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Synthetic Preparation of the Lipophilic Fragment of Okeaniamide A
Full text linkOkeaniamide A is a natural product that can be used as a potential therapeutic agent for type 2 diabetes mellitus (T2DM), a metabolic disease characterized by elevated blood glucose levels. If left untreated, the condition may result in long-term complications, such as heart and kidney disorders. Preadipocytes, immature cells that differentiate into adipocytes, influence fat storage and energy metabolism, all of which are processes that are crucial for the regulation of T2DM. This differentiation may be regulated by the administration of okeaniamide A, which could improve insulin sensitivity and reduce the negative effects of fat tissue on the disease. The aim of this study was to develop a robust, efficient, and stereoselective synthetic route for the lipophilic fragment of okeaniamide A.
The synthetic route began with an aliphatic ketone that underwent a Horner-Wadsworth-Emmons reaction, followed by diisobutylaluminum hydride (DIBAL-H) reduction, resulting in an allylic alcohol. However, these steps gave low yields of the purified product owing to the formation of E/Z isomer mixtures and purification challenges. To improve the overall efficiency of the synthesis, zirconium-catalyzed carbometallation from a terminal alkyne was explored as an alternative strategy, which proved to be successful. This reaction directly yielded the desired E isomer and eliminated the need for isomer separation. The resulting allylic alcohol was subsequently oxidized to an aldehyde, which was then converted to an acetal using a protocol developed in the Corey laboratory. The next step in the synthesis was an Urpí acetate aldol reaction followed by a second DIBAL-H reduction; however, at this stage, an elimination side reactions occurred, which complicated the purification process. A Grignard reaction was performed to introduce a vinyl group, followed by a Johnson-Claisen [3,3]-sigmatropic rearrangement to form an ester. The final step of the synthesis involved hydrolysis to produce the target carboxylic acid. In summary, a stereoselective synthetic route toward the lipophilic fragment of okeaniamide A was successfully established. This work lays the foundation for the future synthesis of the full molecule and further biological evaluation of its therapeutic potential, which in the long term may bring us one step closer to an effective treatment of T2DM
Bruk av kommunikasjon for å fremme miljøvennlig atferd : besøksforvaltning i nasjonalparker
No full textThe primary aim of this thesis is to examine how communication in national parks can foster pro-environmental behavioral change among visitors. Activities like nature-based tourism and outdoor recreation offer valuable experiences, but they also have impacts on natural environments including conservation values. In national parks, managing these impacts has often involved restrictive measures, such as restricting access. However, engaging visitors through communication offers a less invasive and more empowering approach to reduce harm to conservation values. In conservation, communication is used to raise awareness, influence human behavior, and encourage action, with nature interpretation playing a central role in fostering connections to nature. Although research has shown that interpretive programs can foster pro-environmental attitudes and norms, less attention has been given to how visitors understand their own behavior and its impacts within national parks. This thesis contributes to filling this gap by focusing on interpretation that highlights the meanings of places, their conservation values, and enriches visitors' understanding.
The thesis is a compilation thesis consisting of a synopsis summarizing the research, along with five research article manuscripts. It contributes to better understanding of visitor behavior that negatively affects nature and tailoring effective communication strategies by exploring existing literature on communication to change behavior in outdoor recreation (Paper 1 and 2). Femundsmarka National Park in Norway is the study area in this thesis, exploring both a conservation area and a wilderness-like context. The thesis investigates how social media shapes peoples’ sense of place in Femundsmarka and how these perceptions can inform visitor management strategies (Paper 3). It specifically examines littering behavior and waste management (Paper 4), tree damage and campfire behavior (Paper 5), and tests different messages and modes of communication using field experiments in both studies. By exploring human-nature relations, it aims to uncover new approaches to fostering pro-environmental behavior through communication, focusing on human actions that strengthen positive relations with nature.
The research employs an interdisciplinary approach, integrating both social and natural sciences, to address the complexity of human impacts on the environment. A triangulation framework is used to combine different research methods, theories and knowledge offering a comprehensive understanding of conservation challenges in question. The research combines various methods, including on-site visitor questionnaires, interviews, observational data, environmental surveys conducted in Femundsmarka. In addition, off-site interpretive analysis of Instagram images from the study area was conducted. Data was analyzed and used in workshops with local stakeholders to uncover different ways of knowing and to jointly inform management strategies.
The field experiments in this thesis address the urgent need to explore the causal relationships between communication, pro-environmental behavior and environmental conditions. By mapping various prerequisites for pro-environmental behavior within Femundsmarka National Park, the research considered cultural, social, and ecological factors specific to the protected area. Guided by communication and behavior change theories, as well as a relational approach to human-nature interactions, the studies tested both passive and active communication strategies, assessing how different messages could promote more pro-environmental behaviors in nature-based tourism.
The thesis results underline that communication strategies can effectively influence visitors’ behavior. For desired behaviors with established norms, such as not littering, simple signs can serve as reminders. However, for undesired behaviors rooted in strong sociocultural traditions, like campfires, more intensive efforts are needed. The findings emphasize how different aspects of human-nature interactions, including emotional bonds, sensory experiences, the status of Femundsmarka as a protected area, and its wilderness qualities, shape relational dynamics. These dynamics influence visitor behavior, and by highlighting already established connections that foster care, responsibility, and a sense of connection; while suppressing disconnection, alienation, and human superiority, communication can resonate more deeply with visitors, making it more meaningful.
The thesis highlights the need to understand how human behavior and communication impact a place, and how the place, in turn, influences behavior and communication. Visitors may perceive their impact as minimal or resist restrictions on their freedom. In Nordic countries, this tendency can be more pronounced due to public rights of access and relatively low visitor numbers in national parks. The results also emphasize the role of social media in shaping visitors’ pre-existing relations with national parks. If a visitor arrives at a place with a strong attachment to it, these feelings are likely to influence how they approach their visit and how they seek out, interpret, and respond to information. The findings underscore the importance of collaborating with management and local stakeholders to develop practical and effective solutions, highlighting that well-designed communication strategies have significant potential to enhance pro-environmental behavior.
Empirical results highlight the need for context-specific, tailored communication and behavior change strategies. Effective messaging requires careful attention to timing, placement, and clarity, as poor delivery can result in confusion or alienation. The findings suggest that understanding the emotional and social dimensions of human-nature interactions is crucial for effective conservation management. This thesis contributes to the growing field of conservation science by proposing alternative, more engaging communication approaches that foster curiosity, responsibility, and a stronger response to environmental challenges.Hovedmålet med denne avhandlingen var å undersøke hvordan kommunikasjon i nasjonalparker kan inspirere til miljøvennlig atferd blant besøkende. Naturbasert turisme og friluftsliv gir verdifulle naturopplevelser, men påvirker også naturmiljøet. I nasjonalparker internasjonalt har håndtering av disse påvirkningene ofte involvert restriktive tiltak, som å begrense tilgang. Å bruke kommunikasjon for å engasjere besøkende tilbyr derimot en mindre inngripende tilnærming for å redusere negative virkninger. I besøksforvaltning i nasjonalparker brukes kommunikasjon og naturveiledning for å øke bevissthet og kunnskap og påvirke besøkendes atferd i miljøvennlig retning. Selv om forskning har vist at naturveiledning kan fremme miljøvennlige holdninger og normer, har det vært mindre fokus på hvordan det kan endre deres atferd. Denne avhandlingen bidrar til å øke denne forståelsen ved å fokusere på formidling som fremhever stedets betydning, naturverdier, og gi økt forståelse for vernet.
Avhandlingen er artikkelbasert og består av fem artikkelmanuskripter og en kappe som oppsummerer forskningen. Den bidrar til forståelsen av besøkendes atferd som negativt kan påvirke natur og hvordan effektive kommunikasjonstiltak kan skreddersys. Dette gjør avhandlingen ved å gjennomgå eksisterende litteratur som omhandler bruk av kommunikasjon for å endre atferd i friluftslivssammenhenger (Artikkel 1 og 2). Femundsmarka nasjonalpark i Norge er det empiriske studieområdet i avhandlingen, hvor både det at området er vernet og er villmarkspreget utforskes. Avhandlingen undersøker også hvordan sosiale medier er med på å forme ulike assosiasjoner til Femundsmarka, og hvordan disse oppfatningene kan informere besøksforvaltning (Artikkel 3). Den undersøker videre hvordan forsøplingsatferd og avfallshåndtering (Artikkel 4), skader på trær og bålbrenning (Artikkel 5) kan endres ved å teste ulike budskap og kommunikasjonsformer gjennom felteksperimenter. Ved å utforske menneske-natur-relasjoner, søker avhandlingen å avdekke nye tilnærminger for å fremme miljøvennlig atferd gjennom kommunikasjon ved å fokusere på menneskelige atferder som styrker positive relasjoner til naturen.
Forskningen er tverrfaglig og integrerer både samfunns- og naturvitenskap for å adressere kompleksiteten i menneskelige påvirkninger på miljøet. Et trianguleringsrammeverk brukes for å kombinere ulike forskningsmetoder, teorier og kunnskap for å gi en mer helhetlig forståelse av utfordringer knyttet til besøksforvaltning og naturvern. Forskningsmetodene omfatter spørreundersøkelser og intervjuer av besøkende, observasjonsdata og miljøundersøkelser knyttet til leirplasser i Femundsmarka, og fortolkende analyse av Instagram-bilder som del av nasjonalparkens digitale uttrykk. Slike data ble analysert og også brukt i workshops med lokale aktører for å utveksle ulik kunnskap og diskutere forvaltningstiltak.
Felteksperimentene utforsker årsakssammenhenger mellom kommunikasjon, atferd og miljøtilstand i nasjonalparker, ved å undersøke faktisk atferdsendring på stedet, og hva dette medfører for miljøet. Veiledet av kommunikasjon- og atferdsteorier kombinert med relasjonelle tilnærminger til menneske-natur-interaksjoner ble kulturelle, sosiale og økologiske faktorer som er spesifikke for Femundsmarka kartlagt. Både passive og aktive kommunikasjonstiltak og ulike budskap ble testet for å kunne forstå mer om hva som fremmer miljøvennlig atferd i naturbasert turisme.
Resultatene viser at kommunikasjonstiltak effektivt kan påvirke besøkendes atferd. For ønsket atferd med etablerte normer, som å ikke forsøple, kan enkle skilt fungere godt som påminnelser. For uønsket atferd forankret i sterkere sosiokulturelle tradisjoner og som anses som verdifulle for naturopplevelsen, som å ha et leirbål, er det imidlertid behov for mer omfattende og målrettede tiltak. Funnene viser hvordan ulike aspekter av interaksjoner mellom mennesker og natur, som sanseopplevelser, Femundsmarkas status som verneområde og dens villmarkskarakter, er med på å forme relasjonene mellom dem. Disse faktorene påvirker besøkendes atferd i nasjonalparken. Ved å fremheve allerede eksisterende interaksjoner som fremmer omsorg, ansvar og tilknytning, samtidig som følelser av utenforskap og fremmedgjøring reduseres, kan kommunikasjonen resonere med besøkende på et dypere nivå, og dermed oppleves som mer meningsfylt
Avhandlingen fremhever behovet for å forstå hvordan menneskelig atferd og kommunikasjon påvirker et sted, og hvordan stedet igjen påvirker atferd og kommunikasjon. Besøkende kan for eksempel oppfatte sin egen påvirkning som minimal eller motsette seg restriksjoner som påvirker følelsen av frihet. I nordiske land kan denne tendensen være mer fremtredende på grunn av allemannsretten og relativt lave besøkstall i mange nasjonalparker. Resultatene påviser også hvordan sosiale medier er med på å forme folks relasjoner til nasjonalparker også uten at en har vært der. Hvis besøkende ankommer et sted med etablerte forventninger og oppfatninger om hvordan et besøk vil være, vil dette sannsynligvis påvirke hvordan de oppfører seg, og hvordan de oppsøker, tolker og reagerer på informasjon som gis. Funnene understreker viktigheten av å samarbeide med forvaltning og lokale aktører for å utvikle praktiske og effektive løsninger, og fremhever at nøye gjennomtenkte og stedstilpassede kommunikasjonstiltak har betydelig potensial for å fremme miljøvennlig atferd.
Effektive budskap krever nøye planlegging av tidspunkt, plassering og tydelighet da dårlig formidling kan føre til forvirring eller fremmedgjøring. Funnene støtter at forståelsen av de emosjonelle og sosiale dimensjonene ved menneske-natur-interaksjoner er avgjørende for effektiv kommunikasjon som tar vare på verneverdier. Denne avhandlingen bidrar til et voksende forskningsfelt som bidrar til kunnskapsbasert besøksforvaltning. Alternative, lokalt tilpassede og mer engasjerende kommunikasjonsmetoder som fremmer nysgjerrighet og ansvar kan gi besøkende en større forståelse for miljøutfordringene.NIN
Crossing the Landscape of Fear – Wild Reindeer Responses to an Emerging Road Barrier in Rondane
Full text linkMenneskeskapte habitatendringer er den største trusselen mot biologisk mangfold, både gjennom ødeleggelse av leveområder og etablering av barrierer som påvirker dyrs bevegelsesmønstre. Villreinen (Rangifer tarandus tarandus) i Norge migrerte opprinnelig fritt mellom store sammenhengende områder, men er i dag fragmentert i mer eller mindre isolerte delpopulasjoner med stasjonære eller semi-migrerende atferdsmønstre. Rondane villreinområde er en av de få fjellområdene som fortsatt har rein av vill genetisk opprinnelse, og har derfor høy bevaringsverdi. I praksis deler imidlertid infrastruktur med tilhørende forstyrrelsesfaktorer Rondane-bestanden inn i fire delpopulasjoner med liten grad av utveksling. Den sommer- og høståpne grusveien Grimsdalsvegen, som går gjennom den nordligste delpopulasjonens utbredelsesområde, har nylig fått oppmerksomhet grunnet risikoen for ytterligere fragmentering og en tilsynelatende økende barriere som hindrer fostringsflokker fra å migrere sørover om sommeren. Det er derfor av stor forvaltningsmessig betydning å vurdere effektene av denne veien, samt implementerte eller planlagte avbøtende tiltak, på reinens migrasjon og arealbruk.
Med posisjonsdata fra 19 voksne simler med GPS-halsbånd i den nordlige delen av Rondane i perioden 2009–2024, vurderte jeg permeabilitets- (barriere-) effektene av Grimsdalsvegen, i lys av trafikkbelastningen på veien. Logistisk regresjon ble brukt for å evaluere variasjon i veiens permeabilitet, både på sesong- og døgnnivå (dagslys og vindretning). Videre ble sesongtrender i tid brukt på hver side av veien undersøkt.
Studien min viser at Grimsdalsvegen er en semipermeabel barriere for simlenes bevegelsesmønster, først og fremst i snøfrie deler av året når veien brukes mye av både lokale og besøkende bilister, syklister og turgåere. Bomveidata indikerer at den totale kjøretøytrafikken økte i løpet av studieperioden. Samtidig minket sannsynligheten for at rein krysser veien i sesongen med åpen vei (men ikke andre årstider), noe som forårsaket en sterk gradvis reduksjon i tid brukt sør for veien om sommeren. Kryssing var preget av lange og retningsbestemte bevegelser, spesielt i høytrafikksesongen, i samsvar med responser på et fryktlandskap. Reinsdyr krysset generelt mot vinden og i dagslys mer enn om natten, og sannsynligheten for kryssing var omtrent dobbelt så høy på dagtid som om natten i sesongen med åpen vei.
Nattestenging av Grimsdalsvegen har blitt testet som et forvaltningstiltak for å tilrettelegge for fostringsflokkers sommermigrasjon sørover, men uten noen åpenbar effekt. Dette kan skyldes tilfeldig fravær av sørlig vind, men også den sterke tendensen til å krysse veien på dagtid. Min studie antyder dermed at midlertidige dagstengninger når det er gunstig vind, eller et fast regime med stengninger deler av dagen, sannsynligvis er mer effektive. Det finnes ingen bevis for at mangel på migrasjon sørover om sommeren påvirker bestandsforhold. Basert på føre-var-prinsipper indikerer imidlertid de negative langsiktige trendene i noen populasjonsparametere (kondisjon og kalv per simle) i Rondane Nord som helhet, parallelt med redusert permeabilitet av veien og områdets økende popularitet som turistmål, et presserende behov for raske avbøtende tiltak for å redusere barriereeffektene av Grimsdalsvegen.Anthropogenic habitat change is the main threat to biodiversity, both in terms of direct loss of living areas and the barriers affecting animal movement patterns. The wild mountain reindeer (Rangifer tarandus tarandus) in Norway originally roamed freely between large seasonal ranges but is today fragmented into more or less isolated subpopulations ranging from sedentary to semi-migratory in their behaviour. The Rondane reindeer area is one of the very few mountain ranges still inhabited by reindeer of wild genetic origin and is therefore of high conservation value. However, in practice, human infrastructure and disturbance divide the Rondane population into four sub-populations with little exchange. The summer-fall open gravel road Grimsdalsvegen across the northern sub-population’s range has recently gained attention regarding risk of further fragmentation and an apparently increasing barrier preventing herds of females and their young to migrate south in summer. It is therefore of large management importance to assess the effects of this road, as well as implemented or planned mitigation measures, on reindeer migration and space use.
With positioning data from 19 adult female reindeer with Global positioning system (GPS) collars in the northern range of Rondane during 2009–2024, I assessed the permeability (barrier) effects of Grimsdalsvegen, in the light of traffic load on the road. Logistic regression was applied to evaluate variation in the road permeability, both at the seasonal and diel level (daylight and wind direction). Furthermore, seasonal trends in time spent on each side of the road were investigated.
My study shows that Grimsdalsvegen is a semi-permeable barrier to female reindeer movement, particularly in the snow-free season when it is used heavily by both local and visiting motorists, cyclists, and pedestrians. Toll road data indicates total vehicle traffic increased during the study period. Accordingly, reindeer crossing probability decreased in the open-road season (but not other seasons), causing a strong gradual decrease in time spent south of the road during summer. Crossing was characterised by long and directional steps, especially in the peak traffic season, in accordance with responses to landscapes of fear. Reindeer generally crossed against the wind and in daylight more than at night, and crossing probability was about twice as high during day as night in the season of open road.
Road closure at night has been tested as conversation mitigation measure for Grimsdalsvegen, to allow southwards summer migration of female-young herds, yet with no apparent effect. This may be due to coincidental lack of southern winds but also the strong tendency of crossing the road at daytime. My study thus suggests that temporary day closures when favourable wind, or a fixed regime of closures parts of the day, are likely more efficient. No evidence exists that lack of migration southwards in summer affects vital rates. However, based on precautionary principles, the negative long-term trends in some population parameters (body condition and calf per female ratio) in northern Rondane as a whole, in parallel with reduced road permeability and the increasing popularity of the area as tourist destination, indicates an urgent need for quick mitigation actions to reduce the barrier effects of Grimsdalsvegen
Differansekontrakters rolle i foreningen av samfunnsøkonomisk effektivitet og risikoavlastning for investorer i havvindsektoren.
Full text linkDet grønne skifte krever rask og omfattende utbygging av fornybar energi. Havvind er utpekt som en nøkkelteknologi i arbeidet med å nå nasjonale og internasjonale klimamål. Samtidig er havvindkapasitet kostnadskrevende å realisere. Investeringer preges av høy kapitalbinding og betydelig inntektsusikkerhet i lys av volatile og uforutsigbare kraftmarkedspriser. Statlig støtte har lenge vært, og er fremdeles, en viktig ressurs for å få investorer til å investere i nye og samfunnsviktige teknologier. Det er derfor ekstra viktig at offentlige støtteordninger finner en gunstig balanse mellom samfunnsøkonomiske og bedriftsøkonomiske interesser.
Med denne masteroppgaven vurderes ulike utforminger av en tosidig differansekontrakt fra fullt garanterte inntekter for investor til ren investeringsstøtte, med utgangspunkt havvindprosjektet i Sørlige Nordsjø II. Analysen bygger på hvordan risikoallokering mellom stat og investor under ulike prisscenarioer (fra lav-, basis- og høyscenario) utvikler seg basert på en trinnvis utforming av differansekontraken. Lønnsomhetsberegninger og samfunnsøkonomiske vurderinger blir også undersøkt. Det legges spesielt vekt på hvordan differansekontraktens utforming påvirker investors kapitalkostnad gjennom endringer i systematisk risiko.
Resultatene viser at graden av risikooverføring fra stat til investor har stor betydning for både prosjektets finansierbarhet og statens økonomiske eksponering. En høy grad av inntektsgaranti gir lav risiko og høy lønnsomhet for investor, men skaper samtidig risiko for overkompensasjon og svekkede markedsinsentiver. Mer markedsnære støtteordninger gir bedre budsjettkontroll og insentiver til samfunnsøkonomisk produksjon, men krever at investor bærer større del av risikoen. Denne balansegangen er vesentlig for å utforme effektive og levedyktige støtteordninger.
Denne masteroppgaven bidrar til bedre forståelse av hvordan differansekontrakter kan struktureres for å håndtere det grunnleggende forholdet mellom samfunnsøkonomisk ressursutnyttelse og investors behov for risikoavlastning. I en tid der tempo og kapitalbehov i det grønne skifte øker, er det avgjørende at støttepolitikken ikke bare utløser investeringer, men også gjennomføres på en måte som ivaretar fellesskapets interesser og langsiktig markedsintegrasjon.The green transition requires a rapid and large-scale deployment of renewable energy. Offshore wind has been identified as a key technology in achieving national and international climate targets. However, developing offshore wind capacity is capital-intensive, and investments are characterized by high capital lock-in and considerable income uncertainty due to volatile and unpredictable electricity market prices. Public support schemes have long been, and continue to be, a crucial enabler for investments in emerging and socially important technologies. It is therefore essential that such schemes are designed to balance societal efficiency with the investor’s need for risk mitigation.
This thesis assesses various designs of a two-sided Contract for Difference (CfD), ranging from fully guaranteed revenues to upfront investment support, using the Sørlige Nordsjø II offshore wind project as a case study. The analysis examines how risk is allocated between the state and the investor under different price scenarios (low, base and high) based on a stepwise CfD design. Profitability calculations and welfare-economic assessments are included, with particular emphasis on how contract structure affects the investor’s cost of capital through changes in systematic risk.
The findings show that the degree of risk transfer from the state to the investor has significant implications for both project bankability and the state's financial exposure. A high degree of income guarantee results in low risk and high profitability for the investor but increases the risk of overcompensation and undermines market-based incentives. More market-oriented support mechanisms improve budget control and preserve incentives for efficient production but require the investor to bear a larger share of the risk. Striking the right balance between these considerations is key to designing effective and sustainable support schemes.
This study contributes to the understanding of how support instruments can be structured to manage the fundamental trade-off between efficient use of public resources and the investor’s need for risk coverage. At a time when the pace and capital needs of the energy transition are accelerating, it is essential that support policies not only trigger investments but do so in a way that serves the public interest and promotes long-term market integration
Urban Green Roofs and Their Potential for Biodiversity -Designing With Mobility in Mind
Full text linkUrbanization often results in a reduction of green spaces, with negative consequences for biodiversity and ecosystem functions. However, studies in urban ecology have shown that urban areas with moderate levels of urbanization or high-quality green spaces can still support substantial biodiversity. This suggests that green roofs have the potential to play a role in mitigating some of the negative ecological consequences of urbanization. Although green roofs typically host fewer species than ground-level green spaces, well-designed green roofs have been shown to support comparable levels of biodiversity and can function as habitats for a wide range of species.
The research for this thesis involved a comprehensive exploration of academic literature related to urban biodiversity and green roofs. A landscape analysis was conducted through field visits and the use of both public and private online resources. Based on insights from the literature and landscape analysis, green roof and network designs were developed to maximize biodiversity potential for specific species groups. The thesis introduces species mobility capacity as a framework for categorizing three distinct target species groups, guiding the design of tailored green roofs and green roof networks. The green roof designs were specifically adapted to the habitat requirements of each mobility group. Each rooftop was evaluated for structural feasibility, alignment with species-specific habitat requirements, and overall ecological potential. Oslo is recognized as a national ecological hotspot, yet parts of the city such as Hovinbyen, have limited green cover due to intense urban development. This thesis examines Hovinbyen and how networks of these biodiverse green roof designs can offer a partial but meaningful response to the ecological challenges posed by urbanization.
The literature review resulted in some specific design insights that were incorporated into the green roof concepts and go beyond conventional best practice guidelines for biodiverse green roofs. While green roof design is highly context-dependent, a few studies indicated optimal heights, distances, and design priorities tailored to each species mobility group, information not typically included in standard green roof guidelines or other readily available sources. The analysis revealed that a substantial number of existing rooftops in the project area could potentially support biodiverse green roofs, and that larger networks of these have potential for significant ecological benefits in Hovinbyen. While real-world testing would be required to confirm its effectiveness, designing green roof habitats based on species mobility groups appears to be a promising strategy for enhancing urban biodiversity. Although practical limitations such as structural constraints, economic costs, public policy, and species-specific knowledge remain, this thesis provides a scalable, ecologically grounded framework for integrating biodiversity into future urban development plans
Monte Carlo Dropout for Uncertainty Estimation
No full textIn many practical applications, predicting uncertainty can be just as crucial as making accurate point predictions. However, models capable of estimating uncertainty often require significant computational resources to train. To address this, Yarin Gal and Zoubin Ghahramani proposed a more efficient approach in their paper Dropout as a Bayesian Approximation: Representing Model Uncertainty in Deep Learning. Their method involves applying dropout at inference time to generate multiple sub-models from the full model. By sampling these sub-models, a distribution of predictions can be obtained, which will provide an estimate of the model's uncertainty.
In this thesis, we have implemented the Monte Carlo dropout (MCD) model for a regression task and compared its performance to two Bayesian approaches: Gaussian Processes and a Bayesian Neural Network. Our experiments focused on tuning the MCD model (e.g., inference dropout rate), comparing its posterior distributions with benchmark models, and assessing its ability to capture true uncertainty.
Our findings indicate that the Monte Carlo dropout (MCD) method fails to accurately learn uncertainty in its posterior predictions. Specifically, our results show that MCD struggles to capture the uncertainty during both extrapolation and interpolation. Sometimes the method even predicts lower uncertainty in these areas than in regions with training data, which is the opposite of our Bayesian benchmark models. While the original paper reported strong performance, our results suggest the method fails in learning the uncertainty. To further explore hyperparameter tuning, we conducted an experiment using hyperparameter optimization software along with the true variation in the loss function, without improving the results
From seed to survival: how biotic interactions shape boreal plant establishment in alpine habitats
Full text linkGlobal warming has been shown to drive range shifts of lowland plant species towards the colder alpine zone. However, the knowledge of the effects of biotic interactions on the colonizers’ establishment success and survival in the alpine, and how biotic interaction effects vary across alpine habitats, is limited. To investigate these effects, a seed sowing experiment of three lowland species was conducted in the four dominant habitat types at Finse, an alpine area in Southern Norway. Seeds were sown in control plots with intact vegetation and in experimentally created gaps where vegetation was removed prior to sowing to eliminate aboveground competition by extant plants. Throughout the following growing season, germination and survival was recorded for all emerged seedlings in the plots. The seedling’s height, number of leaves and leaf length were measured to detect differences in growth and resource allocation. Vegetation analyses were performed to investigate relationships between neighbouring species and the seedlings’ germination, survival and growth traits. Both seed germination and seedling survival were lower in control plots than in gaps. Seed germination followed a gradient in soil-moisture, with highest germination at the wettest end, the snowbed, and lowest at the driest, the leeside. Seedling survival was also highest in the snowbed but lowest on the ridge. No significant differences were detected for leaf lengths, but seedlings were the tallest in meadow, and taller in control plots than in gaps. Seedlings had significantly more leaves in gaps than in intact vegetation. The effect of treatment was reduced in the snowbed for both seedling height and number of leaves. The results indicate that competition is the dominating plant-plant interaction between boreal seedlings establishing in the alpine and the extant alpine species. My findings suggest that alpine plant communities can hinder, or at least slow down, range shifts of boreal species towards higher elevations under current climate by limiting seed germination and survival. Today, the wettest alpine habitats seem more susceptible to invasion, and if climate change leads to increased rainfall, all alpine habitats could become increasingly vulnerable to lowland plant invasions
Canine thromboelastography (TEG) and the establishment of reference intervals at the Small Animal Hospital at NMBU
Full text linkTromboelastografi (TEG) er en analysemetode som gir informasjon om pasientens koagulasjonsstatus, og benyttes i økende grad innen veterinærmedisin. Metoden anvendes ved traumebehandling, pre- og perioperative vurderinger og ved utredning av koagulasjonsforstyrrelser. Analysen forventes å få økt klinisk relevans i fremtiden.
TEG gir en helhetlig vurdering av hemostasen ved å måle aktivitet av koagulasjonsfaktorene, trombocyttantall og -funksjon, fibrinogenkonsentrasjon og -funksjon, trombindannelse samt grad av fibrinolyse. Analysen kan identifisere hvor i koagulasjonskaskaden et avvik oppstår, og er et nyttig verktøy både for diagnostisk vurdering og behandling.
Formålet med denne studien var å etablere referanseintervaller for følgende TEG-parametere: R-tid, K-tid, α-vinkel, maksimal amplitude (MA), LY30 og LY60. Statistisk ble den robuste metoden benyttet sammen med bootstrap-metoden for å beregne referanseintervallene, hvor 22 klinisk friske hunder ble inkludert. Referanseintervallene fra studien ble for R-tid 1,52-7,28min, K-tid 0,64-2,91min, α-vinkel 53,51-76,53°, MA 45,84-67,91mm, LY30 0-4,3%, LY60 0-8,09%.
Resultatene viser at de estimerte referanseintervallene var noe smalere enn de
tidligere benyttet ved Dyresykehuset – smådyr, NMBU. Forskjellene kan ha sammenheng med liten utvalgsstørrelse, preanalytiske eller analytiske variasjoner, eller ulikheter mellom populasjonene som er benyttet i denne og i tidligere studier. Det bør gjennomføres nye utregninger med et større studieutvalg for å øke styrken til studien.Thromboelastography (TEG) is an analytical technique that gives information about a patient’s coagulation profile and is increasingly utilized in veterinary medicine. It is used in trauma evaluation, pre-, intra-, and postoperative monitoring, and in coagulation diagnostics.
A TEG-analysis will specifically examine coagulation factors, concentration and function of thrombocytes, concentration and function of fibrinogen, concentration of thrombin and the lysis of the blood clot. The analysis will give specific information as to where in the coagulation cascade the error occurs. This will be helpful in both diagnosing and deciding treatment options.
In our study we wished to create a reference interval for the different parameters, R-time, Ktime, α-angle, MA and LY30/LY60. The reference interval was based on TEG-analyses from a sample of 22 clinically healthy dogs. Statistical analysis was performed using both bootstrapping and the robust method. Our reference values were R-time: 1,52-7,28 min, Ktime: 0,64-2,91 min, α-angle: 53,51-76,53 degrees, MA: 45,84 – 67,97mm, LY30: 0-4,3% and LY60: 0-8,09%.
Our findings indicate that the reference intervals for these TEG parameters were generally slightly lower and narrower than those previously used at the Small Animal Hospital at NMBU. This variation may be attributed to the limited sample size, preanalytical or analytical variability, or differences in the study population compared to the population used to derive the previous reference values.VE
Investigating the Impact of Axon Activity on Measured Brain Potentials
Full text linkThis thesis investigates the impact of axonal activity on measured
brain potentials, emphasizing the biophysical mechanisms underlying
electroencephalography (EEG) and electrocorticography (ECoG) signals.
Through computational modeling and simulation using detailed neuron
models in the NEURON simulation environment and extracellular poten-
tial computations with LFPy, the study explores how action potentials
(APs) generated in axons contribute to extracellular potentials. Specif-
ically, the influence of axonal signals on the amplitude and waveform
of recorded extracellular potentials was systematically examined across
varying neuron populations and electrode configurations. Results indi-
cate that axonal activities can affect both the shape and amplitude of
measured signals, especially under conditions resembling experimental
EEG and ECoG recordings, for synchronized and large populations. The
study highlights important implications for interpreting electrophysiolog-
ical data, particularly regarding source localization and the biophysical
basis underlying brain imaging techniques. Additionally, limitations such
as the idealized modeling assumptions and recommendations for future
research are discussed
Assessment of Microsatellite Instability in Ovarian Cancer among Norwegian Women
Full text linkAbstract
Background: Ovarian cancer (OC) is a highly lethal gynaecological malignancy, often
diagnosed at an advanced stage. Microsatellite instability high (MSI-H) is a molecular
phenotype resulting from defective mismatch repair (dMMR). While MSI-H is an established
biomarker for colorectal and endometrial cancers, its prevalence and significance in OC
remain comparatively underexplored. In OC, MSI-H is less common but plays a critical role
as a biomarker for Lynch syndrome (LS) and as a predictive factor for the efficacy of
immune checkpoint inhibitors in immunotherapy. This study aimed to investigate the
prevalence of MSI-H in OC among Norwegian women.
Methods: The study investigated the frequency of MSI-H in 61 OC samples from Norwegian
patients using droplet digital PCR with a validated panel of mononucleotide markers (BAT25,
BAT26, NR21, NR24, and MONO27).
Results: MSI-H was identified in 4 out of 61 cases (6.6%), all of which were classified as the
clear cell carcinoma subtype. Notably, no MSI-H cases were found among endometrioid, lowgrade serous, or high-grade serous tumours.
Conclusion: We identified MSI-H in 6.6% of OC cases, underscoring the potential for
hereditary cancer diagnosis and enabling these patients to benefit from targeted
immunotherapy. This finding highlights the need for expanded studies to better understand the
frequency of MSI-H and its therapeutic implications. While immunotherapy represents a
promising treatment option for MSI-H/dMMR tumours, clinical evidence in OC remains
limited. Thus, this study emphasizes the importance of routine MSI-H testing to guide genetic
counselling and inform future treatment strategies, while also supporting the necessity for
further research into the role of immunotherapy in this molecular subgrou