| 26. |
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| 27. |
- Hedling, Erik, et al.
(författare)
-
Kollektivets kollaps: om dygden i svensk 90-talsfilm
- 2002
-
Ingår i: I ordets smedja. Festskrift till Per Rydén. - 91 7203 494 7
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This article deals with concepts of virtue in Swedish blockbusters of the late 1990s, arguing that the general theme seems to be the collapse of traditional Swedish welfare collectivity.
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| 28. |
- Heverin, Maura, et al.
(författare)
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On the regulatory importance of 27-hydroxycholesterol in mouse liver
- 2017
-
Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier. - 0960-0760 .- 1879-1220. ; 169, s. 10-21
-
Forskningsöversikt (refereegranskat)abstract
- 27-Hydroxycholesterol (27OH) is a strong suppressor of cholesterol synthesis and a weak activator of LXR in vitro. The regulatory importance of 27OH in vivo is controversial. Here we utilized male mice with increased levels of 27OH either due to increased production (CYP27A1 transgenic mice) or reduced metabolism (Cyp7b1-/- mice). We also used mice lacking 27OH due to a knockout of Cyp27a1. The latter mice were treated with cholic acid to compensate for reduced bile acid synthesis. The effects of the different levels of 27OH on Srebp- and other LXR-regulated genes in the liver were investigated. In the liver of CYP27tg mice we found a modest increase of the mRNA levels corresponding to the LXR target genes Cyp7b1 and Abca1. A number of other LXR-regulated genes were not affected. The effect on Abca1 mRNA was not seen in the liver of Cyp7b1-/- mice. There were little or no effects on cholesterol synthesis. In the liver of the Cyp27-/- mice treated with 0.025% cholic acid there was no significant effect of the knockout on the LXR target genes. In a previous work triple-knockout mice deficient in the biosynthesis of 24S-hydroxycholesterol, 25-hydroxycholesterol and 27OH were shown to have impaired response to dietary cholesterol, suggesting side-chain oxidized oxysterols to be mediators in cholesterol-induced effects on LXR target genes at a transcriptional level (Chen W. et al., Cell Metab. 5 (2007) 73-79). The hydroxylated oxysterol responsible for the effect was not defined. We show here that treatment of wildtype mice with dietary cholesterol under the same conditions as in the above study induced the LXR target genes Lpl, Abcg8 and Srebp1c in wild type mice but failed to activate the same genes in mice lacking 27-hydroxycholesterol due to a knockout of Cyp27. We failed to demonstrate the above effects at the protein level (Abcg8) or at the activity level (Lpl). The results suggest that 27OH is not an important regulator of Srebp- or LXR regulated genes under basal conditions in mouse liver. On the other hand 27OH appears to mediate cholesterol-induced effects on some LXR target genes at a transcriptional level under some in vivo conditions.
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| 29. |
- Holmberg, Martin, et al.
(författare)
-
Bacteria classification based on feature extraction from sensor data
- 1998
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Ingår i: Biotechnology Techniques. - : Kluwer Academic Publishers. - 0951-208X .- 1573-6784. ; 12:4, s. 319-324
-
Tidskriftsartikel (refereegranskat)abstract
- Data evaluation and classification have been made on measurements by an electronic nose on the headspace of samples of different types of bacteria growing on petri dishes. The chosen groups were: Escherichia coli, Enterococcus sp., Proteus mirabilis, Pseudomonas aeruginosa, and Staphylococcus saprophytica. An approximation of the response curve by time was made and the parameters in the curve fit were taken as important features of the data set. A classification tree was used to extract the most important features. These features were then used in an artificial neural network for classification. Using the ‘leave-one-out’ method for validating the model, a classification rate of 76% was obtained
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| 30. |
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| 31. |
- Jönsen, Andreas, et al.
(författare)
-
Direct and indirect costs for systemic lupus erythematosus in Sweden. A nationwide health economic study based on five defined cohorts
- 2016
-
Ingår i: Seminars in Arthritis & Rheumatism. - : Elsevier BV. - 0049-0172 .- 1532-866X. ; 45:6, s. 684-690
-
Forskningsöversikt (refereegranskat)abstract
- Objectives: The main objectives of this study were to calculate total costs of illness and cost -driving disease features among patients with systemic lupus erythematosus (SLE) in Sweden. Methods: Five cohorts of well-defined SLE patients, located in different parts of the country were merged. Incident and prevalent cases from 2003 through 2010 were included. The American College of Rheumatology (ACR) classification criteria was used. From the local cohorts, data on demographics, disease activity (SLEDAI 2K), and organ damage (SDI) were collected. Costs for inpatient care, specialist outpatient care and drugs were retrieved from national registries at the National Board of Health and Welfare. Indirect costs were calculated based on sickness leave and disability pensions from the Swedish Social Insurance Agency. Results: In total, 1029 SLE patients, 88% females, were included, and approximately 75% were below 65 years at the end of follow-up, and thus in working age. The mean number of annual specialist physician visits varied from six to seven; mean annual inpatient days were 3.1-3.6, and mean annual sick leave was 123-148 days, all per patient. The total annual cost was 208,555 SEK ($33,369 = 22,941(sic)), of which direct cost was 63,672kr ($10,188 = 7004(sic)) and the indirect cost was 144,883 SEK ($23,181 = 15,937(sic)), all per patient. The costs for patients with short disease duration were higher. Higher disease activity as measured by a SLEDAI 2K score > 3 was associated with approximately 50% increase in both indirect and direct costs. Damage in the neuropsychiatric and musculoskeletal domains were also linked to higher direct and indirect costs, while organ damage in the renal and ocular systems increased direct costs. Conclusion: Based on this study and an estimate of slightly more than 6000 SLE patients in Sweden, the total annual cost for SLE in the country is estimated at $188 million (= 129.5 million (sic)). Both direct (30%) and indirect costs (70%) are substantial. Medication accounts for less than 10% of the total cost. The tax paid national systems for health care and social security in Sweden ensure equal access to health care, sick leave reimbursements, and disability pensions nationwide. Our extrapolated annual costs for SLE in Sweden are therefore the best supported estimations thus far, and they clearly underline the importance of improved management, especially to reduce the indirect costs. (C) 2016 Elsevier Inc. All rights reserved.
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| 32. |
- Kabo, Jens, 1979, et al.
(författare)
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Naturvetenskapligt och tekniskt lärande: Samordning av ämnesdidaktik för tre ämnen
- 2014
-
Ingår i: Presenterat vid Nationell ämnesdidaktisk konferens NÄD2014. 9-11 april 2014. Göteborgs universitet, Göteborg..
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Chalmers har sedan 2011 rätt att utbilda ämneslärare för gymnasiet för undervisning i matematik och antingen fysik, kemi eller teknik. De ingenjörsstudenter som vill bli lärare väljer mastersprogrammet, Lärande och ledarskap, som löper över två år och består av tolv kurser samt ett avslutande examensarbete. Två av dessa kurser, Naturvetenskapligt och tekniskt lärande 1 & 2 (NTL1 & NTL2), behandlar ämnesdidaktik för fysik, kemi och teknik. NTL1 har ett mer praktiskt fokus (t.ex. planera och genomföra undervisning i sitt ämne) medan NTL2 har ett mer teoretiskt fokus (t.ex. modernare perspektiv på lärande, såsom variationsteori, i relation till det egna ämnet). En stor utmaning med dessa två kurser är att behandla ämnesdidaktik för tre ämnen inom en och samma kurs. I NTL1 har vi mött denna utmaning genom att strukturera kursen kring tre huvudkomponenter: *seminarier i helklass med fokus på sådant som är relevant för undervisning i alla tre ämnena som t.ex. ""backwards design"" och hållbar utveckling; *uppgifter där studenterna individuellt eller i grupp fokuserar på olika aspekter av undervisning och lärande i deras eget ämne; och *regelbundna mentorstillfällen med yrkesverksamma gymnasielärare i studentens eget ämne. NTL2 bygger på liknande principer och kommer framöver ha fördelen av att ligga parallellt med skolförlagd VFU. I detta bidrag redogör vi för hur vi arbetar med både praktiska och teoretiska dimensioner av ämnesdidaktik för fysik, kemi och teknik inom ramen för dessa två kurser samt några av de utmaningar och möjligheter vi har stött på i samband med detta arbete.
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| 33. |
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| 34. |
- Ning, Rui, et al.
(författare)
-
Assessing progression limits in different grades of keratoconus from a novel perspective : precision of measurements of the corneal epithelium
- 2024
-
Ingår i: Eye and Vision. - 2326-0254. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: To assess repeatability and reproducibility of corneal epithelium thickness (ET) measured by a spectral-domain optical coherence tomographer (SD-OCT)/Placido topographer (MS-39, CSO, Florence, Italy) in keratoconus (KC) population at different stages, as well as to determine the progression limits for evaluating KC progression. Methods: A total of 149 eyes were enrolled in this study, with 29 eyes in the forme fruste keratoconus (FFKC) group, 34 eyes in the mild KC group, 40 eyes in the moderate KC group, and 46 eyes in the severe KC group. Employing the within-subject standard deviation (Sw), test-retest variability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) to evaluate intraoperator repeatability and interoperator reproducibility. Results: The repeatability and reproducibility of MS-39 in patients with KC were acceptable, according to ICC values ranging from 0.732 to 0.954. However, patients with more severe KC and progressive peripheralization of the measurement points had higher TRTs but a thinning trend. The current study tended to set the cut-off values of mild KC, moderate KC, and severe KC to 4.9 µm, 5.2 µm, and 7.4 µm for thinnest epithelium thickness (TET). When differences between follow-ups are higher than those values, progression of the disease is possible. As for center epithelium thickness (CET), cut-off values for mild KC, moderate KC, and severe KC should be 2.8 µm, 4.4 µm, and 5.3 µm. This might be useful in the follow-up and diagnosis of keratoconus. Conclusions: This study demonstrated that the precision of MS-39 was reduced in measuring more severe KC patients and more peripheral corneal points. In determining disease progression, values should be differentiated between disease-related real changes and measurement inaccuracies. Due to the large difference in ET measured by MS-39 between various stages of disease progression, it is necessary to accurately grade KC patients to avoid errors in KC clinical decision-making.
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| 35. |
- Nygren, Ingemar Tobias, et al.
(författare)
-
Effects of tasting technique : sequential tasting vs. mixed tasting – on perception of dry white wine and blue mould cheese
- 2003
-
Ingår i: Food Service Technology. - : Wiley. - 1471-5732 .- 1471-5740. ; 3:2, s. 61-69
-
Tidskriftsartikel (refereegranskat)abstract
- The object of this study was to evaluate by means of descriptive sensory analysis the effect of mixed tasting on the perception of dry white wine and blue mould cheese, and to establish whether the tasting technique (sequential vs. mixed tasting) significantly affects this perception. A Swedish blue mould cheese, Bredsjö Blå, and a French blue mould cheese, Roquefort Société, and five commercial types of dry white wine were used. The same panel, selected and trained according to ISO standards, as in Nygren et al. (2002, 2003) carried out the descriptive analyses by means of a mixed tasting technique. The panel scored the same attributes for both cheese and wine as in Nygren et al. (2002, 2003). In general, the original wine attribute scores decreased more by means of mixed tasting technique than by means of sequential, while few changes of the original cheese attribute scores were observed. Overall, mixed tasting gave greater decreasing changes than sequential tasting.
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| 36. |
- Nygren, Ingemar Tobias, et al.
(författare)
-
Flavor changes produced by wine and food interactions : Chardonnay wine and Hollandaise sauce
- 2001
-
Ingår i: Journal of sensory studies. - 0887-8250 .- 1745-459X. ; 16:5, s. 461-470
-
Tidskriftsartikel (refereegranskat)abstract
- The change in flavor produced by food and wine interactions was explored using descriptive analysis of Hollandaise sauce prepared with two levels of butter and three wines: a Chardonnay which was unoaked, acidified with 1.5 g/L citric acid or aged in oak for one year. To measure the effect of the sauce on wine flavor, the intensity of citrus, buttery, and toasted flavor by mouth and of sourness and bitterness was rated in each wine before and after each sauce was tasted. In a second testing series, lemon, brothy and creamy-butter flavor by mouth and creamy mouthfeel were rated for each sauce before and after tasting each wine. The effect of Hollandaise sauce on wine flavor was greater than the effect of wines on sauce flavor, with the higher fat sauce having a slightly larger effect overall. Sour and bitter flavors of the wines decreased in intensity after Hollandaise sauce was tasted, while the buttery flavor by mouth increased. The toasted flavor decreased significantly in the oaked wine after the sauce had been tasted, while citrus flavor was decreased only for the unoaked wine.
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| 37. |
- Nygren, Ingemar Tobias, et al.
(författare)
-
Perceived flavour changes in blue mould cheese after tasting white wine
- 2003
-
Ingår i: Food Service Technology. - : Wiley. - 1471-5732 .- 1471-5740. ; 3:3-4, s. 143-150
-
Tidskriftsartikel (refereegranskat)abstract
- The object of this study was to evaluate by descriptive sensory analysis how prior tasting of dry white wine affects the sensory perception of blue mould cheese. Two blue mould cheeses, a Swedish one, Bredsjö Blå (Bredsjö Mjölkfår AB, Sweden), and a French one, Roquefort (Roquefort Société, France), were tasted in combination with five commercial dry white wines. Nine trained assessors assessed the cheeses and the wines in sequential order, with the cheese being assessed before and after tasting the wines. The main findings were that the most pronounced characteristics of the Bredsjö Blå, such as buttery and woolly flavours, and the saltiness and sour taste of the Roquefort, decreased after tasting dry white wine.
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| 38. |
- Nygren, Ingemar Tobias, et al.
(författare)
-
Perceived flavour changes in white wine after tasting blue mould cheese
- 2002
-
Ingår i: Food Service Technology. - : Wiley. - 1471-5732 .- 1471-5740. ; 2:4, s. 163-171
-
Tidskriftsartikel (refereegranskat)abstract
- The object of this study was to evaluate by descriptive sensory analysis how the sensory perception of dry white wines was affected by prior tasting of blue mould cheese. Trained assessors profiled five commercial white wines before and after tasting each of two blue mould cheeses. The study showed that descriptive sensory analysis could be used to quantify changes in the perception of white wines after the consumption of cheese. For all five wines the main findings were that most of the intensities of perceived flavours and acidity decreased after tasting blue mould cheese.
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| 39. |
- Nygren, Ingemar Tobias, 1968-
(författare)
-
Sensory evaluation and consumer preference of wine and food combinations : influences of tasting techniques
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The entire project consists of five studies. Descriptive sensory analyses were performed on combinations of five dry white wines and either Hollandaise sauce with two levels of fat or two blue mould cheeses. Assessments were carried out by a student panel and by a selected and trained panel. The effect of tasting technique on defined attributes was investigated: firstly by switching the order of serving wine and sauce or wine and cheese within the sequential tasting technique and secondly by mixing wine and cheese in the mouth, mixed tasting technique. Finally, consumers in Norway and Sweden, accustomed to drinking wine and eating blue mould cheese, carried out a preference test on wine and cheese combinations. The perception of the white wine characteristics generally decreased in intensity after the tasting of Hollandaise sauce. The buttery flavour of wine, however, increased after the tasting of Hollandaise sauce. Generally, the perception of dry white wine flavours (blackcurrant leaf, oak, mineral, spice) decreased after the tasting of both cheeses, whether the tasting was sequential or mixed. Few changes in the perception of the sauce attributes were observed after the tasting of white wine. However, lemon flavour of Hollandaise sauce decreased after the tasting of oaked wine. The perception of pronounced cheese flavours (butter, wool, basement-like) and tastes (sour and salty) decreased after the tasting of dry white wine for both sequential and mixed tasting whereas the other attributes remained unchanged. The perception of the wine attributes decreased more in the case of mixed tasting technique than in the case of sequential, while few changes in the perception of the cheese attributes were observed. Sweetness, however, increased in the Roquefort cheese mixed with certain wines. The consumers in both Norway and Sweden usually (80%) drank dry red wine with blue mould cheese. The Norwegian consumers preferred dry red wines to sweet red wines in combination with blue mould cheese. The wines rather than the cheeses separated the preferences regarding the combinations.
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| 40. |
- Nylander, Charlotte, 1979-, et al.
(författare)
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Self- and parent-reported executive problems in adolescents with type 1 diabetes are associated with poor metabolic control and low physical activity.
- 2018
-
Ingår i: Pediatric Diabetes. - : Hindawi Limited. - 1399-543X .- 1399-5448. ; 19:1, s. 98-105
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Management of diabetes is demanding and requires efficient cognitive skills, especially in the domain of executive functioning. However, the impact of impaired executive functions on diabetes control has been studied to a limited extent. The aim of the study is to investigate the association between executive problems and diabetes control in adolescents with type 1 diabetes.MATERIALS AND METHODS: Two hundred and forty-one of 477 (51%) of 12- to 18-year-old adolescents, with a diabetes duration of >2 years in Stockholm, Uppsala, and Jönköping participated. Parents and adolescents completed questionnaires, including Behavioral Rating Inventory of Executive Function (BRIEF), Attention-Deficit/Hyperactivity Disorder (ADHD)-Rating Scale (ADHD-RS) and demographic background factors. Diabetes-related data were collected from the Swedish Childhood Diabetes Registry, SWEDIABKIDS. Self-rated and parent-rated executive problems were analyzed with regard to gender, glycosylated hemoglobin (HbA1c), frequency of outpatient visits, and physical activity, using chi-square tests or Fisher's test, where P-values <.05 were considered significant. Furthermore, adjusted logistic regressions were performed with executive problems as independent variable.RESULTS: Executive problems, according to BRIEF and/or ADHD-RS were for both genders associated with mean HbA1c >70 mmol/mol (patient rating P = .000, parent rating P = .017), a large number of outpatient visits (parent rating P = .015), and low physical activity (patient rating P = .000, parent rating P = .025). Self-rated executive problems were more prevalent in girls (P = .032), while parents reported these problems to a larger extent in boys (P = .028).CONCLUSION: Executive problems are related to poor metabolic control in adolescents with type 1 diabetes. Patients with executive problems need to be recognized by the diabetes team and the diabetes care should be organized to provide adequate support for these patients.
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| 41. |
- Nyman-Carlsson, Erika, 1982-
(författare)
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Anorexia nervosa - The journey towards recovery : A randomized controlled treatment trial: assessment, prediction, treatment outcome and clinical change
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis was to study young adult women with anorexia nervosa (AN) participating in an randomized controlled trial in relation to assessment, treatment outcome, prediction, and clinical change. The results confirm the Eating Disorder Inventory-3 as a valid instrument for measuring eating disorder symptoms and general psychopathology. AN patients, however, rate themselves significantly lower than patients with other eating disorder diagnoses, and interoceptive deficits are the best predictive subscale for AN diagnosis. Patients significantly improved in terms of weight and eating disorder psychopathology, with no differences between individual CBT and family therapy (FT). Most patients did not fulfill the diagnostic criteria at post-assessment, at 76% and 86% at followup. Patients in FT were considered completers to a higher extent than patients receiving CBT, and 8% were prematurely discharged, in comparison to 30% for CBT. Bulimic symptoms and emotional dysregulation at baseline had a negative effect on diagnostic symptoms, and lower levels of interoceptive deficits predicted weight increase in the FT group. Lower levels of emotional dysregulation and higher levels of interoceptive deficits explained 37% of the variance in BMI changes in the CBT group. The classifications of CS/RCI were shown to be valid when compared to normal controls. Patients classified as clinically significantly improved constituted 35-47% of all patients, and only three patients fulfilled the proposed definition of recovery. The agreement of the diagnostic criteria was fair.The results suggest that individual CBT and FT are effective treatments for young adults. The ability to acknowledge, interpret, and handle emotions is an important aspect of treatment. Self-report measurements are useful for evaluating individual changes; however, diagnostic criteria do not accord with self-reported symptom changes and physical, behavioral, and psychological measurements are important for a complete estimation of recovery.
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| 42. |
- Nyman-Carlsson, Erika, 1982-, et al.
(författare)
-
Individual cognitive behavioral therapy and combined family/individual therapy for young adults with Anorexia nervosa : A randomized controlled trial
- 2020
-
Ingår i: Psychotherapy Research. - : Routledge. - 1050-3307 .- 1468-4381. ; 30:8, s. 1011-1025
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In this study, we evaluate the efficacy of outpatient individual cognitive behavioral therapy for young adults (CBT-YA) and combined family/individual therapy for young adults (FT-YA) for anorexia nervosa (AN).METHOD: Participants (aged 17-24 years) with AN in Sweden were recruited and assigned to 18 months of CBT-YA or FT-YA. Treatment efficacy was assessed primarily using BMI, presence of diagnosis, and degree of eating-related psychopathology at post-treatment and follow-up. Secondary outcomes included depression and general psychological psychopathology. The trial was registered at http://www.isrctn.com/, ISRCTN (25181390).RESULTS: Seventy-eight participants were randomized, and seventy-four of them received allocated treatment and provided complete data. Clinical outcomes from within groups resulted in significant improvements for both groups. BMI increased from baseline (CBT-YA 16.49; FT-YA 16.54) to post-treatment (CBT-YA 19.61; FT-YA 19.33) with high effect sizes. The rate of weight restoration was 64.9% in the CBT-YA group and 83.8% in the FT-YA group. The rate of recovery was 76% in both groups at post-treatment, and at follow-up, 89% and 81% had recovered in the CBT-YA and FT-YA groups respectively.CONCLUSIONS: Outpatient CBT-YA and FT-YA appear to be of benefit to young adults with AN in terms of weight restoration and reduced eating disorder and general psychopathology.
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| 43. |
- Nyman-Carlsson, Erika, 1982-, et al.
(författare)
-
Predictors of outcome among young adult patients with anorexia nervosa in a randomised controlled trial
- 2019
-
Ingår i: European eating disorders review. - : John Wiley & Sons. - 1072-4133 .- 1099-0968. ; 27:1, s. 76-85
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The prognosis in cases of anorexia nervosa (AN) is unsatisfactory, and it is therefore important to examine pretreatment predictors of outcome.METHODS: Female AN patients (N = 74) included in a randomised controlled trial receiving individual cognitive behavioural therapy (CBT) or family-based treatment (FBT) were included. Predictors of the outcome were explored using pretreatment eating disorder psychopathology.RESULTS: In the CBT group, lower levels of emotional dysregulation and greater deficits in identifying and coping with inner states were predictors of weight increase, explaining 37.7% of the variance. In the FBT group, lower interoceptive deficits predicted an increase in weight (explaining 17.7% of the variance), whereas bulimic behaviour (32.4%) and problems with emotional regulation (23.3%) were predictors of increased diagnostic symptoms.CONCLUSIONS: Bulimic symptoms and the ability to identify and cope with emotional states appear to be important aspects that should be addressed in the treatment of young adult patients with AN.
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| 44. |
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| 45. |
- Oscarsson, Ingemar, et al.
(författare)
-
Från statstidning till akademitidning (1734-1809)
- 2005
-
Ingår i: Världens äldsta. Post- och Inrikes Tidningar under 1600-, 1700-, 1800-, 1900- och 2000-talen. - 9173530778 ; , s. 131-236
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 46. |
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| 47. |
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| 48. |
- Oscarsson, Ingemar, et al.
(författare)
-
Svensk landsortspress 1732-1809
- 1998
-
Ingår i: Ständigt dessa landsortstidningar. - 1403-3585. ; 3, s. 13-43
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 49. |
- Sanchez-Garcia, Laura, et al.
(författare)
-
Evaluation of the influence of black carbon on the distribution of PAHs in sediments from along the entire Swedish continental shelf
- 2010
-
Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203 .- 1872-7581. ; 119:1-4, s. 44-51
-
Tidskriftsartikel (refereegranskat)abstract
- A growing literature is proposing that combusted-derived black carbon (BC) is dominating the sorption and, by inference, the environmental distribution and bioavailability of many hydrophobic pollutant classes. Yet, there is a paucity of studies evaluating simultaneously the distribution of both BC geosorbents and pollutant sorbates in the actual field. Here, 120 surface sediments collected by the Geological Survey of Sweden along the 2000 km continental shelf along the Swedish coast facilitated evaluation of the relative influences of BC and non-BC organic carbon (OC) on the spatial distribution of polycyclic aromatic hydrocarbons (PAHs). The sum of 15 out of the 16 EPA PAHs ranged from 0.12 to 9.6 μg/g dry weight (dw), with the highest levels being found in the southern half of the Swedish Shelf (SS) area and in the vicinity of larger cities (Stockholm, Göteborg, Malmö and Umeå). Source-diagnostic PAH ratios such as ANT/(PHE+ANT), FLT/(FLT+PYR), BaA/(BaA+BPE), IPY/(IPY+BPE), CombPAH/ΣPAH and LMW/HMW suggested that pyrogenic sources are dominating the load of PAHs in Swedish Baltic and North Sea sediments. The sediment TOC was 4.8-168 mg/gdw (median 43 mg/gdw), while a BC concentration of 0.6-18 mg/gdw (median 1.8 mg/gdw) yielded BC:TOC ratios spanning a wide range of 1.7-47 % (median 4.6 %). Empirical distribution function tests disqualified linear regression statistics. Instead, evaluation with the non-parametric Spearman function yielded higher correlation coefficient (rS) for total PAHs versus BC (0.54, p<0.01) than versus either TOC (0.28, p<0.01) or OC (TOC-BC; 0.26, p<0.01). The results from this field study, encompassing an order of magnitude more observations than any previous sediment study, is a broad field manifestation of the importance of BC in affecting the distribution of planar aromatic pollutants in aquatic environments.
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| 50. |
- Sánchez-García, Laura, et al.
(författare)
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The sequestration sink of soot black carbon in the Northern European Shelf sediments
- 2012
-
Ingår i: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 26
-
Tidskriftsartikel (refereegranskat)abstract
- To test the hypothesis that ocean margin sediments are a key final repository in the large-scale biogeospheric cycling of soot black carbon (soot-BC), an extensive survey was conducted along the ∼2,000 km stretch of the Swedish Continental Shelf (SCS). The soot-BC content in the 120 spatially distributed SCS sediments was 0.180.13 0.26% dw (median with interquartile ranges), corresponding to ∼5% of total organic carbon. Using side-scan sonar constraints to estimate the areal fraction of postglacial clay sediments that are accumulation bottoms (15% of SCS), the soot-BC inventory in the SCS mixed surface sediment was estimated at ∼4,000 Gg. Combining this with radiochronological constraints on sediment mass accumulation fluxes, the soot-BC sink on the SCS was ∼300 Gg/yr, which yielded an area-extrapolated estimate for the Northern European Shelf (NES) of ∼1,100 Gg/yr. This sediment soot-BC sink is ∼50 times larger than the river discharge fluxes of soot-BC to these coastal waters, however, of similar magnitude as estimates of atmospheric soot-BC emission from the upwind European continent. While large uncertainties remain regarding the large-scale to global BC cycle, this study combines with two previous investigations to suggest that continental shelf sediments are a major final repository of atmospheric soot-BC. Future progress on the soot-BC cycle and how it interacts with the full carbon cycle is likely to benefit from 14C determinations of the sedimentary soot-BC and similar extensive studies of coastal sediment in complementary regimes such as off heavily soot-BC-producing areas in S and E Asia and on the large pan-Arctic shelf. Copyright 2012 by the American Geophysical Union.
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