Cosmic voids uncovered -- first-order statistics of depressions in the biased density field

Cosmic voids are the major volume component in the matter distribution of the Universe. They posses great potential for constraining dark energy as well as for testing theories of gravity. Nevertheless, in spite of their growing popularity as cosmological probes, a gap of knowledge between cosmic void observations and theory still persists. In particular, the void size function models proposed in literature have been proven unsuccessful in reproducing the results obtained from cosmological simulations in which cosmic voids are detected from biased tracers of the density field, undermining the possibility of using them as cosmological probes. The goal of this work is to cover this gap. In particular, we make use of the findings of a previous work in which we have improved the void selection procedure, presenting an algorithm that redefines the void ridges and, consequently, their radius. By applying this algorithm, we validate the volume conserving model of the void size function on a set of unbiased simulated density field tracers. We highlight the difference in the internal structure between voids selected in this way and those identified by the popular VIDE void finder. We also extend the validation of the model to the case of biased tracers. We find that a relation exists between the tracer used to sample the underlying dark matter density field and its unbiased counterpart. Moreover, we demonstrate that, as long as this relation is accounted for, the size function is a viable approach for studying cosmology with cosmic voids.Comment: 11 pages, 6 figures, 3 tables, submitted to MNRA

Cosmological exploitation of the size function of cosmic voids identified in the distribution of biased tracers

Cosmic voids are large underdense regions that, together with galaxy clusters, filaments and walls, build up the large-scale structure of the Universe. The void size function provides a powerful probe to test the cosmological framework. However, to fully exploit this statistics, the void sample has to be properly cleaned from spurious objects. Furthermore, the bias of the mass tracers used to detect these regions has to be taken into account in the size function model. In our work we test a cleaning algorithm and a new void size function model on a set of simulated dark matter halo catalogues, with different mass and redshift selections, to investigate the statistics of voids identified in a biased mass density field. We then investigate how the density field tracers' bias affects the detected size of voids. The main result of this analysis is a new model of the size function, parameterised in terms of the linear effective bias of the tracers used, which is straightforwardly inferred from the large-scale two-point correlation function. This represents a crucial step to exploit the method on real data catalogues. The proposed size function model has been accurately calibrated on mock catalogues, and used to validate the possibility to provide forecasts on the cosmological constraints, namely on the matter density contrast, $\Omega_{\rm M}$, and on the normalisation of the linear matter power spectrum, $\sigma_8$, at different redshifts.Comment: 17 pages, 11 figures, 4 tables, accepted by MNRA

Design for Cultural Heritage at the University of Ferrara

Alongside Teaching and Research, Italian universities are also committed to Public Engagement activities featuring teaching and cultural initiatives for a non-academic audience. At the University of Ferrara, this commitment was translated into an exhibition in April 2019, originating from a virtuous union of cultural heritage and teaching activities. The creation of the “Natura Naturata” exhibition involved the synthesis of taught courses and research by the University of Ferrara's Industrial Product Design students together with their teachers, in collaboration with librarians. In the Product Design 2 Workshop, students develop exhibition projects, starting from the curatorial concept, through the construction, up to the graphic-communicative aspects and the creation of information and teaching tools. The exhibition was created based on the study of rules used to properly protect library assets so that students could gain specific skills for the preparation of bibliographic exhibitions. It took shape in the Chemistry and Life Sciences Library Santa Maria delle Grazie to emphasize the importance of the University's tangible and intangible cultural heritage with the intention of conveying the 'world' of library collections – and also the University's historical and architectural heritage - to students, scholars, and citizens.Bernabè, A.; Contarini, M.; Manfra, M.; Turrini, D. (2020). Design for Cultural Heritage at the University of Ferrara. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):455-463. https://doi.org/10.4995/HEAd20.2020.11085OCS45546330-05-202

Cosmological constraints from the BOSS DR12 void size function

We present the first cosmological constraints derived from the analysis of the void size function. This work relies on the final BOSS DR12 data set, a large spectroscopic galaxy catalog, ideal for the identification of cosmic voids. We extract a sample of voids from the distribution of galaxies and we apply a cleaning procedure aimed at reaching high levels of purity and completeness. We model the void size function by means of an extension of the popular volume-conserving model, based on two additional nuisance parameters. Relying on mock catalogs specifically designed to reproduce the BOSS DR12 galaxy sample, we calibrate the extended size function model parameters and validate the methodology. We then apply a Bayesian analysis to constrain the $\Lambda$CDM model and one of its simplest extensions, featuring a constant dark energy equation of state parameter, $w$. Following a conservative approach, we put constraints on the total matter density parameter and the amplitude of density fluctuations, finding $\Omega_{\rm m}=0.29 \pm 0.06$ and $\sigma_8=0.79^{+0.09}_{-0.08}$. Testing the alternative scenario, we derive $w=-1.1\pm 0.2$, in agreement with the $\Lambda$CDM model. These results are independent and complementary to those derived from standard cosmological probes, opening up new ways to identify the origin of potential tensions in the current cosmological paradigm.Comment: 24 pages, 13 figures, 3 tables, accepted by Ap

The perspective of voids on rising cosmology tensions

We investigate the main tensions within the current standard model of cosmology from the perspective of the main statistics of cosmic voids, using the final BOSS DR12 data set. For this purpose, we present the first estimate of the $S_8\equiv \sigma_8\sqrt{\Omega_{\rm m}/0.3}$ and $H_0$ parameters obtained from void number counts and shape distortions. To analyze void counts we relied on an extension of the popular volume-conserving model for the void size function, tailored to the application on data, including geometric and dynamic distortions. We calibrated the two nuisance parameters of this model with the official BOSS collaboration mock catalogs and propagated their uncertainty through the statistical analysis of the BOSS void number counts. The constraints from void shapes come from the study of the geometric distortions of the stacked void-galaxy cross-correlation function. In this work we focus our analysis on the $\Omega_{\rm m}$-$\sigma_8$ and $\Omega_{\rm m}$-$H_0$ parameter planes and derive the marginalized constraints $S_8 = 0.813^{+0.093}_{-0.068}$ and $H_0 = 67.3^{+10.0}_{-9.1} \ \mathrm{km} \ \mathrm{s}^{-1} \ \mathrm{Mpc}^{-1}$, which are fully compatible with constraints from the literature. These results are expected to notably improve in precision when analyzed jointly with independent probes and will open a new viewing angle on the rising cosmological tensions in the near future.Comment: 8 pages, 5 figures, published in A&

Knowledge and attitudes on influenza vaccination among Italian physicians specialized in respiratory infections: an Italian Respiratory Society (SIP/IRS) web-based survey.

Not available for a letter to Edito

A Prospective, observational, Italian multi-center registry of self-aPposing® cOronary Stents in patients presenting with ST-segment Elevation Myocardial InfarcTION: The iPOSITION registry

Background: Primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) can be challenging for high thrombus burden and catecholamine-induced vasoconstriction. The Xposition-S stent was designed to prevent stent undersizing and minimize strut malapposition. We evaluated 1-year clinical outcomes of a nitinol, self-apposing®, sirolimus-eluting stent, pre-mounted on a novel balloon delivery system, in de novo lesions of patients presenting with STEMI undergoing pPCI. Methods: The iPOSITION is a prospective, multicenter, post-market, observational study. The primary endpoint, target lesion failure (TLF), was defined as the composite of cardiac death (CD), recurrent target vessel myocardial infarction (TV-MI), and clinically driven target lesion revascularization (TLR). Results: The study enrolled 247 STEMI patients from 7 Italian centers. Both device and procedural success occurred in 99.2% of patients, without any death, TV-MI, TLR, or stent thrombosis (ST) during the hospital stay and at 30-day follow-up. At 1 year, TLF occurred in 2.6%, CD occurred in 1.7%, TV-MI occurred in 0.4%, and TLR in 0.4% of patients. The 1-year ST rate was 0.4%. Conclusions: The use of an X-position S self-apposing® stent is feasible in STEMI pPCI, with excellent post-procedural results and 1-year outcomes

Left atrial appendage occlusion in the absence of intraprocedural product specialist monitoring: is it time to proceed alone? Results from a multicenter real-world experience

BackgroundPercutaneous left atrial appendage occlusion (LAAO) presents many technical complex features, and it is often performed under the intraprocedural surveillance of a product specialist (PS). Our aim is to assess whether LAAO is equally safe and effective when performed in high-volume centers without PS support.MethodsIntraprocedural results and long-term outcome were retrospectively assessed in 247 patients who underwent LAAO without intraprocedural PS monitoring between January 2013 and January 2022 at three different hospitals. This cohort was then matched to a population who underwent LAAO with PS surveillance. The primary end point was all-cause mortality at 1 year. The secondary end point was a composite of cardiovascular mortality plus nonfatal ischemic stroke occurrence at 1 year.ResultsOf the 247 study patients, procedural success was achieved in 243 patients (98.4%), with only 1 (0.4%) intraprocedural death. After matching, we did not identify any significant difference between the two groups in terms of procedural time (70 ± 19 min vs. 81 ± 30 min, p = 0.106), procedural success (98.4% vs. 96.7%, p = 0.242), and procedure-related ischemic stroke (0.8% vs. 1.2%, p = 0.653). Compared to the matched cohort, a significant higher dosage of contrast was used during procedures without specialist supervision (98 ± 19 vs. 43 ± 21, p < 0.001), but this was not associated with a higher postprocedural acute kidney injury occurrence (0.8% vs. 0.4%, p = 0.56). At 1 year, the primary and the secondary endpoints occurred in 21 (9%) and 11 (4%) of our cohort, respectively. Kaplan–Meier curves showed no significant difference in both primary (p = 0.85) and secondary (p = 0.74) endpoint occurrence according to intraprocedural PS monitoring.ConclusionsOur results show that LAAO, despite the absence of intraprocedural PS monitoring, remains a long-term safe and effective procedure, when performed in high-volume centers

Periprocedural outcome in patients undergoing left atrial appendage occlusion with the Watchman FLX device: The ITALIAN-FLX registry

IntroductionThe Watchman FLX is a novel device for transcatheter left atrial appendage occlusion (LAAO) specifically designed to improve procedural performance in more complex anatomies with a better safety profile. Recently, small prospective non-randomized studies have shown good procedural success and safety compared with previous experiences. Results from large multicenter registries are needed to confirm the safety and efficacy of the Watchman FLX device in a real-world setting.MethodsItalian FLX registry is a retrospective, non-randomized, multicentric study across 25 investigational centers in Italy including consecutive patients undergoing LAAO with the Watchman FLX between March 2019 and September 2021 (N = 772). The primary efficacy outcome was the technical success of the LAAO procedure (peri-device flow ≤ 5 mm) as assessed by intra-procedural imaging. The peri-procedural safety outcome was defined as the occurrence of one of the following events within 7 days after the procedure or by hospital discharge: death, stroke, transient ischemic attack, major extracranial bleeding (BARC type 3 or 5), pericardial effusion with tamponade or device embolization.ResultsA total of 772 patients were enrolled. The mean age was 76 ± 8 with a mean CHA2DS2-VASc score of 4.1 ± 1.4 and a mean HAS-BLED score of 3.7 ± 1.1. Technical success was achieved in 772 (100%) patients with the first device implanted in 760 (98.4%) patients. A peri-procedural safety outcome event occurred in 21 patients (2.7%) with major extracranial bleeding being the most common (1.7%). No device embolization occurred. At discharge 459 patients (59.4%) were treated with dual antiplatelet therapy (DAPT).ConclusionsThe Italian FLX registry represents the largest multicenter retrospective real-world study reporting periprocedural outcome of LAAO with the Watchman FLX device, resulting in a procedural success rate of 100% and a low incidence of peri-procedural major adverse events (2.7%)