Greinar- HÍ

Varanleg URI fyrir þennan undirflokkhttps://hdl.handle.net/20.500.11815/57

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Niðurstöður 1 - 20 af 1808

Stærðfræði og tónlist
(Félag raungreinakennara, 1992) Kristín, Bjarnadóttir; Menntavísindasvið (HÍ); School of Education (UI)
Stærðfræði teygir sig inn á mörg svið daglegs lífs. Hlutverk hennar í viðskiptum og tækni er alþekkt, en færri vita að stærðfræðileg lögmál leynast í myndlist og tónlist. Í þessari grein verða rakin ævaforn tengsl tónlistar og stærðfræði.
The Library at Bræðratunga: Manuscript Ownership and Private Library-Building in Early Modern Iceland
(2023) Parsons, Katelin Marit; Stofnun Árna Magnússonar í íslenskum fræðum (HÍ); The Árni Magnússon Institute for Icelandic Studies (UI); Hugvísindasvið (HÍ); School of Humanities (UI)
Library institutions did not exist in early modern Iceland, meaning that private ownership was central to the preservation of pre-modern manuscripts and literature. However, personal collections are poorly documented in comparison to the activities of manuscript collectors such as Árni Magnússon. This article examines the case study of Helga Magnúsdóttir (1623–1677) and book ownership at her home of Bræðratunga in South Iceland, concluding that Helga Magnúsdóttir engaged in library-building as a social strategy following the death of her husband, Hákon Gíslason (1614–1652). The inventory of the Bræðratunga estate from 1653 includes only four books, all printed. However, nine manuscripts are conclusively identified as having been at Bræðratunga at least briefly during the period from c. 1653 to 1677, and evidence for the presence of another five items is discussed. Examination of surviving volumes suggests that Helga’s goal was to participate in an active culture of sharing manuscript material across distances, rather than to accumulate a large stationary collection of printed books and codices for Bræðratunga. She thereby played an important but easily overlooked role in the survival of Old Norse–Icelandic literature in the early modern period. Of the manuscripts at Bræðratunga, at least two likely came from Helga’s childhood home of Munkaþverá in North Iceland, the former site of a Benedictine monastery. Her cousin Bishop Brynjólfur Sveinsson of Skálholt (1605–1675) also gifted books to Helga and her family, and on his death she inherited half of his collection of Icelandic books and manuscripts, making her the owner of one of the most significant collections of Icelandic manuscripts in the country. The survival of books from Helga’s library was negatively impacted by the Fire of Copenhagen in 1728, the extinction of her family line in the eighteenth century as a long-term consequence of the 1707–1709 smallpox epidemic and collector Árni Magnússon’s antagonistic relationship with two of her children’s heirs. Árni’s relationship with Oddur Sigurðsson (1681–1741), Helga’s grandson and last living descendent, did eventually improve; an appendix includes a list of manuscripts that Oddur loaned to Árni and may have come from the library at Bræðratunga.
Collective identity, solidarity, and sisterhood in the ASAB cleaning women’s strike in Sweden and the Women’s Day Off in Iceland
(Informa, 2023-06-22) Pálmadóttir, Valgerður; Johansson-Wilén, Evelina; Schmitz, Eva; Sagnfræði- og heimspekideild (HÍ); Faculty of History and Philosophy (UI); Hugvísindasvið (HÍ); School of Humanities (UI)
In recent years feminist movements have increasingly employed the form and rhetoric of strikes in framing their protests. The rise of the women’s strike movement has been seen as an indicator of an invigorated wave of feminist activism that focuses, to a greater extent, on structural economic injustices. The aim of this article is to provide a historical aspect to the growing research on strikes as a multifaceted form of protest. The article analyses articulations of collective identity, solidarity, and sisterhood in two different kinds of ‘women’s strikes’ that took place in the Nordic region during the mid-1970s; the ASAB cleaners’ strikes in Sweden during 1974–1975 and the Icelandic Women’s Day Off that took place on October 24, 1975. The article explores how the relationship between gender and class was conceptualized by participants, organizers, and bystanders. We employ these cases to study how solidarity and sisterhood across differences among women might have appeared in practice while at the same time reflecting internal tensions and varying interests. Moreover, the article reflects on the specific form of the strikes and the potential impact their respective form might have had on the political articulations that came out of them.
The COVID‐School and Social Responsibility: Creative Expressions of Children's Rights and Agency in Iceland During the Pandemic
(Wiley, 2025-03-25) Jörgensen, Eva; Benediktsdóttir, Signý Björk; Nordal, Salvör; Gunnlaugsson, Geir; Einarsdóttir, Jónína; Félagsfræði-, mannfræði- og þjóðfræðideild (HÍ); Faculty of Sociology, Anthropology and Folkloristics (UI); Félagsvísindasvið (HÍ); School of Social Sciences (UI)
This study examines children's experiences in Iceland during the COVID-19 pandemic through their creative expressions sub-mitted to the Ombudsman for Children. Analysing 454 submissions, including narratives, drawings and videos from childrenaged 6–16, the research identified two main themes: the ‘COVID- School’ addressing educational disruptions and peer relation-ships, and ‘Social responsibility’ reflecting children's engagement with health measures. Using Spray's framework of embodied,social and public child dimensions, the study reveals how children navigated pandemic restrictions while demonstrating remark-able health literacy and social consciousness. The findings emphasise children's agency and the importance of including their perspectives in public health crisis responses
The tale of the founder founder: assessing the origin of a recently established fish in Icelandic waters
(Springer Nature, 2025-03-10) Henke, Theresa; Pálsson, Snæbjörn; Hemmer-Hansen, Jakob; Thorlacius, Magnús; Ólafsdóttir, Guðbjörg Ásta; Líf- og umhverfisvísindadeild (HÍ); Faculty of Life and Environmental Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
The geographic origin of an alien species is an important aspect of a species’ invasion history 55 used for classification and management plans but can additionally deliver information on 56 introduction pathways that require the attention of managers and scientists. The invasion 57 history of European flounder (Platichthys flesus), an alien flatfish species first documented in 58 Icelandic waters in 1999, has not been fully elucidated. There have been different hypotheses 59 on the European flounder’s origin and introduction pathway, suggesting either a potentially 60 natural arrival from the Faroe Islands or an introduction via ballast water from the coasts of 61 northwestern Europe. To clarify the geographic origin of European flounder found in Iceland, 62 we used microsatellite analysis of purposefully collected samples from 14 sites around Iceland 63 and reference data stemming from previously published research of flounder population 64 structure in the Faroese and other European populations. Our results indicate that the Faroese 65 population is the most likely source of the European flounder found in Iceland. There was 66 weak IBD between Icelandic samples and the Faroese population. Additionally, we identified 67 9 hybrids between alien European flounder and native European plaice (Pleuronectes 68 platessa) and further documented signatures of introgression between the species. European 69 flounder x European plaice hybrids are commonly found throughout the overlapping native 70 range of both species but has previously not been documented in Iceland.
Reduction of energy cost of magnetization switching in a biaxial nanoparticle by use of internal dynamics
(American Physical Society (APS), 2023-06-29) Badarneh, Mohammad H. A.; Kwiatkowski, Grzegorz; Bessarab, Pavel; Raunvísindastofnun (HÍ); Science Institute (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
A solution to energy-efficient magnetization switching in a nanoparticle with biaxial anisotropy is presented. Optimal control paths minimizing the energy cost of magnetization reversal are calculated numerically as functions of the switching time and materials properties, and used to derive energy-efficient switching pulses of external magnetic field. Hard-axis anisotropy reduces the minimum energy cost of magnetization switching due to the internal torque in the desired switching direction. Analytical estimates quantifying this effect are obtained based on the perturbation theory. The optimal switching time providing a tradeoff between fast switching and energy efficiency is obtained. The energy cost of switching and the energy barrier between the stable states can be controlled independently in a biaxial nanomagnet. This provides a solution to the dilemma between energy-efficient writability and good thermal stability of magnetic memory elements.
AsymPol-TEKs as efficient polarizing agents for MAS-DNP in glass matrices of non-aqueous solvents
(Royal Society of Chemistry (RSC), 2024) Harrabi, Rania; Halbritter, Thomas; Alarab, Shadi; Chatterjee, Satyaki; Wolska-Pietkiewicz, Malgorzata; Damodaran, Krishna K.; van Tol, Johan; Lee, Daniel; Paul, Subhradip; Hediger, Sabine; Sigurdsson, Snorri Th.; Mentink-Vigier, Frederic; De Paëpe, Gaël; Raunvísindadeild (HÍ); Faculty of Physical Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Two polarizing agents from the AsymPol family, AsymPol-TEK and cAsymPol-TEK (methyl-free version) are introduced for MAS-DNP applications in non-aqueous solvents. The performance of these new biradicals is rationalized in detail using a combination of Electron Paramagnetic Resonance spectroscopy, Density Functional Theory, Molecular Dynamics and quantitative MAS-DNP spin dynamics simulations. By slightly modifying the experimental protocol to keep the sample temperature low at insertion, we are able to obtain reproducable DNP-NMR data with 1,1,2,2-tetrachloroethane (TCE) at 100 K, which facilitates optimization and comparison of different polarizing agents. At intermediate magnetic fields, AsymPol-TEK and cAsymPol-TEK provide 1.5 to 3-fold improvement in sensitivity compared to TEKPol, one of the most widely used polarizing agents for organic solvents, with significantly shorter DNP build-up times of ~ 1 s and ~ 2 s at 9.4 and 14.1 T respectively. In the course of the work, we also isolated and characterized two diastereoisomers that can form during the synthesis of AsymPol-TEK; their difference in performance is described and discussed. Finally, the advantages of the AsymPol-TEKs are demonstrated by recording 2D 13C-13C correlation experiments at natural 13C-abundance of proton-dense microcrystals and by polarizing the surface of ZnO nanocrystals (NCs) coated with diphenyl phosphate ligands. For those experiments, cAsymPol-TEK yielded a three-fold increase in sensitivity compared to TEKPol, corresponding to a nine-fold time saving.
Stirring Up Skyr: From Live Cultures to Cultural Heritage
(University of Illinois Press, 2022) Pétursson, Jón Þór; Hafstein, Valdimar Tr.; Félagsfræði-, mannfræði- og þjóðfræðideild (HÍ); Faculty of Sociology, Anthropology and Folkloristics (UI); Félagsvísindasvið (HÍ); School of Social Sciences (UI)
In recent years, the Icelandic dairy product skyr has been transformed from an everyday staple to a national food heritage. Skyr is high in protein and low in fat, and its nutritional value accounts for its international success. However, the domestic and international marketing of skyr glide effortlessly from medieval literature to modern healthy living in promoting skyr as a unique, wholesome, and authentic product: heritage food and Iceland's “secret to healthy living.” In this article, we explore how skyr has been recontextualized as heritage through the cultural staging of skyr-making and through branding efforts. It was not until skyr had become a standardized export commodity that people began to fear that action was needed to protect the traditional way of skyr-making. Picking up on the trend of “heritagization,” pioneered by Slow Food (which added skyr to its “Ark of Taste”) and by small farmers catering to tourists, industrial skyr producers have come around to narrating the cultural history of skyr, employing heritage branding to carve out a unique place within the global dairy-scape. We untangle the messy relationships between the local and the global in such heritage efforts by examining how global trends and markets influence people at local levels, impacting the way they think about and act on their own cultural forms, and how the local level, in turn, impacts global flows under the sign of heritage.
Fracturing and tectonic stress drive ultrarapid magma flow into dikes
(American Association for the Advancement of Science (AAAS), 2024-03-15) Sigmundsson, Freysteinn; Parks, Michelle; Geirsson, Halldór; Hooper, Andrew; Drouin, Vincent; Vogfjörd, Kristín S.; Ófeigsson, Benedikt G.; Greiner, Sonja H. M.; Yang, Yilin; Lanzi, Chiara; De Pascale, Gregory P.; Jónsdóttir, Kristín; Hreinsdóttir, Sigrún; Tolpekin, Valentyn; Friðriksdóttir, Hildur María; Einarsson, Páll; Barsotti, Sara; Jarðvísindastofnun (HÍ); Institute of Earth Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Many examples of exposed giant dike swarms can be found where lateral magma flow exceeded hundreds of kilometers. We show that massive magma flow into dikes can be established with only modest overpressure in a magma body, if a large enough pathway opens at its boundary, and gradual build-up of high tensile stress has occurred along the dike pathway prior to onset of diking. This explains rapid initial magma flow rates, modeled up to about 7400 m3/s into a dike approximately 15-km-long, propagating under the town of Grindavík, SW-Iceland, in November 2023. Such high flow rates provide insight into the formation of major dikes and imply a serious hazard potential for high flow-rate intrusions that propagate to the surface and transition into eruptions.
The 1975 Icelandic ‘Women’s day off’ in Nordic print media
(Informa, 2024-07-24) Kurvinen, Heidi; Pálmadóttir, Valgerður; Sagnfræði- og heimspekideild (HÍ); Faculty of History and Philosophy (UI); Hugvísindasvið (HÍ); School of Humanities (UI)
In October 1975, the Icelandic women’s movement organized a ‘Women’s Day Off’ (WDO), a one-day strike designed to reveal the societal importance of women’s work. In this article, we explore media coverage of the WDO in the Nordic countries. Through an analytical lens that focuses on media framing and journalistic practices, we analyse differences in the coverage’s scope and content. We also contextualize the coverage against the background of sociopolitical factors that may have affected the cultural filtering of the news, as well as journalistic practices and resources in each country. In doing so, we demonstrate that the coverage relied on each newsroom’s estimation of the event’s newsworthiness for local readers. That news value was influenced by the country in question’s cultural proximity to Iceland, the state of local feminist organizing and public discussions regarding gender equality, and other news topics in circulation at the time. Our analysis is based on a reading of media texts related to the WDO that we gathered using digital interfaces of the national libraries of Norway, Denmark, Sweden and Finland, complemented by a manual search in cases where such digitization was lacking.
Nordic Feminism Reconsidered: Activism, Scholarly Endeavours and Women’s Research Networks at the Nordic Summer University 1971–1990
(Informa, 2021-09-28) Palmadottir, Valgerdur; Sjöstedt, Johanna; Sagnfræði- og heimspekideild (HÍ); Faculty of History and Philosophy (UI); Hugvísindasvið (HÍ); School of Humanities (UI)
In our paper presentation, we explore the Nordic Summer University (NSU), an independent and migratory scholarly organisation, as a platform for interaction and cooperation for the new women’s movements and an arena for the development of women’s research in the Nordic region. In several accounts, NSU is described as a key context for the development of Nordic women’s and feminist research and frequently appears in memoirs by pioneers in the field, but it has never been the direct object of scholarly focus. In recent years, there has been a scholarly debate about the historical narratives concerning the history of academic feminism in the Nordic region, where both the connection to the new women’s movements in the 1970s and the notion of the ‘Nordic’ have been contested. This article intervenes in these discussions by exploring the ‘women’s circles’ within NSU as they appear in various sources such as historiographical accounts, reports memoirs and archives and thereby, thereby defending a hands-on archival approach. We argue that focusing on an alternative international institution for knowledge production such as NSU offers valuable insights into how feminism as a social movement and a scholarly project - politics and academic endeavours - have been negotiated.
Human Small Heat Shock Protein B8 Inhibits Protein Aggregation without Affecting the Native Folding Process
(American Chemical Society (ACS), 2023-07-06) Choudhary, Dhawal; Mediani, Laura; Avellaneda, Mario J.; Bjarnason, Sveinn; Alberti, Simon; Boczek, Edgar E.; Heidarsson, Pétur O.; Mossa, Alessandro; Carra, Serena; Tans, Sander J.; Cecconi, Ciro; Raunvísindastofnun (HÍ); Science Institute (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Small Heat Shock Proteins (sHSPs) are key components of our Protein Quality Control system and are thought to act as reservoirs that neutralize irreversible protein aggregation. Yet, sHSPs can also act as sequestrases, promoting protein sequestration into aggregates, thus challenging our understanding of their exact mechanisms of action. Here, we employ optical tweezers to explore the mechanisms of action of the human small heat shock protein HSPB8 and its pathogenic mutant K141E, which is associated with neuromuscular disease. Through single-molecule manipulation experiments, we studied how HSPB8 and its K141E mutant affect the refolding and aggregation processes of the maltose binding protein. Our data show that HSPB8 selectively suppresses protein aggregation without affecting the native folding process. This anti-aggregation mechanism is distinct from previous models that rely on the stabilization of unfolded polypeptide chains or partially folded structures, as has been reported for other chaperones. Rather, it appears that HSPB8 selectively recognizes and binds to aggregated species formed at the early stages of aggregation, preventing them from growing into larger aggregated structures. Consistently, the K141E mutation specifically targets the affinity for aggregated structures without impacting native folding, and hence impairs its anti-aggregation activity.
Prediction of stable nanoscale skyrmions in monolayer Fe5GeTe2
(American Physical Society (APS), 2024-06-10) Li, Dongzhe; Haldar, Soumyajyoti; Kollwitz, Leo; Schrautzer, Hendrik; Goerzen, Moritz A.; Heinze, Stefan; Raunvísindastofnun (HÍ); Science Institute (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Using first-principles calculations and atomistic spin simulations, we predict stable isolated skyrmions with a diameter below 10 nm in a monolayer of the two-dimensional van der Waals ferromagnet Fe5⁢GeTe2, a material of significant experimental interest. A very large Dzyaloshinskii-Moriya interaction (DMI) is observed due to the intrinsic broken inversion symmetry and strong spin-orbit coupling for monolayer Fe5⁢GeTe2. We show that the nearest-neighbor approximation, often used in the literature, fails to describe the DMI. The strong DMI together with moderate in-plane magnetocrystalline anisotropy energy allows to stabilize nanoscale skyrmions in out-of-plane magnetic fields above ≈2 T. The energy barriers of skyrmions in monolayer Fe5⁢GeTe2 are comparable to those of state-of-the-art transition-metal ultrathin films. We further predict that these nanoscale skyrmions can be stable for hours at temperatures up to 20 K.
Variation in personality shaped by evolutionary history, genotype and developmental plasticity in response to feeding modalities in the Arctic charr
(The Royal Society, 2023-12-13) Dellinger, Marion; Dellinger, Marion; Steele, Sarah Elizabeth; Steele, Sarah; Sprockel, Evert; Sprockel, Evert; Philip, Joris; Joris, Philip; Pálsson, Arnar; Pálsson, Arnar; Benhaïm, David; Benhaïm, David; Líf- og umhverfisvísindadeild (HÍ); Life- and Environmental Sciences; Faculty of Life and Environmental Sciences (UI); School of Engineering and Natural Sciences; Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Animal personality has been shown to be influenced by both genetic and environmental factors and shaped by natural selection. Currently, little is known about mechanisms influencing the development of personality traits. This study examines the extent to which personality development is genetically influenced and/or environmentally responsive (plastic). We also investigated the role of evolutionary history, assessing whether personality traits could be canalized along a genetic and ecological divergence gradient. We tested the plastic potential of boldness in juveniles of five Icelandic Arctic charr morphs (Salvelinus alpinus), including two pairs of sympatric morphs, displaying various degrees of genetic and ecological divergence from the ancestral anadromous charr, split between treatments mimicking benthic versus pelagic feeding modalities. We show that differences in mean boldness are mostly affected by genetics. While the benthic treatment led to bolder individuals overall, the environmental effect was rather weak, suggesting that boldness lies under strong genetic influence with reduced plastic potential. Finally, we found hints of differences by morphs in boldness canalization through reduced variance and plasticity, and higher consistency in boldness within morphs. These findings provide new insights on how behavioural development may impact adaptive diversification.
DNA binding redistributes activation domain ensemble and accessibility in pioneer factor Sox2
(Springer, 2024-02-16) Bjarnason, Sveinn; McIvor, Jordan A.P.; Prestel, Andreas; Demény, Kinga S.; Bullerjahn, Jakob T.; Kragelund, Birthe B.; Mercadante, Davide; Heiðarsson, Pétur O.; Raunvísindadeild (HÍ); Faculty of Physical Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
More than 1600 human transcription factors orchestrate the transcriptional machinery to control gene expression and cell fate. Their function is conveyed through intrinsically disordered regions (IDRs) containing activation or repression domains but lacking quantitative structural ensemble models prevents their mechanistic decoding. Here we integrate single-molecule FRET and NMR spectroscopy with molecular simulations showing that DNA binding can lead to complex changes in the IDR ensemble and accessibility. The C-terminal IDR of pioneer factor Sox2 is highly disordered but its conformational dynamics are guided by weak and dynamic charge interactions with the folded DNA binding domain. Both DNA and nucleosome binding induce major rearrangements in the IDR ensemble without affecting DNA binding affinity. Remarkably, interdomain interactions are redistributed in complex with DNA leading to variable exposure of two activation domains critical for transcription. Charged intramolecular interactions allowing for dynamic redistributions may be common in transcription factors and necessary for sensitive tuning of structural ensembles.
Wilderness: a resource or a sanctuary? Views of tourism service providers
(2023-05-27) Tverijonaite, Edita; Sæþórsdóttir, Anna; Ólafsdóttir, Rannveig; Hall, C. Michael; Líf- og umhverfisvísindadeild (HÍ); Faculty of Life and Environmental Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
The growing popularity of nature-based tourism means that the tourism industry is increasingly utilizing wilderness areas to provide visitor experiences. However, tourism activities negatively impact wilderness quality. Tourism service providers play an important role in shaping these impacts. Therefore, this study investigates their preferences regarding wilderness use and development. It focuses on the Icelandic Central Highlands, which contain some of Europe’s largest wildernesses and are an important venue for tourism. The relationship between participants’ preferences and environmental attitudes is also investigated, providing insights into the reasoning behind these preferences. For this study an online questionnaire was distributed among day tour providers and travel agencies operating in Iceland. The results revealed that the attitudes of over 87% of the participants were pro-environmental. Accordingly, most tourism service providers preferred basic tourism infrastructure in the Central Highlands, and they did not support further energy or road developments. However, their attitudes toward the Central Highlands National Park proposal were divergent despite the positive relationship with environmental attitudes. Concerns about regulations and access restrictions to the area played an important role in shaping the attitudes toward the national park proposal, demonstrating the importance of considering tourism stakeholders’ interests for ensuring their support for wilderness conservation.
Therapie- und Compliance-Faktoren aus Sicht der am Behandlungsprozess beteiligten Experten am Beispiel Rückenschmerz
(Pabst, 2018) Staub, Maya; Gursch, Ann-Marie; Puschmann, Anne-Katrin; de Witt Huberts, Jessie; Müller, Juliane; Wippert, Pia-Maria; Vísinda- og nýsköpunarsvið (HÍ); Science and Innovation (UI); Miðlæg stjórnsýsla (HÍ); Central administration (UI)
Ziel: Inwiefern physio- oder trainingstherapeutische Programme bei chronisch unspezifischen Ruckenschmerzen (CURS) nachhaltig wirksam sind, hangt masgeblich von der Compliance der Teilnehmer ab. Ziel der Studie ist es daher, aus Sicht der Behandler zu untersuchen, welche Faktoren bei einem Trainingsprogramm eine hohe Compliance begunstigen und welche einen Trainingsabbruch eher begunstigen. Methodik: Es wurden neun leitfadengestutzte qualitative Interviews mit ArztInnen sowie Sport- und PhysiotherapeutInnen durchgefuhrt, die N=154 Teilnehmer bei einem uni- und multimodalen Trainingsprogramm (klinik- und heimbasiert) begleiteten (dreiarmige Interventionsstudie). Diese behandelnden ExpertInnen (BE) sollten dabei beurteilen, welche Faktoren die Compliance der TeilnehmerInnen positiv oder negativ beeinflusst haben. Die Interviews wurden inhaltsanalytisch entlang von vier Kernkategorien ausgewertet. Neben zentralen Aspekten bzgl. Ablauf und Organisation wurden die BE um eine Einschatzung hinsichtlich der (1) Patienten-Zufriedenheit, (2) Compliance fordernden bzw. hemmender Faktoren, (3) subjektiven Wirksamkeit und (4) dem Verbesserungspotential erbeten. Ergebnisse: Den vier Kernkategorien liesen sich sieben Subkategorien mit 45 Kodierungen zuordnen. Die Befragten nannten folgende Faktoren als ausschlaggebend fur die Compliance: sorgfaltige Aufklarung von Teilnehmern1 und Behandlern, unterstutzende therapeutische Atmosphare und eine angemessene Lange und Dauer der Ubungen sowie Untersuchungen. Fur eine Erhohung der Compliance schlugen sie Masnahmen zur Verbesserung der Motivation der Behandler sowie fur die heimbasierte Trainingsphase eine engmaschigere Unterstutzung der Programmteilnehmer vor. Schlussfolgerung: Wenngleich die BE das Programm grundsatzlich positiv einschatzten, berichteten sie von einer besseren Compliance der TeilnehmerInnen wahrend der aufwandigeren klinikbasierten Phase im Vergleich zur heimbasierten Intervention. Sollten Interventionen folglich zuhause durchgefuhrt werden, so gilt es Masnahmen zu ergreifen, um die Compliance aufrechtzuhalten, wie bspw. Regelmasige Termine zur Uberprufung der Ubungsausfuhrung. Die Ergebnisse liefern wichtige Anhaltspunkte fur den Einsatz eines solchen Programms im Rahmen einer heimbasierten Rehabilitationsnachsorge in landlichen Regionen.
Adaptive cellular evolution or cellular system drift in hares
(Wiley, 2023-05-31) Palsson, Arnar; Steele, Sarah Elizabeth; Steele, Sarah Elizabeth; Líf- og umhverfisvísindastofnun (HÍ); Institute of Life and Environmental Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Adaptations occur at many levels, for example, from DNA sequence of regulatory elements and cellular homeostatic systems to organismal physiology and behaviour (Mayr, 1997). Established adaptations are maintained by purifying and stabilizing selection. Students of animal diversity tend to focus on higher order traits, anatomy, physiology, organismal function and interactions. The core cellular and metabolic systems of metazoans evolved early in their history and are assumed to be rather similar between groups. The housekeeping functions and core metabolic functions of cells are generally considered relatively static, especially among closely related species. The extent to which evolution shapes core cellular metabolism and physiology in animals is largely unexplored. Ecological opportunities or strong positive selection can alter basal metabolic rate, activity levels and life-history traits (e.g., life span, age of maturity, offspring number) and potentially lead to divergence in core cellular and metabolic trait systems (Norin & Metcalfe, 2019; Speakman, 2005). Furthermore, systems under stabilizing selection can also change. Developmental systems of related species may produce the same phenotype or structure, but experience drift that can alter connections and even lead to turnover of cogs in the system (True & Haag, 2001). Are the cellular functions of animals highly constrained, subject to cellular system drift or affected by positive selection? This was tackled by a new study by Kateryna Gaertner and colleagues in a From the Cover manuscript in this issue of Molecular Ecology (Gaertner et al., 2022), using fibroblasts from the closely related but ecologically distinct brown and mountain hares.
Diversity in the internal functional feeding elements of sympatric morphs of Arctic charr (Salvelinus alpinus)
(Public Library of Science (PLoS), 2024-05-21) Jónsdóttir, Guðbjörg Ósk; Jónsdóttir, Guðbjörg Ósk; von Elm, Laura-Marie; von Elm, Laura-Marie; Ingimarsson, Finnur; Tersigni, Samuel; Tersigni, Samuel; Snorrason, Sigurður Sveinn; Snorrason, Sigurður Sveinn; Pálsson, Arnar; Pálsson, Arnar; Steele, Sarah Elizabeth; Steele, Sarah Elizabeth; Líf- og umhverfisvísindastofnun (HÍ); Insitute of Life and Environmental Science; Institute of Life and Environmental Sciences (UI); School of Science and Engineering; Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
The diversity of functional feeding anatomy is particularly impressive in fishes and correlates with various interspecific ecological specializations. Intraspecific polymorphism can manifest in divergent feeding morphology and ecology, often along a benthic–pelagic axis. Arctic charr (Salvelinus alpinus) is a freshwater salmonid known for morphological variation and sympatric polymorphism and in Lake Þingvallavatn, Iceland, four morphs of charr coexist that differ in preferred prey, behaviour, habitat use, and external feeding morphology. We studied variation in six upper and lower jaw bones in adults of these four morphs using geometric morphometrics and univariate statistics. We tested for allometric differences in bone size and shape among morphs, morph effects on bone size and shape, and divergence along the benthic-pelagic axis. We also examined the degree of integration between bone pairs. We found differences in bone size between pelagic and benthic morphs for two bones (dentary and premaxilla). There was clear bone shape divergence along a benthic–pelagic axis in four bones (dentary, articular-angular, premaxilla and maxilla), as well as allometric shape differences between morphs in the dentary. Notably for the dentary, morph explained more shape variation than bone size. Comparatively, benthic morphs possess a compact and taller dentary, with shorter dentary palate, consistent with visible (but less prominent) differences in external morphology. As these morphs emerged in the last 10,000 years, these results indicate rapid functional evolution of specific feeding structures in arctic charr. This sets the stage for studies of the genetics and development of rapid and parallel craniofacial evolution.
Genetic structure and relatedness of brown trout (Salmo trutta) populations in the drainage basin of the Ölfusá river, South-Western Iceland
(PeerJ, 2023-09-05) Lagunas, Marcos; Palsson, Arnar; Jónsson, Benóný; Jóhannsson, Magnús; Jónsson, Zophonías Oddur; Snorrason, Sigurður S.; Líf- og umhverfisvísindastofnun (HÍ); Institute of Life and Environmental Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ); School of Engineering and Natural Sciences (UI)
Background Lake Þingvallavatn in Iceland, a part of the river Ölfusá drainage basin, was presumably populated by brown trout soon after it formed at the end of the last Ice Age. The genetic relatedness of the brown trout in Þingvallavatn to other populations in the Ölfusá drainage basin is unknown. After the building of a dam at the outlet of the lake in 1959 brown trout catches declined, though numbers have now increased. The aim of this study was to assess effects of geographic isolation and potential downstream gene flow on the genetic structure and diversity in brown trout sampled in several locations in the western side of the watershed of River Ölfusá. We hypothesized that brown trout in Lake Þingvallavatn constituted several local spawning populations connected by occasional gene flow before the damming of the lake. We also estimated the effective population size (NE) of some of these populations and tested for signs of a recent population bottleneck in Lake Þingvallavatn. Methods We sampled brown trout inhabiting four lakes and 12 rivers within and near the watershed of River Ölfusá by means of electro- and net- fishing. After stringent data filtering, 2,597 polymorphic loci obtained from ddRADseq data from 317 individuals were ascertained as putative neutral markers. Results Overall, the genetic relatedness of brown trout in the Ölfusá watershed reflected the connectivity and topography of the waterways. Ancestry proportion analyses and a phylogenetic tree revealed seven distinct clusters, some of which corresponded to small populations with reduced genetic diversity. There was no evidence of downstream gene flow from Lake Þingvallavatn, although gene flow was observed from much smaller mountain populations. Most locations showed low NE values (i.e., ~14.6 on average) while the putative anadromous trout from River Sog and the spawning population from River Öxará, that flows into Lake Þingvallavatn, showed notably higher NE values (i.e., 71.2 and 56.5, respectively). No signals of recent population bottlenecks were detected in the brown trout of Lake Þingvallavatn. Discussion This is the first time that the genetic structure and diversity of brown trout in the watershed of River Ölfusá have been assessed. Our results point towards the presence of a metapopulation in the watershed of Lake Þingvallavatn, which has been influenced by restoration efforts and is now dominated by a genetic component originated in River Öxará. Many of the locations studied represent different populations. Those that are isolated in headwater streams and lakes are genetically distinct presenting low genetic diversity, yet they can be important in increasing the genetic variation in downstream populations. These populations should be considered for conservation and direct management.

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