Context. The accretion history of low-mass young stars is not smooth but shows spikes of accretion that can last from months and years to decades and centuries. Aims. Observations of young stars in ...outbursts can help us understand the temporal evolution of accreting stars and the interplay between the accretion disk and the stellar magnetosphere. Methods. The young late-type star V1118 Orionis was in outburst from 2005 to 2006. We followed the outburst with optical and near-infrared photometry. The X-ray emission was further probed with observations taken with XMM-Newton and Chandra during and after the outburst. In addition, we obtained mid-infrared photometry and spectroscopy with Spitzer at the peak of the outburst and in the post-outburst phase. Results. The spectral energy distribution of V1118 Ori varied significantly over the course of the outburst. The optical flux showed the largest variations, most likely caused by enhanced emission by a hot spot. The hot spot dominated the optical and near-infrared emission at the peak of the outburst, while the disk emission dominated in the mid-infrared. The emission silicate feature in V1118 Ori is flat and does not vary in shape, but was slightly brighter at the peak of the outburst compared to the post-outburst spectrum. The X-ray flux correlated with the optical and infrared fluxes, indicating that accretion affected the magnetically active corona and the stellar magnetosphere. The thermal structure of the corona was variable with some indication of a cooling of the coronal temperature in the early phase of the outburst with a gradual return to normal values. Color–color diagrams in the optical and infrared showed variations during the outburst, with no obvious signature of reddening caused by circumstellar matter. Using Monte-Carlo realizations of star+disk+hotspot models to fit the spectral energy distributions in “quiescence” and at the peak of the outburst, we determined that the mass accretion rate varied from about $2.5 \times 10^{-7}$ $M_\odot$ yr-1 to $1.0 \times 10^{-6}$ $M_\odot$ yr-1; in addition, the fractional area of the hotspot increased significantly. Conclusions. The multi-wavelength study of the V1118 Ori outburst helped us to understand the variations in spectral energy distributions and demonstrated the interplay between the disk and the stellar magnetosphere in a young, strongly accreting star.
Context. Our knowledge of circumstellar disks has traditionally been based on studies of dust. However, gas dominates the disk mass and its study is key to our understanding of accretion, outflows, ...and ultimately planet formation. The Spitzer Space Telescope provides access to gas emission lines in the mid-infrared, providing crucial new diagnostics of the physical conditions in accretion disks and outflows. Aims. We seek to identify gas emission lines in mid-infrared spectra of 64 pre-main-sequence stars in Taurus. Using line luminosities and other known star-disk-outflow parameters, we aim to identify correlations that will help to constrain gas heating, excitation mechanisms, and the line formation. Methods. We have based our study on Spitzer observations using the Infrared Spectrograph (IRS), mainly with the high-resolution modules. Line luminosities (or 3σ upper limits) have been obtained by fitting Gaussian profiles to the lines. We have further searched for correlations between the line luminosities and different parameters related to the star-disk system. Results. We have detected H2 (17.03, 28.22 μm) emission in 6 objects, Ne II (12.81 μm) emission in 18 objects, and Fe II (17.93, 25.99 μm) emission in 7 objects. Ne II detections are found primarily in Class II objects. The luminosity of the Ne II line (LNeII) is in general higher for objects known to drive jets than for those without known jets, but the two groups are not statistically distinguishable. LNeII is correlated with X-ray luminosity, but for Class II objects only. LNeII is also correlated with disk mass and accretion rate when the sample is divided into high and low accretors. Furthermore, we find correlations of LNeII with mid-IR continuum luminosity and with luminosity of the O I (6300 Å) line, the latter being an outflow tracer. L FeII correlates with Ṁacc. No correlations were found between LH2 and several tested parameters. Conclusions. Our study reveals a general trend toward accretion-related phenomena as the origin of the gas emission lines. Shocks in jets and outflowing material are more likely to play a significant role than shocks in infalling material. The role of X-ray irradiation is less prominent but still present for Ne II, in particular for Class II sources, while the lack of correlation between Fe II and Ne II points toward different emitting mechanisms.
Abstract
Background
The worldwide prevalence of diabetes mellitus is increasing, which especially involves people aged >65 years. A recent study also found that almost 75% of adults with diabetes ...have two or more comorbid conditions. The aim of the study was to investigate the impact of comorbidities on health care service use and health care costs of an elderly diabetes cohort with high health care needs (HHCN), based on real-world data.
Methods
For the purposes of the present study, people with a diagnosis of diabetes, residing in the area served by the ex-ULSS4-Veneto LHU, and characterized as having HHCN, corresponding to ACG-RUBs 4 and 5 were considered. The comorbidities was assessed using clinical diagnoses that the ACG System assigns to single patients by combining different information flows. The presence of correlation between comorbidity classes and total annual health care costs and use was tested with Spearman Test. Moreover, the association between above mentioned variables was tested with a appropriate regression, adjusting for age and sex.
Results
Mean overall cost and drug cost ranged respectively from 6284 euro, 525 euro in a patient with only 1 comorbidity to 10752 euro and 1764 euro for a patient with more than 8 comorbidities. The study shows that all measures of health care services use (as emergency care accesses; number of outpatients visits; number of inpatients admissions) have a statistically significant correlation with comorbidities class. However, multivariate analyses revealed that no different use in hospitalization was associated with comorbidity class. A significant correlation was also detected among costs variables (total annual costs and pharmacy costs) and comorbidity classes.
Conclusions
The increase in total healthcare services use and costs due to the increased number of comorbidities was seen mainly for primary care services, highlighting the need of primary care to be strengthen in an ageing and multi-morbid population.
Key messages
Overall cost and drug cost for patients with more than 8 comorbidities are respectively almost doubled and more than threefold greater than those with only one comorbidities. The study revealed an increase in primary care services, suggesting an implementation of these services giving the aging population and the increase prevalence of comorbid diabetic patients worldwide.
Abstract The immunogenicity and reactogenicity of two influenza vaccines were evaluated in a randomised, double-blind trial in north-east Italy during winter 2005–2006. Of 238 adult subjects (18–60 ...years of age) with underlying chronic diseases, 120 received MF59-adjuvanted subunit vaccine (Sub/MF59) and 118 received conventional subunit vaccine (Subunit). At 4 weeks post-vaccination, geometric mean titres (GMT) were significantly ( P < 0.001) increased for both groups. For the A/H3N2 and B strains, significantly ( P < 0.02) higher GMT were reported for the Sub/MF59 group. The mean-fold increase in titre, the percentage of subjects with at least a four-fold titre increase and the seroprotection rate (≥1:40) were also higher in the Sub/MF59 group, with the seroprotection rate and four-fold titre increase achieving significance ( P = 0.002 and P = 0.02, respectively) for the A/H3N2 strain. Our results suggest that adults affected by chronic diseases can mount a satisfactory immune response to influenza vaccines, and that these vaccines are well tolerated. Addition of the MF59-adjuvant, however, enhances the immunogenicity of subunit influenza vaccine, conferring superior protection than a conventional subunit vaccine in this population, who are at high-risk of influenza-related complications.
Abstract
Vaccine hesitancy has been defined as the delay of acceptance or refusal of vaccines. Hesitant parents’ (HP) fluctuate between anti-vaccine (AP) and pro-vaccine parents’ (PP) positions. In ...the light of alarming results from recent Eurobarometer 488, our aim was to identify sensitive topics harbouring the widest opinion gap between HP and PP.
In 2017, an online questionnaire was administered to parents with children aged 3-84 months. Parents were classified as PP, HP or AP based on self-reported vaccine status and timeliness of vaccinations. Agreement with 25 items was assessed with 5-point Likert scale. Items were combined into 8 topics (benefit/risk of vaccines, trust/mistrust in healthcare workers, administration policies, complacency, sense of community, freedom of choice) and scores calculated. Internal consistency was evaluated with Cronbach’s α; t-tests (sig. <.05) were used (Norman G, 2018).
The study included 3,865 parents (64% PP; 32% HP; 4% AP). Cronbach’s α ranged 0.77-0.92. The widest gap concerned the sense of community: HP (2.7/5.0) cared significantly less than PP (4.7) about the usefulness of vaccine in protecting other children and claimed for a complete freedom in decision to vaccinate (3.6) more than PP (1.8). HP were worried (4.1) about current vaccination schedule (PP 2.1): simultaneous administration and age at vaccination (considered too young) were matter of concern. Among HP, mistrust of healthcare workers (3.7) and fear of side effects (3.8) played an important role, but the gap with PP was narrower compared with abovementioned topics; awareness in vaccine benefits reached 3.7. Agreement with complacent attitudes was low (2.2) with the least difference with PP (1.2).
HP showed to partially consider benefits of vaccines on a community scale, claiming for a private nature of this choice. The existence of a consistent opinion gap about the vaccination schedule may suggest the need for a sharper focus on current communication tools and strategies.
Key messages
While hesitant parents share some concerns with pro-vaccine, relevant opinion gaps may serve as warning lights, pointing at topics potentially harbouring the most sensitive drivers of hesitancy.
Communication strategies should primarily focus on raising acquaintance of hesitant parents with benefits arising from herd immunity and compliance with the suggested vaccination schedule.
Abstract
Vaccine hesitancy is a growing concern in many European countries, including Italy, as instanced by alarming results from Eurobarometer 488 dated April 2019. In the view of the current ...magnitude of the phenomenon, our aim was to investigate its determinants among parents, with a specific view on those working as health professional.
In 2017, parents of children aged 3-84 months were recruited online. Based on self-reported vaccine status and timeliness of vaccinations, parents were classified as pro-, hesitant, or anti-vaccine. The association between baseline characteristics and hesitancy was investigated with logistic regression adjusting for child’s and parents’ age, prematurity, presence of older children, previous vaccine adverse reaction in the child at issue, parents’ nationality, education and employment status, health profession of at least one parent, single parenting, vegetarian lifestyle and perceived economic security.
A total of 3,865 questionnaires were collected (64% pro-, 32% hesitant, 4% anti-vaccine). Families with at least one health professional as parent were 20% of the sample.
Vegetarian lifestyle (aOR 3.0; 95%CI 2.20-4.08), unsatisfactory (aOR 1.67 95%CI 1.08-2.58) and partially satisfactory perceived economic security (aOR 1.40; 95%CI 1.09-1.78) and previous vaccine adverse reactions (aOR 1.25; 95%CI 1.05-1.48) were associated with vaccine hesitancy, while having older children resulted as a protective factor (aOR 0.82; 95%CI 0.69-0.98). No significant association was found with other abovementioned variables, including parent employed as health professional (aOR 0.99; 95%CI 0.81-1.22).
Vaccine hesitancy seems to be part of a lifestyle choice and, to a smaller extent, associated with previous vaccine adverse reactions and lower socioeconomic status. Interestingly, parents’ level of education and employment in healthcare do not affect vaccine acceptance. The latter poses a challenge, given their crucial role in promoting vaccination.
Key messages
Hesitancy is associated with lifestyle choices, experience of adverse reactions and socioeconomic status, while education and employment as health professional seem not to be relevant.
Whether they are health professionals or not, parents’ attitude towards their child’s vaccinations is the same.
Regarding the intraday sequence of high-frequency returns of the S&P index as daily realizations of a given stochastic process, we first demonstrate that the scaling properties of the aggregated ...return distribution can be employed to define a martingale stochastic model which consistently replicates conditional expectations of the S&P 500 high-frequency data in the morning of each trading day. Then, a more general formulation of the above scaling properties allows to extend the model to the afternoon trading session. We finally outline an application in which conditioned forecasting is used to implement a trend-following trading strategy capable of exploiting linear correlations present in the S&P data-set and absent in the model. Trading signals are model based and not derived from chartist criteria. In-sample and out-of-sample tests indicate that the model-based trading strategy performs better than a benchmark one established on an asymmetric GARCH process, and show the existence of small arbitrage opportunities. We remark that in the absence of linear correlations the trading profit would vanish and discuss why the trading strategy is potentially interesting to hedge volatility risk for S&P index-based products.
PDF
