| 1. |
- Bergh, Caroline, et al.
(författare)
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Organophosphate and phthalate esters in indoor air : a comparison between multi-storey buildings with high and low prevalence of sick building symptoms
- 2011
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Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry (RSC). - 1464-0325 .- 1464-0333. ; 13:7, s. 2001-2009
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Tidskriftsartikel (refereegranskat)abstract
- An extensive study has been conducted of the prevalence of organophosphorous flame retardants/plasticizers and phthalate ester plasticizers in indoor air. The targeted substances were measured in 45 multi-storey apartment buildings in Stockholm, Sweden. The apartment buildings were classified as high or low risk with regard to the reporting of sick building symptoms (SBS) within the project Healthy Sustainable Houses in Stockholm (3H). Air samples were taken from two to four apartments per building (in total 169 apartments) to facilitate comparison within and between buildings. Association with building characteristics have been examined as well as association with specific sources by combining chemical analysis and exploratory uni- and multivariate data analysis. The study contributes to the overall perspective of levels of organophosphate and phthalate ester in indoor air enabling comparison with other studies. The results indicated little or no difference in the concentrations of the target substances between the two risk classifications of the buildings. The differences between the apartments sampled within (inter) buildings were greater than the differences between (intra) buildings. The concentrations measured in air ranged up to 1,200 ng/m3 for organophosphate esters and up to 11,000 ng/m3 for phthalate esters. Results in terms of sources were discerned e.g. PVC flooring is a major source of benzylbutyl phthalate in indoor air.
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| 2. |
- Hansson, Emma, et al.
(författare)
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Analysis of complications after repair of hypospadias
- 2007
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Ingår i: Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. - : Informa UK Limited. - 1651-2073 .- 0284-4311. ; 41:3, s. 120-124
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Tidskriftsartikel (refereegranskat)abstract
- We have reviewed 184 patients after repair of primary hypospadias. They were operated on and followed-up according to a standard protocol, and the senior author (HS) participated in all operations. The patients were reconstructed using a Byars two-stage procedure ( n = 102) or a Scuderi ( n = 29) or Mathieu ( n = 41) single-stage procedure. The rest ( n = 12) just had a removal of the chordee with realignment of the skin. Complications recorded were haematomas, postoperative infections, malfunction of catheter, urinary retention, fistulas, and strictures. Thirty-eight complications developed in 26 patients and the overall incidence of fistula was 22 in 18 patients (10%). Our findings suggest that the most decisive risk factor for complications is the severity of the primary malformation, because a severe malformation per se is difficult to treat as it requires a long reconstruction; in addition the curvature, shortage of tissue, and extensive surgery generally require a staged reconstruction in these cases. Other factors seem to be of much lesser importance.
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| 3. |
- Monie, Svante, 1972-
(författare)
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Balancing variable renewable electricity generation using combined heat and power plants, large-scale heat pumps, and thermal energy storages in Swedish district heating systems
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value the delivered services are likely required. The overall conclusions are: DHSs can offer power balancing, a high share of PV is essential to reduce fuel use, and finally, seasonal TESs are needed to cope with large amounts of surplus heat and/or replacement of peak load units.
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| 4. |
- Olofsson, K, et al.
(författare)
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Self-perception after hypospadias repair in young men's perspective
- 2003
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Ingår i: European Journal of Plastic Surgery. - : Springer Science and Business Media LLC. - 0930-343X .- 1435-0130. ; 26:6, s. 294-297
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-one males underwent an interview, clinical investigation, and measurement of urine flow and residual volume 15-25 years after surgery. Although surgical techniques have been improved during recent decades, the results of hypospadias repair made 20 years ago are nethertheless acceptable and most patients regard the outcome as satisfactory.
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| 5. |
- Otnes, Gaute, et al.
(författare)
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Understanding InP Nanowire Array Solar Cell Performance by Nanoprobe-Enabled Single Nanowire Measurements
- 2018
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 18:5, s. 3038-3046
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Tidskriftsartikel (refereegranskat)abstract
- III-V solar cells in the nanowire geometry might hold significant synthesis-cost and device-design advantages as compared to thin films and have shown impressive performance improvements in recent years. To continue this development there is a need for characterization techniques giving quick and reliable feedback for growth development. Further, characterization techniques which can improve understanding of the link between nanowire growth conditions, subsequent processing, and solar cell performance are desired. Here, we present the use of a nanoprobe system inside a scanning electron microscope to efficiently contact single nanowires and characterize them in terms of key parameters for solar cell performance. Specifically, we study single as-grown InP nanowires and use electron beam induced current characterization to understand the charge carrier collection properties, and dark current-voltage characteristics to understand the diode recombination characteristics. By correlating the single nanowire measurements to performance of fully processed nanowire array solar cells, we identify how the performance limiting parameters are related to growth and/or processing conditions. We use this understanding to achieve a more than 7-fold improvement in efficiency of our InP nanowire solar cells, grown from a different seed particle pattern than previously reported from our group. The best cell shows a certified efficiency of 15.0%; the highest reported value for a bottom-up synthesized InP nanowire solar cell. We believe the presented approach have significant potential to speed-up the development of nanowire solar cells, as well as other nanowire-based electronic/optoelectronic devices.
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| 6. |
- Savolainen, Johannes, et al.
(författare)
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Structured intervention plan including component-resolved diagnostics helps reducing the burden of food allergy among school-aged children
- 2019
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Ingår i: Pediatric Allergy and Immunology. - : WILEY. - 0905-6157 .- 1399-3038. ; 30:1, s. 99-106
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Tidskriftsartikel (refereegranskat)abstract
- Background Food allergies can substantially burden patients and families by negatively affecting finances, social relationships, and personal perceptions of health. This study was performed under the Finnish Allergy Programme aimed at reducing avoidance diets to foods in schoolchildren by 50%. The main goal of this study was to investigate how many children could be freed from diet restrictions in a Finnish school district through a diagnostic algorithm including component-resolved diagnostics and food challenge. The secondary aim was to provide a crude estimate of the burden of the elimination food diets in the region, and the savings associated with the proposed intervention. Methods A total of 205 children on a food avoidance diet according to the school register because of food allergy were invited into the study. One hundred and fifty-seven children were interviewed, tested for IgE to extracts and allergen components and food challenged in respective order. Results After two years, 12 children still had an avoidance diet and three of them were treated successfully with sOTI; the rest suspended their avoidance diet (n = 134) or dropped out of the study (n = 11). The cost of the elimination diets was estimated in 172 700euro per year at start and 13 200euro per year at the end of the study; total savings were 128 400euro yearly. Conclusions The results demonstrate a 65% reduction of avoidance diets to foods in school-aged children, exceeding the 50% aim of the Finnish Allergy Programme. Therefore, it is possible to actively reduce the number of food allergy diagnoses that remain unmonitored in the society through a tailored diagnostic work-up.
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| 7. |
- Yamamoto-Hanada, Kiwako, et al.
(författare)
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IgE responses to multiple allergen components among school-aged children in a general population birth cohort in Tokyo
- 2020
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Ingår i: World Allergy Organization Journal. - : Elsevier. - 1939-4551. ; 13:2
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Response patterns to allergen components among Japanese children have not been studied extensively. Objective: Our aim was to examine the differences in sensitization patterns at ages 5 years and 9 years to identify longitudinal changes in the degree and patterns of sensitization in a birth cohort of Japanese children. Methods: Our study enrolled 984 children at aged 5 years between 2008 and 2010, and 729 children aged 9 years between 2012 and 2014. Allergic diseases were assessed using the ISAAC and UK Working Party's Diagnostic Criteria. Serum-specific IgE titers to allergen components were measured by multiplex array ImmunoCAP ISAC when the children were aged 5 and 9 years. Principal component analysis (PCA) was performed to characterize IgE sensitization to allergen components. Results: The prevalence of allergic rhinitis increased considerably over time (10.6%-31.2%). Furthermore, the sensitization prevalence to allergen-specific IgE (sIgE) also increased from 57.8% at age 5 years to 74.8% at age 9 years. IgE sensitization prevalence to Der f 1 (mites) was 42.1% at age 5 years and 54.3% at age 9 years. Furthermore, children were highly sensitized to Cry j 1 (Japanese cedar) (32.8% at age 5 years and 57.8% at age 9 years). Principle component analysis showed that sensitization to PR-10 cross-reactive components was independent of sensitization to mite and that no children acquired sensitization to pollen before acquiring sensitization to mite. Conclusions: The prevalence of allergic rhinitis and related allergen components increased from age 5 years to age 9 years in Japanese children.
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| 8. |
- Zamani, Leila, et al.
(författare)
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High cell density perfusion culture has a maintained exoproteome and metabolome
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Chinese hamster ovary (CHO) cells are the workhorse to produce recombinant proteins in the biopharmaceutical industry using mammalian cells and are commonly cultured in either fed-batch or perfusion mode. The optimization of the complex biological systems used in such processes is extremely challenging. Multi-omics approaches can reveal otherwise unknown characteristics of these systems and identify culture parameters that can be manipulated to optimize the cultivation process. Here we have ap- plied both metabolomic and proteomic profiling to a monoclonal antibody (mAb) production operated in perfusion mode to explore how cell biology and reactor environment change as the cell density reaches ≥ 200 x 106 cells/mL. The extracellular metabolic composition obtained in perfusion mode was also com- pared to fed-batch, which showed a more stable profile for perfusion despite a far larger range of viable cell densities. The proteomics data showed an increase of structural proteins as the cell density increased, and both the proteomic and metabolic results showed signs of oxidative stress and changes in glutathione metabolism at very high cell densities. The methodology presented herein could be a powerful tool for optimizing cultivation processes and recombinant protein production.
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| 9. |
- Zamani, Leila, et al.
(författare)
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High Cell Density Perfusion Culture has a Maintained Exoproteome and Metabolome
- 2018
-
Ingår i: Biotechnology Journal. - : Wiley. - 1860-6768 .- 1860-7314. ; 13:10
-
Tidskriftsartikel (refereegranskat)abstract
- The optimization of bioprocesses for biopharmaceutical manufacturing by Chinese hamster ovary (CHO) cells can be a challenging endeavor and, today, heavily relies on empirical methods treating the bioreactor process and the cells as black boxes. Multi-omics approaches have the potential to reveal otherwise unknown characteristics of these systems and identify culture parameters to more rationally optimize the cultivation process. Here, the authors have applied both metabolomic and proteomic profiling to a perfusion process, using CHO cells for antibody production, to explore how cell biology and reactor environment change as the cell density reaches 200x10(6)cellsmL(-1). The extracellular metabolic composition obtained in perfusion mode shows a markedly more stable profile in comparison to fed-batch, despite a far larger range of viable cell densities in perfusion. This stable profile is confirmed in the extracellular proteosome. Furthermore, the proteomics data shows an increase of structural proteins as cell density increases, which could be due to a higher shear stress and explain the decrease in cell diameter at very high cell densities. Both proteomic and metabolic results shows signs of oxidative stress and changes in glutathione metabolism at very high cell densities. The authors suggest the methodology presented herein to be a powerful tool for optimizing processes of recombinant protein production.
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| 10. |
- Åberg, Maria A I, 1972, et al.
(författare)
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Cardiovascular fitness is associated with cognition in young adulthood.
- 2009
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490.
-
Tidskriftsartikel (refereegranskat)abstract
- During early adulthood, a phase in which the central nervous system displays considerable plasticity and in which important cognitive traits are shaped, the effects of exercise on cognition remain poorly understood. We performed a cohort study of all Swedish men born in 1950 through 1976 who were enlisted for military service at age 18 (N = 1,221,727). Of these, 268,496 were full-sibling pairs, 3,147 twin pairs, and 1,432 monozygotic twin pairs. Physical fitness and intelligence performance data were collected during conscription examinations and linked with other national databases for information on school achievement, socioeconomic status, and sibship. Relationships between cardiovascular fitness and intelligence at age 18 were evaluated by linear models in the total cohort and in subgroups of full-sibling pairs and twin pairs. Cardiovascular fitness, as measured by ergometer cycling, positively associated with intelligence after adjusting for relevant confounders (regression coefficient b = 0.172; 95% CI, 0.168-0.176). Similar results were obtained within monozygotic twin pairs. In contrast, muscle strength was not associated with cognitive performance. Cross-twin cross-trait analyses showed that the associations were primarily explained by individual specific, non-shared environmental influences (>/=80%), whereas heritability explained <15% of covariation. Cardiovascular fitness changes between age 15 and 18 y predicted cognitive performance at 18 y. Cox proportional-hazards models showed that cardiovascular fitness at age 18 y predicted educational achievements later in life. These data substantiate that physical exercise could be an important instrument for public health initiatives to optimize educational achievements, cognitive performance, as well as disease prevention at the society level.
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| 11. |
- Ahmed, Trifa M., et al.
(författare)
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Determination of oxygenated and native polycyclic aromatic hydrocarbons in urban dust and diesel particulate matter standard reference materials using pressurized liquid extraction and LC-GC/MS
- 2015
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 407:2, s. 427-438
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to develop a novel analytical chemistry method, comprised of a coupled high-performance liquid chromatography-gas chromatography/mass spectrometry system (LC-GC/MS) with low detection limits and high selectivity, for the identification and determination of oxygenated polycyclic aromatic hydrocarbons (OPAHs) and polycyclic aromatic hydrocarbons (PAHs) in urban air and diesel particulate matter. The linear range of the four OPAHs, which include 9,10-anthraquinone, 4H-cyclopenta[def]phenanthrene-4-one, benzanthrone, and 7,12-benz[a]anthraquinone, was 0.7 pg-43.3 ng with limits of detection (LODs) and limits of quantification (LOQs) on the order of 0.2-0.8 and 0.7-1.3 pg, respectively. The LODs in this study are generally lower than values reported in the literature, which can be explained by using large-volume injection. The recoveries of the OPAHs spiked onto glass fiber filters using two different pressurized liquid extraction (PLE) methods were in the ranges of 84-107 and 67-110 %, respectively. The analytical protocols were validated using the following National Institute of Standards and Technology standard reference materials: SRM 1649a (Urban Dust), SRM 1650b (Diesel Particulate Matter), and SRM 2975 (Diesel Particulate Matter, Industrial Forklift). The measured mass fractions of the OPAHs in the standard reference materials (SRMs) in this present study are higher than the values from the literature, except for benzanthrone in SRM 1649a (Urban Dust). In addition to the OPAHs, 44 PAHs could be detected and quantified from the same particulate extract used in this protocol. Using data from the literature and applying a two-sided t test at the 5 % level using Bonferroni correction, significant differences were found between the tested PLE methods for individual PAHs. However, the measured mass fractions of the PAHs were comparable, similar to, or higher than those previously reported in the literature.
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| 12. |
- Alm, Erik, 1980-, et al.
(författare)
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A solution to the 1D NMR alignment problem using an extended generalized fuzzy Hough transform and mode support
- 2009
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 395:1, s. 213-223
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Tidskriftsartikel (refereegranskat)abstract
- This paper approaches the problem of intersample peak correspondence in the context of later applying statistical data analysis techniques to 1D 1H-nuclear magnetic resonance (NMR) data. Any data analysis methodology will fail to produce meaningful results if the analyzed data table is not synchronized, i.e., each analyzed variable frequency (Hz) does not originate from the same chemical source throughout the entire dataset. This is typically the case when dealing with NMR data from biological samples. In this paper, we present a new state of the art for solving this problem using the generalized fuzzy Hough transform (GFHT). This paper describes significant improvements since the method was introduced for NMR datasets of plasma in Csenki et al. (Anal Bioanal Chem 389:875-885, 15) and is now capable of synchronizing peaks from more complex datasets such as urine as well as plasma data. We present a novel way of globally modeling peak shifts using principal component analysis, a new algorithm for calculating the transform and an effective peak detection algorithm. The algorithm is applied to two real metabonomic 1H-NMR datasets and the properties of the method are compared to bucketing. We implicitly prove that GFHT establishes the objectively true correspondence. Desirable features of the GFHT are: (1) intersample peak correspondence even if peaks change order on the frequency axis and (2) the method is symmetric with respect to the samples.
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| 13. |
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| 14. |
- Alm, Erik, 1980-, et al.
(författare)
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Automated annotation and quantification of metabolites in (1)H NMR data of biological origin
- 2012
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 403:2, s. 443-455
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Tidskriftsartikel (refereegranskat)abstract
- In 1H NMR metabolomic datasets, there are often over a thousand peaks per spectrum, many of which change position drastically between samples. Automatic alignment, annotation, and quantification of all the metabolites of interest in such datasets have not been feasible. In this work we propose a fully automated annotation and quantification procedure which requires annotation of metabolites only in a single spectrum. The reference database built from that single spectrum can be used for any number of 1H NMR datasets with a similar matrix. The procedure is based on the generalized fuzzy Hough transform (GFHT) for alignment and on Principal-components analysis (PCA) for peak selection and quantification. We show that we can establish quantities of 21 metabolites in several 1H NMR datasets and that the procedure is extendable to include any number of metabolites that can be identified in a single spectrum. The procedure speeds up the quantification of previously known metabolites and also returns a table containing the intensities and locations of all the peaks that were found and aligned but not assigned to a known metabolite. This enables both biopattern analysis of known metabolites and data mining for new potential biomarkers among the unknowns.
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| 15. |
- Alm, Erik, 1980-
(författare)
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Solving the correspondence problem in analytical chemistry : Automated methods for alignment and quantification of multiple signals
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When applying statistical data analysis techniques to analytical chemical data, all variables must have correspondence over the samples dimension in order for the analysis to generate meaningful results. Peak shifts in NMR and chromatography destroys that correspondence and creates data matrices that have to be aligned before analysis. In this thesis, new methods are introduced that allow for automated transformation from unaligned raw data to aligned data matrices where each column corresponds to a unique signal. These methods are based around linear multivariate models for the peak shifts and Hough transform for establishing the parameters of these linear models. Methods for quantification under difficult conditions, such as crowded spectral regions, noisy data and unknown peak identities are also introduced. These methods include automated peak selection and a robust method for background subtraction. This thesis focuses on the processing of the data; the experimental work is secondary and is not discussed in great detail. All the developed methods are put together in a full procedure that takes us from raw data to a table of concentrations in a matter of minutes. The procedure is applied to 1H-NMR data from biological samples, which is one of the toughest alignment tasks available in the field of analytical chemistry. It is shown that the procedure performs consistently on the same level as much more labor intensive manual techniques such as Chenomx NMRSuite spectral profiling. Several kinds of datasets are evaluated using the procedure. Most of the data is from the field of Metabolomics, where the goal is to establish concentrations of as many small molecules as possible in biological samples.
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| 16. |
- Alm, Erik, 1980-, et al.
(författare)
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Time-resolved biomarker discovery inH-NMR data using generalized fuzzy Hough transform alignment and parallel factor analysis
- 2010
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 396:5, s. 1681-1689
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Tidskriftsartikel (refereegranskat)abstract
- This work addresses the subject of time-series analysis of comprehensive 1H-NMR data of biological origin. One of the problems with toxicological and efficacy studies is the confounding of correlation between the administered drug, its metabolites and the systemic changes in molecular dynamics, i.e., the flux of drug-related molecules correlates with the molecules of system regulation. This correlation poses a problem for biomarker mining since this confounding must be untangled in order to separate true biomarker molecules from dose-related molecules. One way of achieving this goal is to perform pharmacokinetic analysis. The difference in pharmacokinetic time profiles of different molecules can aid in the elucidation of the origin of the dynamics, this can even be achieved regardless of whether the identity of the molecule is known or not. This mode of analysis is the basis for metabonomic studies of toxicology and efficacy. One major problem concerning the analysis of 1H-NMR data generated from metabonomic studies is that of the peak positional variation and of peak overlap. These phenomena induce variance in the data, obscuring the true information content and are hence unwanted but hard to avoid. Here, we show that by using the generalized fuzzy Hough transform spectral alignment, variable selection, and parallel factor analysis, we can solve both the alignment and the confounding problem stated above. Using the outlined method, several different temporal concentration profiles can be resolved and the majority of the studied molecules and their respective fluxes can be attributed to these resolved kinetic profiles. The resolved time profiles hereby simplifies finding true biomarkers and bio-patterns for early detection of biological conditions as well as providing more detailed information about the studied biological system. The presented method represents a significant step forward in time-series analysis of biological 1H-NMR data as it provides almost full automation of the whole data analysis process and is able to analyze over 800 unique features per sample. The method is demonstrated using a 1H-NMR rat urine dataset from a toxicology study and is compared with a classical approach: COW alignment followed by bucketing.
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| 17. |
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| 18. |
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| 19. |
- Avagyan, Rozanna, et al.
(författare)
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Suspect screening of OH-PAHs and non-target screening of other organic compounds in wood smoke particles using HR-Orbitrap-MS
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 163, s. 313-321
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Tidskriftsartikel (refereegranskat)abstract
- Wood combustion has been shown to contribute significantly to emissions of polycyclic aromatic hydrocarbons and hydroxylated polycyclic aromatic hydrocarbons, compounds with toxic and carcinogenic properties. However, only a small number of hydroxylated polycyclic aromatic hydrocarbons have been determined in particles from wood combustion, usually compounds with available reference standards. In this present study, suspect and non-target screening strategies were applied to characterize the wood smoke particles from four different wood types and two combustion conditions with respect to hydroxylated polycyclic aromatic hydrocarbons and other organic compounds. In the suspect screening, 32 peaks corresponding to 12 monohydroxylated masses were tentatively identified by elemental composition assignments and matching of isotopic pattern and fragments. More than one structure was suggested for most of the measured masses. Statistical analysis was performed on the non-target screening data in order to single out significant peaks having intensities that depend on the wood type and/or combustion condition. Significant peaks were found in both negative and positive ionization modes, with unique peaks for each wood type and combustion condition, as well as a combination of both factors. Furthermore, structural elucidation of some peaks was done by comparing the spectra in the samples with spectra found in the spectral databases. Six compounds were tentatively identified in positive ionization mode, and 19 in negative ionization mode. The results in this present study demonstrate that there are significant overall differences in the chemistry of wood smoke particles that depends on both the wood type and the combustion condition used.
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| 20. |
- Bihagen, Erik, et al.
(författare)
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Elite mobility among college graduated men in Sweden : Skills, personality and family ties
- 2017
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Ingår i: Acta Sociologica. - : SAGE Publications. - 0001-6993 .- 1502-3869. ; 60:4, s. 291-308
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Tidskriftsartikel (refereegranskat)abstract
- Using Swedish registry data, we study the chances of mobility into the Swedish labour market elite for men who graduated in the years 1985-2005. The elite is defined as top earners within mid- and large sized firms and within the public sector organisations (henceforth, we use organisation for both firms and public organisations). Using discrete time event history models, we study the incidence of elite entry in terms of external recruitment and internal promotion. The choice of field of study and of college or university are important, as are personality and, to a limited extent, cognitive ability. What is most striking is that having kin in elite positions increases the chance of elite entry in general, and having parents in top positions in the same organisation increases the likelihood of internal promotion. In sum, elite entry among college-educated males is associated with a diversity of factors, suggesting that complex explanations for labour market success should be considered, where skills, personality, and family ties all seem to matter.
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| 21. |
- Borgh, Magnus, et al.
(författare)
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Correlation and spin polarization in quantum dots: Local spin density functional theory revisited
- 2005
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Ingår i: International Journal of Quantum Chemistry. - : Wiley. - 0020-7608 .- 1097-461X. ; 105:6, s. 817-825
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Tidskriftsartikel (refereegranskat)abstract
- Using quantum dot artificial atoms as a simple toy model, we reflect on the question of whether spin density functional theory (SDFT) can accurately describe correlation effects in low-dimensional fermion systems. Different expressions for the local density approximation of the exchange-correlation energy for the two-dimensional electron gas, such as the much-used functional of Tanatar and Ceperley, and the recent suggestion by Attaccalite et al., are compared with the results of a numerical diagonalization of the many-body Hamiltonian matrix in the limit of small electron numbers. For systems with degeneracies, as shown in the present work for the example of a spin triplet with S = 1, the direct comparison with configuration interaction (Cl) methods demonstrates that the spin representation of SDFT may, under certain circumstances, produce artificial energy splittings between states that belong to the same spin multiplet. For a singlet ground state with S = S = 0, however, the correlation functions of the Cl solutions confirm the spin-density wave states found earlier within the SDFT method.
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| 22. |
- Borgström, Magnus T., et al.
(författare)
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Towards Nanowire Tandem Junction Solar Cells on Silicon
- 2018
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Ingår i: IEEE Journal of Photovoltaics. - 2156-3381. ; 8:3, s. 733-740
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Tidskriftsartikel (refereegranskat)abstract
- The development of photovoltaics as a serious means of producing renewable energy has accelerated greatly in the last ten years, with prices for silicon-based solar cell systems dropping dramatically in the last few years. The next great opportunity for photovoltaics following this competitiveness in prices will be to enhance the cell and panel efficiencies. It is quite generally seen that the most viable platform on which this should be realized will be as augmented silicon solar cells, in which a top cell will be combined with the silicon bottom cell in a tandem configuration, by which the efficiency can be enhanced by a factor from 20% to 50%, depending on details of the approach. In this paper, we report on the status of one such approach, namely, with a top cell comprising III-V nanowires, connected to the bottom silicon cell in a two-terminal or four-terminal configuration. Among the most important opportunities, we show that a substrate-free growth, called Aerotaxy, offers a radical reduction in the total price picture. Besides the description of the key technical approaches, we also discuss the environmental issues.
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| 23. |
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| 24. |
- Csenki, Leonard, et al.
(författare)
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Proof of principle of a generalized fuzzy Hough transform approach to peak alignment of one-dimensional 1H NMR data
- 2007
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 389:3, s. 875-885
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Tidskriftsartikel (refereegranskat)abstract
- In metabolic profiling, multivariate data analysis techniques are used to interpret one-dimensional (1D) 1H NMR data. Multivariate data analysis techniques require that peaks are characterised by the same variables in every spectrum. This location constraint is essential for correct comparison of the intensities of several NMR spectra. However, variations in physicochemical factors can cause the locations of the peaks to shift. The location prerequisite may thus not be met, and so, to solve this problem, alignment methods have been developed. However, current state-of-the-art algorithms for data alignment cannot resolve the inherent problems encountered when analysing NMR data of biological origin, because they are unable to align peaks when the spatial order of the peaks changes—a commonly occurring phenomenon. In this paper a new algorithm is proposed, based on the Hough transform operating on an image representation of the NMR dataset that is capable of correctly aligning peaks when existing methods fail. The proposed algorithm was compared with current state-of-the-art algorithms operating on a selected plasma dataset to demonstrate its potential. A urine dataset was also processed using the algorithm as a further demonstration. The method is capable of successfully aligning the plasma data but further development is needed to address more challenging applications, for example urine data.
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| 25. |
- Dahlbäck, Cecilia, et al.
(författare)
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Long-term outcome of lymph vessel transplantation after chronic lymphorrhea
- 2021
-
Ingår i: Case Reports in Plastic Surgery and Hand Surgery. - : Informa UK Limited. - 2332-0885. ; 8:1, s. 169-174
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Tidskriftsartikel (refereegranskat)abstract
- A 52-year-old male patient developed a chronic fistula with excessive lymph leakage in the left axilla following removal of an enlarged lymph node with chronic local adipose tissue inflammation due to infection. After multiple surgeries, treatment with lymphatic vessel transplantation was successful. No recurrence occurred over 20 years of follow-up.
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| 26. |
- de Sousa, Pedro F. M., 1977-
(författare)
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Chemometrics : Unravelling information from complex data generated by modern instruments
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chemometrics is a discipline dedicated to solving problems arising from complicated analytical systems, combining statistics, mathematics, and computational programming languages.This thesis is based on the work developed in four scientific projects published as papers in scientific journals. The studies developed in these projects have been essentially focused on a data analysis perspective, interpreting complicated data by means of algorithms, employing chemometrical methodologies. Several chemometrical approaches, based on multivariate data analysis and signal processing algorithms have been studied and employed in each project. Most of the data analysis problems studied these projects are related to liquid chromatography hyphenated to mass spectrometry systems, including tandem mass spectrometry. One of the projects has been related to spectrophotometric data.Chromatographic peak shifts have been attributed to lack of control of the nominal chromatographic parameters. The purpose of the work presented in Paper I was to study retention time data, obtained experimentally by provoking peak shifts with controlled effects, to demonstrate that there are patterns associated with such changing factors affecting chromatographic processes. PCR (Principal Component Regression) models were calculated for each compound (98 compounds), using the retention time data of each compound as responses (y), and the retention time data of the remaining compounds as regressors (X). The results demonstrate that the peak shifts of each compound across samples are correlated with the peak shifts of the other compounds in the chromatographic data. This work confirmed a previous work, where an algorithm was developed to improve alignment of peaks in large number of complex samples, based on peak shift patterns.Partial Least Squares (PLS) is one of the mostly used chemometrics techniques. In the work presented in Paper II, a previously reported modified PLS algorithm was studied. This algorithm was developed with the purpose of not generating overfitting models with increasing noise in X, which happens with the classical PLS. However, the results in less-noisy data were not as good as the classical PLS. From this study, we have developed another modified algorithm that does not overfit with increasing noise in X, and it converges with the solutions of the classical PLS in less-noisy data.DNA adductomics is a recent field in omics that studies modifications in the DNA. The goal of the project in Paper III was to develop a program with a graphical interface to interpret LC-MS/MS using a data independent acquisition method, to identify adducts in DNA nucleosides. The results were compared with those performed manually. The program detected over 150 potential adducts whereas manually, in a previous work, only about 25 were found. This program can detect adducts automatically in a matter of seconds.Cancer has been associated with processes that are related to exposure to pollutants and the consumption of certain food products. This process has been related to electrophilic compounds that react with DNA (adducts). When DNA modifications occur, often defense mechanisms in the cell are triggered often leading to the rupture of the cell. Fragments of DNA (micronuclei) are then roaming in the blood stream. In this work (Paper IV), electrophilic additions to hemoglobin (adducts) and the expression of micronuclei in blood samples from 50 children were studied. One of the goals of the project was to find correlations between the adducts in hemoglobin and the expression of micronuclei. PLS was used to model the data. However, the results were not conclusive (R2 = 0.60), i.e., there may be some trends, but there are other variables not modelled that may influence the variance in expression of micronuclei.
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| 27. |
- Djuric Ilic, Danica, et al.
(författare)
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No zero burden assumption in a circular economy
- 2018
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 182, s. 352-362
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Tidskriftsartikel (refereegranskat)abstract
- A majority of previous studies on environmental problems caused by waste generation have focused on waste disposal issues without fully highlighting the primary reasons behind the problems. As a consequence, efforts to reduce these problems are usually directed towards the stakeholders that provide waste treatment and disposal instead of the stakeholders that contribute to waste generation. In order to detect connections between different problems of sustainability and to suggest measures which may contribute to their solutions, this study provides a simplified overview of the mechanisms behind waste generation and management. The results from the study show that the only way to eliminate problems of sustainability is to apply an upstream approach by dealing with the primary problems which occur in the early stages of the system (e.g. overconsumption of products, as well as use of finite resources, toxic materials, and non-recyclable materials). By dealing with these problems, the emergence of secondary problems would be prevented. Thereby, stakeholders who have the highest possibility to contribute to the sustainable development of the waste generation and management are the stakeholders from the origin of the product's life cycles, such as product developers, manufacturing companies, product users and policy makers. Different trade-off situations such as contradictions between economics, recyclability, energy efficiency, make it even harder to deal with issues of sustainability related to the system and to detect the stakeholders who may contribute to the development. One of the main conclusions from this study is that when transforming society towards a circular economy, the traditional view of separate systems for production and waste management must be changed. In order to refer to all problems of sustainability and also cover the top steps of the waste hierarchy, life cycle assessment of waste management should include manufacture and use of products ending up as waste. Waste entering the waste management system with “zero burden” by releasing the previous actors of the waste life cycle from any responsibility related to the environment (i.e. by shifting the total environmental burden into the waste management system), does not capture the problems with waste generation.
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| 28. |
- Envall, Ida, et al.
(författare)
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Existing evidence related to soil retention of phosphorus from on-site wastewater treatment systems in boreal and temperate climate zones : a systematic map
- 2023
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Ingår i: Environmental Evidence. - : Springer Nature. - 2047-2382. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: In Sweden there are nearly one million soil-based on-site wastewater treatment systems (OWTSs). OWTSs may contribute to eutrophication of surface waters, due to the discharge of phosphorus (P). Hence, in certain cases, a high P removal rate (up to 90%) of OWTSs is required by Swedish authorities. Since these requirements may have costly consequences to property owners, it is debated whether they are too strict. In this debate, it is often claimed that the soil retention of P occurring in the natural environments may be underestimated by authorities. Soil retention is the inhibition of the transport of P through the ground, due to different chemical, physical and biological processes occurring there. These processes make the P transport slower, which may reduce the unwanted impact on receiving water bodies. However, the efficiency of soil retention of P remains unclear. The objective of this systematic map was to collect, code, organise and elucidate the relevant evidence related to the topic, to be able to guide stakeholders through the evidence base, and to support future research synthesising, commissioning, and funding. The systematic map was carried out in response to needs declared by the Swedish Agency for Marine and Water Management but the conclusions should be valid for a wider range of countries across boreo-temperate regions.Methods: Searches were made for peer-reviewed and grey literature using bibliographic databases, search engines, specialist websites, and stakeholder contacts. The references were screened for relevance according to a predefined set of eligibility criteria. A detailed database of the relevant studies was compiled. Data and metadata that enable evaluation and discussion of the character and quality of the evidence base were extracted and coded. Special focus was placed on assessing if existing evidence could contribute to policy and practice decision making. Descriptive information about the evidence base was presented in tables and figures. An interactive evidence atlas and a choropleth were created, displaying the locations of all studies.Review findings: 234 articles out of 10,797 screened records fulfilled the eligibility criteria. These articles contain 256 studies, performed in the field or in the laboratory. Six different study types were identified, based on where the measurements were conducted. Most studies, including laboratory studies, lack replicates. Most field studies are observational case studies.Conclusions: It is not possible to derive valid generic measures of the efficiency of soil retention of P occurring in the natural soil environment from available research. Neither does the evidence base allow for answering the question of the magnitude of the potential impact of OWTSs on the P concentration in recipients on a general basis, or under what conditions OWTSs generally have such an impact. A compilation of groundwater studies may provide examples of how far the P may reach in x years, but the number of groundwater studies is insufficient to draw any general conclusions, given the complexity and variability of the systems. Future research should strive for replicated study designs, more elaborate reporting, and the establishment of a reporting standard.
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| 29. |
- Espinet-Gonzalez, Pilar, et al.
(författare)
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Radiation Tolerant Nanowire Array Solar Cells
- 2019
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 13:11, s. 12860-12869
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Tidskriftsartikel (refereegranskat)abstract
- Space power systems require photovoltaics that are lightweight, efficient, reliable, and capable of operating for years or decades in space environment. Current solar panels use planar multijunction, III-V based solar cells with very high efficiency, but their specific power (power to weight ratio) is limited by the added mass of radiation shielding (e.g., coverglass) required to protect the cells from the high-energy particle radiation that occurs in space. Here, we demonstrate that III-V nanowire-array solar cells have dramatically superior radiation performance relative to planar solar cell designs and show this for multiple cell geometries and materials, including GaAs and InP. Nanowire cells exhibit damage thresholds ranging from ∼10-40 times higher than planar control solar cells when subjected to irradiation by 100-350 keV protons and 1 MeV electrons. Using Monte Carlo simulations, we show that this improvement is due in part to a reduction in the displacement density within the wires arising from their nanoscale dimensions. Radiation tolerance, combined with the efficient optical absorption and the improving performance of nanowire photovoltaics, indicates that nanowire arrays could provide a pathway to realize high-specific-power, substrate-free, III-V space solar cells with substantially reduced shielding requirements. More broadly, the exceptional reduction in radiation damage suggests that nanowire architectures may be useful in improving the radiation tolerance of other electronic and optoelectronic devices.
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| 30. |
- Fachrizal, Reza, 1993-, et al.
(författare)
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Optimal PV-EV sizing at solar powered workplace charging stations with smart charging schemes considering self-consumption and self-sufficiency balance
- 2022
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 307
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Tidskriftsartikel (refereegranskat)abstract
- The integration of photovoltaic (PV) systems and electric vehicles (EVs) in the built environment, including at workplaces, has increased significantly in the recent decade and has posed new technical challenges for the power system, such as increased peak loads and component overloading. Several studies show that improved matching between PV generation and EV load through both optimal sizing and operation of PV-EV systems can minimize these challenges. This paper presents an optimal PV-EV sizing framework for workplace solar powered charging stations considering load matching performances. The proposed optimal sizing framework in this study uses a novel score, called self-consumption-sufficiency balance (SCSB), which conveys the balance between self-consumption (SC) and self-sufficiency (SS), based on a similar principle as the F1-score in machine learning. A high SCSB score implies that the system is close to being self-sufficient without exporting or curtailing a large share of local production. The results show that the SCSB performance tends to be higher with a larger combined PV-EV size. In addition to presenting PV-EV optimal sizing at the workplace charging station, this study also assesses a potential SC and SS enhancement with optimal operation through smart charging schemes. The results show that smart charging schemes can significantly improve the load matching performances by up to 42.6 and 40.8 percentage points for SC and SS, respectively. The smart charging scheme will also shift the combined optimal PV-EV sizes. Due to its simplicity and universality, the optimal sizing based on SCSB score proposed in this study can be a benchmark for future studies on optimal sizing of PV-EV system, or distributed generation-load in general.
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| 31. |
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| 32. |
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| 33. |
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| 34. |
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| 35. |
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| 36. |
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| 37. |
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| 38. |
-
Gender and Change : Power, Politics and Everyday Practices
- 2012
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Research on gender aims to contribute towards a better society with the help of scientific tools. Change is therefore a key concept in gender studies. With a wide range of theoretical frameworks, methodological approaches and empirical materials from Sweden, Norway and Iceland, this book investigates how gender relations are shaped, reproduced, and challanged. Collectively, the papers in this volume point to where we are heading in terms of gender relations. Where are the seeds to change, and how does power make possible or impede on change?
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| 39. |
- Grigoriadis, Anastasios, et al.
(författare)
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Effect of Sudden Deprivation of Sensory Inputs From Periodontium on Mastication
- 2019
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the effect of sudden deprivation of sensory inputs from the periodontium on jaw kinematics and time-varying activation profile of the masseter muscle.Methods: Fourteen (age range: 22-26 years; four men) healthy and natural dentate volunteers participated in a single experimental session. During the experiment, the participants were asked to eat six hard visco-elastic test food models, three each before and after an anesthetic intervention. The movements of the jaw in three dimensions and electromyographic (EMG) activity of the masseter muscle on the chewing side were recorded.Results: The results of the study showed no significant differences in the number of chewing cycles (P = 0.233) and the duration of chewing sequence (P = 0.198) due to sudden deprivation of sensory inputs from the periodontium. However, there was a significant increase in the jaw opening velocity (P = 0.030) and a significant increase in the duration of occlusal phase (P = 0.004) during the anesthetized condition. The EMG activity of the jaw closing phase was significantly higher during the control condition [116.5 arbitrary units (AU)] than anesthetized condition (93.9 AU). The temporal profile of the masseter muscle showed a biphasic increase in the excitatory muscle drive in the control condition but this increase was virtually absent during the anesthetized condition.Conclusion: Sudden deprivation of sensory inputs from the periodontium affects the jaw kinematics and jaw muscle activity, with a clear difference in the time-varying activation profile of the masseter muscle. The activation profile of the masseter muscle shows that periodontal mechanoreceptors contribute to approximately 20% of the EMG activity during the jaw closing phase.
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| 40. |
- Gustafsson, Mattias, 1972-
(författare)
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Evaluation of energy conserving measures in buildings connected to a district heating system : case studies in Gävle, Sweden
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When different energy conserving measures are implemented for reducing energy use in buildings and the buildings are connected to district heating systems, it is important that an overall system analysis is made which takes into account the effects of total change of energy use due to the energy conserving measures.The method applied in this thesis uses hourly production data for the different production units in the district heating system in Gävle, Sweden. The merit order of the different production units is dependent on the electricity spot market price. To calculate the merit order, hourly data for the electricity price is used. The marginal production unit can then be determined for each hour of the investigated year.This thesis analyzes five different energy conserving measures in a multi-dwelling building regarding how they affect the marginal production units in the district heating system. For CO2 emission evaluations, two different combinations of heat and electricity conserving measures are compared to installation of an exhaust air heat pump. This thesis also analyzes how the configuration of the electric meter affects the measured amount of self-consumed and produced excess electricity for a single-family house and for two multi-dwelling buildings of different sizes.The results show that the use of electricity is the most important objective to consider. The increased use of electricity for operation of the heat pump contributes to an increase of global CO2 emissions and the electricity produced by the solar photovoltaic installation contributes to a decrease of global CO2 emissions.The results also show that the configuration of the electric meter is important for the single-family house but negligible for the multi-dwelling buildings. The amount of produced excess electricity is high for all buildings, which means that the economic value of produced excess electricity is important for a profitable installation.
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| 41. |
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| 42. |
- Hansson, Emma, et al.
(författare)
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Neuropeptide levels in Dercum's disease (adiposis dolorosa).
- 2012
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Ingår i: Reumatismo. - 0048-7449. ; 64:3, s. 134-141
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Tidskriftsartikel (refereegranskat)abstract
- Dercum's disease (adiposis dolorosa) is characterised by adiposity and chronic pain in the adipose tissue. It has been proposed that conditions encompassing chronic pain have altered concentrations of neuropeptides involved in pain transmission. The aim of this investigation was to examine whether patients with Dercum's disease have abnormal concentrations of different neuropeptides. In cerebrospinal fluid (CSF) and in plasma (P) from 53 patients with Dercum's disease substance P-like immunoreactivity (SP-LI), neuropeptide Y-like immunoreactivity (NPY-LI), b-endorphin-like immunoreactivity (b-END-LI), calcitonin gene-related peptidelike immunoreactivity (CGRP-LI), met-enkephalin-like immunoreactivity (m-ENK-LI), vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI), somatostatin (SOM-LI), g2-melanocyte-stimulating hormone-like immunoreactivity (g2-MSH-LI), and dynorphin-like immunoreactivity (DYN-LI) were measured. Three of the substances were also measured in a control group. The CSF concentration of SP was statistically significantly lower in the Dercum group than in the control group, whereas NPY-LI and b-END-LI were borderline statistically significantly lower and higher, respectively, in Dercum patients compared to controls. Compared with reference values, CSF-MSH-LI levels were slightly elevated and CSF-NPY-LI levels were slightly lowered in the Dercum group. The other substances in both CSF and plasma were within the reference values with a high degree of statistical significance. In conclusion, altered levels of neuropeptides that have previously been seen in different pain conditions cannot clearly be demonstrated in Dercum's disease.
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| 43. |
- Hansson, Helena, et al.
(författare)
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Dynamic hollow-fibre liquid phase microextraction of dinitrophenols from human plasma: Optimization of an extraction flow system using experimental design methodology
- 2009
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Ingår i: Talanta. - : Elsevier. - 0039-9140 .- 1873-3573. ; 79:3, s. 633-638
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Tidskriftsartikel (refereegranskat)abstract
- The utility of a dynamic hollow-fibre liquid phase microextraction method (optimized using a four-variable experimental design and response surface modelling) for extracting dinitrophenolic compounds from human plasma samples was evaluated. The investigated variables were donor phase salt concentration (10–400 mM), donor phase pH (2–6), acceptor phase pH (7–12), and donor/acceptor phase flow rates (30/7.5 to 70/17.5 μL min−1). Four dinitrophenol pesticides were used as model substances at concentrations of 0.1 μg mL−1 in spiked human plasma samples. Extraction efficiencies ranging from 42 to 77% with RSDs below 9 were achieved with the optimized method. The flow rate and acceptor pH were shown to strongly affect the extraction efficiency for all compounds, while the donor phase pH and salt concentration had minor effects. With a well-defined acceptor phase pH and flow rate the system exhibited high robustness. The limits of quantification for the investigated compounds, using the presented extraction method followed by liquid chromatography/electrospray ionization mass spectrometry in selected ion monitoring mode, ranged from 0.05 to 0.1 μg mL−1 plasma.
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| 44. |
- Hedlin, Maria, et al.
(författare)
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Challenging Gender in Teacher Education
- 2012
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Ingår i: Gender and change. - Karlstad : Karlstad University Press. - 9789186637057 ; , s. 113-126
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 45. |
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| 46. |
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| 47. |
- Hedlin, Maria, et al.
(författare)
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Fallet med de störande manliga studenterna: en situation tolkad utifrån fyra olika förklaringsmodeller
- 2015
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Ingår i: Utbildning och Lärande / Education and Learning. - Skövde : Högskolan i Skövde. - 2001-4554. ; 9:1, s. 116-133
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we use a situation in a teacher education program as the basis to problematize different understandings of ”feminine” and ”masculine”. Within the program, the arrogant and condescending behavior of a group of male student teachers towards their female classmates was discussed. The men were oriented towards each other in a manner that excluded women. They demonstrated their disinterest in the seminars and they disturbed the on-going education. A group of teacher educators considered an explanation for the male students’ behavior, saying that because the men were in a program with predominantly female students and many female teachers, they were supposed to have a natural need to socialize with each other and to underscore that they were men. They would therefore need to assert themselves and rebel against the women within the program. In this article we will discuss this explanation, as well as a sex-role explanation, an individual-oriented explanation and finally an explanatory model that draws on critical masculinity studies. By situating these explanations in time and space, we show how knowledge from the field of gender studies can increase the likelihood that teacher education is a place of equal participation and inclusion.
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| 48. |
- Hedlin, Maria, Docent, 1961-, et al.
(författare)
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Fun guy and possible perpetrator : an interview study of how men are positioned within early childhood education and care
- 2019
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Ingår i: Education Inquiry. - : Taylor & Francis Group. - 2000-4508. ; 10:2, s. 95-115
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Tidskriftsartikel (refereegranskat)abstract
- Many countries call for more men to be teachers in early childhood education and care (ECEC). In Sweden, the issue has been discussed since the early 1970s, but despite these discussions there is little Swedish research that examines the notions and expectations associated with male teachers. International research has found that perceptions of men in ECEC can be very ambivalent and that physical contact between the male educator and children is a sensitive issue. By focusing on the interaction between educators and children, the purpose of this study is to investigate gender-specific beliefs about male preschool teachers. The empirical material consists of interviews with 50 informants. Of these, 17 are men and 33 are women. The results show that “the fun guy” and “the possible perpetrator” are two gender-specific positions that male informants are subjected to. The article discusses how men take up and resist the two positions, and argues for the need to further challenge gendered stereotypes in preschools.
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| 49. |
- Hedlin, Maria, Docent, 1961-, et al.
(författare)
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Fussy girls and chattering women : The construct and subordination of femininity in preschool teacher training
- 2018
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Ingår i: Early Child Development and Care. - : Routledge. - 0300-4430 .- 1476-8275. ; 188:2, s. 220-230
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden, as in Western countries generally, most preschool teachers are women. This fact sometimes leads to the assumption that preschools are “feminine”, and that this might be bad for boys. We challenge this assumption. Using a gender critical approach we have studied preschool student teachers. “Femininity” might be used as a rhetorical and demeaning stereotype by them. Women and femininity however, are not interchangeable concepts. Failure to acknowledge this can pave the way for subtle sexism against girls and women. Our argument is supported by ethnographic observations and interviews with student teachers. By means of a Foucauldian genealogical analysis we uncover the conditions of possibility for two long-lasting feminine stereotypes. One stereotype argues that young girls should never fuss. The other claims that women are chattering gossipers. Our study shows that these archaic notions persist in Swedish preschool teacher training, despite its long tradition of work for gender equality.
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| 50. |
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