Exploring Time-Sensitive Variational Bayesian Inference LDA for Social Media Data

There is considerable interest among both researchers and the mass public in understanding the topics of discussion on social media as they occur over time. Scholars have thoroughly analysed sampling-based topic modelling approaches for various text corpora including social media; however, another LDA topic modelling implementation—Variational Bayesian (VB)—has not been well studied, despite its known efficiency and its adaptability to the volume and dynamics of social media data. In this paper, we examine the performance of the VB-based topic modelling approach for producing coherent topics, and further, we extend the VB approach by proposing a novel time-sensitive Variational Bayesian implementation, denoted as TVB. Our newly proposed TVB approach incorporates time so as to increase the quality of the generated topics. Using a Twitter dataset covering 8 events, our empirical results show that the coherence of the topics in our TVB model is improved by the integration of time. In particular, through a user study, we find that our TVB approach generates less mixed topics than state-of-the-art topic modelling approaches. Moreover, our proposed TVB approach can more accurately estimate topical trends, making it particularly suitable to assist end-users in tracking emerging topics on social media

Second-Order Likelihood-Based Inference in Mixed-Effects Models.

This paper focuses on the application of higher-order asymptotics for likelihood-based inference to mixed-effects models. In particular, for a scalar parameter of interest, the modified directed likelihood of Skovgaard (1996) is considered. Its expression in linear and nonlinear mixed-effects models with a single level of grouping is derived, starting from the results of Lyons and Peters (2000). Some simulation studies demonstrate the improvements that can be obtained by using this statistic with respect to first-order methods

Osteopathic Manipulative Treatment and Cardiovascular Autonomic Parameters in Rugby Players: A Randomized, Sham-Controlled Trial

Objective: The purpose of this study was to investigate the effects of osteopathic manipulative treatment (OMT) on cardiovascular autonomic parameters after a rugby match. Methods: Resting and reactivity (ie, response to orthostasis) measures of mean arterial pressure, heart rate, and heart rate variability were assessed in 23 male players after a single session of OMT, both 18 to 20 hours after a rugby match and in a corresponding no-match condition, in a randomized, sham-controlled, crossover design. Results: Signs of reduced heart rate variability and elevated mean arterial pressure and heart rate were found 18 to 20 hours after a rugby match compared with the no-match condition. A significant increase in heart rate variability and a significant reduction in mean arterial pressure were observed after OMT in both the after-match and no-match conditions. Heart rate and heart rate variability responses to orthostasis were not affected by previous match competition, but were significantly larger after OMT compared with sham treatment. Conclusion: This study suggests the presence of cardiovascular autonomic alterations in rugby players after a competitive match, which may be indicative of prolonged fatigue and incomplete recovery. In these players, favorable changes in cardiovascular autonomic parameters were observed following a single session of OMT

The R Package metaLik for Likelihood Inference in Meta-Analysis

Meta-analysis is a statistical method for combining information from different studies about the same issue of interest. Meta-analysis is widely diffuse in medical investigation and more recently it received a growing interest also in social disciplines. Typical applications involve a small number of studies, thus making ordinary inferential methods based on first-order asymptotics unreliable. More accurate results can be obtained by exploiting the theory of higher-order asymptotics. This paper describes the metaLik package which provides an R implementation of higher-order likelihood methods in meta-analysis. The extension to meta-regression is included. Two real data examples are used to illustrate the capabilities of the package

Pattern and characteristics of advanced cancer patients admitted to hospices in Italy

Abstract The aim of this multicenter study was to assess the pattern and the characteristics of advanced cancer patients admitted to hospices. A consecutive sample of patients admitted in a period of 6 months was taken into consideration. Two hundred thirty-six patients admitted to hospices were consecutively assessed. Ninety-six percent of patients were admitted in acute hospital in the previous 3 months, with a mean time spent in hospital of 34.5 days, and 47 % of patients had received chemotherapy the month before hospice admission. Thirty-four percent of patients for whom data were available had significant persistent pain, and 44 % of them presented episodes of breakthrough pain. Sixty-one percent of patients were receiving opioid drugs at admission, and 70 % the day before death, with parenteral morphine and transdermal fentanyl being the opioids most frequently administered. The mean admission time in hospice was 18.4 days. Eighty-six percent died in hospice. Palliative sedation was performed in 25 % of patients who died in hospice. The short survival and the number of patients dying in hospice were the principal finding, as it appears that hospice admission is only one way for end of life treatments. Patients receive specialized palliative care only for 2-3 weeks before death, implying an inacceptable timing for patients with several problems presumed to be present early during the course of disease. Data from hospice activities in Italy strongly suggest to spread palliative care in other settings, other than home care and hospice, to intercept oncologic patients in their disease trajectory early

Hospitalization for acute cerebellitis in children affected by varicella: how much does it cost?

Background Chickenpox is a highly contagious airborne disease caused by the varicella zoster virus. It is generally benign and self-limiting, but it may be responsible of life-threatening complications. Acute cerebellitis (AC) is the most common neurological complication and is associated with prolonged hospitalization in the acute phase (HAP). Aim of the study To estimate the costs of AC HAP in children affected by varicella. Materials and methods We retrospectively reviewed the medical records of a pediatric cohort hospitalized for chickenpox AC over a period of 15 years (from October 2003 to October 2018) and we analyzed acute care costs. For any patient the HAP has been calculated. The final value includes cost of hospital accommodation and management at the Pediatric and Infectious Diseases Unit. To this cost, the price of procedures (imaging, laboratory exams, medical and paramedical evaluations) and medical treatments was added. Results In the study period, 856 children had been hospitalized for varicella. Out of them, 65 met a diagnosis of AC and were included in the study. The hospitalization length was of 10 days (range 3-20 days). The median cost of HAP for each patient was of 5366 euro, with an average annual cost of 23,252 euro. The most significant part of HAP is due to the cost of hospital accommodation and management at the Pediatric Infectious Diseases Unit, which was about euro 537.78 for a single day. Discussion Although AC post-varicella is rare, its HAP cost is not negligible resulting in substantial economic burden. Vaccination would have probably prevented varicella and AC complication, avoiding hospitalization. Conclusions Financial studies are important for evaluate the cost saving in order to influence public funding decisions. Further studies are necessary to investigate the economic burden of the disease

Exploring the AGN-Merger Connection in Arp 245 I: Nuclear Star Formation and Gas Outflow in NGC 2992

Galaxy mergers are central to our understanding of galaxy formation, especially within the context of hierarchical models. Besides having a large impact on the star formation history, mergers are also able to influence gas motions at the centre of galaxies and trigger an Active Galactic Nucleus (AGN). In this paper, we present a case study of the Seyfert galaxy NGC 2992, which together with NGC 2993 forms the early-stage merger system Arp 245. Using Gemini Multi-Object Spectrograph (GMOS) integral field unit (IFU) data from the inner 1.1 kpc of the galaxy we were able to spatially resolve the stellar populations, the ionisation mechanism and kinematics of ionised gas. From full spectral synthesis, we found that the stellar population is primarily composed by old metal-rich stars (t $\geq$ 1.4 Gyr, $Z \geq 2.0$\zsun), with a contribution of at most 30 per cent of the light from a young and metal-poor population (t $\leq$ 100 Myr, $Z \leq 1.0$\zsun). We detect \halpha and \hbeta emission from the Broad Line Region (BLR) with a Full Width at Half Maximum (FWHM) of $\sim$ 2000\kms. The Narrow Line Region (NLR) kinematics presents two main components: one from gas orbiting the galaxy disk and a blueshifted (velocity $\approx$ -200\kms) outflow, possibly correlated with the radio emission, with mass outflow rate of $\sim$ 2 M$_{\odot}$ yr$^{-1}$ and a kinematic power of $\sim$ 2 $\times 10^{40}$ erg s$^{-1}$ (\Eout/\Lbol $\approx$ 0.2 per cent). We also show even though the main ionisation mechanism is the AGN radiation, ionisation by young stars and shocks may also contribute to the emission line ratios presented in the innermost region of the galaxy.Comment: 20 pages, 13 Figs, Accepted for publication to the MNRA

Respiratory Syncytial Virus Bronchiolitis in Infancy: The Acute Hospitalization Cost

Introduction: Respiratory syncytial virus (RSV) bronchiolitis is among the leading causes of hospitalization in infants. Prophylaxis with palivizumab may reduce RSV infection, but its prescription is restricted to high-risk groups. The aim of the study is to retrospectively determine acute hospitalization costs of bronchiolitis. Materials and methods: Infants aged 1 month-1 year, admitted to Bambino Gesu Children Hospital, Rome, Italy, with a diagnosis of bronchiolitis from January 1 till December 31, 2017, were included in the study. Results: A total of 531 patients were enrolled in the study, and the mean age was 78.75 days. The main etiologic agent causing bronchiolitis was RSV, accounting for 58.38% of infections. The total cost of bronchiolitis hospitalization was 2,958,786 euros. The mean cost per patient was significantly higher in the case of RSV (5,753.43 +/- 2,041.62 euros) compared to other etiology (5,395.15 +/- 2,040.87 euros) (p = 0.04). Discussion: The study confirms the high hospitalization cost associated with bronchiolitis. In detail, in the case of RSV etiology, the cost was higher compared to other etiology, which is likely due to the longer hospitalization and the more frequent admission to the intensive cure department. Conclusion: This study highlights that bronchiolitis is an important cost item even in a tertiary hospital and that cost-effective interventions targeting RSV are increasingly urgent

Live to die another day: the rebrightening of AT2018fyk as a repeating partial tidal disruption event

Stars that interact with supermassive black holes (SMBHs) can either be completely or partially destroyed by tides. In a partial tidal disruption event (TDE) the high-density core of the star remains intact, and the low-density, outer envelope of the star is stripped and feeds a luminous accretion episode. The TDE AT2018fyk, with an inferred black hole mass of $10^{7.7\pm0.4}$ M$_{\odot}$, experienced an extreme dimming event at X-ray (factor of $>$6000) and UV (factor $\sim$15) wavelengths $\sim$500--600 days after discovery. Here we report on the re-emergence of these emission components roughly 1200 days after discovery. We find that the source properties are similar to those of the pre-dimming accretion state, suggesting that the accretion flow was rejuvenated to a similar state. We propose that a repeating partial TDE, where the partially disrupted star is on a $\sim 1200$ day orbit about the SMBH and is periodically stripped of mass during each pericenter passage, powers its unique lightcurve. This scenario provides a plausible explanation for AT2018fyk's overall properties, including the rapid dimming event and the rebrightening at late times. We also provide testable predictions for the behavior of the accretion flow in the future: if the second encounter was also a partial disruption then we predict another strong dimming event around day 1800 (August 2023), and a subsequent rebrightening around day 2400 (March 2025). This source provides strong evidence of the partial disruption of a star by a SMBH.Comment: ApJ Letters, accepted for publicatio