This paper gives an introduction to the theory of minimal surfaces. It is in- tended for undergraduate students with some basic knowledge of differential geometry and complex analysis.After defining the concept of minimal surface and giving a brief histo- rical survey, we look at some well-known minimal surfaces and a few of their characteristic properties. The connection between minimal surfaces and harmonic functions is discussed and the Weierstrass-Enneper represen- tation formulas are introduced. We also present Bjo?rling?s problem and give some examples. .

In Sweden there are about 4 million hectares of bare peat (mire). This land has great potential to be transformed into productive forest land, provided drainage is carried out and, in some cases, even fertilization with ashes. Drainage of mires is necessary because the high groundwater table prevents trees from growing due to reduced oxygen availability. Some of the key nutrients that trees need to grow appear in too small quantities in mires, especially potassium (K) and phosphorus (P). Ash from the combustion of biomass contains these elements and is therefore suitable as a fertilizer.

Reindeer husbandry and Forestry are both area related industries and will in big extent use the same lands. Conflicts often arise because of that the industries have different interests. Many of the activities done by the forestry influences the reindeer husbandry in an undesirable way, simultaneously as the reindeer husbandry activities can have negative consequences for the forestry. One such forestry activity is fertilization. It was during the 1960´s forest fertilization began to be practiced and the reason was that the increase in growth that the fertilization gave could be able to cover for the future shortage in wood many feared. During the 1970´s when the fertilizing activities were most intensive about 200 000 ha was fertilized annually.

Syfte: Syftet med denna in vitro studie var att testa 8 olika växtextrakt (kanel, nejlika, tranbär, aronia, humle, lime, grönt te, timjan) på två av Streptococcus mutans egenskaper, biofilmbildning och syraproduktion, samt mäta totala fenolmängden i varje växtextrakt. Material och metod: Vattenbaserat (humle, aronia, tranbär, grönt te) och etanolbaserat (nejlika, kanel, timjan, lime) växtextrakt testades på S. mutans biofilmbildning och syraproduktion. Biofilmen framställdes i mikrotiterplattor. Bacto? Todd Hewitt Broth näringslösning och en nyligen isolerad stam av S.

I Sverige och övriga världen ses en ökad resistensutveckling mot anthelmintika hos ett flertal parasiter. Spolmasken, Parascaris equorum, är en av hästens vanligaste parasiter. För diagnos av läkemedelsresistens hos hästens spolmask används idag FECRT-metoden (faecal egg count reduction test). Detta trots att metoden varken är utvecklad eller validerad för detta ändamål. Det finns dock ingen annan metod att tillgå.

The poultry red mite, Dermanyssus gallinae, is a common problem in poultry facilities, causing great discomfort for the hens and effecting the production economically. Few efficient acaricides are available and there is a need for new control methods since resistance has become a problem in some cases. The aim of this study was to evaluate the efficiency of the new liquid silica control agent Ectopar, on the poultry red mite. An initial in vitro test of Ectopar and its two components individually was performed, where live mites were sealed in together with filter paper impregnated with one of the three solutions prepared. The survival of the mites was thereafter recorded repeatedly during a period of 120 hours and compared to a control. For the field study, two poultry farms with different housing systems were used, one with furnished cages (farm 1) and one with a single tier floor system (farm 2).

The fungus Gremmeniella abietina causes damage to conifers that can lead to tree death. In 1999 and 2001 the pathogen caused severe attacks in Sweden, where about 500 000 ha of pine forest were affected. Trees of all ages were attacked, but mainly forests between 30-60 years that were ready for their first commercial thinning. After recommendations from the forest agency, sanitary fellings were made to trees that had more needle loss than 85%, a total of about 50 000 ha. Economic losses have been estimated to more than one billion SEK.

Large areas of Lodgepole pine (Pinus contorta var. latifolia) were planted in the 1970s - and '80s. The purpose of the fast-growing species was to increase growth and with short rotation periods allow a rapidly increased harvest level. Today a large proportion of the young forests owned by Holmen Skog, Iggesund are covered by Lodgepole pine and an active forest management is required to spread the harvested volume over time which is desirable by a market perspective. The purpose of this essay is to investigate the possibility of spreading the harvested volume of Lodgepole pine over time.

Ungefär vart femte par i fertil ålder drabbas av ofrivillig barnlöshet och många av dem genomgår då in vitro-fertilisering (IVF). Infertilitet och IVF- behandling kan leda till att upplevelsen av sig själv och sitt förhållningssätt till andra förändras och detta kan medföra ett lidande för kvinnorna. Antalet IVF behandlingar ökar för varje år och syftet med examensarbetet är att belysa kvinnors upplevelse under IVF- behandling. Genom en ökad kunskap kan vårdpersonal på ett mer tillfredställande sätt möta kvinnor som genomgår fertilitetsbehandlingar och minska deras lidande. Den valda metoden är en kvalitativ innehållsanalys och litteraturen är begränsad till självbiografier, som ger en mer detaljrik inblick i kvinnornas livsvärld.

Eutrophication is an environmental problem that affects more than ten percent of Swedish lakes. Excess nutrients increase the growth of algae, and cause major problems in the ecosystem through oxygen-free bottoms, fish kills, and at worst dead bottoms. Agriculture accounts for 44% of human emissions of phosphorus to lakes and rivers. Leaching occurs of particle bound phosphorus and of dissolved phosphate. The amount of phosphate in the soil solution that may be leached is partly due to the prevailing pH in the soil solution. The purpose of this study was to investigate how the relationship between phosphate solubility and pH was affected by liming.

En publicerad metod för undersökning av noggrannhet hos DNA polymeraser har undersökts. Metoden bygger på in vitro replikation av lacZ? genen i pUC18 och identifiering av mutationer genom blå vit selektion efter transformation av reaktionsprodukten. I arbetet visas att framställning av templatet till polymerasreaktionen kan göras enligt beskrivning, men att utbytet blev lågt. Polymerasreaktionen med det framställda templatet fungerade även det enligt beskrivning men mängden erhållen produkt var för liten för att ge kolonier efter transformationssteget.

På grund av stora resistensproblem måste användningen av antibiotika i världen minska. För att kunna genomföra detta måste alternativa preparat börja användas. I detta arbete görs en utvärdering av fyra topikalt administrerade preparat som används vid behandling av infekterade sår. De preparat som utvärderas är honung, jod, hydrofoba förband (Sorbact) och polyhexametylenbiguanid (PHMB). Utifrån de fakta och studier som finns tillgängliga i dagsläget görs en utvärdering av preparaten utifrån deras effekt, hur toxiska de är och om de selekterar för resistens hos bakterier. Med hänsyn till detta ges svar på frågan huruvida dessa preparat är lämpliga substitut till antibiotika vid behandling av sårinfektioner. Vid sammanställning av studierna kunde det konstateras att tre av preparaten hade en baktericid effekt in vitro.

Simplicity, intimacy, freedom and one single threadcharacterize the knitting technique.In my project, I have studied ways of creating three-dimensional shape and structure using single threads and various knitting techniques. I applied my ideas in a collaboration with the singer Sofia Karlsson. The focus has been to design a portable object that can be used in pictures for the cover and promotion of her upcoming album.The material I studied, processed and used in creating the three-part object was linen. In the center stands a collar, that changes expression depending on how it is worn and which side is turned towards the outside. The collar interacts with a cylinder for her hands and a hairnet.

Agricultural soils constitute the base in human food production and soil content of organic matter and plant nutrients together with soil microbial activity are all important parameters for high crop yield of good quality. These parameters are dependant on proper fertilization.Anaerobic digestion of organic wastes for biogas production generates a liquid residue called biogas residue (BR). It contains organic material and plant nutrients which makes ita potential fertilizer for arable cropping. However, it also contains heavy metals and toxic organic compounds and it is therefore in need of evaluation before usage.Microbial tests were performed aiming to evaluate the agronomic traits of four different BR and to find a viable procedure for evaluating slurry fertilizers. Two experiments where soil respiration and soil potential denitrification activity (PDA) was measured at fertilizer addition were performed.

In this trial we used QualispermTM as an objective method of measuring stallion semen. Samples of semen were analyzed before and after centrifugation. Motility and concentration were statistically analyzed. During the trial all the objective mesaurments were compared to a subjective method. The advantages of QualispermTM compared to older CASA- systems is it´s ability of measuring a greater amount of spermatozoa while it also grades them into different subpopulations. These subpopulations have different qualities that decides their capacity of fertilization. The results showed that this objective method might be used practically. Although, there are still some disadvantages, such as high costs and the necessarity of accurat training of the handler. If it´s possible to prove further relevant results that also are statistically correct, this could prove the usefulness of QualispermTM as an objective measurment method in the daily work at gestuts and stallion stations, thus giving the staff a reliable instrument in assisting the work for an improved horse breeding in Sweden, improving both in quality and economically..