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7350 Uppsatser om Size structured population model - Sida 1 av 490

Hassel (Corylus avellana) som indikator på markanvändningshistorik

Hazel (Corylus avellana L.) is a common feature of meadows and pastures where it can grow in large populations and become very old. Is it possible to use the size of hazel stools for age determination and is it possible to use the size distribution of a population to provide information about how the land has been used? Hazel populations on ground where the lake-water level had been lowered, has been studied to validate an already developed growth model of hazel clones. Different hazel populations, on wooded meadows affected by mowing or grazing or overgrown meadows, were studied to evaluate the method utilizing hazel as land use indicator. The growth model was used to compare the size distributions of hazel populations with historical periods, which has been important for changes in agriculture or demography.

Influence of the habitat on the potential for cannibalism and population dynamics in stream-dwelling European grayling (Thymallus thymallus L.)

Cannibalism can have major influence on fish population dynamics. A prerequisite for cannibalism is that the cannibal and the potential victim meet, and besides density effects, the encounter rate between cannibals and their victims is therefore also largely dependent on habitat use and habitat heterogeneity. In this study I quantified and compared the potential for cannibalism in stream-dwelling European grayling populations in three rivers in Jämtland by means of habitat classifications. I also analyzed population dynamic consequences of varying the potential for cannibalism in terms of intensity, using a physiological structured population model. Findings based on habitat characteristics were that the potential for cannibalism is in general not favourable in these types of streams.

Rådjur (Capreolus Capreolus) på Gotland : populationsutveckling och spridningsmönster

Gotland is an island in the Baltic Sea where man has introduced roe deer. The last successful reintroduction was in the 1980s and is the base of the viable roe deer population of today.The aim of this study was to estimate the roe deer population density in 2012 and the species population dynamic since the time when studies on the population started. The result indicates a population size of 850 roe deer in 2012. There was no significant population dynamic, which may be due to insufficient data. The population occurs basically over the whole island but have not yet been established in all suitable areas.

Påverkas mosippa (Pulsatilla vernalis) negativt av igenväxning?

Pulsatilla vernalis is one of several endangered plant species that benefit from wildfires and small scale disturbance events that repel competing vegetation and create open patches in the vegetation cover. Previous studies argue that Pulsatilla vernalis is decreasing in numbers due to vegetation changes associated with the decrease in wildfires, forest grazing and changes in forest management. In this study, 17 populations of P. vernalis were inventoried in order to examine if soil and/or vegetation structures affect the population structure of P. vernalis (i.e.

Kvantitativ studie om knappsatsdesign och knappstorlekars påverkan på träffsäkerhet

A mobile testing application using Unity was developed to analyse what impact button sizes and button layouts has on the accuracy of touch as well as the time to finish a labyrinth. This was tested on a Nexus 4 phone. 28 users navigated a small object through a labyrinth in which they collect keys to open the door to the exit. Each participant did the test 6 times with different combinations of button size and button layout each time, done in a random order. Hits, misses, completion time, order of button size and order of button layout was collected and then visualized using R.

Population and management models for the Swedish wild boar (Sus scrofa)

The wild boar Sus scrofa population in Sweden has increased rapidly in the last decades which has led to conflicts among stakeholders, for example due to crop damages in agriculture. Thus, there is an urgent need of quantified goals and effective strategies for wild boar management. To develop such strategies, knowledge on population dynamics is fundamental. In this study a deterministic matrix model was used to estimate population growth, based on previously published data. The exponential growth rate for a wild boar population was calculated to 1.48.

Kommunernas dolda pensionsskuld

Background: In 1998 it was stated that Swedish municipalities would report the pension liabilities according to the mixed model where the pension liabilities before 1998 was moved from the balance sheet. The mixed model has been criticized by economists for not showing the total pension liabilities. To remove some of the liabilities in the municipalities balance sheets means that the solvency improves. Some municipalities have decided to go against the municipal accounting law and recognize all of the pension liability as a liability according to the full funding model. When two accounting models are being used the comparison of the municipalities' financial statements is much harder.Purpose: The main purpose of this study was to study the reason why some municipalities apply full funding model rather than the mixed model.

Stjälkröksvamp (Tulostoma brumale) : stora eller små individer?

The spatial population structure of the saprotrophic basidiomycete Tulostoma brumale was investigated at a site in south eastern Sweden. Sporocarps were mapped and collected, and somatic incompatibility tests between mycelial cultures cultivated from the sporocarps were used to identify genets. Calculations of the size and numbers of genets and their distribution were performed. The spatial distribution of the tested sporocarps and the identified genets are presented graphically in a grid. The total number of identified genets within the investigated area (1210 m2) was 27 based on 48 tested sporocarps.

Trefaktorsmodellen : Undersökning på svenska börsnoterade aktiebolag

Previous work by researchers as Eugene F. Fama and Kenneth R. French, show that average return on stocks are related to a firms characteristics like size and book-to-market ratio. These kinds of patterns in average return is not explained by The Capital Asset Pricing Model (CAPM), and are therefore seen as anomalies. Fama and French have proposed a three-factor model, which captures patterns observed in U.S average returns associated with size and value.

Analysmodellen - en variation i tillämpningen?

The purpose of our essay is to examine if variation exists in the way that auditors try their independence, this so called analysis-model. We will suggest some factors that influence the way auditors practise the analysis-model. The institutional theory predicts no differencies since the normative pressure could be expected to be severe. But we found that among other things people?s qualifications, personalities and audit firm?s size and age influence the way auditors try their independence.

Konkursprognostisering : Tillämpning av en konkursprognosisteringsmodell på små svenska aktiebolag

Bankruptcy is a problem for the society in form of high costs for including suppliers, customers, employees, investors, banks, insurance companies etc. The purpose of this study is to confirm or dismiss a bankruptcy prediction model that has been developed in a previous Swedish study, in order to predict bankruptcy with help of specific key figures. The model has only been tested in a larger perspective where the population consisted of all small firms in Sweden, in this study the model´s reliability is tested by that it instead been applied to a minor perspective, where the population only includes Stockholm. With a quantitative approach of 12 different key figures from a total of 60 Swedish smaller registered companies in Stockholm between the years 2005-2007, has been studied. The companies are divided into two groups, companies with good financial health and companies that have ended up in bankruptcy.The results shows that the model is applicable in a smaller population, but some of the key figures do not generate essential or any type of information about bankruptcy, but the majority of the key figures in the model did.

Hur livshistoriekaraktärer hos Europeisk abborre (Perca fluviatilis L.) påverkas av cykliska förändringar i populationsstrukturen

This report deals with life-history variation for Eurasian perch (Perca fluviatilis L.), with special emphasis on age and size at maturity in females, in perch populations that have changed in size distribution. The collection of fish samples was made with multimesh gill nets year 2011. The perch?s length, height, weight, status of gonads has been analyzed, and by observing the opercular bone the age has been determined. In two lakes close to Umeå in northern Sweden, Fisksjön and Ängersjön, the live-history traits of perch have been studied.

Populationsstruktur och genetisk analys av exteriöra egenskaper hos svensk ardenner :

The purposes of this study were to estimate genetic and phenotypic parameters for conformation traits in Swedish Ardenner, a heavy draught horse, and to investigate the inbreeding status of the population. Additionally, a breeding scheme proposal was created, based on the results achieved in the study. The data studied were obtained from the Swedish Horse Board and from the Swedish Ardenner Association. The data included 1632 three-year-old horses, mainly mares, and 356 stallions, judged between 1986 and 2005 at conformation shows. The traits studied were type, head-neck-body, legs, walk and trot at hand, total score and height at withers.

Grey-sided vole and bank vole abundance in old-growth forest patches of different size and connectivity

Vole populations in northern Scandinavia vary in cycles with peaks every third or fourth year as described by the National Environmental Monitoring Programme of small mammals (NEMP). Some vole species have declined in population numbers since the NEMP started in 1971, especially the grey-sided vole (Myodes rufocanus) which is nearly extinct in the forested region. Since small mammals are an important food source for several avian and mammalian predators, the decline in vole numbers is expected to have consequences for the whole food chain, especially if other vole species start to decline in numbers. This study tried to test the hypothesis that presence and abundance of M. rufocanus (a specialist species) and Myodes glareolus (a generalist species) can be predicted by patch size and connectivity of forest patches >60 years old with a minimum of 15% pine >100years old.

Kreatörers försörjning - En modell för värdeutbyten i de kreativa näringarna

That many creative workers have uncertain and uneven incomes is well-established, but how or why they make a living is not. This paper examines the elusive value exchanges between creatives, buyers, consumers, and other economic supporters, and offers a model of how creatives make a living. By mapping income statistics of Swedish creatives together with in-depth interviews some patterns emerge. This, combined with Bourdieu's theories of social, cultural and symbolic capital, and Knorr's objects of sociality, forms a basis for a structured model of value exchange. The paper shows how creative workers create economic and non-economic capital (capitalization), how they advertise this capital (signaling), and how they convert between different types of capital (conversion) in order to make a living.

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