Chi ha paura del potere? Politica e comunicazione negli studi sull’età moderna

Il saggio si propone di spiegare come la recente storiografia ha analizzato il rapporto fra potere e comunicazione nel corso dell’età moderna. Le ricerche svolte hanno avuto il merito di saldare molteplici frameworks metodologici (quelli della storia culturale, intellettuale, istituzionale, politica, ed economica), riuscendo così a ricostruire fitte reti di connessione tra diversi luoghi lontani e rilevando la presenza di un sistema globale già a partire dal XVI secolo. Tuttavia i modelli interpretativi correnti non paiono ancora sufficienti a disvelare la fabbrica dell’informazione. Quello che manca è una focalizzazione sulle forze sociali, politiche ed economiche che plasmano l’informazione e veicolano i flussi comunicativi. È quindi necessario – sottolineano gli autori – affinare gli strumenti di indagine per identificare chi costruisce le notizie e quali poteri esercitano la loro egemonia sull’infosfera.The essay aims to explain how recent historiography has analyzed the relationship between power and communication in the early modern age. The research carried out had the merit of welding multiple methodological frameworks (those of cultural, intellectual, institutional, political, and economic history), thus succeeding in reconstructing dense networks of connection among different distant places and detecting the presence of a global system since the beginning of the 16th century. However, current interpretative models still do not seem sufficient to unveil the information factory. What is missing is a deeper focus on the social, political, and economic forces that shape information and convey communication flows. It is therefore necessary – the authors argue – to refine the investigation tools to identify who builds the news and which powers exercise their hegemony over the infospher

Chi ha paura del potere? Politica e comunicazione negli studi sull'età moderna

This essay aims to explain how recent historiography has analysed the relationship between power and communication in the early modern age. The research that was carried out had the merit of fusing together multiple methodological frameworks (those of cultural, intellectual, institutional, political, and economic history), thus succeeding in reconstructing dense networks of linkage among different, distant places and finding the presence of a global system since the beginning of the 16th century. However, current interpretative models do not yet seem sufficient to unveil the information factory. What is missing is a deeper focus on the social, political, and economic forces that shape information and convey communication flows. It is therefore necessary – the authors argue – to refine the investigation tools to identify who builds the news and which powers exercise their hegemony over the infosphere

Optimization of the energy for Breast monochromatic absorption X-ray Computed Tomography

The limits of mammography have led to an increasing interest on possible alternatives such as the breast Computed Tomography (bCT). The common goal of all X-ray imaging techniques is to achieve the optimal contrast resolution, measured through the Contrast to Noise Ratio (CNR), while minimizing the radiological risks, quantified by the dose. Both dose and CNR depend on the energy and the intensity of the X-rays employed for the specific imaging technique. Some attempts to determine an optimal energy for bCT have suggested the range 22keV\u201334keV, some others instead suggested the range 50keV\u201360keV depending on the parameters considered in the study. Recent experimental works, based on the use of monochromatic radiation and breast specimens, show that energies around 32keV give better image quality respect to setups based on higher energies. In this paper we report a systematic study aiming at defining the range of energies that maximizes the CNR at fixed dose in bCT. The study evaluates several compositions and diameters of the breast and includes various reconstruction algorithms as well as different dose levels. The results show that a good compromise between CNR and dose is obtained using energies around 28keV

Imaging spectroscopic performances for a Si based detection system

We present the imaging and spectroscopic capabilities of a system based on a single photon counting chip (PCC) bump-bonded on a Si pixel detector. The system measures the energy spectrum and the flux, produced by a standard mammographic tube. We have also made some images of low contrast details, achieving good results

Vox clamantis in deserto: a survey among Italian psychiatrists on defensive medicine and professional liability

Due to recent events, professional liability for psychiatrists in Italy is currently a matter of lively debate. Specifically, overwhelming pressure on psychiatrists’ duties has been brought by regulatory developments, such as the closure of forensic psychiatric hospitals, with the consequent return of offenders to community-based care, and the mental health consequences of the pandemic. According to Italian courts, psychiatrists are not only responsible for diagnostic and therapeutic appropriateness but also for the effects of their interventions on patients, and their behaviors. The aim of this study was to explore the attitude and behaviors of Italian psychiatrists regarding defensive medicine and professional liability. A total sample of 254 psychiatrists was surveyed by means of a quantitative online questionnaire. Most psychiatrists reported practicing defensive medicine (no. 153/254, 60.2%) and felt that their position of guarantee compromised their work in healthcare for patients (no. 138/253, 54.3%). Age correlated inversely with acknowledgment of defensive practices (r = −0.245, p < 0.001), with younger physicians more prone to defensive medicine (p = 0.013), particularly for patients at risk of suicide or violence. Psychiatrists in ‘closed’ settings (hospital wards, residential and rehabilitation centers, mental health service units in prison) reported more malpractice claims (p = 0.037) and complaints (p = 0.031), as well as a greater propensity to act defensively. In the treatment of patients with violent behavior, suicidal ideation, dual diagnoses, and criminal convictions, defensive practices were associated more with perceived legal risks (r = 0.306, p < 0.001) than actual legal involvement (p > 0.05). Anxiety, anger, and restlessness were common reactions to legal complaints, involving no. 50/254 (19.7%) respondents, with 40% reporting impaired functioning. Most psychiatrists (no. 175/253, 68.9%) were concerned about both civil and criminal laws regarding their professional responsibility, but many were not fully informed about recent legislative regulations and younger physicians resulted scarcely trained in risk management (p < 0.001). In conclusion, our findings suggest that defensive medicine is a common phenomenon among psychiatrists and their position of guarantee drives this attitude. Education on legal implications and risk management should be provided starting from the university and continuing over time, to improve the knowledge of young and senior doctors on professional liability and inform their decision-making processes. This would also reduce defensive practices and improve the quality of healthcare. Considering the concerns of younger physicians, as well as of professionals working in acute and high-intensity medical care facilities, there is also an urgent need for a revision of the medical liability to ensure the sustainability of the National Health Service

Phase-contrast breast CT: the effect of propagation distance

X-ray phase imaging has the potential to dramatically improve soft tissue contrast sensitivity, which is a crucial requirement in many diagnostic applications such as breast imaging. In this context, a program devoted to perform in-vivo phase-contrast synchrotron radiation breast computed tomography is ongoing at the Elettra facility (Trieste, Italy). The used phase-contrast technique is the propagation-based configuration, which requires a spatially coherent source and a sufficient object-to-detector distance. In this work the effect of this distance on image quality is quantitatively investigated scanning a large breast surgical specimen at 3 object-to-detector distances (1.6, 3, 9 m) and comparing the images both before and after applying the phase-retrieval procedure. The sample is imaged at 30 keV with a 60 \ub5m pixel pitch CdTe single-photon-counting detector, positioned at a fixed distance of 31.6~m from the source. The detector fluence is kept constant for all acquisitions. The study shows that, at the largest distance, a 20-fold SNR increase can be obtained by applying the phase-retrieval procedure. Moreover, it is shown that, for phase-retrieved images, changing the object-to-detector distance does not affect spatial resolution while boosting SNR (4-fold increase going from the shortest to the largest distance). The experimental results are supported by a theoretical model proposed by other authors, whose salient results are presented in this paper

Semiconductor pixel detectors for digital mammography

Abstract We present some results obtained with silicon and gallium arsenide pixel detectors to be applied in the field of digital mammography. Even though GaAs is suitable for medical imaging applications thanks to its atomic number, which allows a very good detection efficiency, it often contains an high concentrations of traps which decrease the charge collection efficiency (CCE). So we have analysed both electrical and spectroscopic performance of different SI GaAs diodes as a function of concentrations of dopants in the substrate, in order to find a material by which we can obtain a CCE allowing the detection of all the photons that interact in the detector. Nevertheless to be able to detect low contrast details, efficiency and CCE are not the only parameters to be optimized; also the stability of the detection system is fundamental. In the past we have worked with Si pixel detectors; even if its atomic number does not allow a good detection efficiency at standard thickness, it has a very high stability. So keeping in mind the need to increase the Silicon detection efficiency we performed simulations to study the behaviour of the electrical potential in order to find a geometry to avoid the risk of electrical breakdown

Experimental study of Compton scattering reduction in digital mammographic imaging

In mammography, the first cause of image contrast reduction arises from the photons scattered inside the examined organ. The amount of Compton scattering strongly depends on the irradiation area and on the distance between the organ and the X-ray detector. We have experimentally evaluated how these geometrical conditions affect the scattering fraction. Our experimental setup includes a single photon counting device based on a silicon pixel detector as X-ray sensor; a lucite cylinder to simulate the breast tissue, and a lead collimator to define the irradiation area. We have evaluated the contrast and the signal-to-noise ratio for images acquired in different conditions

Experimental study of Compton scattering reduction in digital mammographic imaging

In mammography, the first cause of image contrast reduction arises from the photons scattered inside the examined organ. The amount of Compton scattering strongly depends on the irradiation area and on the distance between the organ and the X-ray detector. We have experimentally evaluated how these geometrical conditions affect the scattering fraction. Our experimental setup includes a single photon counting device based on a silicon pixel detector as X-ray sensor; a lucite cylinder to simulate the breast tissue, and a lead collimator to define the irradiation area. We have evaluated the contrast and the signal-to-noise ratio for images acquired in different conditions

Study of GaAs detectors characteristics for medical imaging

In this work we present the results of a systematic study about SI GaAs detectors as a function of substrate and contact type, geometry and thickness. This study has been stimulated from the interest in using GaAs as a detector for medical imaging applications. GaAs detectors have been produced using crystals grown with different techniques and changing both the thickness (in the range 200 μm-1 mm) and the contacts type and geometry. We have measured the current-voltage characteristics and, using radioactive sources (109Cd, 20 keV photons, 241Am, 60 keV photons, 99mTc, 140 keV photons), we have studied the performance of our detectors in terms of charge collection efficiency and energy resolution as a function of the bias voltage. Besides we have also studied the electrical and spectroscopic properties of GaAs detectors with different types and concentrations of the dopants in the substrate. So we have found the optimal doping type and concentration to have the best spectroscopic performances and the higher breakdown voltage. Simulation programs made with Monte Carlo methods have been developed to describe the electric field distribution and the transport of charge carriers toward the electrodes in GaAs detectors. In these simulations we have considered the presence of deep energy levels in the bandgap, the thickness, the bias voltage and the charge deposition in the crystal after photon interaction