39 research outputs found

    A Framework for Automated Supraglacial Lake Detection and Depth Retrieval in ICESat-2 Photon Data Across the Greenland and Antarctic Ice Sheets

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    Supraglacial lakes on the ice sheets have been linked to ice shelf collapse in Antarctica and accelerated flow of grounded ice in Greenland. However, it is difficult to quantify the impact of supraglacial lakes on ice dynamics accurately enough to predict their contribution to future mass loss and sea level rise. This is largely because ice-sheet-wide assessments of meltwater volumes rely on models that are poorly constrained due to a lack of accurate depth measurements. Various recent case studies have demonstrated that accurate supraglacial lake depths can be obtained from ICESat-2’s ATL03 photon-level data product. ATL03 comprises hundreds of terabytes of unstructured point cloud data, which has made it challenging to use this bathymetric capability at scale. Here, we present two new algorithms – Flat Lake and Underlying Ice Detection (FLUID) and Surface Removal and Robust Fit (SuRFF) – which together provide a fully automated and scalable method for lake detection and depth determination from ATL03 data, and establish a framework for its large-scale implementation using distributed high-throughput computing. We report FLUID/SuRFF algorithm performance over two regions known to have significant surface melt – Central West Greenland and Amery Ice Shelf catchment in East Antarctica – during two melt seasons. FLUID/SuRFF reveals a total of 1249 lakes up to 25 m deep, with more water during higher melt years. In absence of ground truth data, manual annotation of test data suggests that our method reliably detects melt lakes whenever a bathymetric signal is discernible, and estimates water depths with a mean absolute error of 0.28 m. These results imply that our proposed framework has the potential to generate a comprehensive data product of accurate meltwater depths across both ice sheets

    Design with Sound: The Relevance of Sound in VR as an Immersive Design Tool for Landscape Architecture

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    Funding Information: This book follows the findings of the book Open Innovation in the Financial Services, published in 2009 by Springer, grounded on my doctoral research with the aim to explore how banks can gain competitive advantage with the open innovation approach and how this can be used for realizing strategic advantage. At that time, collaborative and open approaches to service innovation were considered by some industries as business trends but not covered in the literature. One critique, though, was the almost exclusive focus on industrial research. I remember well, when my supervisor professor Ken Starkey asked me, after a status meeting, why I don’t examine the paper by Henry Chesbrough “The era of open innovation”, the first article on that topic, published in the Sloan Management Review in Spring 2003. As his studies came from manufacturing and technology firms, I wanted to test these concepts for the services. As a result, I shifted the focus of my research towards open innovation in the banking industry and applied interpretivism as philosophical assumption with a theory to be tested with empirical data. I was granted a scholarship award for an excellent research idea from the business school, in addition to funding, received from the Economic and Social Research Council of the United Kingdom. After completion of my thesis, The Transition to Open Innovation: A Case Study in the Banking Industry in 2005, I acknowledged that management research should be practice oriented and appropriate for managers or about managers and social organisations. Combined with my professional experiences, gained as a banker, I transformed my thesis into a more practice-oriented book, published in 2009. I considered open innovation as the best way for creating value for operational excellence and profitable growth in the financial services. Publisher Copyright: © 2023, VDE VERLAG GMBH. All rights reserved.Sound in landscape architecture commonly focuses on noise. In design or planning process sound rarely plays a holistic and essential role. This is partly due to the need for more tools to address the complex topic. This research introduces novel opportunities to explore the importance of sound as an immersive design parameter in landscape architecture and planning within Virtual Reality (VR). The project investigates immersive sound experiences by presenting sonic data in audible form. A VR app was constructed from multiple on-location spatial sound recordings. Within a test case, the application was used by participants, comparing a conventional design approach with the proposed VR methodology. The outcome of the test clearly shows the importance of integrating sound in an audible form to enhance the comprehensive understanding of space. The paper will focus on the discussion of the technical as well as the design-specific components.Peer reviewe

    Maximizing Cache Hit Ratios by Variance Reduction

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    Sensory testing and topical capsaicin can characterize patients with rheumatoid arthritis

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    Background and objectives: Our study aimed at examining the long-time inflammatory effects of rheumatoid arthritis (RA) as chronic immune-mediated disease on pain sensation and neuropathy development compared to healthy subjects (HS). Methods: We used the quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain and Electroencephalography (EEG)–based contact heat evoked potentials (CHEPs) before and after topical capsaicin application. We recruited 16 RA patients in remission or low disease activity state (mean age: 59.38 years [± 10.18]) and 16 healthy subjects (mean age: 56.69 years [± 8.92]). Results: The application of capsaicin cream on the thigh provoked a stronger effect in HS for both mechanical and heat pain thresholds (MPT and HPT, resp.), according to the area under the receiver operation characteristic (AUROC) (HS: HPT: 0.8965, MPT: 0.7402; RA: HPT: 0.7012, MPT: 0.6113). We observed contrary effects regarding changes in CHEPs (HS: g*max =  − 0.65; RA patients: g*max = 0.72). Conclusion: As the overall effect of topical capsaicin application was higher in HS for QST, we suggest the existence of a sensitization of TRPV1 channels in RA patients caused by long-time chronical inflammation, despite a lack of clinical signs of inflammation due to adequate treatment. The effect in CHEPs probably uncovers neuropathic symptoms. The effect of topical capsaicin on HPTs and CHEPs can act as a marker for the extent of sensitization and the development of neuropathic symptoms. Further studies are needed to prove if our proposed method can act as a marker for the success of anti-inflammatory treatment

    Substrate specificity of human metallocarboxypeptidase D: Comparison of the two active carboxypeptidase domains

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    Metallocarboxypeptidase D (CPD) is a membrane-bound component of the trans-Golgi network that cycles to the cell surface through exocytic and endocytic pathways. Unlike other members of the metallocarboxypeptidase family, CPD is a multicatalytic enzyme with three carboxypeptidase-like domains, although only the first two domains are predicted to be enzymatically active. To investigate the enzymatic properties of each domain in human CPD, a critical active site Glu in domain I and/or II was mutated to Gln and the protein expressed, purified, and assayed with a wide variety of peptide substrates. CPD with all three domains intact displays >50% activity from pH 5.0 to 7.5 with a maximum at pH 6.5, as does CPD with mutation of domain I. In contrast, the domain II mutant displayed >50% activity from pH 6.5–7.5. CPD with mutations in both domains I and II was completely inactive towards all substrates and at all pH values. A quantitative peptidomics approach was used to compare the activities of CPD domains I and II towards a large number of peptides. CPD cleaved C-terminal Lys or Arg from a subset of the peptides. Most of the identified substrates of domain I contained C-terminal Arg, whereas comparable numbers of Lys- and Arg-containing peptides were substrates of domain II. We also report that some peptides with C-terminal basic residues were not cleaved by either domain I or II, showing the importance of the P1 position for CPD activity. Finally, the preference of domain I for C-terminal Arg was validated through molecular docking experiments. Together with the differences in pH optima, the different substrate specificities of CPD domains I and II allow the enzyme to perform distinct functions in the various locations within the cell.This work was funded by the Spanish Ministry of Innovation and Competitiveness grants BIO2013-44973-R and BIO2016-78057-R (to FXA), by Plan Estatal grant number BIO2016-79960-R from the Spanish Ministry of Economy and Competitiveness (to JFR), and by grant R01-DA004494 from the United States’ National Institute of Health (to LDF).Peer Reviewe

    Parallelizable Microfluidic Platform to Model and Assess In Vitro Cellular Barriers: Technology and Application to Study the Interaction of 3D Tumor Spheroids with Cellular Barriers

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    Endothelial and epithelial cellular barriers play a vital role in the selective transport of solutes and other molecules. The properties and function of these barriers are often affected in case of inflammation and disease. Modelling cellular barriers in vitro can greatly facilitate studies of inflammation, disease mechanisms and progression, and in addition, can be exploited for drug screening and discovery. Here, we report on a parallelizable microfluidic platform in a multiwell plate format with ten independent cell culture chambers to support the modelling of cellular barriers co-cultured with 3D tumor spheroids. The microfluidic platform was fabricated by microinjection molding. Electrodes integrated into the chip in combination with a FT-impedance measurement system enabled transepithelial/transendothelial electrical resistance (TEER) measurements to rapidly assess real-time barrier tightness. The fluidic layout supports the tubeless and parallelized operation of up to ten distinct cultures under continuous unidirectional flow/perfusion. The capabilities of the system were demonstrated with a co-culture of 3D tumor spheroids and cellular barriers showing the growth and interaction of HT29 spheroids with a cellular barrier of MDCK cells
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