The recent gravitational wave observation by pulsar timing arrays and primordial black holes: the importance of non-gaussianities

The recent data releases by multiple pulsar timing array experiments (NANOGrav, EPTA, PPTA and CPTA) show evidence for Hellings-Downs angular correlations indicating that the observed stochastic common spectrum can be interpreted as a stochastic gravitational wave background. In this letter, we study whether the signal may originate from gravitational waves induced by high-amplitude primordial curvature perturbations. Such large perturbations may be accompanied by the generation of a sizeable primordial black hole (PBH) abundance. We improve existing analyses of the PBH abundance by including non-Gaussianities typical of several scenarios such as curvaton and inflection-point models. We show that Gaussian scenarios for scalar-induced gravitational waves are disfavoured by more than 2{\sigma} as the sole explanation of the most constraining NANOGrav 15-year data by the overproduction of PBHs. This excludes most explanations relying on single-field inflation by more than 3{\sigma}. This tension, however, can be alleviated in models in which non-Gaussianites suppress the PBH abundance, for instance, in curvaton models with a large rdec or models with a negative fNL. On the flip side, the current NANOGrav data does not constrain the abundance of PBHs in the stellar mass range.Comment: 6 pages and 3 figures. Supplementary materials availabl

Primordial black holes in the curvaton model: possible connections to pulsar timing arrays and dark matter

We revise primordial black holes (PBHs) production in the axion-curvaton model, in light of recent developments in the computation of their abundance accounting for non-gaussianities (NGs) in the curvature perturbation up to all orders. We find that NGs intrinsically generated in such scenarios have a relevant impact on the phenomenology associated to PBHs and, in particular, on the relation between the abundance and the signal of second-order gravitational waves. We show that this model could explain both the totality of dark matter in the asteroid mass range and the tentative signal reported by the NANOGrav and IPTA collaborations in the nano-Hz frequency range. En route, we provide a new, explicit computation of the power spectrum of curvature perturbations going beyond the sudden-decay approximation.Comment: 25 pages, 11 figure

The importance of sports education in the primary school: An experimental pedagogical project

The educational role of sport in the various socio-relational contexts is now an internationally consolidated reality; however, in the Italian school context, especially at primary level, sports activity still does not have the possibility to express all its pedagogical potential. In this regard, this research work aims at proving the ability to develop indispensable skills for a complete growth of children, through a pedagogical experimental project in the field of motor-sports education at school level. This research work involves a heterogeneous class of a primary school, and was carried out within a limited period of time during school hours. Its outcomes confirm the basic hypothesis, and are proposed as a solid basis for future studies in experimental pedagogy applied to the field of motor and sports sciences

Experimental evaluation of the school well-being improvement for primary school students through a water polo sports laboratory

The concept of well-being can be now extended to all social environments that provide a relational system between the various individuals, and among these environments, one of the most important is certainly school. The purpose of this contribution is to show the concept of school well-being and then analyze if an experimental proposal of a sports laboratory could be an effective pedagogical strategy, capable of improving the level of well-being for students. In this regard, at primary school level, a laboratory activity on water polo was provided, and through the QBS-B questionnaire, the change in the level of school well-being perceived by the students, from the "pre" Laboratory period to the "post" one, was assessed

Tagging genes with cassette-exchange sites

In an effort to make transgenesis more flexible and reproducible, we developed a system based on novel 5′ and 3′ ‘gene trap’ vectors containing heterospecific Flp recognition target sites and the corresponding ‘exchange’ vectors allowing the insertion of any DNA sequence of interest into the trapped locus. Flp-recombinase-mediated cassette exchange was demonstrated to be highly efficient in our system, even in the absence of locus-specific selection. The feasibility of constructing a library of ES cell clones using our gene trap vectors was tested and a thousand insertion sites were characterized, following electroporation in ES cells, by RACE–PCR and sequencing. We validated the system in vivo for two trapped loci in transgenic mice and demonstrated that the reporter transgenes inserted into the trapped loci have an expression pattern identical to the endogenous genes. We believe that this system will facilitate in vivo studies of gene function and large-scale generation of mouse models of human diseases, caused by not only loss but also gain of function alleles

Automated provenance graphs for [email protected]

Software systems are increasingly making decisions autonomously by incorporating AI and machine learning capabilities. These systems are known as self-adaptive and autonomous systems (SAS). Some of these decisions can have a life-changing impact on the people involved and therefore, they need to be appropriately tracked and justified: the system should not be taken as a black box. It is required to be able to have knowledge about past events and records of history of the decision making. However, tracking everything that was going on in the system at the time a decision was made may be unfeasible, due to resource constraints and complexity. In this paper, we propose an approach that combines the abstraction and reasoning support offered by models used at runtime with provenance graphs that capture the key decisions made by a system through its execution. Provenance graphs relate the entities, actors and activities that take place in the system over time, allowing for tracing the reasons why the system reached its current state. We introduce activity scopes, which highlight the high-level activities taking place for each decision, and reduce the cost of instrumenting a system to automatically produce provenance graphs of these decisions. We demonstrate a proof of concept implementation of our proposal across two case studies, and present a roadmap towards a reusable provenance layer based on the experiments

What is the source of the PTA GW signal?

The most conservative interpretation of the nHz stochastic gravitational wave background (SGWB) discovered by NANOGrav and other Pulsar Timing Array (PTA) Collaborations is astrophysical, namely that it originates from supermassive black hole (SMBH) binaries. However, alternative cosmological models have been proposed, including cosmic strings, phase transitions, domain walls, primordial fluctuations and "audible" axions. We perform a multi-model analysis (MMA) to compare how well these different hypotheses fit the NANOGrav data, both in isolation and in combination with SMBH binaries, and address the questions: Which interpretations fit the data best, and which are disfavoured? We also discuss experimental signatures that can help discriminate between different sources of the PTA GW signal, including fluctuations in the signal strength between frequency bins, individual sources and how the PTA signal extends to higher frequencies.Comment: 15 pages, 17 figures, 1 tabl

Psychometric testing of the caregiver contribution to self-care of coronary heart disease inventory

Background: Caregivers are important contributors to the self-care of patients with coronary heart disease (CHD). Aims: The aims of this study are to describe the development and psychometric properties of the caregiver contribution to self-care of coronary heart disease inventory (CC-SC-CHDI). Methods: The CC-SC-CHDI was developed from the patient version of the scale, the Self-care of Coronary Heart Disease Inventory (SC-CHDI) and translated into Italian using forward and backward translation. Baseline data from the HEARTS-IN-DYADS study were used. Confirmatory factor analysis (CFA) was conducted to assess factorial validity; Cronbach's alpha and the model-based internal consistency index were used to test internal consistency reliability, and Pearson's correlation coefficient was used to test convergent validity, by investigating the association between the CC-SC-CHDI and the SC-CHDI scores. Results: We included 131 caregivers (mean age 55 years, 81.2% females, 74% married) of patients affected by CHD (mean age 66 years, 80.2% males, 74% married). The CFA confirmed two factors in the caregiver contribution to self-care maintenance scale ("consulting behaviors" and "autonomous behaviors"), one factor for the CC to self-care monitoring scale, and two factors in the CC to self-care management scale ("consulting behaviors and problem-solving behaviors"). Reliability estimates were adequate for each scale (Cronbach's alpha and model-based internal consistency indexes ranging from 0.73 to 0.90). Significant and positive correlations were observed between CC-SC-CHDI and SC-CHDI scales. Conclusion: The CC-SC-CHDI has satisfactory validity and reliability and can be used confidently in clinical settings and research to assess caregiver contributions to CHD self-care

Global mean climate and main patterns of variability in the CMCC-CM2 coupled model

Euro‐Mediterranean Centre on Climate Change coupled climate model (CMCC‐CM2) represents the new family of the global coupled climate models developed and used at CMCC. It is based on the atmospheric, land and sea ice components from the Community Earth System Model coupled with the global ocean model Nucleus for European Modeling of the Ocean. This study documents the model components, the coupling strategy, particularly for the oceanic, atmospheric, and sea ice components, and the overall model ability in reproducing the observed mean climate and main patterns of interannual variability. As a first step toward a more comprehensive, process‐oriented, validation of the model, this work analyzes a 200‐year simulation performed under constant forcing corresponding to present‐day climate conditions. In terms of mean climate, the model is able to realistically reproduce the main patterns of temperature, precipitation, and winds. Specifically, we report improvements in the representation of the sea surface temperature with respect to the previous version of the model. In terms of mean atmospheric circulation features, we notice a realistic simulation of upper tropospheric winds and midtroposphere geopotential eddies. The oceanic heat transport and the Atlantic meridional overturning circulation satisfactorily compare with present‐day observations and estimates from global ocean reanalyses. The sea ice patterns and associated seasonal variations are realistically reproduced in both hemispheres, with a better skill in winter. Main weaknesses of the simulated climate are related with the precipitation patterns, specifically in the tropical regions with large dry biases over the Amazon basin. Similarly, the seasonal precipitation associated with the monsoons, mostly over Asia, is weaker than observed. The main patterns of interannual variability in terms of dominant empirical orthogonal functions are faithfully reproduced, mostly in the Northern Hemisphere winter. In the tropics the main teleconnection patterns associated with El Niño–Southern Oscillation and with the Indian Ocean Dipole are also in good agreement with observations.Published4A. Oceanografia e climaJCR Journa

Oncologic outcomes following laparoscopic colon cancer resection for T4 lesions: a case-control analysis of 7-years' experience

According to many Societies' guidelines, patients presenting with clinical T4 colorectal cancer should conventionally be approached by a laparotomy. Results of emerging series are questioning this attitude