2,513 research outputs found
Neural Networks for quantile claim amount estimation: aq auntile regression approach
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
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
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
Central Versus Peripheral Cardiovascular Risk in Metabolic Syndrome
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
Factor demand linkages, technology shocks, and the business cycle
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
Investigational Paradigms in Downscoring and Upscoring DCIS: Surgical Management Review
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
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
Device and method for converting direct current into alternate current
The device for converting direct current into alternate current comprises a multilevel converter associated with at least a source of direct current and a modulation unit having piloting means for piloting the converter for the conversion of the direct current into an alternate output current, in which the modulation unit comprises comparison means for comparing the output current value with a preset positive threshold value and a preset negative threshold value, the piloting means being suitable for piloting the converter with a pulse modulation of the unipolar type in the event of the output current value being above the positive threshold value or below the negative threshold value and with a pulse modulation of the complementary type in the event of the output current value being below the positive threshold value and above the negative threshold value. The method for converting direct current into alternate current comprises a piloting phase of a multilevel converter for the conversion of a direct voltage into an alternate output voltage, a comparison phase of the output current value with a preset positive threshold value and a preset negative threshold value, the piloting phase being suitable for piloting the converter with a pulse modulation of the unipolar type in the event of the output current value being above the positive threshold value or below the negative threshold value and with a pulse modulation of the complementary type in the event of the output current value being below the positive threshold value and above the negative threshold value
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