110 research outputs found

    Flexible automation and the loss of pooling synergy

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    This paper focuses on the effects of flexible automation on the performance of a job shop. Flexible automated machines may significantly improve the delivery performance and the flow time of jobs. The insertion of a flexible automated system in a job shop, however, also has a counter effect on the manufacturing performance. This is caused by the reduction of pooling synergy due to the dedication implied by flexible automated machines. This paper investigates by means of a simulation study to what extent the loss of pooling synergy will deteriorate job shop performance. Simulation is also used to indicate the level of efficiency of the automated machinery needed to overcome the negative effect of the loss of pooling synergy. The simulation study also highlights the importance of appropriate off-line assignment rules, which assign jobs to either the conventional or automated machines. Major conclusion of this paper is that the ‘pooling loss effect’ should be taken into account in the design and justification of new flexible automated machinery. The design of appropriate offline assignment rules, furthermore, has to be seen as an integral part of investment in new technology.

    Flexible automation and the loss of pooling synergy

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    Flexible automation and the loss of pooling synergy

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    Analysis of the role of General Practice in preventing Avoidable Hospitalisation through a multilevel approach

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    Objective. To examine the relationship between Avoidable Hospitalisation (AH) and the activities of General Practitioners (GPs). The study was carried out in the Lazio Region (Italy) within different organizational models of primary care (PC) delivery. Methods: Secondary data of a set of GP activities delivered to the Lazio population as listed in the Lazio GPs in 2008, were used. For each GP a set of health services delivered to the patients on their practice lists were measured. The relation between the rates of AH, acute and chronic conditions separately, and the rates of such health services were analyzed through the use of a multilevel Poisson regression model, adjusted according to patients’ health status. Results: The study included data from all the active GPs (4,837) in the Lazio Region and their 4,666,037 registered patients. The overall AH rate of the registered patients was 7.7 per 1,000, 2.2 for acute and 5.5 for chronic conditions. The diagnostics prescription by GPs is associated with a 7% (IRR=0.93;95% C.I.:0.89-0.97) reduction of the chronic AH rate. Patients registered at GPs working within a team practice resulted in a hospitalisation rate decrease of 5% (IRR= 0.95; 95% C.I.:0.91-0.99)  for avoidable acute conditions. Conclusion: The study showed that the role of GPs in preventing AH is substantial, particularly when team practice is performed and specifically when additional diagnostics are prescribed. The study is further evidence in favor of the validity of AH as an outcome measure of quality and accessibility of primary care

    Tres nuevas especies de killis (Cyprinodontiformes: Nothobranchiidae) de Guinea Ecuatorial

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    Two new Mesoaphyosemion species and one new species of the ’Aphyosemion’ herzogi group are described from the inland of Equatorial Guinea. The results of mtDNA analyses of most of the known phenotypes of the genus Mesoaphyosemion and the ‘Aphyosemion’ herzogi species group, respectively, are presented. Both new Mesoaphyosemion species have dark blotches on the posterior flanks and resemble M. maculatum from Gabon, yet they are not closely related to that species. Although the two new species occur in very close proximity, DNA results suggest no close relationship. The ‘Aphyosemion’ herzogi species group has a similar distribution as the genus Mesoaphyosemion, but with its northern boundary in southern Cameroon. Based on mtDNA the new ‘Aphyosemion’ from the Mitemele drainage in south west Equatorial Guinea is basal species to the remaining species group. It is distinguished from the two described congeners, ‘A.’ bochtleri and ‘A.’ herzogi by a diagnostic combination of colouration characters. Unpaired fins and flanks have a green background and caudal peduncle is often yellow to golden with dark red irregular dark red bars. The genetic dataindicate that the species group contains several additional, genetically and by colour pattern well separated, potentiallyundescribedspecies. urn:lsid:zoobank.org:pub:2752DAEA-BEFE-4D6D-8D5C-FB3F0D265A4DSe describen para la parte continental de Guinea Ecuatorial dos nuevas especies de Mesoaphyosemion y una nueva especie del grupo de especies â€˜Aphyosemion’ herzogi. También, se presentan los resultados de los análisis de DNAmt de casi todos los fenotipos conocidos del género Mesoaphyosemion y del grupo de especies ‘Aphyosemion’ herzogi. Ambas nuevas especies de Mesoaphyosemion tienen manchas oscuras en los flancos posteriores y se parecen a M. maculatum de Gabón, pero no están estrechamente relacionadas con esa especie. Aunque las dos nuevas especies son próximas, los resultados del ADN sugieren que no existe entre ellas una relación cercana. El grupo de especies ‘Aphyosemion’ herzogi tiene una distribución similar a la de Mesoaphyosemion, pero con su límite norte en el sur de Camerún. Basado en ADNmt, el nuevo ‘Aphyosemion’ de la cuenca del río Mitemele, en el suroeste de la parte continental de Guinea Ecuatorial, es una especie basal al resto de las especies estudiadas. Se distingue de los dos congéneres descritos, ‘A.’ bochtleri y ‘A.’ herzogi por una combinación de caracteres diagnósticos de la coloración. Las aletas impares y los flancostienen un fondo verde y el pedúnculo caudal suele ser de color amarillo a dorado con barras rojo oscuro irregulares. Los datos genéticosindicanque el grupo de especies contiene varias especies más, que están genéticamente y por patrón de coloración bien delimitadas, y que no han sido formalmente descritas

    Entrustable Professional Activities in Residency Programs – planning and scheduling issues

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    [EN] Residency programs allow residents, i.e., graduate physicians, to qualify for being a specialist in one of the medical disciplines. Their educational programme is strongly focusing on competencies and skills, but will incur a major change in the near future in order to introduce Entrustable Professional Activities (EPA’s). EPA’s focus on actual physician tasks and are assessed by supervisors in the clinic. The trust levels indicate whether trainees are ready for the next milestone, such as unsupervised practice, based on assessment of performance of those activities. EPA’s have not only effect on the internships and the assessment process, but also impact the planning and scheduling of the educational programmes, internships, patient care services, and co-operation between regional hospitals. This study examines the effect on the planning and scheduling process and proposes a framework for planning and scheduling in order to facilitate the organization of this type of educational programs. The main improvements have to be found in an improved regional coordination between the hospitals, a more leading role for the educational programme directors, and more intelligent planning and scheduling.Riezebos, J.; Van Der Zee, DJ.; Pruim, J. (2019). Entrustable Professional Activities in Residency Programs – planning and scheduling issues. En HEAD'19. 5th International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 891-899. https://doi.org/10.4995/HEAD19.2019.9274OCS89189

    Cost-effectiveness of Direct Transfer to Angiography Suite of Patients With Suspected Large Vessel Occlusion

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    Cost-effectiveness; Angiography; Large vessel occlusionCost-efectivitat; Angiografia; Oclusió de grans vasosCosto-efectividad; Angiografía; Oclusión de grandes vasosBackground and Objectives Patients with acute ischemic stroke due to large vessel occlusion (LVO) deemed eligible for endovascular thrombectomy (EVT) are transferred from the emergency room to the angiography suite to undergo the procedure. Recently, the strategy of direct transfer of patients with suspected LVO to the angiography suite (DTAS) has been shown to improve functional outcomes. This study aims to evaluate the cost-effectiveness of the DTAS strategy vs initial transfer of patients with suspected LVO (Rapid Arterial Occlusion Evaluation score >4 and NIH Stroke Scale >10) to the emergency room (ITER). Methods A decision-analytic Markov model was developed to estimate the cost-effectiveness of the DTAS strategy vs the ITER strategy from a Dutch health care perspective with a 10-year time horizon. The primary outcome was the incremental cost-effectiveness ratio (ICER) using Dutch thresholds of 59,135(€50,000)and59,135 (€50,000) and 94,616 (€80,000) per quality-adjusted life year (QALY). Uncertainty of input parameters was assessed using 1-way sensitivity analysis, scenario analysis, and probabilistic sensitivity analysis. Results The DTAS strategy yielded 0.65 additional QALYs at an additional 16,089,resultinginanICERof16,089, resulting in an ICER of 24,925/QALY compared with the ITER strategy. The ICER varied from 27,169to27,169 to 38,325/QALY across different scenarios. The probabilistic sensitivity analysis showed that the DTAS strategy had a 91.8% and 97.0% likelihood of being cost-effective at a decision threshold of 59,135/QALYand59,135/QALY and 94,616/QALY, respectively. Discussion The cost-effectiveness of the DTAS strategy over ITER is robust for patients with suspected LVO. Together with recently published clinical results, this means that implementation of the DTAS strategy may be considered to improve the workflow and outcome of EVT.The CONTRAST consortium is supported by Netherlands Cardiovascular Research Initiative, an initiative of the Dutch Heart Foundation (CVON2015-01: CONTRAST) and by the Brain Foundation Netherlands (HA2015.01.06) and powered by Health∼Holland, Top Sector Life Sciences and receives unrestricted funding from Medtronic and Cerenovus. The collaboration project is additionally financed by the Ministry of Economic Affairs by means of the PPP Allowance made available by the Top Sector Life Sciences & Health to stimulate public-private partnerships (LSHM17016). This work was funded in part through unrestricted funding by Stryker, Medtronic and Cerenovus

    Treatment of heart failure in Dutch general practice

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    BACKGROUND: To study the relation between the prescription rates of selected cardiovascular drugs (ACE-inhibitors and Angiotensin receptor blockers, beta-blockers, diuretics, and combinations), sociodemographic factors (age, gender and socioeconomic class) and concomitant diseases (hypertension, coronary heart disease, cerebrovascular accident, heart valve disease, atrial fibrillation, diabetes mellitus and asthma/COPD) among patients with heart failure cared for in general practice. METHODS: Data from the second Dutch National Survey in General Practice, conducted mainly in 2001. In this study the data of 96 practices with a registered patient population of 374.000 were used. Data included diagnosis made during one year by general practitioners, derived from the electronic medical records, prescriptions for medication and sociodemographic characteristics collected via a postal questionnary (response 76%) RESULTS: A diagnosis of HF was found with 2771 patients (7.1 in 1000). Their mean age was 77.7 years, 68% was 75 years or older, 55% of the patients were women. Overall prescription rates for RAAS-I, beta-blockers and diuretics were 50%, 32%, 86%, respectively, whereas a combination of these three drugs was prescribed in 18%. Variations in prescription rates were mainly related to age and concomitant diseases. CONCLUSION: Prescription is not influenced by gender, to a small degree influenced by socioeconomic status and to a large degree by age and concomitant diseases

    Pathway Design for Acute Stroke Care in the Era of Endovascular Thrombectomy:A Critical Overview of Optimization Efforts

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    The efficacy of intravenous thrombolysis and endovascular thrombectomy (EVT) for acute ischemic stroke is highly time dependent. Optimal organization of acute stroke care is therefore important to reduce treatment delays but has become more complex after the introduction of EVT as regular treatment for large vessel occlusions. There is no singular optimal organizational model that can be generalized to different geographic regions worldwide. Current dominant organizational models for EVT include the drip-and-ship- and mothership model. Guidelines recommend routing of suspected patients with stroke to the nearest intravenous thrombolysis capable facility; however, the choice of routing to a certain model should depend on regional stroke service organization and individual patient characteristics. In general, design approaches for organizing stroke care are required, in which 2 key strategies could be considered. The first entails the identification of interventions within existing organizational models for optimizing timely delivery of intravenous thrombolysis and/or EVT. This includes adaptive patient routing toward a comprehensive stroke center, which focuses particularly on prehospital triage tools; bringing intravenous thrombolysis or EVT to the location of the patient; and expediting services and processes along the stroke pathway. The second strategy is to develop analytical or simulation model-based approaches enabling the design and evaluation of organizational models before their implementation. Organizational models for acute stroke care need to take regional and patient characteristics into account and can most efficiently be assessed and optimized through the application of model-based approaches

    Entering new fields of simulation application - challenges faced in simulation modelling of stroke systems

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    Stroke is a major cause of death and long-term disability world-wide. To improve functional outcome treatment with intravenous tissue plasminogen activator (tPA) is the most effective medical treatment for acute brain infarction within 4.5 hours after the onset of stroke symptoms. Unfortunately, tPA remains substantially underutilized. Acute stroke care organization is among the dominant factors determining undertreatment. Recently, simulation has been suggested and successfully implemented as a tool for optimizing stroke care pathway logistics. Starting from a number of pioneering simulation studies challenges in simulation application and simulation methodology are identified. The definition of a domain specific modelling framework for acute stroke care is advocated to master system complexities, facilitate joint team work in solution finding, organize model data collection and make a further entrance to the field
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