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920 Uppsatser om Species interactions - Sida 49 av 62
Förekomst av törskate (Cronartium flaccidum, Peridermium pini) på tall (Pinus sylvestris) i relation till markfuktighet och fältskikt : en studie om 2000-talets törskateepidemi i norra Sverige
Resin-top disease is a rust fungi that occurs both as a host alternating form, Cronartium flaccidum G. Winter., and as a non-host alternating form, Peridermium pini Pers. The host alternating form can use a variety of hosts but the most commonly used species in the boreal forest is Melampyrum sylvaticum. In Scandinavia the Resin-top disease infect Scots pine, Pinus sylvestris L. The fungus infects the needles through the stomata and then grows through the branch to the stem where it strangulates the vessels transporting water and nutrition to the treetop, which kills the top.
Konvergenskultur ? en medieteoretisk studie : En beskrivning av mediekulturens samtida tillstånd, utifrån populärkulturella och meningsskapande praktiker och dess ramverk knutna till nutida dramaserier
Drawing from the theoretical foundations of the ?critical theory? of the Frankfurt School and the media ethnographic ?cultural studies? approach of the british Birmingham School, this study attempts to sketch out a media theoretical overview of the contemporary state of media culture. Using the term convergence culture as the foundation, this study offers a theoretical background to the two contemporary streams that are the significant and distinct tendencies of convergence culture: intermedial convergence, its contemporary state and historical tendencies that can be traced back using the past media theoretical approach of the Frankfurt School, and cultural convergence, its contemporary state and historical tendencies, which lineage in a media theoretical context can be traced back to the british ethographic ?cultural studies? field. Using contemporary drama serials to identify and pinpoint these two stream, this study shows how intermedial convergence expresses itself today through media conglomeration in terms of branding, product placement and marketing as the result of the ?completed? convergence between screen culture and popular music as the current defining state of commodity culture.
Analysis of Swedish accessions of Phaseolus vulgaris L. using SSR Markers
AbstractThe genetic diversity in cultural plants is considered to be threatened due to global climate change and antropogenic influence. Unknowing of future conditions for cultivation, gene banks all over the world are now trying to build up costly safety nets of species and varieties that may become highly valuable owing to their specific traits and genetic heredity. Hence, in 2002 there was a national inventory, aimed at the Swedish public, asking for seeds believed to be lost. Among the resulting collected seeds were some accessions of garden bean, Phaseolus vulgaris. The objective of this particular study was to assemble a collection of unique varieties and discard possible duplicates.
Skogsbränsledrivare i klen förstagallring med contorta
The aim for the study was to examine a harwarder´s (combined harvester-forwarder) productivity when harvesting forest fuel in first thinning stands that contains Lodgepole pine and calculate the economy of the harvesting work and estimate the quality of the thinning . The field study area where located near Arvån, about 15 kilometres south ?east from the city of Lycksele. The field studies were taken place in three different stands. All tree stands had the same tree age, but the tree species combination and the density varied.
Vegetationsutveckling och brandhistorik i Tyresta under 9000 år : en pollenanalytisk studie av en skvattramtallmyr i Tyresta nationalpark, Södermanland
Analyses of pollen and charcoal in peat cores, together with age-structure data of Pinus sylvestris from a Ledum-Pinus-mire in the Tyresta National Park (south-east Sweden) show the regional vegetation succession and fire history over the last 9000 years. Five major stages of mire development are identified: 1. Lake (c 7000-6400 cal BC); 2. Wet fen (c 6400-6000 cal BC); 3. Deciduous fen (c 6000 cal BC to c cal AD 700); 4.
Vattenflödets betydelse för fångster av lekvandrande lax (Salmo salar) och öring (Salmo trutta) : En utvärdering av laxfällan vid vattenkraftverket i Forshaga
Many watersheds have lost stocks of migrating fish species because of the development of hydroelectric plants and other fragmenting barriers. The remaining stocks of migrating Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) in River Klarälven, Sweden are five times smaller compared to one hundred years ago. A fish-trap at the hydroelectric plant in Forshaga has been vital for the continued existence of the stocks. This is the first hydroelectric plant of eight, blocking the way to the spawning grounds. Spawners are collected in the trap for both hatchery and transport by truck upstream and past seven more hydroelectric plants to the spawning grounds, where they are released for possible natural reproduction.
Initial evaluation of the Meritas Troponin I test for measurement of equine cardiac troponin I
Cardiac troponin I (cTnI) is considered a specific and a sensitive biomarker of cardiac disease, and due to a high inter-species sequence homology; human cTnI assays can often be used in veterinary medicine. The main aim of this study was to perform an initial evaluation of a human cTnI test, the Meritas Troponin I test, for measurement of equine plasma cTnI, in order to investigate whether the test could be a possible subject for a more comprehensive validation. The hypothesis was that the test could measure equine cTnI, as there is a good homology between equine cTnI and human cTnI.
The evaluation included a dilution parallelism, an intra-assay precision study and measurement of plasma cTnI healthy horses. In the dilution parallelism and the intra-assay precision study, equine plasma with previously established high cTnI concentration, according to another cTnI assay, was used. In addition, cTnI concentration was measured in plasma, collected from 19 horses, without signs of disease at physical and ECG examinations.
The obtained curve in the dilution parallelism was linear, indicating that the Meritas Troponin I test can be used to measure different concentrations of equine cTnI in plasma.
Stem injection of different nitrogen forms into young Norway spruce
This master thesis has been a pilot study preceding a forthcoming project of a larger scale with the long term objective to separate the direct effect of added nitrogen on soil processes from indirect effects via trees. The aim of this study has been to investigate the allocation of nitrogen following direct injection of liquid solutions into the xylem of 40 year old Norway spruce. The field site is located at Flakaliden (64°07?N, 19°27?E), approximately 60 km northwest of Umeå, Sweden. A total of 18 trees were selected for treatment, equally divided between three treatments, potassium nitrate, glutamine and water (control).
Hotbild för ädellav Megalaria grossa i Uppland och på Gotland :
Megalaria grossa is classified as Near treatened on the Swedish Red List. It is also a so called signals spieces, e. g. a spieces that function as an indicator, signalling a forest that is worthy of protection. The aim of this study was to clarify the status at selected localities in the province of Uppland and Gotland.
Barns rädslor i skogen : En studie om barns okunskap och vad de är rädda för. Samt hur pedagoger väljer att arbeta med barnens rädslor.
AbstractThe Swedish society has always been monolingual, but has for the past decades transformed into a multicultural and multilingual society. The aim of this study is to investigate if and in that case how preschool teachers work with language development in bilingual and multicultural preschools. The concept of linguistic and cultural diversity includes several different components, not least the social interactions that are of great importance to every individual's development, learning and participation in the world. By understanding the importance of language, language development and the role of mother tongue in second language acquisition, we look into various researches done concerning the effects of the preschool teachers? opinions, methods used to language developmental primarily for children who are multilingual and how the physical environment is shaped to promote language in multicultural and multilingual preschools.The method used in this study is semi-structured interviews with preschool teacher working in multicultural or bilingual preschool settings.
Utbyte av massaved och biobränsle i några typbestånd av Contorta :
The aim of this study is to describe a number of type stands of lodge pole pine in Norrbotten with respect on stem volume and total biomass. Further questions to answer is if there is stand characteristics that make the stands more suitable for pulpwood in early thinning, or if it is better to apply whole tree harvest. The study shall also give an indication if bio energy can be an economical interesting alternative for Sveaskog.
Sampled trees represented the variation in the different stands. Five trees were selected from each stand to represent that stand. Stem volume and biomass (kg dry weight (DW) per hectare) for each fraction was calculated.
Vallört som växtnäringskälla : växtnäringsförsök och litteraturstudie
Russian comfrey, Symphytum x uplandicum, was tested as a plant nutrient source in a trial with tomatoes. Comfrey liquid was produced by Stiftelsen Holma i Höör. Tomato plants of the cultivar Aromata planted in a medium of soil:peat (1:1) enriched with organic nutrients and lime, were fed with comfrey liquid plus Biofer, in three different concentrations. Two different concentrations of BioRika were used as comparison, along with an unfertilized control group. In the comfrey treatment I a total amont of 1g N, 0,23 g P, 0,84 g K, was given to the tomatoes.
Apputveckling : En studie av motsättningar mellan design- och användningspraktiker ur ett verksamhetsteoretiskt perspektiv
We live in a high tech era of electronic media, which is changing our lives (Giddens, 1999). Apps are examples of technologies that affect our lives. An interesting question in this context is what apps will have for significance; on one hand for the development of technology, and on other hand for humans? relation to technology. Since the development and change process are central issues in the science of education I will explore the development of applications.
Begomovirus susceptibility in wild Nicaraguan tomato populations
Tomato production is a common and important agricultural activity in Nicaragua. During the last decades tomato producers have suffered great yield losses due to begomoviruses (family Geminiviridae). The genome of begomoviruses generally consists of two circular ssDNA components, DNA-A and DNA-B. Tomato yellow leaf curl virus (TYLCV) is an example of a begomovirus with only one component. An approach to manage the virus epidemics has been to breed a cultivar with begomovirus resistance genes, which have been transferred from wild tomato.
Light pollution : consequences and sustainable lighting design
Light has always fascinated humans but ever since the invention of the first light
bulb, the use of artificial lighting has accelerated dramatically. Darkness has never
been as rare as today and the overuse of lighting has created a new phenomenon
called light pollution. Most living beings are biologically dependent on the
recurrent twenty-four-hour rhythm of light and darkness, called the circadian
cycle. Human beings are evolutionary developed after this circadian rhythm and
the effects of constant artificial light is yet unknown. Scientists fear the consequences
of constant lighting and what it means physically, mentally and philosophically
for the human species.