| 1. |
- Collins, Elin, et al.
(författare)
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Physicians' assessment of complications after gynecological surgery in Sweden : The GYNCOM survey
- 2023
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : John Wiley & Sons. - 0001-6349 .- 1600-0412. ; 102:11, s. 1479-1487
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Complications after gynecological surgery in Sweden are registered in the well-established Swedish National Quality Register of Gynecological Surgery, GynOp. The aim of this study was to analyze interrater reliability in assessing complications according to the methods in GynOp, and to explore physicians' perceptions of registering complications.Material and methods: A digital survey was sent to gynecologists and residents in gynecology in Sweden. Participating clinics were recruited through the Swedish network for national clinical studies in Obstetrics and Gynecology, SNAKS. Twenty fictional cases, intended to represent normal postoperative course, failure to cure, and varying degrees of complications, were developed by the research group. The clinical scenarios included abdominal and laparoscopic surgery of the uterus and adnexa, vaginal hysterectomies, as well as hysteroscopy. The respondents graded each case on the presence of a complication (yes/no). Type of complication, severity, and what action the complication required according to Clavien-Dindo was registered if a complication was acknowledged, according to the method in GynOp. Interrater reliability and the opinions of the respondents were presented descriptively. More than 80% of respondents making the same assessment was considered as agreement.Results: The response rate was 41%, with 104 responding physicians from 16 gynecological clinics. Type and severity of complication was considered relevant to register by 88% and 89% of respondents, respectively. Agreement on whether the case described a complication was >80% in 85% (17/20) of cases and agreement using the Clavien-Dindo classification was >90% in 80% (16/20) of cases. There was high agreement in assessments of classically severe complications, such as pulmonary embolism and ureteral damage, in both presence of complication and severity, as well as Clavien-Dindo (>90% for all methods). Cases with agreement <80% on whether the case described a complication were bordering between normal postoperative course and minor complication.Conclusions: This study provides validation for the methods used to register complications after gynecological surgery according to the GynOp register, including the use of Clavien-Dindo in gynecology. However, the results indicate a need to define what should be considered symptoms inherent to each type of surgery.
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| 2. |
- Darelius, Anders, 1977, et al.
(författare)
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Measurement of the velocity field and frictional properties of wet masses in a high shear mixer
- 2007
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Ingår i: Chemical Engineering Science. ; 62, s. 2366-2374
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Tidskriftsartikel (refereegranskat)abstract
- In order to develop predictive process models and to enhance process understanding in high shear granulation, there is an ongoing search for non-intrusive methods for measuring the wet mass velocities in the mixer. In this study a high speed CCD camera is used in combination with software for Particle Image Velocimetry (PIV) calculations to obtain information about the wet mass velocities. The focus has been on obtaining good spatial and angular resolution for the velocities along the glass bowl wall. In a Jenike shear cell, both internal and wall frictional properties have been measured and together with velocity data, this information is used for prediction of the impeller torque. It has been shown that the near wall velocities are strongly dependent on the coefficient of wall friction, which decreases during liquid addition. The decrease in the coefficient of wall friction results in increased wet mass velocities close to the bowl wall. It is also found that the wet mass velocity has a strong angular dependence, resulting in a high frequency pulsing bed behaviour which cannot be detected by visual inspection. The predictive impeller torque model developed by Knight et al. (2001) has been generalized to account for cohesive materials and with frictional and velocity data, the level of the impeller torque is well predicted. However, the model is based on crude assumptions regarding the velocity distribution and hence, it cannot capture the dynamics in the measured torque curve satisfactorily.
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| 3. |
- Ferraro, Mattia, et al.
(författare)
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Establishing the current relation between observed oxygen conditions and oxygen proxies in western Norwegian fjords
- 2022
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Ingår i: 14th International Palaeoceanography Congress (ICP), Bergen (Norway).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Recently, there have been alarming reports regarding the de-oxygenation of Norwegian fjords due to climate change. Warming coastal waters and a suggested decrease in the renewal frequency of the fjords’ deep, stagnant basin water have been linked to the reduced oxygen concentrations. The fjords are economically important to Norway, and the water quality is (of course) of uttermost importance to the local ecosystem. Here I present a new project, FJO2RD, which investigates recent changes in the physical forcing and the renewal frequency while utilising paleo records from sediment archives to provide information on natural variability in fjord oxygenation during the last ca. 400 years. New multi- and gravity cores will be obtained from two fjords, Masfjorden and Lurefjorden, in western Norway. The oxygenation history will be reconstructed based on benthic foraminiferal assemblages and geochemical analyses. The Mn/Ca ratio will be analysed to study the extent of hypoxic conditions and past oxygen dynamics, and the Ba/Ca ratio to study runoff variability and stratification. The stable carbon isotopes will infer remineralisation associated with the change in oxygen. Dissolved oxygen concentrations will further be quantified using a modified Behl dissolved oxygen index, which is a method that calculates changes in oxygen concentrations by using a weighted average for each oxygen category as 0.1 mL/L for dysoxic, 0.5 mL/L for suboxic, and 1.5 mL/L for weakly hypoxic-oxic conditions. The results of these analyses will be used as the basis for my PhD-thesis
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| 4. |
- Ferraro, Mattia, et al.
(författare)
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Multi-century reconstruction of environmental conditions in Lurefjorden, Norway.
- 2024
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Ingår i: 24th Nordic Geological Winter Meeting, 10-12th Jan, 2024, Gothenburg, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Benthic foraminiferal assemblages are identified to reconstruct changes in environmental conditions over the last few centuries in Lurefjorden, a western Norwegian fjord. From ca. 1970 until present days the relative abundance of Brizalina skagerrakkensis, an efficient bio-indicator for organic matter fluxes, is enhanced relative to the preceding time interval. Hence, our results suggest that there is an increase of the organic matter within the Lurefjorden basin in the last 50 years. Over the same period, there is also an increase in the absolute abundance of agglutinated species, indicating lower oxygen concentration in the water. A lowering of the oxygen concentrations may have taken place as a response of a greater oxygen consumption caused by a higher organic matter supply in the water column. Accoridng to Aksnes (2009), Lurefjorden was subject to an increased freshening of Norwegian coastal waters (NCW), which has led to a decrease in sunlight penetration into the water column, affecting the oxygen levels and the behavior of marine life within the basin, between 1935 and 2007. Furthermore, we used diversity indices to study the ecological status of the area, showing significant growth in diversity, abundance, and richness within the benthic foraminiferal community over the past 50 years. Our observations highlight that an increase in the input of organic matter over the last century has led to a change in the benthic foraminifera community in the Lurefjorden basin.
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| 5. |
- Idahl, Annika, 1965-, et al.
(författare)
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HOPPSA update: changes in the study protocol of Hysterectomy and OPPortunistic SAlpingectomy, a registry-based randomized controlled trial
- 2023
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Ingår i: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The HOPPSA trial is a multi-center national registry-based randomized controlled trial to test the safety and effectiveness of performing opportunistic salpingectomy at hysterectomy to reduce the risk of epithelial ovarian cancer (EOC). The study protocol was first published in January 2019 and is available at . Here, we report amendments made to the study protocol since commencement of the trial.Changes in methods and analysis The primary outcomes analyses have been changed. (1) Complications will be analyzed using binomial generalized estimating equation (GEE) with log link function, while the unadjusted analyses according to Miettinen and Nurminen will be performed as a sensitivity analysis. (2) Absolute change in Menopause Rating Scale (MRS) will primarily be analyzed using a mixed effects model, adjusted for baseline MRS and center as a random effect. (3) Time to EOC will be analyzed using the mixed effects Cox regression model with center as random effect, while the unadjusted log-rank test will be performed as a sensitivity analysis.The primary outcome Complications will be based solely on the specific assessment in the GynOp quality registry. The Clavien-Dindo classification will be evaluated as a secondary outcome.Furthermore, MRS is also measured three years postoperatively to better pinpoint the onset of menopausal symptoms.Discussion The changes to the protocol mainly concern the analyses of data. No changes to recruitment, randomization, intervention, or follow-up of primary outcomes have been made. An interim analysis during 2021 concluded that the study should continue until the target sample size is reached.
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| 6. |
- Silvano, Alessandro, et al.
(författare)
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Observing Antarctic Bottom Water in the Southern Ocean
- 2023
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Ingår i: Frontiers in Marine Science. - 2296-7745. ; 10
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Forskningsöversikt (refereegranskat)abstract
- Dense, cold waters formed on Antarctic continental shelves descend along the Antarctic continental margin, where they mix with other Southern Ocean waters to form Antarctic Bottom Water (AABW). AABW then spreads into the deepest parts of all major ocean basins, isolating heat and carbon from the atmosphere for centuries. Despite AABW's key role in regulating Earth's climate on long time scales and in recording Southern Ocean conditions, AABW remains poorly observed. This lack of observational data is mostly due to two factors. First, AABW originates on the Antarctic continental shelf and slope where in situ measurements are limited and ocean observations by satellites are hampered by persistent sea ice cover and long periods of darkness in winter. Second, north of the Antarctic continental slope, AABW is found below approximately 2 km depth, where in situ observations are also scarce and satellites cannot provide direct measurements. Here, we review progress made during the past decades in observing AABW. We describe 1) long-term monitoring obtained by moorings, by ship-based surveys, and beneath ice shelves through bore holes; 2) the recent development of autonomous observing tools in coastal Antarctic and deep ocean systems; and 3) alternative approaches including data assimilation models and satellite-derived proxies. The variety of approaches is beginning to transform our understanding of AABW, including its formation processes, temporal variability, and contribution to the lower limb of the global ocean meridional overturning circulation. In particular, these observations highlight the key role played by winds, sea ice, and the Antarctic Ice Sheet in AABW-related processes. We conclude by discussing future avenues for observing and understanding AABW, impressing the need for a sustained and coordinated observing system.
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| 7. |
- Steiger, Nadine, et al.
(författare)
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Intermittent Reduction in Ocean Heat Transport Into the Getz Ice Shelf Cavity During Strong Wind Events
- 2021
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 48:14
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Tidskriftsartikel (refereegranskat)abstract
- The flow of warm water toward the western Getz Ice Shelf along the Siple Trough, West Antarctica, is intermittently disrupted during short events of Winter Water deepening. Here we show, using mooring records, that these 5–10 days-long events reduced the heat transport toward the ice shelf cavity by 25% in the winter of 2016. The events coincide with strong easterly winds and polynya opening in the region, but the Winter Water deepening is controlled by non-local coastal Ekman downwelling rather than polynya-related surface fluxes. The thermocline depth anomalies are forced by Ekman downwelling at the northern coast of Siple Island and propagate to the ice front as a coastal trapped wave. During the events, the flow at depth does no longer continue along isobaths into the ice shelf cavity but aligns with the ice front.
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| 8. |
- Steiger, Nadine, et al.
(författare)
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The Dynamics of a Barotropic Current Impinging on an Ice Front
- 2022
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Ingår i: Journal of Physical Oceanography. - 0022-3670 .- 1520-0485. ; 52:12, s. 2957-2973
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Tidskriftsartikel (refereegranskat)abstract
- The vertical front of ice shelves represents a topographic barrier for barotropic currents that transport a considerable amount of heat toward the ice shelves. The blocking effect of the ice front on barotropic currents has recently been observed to substantially reduce the heat transport into the cavity beneath the Getz Ice Shelf in West Antarctica. We use an idealized numerical model to study the vorticity dynamics of an externally forced barotropic current at an ice front and the impact of ice shelf thickness, ice front steepness, and ocean stratification on the volume flux entering the cavity. Our simulations show that thicker ice shelves block a larger volume of the barotropic flow, in agreement with geostrophic theory. However, geostrophy breaks locally at the ice front, where relative vorticity and friction become essential for the flow to cross the discontinuity in water column thickness. The flow entering the cavity accelerates and induces high basal melt rates in the frontal region. Tilting the ice front, as undertaken in sigma-coordinate models, reduces this acceleration because the flow is more geostrophic. Viscous processes}typically exaggerated in low-resolution models}break the potential vorticity constraint and bring the flow deeper into the ice shelf cavity. The externally forced barotropic current can only enter the cavity if the stratification is weak, as strong vertical velocities are needed at the ice front to squeeze the water column beneath the ice shelf. If the stratification is strong, vertical velocities are suppressed and the barotropic flow is almost entirely blocked by the ice front.
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| 9. |
- Wåhlin, Anna, 1970, et al.
(författare)
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Ice front blocking of ocean heat transport to an Antarctic ice shelf
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 578, s. 568-571
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Tidskriftsartikel (refereegranskat)abstract
- Mass loss from the Antarctic Ice Sheet to the ocean has increased in recent decades, largely because the thinning of its floating ice shelves has allowed the outflow of grounded ice to accelerate. Enhanced basal melting of the ice shelves is thought to be the ultimate driver of change, motivating a recent focus on the processes that control ocean heat transport onto and across the seabed of the Antarctic continental shelf towards the ice. However, the shoreward heat flux typically far exceeds that required to match observed melt rates, suggesting that other critical controls exist. Here we show that the depth-independent (barotropic) component of the heat flow towards an ice shelf is blocked by the marked step shape of the ice front, and that only the depth-varying (baroclinic) component, which is typically much smaller, can enter the sub-ice cavity. Our results arise from direct observations of the Getz Ice Shelf system and laboratory experiments on a rotating platform. A similar blocking of the barotropic component may occur in other areas with comparable ice–bathymetry configurations, which may explain why changes in the density structure of the water column have been found to be a better indicator of basal melt rate variability than the heat transported onto the continental shelf. Representing the step topography of the ice front accurately in models is thus important for simulating ocean heat fluxes and induced melt rates.
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| 10. |
- Wåhlin, Anna, 1970, et al.
(författare)
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Subinertial Oscillations on the Amundsen Sea Shelf, Antarctica
- 2016
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Ingår i: Journal of Physical Oceanography. - 0022-3670. ; 46:9, s. 2573-2582
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Tidskriftsartikel (refereegranskat)abstract
- Mooring data from the western flank of Dotson Trough, Amundsen Sea shelf region, show the presence of barotropic oscillations with a period of 40-80 hours. The oscillations are visible in velocity, temperature, salinity and pressure, and are comparable to tides in magnitude. The period of the oscillations corresponds to topographic Rossby waves of low group velocity and wavelength about 40 km, i.e. the half-width of the channel. It is suggested that these resonant topographic Rossby waves cause the observed peak in the wave spectra. The observations show that sparse CTD data from this region should be treated with caution and need to be complemented with moorings or yo-yo stations in order to give a representative picture for the hydrography.
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