Opin vísindi
Opin vísindi er varðveislusafn vísindaefnis og doktorsritgerða í opnum aðgangi á vegum íslenskra háskóla og Landsbókasafns Íslands - Háskólabókasafns.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Nýlega bætt við
Validation of manually scored multichannel frontal electroencephalography against polysomnography in a paediatric cohort
(2025-02-13) Sigurdardottir, Sigridur; Pitkänen, Henna; Korkalainen, Henri; Kainulainen, Samu; Serwatko, Marta; Ólafsdóttir, Kristín Anna; Sigurðardóttir, Sigurveig Þ; Clausen, Michael Valur; Somaskandhan, Pranavan; Stražišar, Barbara G; Leppänen, Timo; Arnardóttir, Erna Sif; Department of Engineering
Polysomnography is the only internationally recognized method to diagnose paediatric obstructive sleep apnea, thus, simpler and more cost-effective diagnostic tools are urgently needed. This study aimed to validate the manual scoring of frontal self-applicable electroencephalography against polysomnography in a paediatric cohort. The polysomnography and the frontal electroencephalography were simultaneously recorded for 1 night (n = 102) in 10-13-year-old children. Scoring was performed according to the American Academy of Sleep Medicine rules, with minor adjustments to the frontal electroencephalography. Manual scorings of sleep stages were compared in an epoch-by-epoch manner using Cohen's kappa (κ) and confusion matrices using three different models: the three-stage (wake/non-rapid eye movement/rapid eye movement), the four-stage (wake/sleep stage 1 + sleep stage 2/deep sleep Stage 3/rapid eye movement) and the five-stage model (wake/sleep stage 1/sleep stage 2/deep sleep Stage 3/rapid eye movement). The inter-scorer agreements were assessed, and the intraclass correlation coefficient was used for common sleep variables: total sleep time, wake after sleep onset, sleep efficiency, sleep-onset latency and arousal index. Cohen's κ values for the three-stage, four-stage and five-stage models were 0.85, 0.73 and 0.70, respectively. The agreement for the sleep variables studied ranged from 0.87 to 0.99. The inter-rater agreement (n = 10) was κ = 0.78 for the polysomnography and κ = 0.70 for the frontal electroencephalography. Sleep staging from the frontal electroencephalography was comparable to that of a standard polysomnography in a paediatric cohort, and showed promising results in estimating sleep time and sleep architecture.
Melanoma dedifferentiation enhances IFNγ responses and reduces cytotoxic T cell activity
(University of Iceland, School of Health Sciences, Faculty of Medicine, 2026-09) Sævarsson, Teitur; Berglind Ósk Einarsdóttir; Faculty of Medicine (UI); Læknadeild (HÍ); School of Health Sciences (UI); Heilbrigðisvísindasvið (HÍ)
Cutaneous melanoma is a deadly skin cancer arising from epidermal melanocytes. A defining feature of melanoma cells is their ability to reversibly dedifferentiate in response to cellular stress, largely through loss of the transcription factor MITF. Dedifferentiation is associated with reduced melanocytic antigen expression, increased migratory and invasive capacity, altered responses to inflammatory stimuli, e.g. leading to increased IFNγ-induced PD-L1 expression. This indicates that melanoma dedifferentiation may influence anti-tumor immune responses and contribute to immune evasion. In this thesis, the effects of melanoma dedifferentiation on immunomodulatory gene expression and melanoma-T cell responses were investigated.
The effects of dedifferentiation on immunomodulatory gene expression were assessed by siRNA mediated knockdown of MITF expression in 624Mel cells followed by IFNγ stimulation. Transcriptomic and epigenetic effects were assessed via RNA-seq and ATAC-seq, respectively. IFNγ-induced PD-L1 expression following MITF knockdown was evaluated in 624Mel, SK-MEL-28, A357P, Malme-3M and B16 melanoma cells by qPCR and western blotting. Small molecular inhibitors against the JAK kinases, STAT3 and NFκB and siRNAs targeting STAT1 and IRF1 were used to investigate PD-L1 regulation in 624Mel cells. Public RNA-seq data from patient-derived melanoma cell lines were analyzed to validate the broader relevance of the results. Co-cultures were performed using TCR-redirected T cells and GFP expressing melanoma cell lines at varying differentiation states in live-cell imaging assays. Cytokine secretion in the co-cultures was quantified using a Luminex assay.
The results showed that dedifferentiation predisposes melanoma cells to IFNγ signaling through rearrangements in chromatin accessibility, resulting in widespread expression of immunomodulatory genes. PD-L1 expression in dedifferentiated 624Mel cells was mediated via the canonical JAK-STAT1-IRF1 pathway and accompanied by a significant increase in IRF and STAT transcription factor motif accessibility. Co-cultures of TCRredirected T cells and melanoma cell lines suggest that differentiation state does not impair antigen processing and presentation. However, the rate of cytotoxic T cell responses was reduced by IFNγ pre-treatment of either highly differentiated or undifferentiated melanoma cell lines, and by induced dedifferentiation via MITF knockdown. T cell derived secretomes following culture with undifferentiated melanoma cells contained less TNFα, Granzyme B, CXL10, MIF and CCL5 than when cultured with differentiated cells, while containing more PD-L1, IL-8, CD25 and IL-6, suggesting decreased T cell activation. In conclusion, melanoma dedifferentiation may directly mediate immunosuppression.
Holographic Models of Emergent Spacetime
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2026) Mohan, Vyshnav; Lárus Thorlacius; Faculty of Physical Sciences (UI); Raunvísindadeild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
Black holes are exceptional laboratories where the apparent incompatibility between gravity and quantum mechanics can be sharpened. In this thesis, quantum features of black holes are probed using the holographic principle, with tools from quantum information and algebraic quantum field theory. Operator algebras provide a natural framework for studying gravity as an emergent phenomenon, and we identify sufficient conditions for the emergence of gravitational dynamics. Going in the opposite direction, quantum gravity effects in an eternal black hole can be modelled by adding certain non-perturbative quantum corrections to its semiclassical operator algebra. This leads to an approximate type I von Neumann algebra whose dimension is equal to the exponential of the Bekenstein-Hawking entropy with logarithmic corrections. Non-perturbative corrections also lead to the late-time saturation of holographic complexity, defined as the volume of a codimension-one extremal surface passing through the black hole interior. A second law associated with this complexity is used to establish a black hole singularity theorem. Non-perturbative corrections may become important during gravitational collapse. Black shells, which have been proposed as an alternative endpoint of collapse in string theory, are studied from a thermodynamic perspective and shown to be thermodynamically favoured over black holes for a range of temperatures.
Ljós og skuggar í sögulegri sagnagerð Madame de Lafayette eða hin ósagða saga um greifann af Tende
(Hugvísindastofnun Háskóla Íslands, 2025-05-06) Kristinsdóttir, Guðrún; Mála- og menningardeild; Faculty of Languages and Cultures; Hugvísindasvið (HI); School of Humanities (UI)
Sögulega smásagan Greifynjan af Tende eftir Madame de Lafayette (1634–1693) kom ný-verið út í íslenskri þýðingu í smásagnasafninu Fríða og dýrið. Franskar sögur og ævintýri fyrri alda. Fjallað verður um söguna og hún sett í samhengi við smásöguna La Princesse de Montpensier og sögulegu nóvelluna La Princesse de Clèves eftir sama höfund sem báðar teljast með merkustu bókmenntaverkum sautjándu aldar. Allar sögurnar þrjár gerast við hirðir síðustu Valois-konunganna á tímum trúarbragðastríðanna, um hundrað árum fyrir ritunartíma þeirra. Skáldskaparfræðileg greining á frávikum höfundar frá sögulegum staðreyndum leiðir í ljós að eitt af því sem fyrir skáldkonunni hefur vakað, hefur verið að minnast kvenna sem dæmdar höfðu verið til gleymsku og afreka sem kenna mætti við borgaralega óhlýðni.
Whale ecosystem services and co-production processes underpinning human wellbeing in the Arctic: case studies from Greenland, Iceland and Norway
(Springer Nature, 2020-10-31) Malinauskaite, Laura; Davíðsdóttir, Brynhildur; Cook, David; Ögmundardóttir, Helga; Hagfræðideild; Faculty of Economics; Félagsvísindasvið (HÍ); School of Social Sciences (UI)
The concept of ecosystem services (ES) has only just begun to be applied in the Arctic, and to an even lesser extent to marine mammals, such as whales. This chapter develops an ES cascade model and related ES co-production processes as they apply to whale resources in the Arctic. The result is a new conceptual model demonstrating the interconnectedness of social-ecological processes involving natural and human capital that enhance human wellbeing through the co-creation of whale ES. An ES cascade model is presented for whale ES, which connects the five linked stages of such ES production: the biophysical structure, functions, ecosystem services, the benefits to human wellbeing, and associated values. They are further expanded to include the co-production processes of whale ES as well as its main stages, inputs, and flows. These processes are illustrated using examples from ARCPATH case studies of coastal communities dependent on whale resources: Húsavík in Iceland, Andenes in Norway, and Ilulissat/Disko Bay in Greenland. The chapter aims to im-prove the understanding of the human dimensions of ES and the underlying processes that enable Arctic coastal communities to benefit from whales. It provides a starting point for further analysis of possible research and management approaches regarding whale resources in the Arctic.
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