| 1. |
- McNabb, B, et al.
(författare)
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Using surface velocities to infer ice thickness and bed topography : A case study a Columbia Glacier, Alaska, USA
- 2012
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Ingår i: Journal of Glaciology. - 0022-1430 .- 1727-5652. ; 58:212, s. 1151-1164
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Tidskriftsartikel (refereegranskat)abstract
- Information about glacier volume and ice thickness distribution is essential for manyglaciological applications, but direct measurements of ice thickness can be diffcult and costly. Wepresent a new method that calculates ice thickness via an estimate of ice fux. We solve the familiarcontinuity equation between adjacent fowlines, which decreases the computational time requiredcompared to a solution on the whole grid. We test the method on Columbia Glacier, a large tidewaterglacier in Alaska, USA, and compare calculated and measured ice thicknesses, with favorable results.This shows the potential of this method for estimating ice thickness distribution of glaciers for whichonly surface data are available. We fnd that both the mean thickness and volume of Columbia Glacierwere approximately halved over the period 1957–2007, from 281m to 143m, and from 294km3to134km3, respectively. Using bedrock slope and considering how waves of thickness change propagatethrough the glacier, we conduct a brief analysis of the instability of Columbia Glacier, which leads usto conclude that the rapid portion of the retreat may be nearing an end.
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| 2. |
- Yang, M. M., et al.
(författare)
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Stroke in patients with heart failure and reduced or preserved ejection fraction
- 2023
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Ingår i: European Heart Journal. - 0195-668X. ; 44:31, s. 2998-3013
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Tidskriftsartikel (refereegranskat)abstract
- Aims Stroke is an important problem in patients with heart failure (HF), but the intersection between the two conditions is poorly studied across the range of ejection fraction. The prevalence of history of stroke and related outcomes were investigated in patients with HF. Methods and results Individual patient meta-analysis of seven clinical trials enrolling patients with HF with reduced (HFrEF) and preserved ejection fraction (HFpEF). Of the 20 159 patients with HFrEF, 1683 (8.3%) had a history of stroke, and of the 13 252 patients with HFpEF, 1287 (9.7%) had a history of stroke. Regardless of ejection fraction, patients with a history of stroke had more vascular comorbidity and worse HF. Among those with HFrEF, the incidence of the composite of cardiovascular death, HF hospitalization, stroke, or myocardial infarction was 18.23 (16.81-19.77) per 100 person-years in those with prior stroke vs. 13.12 (12.77-13.48) in those without [hazard ratio 1.37 (1.26-1.49), P < 0.001]. The corresponding rates in patients with HFpEF were 14.16 (12.96-15.48) and 9.37 (9.06-9.70) [hazard ratio 1.49 (1.36-1.64), P < 0.001]. Each component of the composite was more frequent in patients with stroke history, and the risk of future stroke was doubled in patients with prior stroke. Among patients with prior stroke, 30% with concomitant atrial fibrillation were not anticoagulated, and 29% with arterial disease were not taking statins; 17% with HFrEF and 38% with HFpEF had uncontrolled systolic blood pressure (& GE;140 mmHg). Conclusion Heart failure patients with a history of stroke are at high risk of subsequent cardiovascular events, and targeting underutilization of guideline-recommended treatments might be a way to improve outcomes in this high-risk population.
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