Sökresultat

The growth rates and motility of dinoflagellates were studied in the field in the presence or absence of UVB radiation, as well as in the laboratory under artificial radiation conditions. Photosynthetically active radiation (PAR, 400–700 nm) and UVB radiation showed large variations due to cloud cover and seasonal changes in natural daylight. In Swedish coastal water, UVB radiation was attenuated

In northern Patagonia, macrolichens form species-rich and abundant epiphytic communities in southern beech forests. Five of the most abundant lichen species in the litter were selected in order to study mass loss rate and changes in mineral composition over time. The litter bag method was applied to the foliose lichens Pseudocyphellaria faveolata, Pseudocyphellaria flavicans, Nephroma antarcticum,

A method with low MDL (minimum detection limit) was developed for analysis of carbon (C), nitrogen (N) and oxygen (O) in aerosol samples collected on an organic backing. An accelerator-produced beam of protons interacting with the sample and the detection of elastically scattered protons (PESA; particle elastic scattering analysis) and emitted X-rays (PIXE; particle-induced X-ray emission) were th

Popular Abstract in Swedish Döva barns begreppsbildning i matematik Denna studie tar utgångspunkt i frågan varför många döva barn har svårt att lära sig matematik. Studiens syfte är att belysa döva barns begreppsbildning i ämnet matematik genom att beskriva hur några döva barn uttrycker sig och agerar på väg mot förståelse av två centrala matematiska begrepp, nämligen multiplikation med heltal ochThe question why deaf children have difficulties in learning mathematics is the basis of this study. The aim of the study is to illuminate deaf children’s concept formation in mathematics by describing how some deaf children express themselves and act on their way towards understanding two basic concepts, the concept of multiplication with whole numbers and the concept of length. Theories develope

To explore the spatial variation of the soil microbial community within a mixed Norway spruce-birch stand, and to test if the spatial patterns of the microbial community are related to the position of trees, we sampled the forest floor at two spatial scales and used the phospholipid fatty acid (PLFA) patterns as indicators of the microbial community structure. Of the 32 most common PLFAs, 20 (62%)

BACKGROUND: Development of proximal and distal colorectal cancers involve partly different mechanisms associated with the microsatellite instability (MSI) and the chromosomal instability (CIN) pathways. Colorectal cancers in patients under 50 years of age represent about 5% of the total number of tumors and have been associated with an increased frequency of MSI tumors. However, MSI and CIN may pl

The chromosomal location of six barley genes was determined by Southern blot experiments using wheat strains which contained the short or long arm from one of the seven barley chromosomes. The genes analysed encode enzymes that are required for chlorophyll and heme synthesis. Glutamyl-tRNAGlu synthetase, glutamate 1-semialdehyde 2,1-aminotransferase and glutamyl-tRNAGlu reductase are common to bot

Commercial decabromodiphenyl ether (DecaBDE) is commonly used as a flame retardant in different electrical and textile applications. It is also used in the production of flame-retarded rubber compound. DecaBDE is the major technical polybrominated diphenyl ether (PBDE) in use today and consists mainly of decabromodiphenyl ether(BDE209). PBDEs, including BDE-209, are well-known environmental pollut

The hydrophilic/hydrophobic properties of the membrane material have an important influence on the membrane flux reduction when treating solutions containing hydrophobic solutes. Different methods of measuring the hydrophobic properties of membranes have been evaluated; measurement of the contact angle being the most commonly used method. In this investigation the flux reduction of eight membranes

A method based on computational fluid dynamics (CFD) for the characterization of static mixers using the Z factor, helicity and the rate of striation thinning is presented. These measures were found to be well-suited for the characterization of static mixers as they reflect the pressure drop, the formation of secondary flow, i.e. vortices, and their effect on the mixing process. Two commercial sta

Background: Gastrectomy, specifically the removal of the acid-producing part of the stomach (fundectomy), is known to cause osteopenia. This effect has been ascribed to the elimination of a hypothetical osteotropic peptide hormone, presumably produced in the oxyntic mucosa. Since osteopenia is due to a disturbed balance between bone formation and resorption, we assessed the effect of gastrectomy o

The search for significantly overrepresented and co-occurring transcription factor binding sites in the promoter regions of the most differentially expressed genes in microarray data sets could be a powerful approach for finding key regulators of complex biological processes. To test this concept, two previously published independent data sets on wounded human epidermis were re-analyzed. The prese

The effect of ozone additive on the enhancement of the burning velocity for premixed methane-air flames is investigated by both experimental measurements and kinetic simulations. Laminar burning velocities with and without O(3) were directly measured using the Heat Flux method. The O(3) molecules were introduced into the system by a dielectric-barrier-discharge ozone generator installed in the O(2

Background: Lumbar spine radiography has limited diagnostic value but low radiation dose compared with computed tomography (CT). The average effective radiation dose from lumbar spine radiography is about 1.1 mSv. Low-dose lumbar spine CT may be an alternative to increase the diagnostic value at low radiation dose, around 1 mSv. Purpose: To determine the optimal settings for low-dose lumbar spine

Thin semitransparent gels were prepared by radical copolymerization of N-acryloyl-m-aminophenylboronic acid (NAAPBA) and acrylamide (AAm) taken in molar ratios from 8:92 to 16:84, respectively, in water. The gels were characterized by the content of immobilized NAAPBA and monomer conversion. Scanning electron microscopy revealed the micrometer size pores in the dried gels. The wet gels displayed a

The hairdresser occupation is classified as probably carcinogenic to humans based on an excess risk for urinary bladder cancer, but it is unclear if current work as a hairdresser entails such a risk. The overall aim of this thesis was to investigate if hairdressers have an ongoing exposure to selected carcinogenic aromatic amines. We recruited 295 hairdressers, 32 consumers of hair dyes and 60 co

Popular Abstract in Swedish Diabetes är en grupp sjukdomar som alla kännetecknas av en förhöjd nivå av sockerarten glukos i blodet. Antalet individer som drabbas av diabetes ökar hela tiden, en utveckling som ses över hela världen. Bara i Sverige har drygt 5% av befolkningen diagnosen diabetes, motsvarande 484.400 personer i åldern 20-79 år. Typ 2 diabetes är den vanligaste formen av diabetes, ochThe incidence of diabetes is increasing worldwide, with the most prevalent form being type 2 diabetes. Two fundamental processes contribute to the development of type 2 diabetes: insulin resistance in target organs and insufficient insulin secretion from the pancreatic beta-cells. The aim of this thesis was to explore the role of DNA methylation and common genetic variation on glucose metabolism a

Population fluctuations and synchrony influence population persistence; species with larger fluctuations and more synchronised population fluctuations face higher extinction risks. Here, we analyse the effect of diet specialisation, mobility, length of the flight period, and distance to the northern edge of the species' distribution in relation to between-year population fluctuations and synchrony

Background-Although the heritability of atrial fibrillation/atrial flutter (AF/AFl) has been determined, the familial risk in multiplex families is unclear. The main aim of this nationwide study was to determine the familial risk of AF/AFl in multiplex families. Methods and Results-We examined the familial risk of AF/AFl in the entire Swedish population. We linked Multigeneration Register data on

Asthma is characterized, not only by inflammation but also by airway and vascular remodeling. Airway remodeling is established early in disease, structural alterations have been found in children, and is thought to contribute to asthma symptoms. Unfortunately, airway remodeling is considered difficult to reverse and it seldom resolves completely. Studies of vascular involvement in asthma have main