| 11. |
- Hansson, Lars-Anders, et al.
(författare)
-
Food-chain length alters community responses to global change in aquatic systems
- 2013
-
Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 3, s. 228-233
-
Tidskriftsartikel (refereegranskat)abstract
- Synergies between large-scale environmental changes, such as climate change1 and increased humic content (brownification)2, will have a considerable impact on future aquatic ecosystems. On the basis of modelling, monitoring and experimental data, we demonstrate that community responses to global change are determined by food-chain length and that the top trophic level, and every second level below, will benefit from climate change, whereas the levels in between will suffer. Hence, phytoplankton, and thereby algal blooms, will benefit from climate change in three-, but not in two-trophic-level systems. Moreover, we show that both phytoplankton (resource) and zooplankton (consumer) advance their spring peak abundances similarly in response to a 3 °C temperature increase; that is, there is no support for a consumer/resource mismatch in a future climate scenario. However, in contrast to other taxa, cyanobacteria—known as toxin-producing nuisance phytoplankton3—benefit from a higher temperature and humic content irrespective of the food-chain composition. Our results are mirrored in natural ecosystems. By mechanistically merging present food-chain theory with large-scale environmental and climate changes, we provide a powerful framework for predicting and understanding future aquatic ecosystems and their provision of ecosystem services and water resources.
|
|
| 12. |
- Hansson, Lars-Anders, et al.
(författare)
-
Food-chain length alters community responses to global change in aquatic systems
- 2013
-
Ingår i: Nature Climate Change. - 1758-6798. ; 3:3, s. 228-233
-
Tidskriftsartikel (refereegranskat)abstract
- Synergies between large-scale environmental changes, such as climate change(1) and increased humic content (brownification)(2), will have a considerable impact on future aquatic ecosystems. On the basis of modelling, monitoring and experimental data, we demonstrate that community responses to global change are determined by food-chain length and that the top trophic level, and every second level below, will benefit from climate change, whereas the levels in between will suffer. Hence, phytoplankton, and thereby algal blooms, will benefit from climate change in three-, but not in two-trophic-level systems. Moreover, we show that both phytoplankton (resource) and zooplankton (consumer) advance their spring peak abundances similarly in response to a 3 degrees C temperature increase; that is, there is no support for a consumer/resource mismatch in a future climate scenario. However, in contrast to other taxa, cyanobacteria-known as toxin-producing nuisance phytoplankton(3)-benefit from a higher temperature and humic content irrespective of the food-chain composition. Our results are mirrored in natural ecosystems. By mechanistically merging present food-chain theory with large-scale environmental and climate changes, we provide a powerful framework for predicting and understanding future aquatic ecosystems and their provision of ecosystem services and water resources.
|
|
| 13. |
- Lagedal, Rickard, et al.
(författare)
-
Impaired Antibody Response Is Associated with Histone-Release, Organ Dysfunction and Mortality in Critically Ill COVID-19 Patients
- 2022
-
Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 11:12
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: the pathophysiologic mechanisms explaining differences in clinical outcomes following COVID-19 are not completely described. This study aims to investigate antibody responses in critically ill patients with COVID-19 in relation to inflammation, organ failure and 30-day survival. Methods: All patients with PCR-verified COVID-19 and gave consent, and who were admitted to a tertiary Intensive care unit (ICU) in Sweden during March-September 2020 were included. Demography, repeated blood samples and measures of organ function were collected. Analyses of anti-SARS-CoV-2 antibodies (IgM, IgA and IgG) in plasma were performed and correlated to patient outcome and biomarkers of inflammation and organ failure. Results: A total of 115 patients (median age 62 years, 77% male) were included prospectively. All patients developed severe respiratory dysfunction, and 59% were treated with invasive ventilation. Thirty-day mortality was 22.6% for all included patients. Patients negative for any anti-SARS-CoV-2 antibody in plasma during ICU admission had higher 30-day mortality compared to patients positive for antibodies. Patients positive for IgM had more ICU-, ventilator-, renal replacement therapy- and vasoactive medication-free days. IgA antibody concentrations correlated negatively with both SAPS3 and maximal SOFA-score and IgM-levels correlated negatively with SAPS3. Patients with antibody levels below the detection limit had higher plasma levels of extracellular histones on day 1 and elevated levels of kidney and cardiac biomarkers, but showed no signs of increased inflammation, complement activation or cytokine release. After adjusting for age, positive IgM and IgG antibodies were still associated with increased 30-day survival, with odds ratio (OR) 7.1 (1.5-34.4) and 4.2 (1.1-15.7), respectively. Conclusion: In patients with severe COVID-19 requiring intensive care, a poor antibody response is associated with organ failure, systemic histone release and increased 30-day mortality.
|
|
| 14. |
- Lundin, Margareta
(författare)
-
Aspects on Image Quality in Radiologic Evaluation of the Urinary Tract
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The focus of this document is on image quality as one of the factors fundamental for the diagnostic process. With the rising number of procedures and the trend towards more complicated examinations, urinary tract investigations was chosen in this work as a good clinical model for evaluation of the factors influencing image quality and of the ways of evaluating image quality.In paper I, a method is described for optimisation during the introduction of a new imaging system, with a focus on the maintenance of image quality relative to the older already optimised system. Image quality was assessed using the image criteria of the European guidelines for IVU with visual grading analysis. Equivalent image quality in image pairs was achieved at 30% of the dose. The CDRAD contrast-detail phantom makes it possible to find dose levels that give equal image quality using different imaging systems.In paper II, the influence of bowel purgation on image quality in urography is questioned. The aim of this study was to compare bowel purgation and two other preparation methods; dietary restrictions and no preparation at all. Image quality was assessed according to European Commission criteria for excretory urography. The effectiveness of bowel purgation and the amount of residual gas were scored separately. The results of our study show that the preparation methods are of equal value and further use of bowel purgation before excretory urography cannot be justified.In paper III, the image quality of the non-enhanced series is compared to a virtual noncontrast series obtained using two generations of dual-energy CT scanners and taking CT of the urinary tract as a model. The image quality of the VNC images was rated inferior to the single-energy variant for both scanners, the OR range being 11.5–67.3 for the Definition and 2.1–2.8 for the Definition Flash. Visual noise and overall quality were regarded as better with Flash than with Definition. Image quality of VNC images obtained with the new generation of DECT is still slightly inferior compared to native images.In paper IV, the accuracy of measurement of renal calculi in a dual-energy, virtual, nonenhanced-image series is compared to actual stone size and a single-energy image series in the phantom study. This study shows that detection of small stones is not reliable, despite better image quality, with the new DECT and that small stones will be missed with VNC imaging. With larger stones, the inherent measurement error with CT is magnified with VNC imaging.
|
|
| 15. |
- Persson, Anders, et al.
(författare)
-
Effects of enrichment on simple aquatic food webs
- 2001
-
Ingår i: American Naturalist. - : University of Chicago Press. - 0003-0147 .- 1537-5323. ; 157:6, s. 654-669
-
Tidskriftsartikel (refereegranskat)abstract
- Simple models, based on Lotka-Volterra types of interactions between predator and prey, predict that enrichment will have a destabilizing effect on populations and that equilibrium population densities will change at the top trophic level and every second level below. We experimentally tested these predictions in three aquatic food web configurations subjected to either high or low nutrient additions. The results were structured by viewing the systems as either food chains or webs and showed that trophic level biomass increased with enrichment, which contradicts food chain theory. However, within each trophic level, food web configuration affected the extent to which different functional groups responded to enrichment. By dividing trophic levels into functional groups, based on vulnerability to consumption, we were able to identify significant effects that were obscured when systems were viewed as food chains. The results support the prediction that invulnerable prey may stabilize trophic-level dynamics by replacing other, more vulnerable prey. Furthermore, the vulnerable prey, such as Daphnia and edible algae, responded as predicted by the paradox of enrichment hypothesis; that is, variability in population density increased with enrichment. Hence, by describing ecosystems as a matrix of food web interactions, and by recognizing the interplay between interspecific competition and predation, a more complete description of the ecosystem function was obtained compared to when species were placed into distinct trophic levels.
|
|
| 16. |
- Persson, Anders, et al.
(författare)
-
Effects of enrichment on simple aquatic food webs
- 2001
-
Ingår i: The American Naturalist. ; 157:6, s. 654-669
-
Tidskriftsartikel (refereegranskat)abstract
- Simple models, based on Lotka-Volterra types of interactions between predator and prey, predict that enrichment will have a destabilizing effect on
|
|
| 17. |
- Schwenke, Jörg, et al.
(författare)
-
Digital in-line holography on amplitude and phase objects prepared with electron beam lithography.
- 2012
-
Ingår i: Journal of Microscopy. - : Wiley. - 0022-2720. ; 247:2, s. 196-201
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the fabrication and characterization of amplitude and phase samples consisting of well defined Au or Al features formed on ultrathin silicon nitride membranes. The samples were manufactured using electron beam lithography, metallization and a lift-off technique, which allow precise lateral control and thickness of the metal features. The fabricated specimens were evaluated by conventional microscopy, atomic force microscopy and with the digital in-line holography set-up at the Lund Laser Centre. The latter uses high-order harmonic generation as a light source, and is capable of recovering both the shape and phase shifting properties of the samples. We report on the details of the sample production and on the imaging tests with the holography set-up.
|
|
| 18. |
- Söderberg, Stefan, et al.
(författare)
-
MEASURES OF WAIST AND HIP MODIFY SEX-SPECIFIC ASSOCIATIONS BETWEEN BODY MASS INDEX AND PREVALENCE OF CORONARY ARTERY CALCIFICATION IN OPPOSITE DIRECTIONS
- 2019
-
Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 13-13
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Obesity is associated with increased risk of cardiovascular disease. However, there is still a debate whether accumulation of fat in certain depots modifies this risk. Using data from the CArdioPulmonary bioImage Study (SCAPIS), we investigated if anthropometric measurements of obesity (waist and hip) modifies the risk of coronary artery calcification. Methods: In the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on coronary artery calcification score (CACS) and anthropometry were recorded and traditional cardiovascular risk factors were measured. Body mass index (BMI) was categorized as; <25, 25-30, 30-35 and >35 kg/m2 , quartiles of waist and hip circumferences were constructed within each BMI category and compared using the lowest quartile as reference. Results were adjusted for site, age, smoking and diabetes status. Results: Obesity (BMI >30 kg/m2 ) was found in 21.9% of men and in 20.5% of women. In both sexes the odds ratio (OR) for CACS >0 increased with increasing BMI categories: comparing <25 and >35 kg/m2 , OR = 2.1 (95% CI: 1.6-2.7) for men and OR = 1.4 (1.2-1.8) for women. In addition, increasing quartiles of waist significantly increased the prevalence of CACS >0 for men [p = 0.05; OR = 1.2 (1.0-1.4) for highest quartile] and women [p = 0.005; OR = 1.3 (1.1-1.5)] while increasing quartiles of hip significantly decreased the prevalence for men [p = 0.005; OR = 0.8 (0.6-0.9)] and women [p = 0.04; OR = 0.8 (0.7-0.9)]. Data on education level and physical activity did not affect the model. Conclusion: Increased BMI is associated with increased prevalence of coronary artery calcification and the distribution of fat modifies this risk. Our results suggest that gluteofemoral adipose tissue (hip) counteracts the negative effects associated with BMI and abdominal adipose tissue (waist).
|
|
| 19. |
- Östgren, Carl Johan, et al.
(författare)
-
Prevalence of atherosclerosis in individuals with prediabetes and diabetes compared to normoglycaemic individuals-a Swedish population-based study.
- 2023
-
Ingår i: Cardiovascular diabetology. - : BioMed Central (BMC). - 1475-2840. ; 22:1
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with type 2 diabetes have an increased risk of death and cardiovascular events and people with diabetes or prediabetes have been found to have increased atherosclerotic burden in the coronary and carotid arteries. This study will estimate the cross-sectional prevalence of atherosclerosis in the coronary and carotid arteries in individuals with prediabetes and diabetes, compared with normoglycaemic individuals in a large population-based cohort.The 30,154 study participants, 50-64 years, were categorized according to their fasting glycaemic status or self-reported data as normoglycaemic, prediabetes, and previously undetected or known diabetes. Prevalence of affected coronary artery segments, severity of stenosis and coronary artery calcium score (CACS) were determined by coronary computed tomography angiography. Total atherosclerotic burden was assessed in the 11 clinically most relevant segments using the Segment Involvement Score and as the presence of any coronary atherosclerosis. The presence of atherosclerotic plaque in the carotid arteries was determined by ultrasound examination.Study participants with prediabetes (n = 4804, 16.0%) or diabetes (n = 2282, 7.6%) had greater coronary artery plaque burden, more coronary stenosis and higher CACS than normoglycaemic participants (all, p < 0.01). Among male participants with diabetes 35.3% had CACS ≥ 100 compared to 16.1% among normoglycaemic participants. For women, the corresponding figures were 8.9% vs 6.1%. The prevalence of atherosclerosis in the coronary arteries was higher in participants with previously undetected diabetes than prediabetes, but lower than in patients with known diabetes. The prevalence of any plaque in the carotid arteries was higher in participants with prediabetes or diabetes than in normoglycaemic participants.In this large population-based cohort of currently asymptomatic people, the atherosclerotic burden in the coronary and carotid arteries increased with increasing degree of dysglycaemia. The finding that the atherosclerotic burden in the coronary arteries in the undetected diabetes category was midway between the prediabetes category and patients with known diabetes may have implications for screening strategies and tailored prevention interventions for people with dysglycaemia in the future.
|
|
| 20. |
- Ahmad, Irma, et al.
(författare)
-
High prevalence of persistent symptoms and reduced health-related quality of life 6 months after COVID-19
- 2023
-
Ingår i: Frontiers In Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The long-term sequelae after COVID-19 constitute a challenge to public health and increased knowledge is needed. We investigated the prevalence of self-reported persistent symptoms and reduced health-related quality of life (HRQoL) in relation to functional exercise capacity, 6 months after infection, and explored risk factors for COVID-19 sequalae.METHODS: This was a prospective, multicenter, cohort study including 434 patients. At 6 months, physical exercise capacity was assessed by a 1-minute sit-to-stand test (1MSTST) and persistent symptoms were reported and HRQoL was evaluated through the EuroQol 5-level 5-dimension (EQ-5D-5L) questionnaire. Patients with both persistent symptoms and reduced HRQoL were classified into a new definition of post-acute COVID syndrome, PACS+. Risk factors for developing persistent symptoms, reduced HRQoL and PACS+ were identified by multivariable Poisson regression.RESULTS: Persistent symptoms were experienced by 79% of hospitalized, and 59% of non-hospitalized patients at 6 months. Hospitalized patients had a higher prevalence of self-assessed reduced overall health (28 vs. 12%) and PACS+ (31 vs. 11%). PACS+ was associated with reduced exercise capacity but not with abnormal pulse/desaturation during 1MSTST. Hospitalization was the most important independent risk factor for developing persistent symptoms, reduced overall health and PACS+.CONCLUSION: Persistent symptoms and reduced HRQoL are common among COVID-19 survivors, but abnormal pulse and peripheral saturation during exercise could not distinguish patients with PACS+. Patients with severe infection requiring hospitalization were more likely to develop PACS+, hence these patients should be prioritized for clinical follow-up after COVID-19.
|
|
