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Sökning: WFRF:(Eriksson Leif Professor) > (2005-2009)

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1.
  • Quennerstedt, Mikael, 1966- (författare)
  • Att lära sig hälsa
  • 2006
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The aim of this dissertation is to contribute to an understanding of the subject content in Physical Education (PE) foremost from a health perspective. By using an approach deriving from John Dewey’s transactional perspective on meaningmaking (Bentley & Dewey 1949), and a discourse theoretical position, the discourses identified in the dissertation’s studies are consequently regarded as participants in pupils’ meaning-making. This makes it possible to discuss the results of the studies in terms of the institutional content and conditions of meaning-making in PE. The thesis consists of three different discourse analyses, where the institutionalised aspect of meaning-making in PE is examined by analysing local curriculum documents from 72 Swedish compulsory schools. The results of the dissertation show that in the study of subject content in PE a dominance of an activity discourse can be identified, although a social development discourse is also identified as being important in the documents. The results, thus, suggest that the subject content of PE can be characterised by a wide variety of activities, where pupils are expected to be active participants in the sense of being physically active. The content is also characterised by actions promoting good relationships, co-operation and consideration for others. Actions privileged within the discourses in PE are movement, physical activity, trying many different activities together, active participation, good relations and enjoyment. The results also show that health is explicitly constituted as fitness training, life-long physical activity and knowledge about physical training based on scientific facts from physiology and anatomy. Learning health in PE thus mainly consists of a pathogenic health discourse. But from a salutogenic perspective, health is also constituted as the possibility to participate in movement, physical leisure activities and social relations, and enjoy a life-long engagement in different movement and sport activities. The analysis also shows, however, that within the frame of the subject content of PE, it is also possible to regard health in terms of a commitment to health- and environmental issues, a sense of well-being in ongoing activities and an active involvement in subject content matters within PE. Health can therefore be constituted in different ways within PE, although this is not always made explicit in the local curriculum documents.
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2.
  • Ristilä, Mikael (författare)
  • Vitamin B6 as a potential antioxidant : a study emanating from UV-B-stressed plants
  • 2006
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Increased influx of solar UV-B radiation (280-320 nm), due to a decreasing stratospheric ozone layer, impacts severely on plants. Some of the UV-B effects on plants are related to stress induced by produced reactive oxygen species (ROS). Pyridoxine (vitamin B6) has been reported to be a potential quencher of ROS.Previous studies have shown that the PDX1.3 gene (encoding a key enzyme in vitamin B6 biosynthesis) is up-regulated by UV-B. We showed that this up-regulation also occurs at the protein level in UV-B exposed Col-0 wild-type plants. Studies performed using pdx1 knock-out mutants of Arabidopsis thaliana showed elevated transcripts levels for LHCB1*3 and PR-5 compared with the Col-0 wild-type. The pdx1 knock-out mutants showed an increased sensitivity towards H2O2-stress, but no increased sensitivity towards low dose UV-B-stress.To study the postulated role of pyridoxine as quencher of ROS in more detail, both theoretical and experimental studies were performed. Theoretical and experimental UV absorption spectra obtained at different protonation/deprotonation states of pyridoxine showed a very close resemblance at low and high pH. However, for the computational studies at physiological pH addition of counterions were required to accurately describe the experimental spectra.When theoretically studying the reactivity of pyridoxine towards three different ROS, .OH, .OOH and .O2-, the hydroxyl radical (.OH) was shown to be the most reactive species, while the superoxide radical (.O2-) showed no reactivity towards pyridoxine.In order to study the role of G-proteins in UV-B signal transduction pathways, UV-B irradiated G-protein mutants of Arabidopsis thaliana were studied. The regulation of the PDX1.3 gene was not affected in the G-protein mutants, regardless of the developmental stage of the plant. However, the expression of CHS was affected in the Ga subunit mutants.
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3.
  • Musa, Klefah Abrahem Klefah (författare)
  • Computational studies of photodynamic drugs, phototoxic reactions and drug design
  • 2009
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The most important criterion when designing new drugs or improving old ones in order to prevent side effects or at least diminish them is drug safety. Treatment of all diseases generally needs use of either topical application or systemic medications (transported in the blood) during a certain period of time. These treatments are associated with a number of adverse effects. Photosensitivity is one of those side effects, with phototoxicity as one of the photosensitivity disorders. This adverse side effect arises because of a reaction between UV or visible-light and the drug molecule, its active form or photoproduct(s). Due to phototoxic side effect, unexpected symptoms varying from just a simple rash to severe cutaneous affectations can appear. Furthermore, biomolecular damage occurs once the drug-light interaction takes place persistently and ends with cell death.Several drug families, such as over-the-counter drugs in the non-steroidal anti-inflammatory drug family of 2-arylpropionic acid derivatives, or prescription required fluoroquinolone drugs, have the capability to absorb mainly UV light radiation which in turn causes different phototoxic reactions by forming radical derivatives, reactive oxygen species or both. These may effect DNA, protein and lipid cell components leading to photogenotoxicity, photoallergy and lipid peroxidation, respectively. The photodegradation mechanisms of drugs belonging to the above mentioned families including ketoprofen, ibuprofen, flurbiprofen, naproxen, the active form of nabumetone, diclofenac and its main photoproduct, suprofen, tiaprofenic acid, naphazoline, norfloxacin and lomefloxacin are investigated in more detail in this thesis.The results obtained by computational density functional theory (DFT) and time-dependent-DFT (TD-DFT) are in line with experimental data available to date. The studies provide detailed insight into the molecular basis and understanding of the full photodegradation mechanisms of drugs mentioned above. This also plays an important role in preventing or at least reducing the phototoxic adverse effects by enabling the development of safe drugs in this area. Hence, new modified non-steroid anti-inflammatory molecules were designed by computational techniques. Obtained results suggest possibility of their future usage as pharmaceuticals with reduced photodegradation and cyclooxygenase 1 induced adverse side effects compared to the parent compounds.
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4.
  • Öhman, Marie, 1958- (författare)
  • Kropp och makt i rörelse
  • 2007
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Body and Power in MotionThis dissertation is concerned with body and politics, or, more specifi cally body, power and governance. The central question is how specifi c individuals and bodies are constituted in the teaching of Physical Education (PE) in school. Inspired by Foucault’s work and the research fi eld that emanates from the concept of governmentality, one of the ambitions is to develop a method that facilitates the study of power and governance processes in teachers’ and students’ interactive actions and dealings. With the aid of this approach, 15 video-recorded physical education lessons in 5 Swedish nine-year compulsory schools are analysed in order to demonstrate how governance processes are included in the work and activities in terms of how the processes of governance–self-governance are staged, and the direction this takes. In using the term direction I am here referring to the content the governance is aiming towards, where the question of which subjects and bodies are constituted is of substantial interest. This means that the study not only focuses on what is done, but also on the way in which it is done, i.e. it analyses both process and content.The results show that physical exertion and the desire for physical work is a thread that runs though the analysed material. It is mainly scientifi c knowledge about the body that is referred to in actual teaching practice. This is displayed through the use of a scientifi cally inspired language when talking about the body, where effects on muscles and degrees of oxygen intake are considered in connection with the physical activities. In connection with physical exertion, pupils are encouraged to do their best, try the activities on offer, cooperate with others and face challenges. In line with the governmentality perspective’s problematisation of the process governance–self-governance, the study highlights a governance mentality that is not characterised by coercion, but is rather directed towards different components of willingness where the students are expected to be participatory, take responsibility and govern their own actions in the direction of that which is most desirable and reasonable. The willingness component appears as the actual hub of character-building, were the students ought to be physically active, should want to do their best, be willing to try, should want to show solidarity and should want to defeat the others. The process of governance–self-governance is staged as different ways of appealing to one’s willingness in the activities studied. Specifi c governance techniques are used to support and promote self-governance work, i.e. different forms of encouragement strengthen the correct action, emphasising physical exertion as pleasurable and focuses on the fact that we are all involved in a common project. In the dissertation it is shown how the body is included in a socio-political context. Through the body the individual is turned into a participant of physical projects concerned with becoming a certain kind of social citizen. The body thus symbolises the complex encounter between the individual and society. In this way the study demonstrates and highlights tendencies that are evident in modern society. It is thus a narrative that indicates how we all become part of a discourse system.
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5.
  • Jansson, Emil, 1980- (författare)
  • Electronic characterization of molecules with application to organic light emitting diodes
  • 2007
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The presented thesis is devoted to the field of organic light emittingdiodes (OLEDs). Time-dependent Kohn-Sham density functional theory(TDDFT) is applied in order to eludicate optical properties such as fluorescence andphosphorescence for some of the most important materials. The accuracy of TDDFTis evaluated with respect to the calculated absorption and emission spectra forcommonly used light emitting polymers. A continuation of this work is devoted toPolyfluorene as this polymer has proven to be very promising. In this study thechain length dependence of its singlet and triplet excited states is analyzed as wellas the excited state structures.Understanding the phosphorescence mechanism of tris(2-phenylpyridine)Iridium isof importance in order to interpret the high efficiency of OLEDscontaining these specimens. The mechanism is analyzed by calculatingthe electric transition dipole moments by means of TDDFT usingquadratic response functions. As not only the optical properties are essential foreffective devices, electron transfer properties are addressed. The electrontransfer capability of the sulfur and nitrogen analogues of Oxadiazoleis evaluated through their internal reorganization energy.
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6.
  • Nash, Peppi, 1969- (författare)
  • Experimental and Clinical Studies of Oxidative Stress in Pre-Eclampsia
  • 2007
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Impaired placentation and oxidative stress are proposed to play major roles in the pathogenesis of pre-eclampsia (PE). It has recently been pointed out that PE might be more than one disease and may have several different pathogeneses. This thesis describes a new animal model for PE and examines the role of oxidative stress in early respective late onset PE.The effects of Suramin injections on day 10 and 11 of pregnancy were investigated in normal and diabetic rats of two strains (U and H), with or without additional vitamin E treatment. Suramin caused placental dysfunction in both rat strains: foetal growth restriction, increased resorption rate, reduced placental blood flow, and decreased maternal blood volume in the placenta. In the U strain Suramin also caused maternal hypertension and reduced renal blood flow. Oxidative stress in the Suramin treated rats was indicated by increased levels of isoprostane 8-iso-PGF2α in the placenta. Antioxidative treatment with vitamin E partly protected against the effects of Suramin. Streptozotocin-induced diabetes seemed to cause similar placental effects as Suramin, and in the diabetic rats the additional effects of Suramin were only moderate. In conclusion, Suramin-injected pregnant rats constitute a valid animal model for placental dysfunction (U and H rats) and PE (U rats).Oxidative stress was estimated in women with early onset (≤ 32 weeks) or late onset (≥ 35 weeks) PE, in normotensive pregnant women of respective gestational length, and in healthy non-pregnant women. The ratio of PAI-1/PAI-2 was measured in serum, and the amount of isoprostane 8-iso-PGF2α was measured in placenta, serum, and urine. The ratio of PAI-1/PAI-2 and placental isoprostane levels were higher in women with early onset PE compared with all other groups. Serum levels of isoprostane were similar between groups. Urinary levels of isoprostane were similar in all pregnant women, but lower in non-pregnant women. These data indicate that pregnancy increases general oxidative stress, and that early onset, but not late onset PE, causes increased oxidative stress also in placental tissue. The pathogeneses of early and late onset PE are, therefore, not likely to be identical.
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7.
  • Näslund Eriksson, Lisa, 1972- (författare)
  • Forest-Fuel Systems : Comparative Analyses in a Life Cycle Perspective
  • 2008
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Forest fuels can be recovered, stored and handled in several ways and these different ways have different implications for CO2 emissions. In this thesis, comparative analyses were made on different forest-fuel systems. The analyses focused on the recovery and transport systems. Costs, primary energy use, CO2 emissions, storage losses and work environment associated with the use of forest fuel for energy were examined by using systems analysis methodology in a life cycle perspective. The bundle system showed less dry-matter losses and lower costs than the chip system. The difference was mainly due to more efficient forwarding, hauling and large-scale chipping. The potential of allergic reactions by workers did not differ significantly between the systems. In difficult terrain types, the loose material and roadside bundling systems become as economical as the clearcut bundle system. The stump and small roundwood systems showed the greatest increase in costs when the availability of forest fuel decreased. Stumps required the greatest increase in primary energy use. Forest fuels are a limited resource. A key factor is the amount of biomass recovered per hectare. Combined recovery of logging residues, stumps and small roundwood from thinnings from the same forest area give a high potential of reduced net CO2 emissions per hectare of forest land. Compensation fertilization becomes more cost-effective and the primary energy use for ash spreading becomes low – about 0,25‰. The total amount of available forest fuel in Sweden is 66 TWh per year. This would cost 1 billion €2007 to recover and would avoid 6.9 Mtonne carbon if fossil coal were replaced. In southern Sweden almost all forest fuel is obtainable in high-concentration areas where it is easy to recover. When determining potential CO2 emissions avoidance, the transportation distance was found to be less important than the other factors considered in this work. The type of transportation system did not have a significant influence over the CO2 avoided per hectare of forest land. The most important factor analysed here was the type of fossil fuel (coal, oil or natural gas) replaced together with the net amount of biomass recovered per hectare of forest land. Large-scale, long-distance transportation of biofuels from central Sweden has the potential to be cost-effective and also attractive in terms of CO2 emissions. A bundle recovery system meant that more biomass per hectare could be delivered to end-users than a pellet system due to conversion losses when producing pellets.
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