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Start Over Author "Lüthi A" Publisher elsevier b.v.
276 results on '"Lüthi A"'

14. Karst modelling challenge 1: Results of hydrological modelling

Author

Jeannin, Pierre-Yves, Artigue, Guillaume, Butscher, Christoph, Chang, Yong, Charlier, Jean-Baptiste, Duran, Lea, Gill, Laurence, Hartmann, Andreas, Johannet, Anne, Jourde, Hervé, Kavousi, Alireza, Liesch, Tanja, Liu, Yan, Lüthi, Martin, Malard, Arnauld, Mazzilli, Naomi, Pardo-Igúzquiza, Eulogio, Thiéry, Dominique, Reimann, Thomas, Schuler, Philip, Wöhling, Thomas, and Wunsch, Andreas

Published
2021
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15. Cytokine and lipid metabolome effects of low-dose acetylsalicylic acid in critically ill patients with systemic inflammation: a pilot, feasibility, multicentre, randomised, placebo-controlled trial

Author

Cioccari, Luca, Luethi, Nora, Duong, Thy, Ryan, Eileen, Cutuli, Salvatore L., Lloyd-Donald, Patryck, Eastwood, Glenn M., Peck, Leah, Young, Helen, Vaara, Suvi T., French, Craig J., Orford, Neil, Dwivedi, Jyotsna, Lankadeva, Yugeesh R., Bailey, Michael, Reid, Gavin E., and Bellomo, Rinaldo

Published
2020
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31. An adaptive smoothed particle hydrodynamics (SPH) scheme for efficient melt pool simulations in additive manufacturing.

Author

Lüthi, C., Afrasiabi, M., and Bambach, M.

Subjects
*HYDRODYNAMICS, *MARANGONI effect, *PARALLEL programming, *MELTING, *PHENOMENOLOGICAL theory (Physics), *INJECTION molding
Abstract

Smoothed particle hydrodynamics (SPH) is a well-developed mesh-free method that has proven highly efficient for mesoscopic additive manufacturing (AM) simulations. Nevertheless, all current three-dimensional SPH models in this ever-growing field of application are based on a uniform discretization size (i.e., single-resolution domain) and cannot exploit the computational efficiency of this method from an algorithmic point of view. In this work, we present a spatially fully-adaptive SPH scheme and apply it for the first time to simulate the melt pool behavior in laser powder bed fusion (LPBF) additive manufacturing. The implementation contains state-of-the-art numerical stabilization techniques to ensure the SPH stability and robustness, as well as all crucial physical phenomena, such as the recoil pressure, wetting, and Marangoni effects, to capture the melt pool dynamics in detail. Full spatial adaptivity is enabled by particle splitting and merging, where the spatial resolution can be refined and coarsened concurrently multiple times. As a result of this and a novel sorting algorithm, the code performs about 5x faster in powder-based AM applications, making it feasible to simulate multi-track LPBF processes within reasonable times without parallel computing for the first time. • First fully-adaptive SPH method for melt pool simulations in additive manufacturing. • Multiple levels of particle refinement and coarsening permitted in the model. • Novel sorting algorithm for an optimized multi-resolution cell-list organization. • Proposed multi-level adaptivity can save up to 80% of calculation times. • Simulating multi-track LPBF with SPH without parallel computing is feasible. [ABSTRACT FROM AUTHOR]

Published
2023
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41. Exceptional foraging plasticity in King Penguins (Aptenodytes patagonicus) from a recently established breeding site in Tierra del Fuego, Chile

Author

Alejandro Simeone, Klemens Pütz, Julieta Pedrana, Marco Flagg, Claudia Godoy, Juliana A. Vianna, Pablo García-Borboroglu, Benno Lüthi, and Camila Gherardi-Fuentes

Subjects
Range (biology), Diving, Climate Change, Sprattus, Foraging, Diving behavior, Aptenodytes patagonicus, Predation, Range expansion, Buceo, Tierra del Fuego, Chile, Ecology, Evolution, Behavior and Systematics, QH540-549.5, Diet, Dispersal, Foraging area, Trip duration, Nature and Landscape Conservation, Ecological niche, biology, Pingüinos Rey, Ecology, Comportamiento Animal, Pelagic zone, Ecología, biology.organism_classification, Spheniscidae, Fishery, Geography, Cambio Climático, Biological dispersal, Animal Behaviour, Aves
Abstract

Animals constantly test the borders of their own ecological niche and tend to expand their range, which is now additionally challenged by global climate change. Following human exploitation throughout the Southern Ocean in the 19th and the beginning of the 20th century, numbers of King Penguin breeding pairs have increased and former breeding sites have been re-colonized. Since 2010 a breeding colony became (re-)established at Bahía Inútil, Strait of Magellan, Tierra del Fuego, Chile. The aims of this study were to study the foraging ecology of King Penguins at this new breeding site, which is characterized by a set of different environmental variables as it is located within the confined environment of the Magellan Strait, more than 300 km from the open ocean. During the course of this study, thirty-two birds were successfully equipped with external devices that recorded 206 foraging trips by breeding and non-breeding birds. With one exception, all birds foraged throughout the year exclusively in the Magellan Strait with the main foraging areas located within 100 km from the colony. The diving activities of 15 King Penguins were recorded during 59 foraging trips, the deepest dive was 160 m and the longest dive lasted 6.75 mins. Based on a representative subsample of 3000 dives, mean dive depth was 32 ± 34 m and mean dive duration 117 ± 84 s. Accordingly, foraging trip durations throughout the year were significantly shorter than those recorded for conspecifics elsewhere. In accordance with these changes in foraging behavior, stomach contents from seven birds showed a mix of fish and squid, with Falkland sprats Sprattus fuegensis as the main prey item present in all samples. The implications of these behavioral adaptations are discussed with regard to this unusual confined foraging environment and predicted changes in the performance of King Penguins breeding elsewhere following global change. EEA Balcarce Fil: Pütz, Klemens. Antarctic Research Trust, Am Oste-Hamme-Kanal ; Alemania. Fil: García Borboroglu, Pablo. Global Penguin Society; Estados Unidos. Fil: García Borboroglu, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro para el Estudio de Sistemas Marinos; Argentina. Fil: Godoy, Claudia. Global Penguin Society; Estados Unidos. Fil: Godoy, Claudia. Parque Pingüino Rey; Chile. Fil: Flagg, Marco. Desert Star Systems, Estados Unidos. Fil: Pedrana, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Pedrana, Julieta. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Vianna, Juliana. Pontificia Universidad Católica de Chile. Departamento de Ecosistemas y Medio Ambiente; Chile. Fil: Simeone, Alejandro. Universidad Andrés Bello. Facultad de Ciencias de la Vida; Chile. Fil: Lüthi, Benno. Antarctic Research Trust; Suiza. Fil: Gherardi Fuentes, Camila. Universidad Andrés Bello. Facultad de Ciencias de la Vida; Chile.

Published
2021

42. Measurement Properties of ID-PALL, A New Instrument for the Identification of Patients With General and Specialized Palliative Care Needs.

Author

Teike Lüthi, Fabienne, Bernard, Mathieu, Vanderlinden, Katia, Ballabeni, Pierluigi, Gamondi, Claudia, Ramelet, Anne-Sylvie, Borasio, Gian Domenico, Teike Lüthi, F, Bernard, M, Vanderlinden, K, Ballabeni, P, Gamondi, C, Ramelet, A S, Borasio, G D, and Ballabeni, Pierrluigi

Subjects
*PALLIATIVE treatment, *PHYSICIANS, *CRONBACH'S alpha, *HOSPITALISTS, *PHYSICIAN services utilization, *CANCER patient care, *RESEARCH, *CROSS-sectional method, *RESEARCH methodology, *MEDICAL cooperation, *EVALUATION research, *PSYCHOMETRICS, *COMPARATIVE studies, *QUESTIONNAIRES, *LONGITUDINAL method, RESEARCH evaluation
Abstract

Context: To improve access to palliative care, identification of patients in need of general or specialized palliative care is necessary. To our knowledge, no available identification instrument makes this distinction. ID-PALL is a screening instrument developed to differentiate between these patient groups.Objective: To assess the structural and criterion validity and the inter-rater agreement of ID-PALL.Methods: In this multicenter, prospective, cross-sectional study, nurses and physicians assessed medical patients hospitalized for 2 to 5 days in two tertiary hospitals in Switzerland using ID-PALL. For the criterion validity, these assessments were compared to a clinical gold standard evaluation performed by palliative care specialists. Structural validity, internal consistency and inter-rater agreement were assessed.Results: 2232 patients were assessed between January and December 2018, 97% by nurses and 50% by physicians. The variances for ID-PALL G and S are explained by two factors, the first one explaining most of the variance in both cases. For ID-PALL G, sensitivity ranged between 0.80 and 0.87 and specificity between 0.56 and 0.59. ID-PALL S sensitivity ranged between 0.82 and 0.94, and specificity between 0.35 and 0.64. A cut-off value of 1 delivered the optimal values for patient identification. Cronbach's alpha was 0.78 for ID-PALL G and 0.67 for ID-PALL S. The agreement rate between nurses and physicians was 71.5% for ID-PALL G and 64.6% for ID-PALL S.Conclusion: ID-PALL is a promising screening instrument allowing the early identification of patients in need of general or specialized palliative care. It can be used by nurses and physicians without a specialized palliative care training. Further testing of the finalized clinical version appears warranted. [ABSTRACT FROM AUTHOR]

Published
2021
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46. Effects of aldosterone on the human placenta: Insights from placental perfusion studies.

Author

Mistry, Hiten D., Klossner, Rahel, Kallol, Sampada, Lüthi, Michael P., Moser, Ruedi, Schneider, Henning, Ontsouka, Edgar C., Kurlak, Lesia O., Mohaupt, Markus G., and Albrecht, Christiane

Abstract

Introduction: In pregnancy, aldosterone is linked to maternal plasma volume expansion, improved fetal and placental growth/angiogenesis and reduced maternal blood pressure. Aldosterone levels are low in women with pre-eclampsia. Given the placental growth properties of aldosterone in pregnancy, we hypothesised that increased aldosterone improves placental function ex vivo. We applied aldosterone in the dual human placenta perfusion model and analysed specific regulatory markers.Methods: A single cotyledon was perfused using a trimodal perfusion setup consisting of a control phase (CP; basic perfusion medium (BPM) alone) and two consecutive experimental phases (EP1/EP2; BPM supplemented with 1.5 x 10-9M and 1.5 x 10-7M aldosterone, respectively). CP and EP1/EP2 were conducted in closed circuits lasting 2 h each. Quality/time control perfusions using BPM alone were performed for 360 min to distinguish time-dependent effects from aldosterone-related effects. Perfusates were assessed for control parameters (pH/pO2/pCO2/glucose/lactate/creatinine/antipyrine). Maternal perfusates were analysed for placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), interleukin-10 (IL-10) and tumour necrosis factor-alpha (TNF-α) using ELISAs. mRNA expression of abovementioned factors was measured by qPCR in post-perfusion tissue.Results: Data from quality/time control perfusions indicated that TNF-α and IL-10 release continuously increased over time. Contrary, in the trimodal perfusion setup the application of aldosterone decreased TNF-α secretion (P < 0.05, EP1/EP2 vs CP, 120 min) and increased PlGF release (P < 0.05, EP1 vs CP, 90/120 min) into the maternal perfusates. mRNA expression followed similar trends, but did not reach significance.Discussion: Our ex vivo placental perfusion data suggest that increasing aldosterone promotes anti-inflammatory and pro-angiogenic factors, which could positively contribute to healthy pregnancy outcomes. [ABSTRACT FROM AUTHOR]

Published
2022
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