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Two-dimensional leaky-wave antennas (LWAs) are a class of planar, traveling-wave radiators with attractive features of a low profile, ease of feeding, frequency reconfigurability of the radiation pattern, and polarization agility. Their use in conjunction with array feeders has been the subject of various investigations in recent decades, thanks to the additional degrees of freedom provided by the presence of multiple independent sources. Here, we provide a review of some of the most recent and promising array-fed two-dimensional (2-D) LWAs, selecting a couple of the most significant structures in application, namely Fabry–Perot cavity antennas and bull's-eye antennas, and discussing some of their recently proposed advanced features. [ABSTRACT FROM AUTHOR]

In a software-defined radar (SDR) system, most of the signal processing usually implemented in hardware is implemented by software, thus allowing for higher flexibility and modularity compared to conventional radar systems. However, the majority of SDR demonstrators and proofs of concept reported in the open literature so far have been based on simple antenna systems. As a result, the full potentialities of an SDR approach have not been completely exploited yet. In this work, we propose a flexible antenna module to be integrated into an active electronically scanning array (AESA) with controlled sidelobe level over a wide angular range, exhibiting polarization reconfigurability with a low cross-polarization level and high isolation. For this purpose, analytical and numerically efficient techniques for the synthesis of the aperture distribution and the correct evaluation of the radiating features (e.g., beamwidth, pointing angle, sidelobe levels, etc.) are presented in order to grant real-time control of the digital beamforming network. A sub-array module demonstrator is fabricated and measured to corroborate the concept. [ABSTRACT FROM AUTHOR]

Background: The post‐operative course after Liver Transplantation (LT) can be complicated by early allograft dysfunction (EAD), primary nonfunction (PNF) and death. A lactate concentration at the end of transplant of ≥5 mmol/L was recently proposed as a predictive marker of PNF, EAD, and mortality; this study aimed to validate these previous reports in a large single center cohort. Methods: This retrospective cohort study included adult liver transplant recipients who received grafts from deceased donors at our center between June 2012 and May 2021. Receiver operating characteristic (ROC) curves for the lactate concentration at the end of transplantation were computed to determine the AUC for PNF, EAD and mortality at 90 days. Results: In our cohort of 1137 cases, the AUCs for lactate to predict EAD, PNF and mortality were respectively.56 (95% confidence interval [CI]:.53–.60),.69 (95% CI:.52–.85), and.74 (95% CI:.63–.84). Conclusion: The clinical value of lactate concentration at the end of transplantation to predict PNF, EAD and mortality at 90 days was, at best, modest, as shown by the relatively low AUCs. Our findings cannot validate previous reports that the lactate level alone is a good predictor of poor outcomes after liver transplantation. [ABSTRACT FROM AUTHOR]

Food systems are responsible for a large share of anthropogenic impacts. In recent debates, the need to strengthen the link between science and policy has emerged with the proposal to establish a new global science–policy interface for a sustainable food system. While the clash between those who consider necessary and those who do not consider necessary the creation of this panel increases, this paper takes inspiration from this debate to highlight how strengthening the interactions between science and policy should be supported by increasing the informativeness of current sustainability assessments, regardless of the need for such a panel. In particular, we delve into this emerging topic by focusing on some critical aspects of the current sustainability assessments of food systems, which include the need for more comprehensive assessments, based on the joint use of multiple indicators. While sustainability assessments of food systems have been historically focusing on just one–two externalities at a time, the introduction of new multi-faceted indicators make it now possible to look at multiple externalities concurrently and at the trade-offs among them. Dietary contextualization becomes essential too, to avoid the provision of misleading information. An operative framework to improve sustainability assessments of food systems is presented here and discussed with the aim of promoting more informative approaches, which are crucial for transforming scientific knowledge into mitigation policies. [ABSTRACT FROM AUTHOR]