586 research outputs found
Participatory Experimentation with Energy Law:Digging in a ‘Regulatory Sandbox’ for Local Energy Initiatives in the Netherlands
To facilitate energy transition, regulators have devised ‘regulatory sandboxes’ to create a participatory experimentation environment for exploring revision of energy law in several countries. These sandboxes allow for a two-way regulatory dialogue between an experimenter and an approachable regulator to innovate regulation and enable new socio-technical arrangements. However, these experiments do not take place in a vacuum but need to be formulated and implemented in a multi-actor, polycentric decision-making system through collaboration with the regulator but also energy sector incumbents, such as the distribution system operator. Therefore, we are exploring new roles and power division changes in the energy sector as a result of such a regulatory sandbox. We researched the Dutch executive order ‘experiments decentralized, sustainable electricity production’ (EDSEP) that invites homeowners’ associations and energy cooperatives to propose projects that are prohibited by extant regulation. Local experimenters can, for instance, organise peer-to-peer supply and determine their own tariffs for energy transport in order to localize, democratize, and decentralize energy provision. Theoretically, we rely on Ostrom’s concept of polycentricity to study the dynamics between actors that are involved in and engaging with the participatory experiments. Empirically, we examine four approved EDSEP experiments through interviews and document analysis. Our conclusions focus on the potential and limitations of bottom-up, participatory innovation in a polycentric system. The most important lessons are that a more holistic approach to experimentation, inter-actor alignment, providing more incentives, and expert and financial support would benefit bottom-up participatory innovation
Computational Static Aeroelasticity Using Nonlinear Structures and Aerodynamics Models
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106442/1/AIAA2013-1862.pd
Detection of the tulip breaking virus (TBV) in tulips using optical sensors
The tulip breaking virus (TBV) causes severe economic losses for countries that export tulips such as the Netherlands. Infected plants have to be removed from the field as soon as possible. There is an urgent need for a rapid and objective method of screening. In this study, four proximal optical sensing techniques for the detection of TBV in tulip plants were evaluated and compared with a visual assessment by crop experts as well as with an ELISA (enzyme immunoassay) analysis of the same plants. The optical sensor techniques used were an RGB color camera, a spectrophotometer measuring from 350 to 2500 nm, a spectral imaging camera covering a spectral range from 400 to 900 nm and a chlorophyll fluorescence imaging system that measures the photosynthetic activity. Linear discriminant classification was used to compare the results of these optical techniques and the visual assessment with the ELISA score. The spectral imaging system was the best optical technique and its error was only slightly larger than the visual assessment error. The experimental results appear to be promising, and they have led to further research to develop an autonomous robot for the detection and removal of diseased tulip plants in the open field. The application of this robot system will reduce the amount of insecticides and the considerable pressure on labor for selecting diseased plants by the crop expert. © 2010 The Author(s
Cost-effectiveness of hip protectors in frail institutionalized elderly
A randomized controlled trial was performed to examine the cost-effectiveness of external hip protectors in the prevention of hip fractures. Since the hip protectors were not effective in preventing hip fractures in our study, the main objective became to examine whether the use of hip protectors results in lower average costs per participant in the hip protector group as compared with the control group. In addition, the average costs of a hip fracture and subsequent rehabilitation in frail, institutionalized elderly were calculated. Residents from apartment houses for the elderly, homes for the elderly and nursing homes with a high risk for hip fractures were randomized to the hip protector group (n = 276) or control group (n = 285). Costs were calculated for the hip fracture and subsequent rehabilitation until 1 year after the fracture. Six months after each hip fracture, a nurse was interviewed and after 12 months, a questionnaire was sent to the general practitioner or nursing home physician to determine the utilization of health care resources. Differences in costs between the groups were analyzed using non-parametric bootstrapping. Eighteen hip fractures occurred in the intervention group and 20 hip fractures (in 19 persons) in the control group (log rank P-value = 0.86). The average costs per participant, including the costs of the intervention, were €913 in the intervention group and 502 in the control group (cost difference of €-411; 95% confidence interval: -723; 57). The average costs of a hip fracture and subsequent rehabilitation were €8100 (95% CI: 6716-10,010). The use of hip protectors was not associated with lower costs. In addition, the average costs of a hip fracture and subsequent rehabilitation in the first year after the fracture were estimated at €8100 in institutionalized elderly. © International Osteoporosis Foundation and National Osteoporosis Foundation 2004
Clinical osteoarthritis of the hip and knee and fall risk: The role of low physical functioning and pain medication
Objective: Several studies have found an increased fall risk in persons with osteoarthritis (OA). However, most
prospective studies did not use a clinical definition of OA. In addition, it is not clear which factors explain this
risk. Our objectives were: (1) to confirm the prospective association between clinical OA of the hip and knee
and falls; (2) to examine the modifying effect of sex; and (3) to examine whether low physical performance,
low physical activity and use of pain medication are mediating these relationships.
Methods: Baseline and 1-year follow-up data from the European Project on OSteoArthritis (EPOSA) were used
involving pre-harmonized data from five European population-based cohort studies (ages 65 85, n = 2535).
Clinical OA was defined according to American College of Rheumatology (ACR) criteria. Falls were assessed
using self-report.
Results: Over the follow-up period, 27.7% of the participants fell once or more (defined as faller), and 9.8% fell
twice or more (recurrent faller). After adjustment for confounding, clinical knee OA was associated with the
risk of becoming a recurrent faller (relative risk=1.55; 95% confidence interval: 1.10 2.18), but not with the
risk of becoming a faller. No associations between clinical hip OA and (recurrent) falls were observed after
adjustment for confounding. Use of opioids and analgesics mediated the associations between clinical OA
and (recurrent) falls, while physical performance and physical activity did not.
Conclusion: Individuals with clinical knee OA were at increased risk for recurrent falls. This relationship was
mediated by pain medication, particularly opioids. The fall risk needs to be considered when discussing the risk benefit ratio of prescribing these medicationsSources of support: The Longitudinal Aging Study Amsterdam (LASA) is financially supported by the Dutch Ministry of Health, Welfare and Sports (grant no 311669, grant recipient
D.J.H. Deeg). The Pe~nagrande study was partially supported by the National Fund for Health Research (Fondo de Investigaciones en Salud) of Spain (grant no FIS PI 05/1898; FIS
RETICEF RD06/0013/1013 and FIS PS09/02143, grant recipients A. Otero, M.V. Castell). The Hertfordshire Cohort Study is supported by the Medical Research Council of Great Britain,
Versus Arthritis, the British Heart Foundation and the International Osteoporosis Foundation (grant no MRC_MC_UP_A620_1014, grant recipients C. Cooper, E. Dennison). The Italian
cohort was supported by the National Research Council of Italy (CNR), Research Project “Aging: molecular and technological innovations for improving the health of the elderly population"
(Prot. MIUR 2867, grant recipient: S. Maggi). The Swedish Twin Registry is managed by Karolinska Institutet and receives funding through the Swedish Research Council
(grant no 2017-00641, grant recipient Karolinska Institutet
Vitamin D Status and Depressive Symptoms in Older Adults:A Role for Physical Functioning?
Objectives: Depressive symptoms and low vitamin D status are common in older persons and may be associated, but findings are inconsistent. This study investigated whether 25-hydroxyvitamin D (25(OH)D) concentrations are associated with depressive symptoms in older adults, both cross-sectionally and longitudinally. We also examined whether physical functioning could explain this relationship, to gain a better understanding of the underlying mechanisms. Methods: Data from two independent prospective cohorts of the Longitudinal Aging Study Amsterdam were used: an older cohort (≥65 years, n = 1282, assessed from 1995–2002) and a younger-old cohort (55–65 years, n = 737, assessed from 2002–2009). Measurements: Depressive symptoms were measured at baseline and after 3 and 6 years with the Center of Epidemiological Studies Depression Scale. Cross-sectional and longitudinal linear regression techniques were used to examine the relationship between 25(OH)D and depressive symptoms. The mediating role of physical functioning was examined in the longitudinal models. Results: Cross-sectionally, associations were not significant after adjustment for confounders. Longitudinally, women in the older cohort with baseline 25(OH)D concentrations up to 75 nmol/L experienced 175 to 24% more depressive symptoms in the following 6 years, compared with women with 25(OH)D concentrations >75 nmol/L. Reduced physical performance partially mediated this relationship. In men and in the younger-old cohort, no significant associations were observed. Conclusions: Older women showed an inverse relationship between 25(OH)D and depressive symptoms over time, which may partially be explained by declining physical functioning. Replication of these findings by future studies is needed
Universal screening or a universal risk assessment combined with risk-based screening for multidrug-resistant microorganisms upon admission:Comparing strategies
OBJECTIVE: Timely identification of patients who carry multidrug-resistant microorganisms (MDRO) is needed to prevent nosocomial spread to other patients and to the hospital environment. We aimed to compare the yield of a universal screening strategy upon admission to the currently installed universal risk assessment combined with risk-based screening upon admission. METHODS: This observational study was conducted within a prospective cohort study. From January 1, 2018, until September 1, 2019, patients admitted to our hospital were asked to participate. Nasal and perianal samples were taken upon admission and checked for the presence of MDRO. The results of the universal risk assessment and risk-based screening were collected retrospectively from electronic health records. RESULTS: In total, 1017 patients with 1069 separate hospital admissions participated in the study. Universal screening identified 38 (3.6%) unknown MDRO carriers upon admission (37 individual patients), all carrying extended-spectrum beta-lactamase-producing Enterobacterales. For 946 of 1069 (88.5%) patients, both the universal risk assessment and universal screening were performed. For 19 (2.0%) admissions, ≥1 risk factor was identified. The universal risk assessment identified one (0.1%) unknown carrier, compared to 37 out of 946 carriers for the universal screening (P<0.001). Of the 37 carriers identified through the universal screening, 35 (94.6%) reported no risk factors. CONCLUSIONS: Our results show that in our low endemic setting, a universal screening strategy identified significantly more MDRO carriers than the currently implemented universal risk-assessment. When implementing a universal risk-assessment, risk factors should be carefully selected to be able to identify ESBL-E carriers. While the universal screening identified more MDRO carriers, further research is needed to determine the cost-effectiveness of this strategy.</p
The role of plasma concentrations and drug characteristics of beta-blockers in fall risk of older persons
Beta-blocker usage is inconsistently associated with increased fall risk in the literature. However, due to age-related changes and interindividual heterogeneity in pharmacokinetics and dynamics, it is difficult to predict which older adults are more at risk for falls. Therefore, we wanted to explore whether elevated plasma concentrations of selective and nonselective beta-blockers are associated with an increased risk of falls in older beta-blocker users. To answer our research question, we analyzed samples of selective (metoprolol, n = 316) and nonselective beta-blockers (sotalol, timolol, propranolol, and carvedilol, n = 179) users from the B-PROOF cohort. The associations between the beta-blocker concentration and time to first fall were assessed using Cox proportional hazard models. Change of concentration over time in relation to fall risk was assessed with logistic regression models. Models were adjusted for potential confounders. Our results showed that above the median concentration of metoprolol was associated with an increased fall risk (HR 1.55 [1.11–2.16], p =.01). No association was found for nonselective beta-blocker concentrations. Also, changes in concentration over time were not associated with increased fall risk. To conclude, metoprolol plasma concentrations were associated with an increased risk of falls in metoprolol users while no associations were found for nonselective beta-blockers users. This might be caused by a decreased β1-selectivity in high plasma concentrations. In the future, beta-blocker concentrations could potentially help clinicians estimate fall risk in older beta-blockers users and personalize treatment.</p
Dynamics of Staphylococcus aureus in patients and the hospital environment in a tertiary care hospital in the Netherlands
Background: The dynamics of Staphylococcus aureus in patients and the hospital environment are relatively unknown. We studied these dynamics in a tertiary care hospital in the Netherlands. Methods: Nasal samples were taken from adult patients at admission and discharge. Isolates cultured from clinical samples taken before and during hospitalization from these patients were included. Environmental samples of patient rooms were taken over a three-year period. Finally, isolates from clinical samples from patients with an epidemiological link to S. aureus positive rooms were included. Staphylococcal protein A (spa) typing was performed. Results: Nasal samples were taken from 673 patients. One hundred eighteen (17.5%) were positive at admission and discharge, 15 (2.2%) patients acquired S. aureus during hospitalization. Nineteen patients had a positive clinical sample during hospitalization, 15.9% of the S. aureus were considered as from an exogenous source. One hundred and forty (2.8%) environmental samples were S. aureus positive. No persistent contamination of surfaces was observed. Isolates were highly diverse: spa typing was performed for 893 isolates, identifying 278 different spa types, 161 of these spa types were observed only once. Conclusion: Limited transmission could be identified between patients and the hospital environment, and from patient-to-patient. Exogenous acquisition was assumed to occur in 15% of clinical samples. Environmental contamination was infrequent, temporarily, and coincided with the strain from the patient admitted to the room at that time. MRSA was rare and not found in the environment.</p
Development of a clinical prediction model for the onset of functional decline in people aged 65-75 years: Pooled analysis of four European cohort studies
Background: Identifying those people at increased risk of early functional decline in activities of daily living (ADL) is essential for initiating preventive interventions. The aim of this study is to develop and validate a clinical prediction model for onset of functional decline in ADL in three years of follow-up in older people of 65-75 years old. Methods: Four population-based cohort studies were pooled for the analysis: ActiFE-ULM (Germany), ELSA (United Kingdom), InCHIANTI (Italy), LASA (Netherlands). Included participants were 65-75 years old at baseline and reported no limitations in functional ability in ADL at baseline. Functional decline was assessed with two items on basic ADL and three items on instrumental ADL. Participants who reported at least some limitations at three-year follow-up on any of the five items were classified as experiencing functional decline. Multiple logistic regression analysis was used to develop a prediction model, with subsequent bootstrapping for optimism-correction. We applied internal-external cross-validation by alternating the data from the four cohort studies to assess the discrimination and calibration across the cohorts. Results: Two thousand five hundred sixty community-dwelling people were included in the analyses (mean age 69.7 ± 3.0 years old, 47.4% female) of whom 572 (22.3%) reported functional decline at three-year follow-up. The final prediction model included 10 out of 22 predictors: age, handgrip strength, gait speed, five-repeated chair stands time (non-linear association), body mass index, cardiovascular disease, diabetes, chronic obstructive pulmonary disease, arthritis, and depressive symptoms. The optimism-corrected model showed good discrimination with a C statistic of 0.72. The calibration intercept was 0.06 and the calibration slope was 1.05. Internal-external cross-validation showed consistent performance of the model across the four cohorts. Conclusions: Based on pooled cohort data analyses we were able to show that the onset of functional decline in ADL in three years in older people aged 65-75 years can be predicted by specific physical performance measures, age, body mass index, presence of depressive symptoms, and chronic conditions. The prediction model showed good discrimination and calibration, which remained stable across the four cohorts, supporting external validity of our findings
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