121 research outputs found

    A Primer on Cognitive Errors Illustrated Through the Lens of a Neurosurgical Practice

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    Problem Statement: Diagnostic error is often attributed to cognitive errors, including biased thinking patterns, rather than knowledge or data limitations, and education on cognitive bias deserves review in all spheres of practice. Background: The cognitive biases of practitioners create an inherent fallibility in recognizing and treating medical conditions. Awareness of cognitive errors is valuable for mitigating risk of diagnostic error. The impact of cognitive error is substantial in the management of neurosurgically relevant disease. Remarkably broad differential diagnoses often accompany neurologic symptoms. Both focal and non-focal symptoms lend themselves to diagnostic inertia that contributes to errors. Further, initial diagnostic direction can be inaccurate in the involved biological system, anatomic localization, and the pathologic process; thus delaying diagnosis and potentially courting severe consequences. The authors present neurosurgical cases to illustrate the major types of unconscious cognitive errors in medicine using clinically relevant vignettes. Strategies to mitigate cognitive error are also reviewed. Application/Recommendations: Awareness of the types of cognitive errors and de-biasing strategies are valuable to avoid faulty estimation of disease likelihood, avoid overlooking all relevant possibilities, and mitigate error in critical thinking. Recognition that all clinicians are vulnerable to cognitive error exposes the importance of strategies to reduce biases. Efforts to reduce error in medicine can be approached strategically by working to reduce bias and increase discipline in clinical reasoning

    Objeções materialistas contra o dualismo cartesiano

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    I discuss five basic objections materialists often raise to Cartesian Mind-Body Dualism: (1). It is not empirically testable or confirmable; (2). It is in principle testable and confirmable, but unconfirmed; (3). It is testable and confirmable, but has been shown false; (4). It is unnecessary to explain anything; and (5). It cannot serve to explain anything. I will show how unsatisfactory all these objections are. If I am right in what I argue the reductionist posture of contemporary materialism against the existence of Cartesian Immaterial Substances as causal agents in explaining human behavior, is demonstrably more dogma than anything else. Moreover, the promise of reductive materialism to explain human personality, consciousness, and behavior is unlikely ever to be fulfilled.Discutiremos cinco objeções básicas que os materialistas geralmente levantam contra o dualismo mente-corpo cartesiano: (1) Ele não é empiricamente testável ou confirmável; (2) É em princípio testável e confirmável, mas não confirmado; (3) É testável e confirmável, mas foi provado falso; (4) É desnecessário para explicar qualquer coisa; e (5) Não pode servir para explicar coisa alguma. Mostraremos como todas essas objeções são insatisfatórias. Se eu estiver certo em minha argumentação, a postura reducionista do materialismo contemporâneo contra a existência de substâncias cartesianas imateriais como agentes causais para a explicação do comportamento humano é demonstravelmente um dogma mais do que qualquer outra coisa. Ademais, a promessa do materialismo reducionista de explicar a personalidade humana, a consciência e o comportamento tampouco pode ser jamais realizada

    Lead time considerations for the multi-level capacitated lot-sizing problem

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    The classical multi-level capacitated lot-sizing problem is often not suitable to correctly capture resource requirements and precedence relations. We tackle this issue by explicitly modeling these two aspects. Two models are presented; one considering batch production and the other one allowing lot-streaming. Comparisons with traditional models demonstrate the capability of the new approach to deliver more realistic and practically feasible results.Large-scale cases are solved by Benders, which has been enhanced in several novel ways

    Hybrid simulation-optimization methods: A taxonomy and discussion

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    The possibilities of combining simulation and optimization are vast and the appropriate design highly depends on the problem characteristics. Therefore, it is very important to have a good overview of the different approaches. The taxonomies and classifications proposed in the literature do not cover the complete range of methods and overlook some important criteria. We provide a taxonomy that aims at giving an overview of the full spectrum of current simulation-optimization approaches. Our study may guide researchers who want to use one of the existing methods, give insights into the cross-fertilization of the ideas applied in those methods and create a standard for a better communication in the scientific community. Future reviews can use the taxonomy here described to classify both general approaches and methods for specific application fields.The possibilities of combining simulation and optimization are vast and the appropriate design highly depends on the problem characteristics. Therefore, it is very important to have a good overview of the different approaches. The taxonomies and classifications proposed in the literature do not cover the complete range of methods and overlook some important criteria. We provide a taxonomy that aims at giving an overview of the full spectrum of current simulation-optimization approaches. Our study may guide researchers who want to use one of the existing methods, give insights into the cross-fertilization of the ideas applied in those methods and create a standard for a better communication in the scientific community. Future reviews can use the taxonomy here described to classify both general approaches and methods for specific application fields. (C) 2014 Elsevier B.V. All rights reserved

    Using a central Vehicle Holding Compound (VHC) in an open pipeline automotive order fulfilment system: a simulation study

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    Satisfying requests for specific vehicle variants in a timely manner may increase profit margins for the automotive producer and automotive dealers and may reduce the need to incentivise customers financially to make a purchase. Open pipeline order fulfilment systems have emerged in the automotive sector to allow dealers to fulfil a customer in a number of ways. Not only can a dealer search its own stock for a suitable match to a customer’s requested vehicle specification, the dealer can also search for a suitable vehicle in the planning, assembly or distribution pipeline. If a suitable match cannot be found, the dealer can submit a specific Build-to-Order request to the producer. This study examines the impact of adding a central vehicle holding compound (VHC) in such a system. Any dealer can search for a suitable vehicle match in the VHC. A simulation study of a real automotive fulfilment system is conducted to examine the effects on order fulfilment performance of establishing a VHC in a specific market. The simulation model incorporates important features that affect the management and control of the fulfilment system. The study shows that establishing a VHC in an open pipeline system has a significant effect on the level of use of each fulfilment mechanism and on fulfilment performance. A VHC results in significant reductions in lead time but can increase the total stock level in the system if the VHC operating conditions are not determined carefully. The insights and implications of the findings are discussed in detail. They are valuable in providing a base line to consider investment in a VHC and to decide the most appropriate operating policies

    Expression patterns of protein C inhibitor in mouse development

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    Proteolysis of extracellular matrix is an important requirement for embryonic development and is instrumental in processes such as morphogenesis, angiogenesis, and cell migration. Efficient remodeling requires controlled spatio-temporal expression of both the proteases and their inhibitors. Protein C inhibitor (PCI) effectively blocks a range of serine proteases, and recently has been suggested to play a role in cell differentiation and angiogenesis. In this study, we mapped the expression pattern of PCI throughout mouse development using in situ hybridization and immunohistochemistry. We detected a wide-spread, yet distinct expression pattern with prominent PCI levels in skin including vibrissae, and in fore- and hindgut. Further sites of PCI expression were choroid plexus of brain ventricles, heart, skeletal muscles, urogenital tract, and cartilages. A strong and stage-dependent PCI expression was observed in the developing lung. In the pseudoglandular stage, PCI expression was present in distal branching tubules whereas proximal tubules did not express PCI. Later in development, in the saccular stage, PCI expression was restricted to distal bronchioli whereas sacculi did not express PCI. PCI expression declined in postnatal stages and was not detected in adult lungs. In general, embryonic PCI expression indicates multifunctional roles of PCI during mouse development. The expression pattern of PCI during lung development suggests its possible involvement in lung morphogenesis and angiogenesis
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