| 1. |
- Herrmann, Björn, et al.
(författare)
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Emergence and Spread of Chlamydia trachomatis Variant, Sweden
- 2008
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 14:9, s. 1462-1465
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Tidskriftsartikel (refereegranskat)abstract
- A variant of Chlamydia trachomatis that had escaped detection by commonly used systems was discovered in Sweden in 2006. In a nationwide study, we found that it is now prevalent across Sweden, irrespective of the detection system used. Genetic analysis by multilocus sequence typing identified a predominant variant, suggesting recent emergence.
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| 2. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 3. |
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| 4. |
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| 5. |
- Diener, Silvia, et al.
(författare)
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Accelerated carbonation of ashes and steel slags in a landfill cover construction
- 2008
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Ingår i: Proceedings of Second International Conference on Accelerated Carbonation for Environmental and Materials Engineering. - : University of Rome "La Sapienza". ; , s. 389-400
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Konferensbidrag (refereegranskat)abstract
- Fly ash from biofuel incineration and slags from steel production were used in two full scale applications of cover constructions on municipal solid waste (MSW) landfills. The long-term stability of the cover materials is studied in a designed laboratory experiment. The impact of six environmental factors on accelerated carbonation is investigated over a period of three years. Leaching behaviour, acid neutralization capacity, mineral composition (XRD) and thermo gravimetrical behaviour (TG) are tested after different periods of ageing under different conditions. By now samples were taken after three and ten months of ageing. Multivariate data analysis was used for data evaluation. The results indicate the factors material, ageing time and carbon dioxide content of the atmosphere to be most relevant.
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| 6. |
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| 7. |
- Diener, Silvia, et al.
(författare)
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Mineral transformations in steel slag used as landfill cover liner material
- 2007
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Ingår i: SARDINIA 2007. - Cagliari : CISA, Environmental Sanitary Engineering Centre. - 9788862650038
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Konferensbidrag (refereegranskat)abstract
- In Europe, 15.2 million tonnes of steel slags have been generated in 2004 (Euroslag, 2006) out if which almost 6 million tonnes came from electric arc furnace (EAF) steelmaking and secondary metallurgical processes. In the presented project from Luleå University of Technology, two types of EAF slag and one slag originating from secondary metallurgical processes named ladle slag are investigated. The chemical and physical properties of these slags have been studied in detail (Herrmann, 2006; Andreas et al., 2005). For utilising steel slags in the liner of a landfill cover the long-term stability of the minerals is of great importance. Therefore, the ageing of steel slag minerals is evaluated with the help of a laboratory experiment. Particularly, the research questions, the experimental set-up and the methodology are presented. The present paper is part of a research project of the Division of Waste Science and Technology at Luleå University of Technology, Sweden in cooperation with Uddeholm Tooling AB, Hagfors municipality and MiMeR (Mineral and Metal Recycling Research Centre). It is investigated if steel slags are stable as a landfill cover liner material. The long-term stability is evaluated by determining the factors influencing the mineralogy of the slags and possible mineral transformations through ageing under the environmental conditions in a liner. The experiment includes two similar types of EAF slag and one ladle slag. Each steel slag sample is made by mixing 50% EAF slag and 50% ladle slag, addition of water and compaction. The specimens are stored in boxes under different atmospheric conditions. A reduced multivariate design has been chosen to determine the impact of different factors on the slag mineralogy. The factors that are varied in the experiment are relative humidity, carbon dioxide and temperature of the atmosphere surrounding the slag material as well as ageing time and the quality of the water used for sample making (see table 1). Table 1. Factorial design for ageing experiment of steel slagsLowMiddleHighRelative humidity30% -100%Carbon dioxide content0.036 (air)20 % * 100 %Temperature5 °C30 °C60 °CTime 1 month6 months1 yearWater quality destilled water -LeachateThe ageing of minerals is expected to initiate mineral transformations in steel slags. Primary phases will alter into secondary mineral phases. Changes in mineralogy can influence the stability of the liner. To evaluate mineralogy and properties of the aged steel slag, different analyses will be performed after the storage time of the specimens. X-ray diffraction and scanning electron microscopy as well as shear strength, acid neutralisation capacity and cation exchange capacity will be included. A possible mineral transformation for an alkaline material as steel slags can be the reaction of calcium ions from calcium silicates with the carbon dioxide resulting in the precipitation of calcium carbonate. Through this carbonation reaction, the transport of carbon dioxide into the bulk of the specimen could be hindered by the reaction products. Therefore, surface morphology can influence mineral transformations. First results and evaluations will be presented at the conference. REFERENCES Andreas L., Herrmann I., Lidstrom-Larsson M. & Lagerkvist A. (2005) Physical properties of steel slag to be reused in a landfill cover, Sardinia 2005, Tenth International Waste Management and Landfill Symposium, S. Margherita di Pula, Cagliari, Italy; 3 - 7 October 2005Euroslag (2006) Legal status of Slags. Position Paper. January 2006. The European Slag Association - EUROSLAG. Duisburg, Germany.Herrmann I. (2006). Use of Secondary Construction Material in Landfill Cover Liners. Licentiate Thesis. Luleå University of Technology, Sweden.
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| 8. |
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| 9. |
- Edvinsson, Tomas, et al.
(författare)
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Intramolecular charge-transfer tuning of perylenes : Spectroscopic features and performance in Dye-sensitized solar cells
- 2007
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 111:42, s. 15137-15140
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Tidskriftsartikel (refereegranskat)abstract
- Five novel perylene molecules with different intramolecular charge-transfer (ICT) characters have been synthesized. The relation between the ICT character for different donating groups and the results for their electro- and photochemical properties as well as their performance in nanostructured dye-sensitized solar cells (nDSC) are reported. With the stronger donors, we obtain a shift of the lowest unoccupied molecular orbital (LUMO) to more negative potential versus normal hydrogen electrode (NHE) as well as an increase the charge separation in the dye upon excitation. Ab initio calculations were used to analyze the effects on orbital energies and electron distribution with the different donors. Incorporating the dyes in nDSCs, we see a drastical improvement in the performance for the more polar dyes. In particular, we find a much improved photovoltage because of higher LUMO levels, allowing conduction band tuning in the TiO2 as well as a contribution from the permanent dipoles in the dyes. The photocurrent improves remarkably with increasing ICT character of the dyes. The external quantum efficiency reached over 70%, and the overall solar-to-electrical energy conversion efficiency was improved to almost 4% for the dye with highest ICT character, which can be compared with devices with the standard N719 dye (Ru(dcbPY)(2)(NCS)(2)) showing 6% under similar conditions. The performance is a significant improvement compared to previous reports for perylenes and lifts the performance from modest to promising. Initial stability tests show that the dye with the highest performance was spectrally stable after more than 2000 h of irradiation in a solar-cell device.
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| 10. |
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| 11. |
- Göransson, Ulf, et al.
(författare)
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The Conserved Glu in the Cyclotide Cycloviolacin O2 Has a Key Structural Role
- 2009
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Ingår i: ChemBioChem. - : Wiley. - 1439-4227 .- 1439-7633. ; 10:14, s. 2354-2360
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Tidskriftsartikel (refereegranskat)abstract
- Cyclotides are a large family of plant peptides that are characterised by a head-to-tail circular backbone and three disulfide bonds that are arranged in a cystine knot. This unique structural feature, which is referred to as a cyclic cystine knot, gives the cyclotides remarkable stability against chemical and biological degradation. In addition to their natural function as insecticides for plant defence, the cyclotides have a range of bioactivities with pharmaceutical relevance, including cytotoxicity against cancer cell lines. A glutamic acid residue, aside from the invariable disulfide array, is the most conserved feature throughout the cyclotide family, and it has recently been shown to be crucial for biological activity. Here we have used solution-state NMR spectroscopy to determine the three-dimensional structures of the potent cytotoxic cyclotide cycloviolacin O2, and an inactive analogue in which this conserved glutamic acid has been methylated. The structures of the peptides show that the glutamic acid has a key structural role in coordinating a set of hydrogen bonds in native cycloviolacin O2; this interaction is disrupted in the methylated analogue. The proposed mechanism of action of cyclotides is membrane disruption and these results suggest that the glutamic acid is linked to cyclotide function by stabilising the structure to allow efficient aggregation in membranes, rather than in a direct interaction with a target receptor.
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| 12. |
- Herrmann, Anders, et al.
(författare)
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Key role of glutamic acid for the cytotoxic activity of the cyclotide cycloviolacin O2
- 2006
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Ingår i: Cellular and Molecular Life Sciences (CMLS). - : Springer Science and Business Media LLC. - 1420-682X .- 1420-9071. ; 63:2, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- Cyclotides are cyclic plant proteins with potent cytotoxic effects. Here we systematically probed the importance of surface-exposed charged amino acid residues of the cyclotide cycloviolacin O2, using a strategy involving chemical modifications. We show that the single glutamic acid plays a key role for the cytotoxicity: methylation of this residue produced a 48-fold decrease in potency. Virtually no change in potency was observed when masking the single arginine residue using 1,2-cyclohexanedione, while acetylation of the two lysine residues reduced the potency 3-fold. The derivative with modifications at both arginine and lysine residues showed a 7-fold loss of potency. In addition, we show that the activity is dependent on an intact disulfide network and that the short sequences between the six cysteine residues, that is, the backbone loops, are devoid of cytotoxic activity.
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| 13. |
- Herrmann, Anders, 1976-
(författare)
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Structure and Activity of Circular Plant Proteins : Cytotoxic Effects of Viola Cyclotides
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cyclotides are a family of small and macrocyclic proteins that have been found in Violacaee and Rubiaceae plant species. These proteins contain a cystine knot: two disulfides bonds together with their connecting peptide backbone form an embedded ring which is penetrated by a third disulfide bond. The cyclotides have been attributed a wide range of biological activities, which in combination with their chemical stability and structural plasticity have made them attractive tools for pharmaceutical applications. The sequence of eleven novel cyclotides, vibi A-K, from Viola biflora was determined by the use of both chemical (extraction and characterization) and molecular biology (cDNA analyses) approaches. A clear discrepancy in the results from the two methods was observed. Additionally, one novel cyclotide, vodo O, was isolated from Viola odorata. To correlate cytotoxic potency to sequence, vodo O and vibi D, E, G and H were tested on a lymphoma cell line. Based on the presence or absence of a cis-Pro bond, the cyclotides are divided into the Möbius and bracelet subfamilies. The bracelet proteins have a higher net charge and are more cytotoxic potent than the Möbius ones. To explore these differences, charged and hydrophobic residues in varv A (Möbius) and cycloviolacin O2 (bracelet) were chemically modified and tested for their cytotoxicity. The net-charge of the two proteins was not important for the potency. The Glu residue in cycloviolacin O2 was crucial, while this residue was of minor importance in varv A. Oxidation of the single Trp residue declined the potency significantly in both proteins. To evaluate how the surface properties correlate to the degree of cytotoxic potency, models of all cyclotides hitherto tested were constructed by homology modelling. Calculations showed that the membrane orientation of varv A and cycloviolacin O2 differed significantly, which might explain their difference in potency
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| 14. |
- Herrmann, Anders, et al.
(författare)
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The alpine violet, Viola biflora, is a rich source of novel cyclotides with potent cytotoxic cytotoxicity
- 2008
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Ingår i: Phytochemistry. - : Elsevier BV. - 0031-9422 .- 1873-3700. ; 69:4, s. 939-952
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Tidskriftsartikel (refereegranskat)abstract
- The cyclotides are currently the largest known family of head-to-tail cyclic proteins. The complex structure of these small plant proteins, which consist of approximately 30 amino acid residues, contains both a circular peptide backbone and a cystine knot, the combination of which produces the cyclic cystine knot motif. To date, cyclotides have been found in plants from the Rubiaceae, Violaceace and Cucurbitaceae families, and are believed to be part of the host defence system. In addition to their insecticidal effect, cyclotides have also been shown to be cytotoxic, anti-HIV, antimicrobial and haemolytic agents. In this study, we show that the alpine violet Viola biflora (Violaceae) is a rich source of cyclotides. The sequences of 11 cyclotides, vibi A-K, were determined by isolation and MS/MS sequencing of proteins and screening of a cDNA library of V. biflora in parallel. For the cDNA screening, a degenerate primer against a conserved (AAFALPA) motif in the cyclotide precursor ER signal sequence yielded a series of predicted cyclotide sequences that were correlated to those of the isolated proteins. There was an apparent discrepancy between the results of the two strategies as only one of the isolated proteins could be identified as a cDNA clone. Finally, to correlate amino acid sequence to cytotoxic potency, vibi D, E, G and H were analysed using a fluorometric microculture cytotoxicity assay using a lymphoma cell line. The IC50-values of the bracelet cyclotides vibi E, G and H ranged between 0.96 and 5.0 mu M while the Mobius cyclotide vibi D was not cytotoxic at 30 mu M.
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| 15. |
- Herrmann, Inga, et al.
(författare)
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Hydraulic conductivity of fly ash : sewage sludge mixes for use in landfill cover liners
- 2009
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 43:14, s. 3541-3547
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Tidskriftsartikel (refereegranskat)abstract
- Secondary materials could help meeting the increasing demand of landfill cover liner materials. In this study, the effect of compaction energy, water content, ash ratio, freezing, drying and biological activity on the hydraulic conductivity of two fly ash - sewage sludge mixes was investigated using a 27-1 fractional factorial design. The aim was to identify the factors that influence hydraulic conductivity, to quantify their effects and to assess how a sufficiently low hydraulic conductivity can be achieved. The factors compaction energy and drying, as well as the factor interactions material×ash ratio and ash ratio×compaction energy affected hydraulic conductivity significantly (α = 0.05). Freezing on 5 freeze-thaw cycles did not affect hydraulic conductivity. Water content affected hydraulic conductivity only initially. The hydraulic conductivity data were modelled using multiple linear regression. The derived models were reliable as indicated by R2adjusted values between 0.75 and 0.86. Independent on the ash ratio and the material, hydraulic conductivity was predicted to be between 1.7 × 10-11 m s-1 and 8.9 × 10-10 m s-1 if the compaction energy was 2.4 J cm-3, the ash ratio between 20 and 75 % and drying did not occur. Thus, the investigated materials met the limit value for non-hazardous waste landfills of 10-9 m s-1.
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| 16. |
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| 17. |
- Herrmann, Inga, et al.
(författare)
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Reuse of steel industry slag in a landfill top cover
- 2006
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Ingår i: Abstract proceedings of the 4th Intercontinental Landfill Research Symposium, [June 14th to 16th 2006, Gällivare, Sweden]. - Luleå : Luleå tekniska universitet. ; , s. 88-89
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Innings, Åsa, et al.
(författare)
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Multiplex real-time PCR targeting the RNase P RNA gene for detection and identification of Candida species in blood
- 2007
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:3, s. 874-880
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a single-tube multiplex real-time PCR method for the detection of the eight most common Candida species causing septicemia: Candida albicans, C. dubliniensis, C. famata, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis. The method developed targets the RNase P RNA gene RPR1. Sequences of this geiie were determined for seven of the Candida species and showed surprisiRgly large sequence variation. C. glabrata was found to have a gene that was five times longer gene than those of the other species, and the nucleotide sequence similarity between C. krusei and C. albicans was as low as 55%. The multiplex PCR contained three probes that enabled the specific detection of C. albicans, C. glabrata, and C. krusei and a fourth probe that allowed the general detection of the remaining species. The method was able to detect 1 to 10 genome copies when the detection limit was tested repeatedly for the four species C. albicans, C. glabrata, C. krusei, and C. guilliermondii. No significant difference in the detection limit was seen when the multiplex format was compared with single-species PCR, i.e., two primers and one probe. The method detected eight clinically relevant Candida species and did not react with other tested non-Candida species or human DNA. The assay was applied to 20 blood samples from nine patients and showed a sensitivity similar to that of culture.
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| 19. |
- Löfdahl, Margareta, et al.
(författare)
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Klamydia hos kvinnor i Sverige : Smittspårning och rutiner för rapportering måste förbättras
- 2008
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 105:44, s. 3116-3120
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Tidskriftsartikel (refereegranskat)abstract
- Despite usage of considerable resources the number of detected chlamydia cases in Sweden has increased by 300% since 1997. The reported rates of diagnosed chlamydia cases per 100,000 inhabitants differs about two-fold between Swedish counties. This study analyzed chlamydia testing in women from nine Swedish counties with different reported rates of diagnosed cases between 1997 and 2005. Testing was highest in the age group 20-24 years old, where the proportion annually tested ranged between 20% and 40%. Of all detected chlamydia cases in Sweden with complete information (70%) “screening” was reported as the reason for testing in 12% of women in 2005 while partner notification was given as the reason in 40%. Corresponding figures for men were 3% and 64%, respectively. Partner notification is the most important reason for case detection in both women and men, while “screening” was a less common reason. At this level of screening, no impact on chlamydia transmission in the population would be expected.
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| 20. |
- Månsson, Niclas, 1965-
(författare)
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Negativ socialisation : Främlingen i Zygmunt Baumans författarskap
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this dissertation I address the question of why some social groups classify some people and groups as strangers. To answer the question I focus the stranger in the writings of the Polish sociologist Zygmunt Bauman.According to Bauman, the social construction of the stranger cannot be compared with the asymmetrical relation between an in-group and an out-group. An in-group stands for friends and proximity. It considers the out-group as the enemy at a distance. The hierarchical and a reciprocal relationship that exists between the in-group and the out-group is a part of the social order. The stranger, on the other hand, is constructed in the ambivalent position between the in-group and the out-group. Since there is no room for the stranger in an orderly world she has to be dealt with in a way that keeps the world free from incongruity.Since Bauman considers the moral consequence of cultural classification, his work is also relevant for the question of living with the stranger. Leaving the Occidental rational tradition in favour of a phenomenological tradition, Bauman offers a view that considers the encounter with the stranger as a moral meeting. Highlighting responsibility, instead of social arrangements, law or tradition, Bauman visualises the stranger as a moral subject and not as aparticular social type, one who is constantly out of placeThe theoretical considerations of the social making of the stranger, and the moral understanding of living for the stranger, contribute to a deeper understanding about the institutional origins of social marginalisation and cultural exclusion.
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| 23. |
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