1,644 research outputs found
The sour and sweet grapes of an institutional transition: Impacts of institutional transition on public policy design in water management sector in the Netherlands
The last decade a general shift has been realized in the water management sector in the Netherlands. The shift from a top-down (cooperative monopoloid) to a bottom-up institutional setting (cooperative multi-centric) was accompanied by various effects on the societal context. The benefits of the institutional shift do not only involve the most important actors (e.g. the Ministry of Transport and Water Management, the Municipalities) but also allows them to achieve their goals. The disadvantages of the institutional shift concern the long duration of the policy design process since issues and perceptions are steered in multiple phases and negotiated at all levels of institutional structuration. These undesirable effects can be considered as the impacts of the institutional transitions and can be alleviated by a more thorough design of the policy design process along the administrative layers as well as by the sustaining of openness and diversity of actors in the policy design process. The fruitful cooperative climate between the involved administrative bodies of water management sectors need to be conserved for forthcoming water policy challenges
A biomechanical model of anther opening reveals the roles of dehydration and secondary thickening
Understanding the processes that underlie pollen release is a prime target for controlling fertility to enable selective breeding and the efficient production of hybrid crops. Pollen release requires anther opening, which involves changes in the biomechanical properties of the anther wall. In this research, we develop and use a mathematical model to understand how these biomechanical processes lead to anther opening
CONVINCE in the context of existing evidence on haemodiafiltration
Haemodiafiltration (HDF) provides a greater removal of larger solutes and protein-bound compounds than conventional high-flux haemodialysis (HD). There are indications that the patients receiving the highest convection volumes of HDF result in improved survival compared with HD. However, the comparative efficacy of HDF versus HD remains unproven. Here we provide a comparative account of the methodology and aims of âthe comparison of high-dose HDF with high-flux HDâ (CONVINCE) study in the context of the totality of evidence and how this study will contribute to reaching a higher level of certainty regarding the comparative efficacy of HDF versus HD in people with end-stage kidney disease
Long-term health benefits and costs of measurement of carotid intima-media thickness in prevention of coronary heart disease
OBJECTIVE: Recently, it was demonstrated that information on carotid intima-media thickness (CIMT) and plaque may improve coronary heart disease (CHD) risk prediction through reclassification of some individuals to the correct risk category using the Framingham risk score. Our objective was to assess the currently unknown cost-effectiveness of CIMT measurements in primary prevention. METHODS: A hypothetical cohort of men and women aged 50-59 years and at intermediate or high CHD risk based on data from the Atherosclerosis Risk in Communities Study was simulated using a Markov model. Myocardial infarction (MI) events were used as a proxy for CHD. The effectiveness of pharmaceutical treatment was varied in the analysis. Sensitivity analysis was performed to obtain robust results. RESULTS: CIMT-based reclassification induced a 1% lower absolute risk of MI and 0.01-0.02 increase in quality-adjusted life years (QALYs) for men, and a 1-3% lower risk, and 0.03-0.05 increase in QALYs for women, over a period of 20-30 years. Corresponding costs were an additional 200-300 per woman. Over a 10-year period CIMT measurements were cost-effective with a probability of 66% (men), and 94% (women). Over a 30-year period, CIMT measurements had acceptable cost-effectiveness for men and women. CONCLUSION: Performing CIMT measurements in asymptomatic men and women aged 50-59 years results in additional, but small, health benefits. It takes time for these health benefits to outweigh the initial CIMT measurement costs. Our results support CIMT measurements for cardiovascular risk stratification, in particular for women, when focusing on long-term health
Addressing persistent evidence gaps in cardiovascular sex differences research â the potential of clinical care data
Women have historically been underrepresented in cardiovascular clinical trials, resulting in a lack of sex-specific data. This is especially problematic in two situations, namely those where diseases manifest differently in women and men and those where biological differences between the sexes might affect the efficacy and/or safety of medication. There is therefore a pressing need for datasets with proper representation of women to address questions related to these situations. Clinical care data could fit this bill nicely because of their unique broad scope across both patient groups and clinical measures. This perspective piece presents the potential of clinical care data in sex differences research and discusses current challenges clinical care data-based research faces. It also suggests strategies to reduce the effect of these limitations, and explores whether clinical care data alone will be sufficient to close evidence gaps or whether a more comprehensive approach is needed
Convenience and satisfaction in direct oral anticoagulant-treated patients with atrial fibrillation
Abstract Background Direct oral anticoagulants (DOACs) are the preferred anticoagulants for thromboprophylaxis in atrial fibrillation. We aimed to identify determinants of quality of life related to DOAC treatment to optimize DOAC treatment convenience and satisfaction. Methods We conducted a crossâsectional study in DOAC users. DOAC treatmentârelated convenience and satisfaction were measured by Perception of Anticoagulant Treatment Questionnaire. Higher scores are more favorable (range, 0â100). Patientâreported outcome measures and drugâ and organizationârelated factors were collected. Multiple regression analyses were used to evaluate the association between these factors (ie, exposure variables) and DOAC treatmentârelated convenience and treatment satisfaction (ie, outcome variables). Results Of 1598 patients invited, 1035 responded, and 962 were included. The median convenience score was 98.1 (94.2â100.0), mean satisfaction score 66.5± 14.9. Twentyâfour percent felt not well informed at the start of DOAC; 6.9% did not know who to turn to with questions. Multiple regression analyses showed that lacking sense of security, the predefined composite of receiving insufficient information at start of DOAC and/or not knowing who to turn to with questions was associated with lower convenience (regression coefficient, â1.29; 95% confidence interval [CI], â2.16 to â0.41). Bleeding, gastrointestinal complaints, and lower medication adherence were also associated with lower convenience. Missing sense of security (regression coefficient â6.59; 95% CI, â8.94 to â4.24) and bleeding without consultation were associated with lower treatment satisfaction. Conclusions Accessible interventions to improve DOAC care could be providing more instruction at treatment initiation and ensuring that patients know who to contact in case of problems
Evaluating a cardiovascular disease risk management care continuum within a learning healthcare system: a prospective cohort study
Background: Many patients now present with multimorbidity and chronicity of disease. This means that multidisciplinary management in a care continuum, integrating primary care and hospital care services, is needed to ensure high quality care. Aim: To evaluate cardiovascular risk management (CVRM) via linkage of health data sources, as an example of a multidisciplinary continuum within a learning healthcare system (LHS). Design & setting: In this prospective cohort study, data were linked from the Utrecht Cardiovascular Cohort (UCC) to the Julius General Practitioners' Network (JGPN) database. UCC offers structured CVRM at referral to the University Medical Centre (UMC) Utrecht. JGPN consists of electronic health record (EHR) data from referring GPs. Method: The cardiovascular risk factors were extracted for each patient 13 months before referral (JGPN), at UCC inclusion, and during 12 months follow-up (JGPN). The following areas were assessed: registration of risk factors; detection of risk factor(s) requiring treatment at UCC; communication of risk factors and actionable suggestions from the specialist to the GP; and change of management during follow-up. Results: In 52% of patients, >1 risk factors were registered (that is, extractable from structured fields within routine care health records) before UCC. In 12%â72% of patients, risk factor(s) existed that required (change or start of) treatment at UCC inclusion. Specialist communication included the complete risk profile in 67% of letters, but lacked actionable suggestions in 86%. In 29% of patients, at least one risk factor was registered after UCC. Change in management in GP records was seen in 21%-58% of them. Conclusion: Evaluation of a multidisciplinary LHS is possible via linkage of health data sources. Efforts have to be made to improve registration in primary care, as well as communication on findings and actionable suggestions for follow-up to bridge the gap in the CVRM continuum
Reaction pathways and textural aspects of the replacement of anhydrite by calcite at 25 °C
The replacement of sulfate minerals by calcium carbonate polymorphs (carbonation) has important implications in various geological processes occurring in Earth surface environments. In this paper we report the results of an experimental study of the interaction between anhydrite (100), (010), and (001) surfaces and NaâCOâ aqueous solutions under ambient conditions. Carbonation progress was monitored by glancing incidence X-ray diffraction (GIXRD) and scanning electron microscopy (SEM). We show that the reaction progresses through the dissolution of anhydrite and the simultaneous growth of calcite. The growth of calcite occurs oriented on the three anhydrite cleavage surfaces and its formation is accompanied by minor vaterite. The progress of the carbonation always occurs from the outer-ward to the inner-ward surfaces and its rate depends on the anhydrite surface considered, with the (001) surface being much more reactive than the (010) and (100) surfaces. The thickness of the formed carbonate layer grows linearly with time. The original external shape of the anhydrite crystals and their surface details (e.g., cleavage steps) are preserved during the carbonation reaction. Textural characteristics of the transformed regions, such as the gradation in the size of calcite crystals, from ~2 ÎŒm in the outer region to ~17 ÎŒm at the calcite-anhydrite interface, the local preservation of calcite crystalographic orientation with respect to anhydrite and the distribution of the microporosity mainly within the carbonate layer without development of any significant gap at the calcite-anhydrite interface. Finally, we compare these results on anhydrite carbonation with those on gypsum carbonation and can explain the differences on the basis of four parameters: (1) the molar volume change involved in the replacement process in each case, (2) the lack/existence of epitactic growth between parent and product phases, (3) the kinetics of dissolution of the different surfaces, and (4) the chemical composition (amount of structural water) of the parent phases
Analyse a posteriori d'une démarche d'observatoire dans un contexte conflictuel : cas de l'irrigation en Charente
La situation de l'irrigation en Poitou-Charentes est emblĂ©matique des tensions entre le monde agricole et la sociĂ©tĂ©. Pour dĂ©passer ces conflits, un observatoire alliant systĂšme d'information et action collective a Ă©tĂ© mis en place en Charente Ă l'initiative d'un collectif regroupant responsables politiques, chercheurs et conseillers agricoles. Cet article a pour objectif de restituer l'analyse des diffĂ©rentes perspectives et attentes des acteurs ayant participĂ© Ă l'Ă©laboration de l'observatoire. L'analyse proposĂ©e s'appuie sur une enquĂȘte rĂ©alisĂ©e en 2006 auprĂšs des acteurs concernĂ©s. Il en ressort un cadre que nous proposons d'utiliser lors de la conception d'observatoires afin d'expliciter la diversitĂ© des attentes des parties prenantes et de faciliter l'Ă©laboration d'un accord prĂ©alable Ă leur mise en Âœuvre. / Irrigation in Poitou-Charentes exemplifies the tensions that exist between agriculture and other societal sectors. To overcome these conflicts, a Community Information System (CIS) for the purpose of both data management and community development has been set up in Charente by a group of policymakers, researchers and agricultural advisers. This paper describes our analysis of the differences among participants in the development of this CIS in terms of their points of view and expectations. Drawing on an analysis of a set of interviews conducted with these stakeholders in 2006, we propose a framework for use during the initial design phase of a CIS to make stakeholder expectations explicit and to promote a shared understanding prior to setting up a CIS
Ferrihydrite formation : the role of Fe13 Keggin clusters
Ferrihydrite is the most common iron oxyhydroxide found in soil and is a key sequester of contaminants in the environment. Ferrihydrite formation is also a common component of many treatment processes for clean-up of industrial effluents. Here we characterize ferrihydrite formation during the titration of an acidic ferric nitrate solution with NaOH. In-situ SAXS measurements supported by ex situ TEM indicate that initailly Fe13 Keggin clusters (radius ~0.45 nm) form in solution at pH 0.5 - 1.5, and are persistant for at least 18 days. The Fe13 clusters begin to aggregate above ~ pH 1, initially forming highly linear structures. Above pH ~ 2 densification of the aggregates occurs in conjunction with precipiation of low molecular weight Fe(III) speices (e.g. monomers, dimers) to form mass fractal aggregates of ferrihydrite nanoparticles (~ 3 nm) in which the Fe13 Keggin motif is preserved. SAXS analysis indicates the ferrihydrite particles have a core-shell structure consisting of a Keggin center surrounded by a Fe-depleted shell, supporting the surface depleted model of ferrihydrite. Overall, we present the first direct evidence for the role of Fe13 clusters in the pathway of ferrihydrite formation during base hydrolysis, showing clear structural continuity from isolated Fe13 Keggins to the ferrihydrite particle structure. The results have direct relevance to the fundamental understanding of ferrihydrite formation in environmental, engineered and industrial processes
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