| 1. |
- Farinotti, Daniel, et al.
(författare)
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How accurate are estimates of glacier ice thickness? Results from ITMIX, the Ice Thickness Models Intercomparison eXperiment
- 2017
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Ingår i: The Cryosphere. - : Copernicus GmbH. - 1994-0416 .- 1994-0424. ; 11, s. 949-970
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of the ice thickness distribution of glaciers and ice caps is an important prerequisite for many glaciological and hydrological investigations. A wealth of approaches has recently been presented for inferring ice thickness from characteristics of the surface. With the Ice Thickness Models Intercomparison eXperiment (ITMIX) we performed the first coordinated assessment quantifying individual model performance. A set of 17 different models showed that individual ice thickness estimates can differ considerably – locally by a spread comparable to the observed thickness. Averaging the results of multiple models, however, significantly improved the results: on average over the 21 considered test cases, comparison against direct ice thickness measurements revealed deviations on the order of 10 ± 24 % of the mean ice thickness (1σ estimate). Models relying on multiple data sets – such as surface ice velocity fields, surface mass balance, or rates of ice thickness change – showed high sensitivity to input data quality. Together with the requirement of being able to handle large regions in an automated fashion, the capacity of better accounting for uncertainties in the input data will be a key for an improved next generation of ice thickness estimation approaches.
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| 2. |
- Cherian, Dennis, 1989-, et al.
(författare)
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Flexible Organic Electronic Ion Pump Fabricated Using Inkjet Printing and Microfabrication for Precision In Vitro Delivery of Bupivacaine
- 2023
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Ingår i: Advanced Healthcare Materials. - : John Wiley and Sons Inc. - 2192-2640 .- 2192-2659. ; 12:24, s. 2300550-
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Tidskriftsartikel (refereegranskat)abstract
- The organic electronic ion pump (OEIP) is an on-demand electrophoretic drug delivery device, that via electronic to ionic signal conversion enables drug delivery without additional pressure or volume changes. The fundamental component of OEIPs is their polyelectrolyte membranes which are shaped into ionic channels that conduct and deliver ionic drugs, with high spatiotemporal resolution. The patterning of these membranes is essential in OEIP devices and is typically achieved using laborious microprocessing techniques. Here, the development of an inkjet printable formulation of polyelectrolyte is reported, based on a custom anionically functionalized hyperbranched polyglycerol (i-AHPG). This polyelectrolyte ink greatly simplifies the fabrication process and is used in the production of free-standing OEIPs on flexible polyimide (PI) substrates. Both i-AHPG and the OEIP devices are characterized, exhibiting favorable iontronic characteristics of charge selectivity and the ability to transport aromatic compounds. Further, the applicability of these technologies is demonstrated by the transport and delivery of the pharmaceutical compound bupivacaine to dorsal root ganglion cells with high spatial precision and effective nerve blocking, highlighting the applicability of these technologies for biomedical scenarios. © 2023 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
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| 3. |
- Farinotti, Daniel, et al.
(författare)
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Results from the Ice Thickness Models Intercomparison eXperiment Phase 2 (ITMIX2)
- 2021
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Ingår i: Frontiers in Earth Science. - : Frontiers Media S.A.. - 2296-6463. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Knowing the ice thickness distribution of a glacier is of fundamental importance for a number of applications, ranging from the planning of glaciological fieldwork to the assessments of future sea-level change. Across spatial scales, however, this knowledge is limited by the paucity and discrete character of available thickness observations. To obtain a spatially coherent distribution of the glacier ice thickness, interpolation or numerical models have to be used. Whilst the first phase of the Ice Thickness Models Intercomparison eXperiment (ITMIX) focused on approaches that estimate such spatial information from characteristics of the glacier surface alone, ITMIX2 sought insights for the capability of the models to extract information from a limited number of thickness observations. The analyses were designed around 23 test cases comprising both real-world and synthetic glaciers, with each test case comprising a set of 16 different experiments mimicking possible scenarios of data availability. A total of 13 models participated in the experiments. The results show that the inter-model variability in the calculated local thickness is high, and that for unmeasured locations, deviations of 16% of the mean glacier thickness are typical (median estimate, three-quarters of the deviations within 37% of the mean glacier thickness). This notwithstanding, limited sets of ice thickness observations are shown to be effective in constraining the mean glacier thickness, demonstrating the value of even partial surveys. Whilst the results are only weakly affected by the spatial distribution of the observations, surveys that preferentially sample the lowest glacier elevations are found to cause a systematic underestimation of the thickness in several models. Conversely, a preferential sampling of the thickest glacier parts proves effective in reducing the deviations. The response to the availability of ice thickness observations is characteristic to each approach and varies across models. On average across models, the deviation between modeled and observed thickness increase by 8.5% of the mean ice thickness every time the distance to the closest observation increases by a factor of 10. No single best model emerges from the analyses, confirming the added value of using model ensembles.
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| 4. |
- Roy, Arghyamalya, 1992-, et al.
(författare)
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Electrophoretic Delivery of Clinically Approved Anesthetic Drug for Chronic Pain Therapy
- 2023
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Ingår i: Advanced Therapeutics. - : John Wiley and Sons Inc. - 2366-3987. ; 6:7
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Tidskriftsartikel (refereegranskat)abstract
- Despite a range of available pain therapies, most patients report so-called “breakthrough pain.” Coupled with global issues like opioid abuse, there is a clear need for advanced therapies and technologies for safe and effective pain management. Here the authors demonstrate a candidate for such an advanced therapy: precise and fluid-flow-free electrophoretic delivery via organic electronic ion pumps (OEIPs) of the commonly used anesthetic drug bupivacaine. Bupivacaine is delivered to dorsal root ganglion (DRG) neurons in vitro. DRG neurons are a good proxy for pain studies as they are responsible for relaying ascending sensory signals from nociceptors (pain receptors) in the peripheral nervous system to the central nervous system. Capillary based OEIPs are used due to their probe-like and free-standing form factor, ideal for interfacing with cells. By delivering bupivacaine with the OEIP and recording dose versus response (Ca2+ imaging), it is observed that only cells close to the OEIP outlet (≤75 µm) are affected (“anaesthetized”) and at concentrations up to 10s of thousands of times lower than with bulk/bolus delivery. These results demonstrate the first effective OEIP deliveryof a clinically approved and widely used analgesic pharmaceutical, and thus are a major translational milestone for this technology. © 2023 The Authors.
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| 5. |
- Smittenberg, Rienk H., et al.
(författare)
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Climate sensitive ecosystem carbon dynamics along the soil chronosequence of the damma glacier forefield, Switzerland
- 2012
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 18:6, s. 1941-1955
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Tidskriftsartikel (refereegranskat)abstract
- We performed a detailed study on the carbon build-up over the 140-year-long chronosequence of the Damma glacier forefield, Switzerland, to gain insights into the organic carbon dynamics during the initial stage of soil formation and ecosystem development. We determined soil carbon and nitrogen contents and their stable isotopic compositions, as well as molecular-level composition of the bulk soils, and recalcitrance parameters of carbon in different fractions. The chronosequence was divided into three age groups, separated by small end moraines that resulted from two glacier re-advances. The net ecosystem carbon balance (NECB) showed an exponential increase over the last decades, with mean annual values that range from 100gCm-2yr-1 in the youngest part to over 300gCm-2yr-1 in a 6080years old part. However, over the entire 140-year chronosequence, the NECB is only 20gCm-2yr-1, similar to results of other glacier forefield studies. The difference between the short- and long-term NECB appears to be caused by reductions in ecosystem carbon (EC) accumulation during periods with a colder climate. We propose that two complementary mechanisms have been responsible: 1) Reductions in net primary productivity down to 50% below the long-term mean, which we estimated using reconstructed effective temperature sums. 2) Disturbance of sites near the terminus of the re-advanced glacier front. Stabilization of soil organic matter appeared to play only a minor role in the coarse-grained forefield. We conclude that the forefield ecosystem, especially primary productivity, reacts rapidly to climate changes. The EC gained at warm periods is easily lost again in a cooling climate. Our conclusions may also be valid for other high mountain ecosystems and possibly arctic ecosystems.
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