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Prior Knowledge and Recognition Memory : a Computational Modeling Approach

For more than a century, an immense interest has been devoted to the study of recognition memory, where a multitude of memory phenomena has been explained. Recognition memory is usually described with parsimonious measurement and statistical models, stemming from dual process theory and signal detection theory. In the present thesis, the most often used models of recognition memory are reviewed an

Contact allergens in p-tert-butylphenol-formaldehyde resin

p-tert-Butylphenol-formaldehyde resin (PTBP-F-R) is used as a binder in many adhesive formulations and it consists of a complex mixture of substances, most of which are unknown. The resin has been reported to cause allergic contact dermatitis since the 1950s. The aim of the study was to investigate allergens in p-tert-butylphenol-formaldehyde resin (PTBP-F-R) and to isolate and identify sensitizer

Transmission Electron Microscopy of III-V Nanowires and Nanotrees

In this work, the morphology and crystal structure of epitaxial semiconductor nanowire structures grown by metal-organic vapour phase epitaxy (MOVPE) are studied by electron microscopy methods. In particular, the three-dimensional structure of nanowires and nanotrees has been characterised by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and multi-sli

Structure and Interactions of the Extracellular Matrix Protein PRELP

This thesis describes the structure and interactions of a novel extracellular matrix protein - PRELP (proline arginine-rich end leucine-rich repeat protein). The amino acid sequence of PRELP showed that it belonged to the leucine-rich repeat (LRR) protein family in connective tissues. The main part of PRELP is composed of 10 LRRs flanked by disulfide bridges at the amino- and carboxy-terminal end

Parental participation in paediatric surgical care. Clinical, ethical and economic considerations.

In order to deliver optimal paediatric care, we need to know what children and their parents need, expect, and experience. Thus, the general aim of the studies upon which this thesis is based was to elucidate different aspects of parental participation in the care of their child during hospitalisation for paediatric surgery, a specific aim being formulated for each of the four studies. The aim of

On the lateral organisation of the thylakoid membrane

In this work the lateral heterogeneity of the thylakoid membrane was investigated by quantifying the amount of photosystem I (PSI), photosystem II (PSII) and some PSII complexes and PSII proteins in different domains of the thylakoid. Grana, grana core, grana margins and stroma lamellae + end fractions were obtained by sonication and separation in a non-detergent, aqueous polymer two-phase system

Glacial history of Northeast Greenland: cosmogenic nuclide constraints on chronology and ice dynamics

The aim of this thesis was to use cosmogenic exposure dating to investigating whether highly weathered landscapes in the Northeast Greenland fjord zone have developed during prolonged ice free conditions or have been preserved beneath cold-based ice. Previous work along the Northeast Greenland coast has presented two conflicting hypotheses for the extent of the Greenland Ice Sheet during the last

The complex world of proteins: Structure, function, and oligomerization of frataxin

Patients suffering from the deadly progressive neurodegenerative disease Friedreich's ataxia have reduced levels of expression of the protein frataxin. Yeast frataxin has been extensively studied in vitro, and has been shown to deliver iron to heme and iron-sulfur cluster biosynthesis, as well as to oligomerize in the presence of iron. In this dissertation metal-dependent oligomerization of fratax

The immunomodulatory properties of C-Med 100 an extract of the plant Uncaria tomentosa

Extracts from the bark of the vine Uncaria tomentosa have anti-inflammatory, antiviral, antimutagenic and antioxidant effects. In this study, we evaluate the effects of an Uncaria tomentosa extract, denoted C-Med 100, on the cellular level of the immune system both in vivo and in vitro. Our results indicated that lymphocytes had significantly prolonged half life after in vivo supplementation with

Pancreatic Growth and Secretion. An Experimental Study on Growth Factors in Rat and Mouse

The pancreas is a central organ in the digestion of food as well as in glucose metabolism. Its two major functions are exocrine and endocrine secretion. These are meticulously regulated processes that depend on hormonal response to gastrointestinal contents and blood glucose levels through feedback mechanisms, but also to the status of pancreas in health and diseases. The present thesis aimed at f

The upper gastrointestinal tract in chronic alcoholics

Background: Gastrointestinal symptoms such as dyspepsia, diarrhoea, and nausea are often seen in alcoholics. The causes are not clear. The stomach and upper small intestine are exposed to high alcohol concentrations. Yet, the majority of alcohol abusers do not exhibit macroscopic abnormalities at upper gastrointestinal endoscopy, although histological and electron microscopic (SEM) changes have be

Transvascular fluid exchange with application to the brain. An experimental study in cat skeletal muscle and brain.

This study evaluated transcapillary fluid exchange in the cat brain and in a cat skeletal muscle enclosed in a plethysmograph. A method for determination of capillary permeability (capillary filtration coefficient and reflection coefficient) and effects of transcapillary hydrostatic pressure changes were studied We found that capillary fluid permeability in a tissue can be determined by the capill

Exposure assessment for the prevention of musculoskeletal disorders

Work-related musculoskeletal disorders of shoulder/neck are a major and increasing problem. Beside the pain, they involve high cost for the employer and society. The total expenditure for the musculoskeletal disorders of the neck and upper limb have been estimated to 0.5-2.0% of the Gross National Product (GNP) in the Nordic countries. Due to the lack of precise knowledge of exposure/response rela

Respiratory NAD(P)H dehydrogenases of plants - Gene identity and expression in response to light and cold

The respiratory chain of plants contains class 2 NAD(P)H dehydrogenases, not present in animals. The functional roles of these enzymes have been elusive for a long time. Two cDNAs, homologous to class 2 NADH dehydrogenase genes of yeast and E. coli, were isolated from potato leaves. The gene products, NDA1 and NDB1, were shown to reside on the internal and external sides of the inner mitochondrial

Energy Efficient Processes for the Production of Gaseous Biofuels - Reforming and Gas Upgrading

Replacing fossil fuels with biofuels is one way of reducing the emission of greenhouse gases into the atmosphere, thus decreasing our impact on the global climate. For this to be a viable option, several production routes are needed, as no single option can fully replace fossil fuels. One way of making biofuels more competitive with fossil fuels is by reducing the production cost. As most of the p

Laser Doppler Flowmetry and Imaging: Methodological Studies

Laser Doppler flowmetry (LDF) and laser Doppler imaging (LDI) are modern methods for non-invasive and continuous assessment of skin blood flow. The techniques are based on the phenomenon that monochromatic light transilluminating a perfused tissue is spectrally broadened owing to scattering by moving blood cells. In this study, methodological aspects of the two methods are presented. LDF was used

Cytogenetic studies of normal kidney tissue and renal cell carcinoma

In the present thesis normal kidney tissue and renal cell carcinoma (RCC) were studied by cytogenetic and fluorescence in situ hybridization (FISH) methods to investigate chromosomal aberrations. In the first study, 4 samples of nonneoplastic kidney tissue were cultured for cytogenetic analysis and trisomy 7 was found in all cases in 3-15% of the cells. In the second study, cytogenetic analysis o

Aspects of Optical Broad Band Spectroscopy and Information Extraction - Applications in Medicine and Ecology

The present thesis describes a number of aspects of modern electro-optical measurement technology also known as bio-photonics; this includes instrumentation, applications, sample interaction and data interpretation. The methods employed operate over several domains, and light measurements are discretized both in intensity, space, angle, time, polarization and energy. Mainly the spectral domain is

Waterfowl herbivory on submerged macrophytes in eutrophic lakes

Submerged macrophytes are thought to stabilize clear-water states of shallow lakes. The aim of this thesis was to elucidate how waterfowl herbivory can affect abundance, distribution and species composition of submerged macrophytes in eutrophic lakes. I found that in a lake with sparse vegetation, which was in a colonization phase, small plants were uprooted and large plants were heavily grazed up

Experimental Stroke and Neurotrophins: Regulation, function and gene transfer of neurotrophins in rat and mouse models of focal cerebral ischemia

Stroke caused by focal cerebral ischemia is a major cause of death and neurological disability in humans. The forebrain region most commonly affected by ischemic incidents is that supplied by the middle cerebral artery. In this thesis, neuronal cell death has been investigated using immunohistochemistry for identification of specific neurons and unbiased counting methods after transient occlusion