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Estimering av berggrunns sedimenttykkelse med Kriging vs. Maskinlæringsmodeller
Denne avhandlingen hadde som mål å finne de beste regresjonsmetodene for å estimere berggrunnens sedimenttykkelse rundt Årungen, ved å sammenligne Kriging Interpolering med Maskinlæring-metoder. Nøyaktig modellering er viktig i flere samfunnsutfordringer, inkludert; å finne grunnvanns lokasjoner, produksjon av geotermisk varme og sikkerhet for infrastruktur i byplanlegging. Vi forsøkte å finne modellene som var best utstyrt for ulike mål, inkludert: Hvilken modell (1) gir de beste prediksjons målingene, (2) har de mest stabile resultatene med den laveste prediksjons variasjonen, (3) gir de mest realistiske prediksjons-overflatene, og (4) er den mest praktiske? GRANADA borehulls database, NADAG borehull, digitale løsmassekart og Kartverket digitale høydedata-modeller ble brukt for å lage nøyaktige data. Semivariogram tilpasning og parameter justering ble brukt på flere implementeringer av Kriging, for å optimalisere deres ytelse. Et representativt utvalg av Maskinlæring-regresjonsmodeller ble brukt og optimalisert ved hjelp av grid-søk-metoden. Det ble gjennomført flere runder med kryssvalidering for å sikre trygghet til resultatene. KNN-modellene forklarte 67% variansen, men med dårlige prediksjons overflater. Modellene Kriging og XGBoost var i stand til å forklare 64% av variansen med sine prediksjoner, samtidig som de hadde realistiske prediksjons-overflater. Kriging-interpolasjonsmetoden kom ut på topp i de fleste av bedømmelseskriteriene, med XGBoost på andreplass. Basert på våre data og metoder som er brukt, konkluderer vi med at Kriging fortsatt er det beste innen overflate regresjon.This thesis aimed to find the best regression methods to estimate the bedrock sediment thickness around Lake Aarungen, by comparing Kriging Interpolation to Machine Learning methods. Accurate modeling is important in several challenges within society, including; finding groundwater locations, production of geothermal heat, and the safety of infrastructure in urban planning. We attempted to find the models best equipped for unique goals, including: What model (1) gives the best prediction performance metrics, (2) has the most stable results with the lowest prediction variation, (3) produces the most realistic prediction surfaces, and (4) is the most practical? GRANADA borehole database, NADAG drill holes, Digital Query Maps, and Kartverket Digital Elevation models were used to create accurate data. Semivariogram fitting and parameter tuning was used on several implementations of Kriging, to optimize their performances. A representative selection of Machine Learning regression models was used and optimized using grid search. Several rounds of cross-validation were conducted to ensure confidence in the results. The KNN models explained 67% of variance, although with poor prediction surfaces. The models of Kriging and XGBoost were able to explain 64% of the variance with their predictions, while having realistic prediction surfaces. The kriging interpolation method came out on top in most of the judging criteria, with XGBoost second. Based on our data and methods used, we conclude that Kriging remains the state-of-the-art in surface regression
Resharing spaces, services and mobility: Developing a reshareability index for sustainable planning in Oslo
Recent studies on sharing cities and sharing economies have focused on what can be (or is being) shared, such as public spaces, food, mobility, ideas, knowledge, governance strategies, as well as community facilities, such as places for working, education and welfare. Following this emerging trend of sharing, this paper explores the novel approach of resharing, that aims to support, amongst other things, the integration of mobility sharing and different forms of space sharing in residential, office and commercial buildings. Firstly, the study presents a novel theoretical and conceptual approach to (re)sharing, and secondly, it reports on an empirical analysis conducted in the urban district of Hovinbyen in Oslo, using the sub-districts of Løren and Økern as the two main cases. The study analyzes existing preconditions for reshareability and suggests an index of reshareability to guide future developments. Løren is, to some extent, better equipped than Økern to apply the resharing approach, and can thus become a place for further experimentation with local communities and stakeholders. The study contributes to understanding and assessing the reshared qualities and characteristics of city neighborhoods, which can provide a foundation for developing planning strategies to make local neighborhoods more ‘sharing oriented’ or ‘reshareable’.Resharing spaces, services and mobility: Developing a reshareability index for sustainable planning in OslopublishedVersio
An examination of industrial park development in Lillesand municipality, along road connection E18 Kristiansand - Grimstad, and its effects on landscape and society
Abstract
This master's thesis investigates the impacts of the road connection, E18 KristiansandGrimstad, on the landscape and urban development, focusing on the emergence of in-between city development in Sørlandsparken and other nearby industrial areas in Lillesand municipality (see figure 1 and 2 below). The study explores how such infrastructural expansions contribute to landscape degradation, characterized by urban sprawl and the transformation of rural landscapes into commercialized zones.
Through a combination of literature review, document analysis and field observations, the research identifies significant changes in land use, aesthetics, and societal dynamics as a result of the road connection.
Some challenges include the loss of natural landscapes, fragmentation, increased car dependency, and reduced public spaces. On the other hand, the development has stimulated economic growth, regional connectivity, and accessibility, which presents opportunities for future urban planning.
The findings emphasize the conflict between economic development and landscape conservation, and highlighs the necessity for a balanced approach in regional planning to ensure sustainable development. This thesis contributes to the understanding of the inbetween city phenomena, and provides insights into the complex interplay between infrastructure projects and landscape transformation
Comparing approaches towards spontaneous vegetation in urban green structures
Urbanization causes negative environmental effects and leads to pressure on the nature within and surrounding cities. Increasing the levels of wildness in urban areas is a form of nature-based solution that can improve the biodiversity and improve residents’ well-being.
This study aims to find green structure approaches towards urban spontaneous vegetation in today’s Berlin, Germany and Oslo, Norway. This is done through document analysis of the cities’ planning documents.
The overall aim for the Berlin documents can be summarized as a wish to expand nature and wilderness in urban development areas, conserve biodiversity and ensure green access and high-quality environment for the residents. The overall aim of the Oslo documents is to design the urban landscape with local and sustainable measures, make a safe and attractive parks and open spaces.
This study finds that Berlin has a general positivity towards foreign species and monitor invasive species, while Oslo is negative towards foreign species because of the threat they put on Oslo’s indigenous species. Berlin looks at all green structures as part of biodiversity, even spontaneous vegetation, while Oslo wants preserve biodiversity by designing urban green spaces.
The background history and available land may be a factor that decides the acceptance towards urban spontaneous vegetation. Both Oslo and Berlin have a high construction development pressure, while only Berlin has sufficient land available for construction. Small patches of vegetation have a higher amount of invasive or foreign species, and indigenous species has a higher risk at surviving in bigger patches
Urban kultur - Sted, identitet og tilhørighet i en globalisert verden
Verden og samfunnet preges av hyppige endringer som øker i hastighet. Overgangen fra et industrielt samfunn til et informasjons- og kunnskapssamfunn har endret byenes rolle fra å være møteplasser og smeltedigler av kulturer, til strukturer der tradisjonell funksjonalitet kan synes å tilhøre fortiden. Samtidig har samfunnet blitt mer mangfoldig, med så mye som 80% av Norges befolkning bosatt i urbaniserte områder. Denne utviklingen fremhever nye utfordringer og muligheter.
Midt i disse endringene synes identitet å bli nedprioritert. Oppgaven adresserer hvordan byens mange identiteter og kulturer påvirkes av å ikke være en del av utformingen av stedene vi bor på. Den utforsker fenomenet "urban kultur" og hvordan de mange unike identitetene i byenes mangfoldige landskap får uttrykt seg og bidrar til å skape fellesskap som reflekterer dette mangfoldet.
Studien utforsker hvordan sosiale, kulturelle og romlige uttrykk i ulike bymiljøer manifesterer seg som kollektiv stedsidentitet over tid, og hvordan lokal identitet kan bevares og fremmes i en stadig mer globalisert verden. Det undersøkes hvordan byområder formes og påvirkes av lokalsamfunnets sosiale og kulturelle adferd, samt hvordan disse adferdsmønstrene kan bli begrenset av byområdenes struktur, demografi og kontroll.
Ved hjelp av et tverrfaglig kunnskapsgrunnlag, flere stedsanalyser og en tredelt dokumentanalyse, analyseres mulighetene og utfordringene som dagens planlegging, samfunnsmessige forhold, politikk, markedskrefter og miljøpsykologi stiller, med mål om å avdekke hvordan befolkningen kan manifestere særpreg i sine nabolag gjennom strategier og planleggingsføringer.
Til slutt søker oppgaven å forstå den komplekse dynamikken som former våre urbane miljøer, og hvordan urban kultur kan påvirke og forsterke urbane utviklingsprosesser. Dette gjøres for å fremme mer levende, inkluderende og identitetsrike nabolag. Ved å vurdere hvordan innbyggere kan få en sterkere stemme i byutviklingen, utforskes mange ulike perspektiver som belyser et tidligere lite beskrevet fenomen i et forsøk på å demokratisere medvirkning i byplanlegging. Studien peker mot en trend der sosiale hensyn vektlegges mindre i motstridende hensyn, og at mange steder planlegges for å være attraktive i en internasjonal sammenheng. Oppgaven utforsker derfor hvordan vi kan planlegge med kulturen på en måte som respekterer og fremmer lokale identiteter.The world and society are marked by rapid changes, which appear to be accelerating. As society transitions from an industrial to an information and knowledge-based society, the traditional role of cities as meeting places and cultural melting pots seems to belong to the past. However, society has become more diverse than before, with as much as 80% of Norway's population now living in urban areas. Amidst these changes, one particular aspect seems to have been significantly overlooked or downplayed: identity. What happens when the many identities and cultures of a city do not participate in shaping the spaces we inhabit?
This thesis seeks to understand the phenomenon of "urban culture." How do the various unique
identities within the diverse landscapes of cities express themselves and contribute to creating a community that reflects this diversity? By exploring how the social, cultural, and spatial expressions in different urban environments manifest as collective place identity over time, this study aims to highlight how local identity can find its place in a global world. The thesis investigates how urban areas can be shaped and controlled by the social and cultural behaviors of local communities, and how these behaviors can be limited by the structure, demographics, and governance of urban areas.
Utilizing an interdisciplinary knowledge base, multiple place analyses, and a three-part document analysis, this thesis examines the opportunities and challenges posed by current planning, societal conditions, politics, market forces, and environmental psychology concerning the population's ability to manifest uniqueness. Employing photography combined with theory to uncover opportunities and challenges, and by evaluating these findings against development strategies and guidelines, the thesis seeks to illuminate the scope for communities to influence their neighborhoods.
In an effort to understand the infinite complexity that shapes and determines our urban environments, the thesis explores how urban culture can shape and enhance urban development processes to promote more vibrant, inclusive, and identity-rich neighborhoods in an increasingly globalized world. By assessing the opportunities for residents to have a stronger voice in urban development, the thesis explores various perspectives that illuminate a previously under-described phenomenon, in an attempt to democratize participation in urban planning in a world that never stands still.
The trend indicates that social considerations are being weighed less in conflicting interests, and that many places are planned to be attractive in an international competition. Recent place development seems to plan for culture, where this thesis explores how we can plan with culture
Småbåthavnenes fremtid i Indre Oslofjord
Denne masteroppgaven undersøker hvordan allmennhetens tilgang og marint naturmangfold i større
grad kan ivaretas i småbåthavner i Indre Oslofjord i fremtiden. Oppgaven tar utgangspunkt i seks utvalgte
småbåthavner, i kommunene Oslo og Bærum. Gjennom analyser og registreringer av bruk av stedet og
naturmangfold ved de seks småbåthavnene, identifiseres fire hovedutfordringer knyttet til allmennhetens
tilgang og marint naturmangfold: Arealkonflikt mellom småbåthavn og naturverdier, marin forurensing
som konsekvens av bruk, drift og vedlikehold av småbåter, store fjordnære arealer avsatt til båtopplag, og
privatisering av brygger, småbåthavner og båtliv.
I småbåthavnen Solvikbukta og Lakseberget er alle de fire utfordringene representert, og det skisseres
her en stedsutvikling som skal fremme allmennhetens tilgang og marint naturmangfold, uten at båtlivet
forkastes. Utviklingsplanene for Solvikbukta og Lakseberget strekker seg over flere år fra 2030 til 2050, og
baserer seg i stor grad på en omdisponering av arealer både på land og i vann, samt en transformasjon
av folks forventninger til å eie egen, individuell båt. Videre peker oppgaven på overføringsverdi mellom
løsningene for Solvikbukta og Lakseberget og de fem resterende småbåthavnene oppgaven tar for seg.
Oppgaven illustrerer hvilke grep som må tas i praksis for å nå nasjonale og internasjonale mål knyttet til
bevaring av naturmangfold, og for å styrke allmennhetens tilgang til fjorden og imøtekomme den økende
befolkningens behov for kystnære rekreasjonsarealer i fremtiden.This master's thesis examines how public accessibility and marine natural diversity in the future can be
prioritized to a greater extent in the harbors of the Inner Oslofjord. The thesis covers six large marinas in the
municipalities of Oslo and Bærum. Through registrations of use of the site and natural diversity at the six
marinas, four main challenges at the marinas related to public accessibility and marine natural diversity
are identified: Territorial conflict between harbors and natural values, marine pollution as a consequence
of the use, operation and maintenance of boats, large areas by the fjord set aside for boat storage, and
privatization of wharves, harbors and boating.
In the marina “Solvikbukta and Lakseberget”, all four challenges are represented, and the thesis therefore
proposes a future site development to enhance public accessibility and marine natural diversity. The
development plans for Solvikbukta and Lakseberget are set for the years 2030, 2040 and 2050, and are
largely based on a reallocation of the boats use of space, both on the landside and on the fjord, and a
transformation of people's expectations of owning their own individual boat. Furthermore, the thesis points
to transferability between the solutions for Solvikbukta and Lakseberget and the four remaining marinas
the thesis covers.
The assignment illustrates what steps must be taken in practice to achieve national and international
goals related to the conservation of natural diversity, and to accommodate the growing population's
need for coastal recreation areas in the future
Norwegian Non-EU ETS-firms’ participation in Voluntary Carbon Markets and Alignment with national emissions reduction targets
Corporate actors within non-EU ETS sectors will likely play a significant role in reaching Norway’s target of reducing greenhouse gas emissions by at least 55% by 2030 compared to emissions levels in 1990, as a crucial part of reaching the national targets hinges on significant emissions reduction within these sectors. However, the systems surrounding these firms’ practices and determinants on emissions reduction and removal measures such as the purchase of voluntary carbon credits [VCCs] from voluntary carbon markets [VCMs] appears misaligned with both the emissions reduction targets set on the national level and the non-EU ETS sector-level.
This thesis aims to understand the extent and determinants of Norwegian non-EU ETS sector actors’ participation in VCM through the form of VCC purchases and attempts to assess and address the need for system adaptations ensuring alignment of these practices with reaching national emissions reduction targets by 2030. Using a mixed-methods approach through an online questionnaire and semi-structured interviews with respectively 74 and six (6) respondents from firms in non-EU ETS sectors, the following three research questions were addressed: 1. How and to what extent do firms within Norwegian non-EU ETS sectors participate in the purchase of voluntary carbon credits?; 2. Which determinants influence the voluntary carbon credit practices of firms within Norwegian non-EU ETS sectors?; and
3. Which system adaptations might facilitate alignment between practices of Norwegian firms in non-EU ETS sectors purchasing or hypothetically purchasing VCCs, and Norway’s target of reducing national emissions by at least 55% of 1990-levels by 2030?
Very low levels of VCM participation were identified among the studied firms, with only two firms reporting to currently purchase VCCs. Meanwhile, a number of firms reported hypothetically considering purchasing VCCs in the future. The purchasing and hypothetically purchasing firms’ type of VCM participation was mostly characteristic of inclination towards VCCs from carbon capture and storage [CCS] projects for the sake of climate financing or compensating for remaining emissions, with some reference to forest and land projects for carbon removal, and climate reduction projects in developing countries. The firms exhibit a clear tendency of prioritising reducing their own emissions before hypothetically purchasing VCCs, and display a clear preference for credible, measurable, and sector-relevant measures. In analysing determinants of current and hypothetical VCM participation through a thematic analysis, four main themes of determining factors were identified, namely 1. timing and priority of actions, 2. firms’ conditions for financial stability and profitability, 3. firms’ incentives and motivations in assessment of VCM participation, and 4. firms’ knowledge and preferences regarding corporate social responsibility [CSR], VCMs and VCCs. The firms current and hypothetical VCM participation display a clear tendency to be dominated by strategic considerations of upholding stakeholder accountability and legitimacy for financial survival, with discussable elements of altruism in choices not to engage in VCMs since they do not want to buy their way out of the responsibility of reducing their own emissions. Furthermore, they exhibit clear tendencies of dependence on customer demand and industry peers in adapting to altered conditions for competition and a lack of consensus on how to meet emissions reduction demands.
Proposed system adaptations for increased alignment between non-EU ETS sector firms’ currently purchasing or considering purchasing VCCs and Norway’s emissions reduction targets include strengthening the role of civil society in forming sector-relevant policy and regulation in line with national circumstances, accelerated investment in emissions-reducing infrastructure, and capacity-building and collaboration across bodies of government, industry, academia and civil society.Corporate actors within non-EU ETS sectors will likely play a significant role in reaching Norway’s target of reducing greenhouse gas emissions by at least 55% by 2030 compared to emissions levels in 1990, as a crucial part of reaching the national targets hinges on significant emissions reduction within these sectors. However, the systems surrounding these firms’ practices and determinants on emissions reduction and removal measures such as the purchase of voluntary carbon credits [VCCs] from voluntary carbon markets [VCMs] appears misaligned with both the emissions reduction targets set on the national level and the non-EU ETS sector-level.
This thesis aims to understand the extent and determinants of Norwegian non-EU ETS sector actors’ participation in VCM through the form of VCC purchases and attempts to assess and address the need for system adaptations ensuring alignment of these practices with reaching national emissions reduction targets by 2030. Using a mixed-methods approach through an online questionnaire and semi-structured interviews with respectively 74 and six (6) respondents from firms in non-EU ETS sectors, the following three research questions were addressed: 1. How and to what extent do firms within Norwegian non-EU ETS sectors participate in the purchase of voluntary carbon credits?; 2. Which determinants influence the voluntary carbon credit practices of firms within Norwegian non-EU ETS sectors?; and
3. Which system adaptations might facilitate alignment between practices of Norwegian firms in non-EU ETS sectors purchasing or hypothetically purchasing VCCs, and Norway’s target of reducing national emissions by at least 55% of 1990-levels by 2030?
Very low levels of VCM participation were identified among the studied firms, with only two firms reporting to currently purchase VCCs. Meanwhile, a number of firms reported hypothetically considering purchasing VCCs in the future. The purchasing and hypothetically purchasing firms’ type of VCM participation was mostly characteristic of inclination towards VCCs from carbon capture and storage [CCS] projects for the sake of climate financing or compensating for remaining emissions, with some reference to forest and land projects for carbon removal, and climate reduction projects in developing countries. The firms exhibit a clear tendency of prioritising reducing their own emissions before hypothetically purchasing VCCs, and display a clear preference for credible, measurable, and sector-relevant measures. In analysing determinants of current and hypothetical VCM participation through a thematic analysis, four main themes of determining factors were identified, namely 1. timing and priority of actions, 2. firms’ conditions for financial stability and profitability, 3. firms’ incentives and motivations in assessment of VCM participation, and 4. firms’ knowledge and preferences regarding corporate social responsibility [CSR], VCMs and VCCs. The firms current and hypothetical VCM participation display a clear tendency to be dominated by strategic considerations of upholding stakeholder accountability and legitimacy for financial survival, with discussable elements of altruism in choices not to engage in VCMs since they do not want to buy their way out of the responsibility of reducing their own emissions. Furthermore, they exhibit clear tendencies of dependence on customer demand and industry peers in adapting to altered conditions for competition and a lack of consensus on how to meet emissions reduction demands.
Proposed system adaptations for increased alignment between non-EU ETS sector firms’ currently purchasing or considering purchasing VCCs and Norway’s emissions reduction targets include strengthening the role of civil society in forming sector-relevant policy and regulation in line with national circumstances, accelerated investment in emissions-reducing infrastructure, and capacity-building and collaboration across bodies of government, industry, academia and civil society
A Data-Driven Exploration: Providing Early Feedback on Socioeconomic Mitigation Strategies for Climate Change
The current rate of climate change is unprecedented in millennia and represents one of humanity’s most significant
issues for the 21st century, with serious consequences for both civilization and the environment if no action is taken.
To reduce the future impact of changes, coordinated international efforts such as those outlined in the Paris Agree-
ment are required. However, mitigation and adaptation efforts should not only be extensive, but also be precise in
order to align international socioeconomic development with temperature targets as well as other societal and envi-
ronmental sustainability goals. In order to inform about the future climate, extensive efforts through institutions such
as the Intergovernmental Panel on Climate Change (IPCC) have resulted in extensive scenario-based research with
Earth system models (ESMs). This work forms the knowledge basis for information provided to the worlds decision
makers.
Currently, established methods for near-term feedback on mitigation efforts are mainly based on the global surface
air temperature (GSAT) variable alone. By these methods, a clear separation of socioeconomic pathways does not
emerge before 20 to 30 years after emission separation due to the internal variability of the climate system. Here, we
use a machine learning approach to create a separation of the climatic response from the socioeconomic development
pathways based on ESM output data. This policy feedback strategy has not been described previously. Using 40
realizations of ACCESS-ESM1.5 under SSP1-2.6 and SSP5-8.5, where emission starts to differ in 2015, we estimate
that a classification accuracy above 80 % is attainable by the appropriate feature-set/model combinations as early as
2026 based on the mean accuracy across 50 random states. However, the uncertainty of estimated accuracy is greatly
reduced towards 2030–2040, indicating that real-world applications are not yet attainable. Our findings suggest that
classification models trained on ESM-forecasts have the potential to become a powerful tool for providing early feedback
on how the climate system responds to mitigation efforts
Corruption and Democracy: Comparative Dynamics of Uruguay and Venezuela
This thesis examines the dynamics of corruption and its impact on democracy in Uruguay and Venezuela. It focuses specifically on how these nations differ in their approaches to handling corruption. By analyzing their recent political history within the context of corruption and democratic stability, the study employs multidimensional, analytical, and comparative methods to find and explore these differences. In that process, this thesis establishes a theoretical framework that defines corruption and democracy, acknowledging their complex nature. Assuming that corruption has a destructive effect on democracy, the research delves into various scholarly sources and investigates how different types of corruption undermine political institutions and processes, and thus weakening the stability of democratic governance. With a mixed- method approach and a combination of secondary source analysis and contextual case studies of Uruguay and Venezuela, the study then presents the patterns of corruption's impact in each country, particularly the mechanisms through which corruption perpetuates and worsens democratic weak points, contributing to political deterioration and distrust of the society towards the government. Ultimately, the thesis seeks to present nuanced patterns of corruption's impact in each country, offering insights into the pathways through which corruption undermines democratic structures and fosters political decay
Identifisering av bioaktive komponenter i mat ved hjelp av ex vivo fordøyelse, peptidomisk profileringsmetode og in silico-modellering
Food bioactives are defined as substances in food that interact with human biological processes, affecting body functions or conditions and ultimately health. Bioactive peptides (BAPs) deriving from dietary proteins can, depending on their bioavailability, circulate in the blood stream to reach target organs, exerting systemic effects, that influence disease development, in terms of both beneficial and adverse
outcomes. This thesis focused on exploring bioactive peptides from milk, wheat, faba beans and peas through ex vivo digestion, peptidomic profiling and in silico modelling. The core areas, bioavailability, bioaccessibility and bioactive potential were explored.
Milk β-casomorphin-7 (BCM7) is a heptapeptide deriving from bovine β-casein. Earlier research claim that the release of BCM7 during gastrointestinal (GI) digestion is restricted to the A1 genetic variant of β-casein. This peptide has an opioid-like structure and has been implicated in influencing digestive processes and potentially impacting neurological functions, among others. In Paper 1, the effect of β-casein genetic variants on the release of BCM7 during ex vivo GI digestion with human enzymes was investigated. It was found that genetic variation affected hydrolysis of β-casein and the release of BCM7, but the release was not solely linked to the A1 variant as previously suggested. In Paper 2, the
investigation expanded to include several β-casein variants (A1, A2, F, and I) and quantified BCM7 release after ex vivo GI digestion of milk. This confirmed the results obtained on digestion of purified β-
casein, Paper 1, although larger differences in BCM7 release between variant A1 and A2 were observed. However, all milks released BCM7 after ex vivo GI digestion. Focusing on exploring bioaccessibility of BCM7, the work in Paper 3 monitored the peptide through ex vivo GI digestion and porcine jejunal brush border membrane digestion. It was found that more than 40% of BCM7 was degraded after 2h brush
border membrane digestion, and only 5% remained intact after 24h. This questions the bioactivity and potential health impacts of BCM7 and its fragments.
Wheat-related disorders is increasing globally, and the extensive breeding of modern wheat varieties has been implicated. Ancestral wheat species such as einkorn, emmer and spelt, has undergone minimal changes during domestication of wheat, and are believed to contain lower levels of components triggering wheat disorders. Therefore, in Paper 4, different wheat types (common and ancestral) were compared regarding release of T cell epitope-containing immunogenic peptides following ex vivo digestion. The immunodominant peptides of gliadins (33mer, 25mer and 26mer) were not found in their intact form in any of the wheat digesta, but as degraded fragments. Additionally, the ancestral wheat types released fewer immunogenic peptides than common wheat varieties. In Paper 6, the peptidomic profile was investigated for the identification of potential opioids. The ex vivo digestion resulted in release of fewer opioid-containing peptide sequences in einkorn (n=6) and spelt (n=5), compared to the modern wheat varieties Bastian (n=24) and Mirakel (n=26), suggesting differences in opioid potential between ancestral and common wheat types. Although the ancestral wheat types still pose a risk and thus cannot be considered safe for celiac patients, their lower content of immunogenic and opioidcontaining peptides indicates that they may trigger weaker sensitivity reactions and could possibly reduce onset of celiac disease in genetically predisposed individuals.
Legumes remain underutilized in the western diet despite their status as nutritional and sustainable protein sources. They also hold potential as sources of BAPs, but research is still limited, particularly regarding their bioavailability, bioaccessibility and bioactivity during physiological relevant human digestion. The work presented in Paper 5, aimed at exploring the bioactive potential of faba beans and peas, where
protein-enriched fractions of these legumes were subjected to ex vivo GI digestion. Over 400 unique peptides were identified following ex vivo digestion. Through in silico approach, peptide candidates were selected and tested for their immunemodulating properties in an in vitro cell model. Both pea- and faba bean-derived peptides showed to significantly decrease inflammatory response in Caco-2 cells, suggesting immune-modulating properties. Also, the in silico approach identified several hundred BAPs encrypted within the digesta of pea and faba bean, as well as peptide sequences with homology (>90%) to several known allergenic epitopes in the Fabaceae family. This work highlights the potential of legumes as a health-promoting food source and the advantages of combining in vitro, ex vivo and in silico approaches
to explore bioactive potential of legumes, for which extensive evidence is still lacking.
While most research has highlighted BAPs beneficial effects, this thesis has emphasized investigation of BAPs with potential adverse effects. Still, controlled clinical trials are needed to ascertain any health impacts of these BAPs. Nevertheless, the combined methodological approach herein shows great potential and should be exploited in future food bioactive research and could be extended to pharmacological research.Bioaktive komponenter i mat defineres som aktive stoffer som påvirker ulike biologiske prosesser i kroppen etter matinntak og kan således ha effekt på helsen. Bioaktive peptider (BAP) frigjøres fra proteiner etter fordøyelse, og vil dersom de er biotilgjengelige, overføres fra tarmen til blodbanen og påvirke ulike organer som kan ha både positiv og negativ innvirkning på sykdomsforløp. Denne avhandlingen utforsket bioaktive peptider fra melk, ulike hvete sorter, faba-bønner og erter, ved å benytte en ex vivo gastrointestinal (GI) fordøyelsesmodell med humane enzymer. Itillegg ble peptidomisk profileringsmetode og in silico modellering anvendt for å undersøke peptidenes biotilgjengelighet og bioaktive potensiale.
β-casomorfin-7 (BCM7) er et heptapeptid som kan dannes når proteinet β-kasein (β- CN) i melk brytes ned under fordøyelse. Tidligere forskning har vist at BCM7 kun frigjøres under fordøyelse av genetisk variant A1 av β-CN. Dette peptidet har en opioidlignende struktur og kan blant annet påvirke fordøyelsesprosesser og nevrologiske funksjoner. I Artikkel 1 ble effekt av genetisk variant av β-CN vurdert mot frigjøring av BCM7 under ex vivo GI fordøyelse. Genetisk variant påvirket grad av nedbryting av β-CN og hvor raskt BCM7 ble dannet, men frigjøring av BCM7 var ikke begrenset til kun A1-varianten som tidligere påstått, da BCM7 også ble identifisert fra A2 varianten. I forsøket omtalt i Artikkel 2 ble flere varianter av β-CN (A1, A2, F og I) inkludert, og mengde BCM7 som ble dannet etter ex vivo GI fordøyelse av melk analysert. Dette forsøket bekreftet resultatene fra fordøyelse av renset β-kasein i Artikkel 1, men her ble det funnet større forskjeller i mengde BCM7 frigjort fra variant A1 sammenlignet med variant A2. BCM7 ble dannet etter ex vivo GI fordøyelse av alle de fire variantene av β-CN. I Artikkel 3 ble stabilitet og eventuell videre nedbryting av BCM7 undersøkt under ex vivo GI fordøyelse etterfulgt av enzymer isolert fra børstesømmembraner i tolvfingertarm hos gris. Mer enn 40 % av BCM7 ble brutt ned etter 2 timer børstesøm-fordøyelse, og kun 5 % var intakt etter 24 timer. Dette stiller spørsmål ved bioaktivitet og mulige helseeffekter av BCM7, siden det spaltes videre til mindre fragmenter.
Det er en global økning i ulike tarmlidelser relatert til inntak av hvete, noe som kan være knyttet til moderne hveteforedling. Urhvete er ikke foredlet i samme grad og antas å inneholde lavere nivåer av komponenter som utløser hvete-sensitivitet. I Artikkel 4 ble immunogene peptider som kan binde til T-celler identifisert etter ex vivo fordøyelse av urhvete og moderne hvetetyper. De mest kjente immundominante peptidene fra gliadiner (33mer, 25mer og 26mer) ble ikke funnet intakte, men som
nedbrutte fragmenter. I tillegg frigjorde urhvete færre immunogene peptider enn moderne hvetesorter. I Artikkel 6 ble potensielle opioider undersøkt etter ex vivo fordøyelse av de samme hvetesortene. Det ble identifisert færre opioide peptidsekvenser i einkorn (n=6) og spelt (n=5), sammenlignet med de moderne
sortene Bastian (n=24) og Mirakel (n=26). Dette tyder på at foredling kan ha tilført opioid potensiale til hvete. Selv om de gamle hvetetypene fortsatt utgjør en risiko og dermed ikke kan anses som trygge for cøliakere, indikerer lavere innhold av immunogene og opioide peptider at de kan utløse svakere sensitivitetsreaksjoner og muligens redusere utvikling av cøliaki hos genetisk disponerte individer.
Til tross for at belgfrukter er næringsrike og bærekraftige kilder til protein, er de fortsatt lite benyttet i vårt kosthold. De kan også være kilder til bioaktive peptider, men forskningen er begrenset, spesielt med hensyn til å kunne påvise biotilgjengelighet og bioaktivitet i kroppen. Arbeidet presentert i Artikkel 5, hadde
som mål å undersøke biotilgjengelighet og det bioaktive potensialet til faba-bønner og erter ved hjelp av ex vivo og in silico modeller. Etter ex vivo GI fordøyelse av proteinrike fraksjoner ble over 400 unike peptider identifisert. In silico-modellering ble benyttet til å velge peptider med bioaktivt potensiale, og immunmodulerende egenskaper til utvalgte peptider ble testet i en in vitro cellemodell. Både peptider fra
erter og faba-bønner viste signifikant reduksjon i inflammatorisk respons i Caco-2-celler, noe som tyder på immunmodulerende egenskaper. I tillegg avdekket in silico-modellering flere hundre bioaktive peptider som sekvenser i større peptider av både erter og faba-bønner etter fordøyelse. Det ble også funnet peptidsekvenser med høy grad av likhet (>90 %) med flere kjente allergen epitoper fra proteiner i fabaceae-familien. Dette arbeidet viser potensialet til belgfrukter som en helsefremmende matkilde, i tillegg til fordelene med å kombinere in vitro, ex vivo og in silico undersøkelser for å utforske deres bioaktive potensiale, som det fortsatt mangler omfattende bevis for.
Selv om flest studier har fremhevet positive helseeffekter av bioaktive peptider, har denne avhandlingen lagt vekt på å undersøke bioaktive peptider med mulige negative effekter. Kontrollerte kliniske studier er fortsatt nødvendige for å fastslå eventuelle helseeffekter av disse peptidene. Likevel viser den kombinerte metodiske tilnærmingen her stort potensiale og anbefales for fremtidig forskning på bioaktive komponenter i mat, og kan ytterligere utvides til andre fagområder slik som farmakologisk forskning