ULTRALIGHT RADAR FOR SMALL AND MICRO-UAV NAVIGATION

This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV) in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed approach comprises one multi-rotor UAV and one ultralight commercial radar. Results from flight tests in which both forward-only motion and mixed motion are presented and analysed, providing a reference for understanding outputs of radar in complex scenarios. The radar odometry solution is compared with ground truth provided by GPS sensor

ULTRALIGHT RADAR FOR SMALL AND MICRO-UAV NAVIGATION

This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV) in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed approach comprises one multi-rotor UAV and one ultralight commercial radar. Results from flight tests in which both forward-only motion and mixed motion are presented and analysed, providing a reference for understanding outputs of radar in complex scenarios. The radar odometry solution is compared with ground truth provided by GPS sensor

The impact of Covid-19 healthcare emergency on the psychological well-being of health professionals: a review of literature

Introduction. The Coronavirus pandemic (Covid-19) was first identified in December 2019 in the city of Wuhan, China, and later caused a severe health crisis, causing massive disruptions to most healthcare systems worldwide. The Covid-19 health emergency has seen healthcare workers in the front line facing all the difficulties related to the care burden. One of the most significant and probably underinvestigated aspects is the psychological stress of the healthcare staff managing the emergency. The aim of the paper is to analyze the literature on the impact of the Covid-19 crisis on the psychological well-being of health professionals.Methodology. We conducted a systematic review of articles published on this topic during the months from January 2020 to December 2020, searching on Pub Med, Scopus and Web of Science databases.Results. Most of the issues can be summarized into five conceptual categories: Stress, Depression and Infection Anxiety, Anguish, Insomnia, Post Traumatic Stress Disorder, and Suicide. The literature identifies many factors contributing to the onset of anxiety, depression, and stress, like the fear of contracting the disease and transmitting it to family members and friends, stressful shifts, and little rest among several others. The literature highlights the needs for adequate measures, including proper psychological support.Conclusion. The conducted review suggests that the behaviours of healthcare professionals during the emergency phase of the Covid-19 pandemic show psychological disorders that can compromise mental health. Therefore, there is a call for those in chief like hospital managers and policymakers to take action, promoting measures like surveillance, monitoring, and psychological support among others, to increase the resilience of healthcare workers, limiting stress and anxiety and allowing them to keep their performance at work

The impact of Covid-19 healthcare emergency on the psychological well-being of health professionals: a review of literature

Introduction. The Coronavirus pandemic (Covid-19) was first identified in December 2019 in the city of Wuhan, China, and later caused a severe health crisis, causing massive disruptions to most healthcare systems worldwide. The Covid-19 health emergency has seen healthcare workers in the front line facing all the difficulties related to the care burden. One of the most significant and probably underinvestigated aspects is the psychological stress of the healthcare staff managing the emergency. The aim of the paper is to analyze the literature on the impact of the Covid-19 crisis on the psychological well-being of health professionals. Methodology. We conducted a systematic review of articles published on this topic during the months from January 2020 to December 2020, searching on Pub Med, Scopus and Web of Science databases. Results. Most of the issues can be summarized into five conceptual categories: Stress, Depression and Infection Anxiety, Anguish, Insomnia, Post Traumatic Stress Disorder, and Suicide. The literature identifies many factors contributing to the onset of anxiety, depression, and stress, like the fear of contracting the disease and transmitting it to family members and friends, stressful shifts, and little rest among several others. The literature highlights the needs for adequate measures, including proper psychological support. Conclusion. The conducted review suggests that the behaviours of healthcare professionals during the emergency phase of the Covid-19 pandemic show psychological disorders that can compromise mental health. Therefore, there is a call for those in chief like hospital managers and policymakers to take action, promoting measures like surveillance, monitoring, and psychological support among others, to increase the resilience of healthcare workers, limiting stress and anxiety and allowing them to keep their performance at work

Periodontal effects of the reversible dipeptidyl peptidase 1 inhibitor brensocatib in bronchiectasis

Aims: Brensocatib is a reversible inhibitor of dipeptidyl peptidase 1 (cathepsin C), in development to treat chronic non-cystic fibrosis bronchiectasis. The phase 2, randomized, placebo-controlled WILLOW trial (NCT03218917) was conducted to examine whether brensocatib reduced the incidence of pulmonary exacerbations. Brensocatib prolonged the time to the first exacerbation and led to fewer exacerbations than placebo. Because brensocatib potentially affects oral tissues due to its action on neutrophil-mediated inflammation, we analyzed periodontal outcomes in the trial participants.Materials and Methods: Patients with bronchiectasis were randomized 1:1:1 to receive once-daily oral brensocatib 10 or 25 mg or placebo. Periodontal status was monitored throughout the 24-week trial in a prespecified safety analysis. Periodontal pocket depth (PPD) at screening, week 8, and week 24 was evaluated. Gingival inflammation was evaluated by a combination of assessing bleeding upon probing and monitoring the Löe-Silness Gingival Index on 3 facial surfaces and the mid-lingual surface.Results: At week 24, mean ± SE PPD reductions were similar across treatment groups: -0.07 ± 0.007, -0.06 ± 0.007, and -0.15 ± 0.007 mm with brensocatib 10 mg, brensocatib 25 mg, and placebo, respectively. The distribution of changes in PPD and the number of patients with multiple increased PPD sites were similar across treatment groups at weeks 8 and 24. The frequencies of gingival index values were generally similar across treatment groups at each assessment. An increase in index values 0-1 and a decrease in index values 2-3 over time and at the end of the study were observed in all groups, indicating improved oral health.Conclusions: In patients with non-cystic fibrosis bronchiectasis, brensocatib 10 or 25 mg had an acceptable safety profile after 6 months' treatment, with no changes in periodontal status noted. Improvement in oral health at end of the study may be due to regular dental care during the trial and independent of brensocatib treatment.Knowledge Transfer Statement: The results of this study suggest that 24 weeks of treatment with brensocatib does not affect periodontal disease progression. This information can be used by clinicians when considering treatment approaches for bronchiectasis and suggests that the use of brensocatib will not be limited by periodontal disease risks. Nevertheless, routine dental/periodontal care should be provided to patients irrespective of brensocatib treatment.</p

The effect of minihaloes on cosmic reionization

One of the most debated issues in the theoretical modeling of cosmic reionization is the impact of small-mass gravitationally-bound structures. We carry out the first numerical investigation of the role of such sterile `minihaloes', which serve as self-shielding screens of ionizing photons. Minihaloes are too small to be properly resolved in current large-scale cosmological simulations, and thus we estimate their effects using a sub-grid model, considering two cases that bracket their effect within this framework. In the `extreme suppression' case in which minihalo formation ceases once a region is partially ionized, their effect on cosmic reionization is modest, reducing the volume-averaged ionization fraction by an overall factor of less than 15%. In the other extreme, in which minihalo formation is never suppressed, they delay complete reionization as much as Delta z~2, in rough agreement with the results from a previous semi-analytical study by the authors. Thus, depending on the details of the minihalo formation process, their effect on the overall progress of reionization can range from modest to significant, but the minihalo photon consumption is by itself insufficient to force an extended reionization epoch.Comment: 9 pages, 2 figures, accepted for pubblication in MNRA

Quasars: What turns them off?

(Abridged) We explore the idea that the anti-hierarchical turn-off observed in the quasar population arises from self-regulating feedback, via an outflow mechanism. Using a detailed hydrodynamic simulation we calculate the luminosity function of quasars down to a redshift of z=1 in a large, cosmologically representative volume. Outflows are included explicitly by tracking halo mergers and driving shocks into the surrounding intergalactic medium. Our results are in excellent agreement with measurements of the spatial distribution of quasars, and we detect an intriguing excess of galaxy-quasar pairs at very short separations. We also reproduce the anti-hierarchical turnoff in the quasar luminosity function, however, the magnitude of the turn-off falls short of that observed as well as that predicted by analogous semi-analytic models. The difference can be traced to the treatment of gas heating within galaxies. The simulated galaxy cluster L_X-T relationship is close to that observed for z~1 clusters, but the simulated galaxy groups at z=1 are significantly perturbed by quasar outflows, suggesting that measurements of X-ray emission in high-redshift groups could well be a "smoking gun" for the AGN heating hypothesis.Comment: 16 pages, 11 figures, submitted to ApJ, comments welcome

Space-oriented navigation solutions with integrated sensor-suite: the I3DS H2020 project

In all orbital applications, such as on-orbit servicing and repair, rendezvous and docking, active debrisremoval (ADR), and planetary applications, such as exploration of unknown environments for scientificpurposes by means of rovers, GPS-denied navigation aspects have a very large impact on the successfuloutcome of missions. Having a sensor suite, and hence several different sensors, also requires, at the sametime, a suite of navigation algorithms able to deal with different kinds of inputs. Some of them, however,can be shared between multiple sensors, after thorough pre-processing of the raw data. Additionally, thesame kind of sensor can require two different navigation algorithms depending on the scenario. The workdescribed in this paper aims to present and critically discuss the approach to precise relative navigationsolutions with a complete suite of sensors and their performance in different space-oriented applicationscenarios.Standalone navigation filters are examined. In the case of a high-resolution camera for an orbitalscenario, the pose of a target, with respect to a chaser, can be thoroughly obtained with the aid offiducial markers. Stereo camera-based navigation is also addressed with visual odometry. In the case of astereo camera the problem of scale estimation during odometry is solved by means of triangulation. Sincethe outputs of the sensor-suite are also dense 3D point clouds, Iterative Closest Point and Histogram ofDistances (HoD) with Kalman filter approaches are analyzed, paying attention to the provision of correctsensor characterization. The results for each filter are exhaustively examined, highlighting their strengthsand the points where some improvements can be achieve

Double-detonation sub-Chandrasekhar supernovae: synthetic observables for minimum helium shell mass models

Abridged. In the double detonation scenario for Type Ia supernovae (SNe Ia) a detonation initiates in a shell of He-rich material accreted from a companion star by a sub-Chandrasekhar-mass White Dwarf (WD). This shell detonation drives a shock front into the carbon-oxygen (C/O) WD that triggers a secondary detonation in the core. The core detonation results in a complete disruption of the WD. Earlier studies concluded that this scenario has difficulties in accounting for the observed properties of SNe Ia since the explosion ejecta are surrounded by the products of explosive He burning in the shell. Recently, it was proposed that detonations might be possible for much less massive He shells than previously assumed. Moreover, it was shown that even detonations of these minimum He shell masses robustly trigger detonations of the C/O core. Here we present time-dependent multi-wavelength radiative transfer calculations for models with minimum He shell mass and derive synthetic observables for both the optical and {\gamma}-ray spectral regions. These differ strongly from those found in earlier simulations of sub-Chandrasekhar-mass explosions in which more massive He shells were considered. Our models predict light curves which cover both the range of brightnesses and the rise and decline times of observed SNe Ia. However, their colours and spectra do not match the observations. In particular, their B-V colours are generally too red. We show that this discrepancy is mainly due to the composition of the burning products of the He shell of our models which contain significant amounts of Ti and Cr. Using a toy model, we also show that the burning products of the He shell depend crucially on its initial composition. This leads us to conclude that good agreement between sub-Chandrasekhar-mass explosions and observed SNe Ia may still be feasible but further study of the shell properties is required.Comment: 17 pages, 13 figures. Accepted for publication by Ap

Lensing-Induced Structure of Submillimeter Sources: Implications for the Microwave Background

We consider the effect of lensing by galaxy clusters on the angular distribution of submillimeter wavelength objects. While lensing does not change the total flux and number counts of submillimeter sources, it can affect the number counts and fluxes of flux-limited samples. Therefore imposing a flux cut on point sources not only reduces the overall Poisson noise, but imprints the correlations between lensing clusters on the unresolved flux distribution. Using a simple model, we quantify the lensing anisotropy induced in flux-limited samples and compare this to Poisson noise. We find that while the level of induced anisotropies on the scale of the cluster angular correlation length is comparable to Poisson noise for a slowly evolving cluster model, it is negligible for more realistic models of cluster evolution. Thus the removal of point sources is not expected to induce measurable structure in the microwave or far-infrared backgrounds.Comment: 22 pages, 9 figures, accepted to Astrophysical Journa