Order reduction methods for solving large-scale differential matrix Riccati equations

We consider the numerical solution of large-scale symmetric differential matrix Riccati equations. Under certain hypotheses on the data, reduced order methods have recently arisen as a promising class of solution strategies, by forming low-rank approximations to the sought after solution at selected timesteps. We show that great computational and memory savings are obtained by a reduction process onto rational Krylov subspaces, as opposed to current approaches. By specifically addressing the solution of the reduced differential equation and reliable stopping criteria, we are able to obtain accurate final approximations at low memory and computational requirements. This is obtained by employing a two-phase strategy that separately enhances the accuracy of the algebraic approximation and the time integration. The new method allows us to numerically solve much larger problems than in the current literature. Numerical experiments on benchmark problems illustrate the effectiveness of the procedure with respect to existing solvers

Approximation of Optimal Control Problems for the Navier-Stokes equation via multilinear HJB-POD

We consider the approximation of some optimal control problems for the Navier-Stokes equation via a Dynamic Programming approach. These control problems arise in many industrial applications and are very challenging from the numerical point of view since the semi-discretization of the dynamics corresponds to an evolutive system of ordinary differential equations in very high dimension. The typical approach is based on the Pontryagin maximum principle and leads to a two point boundary value problem. Here we present a different approach based on the value function and the solution of a Bellman, a challenging problem in high dimension. We mitigate the curse of dimensionality via a recent multilinear approximation of the dynamics coupled with a dynamic programming scheme on a tree structure. We discuss several aspects related to the implementation of this new approach and we present some numerical examples to illustrate the results on classical control problems studied in the literature

Determinants of Cost to Client in Accessing Rural Financial Services – A Case of Zambia's Chongwe District

Providing affordable access to appropriate financial services for the low-income population has been an on-going challenge for most developing nations, Zambia included. On this premise, this paper seeks to empirically investigate and quantify costs to clients in accessing financial services in the rural areas of Zambia, based on cross-sectional primary data collected in the Chongwe district from 236 households, documentation and key informant interviews. This study used the Probit and Heckman selection models to analyse cost to the client factors affecting the likelihood of accessing financial services (credit) by rural households in Zambia. Results revealed that households’ costs incurred by clients in accessing financial services are not limited to financial costs such interest, fees, transport and savings, etc., but equally other hidden costs such regulatory and compliance costs, economic costs, psychological costs, and social and cultural costs. The study recommends that policy formulation in the areas of financial inclusion, rural and agricultural finance should be based on reducing cost-to-client attributes such as the regulatory and compliance costs, economic costs and psychological costs identified above. Keywords: costs to client, financial services, access to finance, Heckman two-stage model

Development of working memory from grade 3 to 5. Differences between children with and without mathematical learning difficulties

Based on the finding that children with mathematical learning difficulties (MLD) have deficits in working memory (WM), the question arises as to whether these children differ from typical learners only in the level or also in the developmental trajectories of WM functioning. To this end, the WM of 80 children with MLD and 71 typical learners was assessed longitudinally from third to fifth grade. Typical learners outperformed children with MLD in the phonological, visuospatial and central executive WM functioning in third grade. Latent change analyses indicated that both phonological and central executive WM functioning developed in a parallel pattern in children with MLD and in typical learners. In contrast, visuospatial WM functioning revealed a different development in children with and without MLD since the gap between both groups decreased over time. Overall, despite starting at a lower level, the WM functioning in children with MLD did not develop more slowly. (DIPF/Orig.

Okay, let's talk - short debriefings in the operating room

Introduction Debriefing is increasingly used to enhance learning and reflection in clinical practice. Nevertheless, barriers to implementing debriefings in the operating room (OR) include lack of time, the availability of trained facilitators, and difficulty gathering the full team after surgery. Spending five minutes on a debriefing during skin closure or between procedures may enhance learning and reflection on practice, generating to improve patient safety. The aim of this study was to explore characteristics, feasibility and content of short debriefings in the OR. Methods This was a mixed-method study of short debriefings, analyzing audio-recordings, field notes and relevance ratings from multi-professional teams, that conducted short debriefings in the OR at two University Hospitals in Denmark. Results A total of 135 debriefings were conducted, with a median duration of five minutes (range 1:19 min–12:05 min). A total of 477 team members participated in the debriefings. The teams’ median rating of relevance was 6 (range 1–10). The rating was higher following challenging events and in debriefings where the surgeon actively participated in the conversation. The teams discussed non-technical skills in all the debriefings and verbalized reflections on practice in 75 percent of the debriefings. Conclusion It was feasible to conduct short debriefings in a production-focused, complex work environment. In all the debriefings, the teams discussed various non-technical skills (NTS) and reflected on practice. The majority of team members rated the debriefings as relevant for their task management.publishedVersio

Mapping Nanomedicine Terminology in the Regulatory Landscape

A common terminology is essential in any field of science and technology for a mutual understanding among different communities of experts and regulators, harmonisation of policy actions, standardisation of quality procedures and experimental testing, and the communication to the general public. It also allows effective revision of information for policy making and optimises research fund allocation. In particular, in emerging scientific fields with a high innovation potential, new terms, descriptions and definitions are quickly generated, which are then ambiguously used by stakeholders having diverse interests, coming from different scientific disciplines and/or from various regions. The application of nanotechnology in health -often called nanomedicine- is considered as such emerging and multidisciplinary field with a growing interest of various communities. In order to support a better understanding of terms used in the regulatory domain, the Nanomedicines Working Group of the International Pharmaceutical Regulators Forum (IPRF) has prioritised the need to map, compile and discuss the currently used terminology of regulatory scientists coming from different geographic areas. The JRC has taken the lead to identify and compile frequently used terms in the field by using web crawling and text mining tools as well as the manual extraction of terms. Websites of 13 regulatory authorities and clinical trial registries globally involved in regulating nanomedicines have been crawled. The compilation and analysis of extracted terms demonstrated sectorial and geographical differences in the frequency and type of nanomedicine related terms used in a regulatory context. Finally 31 relevant and most frequently used terms deriving from various agencies have been compiled, discussed and analysed for their similarities and differences. These descriptions will support the development of harmonised use of terminology in the future. The report provides necessary background information to advance the discussion among stakeholders. It will strengthen activities aiming to develop harmonised standards in the field of nanomedicine, which is an essential factor to stimulate innovation and industrial competitiveness.JRC.F.2-Consumer Products Safet

The RESCueH Programme: Testing New Non-Pharmacologic Interventions for Alcohol Use Disorders

Excessive alcohol consumption is one of the most important lifestyle factors affecting the disease burden in the Western world. The results of treatment in daily practice are modest at best. The aim of the RESCueH programme is to develop and evaluate methods, which are as practice-near as possible, and therefore can be implemented quickly and easily in everyday clinical practice. It is the first clinical alcohol programme to be transatlantic in scope, with implementation in treatment centers located in Denmark, Germany and the US. The RESCueH programme comprises 5 randomized controlled trials, and the studies can be expected to result in (1) more patients starting treatment in specialized outpatient clinics, (2) a greater number of elderly patients being treated, (3) increased patient motivation for treatment and thus improved adherence, (4) more patients with stable positive outcomes after treatment and (5) fewer patients relapsing into harmful drinking. The aim of this paper is to discuss the rationale for the RESCueH programme, to present the studies and expected results