied the encapsulation of upconverting nanoparticles in mesoporous organosilica nanoparticles. Indeed, mesoporous organosilica nanoparticles have been shown to be very efficient for drug delivery, and upconverting nanoparticles are interesting for near-infrared and X-ray computed tomography imaging, depending on the matrix used. (2) Methods: Two different upconverting-based nanoparticles were synthesized with Yb 3+-Er 3+ as the upconverting system and NaYF 4 or BaLuF 5 as the matrix. The encapsulation of these nanoparticles was studied through the sol-gel procedure with bis(triethoxysilyl)ethylene and bis(triethoxysilyl)ethane in the presence of CTAB. (3) Results: with bis(triethoxysilyl)ethylene, BaLuF 5 : Yb 3+-Er 3+ , nanoparticles were not encapsulated, but anchored on the surface of the obtained mesoporous nanorods BaLuF 5 : Yb 3+-Er 3+ @Ethylene. With bis(triethoxysilyl)ethane, BaLuF 5 : Yb 3+-Er 3+ and NaYF 4 : Yb 3+-Er 3+ nanoparticles were encapsulated in the mesoporous cubic structure leading to BaLuF 5 : Yb 3+-Er 3+ @Ethane and NaYF 4 : Yb 3+-Er 3+ @Ethane, respectively. (4) Conclusions: upconversion nanoparticles were located on the surface of mesoporous nanorods obtained by hydrolysis polycondensation of bis(triethoxysilyl)ethylene, whereas encapsulation occurred with bis(triethoxysilyl)ethane. The later nanoparticles NaYF 4 : Yb 3+-Er 3+ @Ethane or BaLuF 5 : Yb 3+-Er 3+ @Ethane were promising for applications with cancer cell imaging or X-ray-computed tomography respectively

Kawasaki Disease in the Time of COVID-19 and MIS-C: The International Kawasaki Disease Registry.

BACKGROUND: Patients with multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) have overlapping clinical features. We compared demographics, clinical presentation, management, and outcomes of patients according to evidence of previous SARS-CoV-2 infection. METHODS: The International Kawasaki Disease Registry (IKDR) enrolled KD and MIS-C patients from sites in North, Central, and South America, Europe, Asia, and the Middle East. Evidence of previous infection was defined as: Positive (household contact or positive polymerase chain reaction [PCR]/serology), Possible (suggestive clinical features of MIS-C and/or KD with negative PCR or serology but not both), Negative (negative PCR and serology and no known exposure), and Unknown (incomplete testing and no known exposure). RESULTS: Of 2345 enrolled patients SARS-CoV-2 status was Positive for 1541 (66%) patients, Possible for 89 (4%), Negative for 404 (17%) and Unknown for 311 (13%). Clinical outcomes varied significantly among the groups, with more patients in the Positive/Possible groups presenting with shock, having admission to intensive care, receiving inotropic support, and having longer hospital stays. Regarding cardiac abnormalities, patients in the Positive/Possible groups had a higher prevalence of left ventricular dysfunction, and patients in the Negative and Unknown groups had more severe coronary artery abnormalities. CONCLUSIONS: There appears to be a spectrum of clinical features from MIS-C to KD with a great deal of heterogeneity, and one primary differentiating factor is evidence for previous acute SARS-CoV-2 infection/exposure. SARS-CoV-2 Positive/Possible patients had more severe presentations and required more intensive management, with a greater likelihood of ventricular dysfunction but less severe coronary artery adverse outcomes, in keeping with MIS-C