445 research outputs found
How SRI Affect Valuation Multiples and Portfolio Management
In this paper, we investigate conventional mutual fundsâ and socially responsible investment (SRI) fundsâ compositions of high and low valuation multiple stocks as well as potential differences in portfolio management between the two types of funds. Previous research has to a large extent focused on risk-adjusted stock returns and has not been able to be conclusive on whether SRI funds under- or outperform conventional mutual funds. We believe that our research can help to understand why previous research not have been conclusive and show that it is important to analyse investment styles when analysing fundsâ performance. We analyse the Swedish asset management market during 2008 to 2012 and our dataset consists of 15 conventional mutual funds and 13 SRI funds. We find significant differences where SRI funds invest in stocks with higher valuation multiples, i.e. less risky stocks, than conventional mutual funds. However, this difference is not explained by differences in valuation of socially responsible stocks but by that the portfolio managers of SRI funds invest differently in comparison to portfolio managers of conventional mutual funds
Effects of in-utero influenza exposure on later life outcomes: Evidence from 19th century Scania
In this thesis the impact of in-utero influenza exposure on socioeconomic status and survival in adult life is studied. The data used is a subset of a longitudinal level database for Scania for 1815 to 1910. In this thesis the outbreak of influenza pandemic in 1833 is used as a natural experiment. The pathway model used in this thesis allows for both direct effect on the survival form the in-utero influenza exposure and indirect effects mediated through socioeconomic status in adult life for the individual. The analysis is done separately for women and men, and support for âFetal origins hypothesisâ as a negative effect on survival in later life is found for both sexes
The effect of conditions in early life on health in adult life: A study of 19th century Scania
In this thesis the impact of conditions in early life on survival in adult life is studied. This is done for longitudinal level data from Scania for 1815 to 1910 and conditions in early life are measured by infant mortality rate. In the thesis a model that allows for both direct effect on the survival form the infant mortality rate and indirect effects mediated through socioeconomic status and marriage is presented. The analysis is done separately for women and men, and support for âFetal origins hypothesisâ is found for both sexes. Furthermore, also a counter effect mediated through socioeconomic status is found both for men and women. This counter effect support the theory of survival of the strongest individuals during bad early life conditions
Analys av sambandet mellan en skogsfastighets förmÄga att generera avkastning och dess lÀge i landet
The market price of a forest property rarely corresponds with the forest propertyâs return value. This discrepancy is usually being explained by what is called non-monetary values. By that means values that doesnât generate returns in money, for example pride of ownership. A forest propertyâs ability to generate returns is related to several factors that are highly correlated with latitude, such as site fertility, average price of forest estates etc.
The purpose of this study was to analyse the relationship between a forest propertyâs ability to generate returns and its location in the country. This by creating average forest properties for every county and perform different calculations to make them comparable to each other. The results show that a forest propertyâs ability to generate returns doesnât easily can be explained by the latitude. However, some patterns can be identified
Cell segmentation of in situ transcriptomics data using signed graph partitioning
The locations of different mRNA molecules can be revealed by multiplexed in
situ RNA detection. By assigning detected mRNA molecules to individual cells,
it is possible to identify many different cell types in parallel. This in turn
enables investigation of the spatial cellular architecture in tissue, which is
crucial for furthering our understanding of biological processes and diseases.
However, cell typing typically depends on the segmentation of cell nuclei,
which is often done based on images of a DNA stain, such as DAPI. Limiting cell
definition to a nuclear stain makes it fundamentally difficult to determine
accurate cell borders, and thereby also difficult to assign mRNA molecules to
the correct cell. As such, we have developed a computational tool that segments
cells solely based on the local composition of mRNA molecules. First, a small
neural network is trained to compute attractive and repulsive edges between
pairs of mRNA molecules. The signed graph is then partitioned by a mutex
watershed into components corresponding to different cells. We evaluated our
method on two publicly available datasets and compared it against the current
state-of-the-art and older baselines. We conclude that combining neural
networks with combinatorial optimization is a promising approach for cell
segmentation of in situ transcriptomics data.Comment: Accepted at GbRPR 2023: Graph-Based Representations in Pattern
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C & N upptag i nya mellangrödor
Det finns mÄnga olika anledningar till varför man vÀljer att sÄ mellangrödor. I detta försök har vi valt att fokusera pÄ sjÀlva mellangrödan och inte pÄ anvÀndningsomrÄdet. Försöket gÄr ut pÄ att undersöka kol- och kvÀvehalten i oljerÀttika och matrÀttika (Strukturator). Definitionen pÄ en mellangröda Àr nÄgot som man odlar mellan tvÄ huvudgrödor. MÄlet med att odla en mellangröda Àr bland annat att rötterna snabbt ska kunna ta sig ner i marken för att fÄ en luckrande effekt och ta upp överbliven vÀxtnÀring sÄ det inte lackas ut. Det finns mÄnga olika sorters mellangrödor. OljerÀttika och matrÀttika, som anvÀnds i detta försök, har en stor pÄlrot som gÄr djupare ner i jorden Àn andra mellangrödor.
I detta försök anvÀnds en speciell rotprovtagare för att kunna fÄ upp rötterna ur marken i olika skikt. Sedan tvÀttades rötterna med hjÀlp av en sikt för att urskilja jord och smuts. Rötterna och den ovanjordiska biomassan torkades ner och det gjordes en vÀgning av ts-vikten samt analys av kol, kvÀve och askhalten.
För att fÄ en bÀttre insikt i mellangrödorna har vi valt flertalet olika parametrar att ta fram resultat pÄ, allt för att fÄ en helhet i resultatet. Vi har dels rÀknat pÄ hur hög rotbiomassan Àr per planta, dels kring rotbiomassan per hektar i de olika leden, kvÀvehalt per planta samt rÀknat pÄ kvÀvemÀngden per hektar. Den ovanjordiska biomassan har summerats och kvÀvehalten har bestÀmts. Dessutom har C:N-kvoten rÀknats ut för varje led i försöket sÄ att det gÄr att avgöra hur lÀtt kvÀvet frigörs frÄn mellangrödan och nÀr det dÄ blir tillgÀngligt för nÀstkommande gröda.
Med tanke pÄ att det varit sÄ mÄnga delmoment i försöket hela vÀgen frÄn arbetet i fÀlt, med provtagning, fram till analysering av kol- och kvÀvehalt finns det mÄnga eventuella felkÀllor. FelkÀllorna har undvikts i största möjliga mÄn och dÀr det inte gÄtt att undvika att en felkÀlla kan uppstÄ har felkÀllan endast accepterats ifall den har varit likvÀrdig för alla leden i försöket. Med alla resultat framstÀllda valdes parametern kg N/ha, som den mest relevanta och intressanta att redovisa. I försöket har de olika leden haft olika förutsÀttningar vilket lett till att det inte rÀttvist gÄr att jÀmföra leden mot varandra utan att vÀga in förutsÀttningarna. Dock har tvÄ led haft likvÀrdiga förutsÀttningar och dÀrför har dessa tvÄ led varit intressanta att göra en jÀmförelse mellan. Slutsatsen i jÀmförelsen mellan led med, Strukturator, och led med, oljerÀttika, Àr att strukturatorn har haft ett effektivare kvÀveupptag och innehÄller dÀrför en högre mÀngd kvÀve, bÄde per planta och per hektar.There are many different reasons why farmers choose to use cover crops. In this experiment, we have chosen to focus on the cover crop itself and not the motives for growing it. The aim of this experiment is to investigate the carbon and nitrogen content of oil radish and forage radish (Structurator). The definition of a cover crop is a crop that grows between two main crops. The goal of growing a cover crop is to get the roots into the ground quickly, stimulate fertility and take up excess nutrients. There are many different kinds of cover crops, which could be used in this attempt. Oil radish and forage radish (Structurator) was used as they have a large taproot that goes deeper into the soil than other cover crops. They are sensitive to cold, at 4-6 degrees below zero they die and can be processed down without treatment.
In this experiment, a special root sampling device was used to get the roots up from the soil in different layers. Then the roots were washed using a sieve to separate soil and dirt. The roots were dried and a measurement was taken of dry weight and an analysis of carbon, nitrogen and ash content was performed. The biomass above ground was dried and analysis of carbon and nitrogen was performed.
To get a better insight into cover crops, we have chosen several different parameters to produce results from. This was to get a complete overview and to avoid confounding results. We have calculated the root biomass and nitrogen content per plant and estimated the result per hectare. The biomass above ground was used to determine the nitrogen content. In addition, the C:N ratio has been calculated for each stage of the experiment so that it is possible to determine how easily the nitrogen is released from the cover crop and when it becomes available for the next crop. Since we have used several different parameters, there are multiple results, which can be examined more carefully inside this paper.
Given that there have been so many elements of the experiment; all the way from work in the field, with sampling, until analysing the carbon and nitrogen content, there are many potential sources of error. These have been avoided as much as possible and only accepted where they are impossible to avoid and have been similar for all treatments of the experiment. A more detailed explanation of the sources of error is given in the discussion. With all the results obtained the parameter selected as the most relevant and interesting to report is kg N / ha, kilograms of nitrogen per hectare. The parameters are discussed and compared in more detail in the conclusion. In the experiment, the different samples had different conditions, which led to it being unreasonable to compare them against each other without considering the conditions. However two treatments, 2 and 3, had similar prerequisites and therefore have been interesting to make a comparison between. The conclusion of the comparison between treatment 2 (forage radish) and treatment 3 (oil radish) is that the forage radish had a higher efficiency of nitrogen uptake and therefore contains a higher amount of nitrogen, both per plant and per hectare
Detecting ditches using supervised learning on high-resolution digital elevation models
Drained wetlands can constitute a large source of greenhouse gas emissions, but the drainage networks in these wetlands are largely unmapped, and better maps are needed to aid in forest production and to better understand the climate consequences. We develop a method for detecting ditches in high resolution digital elevation models derived from LiDAR scans. Thresholding methods using digital terrain indices can be used to detect ditches. However, a single threshold generally does not capture the variability in the landscape, and generates many false positives and negatives. We hypothesise that, by combining the digital terrain indices using supervised learning, we can improve ditch detection at a landscape-scale. In addition to digital terrain indices, additional features are generated by transforming the data to include neighbouring cells for better ditch predictions. A Random Forests classifier is used to locate the ditches, and its probability output is processed to remove noise, and binarised to produce the final ditch prediction. The confidence interval for the Cohenâs Kappa index ranges [0.655 , 0.781] between the evaluation plots with a confidence level of 95%. The study demonstrates that combining information from a suite of digital terrain indices using machine learning provides an effective technique for automatic ditch detection at a landscape-scale, aiding in both practical forest management and in combatting climate change
The value of bees for Swedish crop farming
Denna studie analyserar olika odlingsstrategier för raps i Sverige. Det ekonomiska vĂ€rdet av bin som pollinatörer i rapsodlingar utvĂ€rderas och linjesorter jĂ€mförs med hybridsorter. Konsekvenserna av ett neonikotinoidförbud i Sverige utvĂ€rderas tillsammans med de ekonomiska konsekvenserna som följer utav denna restriktion. Data anvĂ€nds frĂ„n tidigare fĂ€ltförsök. Problemet analyseras med hjĂ€lp av en matematisk optimeringsmodell och Lagrangeâs funktion utvĂ€rderar för optimala lösningar. Resultaten visar att kontrakt mellan biodlare och vĂ€xtodlare Ă€r en viktig faktor vid beslut rörande val mellan linjesorter och hybrider. Odling av traditionella linjesorter visar sig vara ett bĂ€ttre alternativ beroende pĂ„ geografiskt omrĂ„de och klimat. I omrĂ„den med strĂ€ngare vintrar Ă€r hybrider viktiga för att möjliggöra en vĂ€l fungerande vĂ€xtföljd. Neonikotinoidförbudet visar sig enbart pĂ„verka ett begrĂ€nsat geografiskt omrĂ„de dĂ€r skadeinsekter Ă€r sĂ€rskilt problematiska. I dessa omrĂ„den finns ingen enkel teknik för att odla raps givet dessa restriktioner. De ekonomiska effekterna Ă€r betydande och problem med monokultur, vĂ€xtsjukdomar och skadeinsekter riskera att bli kostsamma i ett lĂ€ngre perspektiv.This study examines production strategies for rape seed in Sweden. The value of bees as pollinators is evaluated for commercial crop farming and traditional varieties are compared to hybrids. The effects of a neonicotinoid-ban in Sweden is examined together with the economic implications associated with such restriction. Data are used from previous field studies. The composed data are used for mathematical optimization calculations. It is investigated using the Lagrange function in search for the optimum solution. It was revealed that the contract between beekeeper and producer is an important factor in the decision to use traditional varieties compared to hybrids. The use of traditional varieties is a better choice than hybrids depending on the location and climate. In areas with less favorable climate, hybrid varieties aid to improve crop rotation. The neonicotinoid-ban was found to only affect limited areas of Sweden where pest insects are especially problematic. In those areas there was no easy way to grow rape seed under such restriction. The economical short term effect is proven to be significant and the long term problems with monoculture is a risk
Exotic tree species in urban environments : advantages, disadvantages and risks associated with the use of exotic plant material in urban environments
The design of our outdoor environments is today an important part of a functioning city. The cities are growing more densely and the green areas are getting smaller. This means that the presence of vegetation and especially trees in urban environments is of great importance. Trees are an important part in the city and contribute with a number of different positive effects. To create a sustainable future for Sweden's urban tree population, an expanded and adapted plant material is required.
The purpose of the study is to investigate the advantages, disadvantages and risks associated with use of exotic tree species in urban environments and examine 22 Swedish municipalities and their attitude towards the use of exotic tree species. The study partly includes a literature study and partly a questionnaire survey. The literature study describes the role of trees in the city and how art diversity is a major component for creating resilient tree populations. The use of exotic tree species extends the use and serves as a complement to the domestic plant material. The city as a plant site is challenging, but many exotic tree species originate from areas that resemble the dry and warm conditions of the city and are therefore well suited as city trees. However, the use of exotic plant material is associated with risks, but most introduced species, have low, or even no risk if used under the right conditions.
The survey includes 22 Swedish municipalities. Five questions were sent to each municipality to find out their attitude towards the use of exotic species, if species diversity is prioritized, the use of untested introduced species and if climate change are considered when selecting tree species. Furthermore, the responses of the participating municipalities are summarized and discussed. Finally, the advantages and disadvantages of the use of exotic tree species are discussed. There are both risks of using and excluding exotic tree species. Exotic tree species in combination with domestic species create better conditions for adapting tree species in urban environments, contributing to a greater choice when designing outdoor environments and contributing to a greater variety of species. Which creates sustainable and resilient urban tree forests.Utformningen av vÄra utemiljöer Àr idag en viktig del för en fungerande stad. StÀderna vÀxer sig tÀtare och grönomrÄden blir fÀrre. Detta gör att förekomsten av vegetation och i synnerhet trÀd i urbana miljöer Àr av mycket stor vikt. TrÀd Àr en viktig byggsten i staden och bidrar med en rad olika positiva effekter. För att skapa en hÄllbar framtid för Sveriges urbana trÀdbestÄnd krÀvs ett utökat och anpassat vÀxtmaterial.
Syftet med studien Àr att undersöka fördelar, nackdelar samt risker förenade med anvÀndning av exotiska trÀdarter i urbana miljöer samt undersöka 22 svenska kommuners instÀllning till anvÀndandet av exotiska trÀdarter. Studien innehÄller delvis en litteraturstudie och delvis en enkÀtundersökning. I litteraturstudien beskrivs trÀdens roll i staden och hur artdiversitet Àr en huvudkomponent för att skapa motstÄndskraftiga trÀdbestÄnd. AnvÀndningen av exotiska trÀdarter utökar utbudet och fungerar som ett komplement till det inhemska vÀxtmaterialet. Staden som vÀxtplats Àr utmanande och mÄnga exotiska trÀdarter hÀrstammar frÄn ursprungsomrÄden som liknar stadens torra och varma förhÄllanden och lÀmpar sig dÀrför bra som stadstrÀd. AnvÀndningen av exotiskt vÀxtmaterial Àr dock förenat med risker men de flesta introducerade arter utgör dock en lÄg, eller till och med ingen risk om de anvÀnds under rÀtt förutsÀttningar.
EnkÀtundersökningen omfattar 22 svenska kommuner. Fem stycken frÄgor skickades ut till respektive kommun för att fÄ reda pÄ deras instÀllning till anvÀndandet av exotiska arter, om artdiversitet prioriteras, vad som krÀvs för att vÀlja obeprövade trÀdarter och om förÀndringar i klimatet finns med i berÀkningar vid val av art. Vidare summeras och diskuteras de deltagande kommunernas svar. Slutligen diskuteras för- och nackdelar med anvÀndningen av exotiska trÀdarter. Det finns bÄde risker med att anvÀnda och utesluta exotiska trÀdarter. Exotiska trÀdarter i kombination med inhemska arter skapar bÀttre förutsÀttningar att anpassa trÀdart efter stÄndort, bidrar till en större valmöjlighet vid utformning av utemiljöer och leder till en större artrikedom. Vilket i sin tur skapar hÄllbara och motstÄndskraftiga urbana trÀdbestÄnd
Effektivisering vid anvÀndandet av totalentreprenad inom jÀrnvÀg
Trafikverkets beslut om ett ökat anvÀndande av totalentreprenader och myndighetens egen utveckling mot en ren bestÀllarroll har inneburit förÀndringar för branschen. En för branschen obeprövad entreprenadform har snabbt introducerats pÄ marknaden och medfört möjligheter men Àven problem. Rapporten behandlar de största och mest betydande skillnaderna i förfrÄgningsunderlaget och allmÀnna bestÀmmelser mellan totalentreprenad och utförandeentreprenad. I en studie belyser vi Àven hur parternas instÀllning Àr till totalentreprenad och var effektivisering av entreprenadformen behövs för att bÀttre anpassas till en styrd jÀrnvÀgsbransch. Efter litteraturstudier bildades en uppfattning om hur totalentreprenad fungerar och vilka för- och nackdelar som finns med totalentreprenad jÀmfört med utförandeentreprenad. Genom intervjuer av personer med erfarenhet av totalentreprenader kunde vi ta del av branschens syn pÄ entreprenadformen. För att förstÄ svÄrigheterna med funktionsbeskrivningar har rapporten Àven innefattat praktisk upprÀttande av funktionsbeskrivningar. JÀrnvÀgsbranschens regelverk och rutiner Àr i dagslÀget inte anpassade för ett effektivt anvÀndande av totalentreprenad. En viktig del Àr utvecklingen av funktionskrav vid uppförandet av funktionsbeskrivningar vid jÀrnvÀgsprojekt. Vidare Àr framtagandet av kontrollmetoder som blir praxis för branschen av det yttersta avgörande för anvÀndandet av funktioner ska fungera. Kontrollmetoder som inte bara kontrollerar funktioner efter entreprenadtiden utan under hela jÀrnvÀgens livslÀngd. Detta för att ge förvaltaren en bÀttre uppfattning om investeringarnas vÀrde
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