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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effect of redoxmodulation on osteoclastogenesis

Witte, Sara January 2010 (has links)
<p>During osteoclast differentiation and bone resorption the redox status in the cell display a decrease in reduction and a shift to an oxidized state. Structure, metabolism and function are some of the extensive changes that cells undergo during differentiation which alters both the extra- and intracellular redox environment. Osteoclasts express enzymes such as TRAP and NADPH oxidase which generates reactive oxygen species (ROS). ROS are molecules formed by oxygen reduction which gives these radicals at least one unpaired electron and makes them very reactive and chemically unstable. These are factors which stimulates differentiation of osteoclasts and bone resorption. RAW 264.7 cells will differentiate to osteoclasts when stimulated with RANKL and to activated macrophages when stimulated with LPS.</p><p>The aim of this project was to analyze if the redox environment is affected during differentiation of RAW 264.7 cells to osteoclasts and macrophages. The reason for this was that we aimed to se if RAW 264.7 cells could be used as an in vitro system to study the effects of redox changes in osteoclasts and macrophages and their activation.</p><p>Results from Western blot showed that protein expression of the Cysteine/Glutamate transporter xCT was up regulated with LPS and downregulated with RANKL. Results from the GSH/Cys assay show that the treatments with redox modulators did not affect the levels of GSH and Cys to a measurable extent. However the levels increased for both intracellular and extracellular GSH and Cys forms at day 4 in the control and stimulated cells. Addition of the disulfide reductant DTT affected differentiation to osteoclasts, leading to smaller osteoclasts probably due to interference with fusion of mononuclear pre-osteoclasts. Thus, down regulation of the xCT transporter could be an important mechanism to maintain a low level of free thiols shown to interfere with the differentiation to osteoclasts.</p>
2

Internetspråk : En studie i högstadieelevers språk på internet

Hultman, Jim, Jonsson, Sanny January 2009 (has links)
In this essay we describe the characteristics of the internet language used by senior-level school pupils. Our primary question formulation is: ”Which are the significant features of the youth’s internet language on a morphological, lexical, syntactical and orthographical level?” In order to answer this question we have analyzed 45 text ex-amples which is brought from two different internet forums, Bilddagboken.se and Un-gdomar.se, forums which are widely used by youths. The analysis has been made on a morphological, lexical, orthographical and syntactical level. We have also another question formulation which is: “How is emoticons used in youth’s internet conversa-tions?” Thereby we also study the use of emoticons in the examples we have analyzed.Our conclusion in this essay is that the youth’s internet language is a language that in many cases should be seen as an own language; it should be seen as an entirely new and unique way of communication. Therefore it should not be placed in any of the cat-egories you use to talk about when it comes to linguistic studies.
3

The effect of redoxmodulation on osteoclastogenesis

Witte, Sara January 2010 (has links)
During osteoclast differentiation and bone resorption the redox status in the cell display a decrease in reduction and a shift to an oxidized state. Structure, metabolism and function are some of the extensive changes that cells undergo during differentiation which alters both the extra- and intracellular redox environment. Osteoclasts express enzymes such as TRAP and NADPH oxidase which generates reactive oxygen species (ROS). ROS are molecules formed by oxygen reduction which gives these radicals at least one unpaired electron and makes them very reactive and chemically unstable. These are factors which stimulates differentiation of osteoclasts and bone resorption. RAW 264.7 cells will differentiate to osteoclasts when stimulated with RANKL and to activated macrophages when stimulated with LPS. The aim of this project was to analyze if the redox environment is affected during differentiation of RAW 264.7 cells to osteoclasts and macrophages. The reason for this was that we aimed to se if RAW 264.7 cells could be used as an in vitro system to study the effects of redox changes in osteoclasts and macrophages and their activation. Results from Western blot showed that protein expression of the Cysteine/Glutamate transporter xCT was up regulated with LPS and downregulated with RANKL. Results from the GSH/Cys assay show that the treatments with redox modulators did not affect the levels of GSH and Cys to a measurable extent. However the levels increased for both intracellular and extracellular GSH and Cys forms at day 4 in the control and stimulated cells. Addition of the disulfide reductant DTT affected differentiation to osteoclasts, leading to smaller osteoclasts probably due to interference with fusion of mononuclear pre-osteoclasts. Thus, down regulation of the xCT transporter could be an important mechanism to maintain a low level of free thiols shown to interfere with the differentiation to osteoclasts.
4

Med Andra Ord : En studie om morfologisk kunskaps samband med avkodning och ordförståelse hos elever på gymnasiet / In Other Words : A study on the relationship between morphological knowledge, decoding and word comprehension in adolescents

Andersson, Elin, Vestin, Anna January 2022 (has links)
The aim of this quantitative study was to examine if there is a correlation between morphological knowledge and decoding and between morphological knowledge and word knowledge among high school students. In order to examine the correlation between these variables, we recruited participants from two high schools in two parts of Sweden. 38 students completed and did all nine tests (two decoding, one word knowledge and six morphological knowledge). The result of our study showed, for this group, that there is a correlation between morphological knowledge and decoding and between morphological knowledge and word knowledge. The strongest correlation showed to be between morphological knowledge and word knowledge.
5

Aspects of locomotor evolution in the Carnivora (Mammalia)

Andersson, Ki January 2003 (has links)
<p>In this thesis, the shape of the distal humerus trochlea is analysed using landmark-based morphometrics and multivariate methods, with the aim of exploring locomotor evolution in carnivorans. Elbow joint morphology is used together with body size and craniodental morphology to characterize past and present carnivorans. Evolutionary implications are studied at the ordinal, familial, and species levels, testing specific hypotheses about scaling, morphological constraints, evolutionary trajectories, and potential for social pack-hunting behaviour. The circumference of the distal humerus trochlea is found to be highly correlated with body mass, and appears to scale similarly throughout the order Carnivora. A general predictive model for carnivoran bodymass is presented (a=0.601; b= 2.552; r2=0.952, SEE=0.136, p<0001, n=92), which removes the need for the investigator to actively choose between the diverging estimates that different predictors and their equations often produce. At the elbow joint, manual manipulation and locomotion appear to be conflicting functions, thus suggesting mutually exclusive lifestyles involving either forelimb grappling or pursuit. At large body sizes, carnivorans are distributed over a strongly dichotomised pattern (grappling or locomotion), a pattern coinciding with the postulated threshold in predator-prey size ratio at 21.5-25 kg. This pattern is compared to that of two carnivoran faunas from the Tertiary. In the Oligocene (33.7-23.8 Myr BP), the overall pattern is remarkably similar to that observed for extant Carnivora. In the Miocene (23.8-11.2 Myr BP) carnivores show a similarly dichotomised pattern as the Oligocene and Recent, although the whole pattern is shifted towards larger body sizes. This difference is suggested to be a reflection of the extraordinary species richness of browsing ungulates in the early Miocene of North America. Such an increase in prey spectrum would create a unique situation, in which large carnivores need not commit to a cursorial habitus in order to fill their nutritional requirements. Finally, the elbow joints and craniodental morphology (14 measurements) of fossil canids were examined with the aim of assessing the potential for pack-hunting in fossil canids. It is clear that small and large members of the Recent Caninae share similar craniodental morphologies. However, this pattern is not present in Borophaginae and Hesperocyoninae. In the latter, large representatives are characterized by being short-faced, with reduced anterior premolars and enlarged posterior premolars, thus approaching a “pantherine-like” craniodental configuration. These traits are interpreted as an adaptation for killing prey with canine bites. It is similarly determined that, unlike recent Caninae, all analyzed species of borophagines and hesperocyonines have retained the ability to supinate their forearms. It is therefore likely that manual manipulation was part of their hunting behaviour, thus removing an essential part of the argument for social pack-hunting in these forms, as the benefits of such a strategy become less obvious.</p>
6

Ultrastructural Studies of the Airway Epithelium in Airway Diseases

Shebani, Eyman January 2006 (has links)
<p>Ultrastructural studies of airway epithelium in airway disease are important for diagnosis and understanding the underlying pathology which helps clinicians to improve the patients' treatment.</p><p>Airway biopsies from a 5-month old boy with respiratory problems and gastro-oesophageal reflux were studied by transmission electron microscopy (TEM). The tracheal columnar cells showed accumulation of lamellar bodies, indicative of lysosomal storage disease. The patient was diagnosed with Gaucher disease type 2.</p><p>Shedding of airway epithelial cells is commonly found in asthma. The attachment of these cells to the basal lamina was investigated by TEM of biopsies from patients with asthma and healthy controls. The contact area between columnar cells and basal lamina in asthmatics was significantly less than in controls. Attachment of columnar cells to the basal lamina occurs mainly indirectly, via desmosomal attachment to basal cells. </p><p>Primary ciliary dyskinesia (PCD) is a congenital disease. It is important to differentiate PCD from acquired (secondary) ciliary dyskinesia (SCD). The number of dynein arms determined by TEM was 1.5 and 1.4 for outer and inner dynein arms, respectively in PCD, versus 7.9 and 5.2 for controls and 8.1 and 5.9 in SCD. Compared to PCD patients, SCD patients have more structurally abnormal cilia. A significant difference was found in orientation of the central microtubule pair between PCD and SCD, but also overlap. </p><p>Leukotriene receptor antagonists are a new treatment for asthma. Both corticosteroids and montelukast caused apoptosis and necrosis of airway epithelial cells, and reduced the expression of intercellular adhesion molecule-1. Treatment of cells with tumor necrosis factor-α or interferon-γ reduced the fraction of the lateral cell membrane occupied by desmosomes and this effect was counteracted by corticosteroids. </p>
7

Aspects of locomotor evolution in the Carnivora (Mammalia)

Andersson, Ki January 2003 (has links)
In this thesis, the shape of the distal humerus trochlea is analysed using landmark-based morphometrics and multivariate methods, with the aim of exploring locomotor evolution in carnivorans. Elbow joint morphology is used together with body size and craniodental morphology to characterize past and present carnivorans. Evolutionary implications are studied at the ordinal, familial, and species levels, testing specific hypotheses about scaling, morphological constraints, evolutionary trajectories, and potential for social pack-hunting behaviour. The circumference of the distal humerus trochlea is found to be highly correlated with body mass, and appears to scale similarly throughout the order Carnivora. A general predictive model for carnivoran bodymass is presented (a=0.601; b= 2.552; r2=0.952, SEE=0.136, p&lt;0001, n=92), which removes the need for the investigator to actively choose between the diverging estimates that different predictors and their equations often produce. At the elbow joint, manual manipulation and locomotion appear to be conflicting functions, thus suggesting mutually exclusive lifestyles involving either forelimb grappling or pursuit. At large body sizes, carnivorans are distributed over a strongly dichotomised pattern (grappling or locomotion), a pattern coinciding with the postulated threshold in predator-prey size ratio at 21.5-25 kg. This pattern is compared to that of two carnivoran faunas from the Tertiary. In the Oligocene (33.7-23.8 Myr BP), the overall pattern is remarkably similar to that observed for extant Carnivora. In the Miocene (23.8-11.2 Myr BP) carnivores show a similarly dichotomised pattern as the Oligocene and Recent, although the whole pattern is shifted towards larger body sizes. This difference is suggested to be a reflection of the extraordinary species richness of browsing ungulates in the early Miocene of North America. Such an increase in prey spectrum would create a unique situation, in which large carnivores need not commit to a cursorial habitus in order to fill their nutritional requirements. Finally, the elbow joints and craniodental morphology (14 measurements) of fossil canids were examined with the aim of assessing the potential for pack-hunting in fossil canids. It is clear that small and large members of the Recent Caninae share similar craniodental morphologies. However, this pattern is not present in Borophaginae and Hesperocyoninae. In the latter, large representatives are characterized by being short-faced, with reduced anterior premolars and enlarged posterior premolars, thus approaching a “pantherine-like” craniodental configuration. These traits are interpreted as an adaptation for killing prey with canine bites. It is similarly determined that, unlike recent Caninae, all analyzed species of borophagines and hesperocyonines have retained the ability to supinate their forearms. It is therefore likely that manual manipulation was part of their hunting behaviour, thus removing an essential part of the argument for social pack-hunting in these forms, as the benefits of such a strategy become less obvious.
8

Ultrastructural Studies of the Airway Epithelium in Airway Diseases

Shebani, Eyman January 2006 (has links)
Ultrastructural studies of airway epithelium in airway disease are important for diagnosis and understanding the underlying pathology which helps clinicians to improve the patients' treatment. Airway biopsies from a 5-month old boy with respiratory problems and gastro-oesophageal reflux were studied by transmission electron microscopy (TEM). The tracheal columnar cells showed accumulation of lamellar bodies, indicative of lysosomal storage disease. The patient was diagnosed with Gaucher disease type 2. Shedding of airway epithelial cells is commonly found in asthma. The attachment of these cells to the basal lamina was investigated by TEM of biopsies from patients with asthma and healthy controls. The contact area between columnar cells and basal lamina in asthmatics was significantly less than in controls. Attachment of columnar cells to the basal lamina occurs mainly indirectly, via desmosomal attachment to basal cells. Primary ciliary dyskinesia (PCD) is a congenital disease. It is important to differentiate PCD from acquired (secondary) ciliary dyskinesia (SCD). The number of dynein arms determined by TEM was 1.5 and 1.4 for outer and inner dynein arms, respectively in PCD, versus 7.9 and 5.2 for controls and 8.1 and 5.9 in SCD. Compared to PCD patients, SCD patients have more structurally abnormal cilia. A significant difference was found in orientation of the central microtubule pair between PCD and SCD, but also overlap. Leukotriene receptor antagonists are a new treatment for asthma. Both corticosteroids and montelukast caused apoptosis and necrosis of airway epithelial cells, and reduced the expression of intercellular adhesion molecule-1. Treatment of cells with tumor necrosis factor-α or interferon-γ reduced the fraction of the lateral cell membrane occupied by desmosomes and this effect was counteracted by corticosteroids.
9

Fallen som föll : en studie av kasusbortfall i ett medeltida brev

de Faire, Niclas January 2009 (has links)
No description available.
10

Extra- and intrafusal muscle fibre type compositions of the human masseter at young age. : In perspective of growth and functional maturation of the jaw-face motor system.

Österlund, Catharina January 2011 (has links)
Muscles control body posture and movement by extrafusal and intrafusal (muscle spindle) fibres. The purpose of this thesis was to provide insight into the muscular basis for human jaw function at young age. Extrafusal and intrafusal fibres in the young masseter, and for comparison young biceps, were examined for composition of fibre types and myosin heavy chain (MyHC) isoforms by means of morphological, enzyme-histochemical, biochemical and immuno-histochemical techniques. For evaluation of plasticity during life span the data for young muscles were compared with previous reported data for adult and elderly muscles. The results showed significant differences in extrafusal fibre types and MyHC expression between young masseter and young biceps and between young masseter and masseter in adults and elderly. Compared with young biceps, young masseter was more intricate in composition of extrafusal MyHC expression. Muscle spindles were larger and more frequent in the masseter than in the biceps. Masseter and biceps muscle spindles showed fundamental similarities but also marked differences in MyHC expression. The results suggest that the young masseter is specialized in fibre types already at young age and shows a unique fibre type growth pattern. Whereas masseter extrafusal fibres display marked plasticity in fibre types and MyHC isoforms during life span muscle spindles/intrafusal fibres are morphologically mature already at young age and precede extrafusal fibres in growth and maturation. Results showed similarities in intrafusal MyHC expression between young masseter and biceps, but also differences implying muscle specific proprioceptive control. Differences in fibre types and MyHC expression between young masseter and young biceps extrafusal fibres are proposed to reflect diverse evolutionary and developmental origins and accord with the masseter and biceps being separate allotypes of muscle.

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