2,669 research outputs found
Mixed-frequency quantile regression with realized volatility to forecast Value-at-Risk
The use of quantile regression to calculate risk measures has been widely
recognized in the financial econometrics literature. When data are observed at
mixed-frequency, the standard quantile regression models are no longer
adequate. In this paper, we develop a model built on a mixed-frequency quantile
regression to directly estimate the Value-at-Risk. In particular, the
low-frequency component incorporates information coming from variables observed
at, typically, monthly or lower frequencies, while the high-frequency component
can include a variety of daily variables, like realized volatility measures or
market indices. We derive the conditions for the weak stationarity of the daily
return process suggested while the finite sample properties are investigated in
an extensive Monte Carlo exercise. The validity of the proposed model is then
explored through a real data application using the most important financial
indexes. We show that our model outperforms other competing specifications,
using backtesting and Model Confidence Set procedures
“The Theater of the Mind”: The Effect of Radio Exposure on TV Advertising
Contemporary society requires communication strategies that integrate different media channels in order to improve advertising performance. Currently, there are not many scientific research studies of the various mass media, comparing the results of audiovisual advertising to purely audio or visual messages aimed at detecting the best combination of media, especially from a neurophysiological perspective. This study aims to investigate the effects of previous exposure to an advertisement via radio on the consumers’ response to the same advertisement shown on television (TV) or as a banner on a website. A total of seventy participants in a between-subjects experiment watched several television commercials during the advertising break of a documentary or saw some banners during a web surfing task. Half were first exposed to the same advertisements via radio. The results have shown that participants who previously listened to the radio advertisements spent a longer time looking at the brand and had a higher engagement when watching the same advertisements on television. Moreover, they had a different kind of visual attention to the website banners. This pattern of results indicates the effect of mere exposure—that is, the exposure to a radio advertisement enhances the effectiveness of the same advertisement via television or web, offering useful insights for media planning campaigns. Even if mere exposure has been extensively studied, cross-media research is scarcely explored, whereas this study detected the effects of mere exposure in a cross-media communication strategy, showing that it can be measured through psychophysiological methods
Impact of pneumococcal conjugate vaccination: a retrospective study of hospitalization for pneumonia in North-East Italy
Introduction. Pneumonia remains a common reason for hospitalizing
infants and the elderly worldwide, and streptococcal infection
is often responsible. The aim of this study was to assess the
burden of pneumonia in a large general population.
Methods. All pneumonia-related hospitalizations from 2004 to
2013 in north-east Italy were identified from the hospital records
with a first-listed diagnosis on discharge of bacterial pneumonia,
or a first-listed diagnosis on discharge of meningitis, septicemia
or empyema associated with a secondary diagnosis of bacterial
pneumonia. We identified major comorbidities, calculated agespecific
case-fatality rates (CFR), and estimated the related cost
to the health care system.
Results. Of the 125,722 hospitalizations identified, 96.9% were
cases of pneumonia, 2.4% of septicemia, 0.4% of meningitis, and
0.3% of empyema; 75.3% of hospitalizations involved 65 65-yearolds.
The overall CFR was 12.4%, and it increased with age,
peaking in people over 80 (19.6%).
The mean annual pneumonia-associated hospitalization rate was
204.6 per 100,000 population, and it peaked in 0- to 4-year-old children
(325.6 per 100,000 in males, 288.9 per 100,000 in females),
and adults over 65 (844.9 per 100,000 in males, 605.7 per 100,000
in females).
Hospitalization rates dropped over the years for the 0-4 year-olds,
and rose for people over 80. The estimated overall annual cost of
these pneumonia-related hospitalizations was approximately \u20ac 41
million.
Conclusions. This study shows that the burden on resources for
pneumonia-related hospitalization is an important public health
issue. Prevention remains the most valuable tool for containing pneumonia,
and vaccination strategies can help in the primary prevention
of infection, possibly reducing the number of cases in all age groups
Nonischemic Donor Heart Preservation: New Milestone in Heart Transplantation History
Heart transplantation is considered the gold standard for the treatment of advanced end-stage heart failure. However, standard donors after brain death are decreasing, whereas patients on the heart transplant waitlist are constantly rising. The introduction of the ex vivo machine perfusion device has been a turning point; in fact, these systems are able to significantly reduce ischemic times and have a potential effect on ischemia-related damage reduction. From a clinical standpoint, these machines show emerging results in terms of heart donor pool expansion, making marginal donors and donor grafts after circulatory death suitable for donation. This article aims to review mechanisms and preclinical and clinical outcomes of currently available ex vivo perfusion systems, and to explore the future fields of application of these technologies
Evolution of Surgical Management of Hemorrhoidal Disease: An Historical Overview
Enfermedad hemorroidal; Terapias quirĂşrgicasMalaltia hemorroidal; TerĂ pies quirĂşrgiquesHemorrhoidal disease; Surgical therapiesHemorrhoidal disease (HD) is the symptomatic enlargement and/or distal displacement of the normal hemorrhoidal cushions and is one of the most frequent diseases in colorectal surgery. Several surgical or office-based therapies are currently available, with the aim of being a more tailored approach. This article aimed to elucidate the historical evolution of surgical therapy for HD from ancient times, highlighting the crucial steps, controversies, and pioneers in the field. In contrast with the previous literature on the topic that is often updated to the 1990s, with the introduction of stapled hemorrhoidopexy and transanal hemorrhoidal dearterialization, this article describes all new surgical and office-based treatments introduced in the first 20 years of the 2000s
Mesenchymal Stromal Cell Therapy in the Management of Perianal Fistulas in Crohn’s Disease. An Up-To-Date Review
Crohn's Disease (CD) is a chronic inflammatory disorder that potentially involves the entire gastrointestinal tract. Perianal fistulizing CD (pCD) is a serious and frequent complication associated with significant morbidities and a heavy negative impact on quality of life. The aim of CD treatment is to induce and maintain disease remission and to promote mucosal repair. Unfortunately, even the best therapeutic regimens in pCD do not have long-term efficacy and cause a significant number of side effects. Therefore, it is mandatory to study new therapeutical options such as the use of mesenchymal stromal cells (MSCs). These cells promote tissue repair via the induction of immunomodulation. The present review aims to analyze the existing updated scientific literature on MSCs adoption in the treatment of pCD to evaluate its efficacy and safety and to compare the use of bone marrow and adipose tissue derived MSCs, type of administration, and dose required for recovery
Drift-Aware Methodology for Anomaly Detection in Smart Grid
Energy efficiency and sustainability are important factors to address in the context of smart cities. In this sense, smart metering and nonintrusive load monitoring play a crucial role in fighting energy thefts and for optimizing the energy consumption of the home, building, city, and so forth. The estimated number of smart meters will exceed 800 million by 2020. By providing near real-time data about power consumption, smart meters can be used to analyze electricity usage trends and to point out anomalies guaranteeing companies' safety and avoiding energy wastes. In literature, there are many proposals approaching the problem of anomaly detection. Most of them are limited because they lack context and time awareness and the false positive rate is affected by the change in consumer habits. This research work focuses on the need to define anomaly detection method capable of facing the concept drift, for instance, family structure changes; a house becomes a second residence, and so forth. The proposed methodology adopts long short term memory network in order to profile and forecast the consumers' behavior based on their recent past consumptions. The continuous monitoring of the consumption prediction errors allows us to distinguish between possible anomalies and changes (drifts) in normal behavior that correspond to different error motifs. The experimental results demonstrate the suitability of the proposed framework by pointing out an anomaly in a near real-time after a training period of one week
Off-Adherence Keeping (OAK) observational study: intentional off-adherence immunomodulatory multiple sclerosis treatment
Aims: To evaluate how improved treatment adherence with a lower-frequency regimen/treatment of intramuscular (IM) IFN beta-1a impacts therapeutic effectiveness in relapsing-remitting multiple sclerosis (MS) patients switching from a higher-frequency injectable regimen/treatment. Patients & methods: Italian patients with relapsing-remitting MS and prior poor adherence to high-frequency injectable treatments (n = 181) were followed for 24 months after starting IM IFN beta-1a. Results: During the study, 97.4% of patients were treatment adherent; 22.1% of patients reported a relapse. The estimated probability of remaining relapse-free after 2 years was 78%. A high dropout rate (52.5%) led to small sample size and reduced statistical power. Conclusion: Intramuscular IFN beta-1a treatment was associated with high adherence and a low relapse rate. Unfortunately, low patient retention limited the generalizability of these findings.Plain language summary: Prior research suggests that taking the drug IFN beta-1a through less frequent muscle injections enables more patients to adhere to their prescription than taking other medications. This study included 181 Italian patients with relapsing-remitting multiple sclerosis (MS) who historically did not take medication as often as prescribed. Relapses of MS were counted among patients treated with muscle injections of IFN beta-1a for 2 years; 97.4% of patients followed their prescription and 22.1% experienced a relapse. From these data, 78% of patients were estimated not to experience a relapse during 2 years of IFN beta-1a muscle injections. However, an unusually high number of patients (52.5%) left the study within 2 years, which makes it difficult to draw firm conclusions
- …