1. |
- Alfredsson, Hampus, et al.
(författare)
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Infrastructure modeling for large-scale introduction of electric aviation
- 2022
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Ingår i: 35th International Electric Vehicle Symposium and Exhibition (EVS35).
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Konferensbidrag (refereegranskat)abstract
- This paper presents the results of the MODELflyg research project funded by the Swedish Transport Administration to gain more knowledge about ground charging infrastructure demand for the electrification of air traffic. An integrated simulation model was developed including flight traffic data processing, modelling of battery electric aircraft performance, and charging simulations. Several different options are available to select specific air traffic flows of interest, including scheduling algorithms for electric aviation adapted timetables. Furthermore, a smart-charging algorithm was developed to lower peak power demand at each airport from simultaneous charging of multiple electric aircraft.
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2. |
- Bayane, Imane, et al.
(författare)
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Real-Time Crack Detection in Bridges Using Monitoring and Machine Learning-Verified with an Actual Damage Case
- 2023
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Ingår i: Structural Health Monitoring 2023: Designing SHM for Sustainability, Maintainability, and Reliability - Proceedings of the 14th International Workshop on Structural Health Monitoring. - : DEStech Publications. ; , s. 1636-1644
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Konferensbidrag (refereegranskat)abstract
- Detecting damage in bridges that present signs of deterioration or have exceeded the expected lifespan is critical for ensuring safety in service. This paper suggests an approach for real-time damage detection for such bridges through monitoring and machine learning algorithms, which serve as timely alarms for decision-making and subsequent damage identification. The approach involves five steps: monitoring, data collection, data separation, feature extraction, and anomaly detection in real-time. Monitoring is ensured by strain gauges, accelerometers, and a temperature sensor. Data collection is ensured at high frequency continuously to capture the dynamic effects of loading. Data separation is provided to classify monitoring data according to loading events, which is in the case of the study characterized by the bridge opening, the bridge closing, and train passages. Feature extraction is provided to characterize monitoring data for each loading event. Anomaly detection is performed by the Isolation Forest and the One-Class Support Vector Machine algorithms. The algorithms are implemented in real-time for each new event. The approach is illustrated in a full-scale post-damage case study of a steel-bascule-railway bridge, in service since 1916, with signs of corrosion and fatigue. The results demonstrate the ability of the approach to capture a cracking event in real-time. The Isolation Forest algorithm is found to be more robust for damage detection compared to the One-Class Support Vector Machine. It assigned high scores to the events occurring during and after the cracking, highlighting its ability to capture such incidents promptly. These findings have significant implications for bridge owners as they can identify damage in components in real time, enabling them to take timely measures such as traffic interruption and subsequent repairs.
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3. |
- Bröchner, Jan, 1948, et al.
(författare)
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Outsourcing facilities services: needs and practices of Swedish owners of commercial property
- 2004
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Ingår i: Proceedings CIB W70 Facilities Management and Maintenance International Symposium, Hong Kong, 7-8 December 2004. ; , s. 395-400
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Konferensbidrag (refereegranskat)abstract
- Why and how facilities services are outsourced is a question that continues to attract interest. The purpose of this study has been to investigate links between categories of property owners and their demand for packaged facilities services. The empirical part is based on questionnaire responses from 20 large owners of commercial property in Sweden, and on interviews with 11 of these owners. Owners are characterized by portfolio value, geographical spread of properties, investment horizon, core business, and average tenant size. Three owner segments are identified and tentatively labelled Building Managers, Active Asset Managers, and Passive Asset Managers. Their outsourcing policies and practices differ clearly.
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4. |
- Carlqvist, Jeanette, et al.
(författare)
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Minimal risk of contrast-induced kidney injury in a randomly selected cohort with mildly reduced GFR
- 2021
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 31:5, s. 3248-3257
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AKI/PC-AKI) have been observational, and mostly retrospective, often with patients undergoing non-enhanced CT as controls. This carries risk of inclusion bias that makes the true incidence of PC-AKI hard to interpret. Our aim was to determine the incidence of PC-AKI in a large, randomly selected cohort, comparing the serum creatinine (Scr) changes after contrast medium exposure with the normal intraindividual fluctuation in Scr. Methods: In this prospective study of 1009 participants (age 50–65 years, 48% females) in the Swedish CArdioPulmonary bioImage Study (SCAPIS), with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min, all received standard dose intravenous iohexol at coronary CT angiography (CCTA). Two separate pre-CCTA Scr samples and a follow-up sample 2–4 days post-CCTA were obtained. Change in Scr was statistically analyzed and stratification was used in the search of possible risk factors. Results: Median increase of Scr post-CCTA was 0–2 μmol/L. PC-AKI was observed in 12/1009 individuals (1.2%) according to the old ESUR criteria (> 25% or > 44 μmol/L Scr increase) and 2 individuals (0.2%) when using the updated ESUR criteria (≥ 50% or ≥ 27 μmol/L Scr increase). Possible risk factors (e.g., diabetes, age, eGFR, NSAID use) did not show increased risk of developing PC-AKI. The mean effect of contrast media on Scr did not exceed the intraindividual Scr fluctuation. Conclusions: Iohexol administration to a randomly selected cohort with mildly reduced eGFR is safe, and PC-AKI is very rare, occurring in only 0.2% when applying the updated ESUR criteria. Key Points: • Iohexol administration to a randomly selected cohort, 50–65 years old with mildly reduced eGFR, is safe and PC-AKI is very rare. • Applying the updated ESUR PC-AKI criteria resulted in fewer cases, 0.2% compared to 1.2% using the old ESUR criteria in this cohort with predominantly mild reduction of renal function. • The mean effect of CM on Scr did not exceed the intraindividual background fluctuation of Scr, regardless of potential risk factors, such as diabetes or NSAID use in our cohort of 1009 individuals.
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5. |
- Ercan, Ayse Bahar, et al.
(författare)
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Clinical and biological landscape of constitutional mismatch-repair deficiency syndrome: an International Replication Repair Deficiency Consortium cohort study.
- 2024
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Ingår i: The Lancet Oncology. - 1470-2045. ; 25:5, s. 668-682
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Tidskriftsartikel (refereegranskat)abstract
- Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare and aggressive cancer predisposition syndrome. Because a scarcity of data on this condition contributes to management challenges and poor outcomes, we aimed to describe the clinical spectrum, cancer biology, and impact of genetics on patient survival in CMMRD.In this cohort study, we collected cross-sectional and longitudinal data on all patients with CMMRD, with no age limits, registered with the International Replication Repair Deficiency Consortium (IRRDC) across more than 50 countries. Clinical data were extracted from the IRRDC database, medical records, and physician-completed case record forms. The primary objective was to describe the clinical features, cancer spectrum, and biology of the condition. Secondary objectives included estimations of cancer incidence and of the impact of the specific mismatch-repair gene and genotype on cancer onset and survival, including after cancer surveillance and immunotherapy interventions.We analysed data from 201 patients (103 males, 98 females) enrolled between June 5, 2007 and Sept 9, 2022. Median age at diagnosis of CMMRD or a related cancer was 8·9 years (IQR 5·9-12·6), and median follow-up from diagnosis was 7·2 years (3·6-14·8). Endogamy among minorities and closed communities contributed to high homozygosity within countries with low consanguinity. Frequent dermatological manifestations (117 [93%] of 126 patients with complete data) led to a clinical overlap with neurofibromatosis type 1 (35 [28%] of 126). 339 cancers were reported in 194 (97%) of 201 patients. The cumulative cancer incidence by age 18 years was 90% (95% CI 80-99). Median time between cancer diagnoses for patients with more than one cancer was 1·9 years (IQR 0·8-3·9). Neoplasms developed in 15 organs and included early-onset adult cancers. CNS tumours were the most frequent (173 [51%] cancers), followed by gastrointestinal (75 [22%]), haematological (61 [18%]), and other cancer types (30 [9%]). Patients with CNS tumours had the poorest overall survival rates (39% [95% CI 30-52] at 10 years from diagnosis; log-rank p<0·0001 across four cancer types), followed by those with haematological cancers (67% [55-82]), gastrointestinal cancers (89% [81-97]), and other solid tumours (96% [88-100]). All cancers showed high mutation and microsatellite indel burdens, and pathognomonic mutational signatures. MLH1 or MSH2 variants caused earlier cancer onset than PMS2 or MSH6 variants, and inferior survival (overall survival at age 15 years 63% [95% CI 55-73] for PMS2, 49% [35-68] for MSH6, 19% [6-66] for MLH1, and 0% for MSH2; p<0·0001). Frameshift or truncating variants within the same gene caused earlier cancers and inferior outcomes compared with missense variants (p<0·0001). The greater deleterious effects of MLH1 and MSH2 variants as compared with PMS2 and MSH6 variants persisted despite overall improvements in survival after surveillance or immune checkpoint inhibitor interventions.The very high cancer burden and unique genomic landscape of CMMRD highlight the benefit of comprehensive assays in timely diagnosis and precision approaches toward surveillance and immunotherapy. These data will guide the clinical management of children and patients who survive into adulthood with CMMRD.The Canadian Institutes for Health Research, Stand Up to Cancer, Children's Oncology Group National Cancer Institute Community Oncology Research Program, Canadian Cancer Society, Brain Canada, The V Foundation for Cancer Research, BioCanRx, Harry and Agnieszka Hall, Meagan's Walk, BRAINchild Canada, The LivWise Foundation, St Baldrick Foundation, Hold'em for Life, and Garron Family Cancer Center.
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6. |
- Fahlman, Åsa, et al.
(författare)
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Oxygen supplementation in anesthetized brown bears (Ursus arctos) - how low can you go?
- 2014
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Ingår i: Journal of Wildlife Diseases. - : Wildlife Disease Association. - 0090-3558 .- 1943-3700. ; 50, s. 574-581
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxemia is anticipated during wildlife anesthesia and thus should be prevented. We evaluated the efficacy of low flow rates of supplemental oxygen for improvement of arterial oxygenation in anesthetized brown bears (Ursus arctos). The study included 32 free-ranging brown bears (yearlings, subadults, and adults; body mass 12-250 kg) that were darted with medetomidine-zolazepam-tiletamine (MZT) from a helicopter in Sweden. During anesthesia, oxygen was administered intranasally from portable oxygen cylinders at different flow rates (0.5-3 L/min). Arterial blood samples were collected before (pre-O-2), during, and after oxygen therapy and immediately processed with a portable analyzer. Rectal temperature, respiratory rate, heart rate, and pulse oximetry-derived hemoglobin oxygen saturation were recorded. Intranasal oxygen supplementation at the evaluated flow rates significantly increased the partial pressure of arterial oxygen (PaO2) from pre-O-2 values of 9.1 +/- 1.3 (6.3-10.9) kPa to 20.4 +/- 6.8 (11.1-38.7) kPa during oxygen therapy. When oxygen therapy was discontinued, the PaO2 decreased to values not significantly different from the pre-O-2, values. In relation to the body mass of the bears, the following oxygen flow rates are recommended: 0.5 L/min to bears <51 kg, 1 L/min to bears 51-100 kg, 2 L/min to bears 101-200 kg, and 3 L/min to bears 201-250 kg. In conclusion, low flow rates of intranasal oxygen were sufficient to improve arterial oxygenation in brown bears anesthetized with MZT. Because hypoxemia quickly recurred when oxygen was discontinued, oxygen supplementation should be provided continuously throughout anesthesia.
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7. |
- Fahlman, Åsa, et al.
(författare)
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Physiologic Evaluation of Capture and Anesthesia with Medetomidine–Zolazepam–Tiletamine in Brown Bears (Ursus arctos)
- 2011
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Ingår i: Journal of Zoo and Wildlife Medicine. - : American Association of Zoo Veterinarians. - 1042-7260 .- 1937-2825. ; 42, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Physiologic variables during anesthesia with medetomidine-zolazepam-tiletamine were evaluated in 52 free-ranging brown bears (Ursus arctos) darted from a helicopter and in six captive brown bears darted at a zoo. During anesthesia, rectal temperature, respiratory rate, heart rate, and pulse oximetry derived hemoglobin oxygen saturation were recorded. Arterial blood samples were collected and immediately analyzed for evaluation of pulmonary gas exchange, acid base status, and selected hematologic and plasma variables. At the end of anesthesia, atipamezole was administered intramuscularly at five times the medetomidine dose. Capture-induced hyperthermia and lactic acidemia were documented in free-ranging bears. Hypoxemia during anesthesia was documented in both free-ranging and captive bears. In free-ranging bears, rectal temperature, heart rate, lactate, hematocrit, and hemoglobin decreased significantly during anesthesia, whereas partial pressure of arterial carbon dioxide, pH, potassium, and glucose increased. Yearlings had a significantly higher heart rate, pH, base excess, bicarbonate, and glucose, and had a significantly lower rectal temperature, sodium, hematocrit, and hemoglobin when compared with subadult and adult brown bears. In conclusion, alterations in pulmonary gas exchange and acid base status in brown bears during anesthesia with medetomidine zolazepam tiletamine with the doses and capture methods used in this study were identified. Oxygen supplementation is recommended to counteract hypoxemia during anesthesia.
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8. |
- Fahlman, Åsa, et al.
(författare)
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TREATMENT OF HYPOXEMIA DURING ANESTHESIA OF BROWN BEARS (URSUS ARCTOS)
- 2010
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Ingår i: Journal of Zoo and Wildlife Medicine. - : American Association of Zoo Veterinarians. - 1042-7260 .- 1937-2825. ; 41, s. 161-164
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Tidskriftsartikel (refereegranskat)abstract
- This study assessed whether arterial oxygenation could be increased by treatment with intranasal oxygen supplementation in brown bears (Ursus arctos) with hypoxemia during anesthesia with medetomidine-zolazepam-tiletamine. Arterial blood samples were collected anaerobically from the femoral artery before and during oxygen supplementation. An oxygen flow rate of 2-5 L/min administered intranasally to brown bears weighing 12-120 kg markedly increased arterial oxygenation. Intranasal oxygen supplementation proved to be a simple and efficient method for treatment of hypoxemia in anesthetized bears.
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9. |
- Fomalont, E. B., et al.
(författare)
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THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW
- 2015
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 808:1
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Tidskriftsartikel (refereegranskat)abstract
- A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to similar to 15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from 2014 September to late November, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C 138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at similar to 350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.
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10. |
- Gobrecht, David, et al.
(författare)
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Bottom-up dust nucleation theory in oxygen-rich evolved stars: II. Magnesium and calcium aluminate clusters
- 2023
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 680
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Tidskriftsartikel (refereegranskat)abstract
- Context. Spinel (MgAl2O4) and krotite (CaAl2O4) are alternative candidates to alumina (Al2O3) as primary dust condensates in the atmospheres of oxygen-rich evolved stars. Moreover, spinel was proposed as a potential carrier of the circumstellar 13 μm feature. However, the formation of nucleating spinel clusters is challenging; in particular, the inclusion of Mg constitutes a kinetic bottleneck. Aims. We aim to understand the initial steps of cosmic dust formation (i.e. nucleation) in oxygen-rich environments using a quantum-chemical bottom-up approach. Methods. Starting with an elemental gas-phase composition, we constructed a detailed chemical-kinetic network that describes the formation and destruction of magnesium-, calcium-, and aluminium-bearing molecules as well as the smallest dust-forming (MgAl2O4)1 and (CaAl2O4)1 monomer clusters. Different formation scenarios with exothermic pathways were explored, including the alumina (Al2O3) cluster chemistry studied in Paper I of this series. The resulting extensive network was applied to two model stars, a semi-regular variable and a Mira-type star, and to different circumstellar gas trajectories, including a non-pulsating outflow and a pulsating model. We employed global optimisation techniques to find the most favourable (MgAl2O4)n, (CaAl2O4)n, and mixed (MgxCa(1-x)Al2O4)n isomers, with n = 1- 7 and x∈[0..1], and we used high level quantum-chemical methods to determine their potential energies. The growth of larger clusters with n = 2- 7 is described by the temperature-dependent Gibbs free energies. Results. In the considered stellar outflow models, spinel clusters do not form in significant amounts. However, we find that in the Mira-type non-pulsating model CaAl2O3(OH)2, a hydroxylated form of the calcium aluminate krotite monomer forms at abundances as large as 2 × 10-8 at 3 stellar radii, corresponding to a dust-to-gas mass ratio of 1.5 × 10-6. Moreover, we present global minimum (GM) candidates for (MgAl2O4)n and (CaAl2O4)n, where n = 1- 7. For cluster sizes n = 3- 7, we find new, hitherto unreported GM candidates. All spinel GM candidates found are energetically more favourable than their corresponding magnesium-rich silicate clusters with an olivine stoichiometry, namely (Mg2SiO4)n. Moreover, calcium aluminate clusters, (CaAl2O4)n, are more favourable than their Mg-rich counterparts; the latter show a gradual enhancement in stability when Mg atoms are substituted step by step with Ca. Conclusions. Alumina clusters with a dust-to-gas mass ratio of the order of 10-4 remain the favoured seed particle candidate in our physico-chemical models. However, CaAl2O4 could contribute to stellar dust formation and the mass-loss process. In contrast, the formation of MgAl2O4 is negligible due to the low reactivity of the Mg atom.
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