| 1. |
- Ahlberg, Erik, et al.
(författare)
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"Vi klimatforskare stödjer Greta och skolungdomarna"
- 2019
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Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 15/3. Sedan industrialiseringens början har vi använt omkring fyra femtedelar av den mängd fossilt kol som får förbrännas för att vi ska klara Parisavtalet. Vi har bara en femtedel kvar och det är bråttom att kraftigt reducera utsläppen. Det har Greta Thunberg och de strejkande ungdomarna förstått. Därför stödjer vi deras krav, skriver 270 klimatforskare.
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| 2. |
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| 3. |
- Martinsson, Johan, et al.
(författare)
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Evaluation of delta C-13 in Carbonaceous Aerosol Source Apportionment at a Rural Measurement Site
- 2017
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 17:8, s. 2081-2094
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Tidskriftsartikel (refereegranskat)abstract
- The stable isotope of carbon, C-13, has been used in several studies for source characterization of carbonaceous aerosol since there are specific signatures for different sources. In rural areas, the influence of different sources is complex and the application of delta C-13 for source characterization of the total carbonaceous aerosol (TC) can therefore be difficult, especially the separation between biomass burning and biogenic sources. We measured delta C-13 from 25 filter samples collected during one year at a rural background site in southern Sweden. Throughout the year, the measured delta C-13 showed low variability (-26.73 to -25.64%). We found that the measured delta C-13 did not correlate with other commonly used source apportionment tracers (C-14, levoglucosan). delta C-13 values showed lower variability during the cold months compared to the summer, and this narrowing of the delta C-13 values together with elevated levoglucosan concentrations may indicate contribution from sources with lower delta C-13 variation, such as biomass or fossil fuel combustion. Comparison of two Monte Carlo based source apportionment models showed no significant difference in results when delta C-13 was incorporated in the model. The insignificant change of redistributed fraction of carbon between the sources was mainly a consequence of relatively narrow range of delta C-13 values and was complicated by an unaccounted kinetic isotopic effect and overlapping delta C-13 end-member values for biomass burning and biogenic sources.
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| 4. |
- Török, Sandra, et al.
(författare)
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Investigation of the absorption Ångström exponent and its relation to physicochemical properties for mini-CAST soot
- 2018
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Ingår i: Aerosol Science and Technology. - : Informa UK Limited. - 0278-6826 .- 1521-7388. ; 52:7, s. 757-767
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a mini-CAST soot generator was used to produce soot with different optical and physicochemical characteristics. Absorption Ångström exponents (AAE) expressing the absorption wavelength dependence were assessed by multiwavelength in-situ and filter-based (aethalometer) laser extinction. The two optical techniques showed good agreement. For the chosen mini-CAST operating conditions, AAEs between 1 and 3.5 were found. Soot with high mass-fractions of organic carbon (OC) and pyrolytic carbon (PC) determined with thermal optical analysis were associated with AAEs significantly higher than 1. Heating to 250 and 500°C removed the majority of polycyclic aromatic hydrocarbons. However, the thermal-optical analysis revealed that OC and PC were abundant in the soot with AAE > 2 also after heating the aerosol. Analysis of mass absorption cross section ratios for elemental carbon and OC indicated that elevated AAEs also after heating to 500°C could be related to persistent OC and PC components and/or the refractory soot. By comparing the mini-CAST soot optical properties with soot properties derived from in-situ extinction measurements in a premixed flame, mini-CAST soot with a higher AAE could be identified as less mature soot.
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| 5. |
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| 6. |
- Andersson, Sandra, et al.
(författare)
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Composition and evolution of volcanic aerosol from eruptions of Kasatochi, Sarychev and Eyjafjallajokull in 2008-2010 based on CARIBIC observations
- 2013
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7324. ; 13:4, s. 1781-1796
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Tidskriftsartikel (refereegranskat)abstract
- Large volcanic eruptions impact significantly on climate and lead to ozone depletion due to injection of particles and gases into the stratosphere where their residence times are long. In this the composition of volcanic aerosol is an important but inadequately studied factor. Samples of volcanically influenced aerosol were collected following the Kasatochi (Alaska), Sarychev (Russia) and also during the Eyjafjallajokull (Iceland) eruptions in the period 2008-2010. Sampling was conducted by the CARIBIC platform during regular flights at an altitude of 10-12 km as well as during dedicated flights through the volcanic clouds from the eruption of Eyjafjallajokull in spring 2010. Elemental concentrations of the collected aerosol were obtained by accelerator-based analysis. Aerosol from the Eyjafjallajokull volcanic clouds was identified by high concentrations of sulphur and elements pointing to crustal origin, and confirmed by trajectory analysis. Signatures of volcanic influence were also used to detect volcanic aerosol in stratospheric samples collected following the Sarychev and Kasatochi eruptions. In total it was possible to identify 17 relevant samples collected between 1 and more than 100 days following the eruptions studied. The volcanically influenced aerosol mainly consisted of ash, sulphate and included a carbonaceous component. Samples collected in the volcanic cloud from Eyjafjallajokull were dominated by the ash and sulphate component (similar to 45% each) while samples collected in the tropopause region and LMS mainly consisted of sulphate (50-77%) and carbon (21-43%). These fractions were increasing/decreasing with the age of the aerosol. Because of the long observation period, it was possible to analyze the evolution of the relationship between the ash and sulphate components of the volcanic aerosol. From this analysis the residence time (1/e) of sulphur dioxide in the studied volcanic cloud was estimated to be 45 +/- 22 days.
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| 7. |
- Andersson, Sofia, 1972-, et al.
(författare)
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End-of-life discussions in residential care homes improves symptom control : a national register study
- 2021
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Ingår i: BMJ Supportive & Palliative Care. - : BMJ Publishing Group Ltd. - 2045-435X .- 2045-4368.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In Europe, residential care homes (RCHs) rather than hospitals are the most common care facilities for the older adult and the place where most deaths occur in this age group. There is a lack of knowledge regarding end-of-life (EOL) discussions and how they correlate with symptoms and symptom relief.OBJECTIVE: The aim was to examine the correlation between EOL discussions and symptom occurrence, symptom relief and prescriptions or PRN drugs against symptoms for care home residents.METHODS: All expected deaths at RCHs from 1 October 2015 to 31 December 2016 and registered in the Swedish Register of Palliative Care were included. Univariate and multivariate logistic regression were used to compare the RCH residents, or their family members, who had received documented EOL discussions with a physician (the EOL discussion group) and the non-EOL discussion group.RESULTS: The EOL discussion group (n=17 071) had a higher prevalence of pain, nausea, anxiety, death rattles and shortness of breath reported, compared with the non-EOL discussion group (n=4164). Those with symptoms were more often completely relieved and had more often been prescribed PRN drugs against that symptom in the EOL discussion group. All differences remained significant when adjusting for age, time living in unit and cause of death.CONCLUSION: The results indicate that EOL discussions are correlated with higher prevalence of symptoms, but also with better symptom relief and prescription of symptom drugs PRN when symptomatic. A possible explanation for this is that the EOL discussion can work as an opportunity to discuss symptoms and treatment for symptom relief.
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| 8. |
- Andersson, Sandra, et al.
(författare)
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Significant radiative impact of volcanic aerosol in the lowermost stratosphere.
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Despite their potential to slow global warming, until recently, the radiative forcing associated with volcanic aerosols in the lowermost stratosphere (LMS) had not been considered. Here we study volcanic aerosol changes in the stratosphere using lidar measurements from the NASA CALIPSO satellite and aircraft measurements from the IAGOS-CARIBIC observatory. Between 2008 and 2012 volcanism frequently affected the Northern Hemisphere stratosphere aerosol loadings, whereas the Southern Hemisphere generally had loadings close to background conditions. We show that half of the global stratospheric aerosol optical depth following the Kasatochi, Sarychev and Nabro eruptions is attributable to LMS aerosol. On average, 30% of the global stratospheric aerosol optical depth originated in the LMS during the period 2008-2011. On the basis of the two independent, high-resolution measurement methods, we show that the LMS makes an important contribution to the overall volcanic forcing.
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| 9. |
- Azeem, Hafiz Abdul, et al.
(författare)
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Towards the isolation and estimation of elemental carbon in atmospheric aerosols using supercritical fluid extraction and thermo-optical analysis
- 2017
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 409:17, s. 4293-4300
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Tidskriftsartikel (refereegranskat)abstract
- Air-starved combustion of biomass and fossil fuels releases aerosols, including airborne carbonaceous particles, causing negative climatic and health effects. Radiocarbon analysis of the elemental carbon (EC) fraction can help apportion sources of its emission, which is greatly constrained by the challenges in isolation of EC from organic compounds in atmospheric aerosols. The isolation of EC using thermo-optical analysis is however biased by the presence of interfering compounds that undergo pyrolysis during the analysis. EC is considered insoluble in all acidic, basic, and organic solvents. Based on the property of insolubility, a sample preparation method using supercritical CO2 and methanol as co-solvent was developed to remove interfering organic compounds. The efficiency of the method was studied by varying the density of supercritical carbon dioxide by means of temperature and pressure and by varying the methanol content. Supercritical CO2 with 10% methanol by volume at a temperature of 60 °C, a pressure of 350 bar and 20 min static mode extraction were found to be the most suitable conditions for the removal of 59 ± 3% organic carbon, including compounds responsible for pyrolysis with 78 ± 16% EC recovery. The results indicate that the method has potential for the estimation and isolation of EC from OC for subsequent analysis methods and source apportionment studies.
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| 10. |
- Chen, Hao Yu, et al.
(författare)
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Association of FADS1/2 Locus Variants and Polyunsaturated Fatty Acids With Aortic Stenosis
- 2020
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Ingår i: JAMA cardiology. - : American Medical Association (AMA). - 2380-6583 .- 2380-6591. ; 5:6, s. 694-702
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Aortic stenosis (AS) has no approved medical treatment. Identifying etiological pathways for AS could identify pharmacological targets.Objective: To identify novel genetic loci and pathways associated with AS.Design, Setting, and Participants: This genome-wide association study used a case-control design to evaluate 44 703 participants (3469 cases of AS) of self-reported European ancestry from the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort (from January 1, 1996, to December 31, 2015). Replication was performed in 7 other cohorts totaling 256 926 participants (5926 cases of AS), with additional analyses performed in 6942 participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Follow-up biomarker analyses with aortic valve calcium (AVC) were also performed. Data were analyzed from May 1, 2017, to December 5, 2019.Exposures: Genetic variants (615 643 variants) and polyunsaturated fatty acids (ω-6 and ω-3) measured in blood samples.Main Outcomes and Measures: Aortic stenosis and aortic valve replacement defined by electronic health records, surgical records, or echocardiography and the presence of AVC measured by computed tomography.Results: The mean (SD) age of the 44 703 GERA participants was 69.7 (8.4) years, and 22 019 (49.3%) were men. The rs174547 variant at the FADS1/2 locus was associated with AS (odds ratio [OR] per C allele, 0.88; 95% CI, 0.83-0.93; P = 3.0 × 10-6), with genome-wide significance after meta-analysis with 7 replication cohorts totaling 312 118 individuals (9395 cases of AS) (OR, 0.91; 95% CI, 0.88-0.94; P = 2.5 × 10-8). A consistent association with AVC was also observed (OR, 0.91; 95% CI, 0.83-0.99; P = .03). A higher ratio of arachidonic acid to linoleic acid was associated with AVC (OR per SD of the natural logarithm, 1.19; 95% CI, 1.09-1.30; P = 6.6 × 10-5). In mendelian randomization, increased FADS1 liver expression and arachidonic acid were associated with AS (OR per unit of normalized expression, 1.31 [95% CI, 1.17-1.48; P = 7.4 × 10-6]; OR per 5-percentage point increase in arachidonic acid for AVC, 1.23 [95% CI, 1.01-1.49; P = .04]; OR per 5-percentage point increase in arachidonic acid for AS, 1.08 [95% CI, 1.04-1.13; P = 4.1 × 10-4]).Conclusions and Relevance: Variation at the FADS1/2 locus was associated with AS and AVC. Findings from biomarker measurements and mendelian randomization appear to link ω-6 fatty acid biosynthesis to AS, which may represent a therapeutic target.
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