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This thesis describes experimental studies that aim to stabilise and optimise laser-based particle accelerators. The technique is called laser wakefield acceleration, where electric fields of the order of 102 GV/m accelerate electrons to high energies (⇠102 MeV) over mm-distances in laser-produced plasmas. Among the prerequisites for this acceleration technique to produce electron beams are laser
Starting university is associated with major academic, personal and social opportunities. For many people, university entrance is also associated with increased stress and alcohol consumption. At the start of the autumn term 2002, all students entering educational programmes at two comparable middle-sized Swedish universities were invited to participate in a comparative intervention study. This in
Introduction Aniridia (iris more or less missing), is a congenital, dominant, inherited, serious and sight-threatening disease, most often appearing as an isolated eye disorder. It is caused by mutations in the PAX6 gene, the master gene of the development of the eye. Typically, Aniridia causes severe visual impairment. In addition to glare caused by the iris defect, underdevelopment of the macula
Objectives: To assess the contribution of out-of-home (OH) energy and nutrient intake to total dietary intake, and to compare out-versus in-home nutrient patterns among 27 centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Methods: Between 1995 and 2000, 36 034 participants aged between 35-74 years completed a standardized 24-h d
Abstract in Danish I den vestlige del af Limfjorden findes en række kystklinter, hvor eocæne lag er blottet. Moler er en ca. 55-56 millioner år gammel diatomit, som indeholder lag af uforvitret vulkansk aske samt et stort antal velbevarede marine og terrestriske fossiler. Stolleklint Leret og Fur Formationen har et usædvanligt fossilselskab med mange repræsentanter for insekter, fisk, fugle og ski
Ionization injection is a simple and efficient method to trap an electron beam in a laser plasma accelerator. Yet, because of a long injection length, this injection technique leads generally to the production of large energy spread electron beams. Here, we propose to use a shock front transition to localize the injection. Experimental results show that the energy spread can be reduced down to 10
In the recent years, there has been an increase in applications of non-contact diffusion optical tomography. Especially when the objective is the recovery of fluorescence targets. The non-contact acquisition systems with the use of a CCD-camera produce much denser sampled boundary data sets than fibre-based systems. When model-based reconstruction methods are used, that rely on the inversion of a
The sun and its heat are two of the most universal symbols known to humanity, yet their supposed meanings vary greatly. The sun can be thought of as a giver of life, but its hot and scorching rays can also be associated with drought and the powers of destruction. The present study concerns the latter view of the sun and related ideas as reflected in the Hebrew Bible and the cuneiform alphabetic te
Purpose: The aim of this article is to explore how trustworthy knowledge claims in Wikipedia are constructed by focusing on the everyday practices of Wikipedia editors. The article focuses particularly on the role of references to external sources for the stabilisation of knowledge in Wikipedia. Design/methodology/approach: The study is inspired by online ethnography. It includes eleven Wikipedia
Syftet med denna studie är att utifrån mitt empiriska material kartlägga och beskriva hur de anställda på de särskilda ungdomshemmen tolkar, definierar, och upplever ett behandlingsprojekt, som involverade olika myndigheter, benämnt Motverka Våld och Gäng. Dessutom uppmärksammas hur de anställda samordnarna uppfattades och kategoriserades. I institutionspersonalens framställning är samordnarens The aim of this study is to map out and describe the way employees in Swedish juvenile homes interpret, define and perceive, on the one hand, the project “Motverka Våld och Gäng” meaning “Counteract Violence and Gangs”, and on the other hand the role of the Coordinators employed in this project. The role of the Coordinator is formally clear and unproblematic. The project management directives sta
A laser pulse traveling through a plasma can excite large amplitude plasma waves that can be used to accelerate relativistic electron beams in a very short distance-a technique called laser wakefield acceleration. Many wakefield acceleration experiments rely on the process of wave breaking, or self-injection, to inject electrons into the wave, while other injection techniques rely on operation wit
Drying and rewetting is a frequent physiological stress for soil microbial communities; a stress that is predicted to grow more influential with future climate change. We investigated the effect of repeated drying-rewetting cycles on bacterial (leucine incorporation) and fungal (acetate in ergosterol incorporation) growth, on the biomass concentration and composition (PLFA), and on the soil respir
The amyloid beta (A beta) peptides (mainly A beta 40 and A beta 42), which are derived from the amyloid precursor protein (APP), can oligomerize into antibody A11-positive, neurotoxic species, believed to be involved in Alzheimer's disease. Interestingly, APP binds strongly to the heparan sulfate (HS) proteoglycan (PG) glypican-1 (Gpc-1) in vitro and both proteins are colocalized inside cells. In
Older people have more functional limitations than younger people and they form a segment of the population that is more dependent on mobility devices than other age groups. Since they spend most of their time at home, their dwelling is an important environmental arena for performing everyday activities. Barriers in the environment can limit or hinder activity performance. Therefore, older people
Background: Early developmental conditions can influence within- and among-brood variation in the timing of hatching/birth, which has been shown to affect offspring survival, growth, and reproductive success across a range of species. Problem: How does within- and among-litter variation in the timing of birth affect offspring growth and survival in Egernia whitii? Organism: Egernia whitii, a l
The formation of chondrules is one of the oldest unsolved mysteries in meteoritics and planet formation. Recently an old idea has been revived: the idea that chondrules form as a result of collisions between planetesimals in which the ejected molten material forms small droplets that solidify to become chondrules. Pre-melting of the planetesimals by radioactive decay of Al-26 would help produce sp
Purpose: To what extent active surveillance and deferred treatment for localized risk prostate cancer are used is unclear. We assessed the use of surveillance and of deferred treatment in a population based, nationwide cohort in Sweden. Materials and Methods: In the National Prostate Cancer Register of Sweden, with a 98% coverage vs the compulsory Swedish Cancer Registry, we identified 8,304 incid
A novel sequential injection method for the determination of nitrite at nanomolar level in seawater samples has been developed. The pink azo compound was formed based on the Griess reaction and quantitatively adsorbed onto a Sep-Pak C18 cartridge. The enriched azo compound was rinsed with water and ethanol (28%, v/v) in turn, and then eluted with an eluent containing 26.6% (v/v) ethanol and 0.108m
