136 research outputs found

    The rural architecture of the Duce: the villages of Sicilian latifundium

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    At the end of the '30s the Italian government, a regime of absolute and conservative approach guided by Il Duce, Benito Mussolini, carried out an attempt of regeneration of rural areas: the Colonization of Sicilian Latifundium. The system was based on the rural city of Edward Caracciolo, the father of local town planning. Caracciolo's planning had spread into a network of houses with its farms and services concentrated in rural villages, where schools, churches, police stations, the doctor's surgeries, etc. may be also be found. Despite the government's efforts to reorganize the region, it was not particularly effective for a variety of historical and social reasons, none bigger than the start of World War II which diverted attention and resources from the program. However, today we can find various rural towns in Sicily with many houses that, because of their low use, still retain the architectural and construction features of the period. The author has been conducting scientific research on this topic for several years. He started with the archive "Ente per la Colonizzazione del Latifondo Siciliano" (now called Ente Sviluppo Agricolo) to review the original designs, contracts with companies, ledgers and other administrative documents. Lately, he has been reviewing the personal archives of designers involved in the building program, finding original drawings, letters, sketches, etc. He has also conducted an architectonic and technical survey of the most relevant buildings, studying the possibilities for their reuse. The work is particularly relevant when you consider that the local government has instructed the allocation of structural funds for the refurbishment of these rural villages. It is believed they represent a strategic resource of development of the rural area of Sicily

    The influence of the explosion anisotropies and of the circumstellar medium on the evolution of Supernova Remnants and on particle acceleration at their shocks

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    This thesis is dedicated to the analysis of X-ray observations of supernova remnants (SNRs), complemented with the synthesis of X-ray spectra employing 3-Dimensional Magneto-Hydrodynamic (MHD) models. The primary objective of this work is to acquire a deeper understanding of how the supernova (SN) explosion and the circumstellar medium (CSM) impact both on the evolution of SNRs and on the mechanisms governing particle acceleration.In particular, I address three key challenges: i) investigating the impact of the environment on electron acceleration through the analysis of the non-thermal radiation in the Kepler's SNR, ii) revealing explosion anisotropies and wind residuals in the Vela SNR through the analysis of X-ray observations, iii) predicting the X-ray emission of the fast expanding ejecta in SN 1987A through the synthesis of the XRISM-Resolve spectrum from a dedicated 3D MHD model.Synchrotron X-ray emission in young SNRs serves as a diagnostic tool to explore the population of high-energy electrons accelerated at the shock front and to understand the acceleration process. By conducting a spatially resolved spectral analysis using NuSTAR and XMM-Newton observations of Kepler's SNR, I study the non-thermal emission in hard X-rays, using a synchrotron radiation model in the loss-limited regime.The analysis reveals two distinct regimes of particle acceleration characterized by different Bohm factors.In the northern region, where the shock interacts with a dense CSM, I observe more efficient acceleration compared to the southern region, where the shock velocity is higher, and there are no indications of shock interaction with dense CSM. These results suggest an enhanced efficiency of the acceleration process in regions where the shock-CSM interaction generates an amplified and turbulent magnetic field.In the proposed scenario, the synchrotron cooling time scale aligns with the acceleration time scale. Conversely, the low speed of a shock propagating in a dense medium is expected to increase the acceleration time scale, resulting in a lower maximum electron energy (and fainter non-thermal X-ray flux) for a given SNR age. To deepen this scenario at smaller scales, I investigate the temporal evolution of the synchrotron flux, taking advantage of the two deepest Chandra/ACIS X-ray observations of Kepler's SNR, performed in 2006 and 2014. Analyzing the spectra of different filaments in the northern shell, I measure their proper motion and estimate the ratio between the acceleration time-scale and the synchrotron cooling time.I identify a region with very low shock velocity and find that the acceleration time-scale is longer than the synchrotron cooling time therein. In this region, I measure a significant decrease in flux from 2006 to 2014, thus obtaining the first evidence of fading synchrotron emission in Kepler's SNR. Overall, these results contribute to a coherent understanding of the diverse electron acceleration regimes observed in Kepler's SNR and associated with its expansion into a non-uniform CSM.Core-collapse SNRs have intricate morphologies arising from inherent asymmetries in the SN explosion and the propagation of explosion shock waves in highly heterogeneous environments.The Vela SNR, indeed, exhibits multiple ejecta fragments, commonly referred to as shrapnel, extending beyond the forward shock. Recent investigations have identified elevated silicon (Si) abundance in two specific shrapnel, denoted as A and G, positioned in opposite directions relative to the SNR center.This observation hints at the potential presence of a Si-rich jet-counterjet structure.To address this issue I conduct an analysis of an XMM-Newton observation focused on a luminous clump situated behind shrapnel G, which aligns with the trajectory connecting shrapnel A and G, with the aim to scrutinize its physical and chemical properties, determining its association with the supposed jet-like structure. I identify two distinct structures, each exhibiting different physical characteristics. The first structure displays a remarkable elongation along the axis connecting shrapnel A and G.Despite its X-ray spectrum being considerably softer than that of the other two shrapnel, hindering Si abundance determination, its physical and chemical properties are found to be consistent with those of shrapnel A and G.The second structure exhibits a higher temperature and resembles a thin filament. Thanks to the analysis of archived ROSAT data, I find that this filament is part of an extensive and cohesive structure identified in the western rim of the shell.This feature is interpreted as a signature of a prior interaction between the remnant and the stellar wind from its progenitor star.The peculiar Ne/O ratio identified in the wind residual raises the possibility of a Wolf-Rayet progenitor for the Vela SNR. As for the case of SN 1987A, my research consists in evaluating the efficacy of the newly launched XRISM-Resolve high-resolution spectrometer in discerning distinctive signatures associated with shocked ejecta in SN 1987A.This celestial object presents a unique opportunity to scrutinize the transformation of a SN into a nascent SNR.Historically, the dominant source of X-ray emission has been the shocked CSM, with no conclusive identification of shocked ejecta. However, recent investigations provide compelling indications that the future X-ray emissions from SN 1987A will increasingly originate from the ejecta.Leveraging a state-of-the-art, self-consistent MHD simulation that intricately depicts the evolutionary stages from SN 1987A to its remnant, I generated a synthetic XRISM-Resolve spectrum for SN 1987A performance verification phase observation anticipated in 2024.My predictions distinctly highlight the prominent role of shocked ejecta in shaping the emission line profiles.Doppler broadening, resulting from the bulk motion along the line of sight of the rapidly expanding ejecta, is demonstrated to significantly increase the line widths beyond previously observed values. The quantitative comparison between my synthetic spectra and the actual XRISM spectra will provide a robust diagnostic for establishing a direct correlation between the broadened line emission and the newly shocked ejecta. This correlation, in turn, will facilitate the retrieval of essential information regarding the dynamics and chemical composition of the ejecta from the X-ray emission

    The new chamber building of Malta: architectural image and building technology

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    The knowledge of the most innovative technologies is a basic tool for all the protagonists of the building process. This is because the right resolution of the details is the main way to obtain an architectonic image that is correctly related to the design intents. This work would like to contribute to the spread of the expertise, through the choice of an interesting case study: the new Chamber Building of the Republic of Malta. The history of construction has in the evolution of the stone technology one of the most complex and interesting matter, since the Roman age. The last chapter is probably written in the new Chamber Building of the Republic of Malta, that is going to be finished in the next few months. The concept of the stone façade is founded on two main points, the formal image and the functionality. The article is addressed to the designers, construction managers and researchers who would like to have an approach to the most innovative building technologies

    Effect of hole-shape irregularities on photonic crystal waveguides

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    The effect of irregular hole shape on the spectrum and radiation losses of a photonic crystal waveguide is studied using Bloch-mode expansion. Deviations from a perfectly circular hole are characterized by a radius fluctuation amplitude and correlation angle. It is found that the parameter which determines the magnitude of the effect of disorder is the standard deviation of the hole areas. Hence, for a fixed amplitude of the radius fluctuation around the hole, those effects are strongly dependent on the correlation angle of the irregular shape. This result suggests routes to potentially improve the quality of photonic crystal structures.Comment: 3 pages, 3 figure

    Unraveling the Effects of Dense Medium on a Near to Bohm-Limit Acceleration in Kepler's SNR

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    The maximum energy of electrons accelerated by supernova remnants (SNR) is typically limited by radiative losses. In this scenario, the synchrotron cooling time scale is equal to the acceleration time scale. On the other hand, the low propagation speed of a shock in a dense medium is expected to result in an extended acceleration time scale, thus inducing a decrease in the maximum electron energy for a given SNR age and in the X-ray nonthermal flux. The young Kepler's SNR shows an enhanced efficiency of the acceleration process, which is close to the Bohm limit in the north of its shell, where the shock is slowed down by a dense circumstellar medium. Conversely, in the south, where no interaction with a dense medium is evident and the shock speed is high, the acceleration proceeds with a higher Bohm factor. To investigate this scenario, we studied the temporal evolution of the non-thermal emission, taking advantage of two Chandra X-ray observations of Kepler's SNR (performed in 2006 and 2014). We analyzed the spectra of different filaments both in the north and south of the shell, and measured their proper motion. We found a region with low shock velocity where we measured a significant decrease in flux from 2006 to 2014. This could be the first evidence of fading synchrotron emission in Kepler's SNR. This result suggests that under a certain threshold of shock speed the acceleration process could exit the loss-limited regime

    High-resolution anoscopy predictive modeling of anal canal cancer response after definitive chemoradiotherapy in COVID19 era

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    Purpose: To develop a predictive index model, integrating both clinical and high-resolution anoscopy (HRA) features to further personalize the decision making process in anal canal carcinoma in COVID19 era.Methods and materials: We assess HRA parameters after definitive chemoradiotherapy in patients with anal canal malignant lesions.Results: HRA features could be important to assess the effect of CRT and a risk stratification system should be introduced in clinical practice to better allocate therapeutic interventions.Conclusion: To our knowledge this is the first proposal for HRA findings in anal canal cancer after definitive CRT. We believe that a risk score can be useful to estimate the risk of treatment failure (in term of persistence disease and/or recurrence) and its clinical relevance should not to be underestimated

    Cervical cancer elimination in Italy: Current scenario and future endeavors for a value based prevention

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    BackgroundCervical Cancer (CC) is a vaccine-preventable disease, and it is treatable if diagnosed early and managed properly. However, it is the fourth most common cancer in women worldwide with about 604,127 cases and 341,831 deaths in 2020. In Italy, it represents the fifth most common cancer in women under 50 years of age with about 2,400 new cases in 2020. The CC elimination is today a global public health goal published by the World Health Organization (WHO) in 2020 and a commitment of the European Union that has included it in Europe's Beating Cancer Plan. Therefore, urgent action is needed, at international and national level, to implement value-based interventions regarding vaccination, screening and timely management of the disease. Our study aims to describe the state of the art of Human Papilloma Virus (HPV) prevention in Italy and to get a consensus on indicators for monitoring the progress toward CC elimination at national level. MethodsThe study envisaged the following activities: research and synthesis of the evidence on strategies and actions for CC elimination at regional Italian level; identification of indicators to monitor such strategies/actions; organization of a multi-stakeholder consensus to reach the agreement on main indicators to be used in Italy. ResultsAs for HPV vaccination coverage, the last Italian available data (December 31st, 2020) showed that it was way below the target (95%) with full cycle vaccination coverage ranging from 6 to 61.7% in female adolescents and from 5.4 to 55.4% in male adolescents (2008 birth cohorts). The coverage rate of CC screening is variable with a range of 61.7-89.6%. Furthermore, coverage rates due to organized screening programs (excluding out-of-pocket screening) shows a range from 20.7 to 71.8%. The mapping of the Italian Regions highlighted an important regional heterogeneity in respect to organizational/operational issue of HPV vaccination and CC screening. Indicators for monitoring CC elimination strategies have been drawn from the Australian experience and distinguished by disease outcomes, vaccination coverage, screening participation and treatment uptake. The highest consensus was reached for the following indicators: CC incidence; detection of high-grade cervical disease; CC mortality; full cycle vaccination coverage; screening participation; high-grade cervical disease treatment rates; CC treatment rates. ConclusionsThe assessment of the current status of CC elimination as overarching goal beyond the achievement of vaccine, screening and treatment targets represents the first step for the identification of interventions to be implemented to accelerate the path toward CC elimination. Based on this and following the WHO call, a value-based approach is proposed to untangle the full benefit of HPV-related cancers elimination strategies and identify priority and best practices

    Rainfall Field Reconstruction by Opportunistic Use of the Rain-Induced Attenuation on Microwave Satellite Signals: The July 2021 Extreme Rain Event in Germany as a Case Study

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    This paper presents a practical application of an opportunistic technique for the estimation of rainfall intensity and accumulated precipitation. The proposed technique is based upon signal strength measurements made by commercial-grade interactive satellite terminals. By applying some processing, the rain-induced attenuation on the microwave downlink from the satellite is first evaluated; then the rain attenuation is eventually mapped into a rainfall rate estimate via a tropospheric model. This methodology has been applied to a test area of 30×30 km2 around the city of Dortmund (North Rhine-Westphalia, upper basin of Ermscher river), for the heavy rain event that devastated western Germany in July, 2021. A rainfall map on this area is obtained from the measurements collected by a set of satellite terminals deployed in the region, and successfully compared with a map obtained with a conventional weather radar

    A Simultaneous Equation Model of Globalization, Corruption, Democracy, Human Development and Social Progress

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    This study builds a simultaneous equation model that establishes inter-connections among the measures of globalization, measures of democracy, human development, corruption perception index and per capita income, which in turn jointly influence social progress. The model has eleven equations in which the response variables and the predictor variables are log-linearly related. The empirical data used for estimation of the model pertain to the period 2006-2016 for 116 countries distributed over all the continents. The model has been estimated by the conventional Two-Stage Least Squares (2-SLS) and alternatively by a modified 2-SLS in which, at the second stage, Shapley value regression has been used to ameliorate the detrimental effects of collinearity among the predictor variables. It has been found that the modified 2-SLS outperforms the conventional 2-SLS. Empirically, it has been established that globalization, democracy, human development and low level of corruption are reinforcing each other and they together explain social progress quite well

    High Risk of Secondary Infections Following Thrombotic Complications in Patients With COVID-19

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    Background. This study’s primary aim was to evaluate the impact of thrombotic complications on the development of secondary infections. The secondary aim was to compare the etiology of secondary infections in patients with and without thrombotic complications. Methods. This was a cohort study (NCT04318366) of coronavirus disease 2019 (COVID-19) patients hospitalized at IRCCS San Raffaele Hospital between February 25 and June 30, 2020. Incidence rates (IRs) were calculated by univariable Poisson regression as the number of cases per 1000 person-days of follow-up (PDFU) with 95% confidence intervals. The cumulative incidence functions of secondary infections according to thrombotic complications were compared with Gray’s method accounting for competing risk of death. A multivariable Fine-Gray model was applied to assess factors associated with risk of secondary infections. Results. Overall, 109/904 patients had 176 secondary infections (IR, 10.0; 95% CI, 8.8–11.5; per 1000-PDFU). The IRs of secondary infections among patients with or without thrombotic complications were 15.0 (95% CI, 10.7–21.0) and 9.3 (95% CI, 7.9–11.0) per 1000-PDFU, respectively (P = .017). At multivariable analysis, thrombotic complications were associated with the development of secondary infections (subdistribution hazard ratio, 1.788; 95% CI, 1.018–3.140; P = .043). The etiology of secondary infections was similar in patients with and without thrombotic complications. Conclusions. In patients with COVID-19, thrombotic complications were associated with a high risk of secondary infections
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