BENCHOP–SLV: the BENCHmarking project in Option Pricing–Stochastic and Local Volatility problems

In the recent project BENCHOP–the BENCHmarking project in Option Pricing we found that Stochastic and Local Volatility problems were particularly challenging. Here we continue the effort by introducing a set of benchmark problems for this type of problems. Eight different methods targeted for the Stochastic Differential Equation (SDE) formulation and the Partial Differential Equation (PDE) formulation of the problem, as well as Fourier methods making use of the characteristic function, were implemented to solve these problems. Comparisons are made with respect to time to reach a certain error level in the computed solution for the different methods. The implemented Fourier method was superior to all others for the two problems where it was implemented. Generally, methods targeting the PDE formulation of the problem outperformed the methods for the SDE formulation. Among the methods for the PDE formulation the ADI method stood out as the best performing one

Predicting discharge location of hip fracture patients; the new discharge of hip fracture patients score

Purpose This paper reports on the development and validity of a new instrument, called the discharge of hip fracture patients score (DHP), that predicts at admission the discharge location in patients living in their own home prior to hip fracture surgery. Methods A total of 310 patients aged 50 years and above were included. Risk factors for discharge to an alternative location (DAL) were analysed with a multivariable regression analysis taking the admission variables into account with different weights based on the estimates. The score ranged from 0-100 points. The cut-off point for DAL was calculated using a ROC analysis. Reliability of the DHP was evaluated. Results Risk factors for DAL were higher age, female gender, dementia, absence of a partner and a limited level of mobility. The cut-off point was set at 30 points, with a sensitivity of 83.8%, a specificity of 64.7% and positive predictive value of 79.2%. Conclusion The DHP is a valid, simple and short instrument to be used at admission to predict discharge location of hip fracture patients

Risk factors for failure to return to the pre-fracture place of residence after hip fracture: a prospective longitudinal study of 444 patients

Introduction: Long-term place of residence after hip fracture is not often described in literature. The goal of this study was to identify risk factors, known at admission, for failure to return to the pre-fracture place of residence of hip fracture patients in the Wrst year after a hip fracture. Methods: This is a prospective longitudinal study of 444 consecutive admissions of hip fracture patients aged ≥65 years. Place of residence prior to admission, at discharge, after 3 and 12 months was registered. Patients admitted from a nursing home (n = 49) were excluded from statistical analysis. Multivariable logistic regression analysis was performed, using age, gender, presence of a partner, ASAscore, dementia, anaemia at admission, type of fracture, pre-fracture level of mobility and level of activities of daily living (ADL) as possible risk factors. Results: Two hundred eighty-nine patients lived in their own home, 31.8% returned at discharge, 72.9% at 3 months and 72.8% at 12 months. Age, absence of a partner, dementia, and a lower pre-fracture level of ADL or mobility were independent contributors to failure to return to their own home at discharge, 3 or 12 months. 106 patients lived in a residential home; 33.3% returned at discharge, 68.4% at 3 months and 64.4% at 12 months. Age was an independent contributor to failure to return to a residential home. Conclusions: Age, dementia and a lower pre-fracture level of ADL were the main signiWcant risk factors for failure to return to the pre-fracture residence. As the 3- and 12-month return-rates were similar, 3-month follow-up might be used as an endpoint in future research

Understanding private law. On the work of Hans Nieuwenhuis, 1944-2015

Hans Nieuwenhuis’ work is difficult to capture in a single sentence. It aims to impart an understanding of private law which, Nieuwenhuis says, requires an awareness of time, space and balance. We measure his work by his own yardstick.Coherent privaatrech

The handbook for standardized field and laboratory measurements in terrestrial climate change experiments and observational studies (ClimEx)

Climate change is a world-wide threat to biodiversity and ecosystem structure, functioning and services. To understand the underlying drivers and mechanisms, and to predict the consequences for nature and people, we urgently need better understanding of the direction and magnitude of climate change impacts across the soil-plant-atmosphere continuum. An increasing number of climate change studies are creating new opportunities for meaningful and high-quality generalizations and improved process understanding. However, significant challenges exist related to data availability and/or compatibility across studies, compromising opportunities for data re-use, synthesis and upscaling. Many of these challenges relate to a lack of an established 'best practice' for measuring key impacts and responses. This restrains our current understanding of complex processes and mechanisms in terrestrial ecosystems related to climate change. To overcome these challenges, we collected best-practice methods emerging from major ecological research networks and experiments, as synthesized by 115 experts from across a wide range of scientific disciplines. Our handbook contains guidance on the selection of response variables for different purposes, protocols for standardized measurements of 66 such response variables and advice on data management. Specifically, we recommend a minimum subset of variables that should be collected in all climate change studies to allow data re-use and synthesis, and give guidance on additional variables critical for different types of synthesis and upscaling. The goal of this community effort is to facilitate awareness of the importance and broader application of standardized methods to promote data re-use, availability, compatibility and transparency. We envision improved research practices that will increase returns on investments in individual research projects, facilitate second-order research outputs and create opportunities for collaboration across scientific communities. Ultimately, this should significantly improve the quality and impact of the science, which is required to fulfil society's needs in a changing world.Peer reviewe

The Epidemic of Hip Fractures: Are We on the Right Track?

Background: Hip fractures are a public health problem, leading to hospitalization, long-term rehabilitation, reduced quality of life, large healthcare expenses, and a high 1-year mortality. Especially older adults are at greater risk of fractures than the general population, due to the combination of an increased fall risk and osteoporosis. The aim of this study was to determine time trends in numbers and incidence rates of hip fracture-related hospitalizations and admission duration in the older Dutch population. Methods and Findings: Secular trend analysis of all hospitalizations in the older Dutch population (≥65 years) from 1981 throughout 2008, using the National Hospital Discharge Registry. Numbers, age-specific and age-adjusted incidence rates (per 10,000 persons) of hospital admissions and hospital days due to a hip fracture were used as outcome measures in each year of the study. Between 1981 and 2008, the absolute number of hip fractures doubled in the older Dutch population. Incidence rates of hip fracture-related hospital admissions increased with age, and were higher in women than in men. The age-adjusted incidence rate increased from 52.0 to 67.6 per 10,000 older persons. However, since 1994 the incidence rate decreased (percentage annual change -0.5%, 95% CI: -0.7; -0.3), compared with the period 1981-1993 (percentage annual change 2.3%, 95% CI: 2.0; 2.7). The total number of hospital days was reduced by a fifth, due to a reduced admission duration in all age groups. A possible limitation was that data were obtained from a linked administrative database, which did not include information on medication use or co-morbidities. Conclusions: A trend break in the incidence rates of hip fracture-related hospitalizations was observed in the Netherlands around 1994, possibly as a first result of efforts to prevent falls and fractures. However, the true cause of the observation is unknown

Clinical and biochemical prediction of early fatal outcome following hip fracture in the elderly

Hip fracture, a moderate musculoskeletal trauma, is associated with a high postoperative mortality. Most patients are elderly, with comorbid conditions and often with heart disease. The objective of this study was to find out if clinical parameters and analyses of specific muscle enzymes could predict three month postoperative mortality. A total of 302 patients above 75 years of age with hip fracture were consecutively enrolled. Baseline information on age, sex and comorbidity assessed with the American Society of Anesthesiologists (ASA) score was obtained before surgery. Creatine kinase (CK), myocardium-specific creatine kinase (CK-MB) and troponin T (TnT) were analysed from venous blood, collected the day before surgery (−1) and postoperatively, within 24 hours (0) and on days one (+1) and four (+4). The overall three month mortality was 19.5%. Multivariate analyses showed that age, male sex and comorbidity (ASA) correlated with mortality (p = 0.027, p = 0.002, p < 0.001, respectively). Surgery induced a two- to threefold increase of CK and CK-MB but without any correlation with mortality. However, high TnT levels >0.04 μg/l correlated significantly with death (days −1, +1 and +4, p = 0.003, p = 0.005 and p = 0.003, respectively). Multivariate analyses, adjusted for age, sex and ASA category, confirmed this correlation (day +4, p = 0.008). Thus, in elderly patients with comorbidities undergoing hip fracture surgery information on sex, age, ASA category and postoperative laboratory analyses on TnT provide the clinicians with useful information on patients at risk of fatal outcome