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    Energy and entropy stable numerical methods with injected boundary conditions

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    I denne avhandlingen studerer vi de kompressible Navier-Stokes-likningene formulert med både adiabatiske veggrandvilkår og fjernfeltvilkår. Selv om det er ukjent om disse likningene er velformulerte er de av stor interesse, og de er mye brukt innen numerisk fluiddynamikk. Et resultat av Strang (1964) sier at for ikke-lineære problem diskretisert ved hjelp av en differansemetode som er lineærstabil, er denne metoden konvergent for glatte løsninger. Altså finnes det teori vi kan bruke i analysen av Navier-Stokes-likningene. Derfor studerer vi her teori for velformulerte lineære problem, og stabilitet for numeriske metoder. Dette gjøres både for de kompressible Navier-Stokes-likningene, men også for lineære partielle differensiallikninger som modellproblem. Videre utleder vi entropiestimat for de ikke-lineære Navier-Stokes-likningene, et estimat som virker som et kriterium for den svake løsningen vi leter etter; den skal i tillegg til likningene tilfredsstille termodynamikkens andre lov. Hovedfokuset ved dette arbeidet er stabil håndtering av de adiabatiske veggrandvilkårene og fjernfeltvilkår for Navier-Stokes-likningene. Vi beviser at heftelsesvilkåret (eng.: no- slip condition) kan bli implementert eksakt og fremdeles resultere i et entropiestimat når teknikken brukes i kombinasjon med delvissummasjonsoperatorer (SBP-operatorer) som har diagonale normmatriser og randmatriser. Vi introduserer også en ny metodikk for å sette fjernfeltvilkår, og beviser at den fører til et entropistabilt skjema for de kompressible Navier-Stokes-likningene. Teknikken er i tillegg lineært velformulert. Gjennom hele arbeidet bruker vi SBP-operatorer på grunn av deres gode stabilitetsegenskaper. Vi beviser også at en litt endret versjon av SBP-operatoren som tilnærmer den andrederiverte ved hjelp av endelig-volummetoden gitt av Chandrashekar (2016) er (svakt) konsistent, noe som gjør den egnet til å diskretisere de viskøse leddene i Navier-Stokes-likningene på ustrukturerte gitter.The compressible Navier-Stokes equation subject to both adiabatic wall boundary conditions and far-field boundary conditions are studied in this thesis. Although the well- posedness of these equations is generally unknown, they are of wide interest and are extensively used in computational fluid dynamics. A result by Strang (1964) states that if a non-linear problem is discretised using a difference method that is linearly stable, then this method is convergent for smooth solutions. That is, there exists theory we can use in the analysis of the Navier-Stokes equations. Thus, we study linear well-posedness and stability of numerical schemes both in the context of the compressible Navier-Stokes equations, but also linear partial differential equations as model problems. Furthermore, entropy estimates are derived for the fully non-linear Navier-Stokes equations, which pose as an admissibility criterion for the relevant weak solution we seek; it should additionally satisfy the second law of thermodynamics. The main focus of this work is the stable imposition of the adiabatic wall and far-field boundary conditions for the Navier-Stokes equations. In particular, we prove that the no-slip condition can be imposed strongly and still yield an entropy estimate when used in combination with diagonal-norm summation-by-parts (SBP) operators with diagonal boundary operators. Furthermore, we introduce a new methodology for setting far- field boundary conditions, and prove that it leads to an entropy stable scheme for the compressible Navier-Stokes equations. The procedure is additionally linearly well-posed. Throughout, we employ SBP operators due to their remarkable stability properties. We also prove that a slightly modified version of the finite-volume SBP approximation of the second-derivative given by Chandrashekar (2016) is (weakly) consistent, thus making it suitable for discretising the viscous terms of the Navier-Stokes equations on unstructured grids.Doktorgradsavhandlin

    Atlantic water inflow into the Arctic Ocean: studies of pathways, transport and mixing processes using observations from ships and autonomous underwater vehicles

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    Nordishavet spiller en viktig rolle i det globale klimasystemet. Produksjon av kaldt vann med høy tetthet, samt frysing av sjøis i Arktis, bidrar til å drive den Atlantiske meridionale omveltningssirkulasjonen og kan påvirke atmosfærens sirkulasjonsmønstre så langt sør som til midlere breddegrader. Atlanterhavsvann som strømmer gjennom Framstredet og Barentshavet, inn i Arktis, regulerer både produksjonen av vann med høy tetthet og utstrekningen av sjøis. Dermed har Atlanterhavsvann en nøkkelrolle i Arktis og det globale klimasystemet som helhet. Denne studien beskriver innstrømningsveiene til Atlanterhavsvann, samt de underliggende mekanismene som styrer innstrømningen, prosessene for varmetap og blanding med de Arktiske vannmassene nord for Svalbard og i det nordvestlige Barentshavet. Data samlet inn ved hjelp av autonome undervannsfartøy (AUV-er) er sentrale i denne studien. Mer enn 15 000 hydrografiske profiler er samlet inn i løpet av fem tokt og elleve AUV-oppdrag mellom 2018 og 2022, og er presentert i form av fire artikler. Data er samlet inn som en del av prosjektet Arven etter Nansen. Ved bruk av observasjoner langs kontinentalskråningen nord for Svalbard, mellom 12°Ø og 24°Ø, beskriver vi hydrografisk struktur, volumtransport og sirkulasjonsmønstre til Atlanterhavsgrensestrømmen. Volumtransporten til grensestrømmen når et maksimum på 3.0 ± 0.2 Sv i oktober, men styrken til grensestrømmen er følsom for vindstress, og dobler volumtransporten sin på mindre enn en uke når gjennomsnittlig vindstress over regionen endrer seg. En tidligere ukjent bunnintensivert vannstrøm observeres å strømme parallelt med grensestrømmen mellom 1500 og 2000 meter dybdekonturene. Historiske data i regionen støtter tilstedeværelsen av den bunnintensiverte vannstrømmen. Oppfølgingsstudiene konsentrerte seg om det nordvestlige Barentshavet. Målrettede målinger ved bruk av AUV-er gir en stor forbedring i romlig og tidsmessig dekning av observasjoner. For å utnytte teknologien, spesielt ved målinger av turbulens, utforsket vi potensialet til en propelldrevet AUV. Vi utstyrte AUV-en med en turbulenspakke og rapporterer datakvaliteten, samt diskuterer begrensningene av dissipasjonsestimater fra skjærsensorene. Det propelldrevet AUV-oppdraget i Barentshavet, vinteren 2021, varte i 5 timer, og AUV-en hadde en typisk horisontal hastighet på 1.1 m/s. AUV-en ble programmert for å finne og krysse maksimal temperaturgradient på 10, 20 og 30 m dyp langs 4 km strekk. Selv om AUV-vibrasjonene, på grunn av propellen, forstyrrer målingene med skjærsensorene, filtreres støyen bort ved å fjerne vibrasjonsinduserte komponenter fra skjær-spekter ved bruk av akselerometersignal. Dissipasjonsestimatene fra AUV-en viser god overensstemmelse med nærliggende vertikale mikrostrukturprofiler fra skip, noe som indikerer at turbulensmålingene fra oppsettet er pålitelige for dette relativt turbulente miljøet. Sirkulasjonsveier, hydrografi og volumtransport av Atlanterhavsvann og Arktiske vann i det nordvestlige Barentshavet utforskes ved hjelp av data fra tre tokt og ni glideroppdrag gjennomført mellom 2019 og 2022, samt historiske data samlet mellom 1950 og 2009. Vi setter søkelys på utveksling og dynamikk på tvers av Polarfronten og nærliggende område. Observasjonene våre viser at 0.9 ± 0.1 Sv av Atlanterhavvann når Polarfront-regionen før vannet sprer seg langs flere forgreninger og til slutt dykker under Arktiske vannmasser. Mengden Atlanterhavsvann som lagres nord for Polarfronten kontrolleres av tetthetsforskjellen mellom Atlanterhavsvannet og det Arktiske vannet, og nådde et maksimum på 90-tallet da det Arktiske vannet nord for fronten var spesielt ferskt. I nyere tid (2019 til 2022) ble Atlanterhavsvannet som strømmer inn i Barentshavet opptil 0.1 g/kg ferskere sammenlignet med tidligere tiår. Dette førte til en økt temperaturgradient på tvers av Polarfronten og en redusert transport av varmt vann nordover på tvers av fronten. Ved bruk av data fra to tokt og fire glider-oppdrag, spesifikt samlet for å undersøke dynamikken og variabiliteten til Polarfronten, beskriver vi strukturen til fronten, dens variasjon og forekomsten av blanding av vannmasser. Vi observerer at varmt og salt Atlanterhavsvann trenger inn under kaldere og ferskere Arktisk vann, noe som setter opp en baroklin front og en geostrofisk strøm med hastigheter opp mot 25 cm/s. Den estimerte østlige transporten fra den geostrofiske strømmen er 0.3 ± 0.2 Sv. Korttidsvariasjoner i dypet, under øvre grenselag, skyldes tidevannsstrømmer og mesoskala virvler. Effektene av tidevannsstrømmer er hovedsakelig begrenset til bunnsjiktet, mens virvlene betydelig påvirker posisjonen til fronten og endrer helningen til tetthetslinjene og følgelig den tilgjengelige potensielle energien i fronten. Betydelig transformasjon av vannmasser observeres på tvers av fronten, noe som sannsynligvis skyldes virvelindusert blanding langs tetthetskonturene. Til tross for sesongendringer i de øvre grenselag på tvers av fronten (0-100 m), forble posisjonen til fronten under 100 m dybde relativt uforstyrret. Samlet sett har artiklene i denne avhandlingen bidratt til å øke vår kunnskap om innstrømmingen av Atlanterhavsvann i Nordishavet, dens veier og mekanismer som kontrollerer blandingen og distribusjonen av varme fra Atlanterhavsvannet til de omkringliggende Arktiske vannmassene. Dette arbeidet representerer et viktig skritt i retning av å forstå Atlanterhavsvannet sin innflytelse på Nordishavet, noe som er avgjørende for bærekraftig forvaltning og for å forutsi fremtiden til de Arktiske økosystemene.The Arctic Ocean plays an important role in the global climate system. Dense water production and sea ice freezing in the Arctic contribute to the functioning of the Atlantic Meridional Overturning Circulation and can affect atmospheric circulation patterns as far south as mid-latitudes. The Atlantic Water (AW) inflow through Fram Strait and Barents Sea into the Arctic Ocean regulates both the dense water production and the sea-ice extent, thus has a key role in the Arctic Ocean and the global climate system. The transport of AW into the Arctic is the major heat and salt source to the Arctic Ocean and influences the onset of freezing and the functioning of marine ecosystems. This research contributes to the understanding of the inflow of AW into the Arctic Ocean through Fram Strait and the Barents Sea. The study describes the pathways of the AW inflow, as well as the underlying mechanisms controlling the inflow, processes of heat loss, and mixing with the surrounding waters north of Svalbard and in the northwestern Barents Sea. Essential to this study is data collected by means of autonomous underwater vehicles (AUVs) in challenging Arctic conditions. Data collected from five scientific cruises and 11 AUV missions between 2018 and 2022, resulting in more than 15,000 hydrographic profiles, are collated and presented in the form of four research papers. All data are collected as part of the Nansen Legacy project. Using detailed observations in the region along the continental slope north of Svalbard between 12°E and 24°E, we describe the hydrographic structure, volume transport, and circulation patterns of the warm AW boundary current. The AW volume transport reaches a maximum of 3.0 ± 0.2 Sv in October, with an intraseasonal variability of 1 Sv. The strength of the AW boundary current is sensitive to the wind stress curl, doubling its volume transport in less than a week when the wind stress curl averaged over the region transitioned from strongly negative to strongly positive values. A previously unknown, deep bottom-intensified current is observed to flow parallel to the boundary current, between the 1,500 and 2,000 m isobaths. Historical data in the region support the presence of the bottom-intensified current. The follow-up studies concentrated on the northwestern Barents Sea. Targeted measurements from AUVs offer a step change in the spatial and temporal coverage of observations. To exploit the technology, particularly for turbulence measurements, we explored the potential of a thruster-propelled AUV. We instrumented the AUV with a turbulence sensor package, and using this novel setup, we report on the data quality and discuss the limitations of turbulence dissipation rate estimates from shear probes. The AUV mission in the Barents Sea in winter lasted for 5 h, operating at a typical horizontal speed of 1.1 m/s. The AUV was programmed to find and cross the maximum along-path thermal gradient at 10, 20 and 30 m depths along 4 km transects. Although the AUV vibrations contaminate the shear probe records, the noise is mitigated by removing vibration-induced components from shear spectra using the accelerometer signal. Dissipation estimates from the AUV show good agreement with nearby vertical microstructure profiles obtained from ship, indicating that the turbulence measurements from the AUV are reliable for this relatively turbulent environment. Circulation pathways, hydrography and volume transports of Atlantic- and Arctic-origin waters on the northwestern Barents Sea are explored using data from three cruises and nine glider missions conducted between 2019 and 2022, as well as historical data collected between 1950 and 2009. In particular, we focus on the exchange and dynamics across the thermohaline polar front (PF) region. Our observations show that 0.9 ± 0.1 Sv of Atlantic-origin water reaches the PF region before splitting into several branches and eventually subducting beneath Polar Water (PW). The amount of Atlantic-origin water stored in the basin north of the PF is controlled by the density difference between AW and PW, and reached a maximum in the 90s when PW was particularly fresh. In the recent period from 2019 to 2022, the inflow of AW into the Barents Sea freshened by up to 0.1 g/kg compared to previous decades. This led to an increased temperature gradient across the PF and a reduced poleward transport of warm water. Using data targeted to resolve the dynamics and variability of the PF, we describe the structure of the front, its variability and associated mixing. Ocean stratification, currents, and turbulence data were obtained during seven ship transects across the PF near 77°N, 30°E in fall and winter conditions. These transects are complemented by nine glider missions using ocean gliders, one of which was equipped with microstructure sensors to measure turbulence. Across the front, we observe warm and salty AW intruding below the colder and fresher PW, setting up a baroclinic front and geostrophic currents reaching 25 cm/s, with estimated eastward transport of 0.3 ± 0.2 Sv. Short-term variability below the surface mixed layer arises from tidal currents and mesoscale eddies. While the effects of tidal currents are mainly confined to the bottom boundary layer, eddies induce significant shifts in the position of the front, and alter the isopycnal slopes and the available potential energy of the front. Substantial water mass transformation is observed across the front, likely a result of eddy-driven isopycnal mixing. Despite the seasonal changes in the upper layers of the front (0–100 m) influenced by atmospheric forcing, sea ice formation, and brine rejection, the position of the front beneath 100 m depth remained relatively unperturbed. Collectively, the papers in this thesis have advanced our knowledge about the AW inflow into the Arctic Ocean, its pathways and mechanisms controlling the mixing and distribution of heat from AW to the surrounding Arctic waters. This work represents an important step towards comprehending the influence of AW on the Arctic Ocean, essential for sustainable management and predicting the future of Arctic marine ecosystems.Doktorgradsavhandlin

    Collaborative video editing

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    Samarbeid i videoredigering Denne avhandlingen tar opp følgende spørsmål: Hvordan kan vi støtte samarbeid i videoredigering? I ulike anvendelsesområder, som skriving og design, er bruk av samarbeidsverktøy utbredt. Likevel er programvare for videoredigering i hovedsak utviklet for individuell bruk. Videoredigering bør forstås som en sosial aktivitet og blir i profesjonelle sammenhenger ofte utført som et samarbeid mellom ulike aktører. Basert på intervjuer og designverksteder, undersøker denne avhandlingen hvordan videoredigerere samarbeider og utforsker mulighetsrommet for å støtte samarbeid i videoredigering gjennom design av nye løsninger. I tre studier undersøker denne avhandlingen videoredigering fra tre perspektiver. Først undersøker den samarbeidspraksiser blant profesjonelle videoredigerere og identifiserer ulike strategier og sosiale mekanismer som brukes for å oppnå enighet mellom aktørene som er involvert i videoproduksjon. Denne første studien identifiserer ni temaer som beskriver hvordan videoredigerere håndterer usikkerhet og oppnår enighet, spesielt gjennom organisatoriske mekanismer, dokumentasjon og ikoniske referanser. Studien foreslår også tre ulike retninger for design av nye løsninger for å støtte samarbeid i videoredigering. Det andre studiet undersøker videoproduksjon fra et organisatorisk perspektiv, med fokus på en pågående overgang til distribuert arbeid og dets innvirkning på videoproduksjon. Den andre studien skisserer de kortsiktige og langsiktige implikasjonene av å innføre distribuerte arbeidsformer i TV-produksjonsorganisasjoner under COVID-19-pandemien. Den siste studien ser på samarbeid i videoredigering som et designproblem og presenterer designideer for hvordan man kan støtte et slikt samarbeid. I tillegg peker denne studien på utfordringer som kan være til hinder for innføringen av nye videoredigeringsverktøy som skal støtte samarbeid. Ved å sammenstille resultatene fra de tre studiene, samt analysere tidligere forskning og eksisterende videoredigeringsverktøy, identifiserer avhandlingen tre designtilnærminger for å støtte samarbeid i videoredigeringsprogramvare: holistisk, skreddersydd og konfigurerbar. Selv om disse tilnærmingene diskuteres med tanke på samarbeid i videoredigeringspraksiser, kan de tilby et bredere analytisk rammeverk for å vurdere utformingen av samarbeidsverktøy også for andre anvendelsesområder.This thesis addresses the following question: how can collaboration be supported in video editing? In many domains, such as writing and design, collaborative tools have become common and widespread. However, video-editing software is still predominantly designed for solo users. Nevertheless, video editing is a social activity that, in a professional setting, often involves various people working together. Based on interviews and design workshops, this thesis investigates the collaborative practices of video editors and explores the design space of collaborative video editing. In three studies, this thesis looks at video editing from three angles. First, it investigates the collaborative practices of video editors and identifies the strategies and social mechanisms they employ to reach agreements with various parties involved in the videoproduction process. The first study identifies nine themes that characterise the ways video editors manage uncertainties and reach agreements, particularly through organisational mechanisms, documentation, and iconic referencing. The study also suggests three design paths to explore further. Second, it examines video production from an organisational point of view, focusing on the recent shift towards remote work and its impact on video production. The second study delineates the short-term and long-term implications of adopting remote work in TV production organisations during the COVID-19 pandemic. Third, it approaches collaborative video editing as a design problem and offers design ideas to enhance collaboration. Additionally, it uncovers challenges that might impede the adoption of new collaborative video-editing tools. In synthesising the results of the three studies, as well as analysing previous research and existing video-editing tools, this thesis identifies three design approaches for supporting collaboration in video-editing software: holistic, tailored, and configurable. While discussed in the context of collaborative video editing, these approaches offer a broader analytical framework for considering the design of collaborative production tools.Doktorgradsavhandlin

    "Turning, Turning, Turning" – Movement, immobility and the end of the poem in Frank O'Hara's poetry

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    Abstract: This thesis revolves around figures of movement and immobility in the poetry of Frank O’Hara, and explores such figures in terms of poetic form and structure. Regularly presented as as a quintessentially restless poet, whose work is characterized by movement, speed and energy, the question of immobility and stasis has received less attention in the critical literature on O’Hara. Focusing on the theoretical and formal problem of endings and closure, I discuss the ways in which O’Haras emphasis on process and immediacy creates a tension within his poems that manifests itself as a crisis at the end. By reading such moments of crisis and tension, I explore the various formal and thematic responses that O’Hara’s lyric articulates. Beginning with a reading of the poet in motion, I suggest that O’Hara situates poetic creation in the body’s internal processes, and particularly the breath of the poet. This gesture ties him to a wider discourse on poetic breath in American poetry, that situated poetic form in the immediate existential reality of the body. Moving from breathing to walking, I discuss O’Hara walk poems and questions of poetic form through the idea of a «bodily rhythm» and its relation to a social and economic order. I argue that O’ Haras restless poetry is haunted by the prospect of immobility and figures of death. This leads to an exploration of the meaning of statues in O’Haras poetic imagination. Focusing on the long poem «In Memory of my Feelings», I pursue a reading of the poem’s apotropaic images and, especially, the figure of the Medusa. By tracing its prosodic and formal strategies, I describe the enigmatic character of the poem’s ending. Finally, I discuss the ways in which O’Hara’s poetry foreground problems of endings, focusing on the relation between prose and poetry in the context of his prose poem «Meditations in an Emergency». More generally, I move toward the figure of «turning», and propose this as a way of understanding O’Hara’s relationship to figures of the end. I conclude that the sense of turning in O’Hara’s poetry allows him to mediate between the desire for movement and the fearful prospect of stasis.Allmenn litteraturvitenskap mastergradsoppgaveALLV350MAHF-LIT

    Potential of AI-Driven Chatbots in Urology: Revolutionizing Patient Care Through Artificial Intelligence

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    Purpose of Review Artificial intelligence (AI) chatbots have emerged as a potential tool to transform urology by improving patient care and physician efficiency. With an emphasis on their potential advantages and drawbacks, this literature review offers a thorough assessment of the state of AI-driven chatbots in urology today. Recent Findings The capacity of AI-driven chatbots in urology to give patients individualized and timely medical advice is one of its key advantages. Chatbots can help patients prioritize their symptoms and give advice on the best course of treatment. By automating administrative duties and offering clinical decision support, chatbots can also help healthcare providers. Before chatbots are widely used in urology, there are a few issues that need to be resolved. The precision of chatbot diagnoses and recommendations might be impacted by technical constraints like system errors and flaws. Additionally, issues regarding the security and privacy of patient data must be resolved, and chatbots must adhere to all applicable laws. Important issues that must be addressed include accuracy and dependability because any mistakes or inaccuracies could seriously harm patients. The final obstacle is resistance from patients and healthcare professionals who are hesitant to use new technology or who value in-person encounters. Summary AI-driven chatbots have the potential to significantly improve urology care and efficiency. However, it is essential to thoroughly test and ensure the accuracy of chatbots, address privacy and security concerns, and design user-friendly chatbots that can integrate into existing workflows. By exploring various scenarios and examining the current literature, this review provides an analysis of the prospects and limitations of implementing chatbots in urology.publishedVersio

    The lower airway microbiota and inflammation in chronic obstructive pulmonary disease (COPD) : Thoughts on where to measure it, how to interpret it, and why it might matter

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    Bakgrunn: Kronisk obstruktiv lungesjukdom (KOLS) er ein kompleks, inflammatorisk sjukdom som forårsakar millionar av dødsfall årleg. Bakteriane i dei nedre luftvegane (mikrobiotaet) og immunresponsar kan spele ei viktig rolle i KOLS. Målingar av dei begge kan tenkast å vera påverka av prøvetakingsmetode. Måla med denne oppgåva var å studere KOLS-kohortar med tanke på 1) høve for vekselbruk av indusert og spontant sputum for målingar av inflammasjonsmarkørar og mikrobiota, 2) endringar i inflammasjonsmarkørar og mikrobiota under sjukdomsforverringar samanlikna med stabil sjukdomsfase og 3) forskjellar i mikrobiota i bronkialskyllevæske (BAL) frå pasientar med KOLS samanlikna med friske kontrollar. Metode: Sputum data kjem frå studiane BergenKOLS og tilhøyrande eksaserbasjonsstudie med 433 pasientar med KOLS inkludert, og 356 som vart følgt med tanke på forverringar. BAL data kjem frå studien MikroKOLS med 130 pasientar med KOLS og 103 friske kontrollar inkludert. Inflammasjonsmarkørar i sputum vart målt med bead based multiplex immunoassay og antimikrobielle peptid med enzyme linked immunosorbent assay. DNA sekvensar vart reinska ved hjelp av både enzym og mekanisk lysering. PCR-amplifisering av 16S rRNA og paired-end sequencing med Illumina MiSeq System vart utført. Data vart analysert i QIIME 1&2, Stata og R. Resultat: Inflammasjonsmarkørar og mikrobiota var signifikant forskjellige i indusert og spontant sputum, og i stabil fase av KOLS samanlikna med under pågåande forverring. I høve til sjukdomsfase var ulikskapane heterogene når ein såg på kvart individ. Mikrobiota i BAL var meir ujamn og rikare på Firmicutes hos pasientar med KOLS samanlikna med friske. Kjønn, alder, røyking, sjukdomsgrad og bruk av inhalasjons-kortikosteroider var ikkje tydeleg assosiert til mikrobiotaet i dei nedre luftvegane. Konklusjon: Sputumprøvetaking påverkar målingar av inflammasjonsmarkørar og mikrobiota. KOLS forverringar og KOLS i seg sjølv er begge assosiert med endringar i luftvegsmikrobiotaet. Det tyder på at mikrobiotaet spelar ei rolle i KOLS.Background: Chronic obstructive pulmonary disease (COPD) is a complex inflammatory disease causing the death of millions annually. The lower airway bacterial community (microbiota) and immune responses could be important for the pathogenesis of COPD. The aims for this thesis were to study COPD cohorts considering if measures of inflammatory markers and microbiota 1) are affected by sputum sampling techniques, 2) differ with COPD state, and 3) if the microbiota differ in bronchoalveolar lavage (BAL) comparing patients with COPD with controls. Methods: Sputum data originated from the Bergen COPD Cohort and exacerbations studies in which 433 patients with COPD were enrolled and 356 followed for exacerbations. BAL data originated from the MicroCOPD study in which 130 patients with COPD and 103 controls were enrolled. Inflammatory markers in sputum were measured by a bead based multiplex immunoassay and antimicrobial peptides by enzyme linked immunosorbent assay. DNA sequences were obtained by enzymatic and mechanical lysis extraction methods, PCR-amplification of the 16S rRNA gene and paired-end sequencing using the Illumina MiSeq System. Data were analysed in QIIME 1&2, Stata, and R. Results: Inflammatory markers and microbiota differed significantly between induced and spontaneous sputum, and between stable state COPD and exacerbations. Differences related to disease state showed great heterogeneity looking at individual participants. The microbiota in BAL sampled in the COPD cohort had lower evenness and higher abundances of Firmicutes compared with controls. Sex, age, smoking, disease severity and use of inhaled corticosteroids were not clearly associated with the lower airway microbiota. Conclusion: Sputum sampling methods influences on measurements of inflammation and microbiota. Exacerbations in COPD and the presence of disease are both associated with microbiota dysbiosis which indicate importance of the lower airway microbiota in the pathogenesis in COPD.Doktorgradsavhandlin

    Work-related risk factors for workplace bullying : The moderating effect of laissez-faire leadership

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    Workplace bullying has been described as repeated and systematic exposure to negative social acts over time, which the target has difficulties defending against (Einarsen et al., 2020). Previous research has established that bullying in the workplace is related to a wide range of negative outcomes, and bullying has been classified as a more crippling and devastating problem for employees than all other work-related stress put together (Hauge et al., 2010; Wilson, 1991). Yet, the field still lacks systematic and thorough knowledge of the mechanisms that may explain how situational antecedents are related to the occurrence and development of the workplace bullying process. Drawing on the work environment hypothesis, studies have shown that bullying seems to thrive in demanding workplaces where employees experience organizational constraints and contradictory expectations and demands. Furthermore, leadership practices are expected to have a significant impact on the presence of stress at work. For example, poor and destructive leadership has been identified as a root cause of subordinate stress (Kelloway et al., 2005; Skogstad et al., 2014), and may, as such, act as a strong stressor in its own right. However, leaders may also impact the level of stress at work indirectly, either by influencing the opportunities employees have to cope with those stressors present, or by either aggravating or alleviating the stressors already present in the work environment. The main aim of this PhD-project has been to improve our understanding of the phenomenon of workplace bullying, by investigating some mechanisms and conditions which allow bullying to flourish and escalate. The present thesis is comprised of three scientific papers, all of which employ self-report questionnaire data. The overreaching research question in all three papers was whether laissez-faire leadership can act as a moderator in the relationship between various prevailing workplace stressors and subsequent experiences of negative acts and workplace bullying. Moreover, Paper 2 examines the role of the inter-relationship between two prevailing role stressors in the development of workplace bullying, by testing the mediating effect of role conflicts in the relationship between role ambiguity and subsequent exposure to bullying behaviours. In addition, Papers 2 and 3 also investigated the potential buffering effect of transformational leadership, a constructive form of leadership that is in stark contrast to laissez-faire leadership. In paper 1, the main objective was to investigate the prospective relationship between co-worker conflict at time 1 and individuals who self-reported as new victims of bullying two years later, and whether this relationship was exacerbated by the individuals’ reports of laissez-faire leadership behaviour enacted by their immediate supervisor. Results from a logistic regression analysis on a representative sample of Norwegian workers (N = 1772) showed a significant positive relationship between conflict with co-workers and subsequent new victims of workplace bullying. Furthermore, the results showed that this relationship was only present for employees who reported high (vs. low) levels of laissez-faire leadership behaviour from their immediate supervisor. Paper 2 had two main objectives. First, we aimed to investigate the mechanisms through which role stressors lead to workplace bullying, by testing the hypothesis that the impact of role ambiguity on employees’ exposure to negative acts is mediated through their experiences of increased levels of role conflicts. Second, we tested whether laissez-faire leadership exacerbated, while transformational leadership attenuated, this relationship. In this study, we employed a national probability sample of 1,164 Norwegian workers, with three measurements across a 12-month period. The results supported our hypotheses, in that the relationship between employees’ role ambiguity and subsequent exposure to bullying behaviours was mediated by an increase in employees’ experience of role conflicts. Moreover, we found that laissez-faire leadership exacerbated, while transformational leadership attenuated, the indirect relationship between role ambiguity and subsequent exposure to bullying behaviours through role conflicts. Finally, the objective of Paper 3 was to test whether it is possible to detect these mechanisms even on a daily basis. Accordingly, this study investigated the day-to-day relationship between employees’ work pressure and their exposure to bullying-related negative acts and tested the hypotheses that even daily levels of laissez-faire leadership exacerbated while daily levels of transformational leadership attenuated this relationship. Using data from a sample of 61 naval cadets, who completed a daily diary questionnaire on 36 consecutive days (N = 1509 daily observations), we tested the day-to-day relationships between work pressure and exposure to bullying-related negative acts, and the moderating effects of daily transformational and laissez-faire leadership. The results of multilevel analyses showed a positive relationship between daily work pressure and daily exposure to bullying-related negative acts, and a positive moderating effect of daily laissez-faire leadership behaviour. More specifically, our analyses showed that the positive relationship between daily work pressure and daily exposure to bullying-related negative acts was only present on days when the subordinates reported higher levels of laissez-faire behaviour from their immediate leader. Finally, we did not find support for a moderating effect of daily transformational leadership behaviour. Taken together, these findings yield support to the theoretical notion of the work environment hypothesis, in that situational stressors represent prevailing risk factors for individuals to be exposed to negative acts and bullying in the workplace (Einarsen et al., 1994; Leymann, 1996). Moreover, our findings support the theoretical assumption that laissez-faire leadership is an important facilitator in the development of workplace bullying. Indeed, our results indicate that laissez-faire leadership may be of greater consequence in exacerbating the bullying process than transformational leadership is in attenuating the negative consequences of workplace stressors. If leaders neglect their inherent responsibility to adequately address employees’ experiences of stressful situations and ongoing interpersonal conflicts that merit attention, the risk of workplace bullying is likely to increase. Furthermore, our results show the same trends across samples and research designs, thereby strengthening the robustness of our findings. Finally, the results from Paper 2 improve our understanding of the inter-relationship between role ambiguity and role conflict in relation to bullying, by supporting the hypothesis that employees’ experience of role conflicts mediates the role ambiguity-bullying relationship. This finding indicates that role conflicts may be the more proximal, while role ambiguity may be a more distal antecedent of workplace bullying.Doktorgradsavhandlin

    The Free Movement of Electricity within the EEA

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    The topic of this thesis is the security of energy supply as a ground for restricting electricity exports within the EEA. The analysis discusses the legal situation after the EEA Agreement and the EU. It seeks to identify if there is a different threshold for the EFTA States and the EU Member States’ flexibility to limit electricity exports. To do so, my thesis discusses how electricity is related to the internal market, what the legal situation currently is within the EFTA pillar (following the Third Energy Package) and the legal situation within the EU pillar (following the Clean Energy Package). My perception is that the threshold for implementing measures restricting electricity exports to secure energy supply is higher within the EU pillar compared with the EFTA pillar.MasteroppgaveJUS399MAJUR-2MAJU

    On self-equivalences of APN functions

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    In this thesis we investigate the structure of what we call extended linear self-equivalences for vectorial Boolean functions. That is, (L1,L2,L)(L_1, L_2, L) such that L1FL2+L=FL_1 \circ F \circ L_2 + L = F for some vectorial Boolean function F, where L1L_1 and L2L_2 are linear permutations and L is a linear function. We implement a parallel version of an algorithm for testing EA equivalence in the programming language Rust. This allows us to compare the performance of implementations in C and Rust for similar problems and to conclude that our Rust implementation is comparable in efficiency while being significantly easier to write and maintain. Using our implementation we calculate the self-equivalences for all known quadratic APN functions up to CCZ equivalence in dimensions 6, 8 and 10. We discover functions with trivial linear self-equivalence, but with nontrivial EL self-equivalences. Based on this we formulate a search procedure for obtaining new APN functions, which exploits extended linear self-equivalences in the same way that the search of Beierle et al. exploits linear self-equivalences. From the initial test runs of our new algorithm we discover that the search allows us to start from a given APN function and find APN functions CCZ-inequivalent to it. More interestingly we observe that the search can even find non-quadratic APN functions.Masteroppgave i informatikkINF399MAMN-PROGMAMN-IN

    Disciplinary Rhetoric: And the Language of Online Rape Culture

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    Mastergradsoppgave i digital kulturDIKULT350MAHF-DIKU

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    University of Bergen is based in Norway
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