1. |
- Sjöström, Margareta, et al.
(author)
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How do you spell development? : a study of a literacy campaign in Ethiopia
- 1983
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Book (other academic/artistic)abstract
- The problem of illiteracy has been the object of many studies during recent decades. In Ethiopia, a country which reports one of the lowest literacy rates in Africa, the Yemissrach Dimts Literacy Campaign (YDLC) was started in 1962. Its activities were concentrated to rural areas and directed primarly towards adults. This study is an evaluation of the Campaign. The investigation was conducted between 1974-1976 with the purpose of describing and analysing Campaign activities, focusing on student achievement, the teaching process, and benefits experienced by participants of the Campaign. Another important objective was to consider the role of the Campaign within a wider socio-economic and political context.
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2. |
- Sjöström, Margareta, 1932-, et al.
(author)
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Literacy and development : A study of Yemissrach Dimts literacy campaign in Ethiopia
- 1982
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Doctoral thesis (other academic/artistic)abstract
- The problem of illiteracy has been the object of many studies during recent decades. In Ethiopia, a country which reports one of the lowest literacy rates in Africa, the Yemissrach Dimts Literacy Campaign (YDLC) was started in 1962. Its activities were concentrated to rural areas and directed primarily towards adults. The present study is an evaluation of the Campaign. The investigation was conducted between 1974-1976 with the purpose of describing and analysing Campaign activities, focussing on student achievement, the teaching process, and benefits experienced by participants of the Campaign. Another important objective was to consider the role of the Campaign within a wider socio-economic and political context. The main sample consisted of 466 literacy students in eight different schools from the regions of Wollo, Wollega, Shoa and Gamu Gofa. An additional group of 66 adult villagers also took part in the interview studies. In addition to the interviews, researchers' methodology included achievement testing and classroom observations. The results of our study indicate that students became literate after one to two years at the literacy school. However, individual participants stated that they had not experienced substantial benefits arising from their literacy skills. When students were taught to read in Amharic campaign teachers used a combination of synthetic and analytic methods. The influence of traditional reading methods was clearly visible. Motivation for sending children to school appeared fairly strong, but adults declared that it was seldom possible for themselves to attend school; Contrary to what one might expect traditional values did not seem to be the reason for this. In the case of women and girls, however, tradition was probably a major obstacle. YDLC as an educative phenomenon is also discussed in an overall development perspective. A critical appraisal of evaluative strategies for development programmes in included.
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5. |
- Aspholm-Hurtig, Marina, et al.
(author)
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Functional adaptation of BabA, the H. pylori ABO blood group antigen binding adhesin.
- 2004
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In: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 305:5683, s. 519-22
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Journal article (peer-reviewed)abstract
- Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in babA sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to babA diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O-dominant human populations.
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6. |
- Aspholm, Marina, et al.
(author)
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Helicobacter pylori adhesion to carbohydrates
- 2006
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In: Methods in Enzymology. - 0076-6879 .- 1557-7988. ; 417, s. 293-339
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Journal article (peer-reviewed)abstract
- Adherence of bacterial pathogens to host tissues contributes to colonization and virulence and typically involves specific interactions between bacterial proteins called adhesins and cognate oligosaccharide (glycan) or protein motifs in the host that are used as receptors. A given pathogen may have multiple adhesins, each specific for a different set of receptors and, potentially, with different roles in infection and disease. This chapter provides strategies for identifying and analyzing host glycan receptors and the bacterial adhesins that exploit them as receptors, with particular reference to adherence of the gastric pathogen Helicobacter pylori.
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7. |
- Aspholm, Marina, et al.
(author)
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SabA is the H. pylori hemagglutinin and is polymorphic in binding to sialylated glycans.
- 2006
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In: PLoS pathogens. - : Public Library of Science (PLoS). - 1553-7374 .- 1553-7366. ; 2:10
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Journal article (peer-reviewed)abstract
- Adherence of Helicobacter pylori to inflamed gastric mucosa is dependent on the sialic acid-binding adhesin (SabA) and cognate sialylated/fucosylated glycans on the host cell surface. By in situ hybridization, H. pylori bacteria were observed in close association with erythrocytes in capillaries and post-capillary venules of the lamina propria of gastric mucosa in both infected humans and Rhesus monkeys. In vivo adherence of H. pylori to erythrocytes may require molecular mechanisms similar to the sialic acid-dependent in vitro agglutination of erythrocytes (i.e., sialic acid-dependent hemagglutination). In this context, the SabA adhesin was identified as the sialic acid-dependent hemagglutinin based on sialidase-sensitive hemagglutination, binding assays with sialylated glycoconjugates, and analysis of a series of isogenic sabA deletion mutants. The topographic presentation of binding sites for SabA on the erythrocyte membrane was mapped to gangliosides with extended core chains. However, receptor mapping revealed that the NeuAcalpha2-3Gal-disaccharide constitutes the minimal sialylated binding epitope required for SabA binding. Furthermore, clinical isolates demonstrated polymorphism in sialyl binding and complementation analysis of sabA mutants demonstrated that polymorphism in sialyl binding is an inherent property of the SabA protein itself. Gastric inflammation is associated with periodic changes in the composition of mucosal sialylation patterns. We suggest that dynamic adaptation in sialyl-binding properties during persistent infection specializes H. pylori both for individual variation in mucosal glycosylation and tropism for local areas of inflamed and/or dysplastic tissue.
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8. |
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9. |
- Bugaytsova, Jeanna, et al.
(author)
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pH regulated H. pylori adherence : implications for persistent infection and disease
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Other publication (other academic/artistic)abstract
- Helicobacter pylori’s BabA adhesin binds strongly to gastric mucosal ABH/Leb glycans on the stomach epithelium and overlying mucus, materials continuously shed into the acidic gastric lumen. Here we report that this binding is acid labile, acid inactivation is fully reversible; and acid lability profiles vary with BabA sequence and correlate with disease patterns. Isogenic H. pylori strains from the gastric antrum and more acidic corpus were identified that differed in acid lability of receptor binding and in sequence near BabA’s carbohydrate binding domain. We propose that reversible acid inactivation of receptor binding helps H. pylori avoid clearance by mucosal shedding, and that strain differences in acid lability affect tissue tropism and the spectrum of associated gastric diseases.
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10. |
- Bullington, Jennifer, et al.
(author)
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Meaning out of chaos : a way to understand chronic pain
- 2003
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In: Scandinavian Journal of Caring Sciences. - : Wiley. - 0283-9318 .- 1471-6712. ; 17:4, s. 325-331
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Journal article (peer-reviewed)abstract
- Pain is a multidimensional phenomenon lying at the intersection between biology and culture. The modern understanding of pain takes into account emotional, psychological, socio-political and existential aspects of pain as well as physiological, anatomical factors. Our aim in this study was to deepen the understanding of psychosocial, existential aspects of pain and to discuss how clinicians can better understand and treat patients with chronic pain. A focus group was formed consisting of a researcher and a group of clinicians (n = 3) with various backgrounds working at a specialized pain clinic. The group met once a month during a 6-month period. Questions concerning the life-world of the pain patient as well as inquiries into the conditions for 'the good clinical encounter' were investigated. The results of this study consist of a systematization of the data (focus group meetings) collected and analysed in a collaborative effort between the researcher and group participants. The findings are presented in terms of themes. The main metaphor used to describe the path from the seeking of medical help to successful rehabilitation was order out of chaos. Ordering chaos was a process moving from diagnosis through a phase of heightened self-awareness towards responsibility-taking on the part of the patient. Related themes presented, illustrated and discussed in the paper concern problems of linkage, the role of flexibility and creativity in the healing process and the kind of clinical encounter conducive for the journey from chaos to the creation of new meaning.
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11. |
- Gustafsson, A., et al.
(author)
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Carbohydrate-dependent inhibition of Helicobacter pylori colonization using porcine milk
- 2006
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In: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 16:1, s. 1-10
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Journal article (peer-reviewed)abstract
- Breast milk has a well-known anti-microbial effect, which is in part due to the many different carbohydrate structures expressed. This renders it a position as a potential therapeutic for treatment of infection by different pathogens, thus avoiding the drawbacks of many antibiotics. In a previous study, we showed that pigs express the Helicobacter pylori receptors, sialyl Lewis x (Le x) and Le b, on various milk proteins. Here, we investigate the pig breed- and individual-specific expression of these epitopes, as well as the inhibitory capacity of porcine milk on H. pylori binding and colonization. Milk proteins from three different pig breeds were analysed by western blotting using antibodies with known carbohydrate specificity. An adhesion assay was used to investigate the capacity of pig milk to inhibit H. pylori binding to neoglycoproteins carrying Le b and sialyl-di-Le x. alpha1,3/4-fucosyltransferase transgenic FVB/N mice, known to express Le b and sialyl Le x in their gastric epithelium, were colonized by H. pylori and were subsequently treated with Le b- and sialyl Le x-expressing or nonexpressing porcine milk, or water (control) only. The degree of H. pylori colonization in the different treatment groups was quantified. The expression of the Le b and sialyl Le x carbohydrate epitopes on pig milk proteins was breed- and individual specific and correlated to the ability of porcine milk to inhibit H. pylori adhesion in vitro and H. pylori colonization in vivo. Milk from certain pig breeds may have a therapeutic and/or prophylactic effect on H. pylori infection.
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13. |
- Remberger, Mikael, et al.
(author)
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Screening of Emerging Brominated Flame Retardants (BFRs) and Polybrominated dibenzofurans (PBDFs)
- 2014
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Reports (other academic/artistic)abstract
- As an assignment from the Swedish Environmental Protection Agency, a screening study of selected emerging brominated flame retardants (BFRs) and polybrominated dibenzofurans (PBDFs) has been carried out. Additional substances in the screening were polybrominated diphenyl ethers (PBDEs), polybrominated dibenzodioxins (PBDDs) and chlorinated dioxins and furans (PCDDs and PCDFs).The overall objective of this screening study was to determine the concentrations of selected BFRs and PBDFs in a variety of media in the Swedish environment. Additional aims were to assess possible emission sources and to highlight important transport pathways in the environment including large scale transport. An issue for the screening was also to investigate the presences of the BFRs in biota to give an indication if they pose an environmental risk. Possible human exposure was investigated by analysing BFRs in human blood samples and PBDFs in human milk samples.Measurements have been carried out both at background- and urban sites. The sampling was mainly performed at the Swedish west coast with Göteborg representing the urban area. Sediment and biota was sampled in the estuary of Göta Älv and in a background area.For identification of pathways to the environment storm water/sludge and samples from WWTPs were collected. Dust samples from different indoor environments were taken both at public spaces and in homes. Air and dust samples were collected at a recycling industry for electronic waste. Fire extinguishing water from a fire at a recycling industry was included in the sampling program.The emerging BFRs, PBDEs and PBDFs occurred in "high" concentrations in air and dust from the recycling industry. The occurrence of BFRs at this electronic waste facility shows that electronic articles contain these chemicals. BDE-209 and DBDPE were found in highest concentrations. DBDPE has similar applications as BDE-209 and it has been marketed as a general substitute for this chemical. The occurrence of PBDFs may indicate that the BFRs are contaminated or that PBDEs are transformed to PBDFs in the recycling processes.The presence of both the emerging BFRs and PBDEs in dust collected in a "new private car" shows that theses flame retardants are used in textiles and plastic details in newly manufactured cars. DBDPE and BDE-209 which are used as flame retardants in textiles occurred in high concentration. The simultaneous occurrence of high levels of PBDFs indicates presence in BFR formulations.The occurrences of the included BFRs in dust from different indoor environments indicates a wide application of these chemicals in articles and household products and that diffuse emissions of BFRs from consumer products may take place in the indoor environment. The differences in the distribution among the BFRs for the different dust samples indicate that tHigher ratios of PBDFs vs. BDE-209 were found in dust from environments that are likely to contain BFR containing plastics (offices and recycling facilities) than in dust from environments containing BFR treated textile products (car and conference center interiors). This may indicate that PBDFs are formed during production or use of flame retarded plastics.The emissions of BFRs and PBDFs will take place both to air and water. BFRs and PBDFs emitted indoors to air and to settled dust may via ventilation be transported to outdoor air. The presence of these pollutants in influent, effluent and sludge from municipal WWTPs also indicate that diffusive emissions from household products occur and that these chemicals may be emitted to the environment from WWTPs. The occurrence of the BFRs and PBDD/Fs in storm water and fire extinguishing water shows that this may also be pathways to the environment.Thus, the emerging BFRs and PBDFs were generally found in samples from WWTPs, storm water, indoor air and dust, indicating that they may be emitted and transported to the environment via these sources and pathways.Several of the emerging BFRs occurred in all the included environmental matrices except in atmospheric deposition. The concentrations in samples at urban sites were higher compared to background samples.Most of the emerging BFRs were detected in urban air, in the same levels or somewhat lower than BDE-47, -100 and -99. BDE-209 occurred in the highest concentrations. One of the emerging BFRs, HBB, was detected in background air, in the same concentration range as the PBDEs. It was found both at the Swedish West coast and in the remote area in Northern Finland, which shows the potential for atmospheric long range transport for HBB.PBDD/Fs were found in all air and deposition samples. There appears to be an annual variation in both PBDD/F and PCDD/F concentrations, with higher levels during winter. Significantly elevated levels were detected in May-June 2011, which coincided with extensive forest fires in southern Russia and Ukraine.In sediments, the emerging BFRs were only detected in a sample from Göta Älv near a former industrial site where they occurred in the same concentration level as the penta-BDEs.The occurrence of emerging BFRs in biota from background sites shows that these chemicals like the PBDEs are further spread to the ecosystem. The distribution of the BFRs differed between the various species as well as among the different sampling sites.The only emerging BFR detected in human sera was PBEB, which occurred in one out of 15 samples. PCDD/Fs were found in all human milk samples, but no PBDD/Fs were detected.
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14. |
- Rhen, Christofer, et al.
(author)
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Effects of raw material moisture content, densification pressure and temperature on some properties of Norway spruce pellets
- 2005
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In: FUEL PROCESSING TECHNOLOGY. - : Elsevier BV. - 0378-3820. ; 87:1, s. 11-16
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Journal article (peer-reviewed)abstract
- In order to study the pelletising process, Norway spruce sawdust pellets were produced under strictly controlled conditions on a laboratory scale. The aim of the work was to investigate how the moisture content of raw material and the densification parameters, pressure and temperature, affect compression strength, dry density and moisture uptake of the formed pellets. In the experiments performed, temperature (26–144 °C), moisture content (6.3–14.7 wt.% of d.b.) and pressure (46–114 MPa) were the factors which varied according to a prescribed central composite design. The relationships between the factor settings and the responses (dry density, moisture uptake and compression strength) were evaluated by multiple linear regressions.In the present study, it was found that high compression strength was strongly correlated with the density of the pellets. High temperature (at least up to 144 °C) and low moisture content at the start of compression (down to 6.3 wt.% of d.b.) increased the dry density of the pellets. Remarkably, compression force had very little effect in the tested range of 46–114 MPa, indicating that pressure in the die does not need to be higher than 50 MPa.Similarly, compression force had very little effect on moisture uptake in the pellets. The least moisture uptake occurred when the pellets were produced at 90 °C.
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15. |
- Sjöström, Mårten, 1967-, et al.
(author)
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A digital 3D signage system and its effect on customer behavior
- 2011
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In: The International Conference on 3D Imaging (IC3D). - : IEEE conference proceedings. - 9781479915774
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Conference paper (peer-reviewed)abstract
- The use of digital signs simplifies distribution. Importantly, it draws more attention than static signs. A way to increase attention is to add an experienced depth. The paper discusses possible alternatives for extending an existing digital signage system to display stereoscopic 3D contents, comparing a decentralized distribution solution and a centralized solution. A functional prototype system was implemented. A new 3D player was developed to render views from different formats. The implemented system was used to study customer behavior when exposed to digital stereoscopic 3D signage in a direct sales situation. The proportion of sales of selected products related to the total number of sold products varied approximately equally before and during tests. An interview study suggests that the sign did not interact with customer decisions: customers were lost at different stages in this series of steps, among others the sign placement.
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16. |
- Sjöström, Rolf
(author)
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Absence of effect of para-chlorophenylalanine on 5-hydroxyindoleacetic acid in cerebrospinal fluid in man
- 1972
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In: Psychopharmacologia. - 0033-3158. ; 27:4, s. 393-396
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Journal article (peer-reviewed)abstract
- The effect of para-chlorophenylalanine (PCPA) on the 5-hydroxy-indoleacetic acid (5-HIAA) content in human cerebrospinal fluid (CSF) has been studied. There was no effect on the CSF-content of 5-HIAA 12, 24 or 48 h after a single dose of PCPA 1 g p.o. Neither was there any effect after 1 g/day during 4 days. The increase of 5-HIAA after administration of probenecid was reduced during treatment with PCPA 1 g/day. This reduction, however, is not due to a diminished production of 5-HIAA by PCPA but probably caused by a pharmacological interaction between probenecid and PCPA since the concentrations of probenecid in CSF were lower during administration of PCPA than without that drug.It is concluded that PCPA in the doses used in this study gives no effects on the CSF-concentrations of 5-HIAA.
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18. |
- Sjöström, Rolf, 1928-
(author)
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Forskningsarkivet tur och retur
- 2003
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In: Arkiven i forskningens tjänst. - Umeå : Umeå universitet, Forskningsarkivet. ; , s. 80-88
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Book chapter (other academic/artistic)
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19. |
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20. |
- Xu, Hong-Tao, et al.
(author)
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Effects of fucosylated milk of goat and mouse on Helicobacter pylori binding to Lewis b antigen
- 2004
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In: World Journal of Gastroenterology. - Beijing : WJG Press. - 1007-9327 .- 2219-2840. ; 10:14, s. 2063-2066
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Journal article (peer-reviewed)abstract
- Aim:To evaluate the effects of animal milk containing fucosylated antigens on Helicobacter pylori (H pylon) binding to Lewis b antigen. Methods:A mammary gland expression vector containing human α1-3/4-fucosyltransferase cDNA sequences was constructed. Transient expression of human(α1-3/4-fucosyltransferase cDNA in goat mammary cell and establishment of transgenic mice were performed. The adhesion inhibitory properties of milk samples were analyzed by using Hpylori. Results: Goat milk samples were found to inhibit bacterial binding to Lewis b antigen. The highest inhibition was observed 42 h after injection of the plasmid. The binding activity of Hpylori to Lewis b antigen reduced mostly, by 83%, however milk samples from transgenic mice did not inhibit Hpylori binding to Lewis b antigen. Conclusion: The use of “humanized“ animal milk produced by the transgenic introduction of fucosylated antigen can perhaps provide an alternative therapy and preventive measure for Hpylori infection.
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21. |
- Åberg, Anna, et al.
(author)
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Helicobacter pylori adapts to chronic infection and gastric disease via ph-responsive baba-mediated adherence
- 2017
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In: Cell Host and Microbe. - : Elsevier BV. - 1931-3128 .- 1934-6069. ; 21:3, s. 376-389
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Journal article (peer-reviewed)abstract
- The BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease.
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