| 1. |
- Hedberg, Jakob, et al.
(författare)
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Randomized controlled trial of nasogastric tube use after esophagectomy : study protocol for the kinetic trial
- 2024
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Ingår i: Diseases of the esophagus. - : John Wiley & Sons. - 1120-8694 .- 1442-2050. ; 37:6
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Tidskriftsartikel (refereegranskat)abstract
- Esophagectomy is a complex and complication laden procedure. Despite centralization, variations in perioparative strategies reflect a paucity of evidence regarding optimal routines. The use of nasogastric (NG) tubes post esophagectomy is typically associated with significant discomfort for the patients. We hypothesize that immediate postoperative removal of the NG tube is non-inferior to current routines. All Nordic Upper Gastrointestinal Cancer centers were invited to participate in this open-label pragmatic randomized controlled trial (RCT). Inclusion criteria include resection for locally advanced esophageal cancer with gastric tube reconstruction. A pretrial survey was undertaken and was the foundation for a consensus process resulting in the Kinetic trial, an RCT allocating patients to either no use of a NG tube (intervention) or 5 days of postoperative NG tube use (control) with anastomotic leakage as primary endpoint. Secondary endpoints include pulmonary complications, overall complications, length of stay, health related quality of life. A sample size of 450 patients is planned (Kinetic trial: https://www.isrctn.com/ISRCTN39935085). Thirteen Nordic centers with a combined catchment area of 17 million inhabitants have entered the trial and ethical approval was granted in Sweden, Norway, Finland, and Denmark. All centers routinely use NG tube and all but one center use total or hybrid minimally invasive-surgical approach. Inclusion began in January 2022 and the first annual safety board assessment has deemed the trial safe and recommended continuation. We have launched the first adequately powered multi-center pragmatic controlled randomized clinical trial regarding NG tube use after esophagectomy with gastric conduit reconstruction.
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| 2. |
- Lindberg, Fredrik, 1974, et al.
(författare)
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Observations and modelling of mosquito prevalence within urban areas – A case study from Uppsala, Sweden
- 2024
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Ingår i: Urban Ecosystems. - 1083-8155 .- 1573-1642. ; 27, s. 1191-1205
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Tidskriftsartikel (refereegranskat)abstract
- Urban green–blue infrastructure (GBI) can provide important benefits to urban residents but may also affect mosquito abundance, with associated negative nuisance and infection transmission impacts. This study addresses important knowledge and quantification gaps for the relationships between mosquito prevalence and GBI features within cities. This is done for the city of Uppsala in Sweden as an urban case example, where mosquitos were captured and ambient air temperature and humidity were observed at seven different locations in the summer of 2022. A weighted multi-critera analysis (WMCA) model was developed based on relevant open data and open tools for resolving the mosquito (Culex pipiens) variations based on geographical variables, such as land cover/use, leaf area index, and building and green (vegetation) area fractions, within the city. The results show a clear relationship between mosquito prevalence and green-area fraction (of grass and trees), indicating that urban GBI extension can enhance mosquito prevalence, with possible associated negative impacts. This relationship is supported directly by data, showing significantly higher mosquito prevalence with higher ambient humidity, which in turn is related to larger green-area fraction. The developed WMCA model emerges as a promising tool, e.g., for urban development planning that needs to account for and seek relevant trade-off balances between positive and negative effects of urban GBI changes.
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| 3. |
- Bernard, Jérémy, 1989, et al.
(författare)
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URock 2023a: an open-source GIS-based wind model for complex urban settings
- 2023
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Ingår i: Geoscientific Model Development. - 1991-959X .- 1991-9603. ; 16:20, s. 5703-5727
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Tidskriftsartikel (refereegranskat)abstract
- URock 2023a is an open-source diagnostic model dedicated to wind field calculation in urban settings. It is based on a quick method initially proposed by and already implemented in the proprietary software QUIC-URB. First, the model method is described as well as its implementation in the free and open-source geographic information system called QGIS. Then it is evaluated against wind tunnel measurements and QUIC-URB simulations for four different building layouts plus one case with an isolated tree. The correlation between URock and QUIC-URB is high, and URock reproduces the spatial variation of the wind speed observed in the wind tunnel experiments quite well, even in complex settings. However, sources of improvements, which are applicable for both URock and QUIC-URB, are highlighted. URock and QUIC-URB overestimate the wind speed downstream of the upwind edges of wide buildings and also downstream of isolated tree crowns. URock 2023a is available via the Urban Multiscale Environment Predictor (UMEP), a city-based climate service tool designed for researchers and service providers presented as a plug-in for QGIS. The model, data, and scripts used to write this paper can be freely accessed at 10.5281/zenodo.7681245 .
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| 4. |
- Blankenburg, Malte, et al.
(författare)
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Revealing Precipitate Development During Hot Rolling and Cooling of a Ti–Nb Micro-Alloyed High Strength Low-Alloy Steel through X-Ray Scattering
- 2023
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Ingår i: Advanced Engineering Materials. - : Wiley. - 1438-1656 .- 1527-2648. ; 25:9
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Tidskriftsartikel (refereegranskat)abstract
- High-energy synchrotron X-ray small-angle scattering (SAXS) is used to study the precipitate development during hot rolling and cooling of a commercial Ti–Nb micro-alloyed, high-strength, low-alloy (HSLA) steel. To study precipitation during hot rolling conditions, Gleeble and dilatometer trials are made. Samples are then studied at room temperature using SAXS in conjunction with transmission electron microscopy (TEM). TEM is used to determine the morphology and composition of the precipitates, whilst both TEM and SAXS are used to study the particle sizes. One major advantage with high-energy SAXS is the ability to make measurements after a minimum of sample preparation and in transmission geometry, as opposed to just at prepared surfaces, plus the possibility to determine volume fractions of the precipitates. The measurements show that after deformation at high temperature, particle coarsening occurs and the volume fraction of precipitates increases after holding for 20 s at 900 °C which confirms strain-induced precipitation at finishing rolling conditions. The measurements show that holding at 600 or 650 °C for one hour gives a larger volume fraction of nanosized particles. Coiling simulations with slow cooling from 600 to 470 °C show coarsening of particles and an increase in the volume fraction of the smaller particles compared to holding at a constant temperature.
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| 5. |
- Wallenberg, Nils, 1986, et al.
(författare)
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An anisotropic parameterization scheme for longwave irradiance and its impact on radiant load in urban outdoor settings
- 2023
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Ingår i: International Journal of Biometeorology. - : Springer Science and Business Media LLC. - 0020-7128 .- 1432-1254. ; 67, s. 633-47
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Tidskriftsartikel (refereegranskat)abstract
- A robust representation of the radiative properties in complex urban settings is important for accurate estimations of radiant load. Here, we present a new parameterization scheme in the SOlar and LongWave Environmental Irradiance Geometry (SOLWEIG) model that partitions the upper hemisphere into 153 patches. Partitioning of the upper hemisphere enables determination if longwave irradiance originates from the sky, vegetation, sunlit building surfaces, or shaded building surfaces from each patch. Furthermore, a model for anisotropic sky longwave irradiance where emissivity increases with zenith angle is included. Comparisons between observations and simulations show high correlation, with R2 and RMSE for Tmrt of 0.94 and 4.6 °C, respectively, and R2 and RMSE for longwave radiation of 0.89 and 14.1 Wm−2, respectively. Simulations show that mean radiant temperature (Tmrt) can be up to 1.5 °C higher with an anisotropic sky compared to a uniform sky as an effect of higher radiant load on the vertical of a human when sky longwave irradiance increases with zenith angle. In comparisons of simulated Tmrt with the new parameterization and old parameterization schemes, previously overestimated Tmrt under trees (high sky obstruction, sky view factor (SVF)<0.3) can be decreased by up to 3 °C from more realistic estimations using the patches. Moreover, Tmrt close to sunlit walls (SVF~0.5) is increased by up to 2–3 °C from increased exposure to sunlit surfaces. Concluding, anisotropic sky longwave radiation and directionality of longwave radiation from different sources are important in estimations of Tmrt of humans in outdoor settings.
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| 6. |
- Wallenberg, Nils, 1986, et al.
(författare)
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Present and future heat stress of preschoolers in five Swedish cities
- 2023
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Ingår i: Climate Risk Management. - 2212-0963. ; 40
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Tidskriftsartikel (refereegranskat)abstract
- Heat stress can have negative effects on human wellbeing with morbidity and mortality as harmful consequences, especially in vulnerable groups, e.g. children, elderly and chronically ill. Children is for example at higher risk of dehydration and heat stroke compared to healthy adults. Furthermore, children attending preschools are endorsed to spend time outdoors and engaging in physical activities. Therefore, thermally comfortable preschool yards are detrimental to sustain safe environments where the children can continue their physically active play. Here we show that preschoolers in five Swedish cities, Malmö, Gothenburg, Stockholm, Östersund and Luleå, are exposed to heat stress on warm and clear days between May-August in preschool yards with insufficient shading, using three different thermal indices (COMFA, PET and UTCI). Furthermore, future number of heat stress days are evaluated using the SMHI RCA4 regional climate model from the EURO-CORDEX project, forced with six different global climate models. Results show that heat stress will increase under the RCP2.6, 4.5 and 8.5 climate change scenarios. In Malmö, Gothenburg and Stockholm number of days with heat stress all hours 09:00-15:00 while playing in a sunlit sandbox have doubled from approximately 10 to 20 days for 2071-2100 (RCP8.5) compared to 2008-2020. These numbers are even higher if active play, e.g. running, is performed, estimating to around two weeks in July alone by the end of the century. Without adaptation this is likely to have adverse effects on the health and learning of children. If the preschool yard, on the other hand, is shaded by trees, days with heat stress are almost entirely diminished, indicating the importance of trees in preschool yard design as a tool to mitigate heat stress.
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| 7. |
- Wallenberg, Nils, 1986, et al.
(författare)
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The effects of warm weather on children’s outdoor heat stress and physical activity in a preschool yard in Gothenburg, Sweden
- 2023
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Ingår i: International Journal of Biometeorology. - 0020-7128 .- 1432-1254. ; 67:12, s. 1927-40
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Tidskriftsartikel (refereegranskat)abstract
- Hot weather conditions can have negative impacts on the thermal comfort and physical activity of vulnerable groups such as children. The aim of this study is to analyze the effects of warm weather on 5-year-old children’s thermal comfort and physical activity in a preschool yard in Gothenburg, Sweden. In situ measurements were conducted for 1–1.5 h in the early afternoon on 8 days in May, June, and August of 2022. The thermal comfort and physical activity was estimated with GPS-tracks, heart rate monitors, and step counts and compared to observed weather conditions. Results show that physical activity decreases under warmer weather conditions, depicted by a decrease in distance moved, step counts, and highest registered pulse. Moreover, on warm days, the children avoid sunlit areas. For 50% or more of the time spent in sunlit areas, the children are exposed to cautious levels of heat. In shaded areas, on the other hand, the children are less exposed, with five out of 8 days having 50% or more of the time at neutral levels. The study demonstrates the importance of access to shaded areas in preschool yards where children can continue their active play while simultaneously maintaining a safe thermal status.
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| 8. |
- Zeng, Lily, et al.
(författare)
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Road surface temperature evaluated with streetview-derived parameters in a hot and humid megacity
- 2023
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Ingår i: Urban Climate. - 2212-0955. ; 51
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Tidskriftsartikel (refereegranskat)abstract
- This study explores the potential of a novel method that uses streetview-derived parameters to explain road surface temperature (RST) variations. The relationships between RST and streetview-derived parameters, including view factors (VFs), sunlit/shaded status, and sunlit hours, are investigated in an urban central district in a hot and humid climate. Thermal mapping of RST was conducted in 14 traverses at different times on a hot summer day and on both sides of the street canyon. The performances of streetview-derived parameters were also compared with commonly used urban morphological parameters. Results show that the correlations between RST and streetview-derived sky view factor (SVF) and green view factor (GVF) can reach 0.92 and − 0.93, respectively, at around 11:25. Building view factor (BVF) shows a weak correlation with RST and exhibits different directions of influence at different times of the day and in different types of routes. Correlations between streetview-derived VFs and RST are scale-dependent, varying by time of day and showing different patterns on the two sides of one canyon. The correlations between RST and traditional morphological parameters (BCR, FAR and meanH) are weaker than streetview-derived ones (sunlit hours, screen status, SVF and GVF). Multiple linear regressions show that streetview-derived view factors can explain 59% ∼ 82% of the spatial variation in daily maximum RST. The study highlights the potential of using streetview-derived parameters to predict RST.
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| 9. |
- Bäcklin, Oskar, 1991, et al.
(författare)
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Outdoor heat stress at preschools during an extreme summer in Gothenburg, Sweden - Preschool teachers’ experiences contextualized by radiation modelling
- 2022
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Ingår i: Multiple Nordic Geographies 9th Nordic Geographers Meeting 19th - 22nd of June 2022 Joensuu, Finland.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- With increasing urbanisation and climate change, heat stress issues are becoming increasingly important to consider in order to create sustainable urban environments worldwide. Heat affects all groups in society, although small children are especially vulnerable due to physiological factors as well as limitations in their everyday mobility. Therefore, it is crucial to ensure that outdoor areas used by children, such as preschools provide healthy safe thermal conditions. Trees are proven effective heat mitigating objects, as well as highly appreciated features of preschool yards for their aesthetic and pedagogical aspects. However, there is a large variation in the amount of trees at preschool yards which can prove to be problematic regarding thermal comfort and well-being for both children and preschool teachers today and in the future. Using a mixed-method approach consisting of 19 interviews with preschool teachers, and modelling outdoor thermal conditions on 440 preschool yards, the occurrence of heat stress in Gothenburg preschools during the heat wave of 2018 and its effects on preschools has been studied. One third of modelled preschool yards were found to have more than 50% of the preschool yard area exposed to strong heat stress during a warm and sunny summer days, implying children in many preschools have significantly less play area than current guidelines deem sufficient. Shading, which was found mainly provided by trees within preschool yards rather than from objects in surrounding areas, provide effective heat mitigation. Shading devices such as shade-sails were found prone to breakage and not providing sufficient shading. Thus, shading devices are not suggested as a long-term solution for heat mitigation at preschool yards. Interviews confirmed that excessive heat conditions at preschool yards cause tired, drowsy and overheated children as well as forcing the preschool to prioritise care over pedagogical activities. The results demonstrated that heat stress is a problem at many Gothenburg preschools, with difficulties in ensuring the well-being of children at many preschools as a consequence. The strong correlation found between amount of trees at preschool yards and less heat stress highlight the importance of trees for heat mitigation.
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| 10. |
- Claesson, Erik, et al.
(författare)
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Carbide Precipitation during Processing of Two Low-Alloyed Martensitic Tool Steels with 0.11 and 0.17 V/Mo Ratios Studied by Neutron Scattering, Electron Microscopy and Atom Probe
- 2022
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Ingår i: Metals. - Basel, Switzerland : MDPI AG. - 2075-4701. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Two industrially processed low-alloyed martensitic tool steel alloys with compositions Fe-0.3C-1.1Si-0.81Mn-1.5Cr-1.4Ni-1.1Mo-0.13V and Fe-0.3C-1.1Si-0.81Mn-1.4Cr-0.7Ni-0.8Mo-0.14V (wt.%) were characterized using small-angle neutron scattering (SANS), scanning electron microscopy (SEM), Scanning transmission electron microscopy (STEM), and atom probe tomography (APT). The combination of methods enables an understanding of the complex precipitation sequences that occur in these materials during the processing. Nb-rich primary carbides form at hot working, while Fe-rich auto-tempering carbides precipitate upon quenching, and cementite carbides grow during tempering when Mo-rich secondary carbides also nucleate and grow. The number density of Mo-rich carbides increases with tempering time, and after 24 h, it is two to three orders of magnitude higher than the Fe-rich carbides. A high number density of Mo-rich carbides is important to strengthen these low-alloyed tool steels through precipitation hardening. The results indicate that the Mo-rich secondary carbide precipitates are initially of MC character, whilst later they start to appear as M2C. This change of the secondary carbides is diffusion driven and is therefore mainly seen for longer tempering times at the higher tempering temperature of 600◦C.
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