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Development of AsymPol- and bTurea-Derived Bis-Nitroxides for DNP-Enhanced NMR in Biological Systems
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2026-06-16) Wilson, Ancy Trisha; Snorri Þór Sigurðsson; Faculty of Physical Sciences (UI); Raunvísindadeild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
Dynamic nuclear polarization (DNP)-enhanced solid-state nuclear magnetic resonance (NMR) spectroscopy has emerged as a powerful technique to unravel complex biomolecular structures at atomistic resolution. DNP serves to overcome the inherent insensitivity of NMR by the polarization transfer from unpaired electrons to nuclei of interest under microwave irradiation. The sensitivity gain conferred by DNP enables the detection of biomolecules at their physiological concentration. Nitroxide biradicals have shown to be excellent polarizing agents at 9.4 T and 14.1 T, prompting our interest in utilizing them to investigate complex systems via DNP-NMR. However, their broader applicability is limited by several factors, including synthetic challenges, lack of specificity, poor aqueous solubility, and rapid reduction in a reducing environment. This thesis describes the development of synthetic strategies for nitroxide-based biradicals to address these limitations. Firstly, a series of AsymPol-derivatives, including an isothiocyanate, a tetrazine, a maleimide, a cholesterolbased tripod, and an azide, was synthesized to enable targeting of diverse systems ranging from biomolecules to materials. These radicals enabled targeted DNP, which allows selective enhancement of signals from specific sites. Secondly, bTurea-derived bcTCOOKs and bcTmols were developed as readily accessible and water-soluble derivatives to address synthetic limitations associated with highly performing bis-nitroxide biradicals. Among these, bcTCOOK-M2 was the highest yielding and exhibited particularly high DNP sensitivity. Finally, a synthetic strategy was established for highly water-soluble, reductionresistant nitroxide radicals (43 and 44) for in-cell DNP applications. Their stability in the presence of ascorbic acid was evaluated and compared with known radicals; however, they did not exhibit sufficient stability under reductive conditions.
Verk
An infant diet score, BMI and asthma medication in childhood; Population-based evidence from the Icelandic Maternal and Child Health Study (ICE-MCH).
(University of Iceland, School of Health Sciences, Faculty of Food Science and Nutrition, 2026-06) Jonsdottir, Jenny; Birna Þórisdóttir og Inga Þórsdóttir; Faculty of Food Science and Nutrition (UI); Matvæla- og næringarfræðideild (HÍ); School of Health Sciences (UI); Heilbrigðisvísindasvið (HÍ)
Background and aim: Infant nutrition is a key determinant of both short- and long-term health. However, few population-based studies have integrated information on breastfeeding and complementary feeding into a comprehensive measure and examined its associations with childhood health outcomes. The aim of this doctoral thesis, “An Infant Diet Score, BMI, and Asthma Medication in Childhood: PopulationBased Evidence from the Icelandic Maternal and Child Health Study (ICE-MCH)”, was to investigate associations between infant nutrition, childhood BMI, and pediatric asthma medication use. Materials and methods: The ICE-MCH study includes data from electronic health registers for children born in Iceland between 2009 and 2015, forming a nationwide population-based cohort (N=30,623). Paper I of the thesis describes infant nutrition from a few weeks after birth until one year of age. Nutritional variables were obtained from records completed by primary healthcare nurses during nine routine visits with the infant and their caregiver, most often the mother. A composite measure of infant nutrition quality, the Infant Diet Score (IDS), was derived from these data, based on Icelandic infant feeding recommendations and existing infant diet scores. The IDS comprised six components: duration of exclusive and any breastfeeding, age at introduction of cow’s milk and complementary foods, an estimate of dietary variety, and use of vitamin D supplementation. Higher scores indicated greater adherence to infant nutrition guidelines. Associations between the IDS and growth outcomes were examined, with a focus on the international BMI-for-age z-scores during infancy and toddlerhood (12 and 18 months; Paper I) and childhood (2.5, 4, 6, and 9 years; Paper II). Associations between the IDS and asthma medication between ages 1 and 7 years were investigated using data from the Icelandic Prescription Medicines Register. The outcome was defined as two or more dispensations of asthma medication within a 12- month period (Paper III). In addition to descriptive analyses, linear and logistic regression models were applied, both unadjusted and adjusted for potential confounders. Results: Due to its composite nature, the IDS was calculated for the subset of children with complete nutritional data across all nine visits from 0 to 12 months of age (n = 12,848). Findings from Papers I–III showed that greater adherence to infant nutrition guidelines, reflected by a higher IDS, was associated with more favorable BMI trajectories up to 9 years of age and a lower risk of asthma medication use up to age 7. Children in the lowest IDS quintiles had higher odds of overweight and obesity (based on international definitions) at 12 and 18 months and at 6 and 9 years compared with those in the highest quintile, after adjustment for relevant maternal and birth characteristics. When examining individual components of the score, most consistently shorter duration of exclusive and any breastfeeding were associated with less favorable growth outcomes. Shorter duration of exclusive and any breastfeeding, lower use of vitamin D supplementation, and lower overall IDS were consistently associated with increased odds of having two or more asthma medication dispensations within a 12- month period between ages 1 and 7 years. Conclusions: This study demonstrates that the Infant Diet Score, a composite measure capturing overall diet quality during the first year of life, is a valuable population-based indicator of infant nutrition that can be applied in research on health outcomes. Lower adherence to infant nutrition guidelines in the first year of life is associated with less favorable growth trajectories and increased asthma medication dispensation in childhood. These findings suggest that infant nutrition is an early-life exposure that is important for subsequent child health.
Verk
Réttindi og þátttaka barna : Samstarfsverkefni í leikskólum, á yngsta stigi grunnskóla og á frístundaheimilum Hafnarfjarðarbæjar
(RannUng, 2026-06-09) Hreinsdóttir, Anna Magnea; Björnsdóttir, Margrét Sigríður; Ólafsdóttir, Sara Margrét; Deild kennslu- og menntunarfræði
Skýrslan fjallar um samstarfsverkefnið Réttindi og þátttaka barna sem RannUng og Mennta- og lýðheilsusvið Hafnarfjarðarbæjar unnu með leikskólum, yngsta stigi grunnskóla og frístundaheimilum á árunum 2023–2026. Markmið verkefnisins var að innleiða Barnasáttmála Sameinuðu þjóðanna markvisst í daglegt starf, efla þekkingu starfsfólks, barna og foreldra á réttindum barna og skapa aðstæður þar sem börn geta haft raunveruleg áhrif á eigið skóla- og frístundalíf. Verkefnið byggði á starfendarannsóknum, fræðslu, sameiginlegum fundum, rýnihópaviðtölum og þróun verkefna á hverri starfsstöð, meðal annars um lýðræði í hópastarfi, áhugasviðsval, bókasafn, matartíma og valkerfi í frístund. Niðurstöður sýna að þekking starfsfólks á réttindum barna jókst og varð víða samofin daglegum starfsháttum. Viðhorf til barna þróuðust frá því að líta á þau sem þátttakendur innan fyrirfram ákveðins ramma yfir í að viðurkenna þau sem virka gerendur með eigin sjónarmið og áhrif. Dæmin sýna að þátttaka verður merkingarbær þegar hugmyndir barna eru teknar áfram og leiða til sýnilegra breytinga. Helstu áskoranir tengdust tíma, mannafla, forföllum, ólíkum þörfum barna og togstreitu milli verndar og sjálfræðis. Verkefnið sýnir að innleiðing Barnasáttmálans krefst ígrundunar, skýrrar ábyrgðar, stuðnings stjórnenda og þess að réttindi barna verði hluti af starfsmenningu en ekki viðbótarverkefni. Það veitir jafnframt öðrum starfsstöðvum gagnlegan vegvísi til sambærilegrar þróunar og innleiðingar.
Verk
On seismic behavior and vulnerability of building structures: Dynamic identification, condition assessment, and fragility modeling
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Civil and Environmental Engineering, 2026-06-10) Gautam, Dipendra; Rajesh Rupakhety, Bjarni Bessason, Hugo Rodrigues; Faculty of Civil and Environmental Engineering (UI); Umhverfis- og byggingarverkfræðideild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
Structures undergo various changes during their service life due to deterioration or external loading. These changes are the keys to design, assess, and predict structural behavior. The three pillars of structural engineering are the most governing factors to justify safety, serviceability, functionality, and operability of structures, considering forms and functions. Although independently extensively studied, coordinated efforts have not been widely practiced in structural engineering, starting from characterization to condition assessment and finally probabilistic response depiction. Aiming at coordinated dissemination of the three pillars, the present study performs system identification based modal characterization to develop period-height relationships and condition assessment under no external loading, structure undergoing deterioration, changed state of structure due to extreme loading, changed state of structure due to construction progression, and strengthened structures following various states of damage. Furthermore, many sets of seismic fragility functions have been developed for low-rise RC buildings, considering global and component level performance using empirical data. This study covers RC and stone and brick masonry buildings for dynamic identification, condition assessment, and seismic vulnerability modeling. Experimental and empirical approaches have been deployed to estimate dynamic characteristics as structural performance signatures, evolution of dynamic characteristics as signatures of changed state of the structures, and probabilistic models as signatures to quantify the exceedance probability of particular damage level in buildings and components under seismic excitation. Bayesian modeling based formulation is adopted through MCMC using Metropolis-Hastings sampling to derive period-height relationships and fragility functions. Subsequently, posterior parameter uncertainties have also been characterized.
Verk
Computational reconstruction of non-crossover recombination
(2026-05) Harðarson, Marteinn Þór; Halldórsson, Bjarni Vilhjálmur; Department of Engineering
As a diploid organism, humans inherit two copies of each autosomal chromosome, one from the father and one from the mother. The copy of a chromosome transmitted by a parent is reshuffle, via meiotic recombination, of the two parental copies through meiotic recombination. Most apparent are large chromosome parts of alternating chromosomal origin separated by crossover recombination. The other type of meiotic recombination is gene conversion, small segment of one of the parental homologous chromosomes on the background of the other. Gene conversions arise through process called non-crossover recombination (NCO). Recombinations can only be detected indirectly in offspring, at heterozygous markers, sites where the two homologous chromosomes differ. Sequencing errors, genotyping errors, phasing errors and structural variations can all mimic the signature of gene conversions making them difficult to be detected reliably. Not all NCOs create gene conversions, due to their short span and limit number of heterozygous markers. Large NCOs have a better chance to generate gene conversion than short NCO, due to higher likelihood of overlapping heterozygous markers. This makes it difficult to infer information about NCOs from gene conversions. This thesis makes three main contributions. First, three-generation families are used to find and verify gene conversions showing age and sex dependent patterns for these events. Second, a statistical framework modelling the underlying NCO processes generating these gene conversions is developed in order to obtain the underlying length distribution and their quantity. Finally, combining crossovers and non-crossover recombinations to construct a complete human recombination map revealing their contribution to de novo mutagenesis.

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