Coexistence of Magneto-Rotational and Jeans Instabilities in an Axisymmetric Nebula

We analyze the magneto-rotational instability (MRI) effects on gravitational collapse and its influence on the instability critical scale. In particular, we study an axisymmetric nonstratified differentially rotating cloud, embedded in a small magnetic field, and we perform a local linear stability analysis, including the self gravity of the system. We demonstrate that the linear evolution of the perturbations is characterized by the emergence of an anisotropy degree of the perturbed mass densities. Starting with spherical growing overdensities, we see that they naturally acquire an anisotropy of order unity in their shape. Despite the linear character of our analysis, we infer that such a seed of anisotropy can rapidly grow in a nonlinear regime, leading to the formation of filament-like structures. However, we show how such an anisotropy is essentially an intrinsic feature of the Jean instability, and how MRI only plays a significant role in fixing the critical scale of the mode spectrum. We then provide a characterization of the present analysis in terms of the cosmological setting, in order to provide an outlook of how the present results could concern the formation of large-scale structures across the Universe.Comment: 8 pages, 4 figure

Minimally-invasive treatments for benign thyroid nodules: recommendations for information to patients and referring physicians by the Italian Minimally-Invasive Treatments of the Thyroid group

Purpose: In this paper, the members of the Italian Working Group on Minimally-Invasive Treatments of the Thyroid (MITT group) aim to summarize the most relevant information that could be of help to referring physicians and that should be provided to patients when considering the use of MITT for the treatment of benign thyroid nodules. Methods: An interdisciplinary board of physicians with specific expertise in the management of thyroid nodules was appointed by the Italian MITT Group. A systematic literature search was performed, and an evidence-based approach was used, including also the knowledge and the practical experience of the panelists to develop the paper. Results: The paper provides a list of questions that are frequently asked by patients to operators performing MITT, each with a brief and detailed answer and more relevant literature references to be consulted. Conclusions: This paper summarizes the most relevant information to be provided to patients and general practitioners/referring physicians about the use of MITT for the treatment of benign thyroid nodules

Spontaneous Opinion Swings in the Voter Model with Latency

The cognitive process of opinion formation is often characterized by stubbornness or resistance of agents to changes of opinion. To capture such a feature we introduce a constant latency time in the standard voter model of opinion dynamics: after switching opinion, an agent must keep it for a while. This seemingly simple modification drastically changes the stochastic diffusive behavior of the original model, leading to deterministic dynamical oscillations in the average opinion of the agents. We explain the origin of the oscillations and develop a mathematical formulation of the dynamics that is confirmed by extensive numerical simulations. We further characterize the rich phase space of the model and its asymptotic behavior. Our work offers insights into understanding and modeling opinion swings in diverse social contexts

The rise and fall of WallStreetBets: social roles and opinion leaders across the GameStop saga

Nowadays human interactions largely take place on social networks, with online users' behavior often falling into a few general typologies or "social roles". Among these, opinion leaders are of crucial importance as they have the ability to spread an idea or opinion on a large scale across the network, with possible tangible consequences in the real world. In this work we extract and characterize the different social roles of users within the Reddit WallStreetBets community, around the time of the GameStop short squeeze of January 2021 -- when a handful of committed users led the whole community to engage in a large and risky financial operation. We identify the profiles of both average users and of relevant outliers, including opinion leaders, using an iterative, semi-supervised classification algorithm, which allows us to discern the characteristics needed to play a particular social role. The key features of opinion leaders are large risky investments and constant updates on a single stock, which allowed them to attract a large following and, in the case of GameStop, ignite the interest of the community. Finally, we observe a substantial change in the behavior and attitude of users after the short squeeze event: no new opinion leaders are found and the community becomes less focused on investments. Overall, this work sheds light on the users' roles and dynamics that led to the GameStop short squeeze, while also suggesting why WallStreetBets no longer wielded such large influence on financial markets, in the aftermath of this event.Comment: main text: 15 pages, 4 figures. supplementary materials: 15 pages, 12 figure

Cigarette smoking affects the differences between male and female phenotypes

Sex-gender medicine focuses on differences and similarities in health and disease between men and women. The present study focused on the existence of male and female phenotypes when routine demographic, biochemical and haematological data are considered and aimed to determine the influence of smoking on phenotypes and evaluate the role of body weight on sex-gender differences in view of the fact that some of them can be utilized as biomarkers of diagnosis, diseases and therapeutic response

Prevalence and predictors of left ventricular hypertrophy in patients with hypertension and normal electrocardiogram

Background: Electrocardiography (ECG) has low sensitivity for detecting left ventricular hypertrophy (LVH), while echocardiography cannot be routinely performed. Design/methods: In this study we evaluate the prevalence of LVH and diastolic dysfunction in hypertensive patients with normal ECG. We excluded patients with cardiovascular (CV) diseases, diabetes, chronic kidney disease, or presenting ECG-LVH or other ECG anomalies. The enrolled 440 hypertensive patients underwent echocardiographic examination (Acuson Sequoia 512); LV mass was indexed by body surface area (LVMI) and LVH was defined as LVMI >125 g/m2 in men and >110 g/m2 in women. Diastolic function was evaluated by mitral inflow and tissue Doppler imaging (TDI). Results: The prevalence of LVH was 8.18% (95% confidence interval [CI] 5.97–11.1%). Multiple regression analysis showed that the only variable independently associated with LVH was duration of hypertension (p<0.001). The receiver operating characteristic (ROC) curve showed that duration of hypertension was a powerful predictor of LVH, with an area under the curve (AUC) of 0.878 and p<0.0001. Further, in patients with LVH the mean difference of LVMI from the cut-off value for LVH was 12.3 9.19 g/m2. Diastolic dysfunction, defined as early diastolic myocardial velocity (Em) <0.08 m/s, was detected only in 3.2% of patients. Conclusions: The prevalence of LVH among hypertensive patients with normal ECG, free of diabetes and of CV diseases is low; moreover, patients with echocardiographic LVH presented LVMI values that identified mild LVH. Few cases of impaired diastolic function were registered. We suggest that in hypertensive patients with such characteristics the echocardiographic examination should be reserved to those who present with higher duration of hypertension

Multi-objective co-exploration of source code transformations and design space architectures for low-power embedded systems

The exploration of the architectural design space in terms of energy and performance is of mainly importance for a broad range of embedded platforms based on the System-On-Chip approach. This paper proposes a methodology for the co-exploration of the design space composed of architec-tural parameters and source program transformations. A heuristic technique based on Pareto Simulated Annealing (PSA) has been used to efficiently span the multi-objective co-design space composed of the product of the parame-ters related to the selected program transformations and the configurable architecture. The analysis of the proposed framework has been carried out for a parameterized super-scalar architecture executing a selected set of benchmarks. The reported results show the effectiveness of the proposed co-exploration with respect to the independent exploration of the transformation and architectural spaces to efficiently derive approximate Pareto curves