| 1. |
- Johansson, A. Malin
(författare)
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Remote sensing of supra-glacial lakes on the west Greenland Ice Sheet
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Greenland Ice Sheet is the largest ice sheet in the northern hemisphere. Ongoing melting of the ice sheet, resulting in increased mass loss relative to the longer term trend, has raised concerns about the stability of the ice sheet. Melt water generated at the surface is temporarily stored in supra-glacial lakes on the ice sheet. Connections between melt water generation, storage and ice sheet dynamics highlight the importance of the surface hydrological system.In this thesis different methods are used that improve our ability to observe the supra-glacial lake system on the west Greenland Ice Sheet. This region of the Greenland Ice Sheet has the most extensive supra-glacial hydrological system with a dense network of streams connecting lakes that can exceed several square kilometres in area. Synthetic Aperture Radar (SAR) and visible-near infrared (VNIR) images are used to explore the potential of different sensor systems for regular observations of the supra-glacial lakes. SAR imagery is found to be a useful complement to VNIR data. VNIR data from moderate resolution sensors are preferred as these provide high temporal resolution data, ameliorating problems with cloud cover.The dynamic nature of the lakes makes automated classification difficult and manual mapping has been widely used. Here a new method is proposed that improves on existing methods by automating the identification and classification of lakes, and by introducing a flexible system that can capture the full range of lake forms. Applying our new method we are better able to analyse the evolution of lakes over a number of melt seasons. We find that lakes initiate after approximately 40 positive degree days. Most lakes exist for less than 20 days before draining, or later in the season, and less often, freezing over. Using the automated method developed in this thesis lakes have been mapped in imagery from 2001–2010 at approximately five day intervals.
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| 2. |
- Johansson, Yvonne A., 1956-
(författare)
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Delirium hos äldre patienter som vårdas på sjukhus : identifiering av symtom, tecken och riskfaktorer samt journalförda vårdåtgärder
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- I samband med sjukhusvård kan äldre patienter riskera försämrad hälsa, inklusive delirium. Delirium, som är vanligt hos äldre patienter på sjukhus, är ett akut och allvarligt tillstånd med svåra konsekvenser för såväl patienten som för närstående, vårdpersonal och hälso- och sjukvård. Det är viktigt att delirium förebyggs, identifieras och behandlas. Forskning visar dock på brister i vården, vilket kan påverka patienternas hälsa och välbefinnande negativt. Det övergripande syftet med avhandlingen var att identifiera och beskriva symtom, tecken, riskfaktorer och vårdåtgärder vid delirium hos äldre patienter som vårdas på sjukhus samt att utvärdera tillämpbarheten av ett bedömningsinstrument för att identifiera delirium. Alla deltagande patienter var 65 år och äldre och rekryterades från ett länssjukhus (I-IV) och ett universitetssjukhus (III, IV). Dessutom ingick de bedömare som bedömt delirium med bedömningsinstrumentet 4AT i delarbete IV. Delarbetena bestod av en kvantitativ subgruppsanalys (n=25) av en punktprevalensstudie (n=210), en retrospektiv journalgranskning (n=78) med kvalitativ analys och två tvärsnittsstudier baserade på samma urval (n=200) med kvantitativa (III, IV) och kvalitativa analyser (IV). Data samlades in genom strukturerade intervjuer, validerade instrument, patientjournaler, frågeformulär och en öppen intervjufråga.Patienterna rapporterade svåra och besvärande symtom vilka hade journalförts i begränsad omfattning (14%). Även kognitiv funktionsnedsättning och patienternas beskrivningar av sitt välbefinnande hade journalförts i liten utsträckning. Patienternas tecken på delirium ledde till nedsatt förmåga att såväl delta i sin egen vård som att undvika skada. Vårdpersonalen svarade delvis på patienternas tecken på delirium då åtgärderna kunde vara både anpassade, bristfälliga och utöver vanlig vård. Skörhet var den starkaste riskfaktorn för delirium. Andelen patienter med delirium ökade med svårighetsgraden av skörhet. Den svenska versionen av bedömningsinstrumentet 4AT för att identifiera delirium hade diagnostisk precision och klinisk användbarhet med hög interbedömarreliabilitet. Bedömningsinstrumentet 4AT tolererades väl av patienterna, var lätt att använda och tog några minuter att genomföra. Detta innebär att det nu finns ett enkelt bedömningsinstrument för delirium på svenska som kan användas för att bedöma delirium hos äldre patienter som vårdas på sjukhus.Endast en mindre del av den studerade vården kan ses som personcentrerad och patientsäker. Struktur, systematik och ett helhetsperspektiv tycktes saknas, liksom ett personcentrerat förhållnings- och arbetssätt. För att minska incidensen av delirium, lidande och kostnader behöver vården förbättras. Det finns behov av att öka kunskapen om delirium och att se delirium som en vårdskada inom all vård. Vidare finns behov av att utveckla vården genom att tydligt integrera ett personcentrerat och patientsäkert förhållnings- och arbetssätt för att nå en helhetssyn på patienten. Målet är att främja hälsa och välbefinnande genom att förebygga delirium. För att möjliggöra identifiering av individuella vårdbehov är det en förutsättning att etablera en tillitsfull vårdrelation med den äldre patienten, där patientens perspektiv tillvaratas. Individuella vårdbehov behöver identifieras strukturerat och systematiskt genom bedömning med bedömningsinstrument av symtom, tecken, välbefinnande, delirium och riskfaktorer för delirium innefattande skörhet samt kognitiv funktionsnedsättning. Detta möjliggör individuellt anpassade vårdåtgärder.Ett individuellt anpassat omhändertagande som överensstämmer med ett integrerat personcentrerat och patientsäkert förhållnings- och arbetssätt skulle kunna bidra till att minska incidensen av delirium vilket kan skapa positiva effekter för såväl patienter som för vårdpersonal och hälso- och sjukvård.
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| 3. |
- Khosravi, Sara, 1978-
(författare)
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Protein-Based Adhesives for Particleboards
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this study was to elucidate the possibilities to use wheat gluten (WG) as a binder for particleboards, as well as soy protein isolate (SPI). The focus was on the effect of the adhesive formulation and the processing conditions, while the press parameters were kept constant. Some aspects of the dispersion and the preparation of the dispersions that were investigated are: the dispersing agent (sodium hydroxide 0.1 M or citric acid 0.05 M), the time (1, 3 or 5h) to prepare the dispersion, the temperature (room temperature, 50 or 80°C) during the preparation of the dispersions and the effect of storing (1, 2.5 or 4 days) the dispersions before application. Additionally, utilization of cross-linker polyamidoamine-epichlorohydrin (PAAE) and trimethylolpropane triacetoacetate (AATMP) were evaluated. Furthermore, the utilization of green particles versus dried particles was examined. The concentration (12, 16, 20 or 24%) of WG dispersion and the process for applying it to the particles were studied. Two application methods were evaluated, in application method 1 (appl. 1) all the dispersion was added to the particles in one step before the particles were dried. When application method 2 (appl. 2) was employed the dispersion was added in two steps, some of the dispersion was added before the drying and some after the drying. The considered board properties were internal bond (IB), thickness swelling (TS) and water absorption (ABS). The wetting, penetration and film formation of the WG dispersions on the wood was investigated employing different microscopy techniques. For the WG dispersions it looks as if a lower temperature is preferable for the preparation of the dispersion and that the time to prepare the dispersion is of no importance. Furthermore, storing the dispersions for more than one day before it was used as an adhesive for particleboards (PB) resulted in poorer boards. Using the right cross-linker, such as PAAE enhances the binding abilities of WG. According to this study it is beneficial to use dried particles instead of green particles. Additionally, the results show that the interaction between the concentration of WG dispersion and how it is applied is a significant factor, considering the IB value. However, in general the two step process (appl. 2) is preferable. The microscopy study reveals that this can be explained by the balance between wetting, penetration, and flow of the dispersion on the wood. The two step application results in less over-penetration when the viscosity of the dispersion is low.
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| 4. |
- Bettelli, Mercedes A., 1992-
(författare)
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Bio-based and Biodegradable Foams from Wheat Gluten using Up-Scalable Processes
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, the production of bio-based and biodegradable foams from wheat proteins (wheat gluten) is presented. Wheat gluten, a side stream from the ethanol/starch industry, was processed using both batch and continuous foaming methods. To produce the foams, glycerol, an effective protein plasticiser, was used, with two foaming agents common in food: sodium bicarbonate (SBC) and ammonium bicarbonate (ABC), to generate soft foams with both closed-and open-cell structures. ABC proved to be a better foaming agent in foam extrusion than SBC, but SBC performed well in the batch methods. Due to ABC’s low decomposition temperature, extrusion could take place at a temperature as low as 70 °C. Three different multifunctional additives (citric acid, gallic acid and genipin) were also used to influence and improve the foam properties. The mechanical properties showed that some of the materials could be potentially useful in cushioning and sealing applications. The foams also showed a high absorption of saline (model substance for body fluid) and blood (in the form of sheep’s blood), even under mechanical pressure. Based on these results, a wheat gluten-based product was manufactured as a proof-of-concept. The degradability of the foam in various relevant environments was studied. It was found that some foams degraded almost completely in soil after 8 weeks and in alkaline water after 5 weeks. It was also demonstrated that the foam also worked as a good fertilizer. As an alternative to direct composting when the foam is no longer used, the possibility of reusing the foam in a different form was evaluated. In this context, it was possible to produce plastic films from the foam.
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| 5. |
- Brundin, Peik M. A., 1975-
(författare)
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Sex differences in immune response and sex hormone receptor expression in healthy individuals and during viral infection
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is sex-bias in morbidity and mortality from infectious diseases. Infections kill more men than women and several studies have pointed out differences in the immune system as a reason. The sex hormones estrogen, progesterone and testosterone all shape the effect of the immune response on multiple levels. Women at fertile age have been suggested to have higher proinflammatory responses from inflammatory stimuli compared to men and post-menopausal women, which has been ascribed to their higher estrogen levels. This could possibly lead to a more active pathogen response but may also result in a detrimental immunopathology to infections or development of autoimmune reaction.The overall aim of this thesis is to study the contribution of sex hormones and sex hormone receptors (SHR) to sex differences in immune response. We focus on peripheral blood mononuclear cells (PBMCs) to study such relationships in healthy individuals, as well as in individuals with asymptomatic Torque Teno Virus infection, and individuals with acute Puumala virus infection.In Paper I, we investigated expression of SHR and immune response genes in PBMC from healthy premenopausal (pre-MP) women during the menstrual cycle. The expression levels were estimated using a qPCR Array (Taqman low-density array, TLDA). SHR expression did not change significantly during the menstrual cycle, but several key immune regulatory genes were significantly more expressed during the ovulatory and mid luteal phase. Further, we separated PBMC into cell subsets (CD4+ T-cells, CD8+ T-cells, CD56+ NK-cells, CD14+ monocytes and CD19+ B-cells) and analyzed the expression through qPCR of estrogen receptors (ERs), ERα, ERβ1 (wildtype) and the isoform ERβ2. For the first time and unexpectedly, we demonstrate that the isoform ERβ2 was more abundant than wildtype ERβ1. The data from this paper provides new knowledge on the contribution of the menstrual cycle on immune response.In Paper II, we explored the use of Torque Teno Virus as a secondary functional immune marker in men and women. Expression of viral TTV DNA in PBMCs was estimated using a qPCR kit from Argene (R-gene) and analyzed in relation to serum sex hormone levels. The results showed that 50% of the men, 25% the post-MP women, and 18% of the pre-MP women were TTV+. Interestingly, all pre-MP women that were TTV+ had hormonal aberrances and were either anovulatory and/or hypothyroid. TTV+ pre-MP women also had significantly lower progesterone levels than TTV- pre-MP women. This paper indicates that the prevalence of TTV in PBMC differs between men, pre-MP and post-MP women. Furthermore, hormonal aberrances (at least in pre-MP women) will lead to increased prevalence of TTV.In Paper III we investigated the expression of ERα, ERβ1 and ERβ2 in PBMC from patients with Nephropathia epidemica, the viral zoonotic disease caused by Puumala virus, a Hanta virus known to affect more men than women. Expression of ERs in PBMCs and clinical laboratory results during the acute and convalescent phases were analyzed using a principal component analysis (PCA). The results show differences in ER expression and support previous findings that men and women have a different clinical pictureIn conclusion, the results in this thesis reveal distinct patterns of immune response related to sex hormone levels, SHR expression and the phases of the menstrual cycle supporting that there a link between sex hormone levels and immune responses. Further, we show that the ER isoform ERβ2 is more abundant in PBMCs than what was previously described. The data in this thesis adds to the knowledge to the sex differences in immune response and exemplifies the importance of taking these differences into account in the clinic.
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| 6. |
- Johansson, Adam Johannes, 1976-
(författare)
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Biomimetic Transition Metal Catalysts : Insights from Theoretical Modeling
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The scientific interest in the chemistry of synthetic transition metal complexes is motivated by at least two arguments:1.These can be regarded as models of biological transition metal complexes, e.g. metalloenzymes, whose functions can be difficult to reveal in detail due to their complexity.2.Transition metal complexes are used for catalytic purposes in the industrial synthesis of chemicals. There is a large potential for further development of this technology, which can be motivated both by economic and environmental arguments.In the present thesis, density functional theory (a quantum mechanical method) has been applied to model reactions involving synthetic iron and copper complexes in solution. The complexity of the solvent environment is a challenging problem for theoretical investigations and a significant part of the theses has been to investigate the mechanistic effects of metal-coordinating solvent molecules, Lewis bases and counter ions. For example, it is explained why the cleavage of the O-O bond in heme-diiron-peroxides is faster in the presence of a coordinating Lewis base. Furthermore, the experimentally observed structure-activity relationship between the Fe(III)(µ-O)2Fe(IV) and (H2O)Fe(III)(µ-O)Fe(IV)O motifs is given an explanation. In addition, the present thesis presents a systematic investigation of how the self-interaction error in density functional theory (DFT) affects the modeling of transition metal catalysis.
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| 7. |
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| 8. |
- Johansson, Henrik A. B., 1979-
(författare)
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Ionization and Fragmentation of Complex Molecules and Clusters : Biomolecules and Polycyclic Aromatic Hydrocarbons
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This work deals with ionization and fragmentation of biomolecules and polycyclic aromatic hydrocarbon (PAH) molecules. They are studied in the gas phase both as isolated molecules and as weakly bound clusters. The purpose of the experimental and theoretical investigations are to elucidate charge and energy transfer and related redistribution processes, as well as fragmentation behaviors. The first part of this thesis presents results from studies on biomolecular ions, in particular nucleotides and peptides, which are primarily examined in electron capture induced dissociation processes. These investigations are relevant for the better understanding of radiation damage to DNA and processes involved in the sequencing of proteins. It is found that the immediate environment have a decisive influence on the fragmentation behaviors. Evaporation of surrounding molecules protect the biomolecules, but their effect on the electronic structure may also enhance or suppress different fragmentation channels. In the second part of the thesis, results from studies on PAH molecules are presented. Experimentally, their properties are mainly probed through collisions with atomic ion projectiles having kilo-electronvolt kinetic energies. As a widespread pollutant on Earth, and as a family of abundant molecules in space, PAHs are not only relevant from an environmental and health perspective, but they are also important for the understanding of the universe. The present results relate to the stabilities of these molecules, both in isolated form and in clusters, when heated or multiply ionized. It is found to be easier to remove several electrons from clusters of PAH molecules than from isolated PAHs, and fission processes determine their ultimate stabilities. Heated low-charge state clusters of PAHs undergo long evaporation sequences once these have started. For isolated and heated PAHs, internal structural rearrangements are demonstrated to be important in the fragmentation processes.
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| 9. |
- Johansson, Karin
(författare)
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Raising the Costs or Lowering the Bar : International influences on conflict-related sexual violence
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation contributes to the growing literature on conflict-related sexual violence (CRSV). More specifically, the four essays it contains advance our understanding of CRSV by shedding light on the intersection between international involvement and CRSV perpetrated by states and rebel groups engaged in civil war. Despite the increased attention to CRSV among international policy-makers, this intersection has been examined only sparsely within the scholarship on CRSV. Essays I, II, and III address the overarching question of how different types of international involvement influence the level of CRSV. Essay I offers a global study of the effect of third-party military involvement on levels of CRSV. It argues that shifts in the balance of power following external involvement tend to aggravate the situation with regard to CRSV, and it finds indicative support for this. Essay II examines the capacity of peacekeeping missions to mitigate CRSV. It finds that the effectiveness of peacekeeping hinges on the degree of internal control exercised by states and rebel groups. Essay III looks beyond military involvement and focuses on the political power of condemnation. Using newly collected data on condemnations of sexual violence issued by the United Nations (UN) human-rights body between 1987 and 2014, the study tests the extent to which governments that perpetrate CRSV can be influenced by international condemnation. In parallel, the study examines the power of domestic outrage expressed through protests. The findings have important policy implications: Domestic protests are associated with an escalation of CRSV by states. International condemnation correlates with declines in CRSV in recent years (2008–2014), but not historically. International involvement – whether multilateral or unilateral – only materialises if fellow states so decide. Essay IV thus focuses on the willingness of states to take action against CRSV perpetrated by other states. By examining bilateral condemnations of sexual violence issued within the UN Universal Periodic Review, this essay sheds light on the diplomatic relationships and political interests that shape the (un)willingness of individual states to condemn CRSV. In sum, this dissertation makes both theoretical and empirical contributions to the research on CRSV, as well as to the scholarship on international involvement in civil wars more broadly.
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| 10. |
- Johansson, Maria A., 1981-
(författare)
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Infant gut microbiota, immune responses and allergic disease during childhood
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The early-life microbiota is important for postnatal immune maturation and implied in immune mediated diseases. The aim of this work was to study specific species of bacteria in the gut microbiota and relate them to immune function and allergic disease during childhood.In paper I we investigated gut bacteria in feces from infants included in a prospective allergy cohort. We found that children with non-allergic parents were more likely to be colonized with a group of lactobacilli. Further, lactobacilli colonization was more prevalent in children remaining non-allergic, regardless of allergic heredity. In paper II we related the infant gut bacteria to immune function at two years of age. Infant Staphylococcus (S.) aureus colonization associated with increased immune responsiveness, whereas co-colonization with S. aureus and lactobacilli associated with reduced responses. In paper III we investigated T regulatory (Treg) cell phenotype and cytokine production during childhood, and related S. aureus and lactobacilli colonization to Treg phenotype at the age of two. The Treg population matured with age, regarding phenotype and cytokine production. Furthermore, infant S. aureus colonization associated with Treg phenotype at the age of two. In paper IV we investigated the in vitro peripheral blood mononuclear cells responses to soluble factors produced by lactobacilli and S. aureus. Both T- and natural killer cells responded with cytokine production, degranulation and proliferation after S. aureus and simultaneous culture with lactobacilli could dampen the S. aureus-induced responses.Taken together this thesis shows that the gut microbiota is altered in children who develop allergies, and that early life bacteria associate with immune function. Our in vitro findings support that lactobacilli modulate immune maturation and responses, and that early lactobacilli-colonization may be important for a properly regulated maturation of the immune system.
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