Simulations of stripped core-collapse supernovae in close binaries

We perform smoothed-particle hydrodynamical simulations of the explosion of a helium star in a close binary system, and study the effects of the explosion on the companion star as well as the effect of the presence of the companion on the supernova remnant. By simulating the mechanism of the supernova from just after core bounce until the remnant shell passes the stellar companion, we are able to separate the various effects leading to the final system parameters. In the final system, we measure the mass stripping and ablation from, and the velocity kick imparted to, the companion star, as well as the structure of the supernova shell. The presence of the companion star produces a conical cavity in the expanding supernova remnant, and loss of material from the companion causes the supernova remnant to be more metal-rich on one side and more hydrogen-rich (from the companion material) around the cavity. Following the removal of mass from the companion, we study its subsequent evolution and compare it with a single star not subjected to a supernova impact.Comment: 20 pages, 14 figures, submitted to Computational Astrophysics and Cosmolog

D2.1 User requirements and needs and gaps analysis report

This report has been submitted by Fondazione Scuola di Pace di Monte Sole (Italy) as deliverable D2.1 within the framework of H2020 project "SO-CLOSE: Enhancing Social Cohesion through Sharing the Cultural Heritage of Forced Migrations" Grant No. 870939.This report illustrates the main findings of the SO-CLOSE WP2 collective research, based on participatory methods and group reflections (co-creation and focus groups).The idea is to enlighten coherences and resources as well as questionable and problematic points, in order to help WP3, WP4 and WP5 with new and tested ideas together with suggestions to mitigate possible obstacles, misunderstandings and mistakes. The text starts illustrating a short analytical premise and it then covers the 4 main SO-CLOSE fields of interest: historical memory, social cohesion, cultural heritage and methods and tools for sharing between native and refugee/asylum seekers communities

A Qualitative Comparison of First and Follow-Up Visits

UIDB/00183/2020 UIDP/00183/2020 SFRH/BPD/115073/2016 PTDC/FER-FIL/28278/2017Background: Misunderstandings in medical interactions can compromise the quality of communication and affect self-management, especially in complex interactions like those in the assisted reproductive technology (ART) field. This study aimed to detect and describe misunderstandings in ART triadic visits. We compared first and follow-up visits for frequency, type, speakers, and topics leading to misunderstandings. Methods: We purposively sampled 20 triadic interactions from a corpus of 85 visits. We used a previously developed coding scheme to detect different types of misunderstandings (i.e., with strong, acceptable, and weak evidence). We analyzed also the different topics leading to strong misunderstandings (direct expressions of lack of understanding, pragmatic alternative understandings, semantic alternative understandings) to provide insights about the contents of the consultation that may need particular attention and care. Findings: We detected an overall number of 1078 misunderstandings in the 20 selected visits. First visits contained almost two-third of the misunderstandings (n = 680, 63%). First visits were particularly rich in misunderstandings with acceptable evidence (e.g., clarifications and checks for understanding), compared to follow-up visits. In first visits, doctors’ turns more frequently than couples’ turns contained misunderstandings, while in follow-up visits it was the other way around. Looking at the couple, the majority of the misunderstandings were expressed by the woman (n = 241, 22%) rather than by the man (n = 194, 18%). However, when weighting for their number of turns, 9% of the men’s turns included an expression of misunderstanding, compared to the 7% of the women’s turns. Finally, more than half of the misunderstandings with strong evidence were about history-taking and treatment-related topics, and while the history-taking ones were particularly frequent in first visits the treatment-related ones were more present in follow-up visits. Discussion: Findings indicate that first visits may deserve particular attention to avoid misunderstandings, as they are the moment where a shared understanding can be harder to reach. In particular, misunderstandings happening in first visits seem mostly related to physicians having to reconstruct the clinical history of patients, while those in the follow-up visits seem to reflect residual and unsolved doubts from the couple, especially concerning treatments.publishersversionpublishe

Collection, storage and freezability of equine epididymal spermatozoa

The recovery of spermatozoa from the cauda epididymis may be the last chance to obtain genetic material from stallions undergone to castration. The aim of the current study was to evaluate the efficiency of cryopreservation and the use of two different extenders for equine epididymal spermatozoa. Testicles obtained from castration were divided into two groups: cauda epididymis processed immediately after orchiectomy and cauda epididymis processed after 24 h storage in saline solution at 4 °C of the testis. The epididymal spermatozoa were collected through manual slicing of the cauda epididymis of each testicle. In addition, spermatozoa obtained from different processed testes were diluted alternatively with either modified Palmer or EGG TECH® extenders to produce frozen straws. Motility parameters in fresh and frozen-thawed material were analysed by means of the computer-aided sperm analysis (CASA). The recorded CASA data were analysed with a mixed linear model. Motility parameters in fresh semen yielded better results than in frozen semen (p = 0.008), but no difference (p > 0.05) was observed between spermatozoa collected immediately after castration or after 24 h of storage; in frozen-thawed samples, EGG TECH® tended to improve the percentage of progressively motile spermatozoa in epididymal frozen-thawed semen (p = 0.08) compared with modified Palmer. We conclude that the processing of epididymal spermatozoa can occur up to 24 h after stallion castration and both common extenders used are suitable for preserving this material

Role of coenzyme Q and vitamin E on stallion semen motility evaluated both in frozen and cooled-stored semen

Several studies reveal that coenzyme Q (CoQ) and vitamin E (Vit. E) act against oxidative deterioration, and that CoQ restores the active and antioxidant form of Vit. E. These two antioxidants, acting against lipid peroxidation, seem to be able to improve motility parameters of spermatozoa. The objective of this study is to evaluate the addition of CoQ and Vit. E to semen extender for equine spermatozoa in order to evaluate possible effects on semen motility. First, immediately after collection, semen samples were diluted with 1mM of CoQ and 1mM of CoQ plus 1mM of Vit. E and prepared for frozen storage in liquid nitrogen. After thawing (37 °C/30 s), samples were maintained at 37 °C and subjected to analysis after 0, 2 and 4 h for motility parameters with CASA (Computer-Assisted Sperm Analysis) method. In a second experiment, after the collection, semen samples were diluted with 1mM of CoQ, in presence or absence of seminal plasma where Vit. E is normally present, and prepared for cooled storage at 4 °C. The effects on motility parameters were determined with CASA at 0, 24, 31 and 48 h after collection. During the analysis, samples were kept at 4 °C. The CASA variables were examined with a mixed linear model. No improvement (p > .05) in motility parameters results from the addition of CoQ and Vit. E in frozen or cooled-stored equine semen when compared to control group

The most luminous AGN do not produce the majority of the detected stellar-mass black hole binary mergers in the local Universe

Despite the increasing number of Gravitational Wave (GW) detections, the astrophysical origin of Binary Black Hole (BBH) mergers remains elusive. A promising formation channel for BBHs is inside accretion discs around supermassive black holes, that power Active Galactic Nuclei (AGN). In this paper, we test for the first time the spatial correlation between observed GW events and AGN. To this end, we assemble all sky catalogues with 1,412 (242) AGN with a bolometric luminosity greater than $10^{45.5} {\rm erg\ s}^{-1}$ ($10^{46}\,{\rm erg\,s}^{-1}$) with spectroscopic redshift of $z\leq0.3$ from the Milliquas catalogue, version 7.7b. These AGN are cross-matched with localisation volumes of BBH mergers observed in the same redshift range by the LIGO and Virgo interferometers during their first three observing runs. We find that the fraction of the detected mergers originated in AGN brighter than $10^{45.5}\,{\rm erg\,s}^{-1}$ ($10^{46}\,{\rm erg\,s}^{-1}$) cannot be higher than $0.49$ ($0.17$) at a 95 per cent credibility level. Our upper limits imply a limited BBH merger production efficiency of the brightest AGN, while most or all GW events may still come from lower luminosity ones. Alternatively, the AGN formation path for merging stellar-mass BBHs may be actually overall subdominant in the local Universe. To our knowledge, ours are the first observational constraints on the fractional contribution of the AGN channel to the observed BBH mergers.Comment: 11 pages, 5 figures, 2 table

Accelerated aging in perinatally HIV-infected children: clinical manifestations and pathogenetic mechanisms

BACKGROUND: Premature aging and related diseases have been documented in HIV-infected adults. Data are now emerging also regarding accelerated aging process in HIV-infected children. METHODS: A narrative review was performed searching studies on PubMed published in English language in 2004-2017, using appropriate key words, including "aging", "children", "HIV", "AIDS", "immunosenescence", "pathogenesis", "clinical conditions". RESULTS: Premature immunosenescence phenotype of B and T cells in HIV-infected children is mediated through immune system activation and chronic inflammation. Ongoing inflammation processes have been documented by increased levels of pathogen-associated molecular patterns (PAMPS), increased mitochondrial damage, higher levels of pro-inflammatory cytokines, and a positive correlation between sCD14 levels and percentages of activated CD8+ cells. Other reported features of premature aging include cellular replicative senescence, linked to an accelerated telomeres shortening. Finally, acceleration of age-associated methylation pattern and other epigenetic modifications have been described in HIV-infected children. All these features may favor the clinical manifestations related to premature aging. Lipid and bone metabolism, cancers, cardiovascular, renal, and neurological systems should be carefully monitored, particularly in children with detectable viremia and/or with CD4/CD8 ratio inversion. CONCLUSION: Aging processes in children with HIV infection impact their quality and length of life. Further studies regarding the mechanisms involved in premature aging are needed to search for potential targets of treatment

Experimental investigation on CO2methanation process for solar energy storage compared to CO2-based methanol synthesis

The utilization of the captured CO2 as a carbon source for the production of energy storage media offers a technological solution for overcoming crucial issues in current energy systems. Solar energy production generally does not match with energy demand because of its intermittent and non-programmable nature, entailing the adoption of storage technologies. Hydrogen constitutes a chemical storage for renewable electricity if it is produced by water electrolysis and is also the key reactant for CO2 methanation (Sabatier reaction). The utilization of CO2 as a feedstock for producing methane contributes to alleviate global climate changes and sequestration related problems. The produced methane is a carbon neutral gas that fits into existing infrastructure and allows issues related to the aforementioned intermittency and non-programmability of solar energy to be overcome. In this paper, an experimental apparatus, composed of an electrolyzer and a tubular fixed bed reactor, is built and used to produce methane via Sabatier reaction. The objective of the experimental campaign is the evaluation of the process performance and a comparison with other CO2 valorization paths such as methanol production. The investigated pressure range was 2–20 bar, obtaining a methane volume fraction in outlet gaseous mixture of 64.75% at 8 bar and 97.24% at 20 bar, with conversion efficiencies of, respectively, 84.64% and 99.06%. The methanol and methane processes were compared on the basis of an energy parameter defined as the spent energy/stored energy. It is higher for the methanol process (0.45), with respect to the methane production process (0.41–0.43), which has a higher energy storage capability