Most of the information operations involve users who may foster polarization and distrust toward science and mainstream journalism, without these users being conscious of their role. Gab is well ...known to be an extremist-friendly platform that performs little control on the posted content. Thus it represents an ideal benchmark for studying phenomena potentially related to polarization such as misinformation spreading. The combination of these factors may lead to hate as well as to episodes of harm in the real world. In this work we provide a characterization of the interaction patterns within Gab around the COVID-19 topic. To assess the spreading of different content type, we analyze consumption patterns based on both interaction type and source reliability. Overall we find that there are no strong statistical differences in the social response to questionable and reliable content, both following a power law distribution. However, questionable and reliable sources display structural and topical differences in the use of hashtags. The commenting behaviour of users in terms of both lifetime and sentiment reveals that questionable and reliable posts are perceived in the same manner. We can conclude that despite evident differences between questionable and reliable posts Gab users do not perform such a differentiation thus treating them as a whole. Our results provide insights toward the understanding of coordinated inauthentic behavior and on the early-warning of information operation.
Users online tend to consume information adhering to their system of beliefs and to ignore dissenting information. During the COVID-19 pandemic, users get exposed to a massive amount of information ...about a new topic having a high level of uncertainty. In this paper, we analyze two social media that enforced opposite moderation methods, Twitter and Gab, to assess the interplay between news consumption and content regulation concerning COVID-19. We compare the two platforms on about three million pieces of content analyzing user interaction with respect to news articles. We first describe users' consumption patterns on the two platforms focusing on the political leaning of news outlets. Finally, we characterize the echo chamber effect by modeling the dynamics of users' interaction networks. Our results show that the presence of moderation pursued by Twitter produces a significant reduction of questionable content, with a consequent affiliation towards reliable sources in terms of engagement and comments. Conversely, the lack of clear regulation on Gab results in the tendency of the user to engage with both types of content, showing a slight preference for the questionable ones which may account for a dissing/endorsement behavior. Twitter users show segregation towards reliable content with a uniform narrative. Gab, instead, offers a more heterogeneous structure where users, independently of their leaning, follow people who are slightly polarized towards questionable news.
Background. In 1992, the characteristics of liver cirrhosis in Italy were assessed in a cross-sectional study among 1829 cirrhosis patients attending 21 tertiary centres.
Aim. To evaluate the ...characteristics of cirrhosis patients 9 years later.
Patients. A total of 2185 consecutive cirrhosis patients were enrolled over a 6-month period in 79 hospitals located throughout Italy, randomly selected by means of systematic cluster sampling.
Results. The main agent associated with cirrhosis was hepatitis C virus, which was found in 69.9% of the patients and was the only etiologic factor in 51.1% of the patients. Hepatitis B surface antigen was present in the serum of 13.0% of the cases (in 7.3%, it was the only etiologic factor). A history of alcohol abuse was found in 31.9% of the cases (12.4% without viral infection). Patients with hepatitis C virus-related cirrhosis were older (mean age of 64.4 years) and more likely to be female (male:female ratio of 0.7), compared to patients with other pathogenic factors. Virus-related cirrhosis was more likely to be observed in southern Italy, whereas alcohol-related cirrhosis was prevalent in the North.
Conclusions. As found in the 1992 study, the results of the present study show that in Italy, liver cirrhosis is mainly associated with hepatitis C virus infection, reflecting the high prevalence of this infection in the general population.
Hydrodynamic simulations predict that a significant fraction of the gas in the current Universe is in the form of high temperature, highly ionized plasma emitting and absorbing primarily in the soft ...X-ray and UV bands, dubbed the Warm-Hot Intergalactic Medium (WHIM). Its signature should be observable in red-shifted emission and absorption lines from highly ionized elements. To determine the expected WHIM emission in the soft X-ray band we used the output of a large scale hydrodynamic SPH simulation to generate images and spectra with angular resolution of 14'' and energy resolution of 1 eV. The current biggest limit of any hydrodynamic simulation in predicting the X-ray emission comes from metal diffusion. In our investigation, by using four different models for the WHIM metallicity we have found a strong dependence of the emission on the model used, with differences up to almost an order of magnitude. For each model we have investigated the redshift distribution and angular scale of the emission, confirming that most photons come from redshift z<1.2 and that the emission has a typical angular scale of less than a few arcminutes. We also compared our simulations with the few currently available observations and found that, within the variation of the metallicity models, our predictions are in good agreement with current constraints on the WHIM emission, and at this time the weak experimental constraints on the WHIM emission are not sufficient to exclude any of the models used.
Foi realizada a caracterização e quantificação das morfologias de fitólitos (corpos micrométricos de opala biogênica) da bráctea peduncular, dos folíolos e da ráquila de Bactris setosa Mart. e ...Geonoma schottiana Mart. (Arecaceae que tem ocorrência na Mata Atlântica). A extração foi realizada via dissolução ácida, posteriormente os fitólitos foram contados (400 grãos/ lâmina, 3 lâminas por estrutura vegetal), foi realiza a medição de seus diâmetros e corte histológico dos folíolos. B. setosa apresentou de maneira predominante (>98% de ocorrência) o fitólito “conical echinate”, com diâmetros tem variação entre 4,04 - 19,73µm e comprimentos entre 0,65-3,21µm para suas estruturas vegetais, tal morfologia apresenta-se disposta alinhada longitudinalmente no folíolo. Em G. schottiana o fitólito predominante é “globular echinate” (>98,5%), com diâmetros A que variam entre 4,41-13,07µm e diâmetro B 5,84-24,28µm, os fitólitos estão dispostos no folíolo de maneira alinhada horizontal e transversalmente.
Recent analyses of the fluctuations of the soft Diffuse X-ray Background (DXB) have provided indirect detection of a component consistent with the elusive Warm Hot Intergalactic Medium (WHIM). In ...this work we use theoretical predictions obtained from hydrodynamical simulations to investigate the angular correlation properties of the WHIM in emission and assess the possibility of indirect detection with next-generation X-ray missions. Our results indicate that the angular correlation signal of the WHIM is generally weak but dominates the angular correlation function of the DXB outside virialized regions. Its indirect detection is possible but requires rather long exposure times 0.1-1 Ms, large (~1{\deg} x1{\deg}) fields of view and accurate subtraction of isotropic fore/background contributions, mostly contributed by Galactic emission. The angular correlation function of the WHIM is positive for {\theta} < 5' and provides limited information on its spatial distribution. A satisfactory characterization of the WHIM in 3D can be obtained through spatially resolved spectroscopy. 1 Ms long exposures with next generation detectors will allow to detect ~400 O VII+O VIII X-ray emission systems that we use to trace the spatial distribution of the WHIM. We predict that these observations will allow to estimate the WHIM correlation function with high statistical significance out to ~10 Mpc h^-1 and characterize its dynamical state through the analysis of redshift-space distortions. The detectable WHIM, which is typically associated with the outskirts of virialized regions rather than the filaments has a non-zero correlation function with slope {\gamma} = -1.7 \pm 0.1 and correlation length r0 = 4.0 \pm 0.1 Mpc h^-1 in the range r = 4.5, 12 Mpc h^-1. Redshift space distances can be measured to assess the dynamical properties of the gas, typically infalling onto large virialized structures.
The backbone of the large-scale structure of the Universe is determined by processes on a cosmological scale and by the gravitational interaction of the dominant dark matter. However, the mobile ...baryon population shapes the appearance of these structures. Theory predicts that most of the baryons reside in vast unvirialized filamentary structures that connect galaxy groups and clusters, but the observational evidence is currently lacking. Because the majority of the baryons are supposed to exist in a large-scale, hot and dilute gaseous phase, X-rays provide the ideal tool to progress our understanding. Observations with the Athena+ X-ray Integral Field Unit will reveal the location, chemical composition, physical state and dynamics of the active population of baryons.
Long-term beta-blockade is said to increase the number of beta-receptors. The effect of beta-blockers could therefore be reduced after long use. We tested this hypothesis in nine healthy subjects ...given 15 mg pindolol daily for 4 wk. Plasma concentrations (measured fluorometrically), isoproterenol dose-response relationship (to calculate the dose needed to increase heart rate by 25 bpm), renin, epinephrine, and norepinephrine were measured several times before and after the first and last dose. Kinetic parameters remained stable: total clearance (Cltot) = 45.2 and 42.9 l/hr, and Vdss = 205.8 and 198.6 l after the first and last dose. The concentration-effect relationship, plotted as the "dose ratio minus one" against the log of the plasma concentration was identical after 4 wk. Basal plasma renin activity was reduced slightly and the increase of stimulated plasma renin was blunted by pindolol even after 4 wk. The initial lowering of unstimulated renin by pindolol in the first 2 hr after dosing was not detectable after 4 wk. Epinephrine and norepinephrine levels in plasma were not changed initially nor after 4 wk. It is concluded that pindolol has a stable kinetic profile over time and that its beta-blockade does not induce tachyphylaxis.
We assess the possibility to detect the warm-hot intergalactic medium (WHIM) in emission and to characterize its physical conditions and spatial distribution through spatially resolved X-ray ...spectroscopy, in the framework of the recently proposed DIOS, EDGE, Xenia, and ORIGIN missions, all of which are equipped with microcalorimeter-based detectors. For this purpose we analyze a large set of mock emission spectra, extracted from a cosmological hydrodynamical simulation. These mock X-ray spectra are searched for emission features showing both the OVII K alpha triplet and OVIII Ly alpha line, which constitute a typical signature of the warm hot gas. Our analysis shows that 1 Ms long exposures and energy resolution of 2.5 eV will allow us to detect about 400 such features per deg^2 with a significance >5 sigma and reveals that these emission systems are typically associated with density ~100 above the mean. The temperature can be estimated from the line ratio with a precision of ~20%. The combined effect of contamination from other lines, variation in the level of the continuum, and degradation of the energy resolution reduces these estimates. Yet, with an energy resolution of 7 eV and all these effects taken into account, one still expects about 160 detections per deg^2. These line systems are sufficient to trace the spatial distribution of the line-emitting gas, which constitute an additional information, independent from line statistics, to constrain the poorly known cosmic chemical enrichment history and the stellar feedback processes.
Long‐term β‐blockade is said to increase the number of β‐receptors. The effect of β‐blockers could therefore be reduced after long use. We tested this hypothesis in nine healthy subjects given 15 mg ...pindolol daily for 4 wk. Plasma concentrations (measured fluorometrically), isoproterenol dose‐response relationship (to calculate the dose needed to increase heart rate by 25 bpm), renin, epinephrine, and norepinephrine were measured several times before and after the first and last dose. Kinetic parameters remained stable: total clearance (Cltot) = 45.2 and 42.9 l/hr, and Vdss = 205.8 and 198.6 l after the first and last dose. The concentration‐effect relationship, plotted as the “dose ratio minus one” against the log of the plasma concentration was identical after 4 wk. Basal plasma renin activity was reduced slightly and the increase of stimulated plasma renin was blunted by pindolol even after 4 wk. The initial lowering of unstimulated renin by pindolol in the first 2 hr after dosing was not detectable after 4 wk. Epinephrine and norepinephrine levels in plasma were not changed initially nor after 4 wk. It is concluded that pindolol has a stable kinetic profile over time and that its β‐blockade does not induce tachyphylaxis.
Clinical Pharmacology and Therapeutics (1983) 33, 733–740; doi:10.1038/clpt.1983.100
PDF
