Investigating the relationships between peristaltic contraction and fluid transport in the human colon using Smoothed Particle Hydrodynamics

© 2012. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Complex relationships exist between gut contractility and the flow of digesta. We propose here a Smoothed Particle Hydrodynamics model coupling the flow of luminal content and wall flexure to help investigate these relationships. The model indicates that a zone of muscular relaxation preceding the contraction is an important element for transport. Low pressures in this zone generate positive thrust for low viscosity content. The viscosity of luminal content controls the localization of the flow and the magnitude of the radial pressure gradient and together with contraction amplitude they control the transport rate. For high viscosity content, high lumen occlusion is required for effective propulsion

GPs' perspectives on the management of patients with multimorbidity: systematic review and synthesis of qualitative research.

OBJECTIVE: To synthesise the existing published literature on the perceptions of general practitioners (GPs) or their equivalent on the clinical management of multimorbidity and determine targets for future research that aims to improve clinical care in multimorbidity. DESIGN: Systematic review and metaethnographic synthesis of primary studies that used qualitative methods to explore GPs' experiences of clinical management of multimorbidity or multiple chronic diseases. DATA SOURCES: EMBASE, MEDLINE, CINAHL, PsycInfo, Academic Search Complete, SocIndex, Social Science Full Text and digital theses/online libraries (database inception to September 2012) to identify literature using qualitative methods (focus groups or interviews). REVIEW METHODS: The 7-step metaethnographic approach described by Noblit and Hare, which involves cross-interpretation between studies while preserving the context of the primary data. RESULTS: Of 1805 articles identified, 37 were reviewed in detail and 10 were included, using a total of 275 GPs in 7 different countries. Four areas of difficulty specific to the management of multimorbidity emerged from these papers: disorganisation and fragmentation of healthcare; the inadequacy of guidelines and evidence-based medicine; challenges in delivering patient-centred care; and barriers to shared decision-making. A 'line of argument' was drawn which described GPs' sense of isolation in decision-making for multimorbid patients. CONCLUSIONS: This systematic review shows that the problem areas for GPs in the management of multimorbidity may be classified into four domains. There will be no 'one size fits all' intervention for multimorbidity but these domains may be useful targets to guide the development of interventions that will assist and improve the provision of care to multimorbid patients

Energy Use in Existing Dwellings: An Ethnographic Study of Domestic Energy Use Patterns in Ireland

Energy efficiency research in dwellings has traditi onally focused on technical matters, implying increased fabric insulation stand ards and using energy efficient appliances reduces energy consumption. However this research has been shown to have limitations in the form of the impact of polic y and new technologies. As a result there is now widespread recognition of the importan ce for researchers to engage a broader approach of non-technical research of energ y use such as occupant behavior. Monitoring of energy use down to a single appliance is now possible and relatively inexpensive. This paper presents the res ults of an ethnographic study, supported by monitoring, of energy use patterns for six dwellings with a diverse occupant demographic in Ireland. The study supporte d by monitoring found that occupant sex, age and behavior predominantly affect ed energy use followed by the presence of technology rather than the building fab ric itself. Energy use in older technically less efficient dwellings with older occ upants was found to be substantially less than that of the younger occupan ts in supposed more energy efficient houses. When given feedback, occupants we re dispassionate when presented information in terms of energy units (kWh ) but absorbed information straightforwardly once the same information was exp ressed in monetary terms. From the research it is clear that technology and m odern living has had a transformational effect on the way we use energy wh ich pose many problems for the future. Ethnographical research is a long establish ed discipline in the field of social science but its importance is just burgeoning in re lation to understand energy use patterns in buildings. Thus, in addition to the res ults the paper presents the lessons learned during the process and proposes a framework for future ethnographical research of energy use in dwellings

GPs’ perspectives on the management of patients with multimorbidity: systematic review and synthesis of qualitative research

Objective To synthesise the existing published literature on the perceptions of general practitioners (GPs) or their equivalent on the clinical management of multimorbidity and determine targets for future research that aims to improve clinical care in multimorbidity. Design Systematic review and metaethnographic synthesis of primary studies that used qualitative methods to explore GPs’ experiences of clinical management of multimorbidity or multiple chronic diseases. Data sources EMBASE, MEDLINE, CINAHL, PsycInfo, Academic Search Complete, SocIndex, Social Science Full Text and digital theses/online libraries (database inception to September 2012) to identify literature using qualitative methods (focus groups or interviews). Review methods The 7-step metaethnographic approach described by Noblit and Hare, which involves cross-interpretation between studies while preserving the context of the primary data. Results Of 1805 articles identified, 37 were reviewed in detail and 10 were included, using a total of 275 GPs in 7 different countries. Four areas of difficulty specific to the management of multimorbidity emerged from these papers: disorganisation and fragmentation of healthcare; the inadequacy of guidelines and evidence-based medicine; challenges in delivering patient-centred care; and barriers to shared decision-making. A ‘line of argument’ was drawn which described GPs’ sense of isolation in decision-making for multimorbid patients. Conclusions This systematic review shows that the problem areas for GPs in the management of multimorbidity may be classified into four domains. There will be no ‘one size fits all’ intervention for multimorbidity but these domains may be useful targets to guide the development of interventions that will assist and improve the provision of care to multimorbid patients

Adapting a Kidney Exchange Algorithm to Align with Human Values

The efficient and fair allocation of limited resources is a classical problem in economics and computer science. In kidney exchanges, a central market maker allocates living kidney donors to patients in need of an organ. Patients and donors in kidney exchanges are prioritized using ad-hoc weights decided on by committee and then fed into an allocation algorithm that determines who gets what--and who does not. In this paper, we provide an end-to-end methodology for estimating weights of individual participant profiles in a kidney exchange. We first elicit from human subjects a list of patient attributes they consider acceptable for the purpose of prioritizing patients (e.g., medical characteristics, lifestyle choices, and so on). Then, we ask subjects comparison queries between patient profiles and estimate weights in a principled way from their responses. We show how to use these weights in kidney exchange market clearing algorithms. We then evaluate the impact of the weights in simulations and find that the precise numerical values of the weights we computed matter little, other than the ordering of profiles that they imply. However, compared to not prioritizing patients at all, there is a significant effect, with certain classes of patients being (de)prioritized based on the human-elicited value judgments