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

Global variability in leaf respiration in relation to climate, plant functional types and leaf traits

• Leaf dark respiration (Rdark) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of Rdark and associated leaf traits. • Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwoody plant functional types (PFTs) were represented. Mixed-effects models were used to disentangle sources of variation in Rdark. • Area-based Rdark at the prevailing average daily growth temperature (T) of each site increased only twofold from the Arctic to the tropics, despite a 20°C increase in growing T (8–28°C). By contrast, Rdark at a standard T (25°C, Rdark25) was threefold higher in the Arctic than in the tropics, and twofold higher at arid than at mesic sites. Species and PFTs at cold sites exhibited higher Rdark25 at a given photosynthetic capacity (Vcmax25) or leaf nitrogen concentration ([N]) than species at warmer sites. Rdark25 values at any given Vcmax25 or [N] were higher in herbs than in woody plants. • The results highlight variation in Rdark among species and across global gradients in T and aridity. In addition to their ecological significance, the results provide a framework for improving representation of Rdark in terrestrial biosphere models (TBMs) and associated land-surface components of Earth system models (ESMs)

Cursed Capital: the Economic Impact of the Transatlantic Slave Trade on Walcheren around 1770

The island of Walcheren in the province of Zeeland was the largest Dutch slaving center in the eighteenth century. While the profitability of the slave trade itself was limited, it had important local economic effects. A clue comes from the excellently preserved archive of the largest slave trader: the Middelburgse Commercie Compagnie (MCC). Combining the figures in the MCC archive with some experimental calculations, it is estimated that around 1770 about a tenth of the income earned by inhabitants of Middelburg was connected to the trade in enslaved Africans. For the more specialized and smaller city of Flushing, this figure was likely closer to a third of all income

Cursed Capital: the Economic Impact of the Transatlantic Slave Trade on Walcheren around 1770

The island of Walcheren in the province of Zeeland was the largest Dutch slaving center in the eighteenth century. While the profitability of the slave trade itself was limited, it had important local economic effects. A clue comes from the excellently preserved archive of the largest slave trader: the Middelburgse Commercie Compagnie (MCC). Combining the figures in the MCC archive with some experimental calculations, it is estimated that around 1770 about a tenth of the income earned by inhabitants of Middelburg was connected to the trade in enslaved Africans. For the more specialized and smaller city of Flushing, this figure was likely closer to a third of all income

Cursed Capital: the Economic Impact of the Transatlantic Slave Trade on Walcheren around 1770

The island of Walcheren in the province of Zeeland was the largest Dutch slaving center in the eighteenth century. While the profitability of the slave trade itself was limited, it had important local economic effects. A clue comes from the excellently preserved archive of the largest slave trader: the Middelburgse Commercie Compagnie (MCC). Combining the figures in the MCC archive with some experimental calculations, it is estimated that around 1770 about a tenth of the income earned by inhabitants of Middelburg was connected to the trade in enslaved Africans. For the more specialized and smaller city of Flushing, this figure was likely closer to a third of all income