Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI)is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG)are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD)in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI)is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR)hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP)and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen)has not been established. Regenerative medicine approaches (eg, cell, gene therapies)for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative. © 2019 Society for Vascular Surgery and European Society for Vascular Surger

In spagaat tussen Brussel en Den Haag: De Europeanisering van het wetgevingsvak

Contains fulltext : 78400.pdf (publisher's version ) (Open Access)79 p

Mean-variance optimization for life-cycle pension portfolios

In this thesis we discuss a framework for life-cycle construction. For the construction of life-cycles we use mean-variance optimization. Mean-variance optimization is a portfolio selection method used to find a combination of asset classes that has an optimal risk-return trade-off. We choose the replacement ratio, the pension income as fraction of labour income, as the quantity to be optimized. We find that using mean-variance optimization for the construction of deterministic life-cycles yields results that contradict conventional investment wisdom. It is mean-variance optimal to increase risk-taking as time passes, whereas conventional investment wisdom states that risk should decrease as time goes by. We introduce dynamic mean-variance optimization, where the asset allocation can adapt to changing circumstances, as an alternative to deterministic mean-variance optimization. We introduce an algorithm for dynamic mean-variance optimization of the replacement ratio, an extension of the dynamic mean-variance algorithm by Cong and Oosterlee. We show that dynamic mean-variance optimization can be used for life-cycle construction and that dynamic life-cycles outperform deterministic ones.Electrical Engineering, Mathematics and Computer ScienceDelft Institute of Applied Mathematic

Design of a new terminal device combining voluntary opening and voluntary closing

Upper limb amputees, using a body-powered prosthesis, generate energy with their shoulders which leads to opening or closing of the prosthesis. The preference for one of these types, voluntary opening (VO) or voluntary closing (VC), differs for individuals and for task specifics. Research is, therefore, done regarding terminal devices which provide both types. Earlier presented hybrid devices are heavy, do not provide mechanical advantage or present a difficult switching procedure. A novel VO/VC device was presented, with the promising features of easy switching and good mechanical performance. However, in user tests this device did not perform well, mainly because of its finger shape. The goal of this study is to improve the grasping performance of the VO/VC device. Changing fingers did not create a device which could fulfil all the requirements. Instead, another idea was embodied, prototyped and tested. This device is able switch between VO and VC, by the use of two separate pivot points. Switching between the two is done with a bi-stable mechanism, which is activated by the intact hand. Results show that the device can be used in both modes and that users are able to switch with the bi-stable mechanism, but the mechanical properties do not meet the requirements. Additionally, the device performs less than expected on the user test, due to the bad mechanical properties and misalignments in the 3D-printed prototype. The device created is a good proof of principle for using two pivot points to shift between VO and VC. However, the bi-stable mechanism did not function as expected and a lot of friction is present leading to high forces in the cable. It is recommended to change the material, focus on using other springs which allow for larger opening widths and generate less friction and change the switching system to increase usability and safety.Mechanical Engineerin

Robustness and cross-cultural equivalence of the Cultural Intelligence Scale (CQS)

Contains fulltext : 163211pub.pdf (publisher's version ) (Closed access)- PURPOSE - The purpose of this paper is to assess the cross-cultural equivalence of the four-dimensional 20-item Cultural Intelligence Scale (CQS) and the two-dimensional 12-item cultural intelligence (CQ) short scale. Furthermore, the study elaborates on the results by discussing the differences between culturally equivalent and culturally non-equivalent items. - DESIGN/METHODOLOGY/APPROACH - Data gathered from 607 students with a Chinese or Dutch background and mature international experience serve to test the cross-cultural equivalence of the CQS. - FINDINGS - This study addresses the lack of clarity concerning the cross-cultural equivalence of the CQS in the extended domain of empirical research involving CQ. Furthermore, the consequences of the cultural equivalence tests are discussed. - PRACTICAL IMPLICATIONS - Comparing CQ scores across cultures is only meaningful with the use of the adjusted, two-dimensional scale. Practitioners must be aware of the emic-etic character of the measurement instrument they use. - ORIGINALITY/VALUE - This study addresses the lack of clarity concerning the cross-cultural equivalence of the CQS in the extended domain of empirical research involving CQ. Furthermore, the consequences of the cultural equivalence tests are discussed.26 p