2,121 research outputs found

    Neural Networks for quantile claim amount estimation: aq auntile regression approach

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    In this paper, we discuss the estimation of conditional quantiles of aggregate claim amounts for non-life insurance embedding the problem in a quantile regression framework using the neural network approach. As the first step, we consider the quantile regression neural networks (QRNN) procedure to compute quantiles for the insurance ratemaking framework. As the second step, we propose a new quantile regression combined actuarial neural network (Quantile-CANN) combining the traditional quantile regression approach with a QRNN. In both cases, we adopt a two-partmodel scheme where we fit a logistic regression to estimate the probability of positive claims and the QRNN model or the Quantile-CANN for the positive outcomes. Through a case study based on a health insurance dataset, we highlight the overall better performances of the proposed models with respect to the classical quantile regression one. We then use the estimated quantiles to calculate a loaded premium following the quantile premium principle, showing that the proposed models provide a better risk differentiation

    Novel platinum agents and mesenchymal stromal cells for thoracic malignancies : state of the art and future perspectives

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    Introduction: Non-small cell lung cancer and malignant pleural mesothelioma represent two of the most intriguing and scrutinized thoracic malignancies, presenting interesting perspectives of experimental development and clinical applications. Areas covered: In advanced non-small cell lung cancer, molecular targeted therapy is the standard firstline treatment for patients with identified driver mutations; on the other hand, chemotherapy is the standard treatment for patients without EGFR mutations or ALK rearrangement or those with unknown mutation status. Once considered an ineffective therapy in pulmonary neoplasms, immunotherapy has been now established as one of the most promising therapeutic options. Mesenchymal stromal cells are able to migrate specifically toward solid neoplasms and their metastatic localizations when injected intravenously. This peculiar cancer tropism has opened up an emerging field to use them as vectors to deliver antineoplastic drugs for targeted therapies. Expert opinion: Molecular targeted therapy and immunotherapy are the new alternatives to standard chemotherapy. Mesenchymal stromal cells are a new promising tool in oncology and\u2014although not yet utilized in the clinical practice, we think they will represent another main tool for cancer therapy and will probably play a leading role in the field of nanovectors and molecular medicine

    The Physical Activity–Related Barriers and Facilitators Perceived by Men Living in Rural Communities

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    Men, especially those living in rural areas, experience chronic disease at higher rates than the general population. Physical activity is a well-established protective factor against many chronic diseases; however, only a small fraction of men are meeting national guidelines for physical activity. The purpose of this study was to examine the perceived physical activity–related barriers and facilitators experienced by men living in rural areas in Canada. Participants completed a paper-and-pencil or online survey and asked to select personally relevant physical activity-related barriers and facilitators from a list of 9 and 10 choices, respectively. A total of 149 men completed the survey (50.3% between the ages of 18 and 55 years; 43.0% older than 55 years). Participants were predominantly from rural areas and smaller communities. Overall, the response options “I’m too tired,” “I don’t have enough time,” and “I think I get enough exercise as work” were the three most frequently cited barriers to regular physical activity. The response options “Personal motivation to be healthy,” “I enjoy it,” and “Support from family and/or friends” were the three most often cited facilitators to physical activity. Results are similar to those shown in other populations. Results can be used to inform the development of policies and programs that aim to increase the physical activity levels of men living in rural areas and small communities

    Factor demand linkages, technology shocks, and the business cycle

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    This paper argues that factor demand linkages can be important for the transmission of both sectoral and aggregate shocks. We show this using a panel of highly disaggregated manufacturing sectors together with sectoral structural VARs. When sectoral interactions are explicitly accounted for, a contemporaneous technology shock to all manufacturing sectors implies a positive response in both output and hours at the aggregate level. Otherwise there is a negative correlation, as in much of the existing literature. Furthermore, we find that technology shocks are important drivers of the business cycle

    Central Versus Peripheral Cardiovascular Risk in Metabolic Syndrome

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    Individuals with metabolic syndrome (MetS; i.e., three of five of the following risk factors (RFs): elevated blood pressure, waist circumference, triglycerides, blood glucose, or reduced HDL) are thought to be prone to serious cardiovascular disease and there is debate as to whether the disease begins in the peripheral vasculature or centrally. This study investigates hemodynamics, cardiac function/morphology, and mechanical properties of the central (heart, carotid artery) or peripheral [total peripheral resistance (TPR), forearm vascular bed] vasculature in individuals without (1–2 RFs: n = 28), or with (≥3 RFs: n = 46) MetS. After adjustments for statin and blood pressure medication use, those with MetS had lower mitral valve E/A ratios (<3 RFs: 1.24 ± 0.07; ≥3 RFs: 1.01 ± 0.04; P = 0.025), and higher TPR index (<3 RFs: 48 ± 2 mmHg/L/min/m2; ≥3 RFs: 53 ± 2 mmHg/L/min/m2; P = 0.04). There were no differences in heart size, carotid artery measurements, cardiovagal baroreflex, pulse-wave velocity, stroke volume index, or cardiac output index due to MetS after adjustments for statin and blood pressure medication use. The use of statins was associated with increased inertia in the brachial vascular bed, increased HbA1c and decreased LDL cholesterol. The independent use of anti-hypertensive medication was associated with decreased predicted VO2max, triglycerides, diastolic blood pressure, interventricular septum thickness, calculated left ventricle mass, left ventricle posterior wall thickness, and left ventricle pre-ejection period, but increased carotid stiffness, HDL cholesterol, and heart rate. These data imply that both a central cardiac effect and a peripheral effect of vascular resistance are expressed in MetS. These data also indicate that variance in between-group responses due to pharmacological treatments are important factors to consider in studying cardiovascular changes in these individuals

    Investigational Paradigms in Downscoring and Upscoring DCIS: Surgical Management Review

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    Counseling patients with DCIS in a rational manner can be extremely difficult when the range of treatment criteria results in diverse and confusing clinical recommendations. Surgeons need tools that quantify measurable prognostic factors to be used in conjunction with clinical experience for the complex decision-making process. Combination of statistically significant tumor recurrence predictors and lesion parameters obtained after initial excision suggests that patients with DCIS can be stratified into specific subsets allowing a scientifically based discussion. The goal is to choose the treatment regimen that will significantly benefit each patient group without subjecting the patients to unnecessary risks. Exploring the effectiveness of complete excision may offer a starting place in a new way of reasoning and conceiving surgical modalities in terms of “downscoring” or “upscoring” patient risk, perhaps changing clinical approach. Reexcison may lower the specific subsets' score and improve local recurrence-free survival also by revealing a larger tumor size, a higher nuclear grade, or an involved margin and so suggesting the best management. It seems, that the key could be identifying significant relapse predictive factors, according to validated risk investigation models, whose value is modifiable by the surgical approach which avails of different diagnostic and therapeutic potentials to be optimal. Certainly DCIS clinical question cannot have a single curative mode due to heterogeneity of pathological lesions and histologic classification

    Barriers to recruiting men into chronic disease prevention and management programs in rural areas: Perspectives of program delivery staff

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    Chronic disease is becoming increasingly prevalent in Canada. Many of these diseases could be prevented by adoption of healthy lifestyle habits including physical activity and healthy eating. Men, especially those in rural areas, are disproportionately affected by chronic disease. However, men are often underrepresented in community-based chronic disease prevention and management (CDPM) programs, including those that focus on physical activity and/or healthy eating. The purpose of this study was to explore the experiences and perceptions of program delivery staff regarding the challenges in recruitment and participation of men in physical activity and healthy eating programs in rural communities, and suggestions for improvement. Semistructured interviews were conducted by telephone with 10 CDPM program delivery staff from rural communities in Southwest Ontario, Canada. Time and travel constraints, relying on spouses, and lack of male program leaders were cited as barriers that contributed to low participation levels by men in CDPM programs. Hiring qualified male instructors and engaging spouses were offered as strategies to increase men’s participation. The results of this study highlight many of the current issues faced by rural health organizations when offering CDPM programming to men. Health care organizations and program delivery staff can use the recommendations in this report to improve male participation levels

    Liver contrast enhanced ultrasound perfusion imaging in the evaluation of chronic hepatitis C fibrosis: preliminary results

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    We wanted to determine whether liver contrast-enhanced ultrasound (CEUS)–derived peak signal intensity (PSI) and peak signal intensity/time (PIT) predict liver fibrosis in chronic hepatitis C (CHC). Fortynine patients with CHC (METAVIR classification) and 10 control subjects were included in the study. After a bolus of 2.4 mL SonoVue (Bracco Imaging, Milan, Italy) solution was injected into a peripheral vein, the right lobe of the liver containing the right portal vein was scanned in a transverse section. Two-dimensional sonography was performed using the Philips iU22 ultrasound system (Philips Healthcare, Best, the Netherlands). A 1.0–5.0-MHz (C5-1) wideband convex transducer was used, applying the following settings in all cases. Regions of interest were manually drawn over the right liver lobe and over the portal vein (PV). Liver parenchyma PSI (LPpsi) and PIT (LPpit), portal vein PSI (PVpsi) and PIT (PVpit) were automatically calculated. dPSI was defined as the difference between PVpsi and LPpsi. A significant correlation was observed between PAPSI and fibrosis scores. When patients were stratified according to their LPpsi, a significant difference was achieved only between patients with fibrosis score 0–1 vs. 2–3 and 2 vs. 4. Statistically significant differences between all fibrosis scores, except 0 vs. 1 and 3 vs. 4 were observed when dPSI was used to stratify patients. Overall diagnostic accuracy of LPpsi and dPSI measurement for severe fibrosis by area under the receiving operator characteristic curve analysis was, respectively, 0.87 and 0.88.We suggest that liver CEUS perfusion could have the potential to be used as a complementary tool for the evaluation of liver fibrosis. However, further large-scale studies are required to accurately assess its accuracy in the evaluation of liver fibrosis

    A new sustainable and innovative work for paper artworks cleaning process: Gellan hydrogel combined with hydrolytic enzymes

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    Paper has been used as writing and drawing support for thousands of years. The conservation of paper artworks plays a fundamental role in the field of our cultural heritage. Moreover, restoration of paper artworks is difficult due to their inherent fragility, the presence of many components and their degradation state. Among the factors that may contribute to paper deterioration are the use of glue for the application of different materials (as a lining, mounting or as a repair intervention) on the paper artifact. During a natural ageing process, glue become yellow, acid and less compact, accelerating the degradation processes of the artwork itself. The removal of glues from paper artworks represents, therefore, an important procedure for their preservation. Here we present a sustainable alternative to the common removal systems (e.g. solvents or localized enzymatic packs on the support to be cleaned). For this goal we used a rigid Gellan hydrogel (totally removable in one step) containing hydrolytic enzyme, such as proteinase K. The enzyme works as a selective cleaning agent hydrolyzing animal glues into smaller fragments, soluble into the gel. Our system represents an effective alternative to the traditional techniques because it is easy to be prepared, eco-friendly and efficient

    Autoimmune polyendocrine syndromes in the pediatric age

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    Autoimmune polyendocrine syndromes (APSs) encompass a heterogeneous group of rare diseases characterized by autoimmune activity against two or more endocrine or non-endocrine organs. Three types of APSs are reported, including both monogenic and multifactorial, heterogeneous disorders. The aim of this manuscript is to present the main clinical and epidemiological characteristics of APS-1, APS-2, and IPEX syndrome in the pediatric age, describing the mechanisms of autoimmunity and the currently available treatments for these rare conditions
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