Opin vísindi

 

Nýlega bætt við

Verk
Grýla in Sléttuhlíð
(2013) Parsons, Katelin Marit; Faculty of Icelandic and Comparative Cultural Studies
Grýlukvæði frá Sléttuhlíð í Skagafirði er varðveitt í tveimur handritum frá síðara hluta 17. aldar auk fjölda yngri handrita. Í útgáfu Ólafs Davíðssonar frá árinu 1903 er kvæðið eignað séra Guðmundi Erlendssyni frá Felli í Sléttuhlíð (um 1595–1670). Þessi útgáfa gefur þó óljósa mynd af varðveislu kvæðisins og styðst lítið við elsta handritið, AM 147 8vo, sem Ólafur kallar „brot.“ Í handritinu reynist uppskriftin vera heil en hún inniheldur gerð kvæðisins sem er með öðru sniði en finnst í yngri handritum. AM 147 8vo liggur til grundvallar nýrri útgáfu af þessu grýlukvæði sem birtist í greininni. Færð eru rök fyrir því að kvæðið sé það sama og grýlukvæði eignað Ásgrími Magnússyni (d. 1679) sem Jón Samsonarson taldi vera týnt. Grýlukvæðið mun hafa verið ort um 1640 en ómögulegt er að fullyrða um höfund kvæðisins, enda var Ásgrímur mágur Guðmundar og bjó í næsta nágrenni í Höfða á Höfðaströnd. Kvæðið er vísbending um náin tengsl milli Guðmundar og Ásgríms og undirstrikar mikilvægi fjölskyldusambanda í íslensku bókmenntalífi 17. aldar.
Verk
Gravity, Holography and Deformations
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2026) Nix, Alexia; Friðrik Freyr Gautason (main advisor), Valentina Giangreco M. Puletti (administrative advisor); Faculty of Physical Sciences (UI); Raunvísindadeild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
In this dissertation we aim to explore gravity using two different methods, namely precision holography and stress-tensor deformations. From the holographic perspective we achieve this by studying the holographic dual of the half-BPS Wilson loop operator, in a variety of both conformal and non-conformal field theories, which is given by the partition function of a fundamental string or probe M2-brane in the corresponding dual geometry. We do this by focusing on the first subleading correction of the corresponding holographic expansion. This way we provide new quantitative tests of these gauge/gravity dualities, and we further develop the tools that are necessary for such an analysis. On the other hand, we utilize the massive gravity formulation of stress-tensor deformations to establish new connections with various theories of gravity, as well as mathematics. In particular, using this formulation we construct a new d-dimensional deforming operator that extends the findings of previous holographic studies, and makes contact with earlier results of minimal massive gravity. In three dimensions, we study the stress-tensor deformation of a certain seed theory and recover the DBI action of a two-brane in Polyakov form as the deformed action, establishing a new connection to string theory. Finally, restricting our analysis to two dimensions we show how the study of some deformed theories, that satisfy certain properties, can lead to further insights regarding the algebraic properties of special functions.
Verk
Irrelevant deformations, relevant masses
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2026) Tsolakidis, Evangelos; Valentina Giangreco and Marotta Puletti; Faculty of Physical Sciences (UI); Raunvísindadeild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
The study of stress-tensor deformations is a newly-formed subfield in high energy theoretical physics and one of its main goals is to map out the space of all quantum field theories. Considering their connection to ghost-free massive gravity via the seminal example of TT in two dimensions, we develop a purely gravitational formalism for any deformation of this family in any dimension. Our approach indicates that the effect of the deformation reduces to coupling the undeformed theory with a carefully constructed mass term for the graviton. We employ this idea in various scenarios retrieving and extending known results in string theory and mathematics, ending up in higher dimensions where the dynamics are less explored. There, we establish a concrete connection between a ghost-free massive gravity theory and a holographically inspired deformation providing in parallel a direct derivation of the Polyakov form for branes in static gauge, based on the corresponding structure of the deformation.
Verk
Stillbirth in Iceland: Causes and clinicopathological phenotypes
(University of Iceland, School of Health Sciences, Faculty of Medicine, 2026-08-04) Bjarnadóttir, Ragnheiður; Jóhanna Gunnarsdóttir; Faculty of Medicine (UI); Læknadeild (HÍ); School of Health Sciences (UI); Heilbrigðisvísindasvið (HÍ)
Aims: to explore the stillbirth rate (SBR) and examine the etiology of stillbirth in Iceland from 1996-2021 as well as review the placental histopathology. Methods: Clinical information was obtained from medical records of mothers who had stillbirths and their infants (n=395). Infants were divided into groups according to gestational age (GA) at diagnosis of stillbirth: early preterm: ≥22 but < 28 weeks (n=140), late preterm: ≥28 but <37 weeks (n=130) and term: ≥ 37 weeks (n=125). Autopsy records and gross description of placenta were reviewed and microscopic slides re-evaluated and classified according to the Amsterdam placental workshop consensus into four major patterns of placental injury. Primary and associated causes of death were assigned according to the Stockholm classification of stillbirth. The SBR, maternal and fetoplacental characteristics, placental histopathology as well as cause of death were compared between two 13-year periods (1996-2008 and 2009-2021) and between GA groups. Chi-square tests were applied and p-level of 0.05 considered statistically significant. Results: The SBR decreased from 4.10 to 2.88/1000 births (p=0.009) between the former and latter period, but the reduction was limited to stillbirths diagnosed before term. Fewer stillbirths in the latter period were attributed to causes such as infection and placental abruption as well as unknown/unexplained. The most common primary causes of stillbirth were reduced circulation in the umbilical cord (25.6%) and placental insufficiency (25.2%); both increased with advancing GA. Despite no difference in proportion of small for gestational age infants between the two periods, placental weight <10th percentile for GA was significantly more common in the latter period than the earlier (30.3% vs 21.3%, p= 0.002), when a larger proportion of stillbirths was attributed to placental insufficiency (37.0 vs 17.0%, p=0.0002). The stillbirth rate at term was 1.18/1000 term infants with no decrease between the two periods. In stillbirth at term, placentas weighing under the 10th percentile were more common in the latter (43.5 vs 31.7%, p<0.05). Chronic villitis of unknown etiology (VUE) was significantly more often diagnosed in the latter period (40.3 vs,12.7%, p<0.01. Cord complications and placental insufficiency were the most common causes of stillbirth at term as 72% (91/125) of deaths were attributed to these causes, either alone or together. Compared to the earlier period, stillbirth was significantly more often attributed to placental insufficiency (with or without cord complications) in the latter compared to the earlier (56.5% vs. 22.2%, p<0.001). Placental histologic slides were reviewed for 96.4% stillborn singletons and classified into four major patterns of placental injury. Maternal vascular malperfusion (MVM) was diagnosed in 19.0%, fetal vascular malperfusion (FVM) in 31.6%, acute chorioamnionitis (ACA) in 32.2% and VUE in 15.9%. More than one pattern of placental injury was found in 7.7% and none of the major patterns in 27.9% of placentas. A similar proportion of MVM was seen in all GA groups, FVM was more common ≥28 weeks whereas ACA was most frequent <28 weeks and VUE most often diagnosed at term. A higher proportion of maternal vascular malperfusion was found in stillbirths with small for gestational age (SGA) infants than non-SGA (23.0 vs 6.1%) as well as in stillbirths with maternal hypertensive disorder of pregnancy than in stillbirths with a normotensive mother (23.9 vs 11.8%). The umbilical cord was classified as at risk in half (53.8%) of singleton stillbirths, the proportion increased with gestational age (28.9% <28 weeks, 56.0% ≥28 but <37 and 71.7% at term). Hypercoiled, excessively long and wrapped cords were most common. Term stillbirths with cord at risk often also had placental MVM and/or VUE. Conclusions: The SBR decreased in the latter period due to a reduction in preterm stillbirth but the SBR at term was unchanged. Reduced circulation of the umbilical cord and placental insufficiency were the commonest causes of death, both increasing with gestational age. Stillbirth due to infection and placental abruption as well as unexplained stillbirths decreased during the study period whereas deaths attributed to placental insufficiency became more common, reflecting lack of reduction of stillbirth at term in the latter period. Stillbirths with VUE and FVM, as well as umbilical cord at risk, were more common with advancing GA and often without recognized risk factors. Understanding major patterns of placental injury and their correlation to clinical phenotypes of stillbirth is valuable when counselling after stillbirth and planning surveillance of a subsequent pregnancy.
Verk
Professional Knowledge in Transition: Police Education Reform and the Reconfiguration of Knowledge in Icelandic Policing
(University of Iceland, School of Education, Faculty of Education and Diversity, 2026-08) Bragason, Olafur Orn; Guðrún Geirsdóttir og Ingólfur Ásgeir Jóhannesson; Faculty of Education and Diversity (UI); Deild menntunar og margbreytileika (HÍ); School of Education (UI); Menntavísindasvið (HÍ)
This doctoral thesis examines how Iceland’s 2016 police education reform reconfigured the forms, value, and legitimacy of professional knowledge as basic police education was shifted from a vocational model to a university-based programme. The reform formed part of a wider professionalisation process with the intention to strengthen the police’s analytical, ethical and communicative competence so that officers are better equipped to respond to an increasingly complex policing environment. Using the analytical perspectives of Shulman, Eraut and Chan, the thesis examines how different forms of knowledge are produced, valued and rendered legitimate across policy, educational and workplace settings. The research comprises four interrelated studies using a multi-method, multi-level design combining qualitative and quantitative approaches: (I) a historical discourse analysis of the policy and legislative texts that framed the reform; (II) an institutional analysis of the implementation of flexible learning and its relationship to workforce needs, access to education, and the system-level legitimation of the reform; (III) a longitudinal study of students’ valuations of professional competence before and after police education reform; and (IV) qualitative interviews with newly graduated officers examining how professional knowledge is enacted and legitimised in practice. The findings suggest that the reform achieved institutional alignment with higher education, but that epistemic and cultural change unfolded more slowly. At the policy level, legitimacy was built on both technocratic and professionalising logics; at the educational level, police students in the university-based programme placed greater value on analytical and relational competence than students in the earlier vocational model; and at the workplace level, academic and experiential knowledge remained only partially integrated. The thesis conceptualises these processes as part of a multi-level knowledge formation in policing and uses the concept of comprehensive competence to describe the cognitive, ethical, and relational dimensions of professional practice. The study contributes to international debates on professional education by portraying how reforms in a small state illuminate the complex interplay between institutional change, learning cultures, and the evolving legitimacy of professional knowledge.

Flokkar í Opnum vísindum

Veldu flokk til að skoða.

Niðurstöður 1 - 9 af 9

Öll gögn í Opnum vísindum eru vernduð af ákvæðum höfundalaga og með öllum réttindum áskildum, nema annað sé tekið fram.