Probing dissipation mechanisms in BL Lac jets through X-ray polarimetry

The dissipation of energy flux in blazar jets plays a key role in the acceleration of relativistic particles. Two possibilities are commonly considered for the dissipation processes, magnetic reconnection -- possibly triggered by instabilities in magnetically-dominated jets -- , or shocks -- for weakly magnetized flows. We consider the polarimetric features expected for the two scenarios analyzing the results of state-of-the-art simulations. For the magnetic reconnection scenario we conclude, using results from global relativistic MHD simulations, that the emission likely occurs in turbulent regions with unstructured magnetic fields, although the simulations do not allow us to draw firm conclusions. On the other hand, with local particle-in-cell simulations we show that, for shocks with a magnetic field geometry suitable for particle acceleration, the self-generated magnetic field at the shock front is predominantly orthogonal to the shock normal and becomes quasi-parallel downstream. Based on this result we develop a simplified model to calculate the frequency-dependent degree of polarization, assuming that high-energy particles are injected at the shock and cool downstream. We apply our results to HBLs, blazars with the maximum of their synchrotron output at UV-soft X-ray energies. While in the optical band the predicted degree of polarization is low, in the X-ray emission it can ideally reach 50\%, especially during active/flaring states. The comparison between measurements in the optical and in the X-ray band made during active states (feasible with the planned {\it IXPE} satellite) are expected to provide valuable constraints on the dissipation and acceleration processes.Comment: 9 pages, 6 figures, accepted for publication by MNRA

Coffee as a nutraceutical beverage

In a recent paper we found that coffee consumption was associated with a decreased risk of developing asymptomatic PAD in a selected population of pre-menopausal women (Mattioli, Migaldi, & Farinetti, 2018). Women with high coffee consumption had a good adherence to Mediterranean Diet and high levels of physical activity suggesting a healthier lifestyle, a known factor of prevention of atherosclerosis

Leveraging mechanobiology and biophysical cues in lung organoids for studying lung development and disease

Lung organoids have emerged as powerful tools for studying lung distal diseases by recapitulating the cellular diversity and microenvironment of the lung tissue. This review article highlights the advancements in leveraging mechanobiology and biophysical cues in lung organoid engineering to improve their physiological relevance and disease modelling capabilities. We discuss the role of mechanobiology in lung development and homeostasis, as well as the integration of biophysical cues in the design and culture of lung organoids. Furthermore, we explore how these advancements have contributed to the understanding of lung distal diseases pathogenesis. We also discuss the challenges and future directions in harnessing mechanobiology and biophysical cues in lung organoid research. This review showcases the potential of lung organoids as a platform to investigate the underappreciated impacts of biophysical and biomechanical properties in enhancing lung organoids complexity and functionality, and ultimately provide new insight into embryonic lung development and pulmonary distal diseases pathogenesis

Fruit and vegetables in hypertensive women with asymptomatic peripheral arterial disease

Background and aims: Fruit and vegetables are considered a very healthy diet useful in the prevention of cardiovascular disease. The present study aims to evaluate intake of fruit and vegetables in hypertensive women and its correlation with asymptomatic atherosclerosis. Methods and results: A group of 237 women with hypertension was evaluated. Fruit and vegetables consumption were assessed by a self-administered food frequency validated questionnaire completed by an interviewer administered 24 h diet recall. They all underwent ABI. ABI measurement observed that fruit consumption was inversely associated with pre-clinical atherosclerosis suggesting a protective effect, moreover this association was stronger for vegetables. Increasing intake of vegetables was associated with a lower risk of asymptomatic PAD. Conclusions: Women with a high intake of fruit and vegetables showed less instrumental sign of preclinical peripheral atherosclerosis. Can be suggests that fruit and vegetables play an important role in prevention of atherosclerosis in pre-menopausal women

Probing shock acceleration in BL Lac jets through X-ray polarimetry: the time-dependent view

Polarimetric measurements, especially if extended at high energy, are expected to provide important insights into the mechanisms underlying the acceleration of relativistic particles in jets. In a previous work we have shown that the polarization of the synchrotron X-ray emission produced by highly energetic electrons accelerated by a mildly relativistic shock carries essential imprints of the geometry and the structure of the magnetic fields in the downstream region. Here we present the extension of our analysis to the non-stationary case, especially suitable to model the highly variable emission of high-energy emitting BL Lacs. We anticipate a large ($\Pi \approx 40\%$), almost time-independent degree of polarization in the hard/medium X-ray band, a prediction soon testable with the upcoming mission {\it IXPE}. The situation in other bands, in particular in the optical, is more complex. A monotonic decrease of the optical degree of polarization is observed during the development of a flare. At later stages $\Pi$ reaches zero and then it starts to increase, recovering large values at late times. The instant at which $\Pi=0$ is marked by a rotation of the polarization angle by $90$ degrees. However, at optical frequencies it is likely that more than one region contributes to the observed emission, potentially making it difficult to detect the predicted behavior.Comment: 11 pages, 9 figures, accepted for publication by MNRA

Physical activity in premenopausal women with asymptomatic peripheral arterial disease

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