Opin visindi
Not a member yet
2982 research outputs found
Sort by
Lung innate immunity responses upon challenge
No full textInnate immunity of the lung epithelium provides efficient defenses against pathogens or
other stress factors by secretion of antimicrobial peptides, presence of cellular junction
proteins and autophagy. Upon activation through epithelial cell receptors the system
triggers a defense response. Activation of epithelial immunity can lead to elimination of
bacteria, enhanced epithelial integrity and lysosomal degradation. Therefore, modulation of immune signalling for epithelial immunity by specific inducers can serve as a treatment strategy to fight infections. The use of innate immunity modulators is of interest for management of ventilator induced lung injury (VILI), that can lead to acute respiratory
distress syndrome (ARDS) in patients.
The aim of this work was to investigate the effect of the aroylated phenylenediamine (APD) inducers HO53 and HO56 and mechanical stress on the innate immunity in the lung epithelium.
The novel compounds HO53 and HO56 induced expression of antimicrobial effectors in
bronchial epithelium and reduced bacterial entry. Both APD inducers exhibited a synergistic effect with vitamin D on CAMP gene expression and HO53 activated the
STAT3 transcription factor. The HO53 compound enhanced epithelial barrier integrity and
promoted induction of autophagy in differentiated cells. Treatment with HO53 had broad
effect on gene expression, including expression of histone modifying enzymes and
stimulated AMPK pathway together with TFEB activation.
Mechanical stress generated by the cyclical pressure air-liquid device (CPAD) affected cell morphology and expression of markers for VILI and ARDS development together with pro-inflammatory genes. A preliminary study indicates that HO53 compound exacerbates pro-inflammatory response induced by mechanical stress.Náttúrulegt ónæmi lungnaþekju myndar virkt varnarkerfi með seytingu örverudrepandi
peptíða, myndun þéttitengja og sjálfsáti. Varnarkerfið virkjast með örvun viðtaka í
þekjunni og getur leitt til þess að bakteríum er eytt, þéttni þekjunnar aukist og að virkni
leysikorna sé örvuð. Með því að hafa áhrif á boðleiðir fyrir náttúrulegt ónæmi með
sérhæfðum efnum má örva kerfið til að verjast sýkingum. Notkun á efnum sem örva
boðleiðir þekjuvarna eru áhugaverður möguleiki tengt sýkingum en einnig í
öndunarvélatengdum lungnaskaða (ÖTL) til að hindra brátt andnauðarheilkenni (BAH)
sjúklinga í öndunarvél.
Markmið verkefnisins var að rannsaka áhrif nýrra örvunarefna, aroylated phenylenediamin (APD) efna á náttúrulegt ónæmi og skoða áhrif þrýstings og slitálags á þekjuvarnakerfið.
Ný APD örvunarefni HO53 og HO56 juku tjáningu örverudrepandi efna í lungnaþekju og
drógu úr innrás baktería í þekjufrumur. Bæði APD efnin sýndu samverkan með vítamín D
fyrir örvun á CAMP cathelicidin geninu og HO53 virkjaði STAT3 umritunarþáttinn í þeirri
örvun. Meðhöndlun á skautuðum þekjufrumum með HO53 styrkti þekjuna og jók sjálfsát.
HO53 hafði víðtæk áhrif á genatjáningu í frumunum sérstaklega tjáningu umbreytiensíma fyrir históna, en örvaði jafnframt AMPK boðleiðina og virkjaði TFEB umritunarþáttinn.
Þrýstingsálag í sérhönnuðu tæki CPAD (e. cyclical pressure air-liquid device) hafði áhrif á útlit þekjunnar og tjáningu lífmerkja (e. biomarkers) fyrir ÖTL, BAH og bólgumiðla.
Fyrsta athugun sýnir að HO53 efnið eykur á bólguviðbragð sem örvað hafði verið með
þrýstingsálagi.The project was supported by the Icelandic Center for Research (RANNÍS) and University
of Iceland research fund. Akthelia Pharmaceuticals holds a patent on APD compounds,
Patent No. US 9,957,226 B2 and sponsored synthesis of the compounds
Operationalization of Interorganizational Fairness in Food Systems: From a Social Construct to Quantitative Indicators
Get PDF© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
CC BYFairness issues within food systems are of increasing concern for policy makers and other stakeholders. Given the topicality and policy relevance of fairness within food systems, there is value in exploring the subject further. Simulation modelling has been successfully used to develop and test policy interventions. However, the subjectivity and intangibleness of fairness perceptions make them difficult to operationalize in a quantitative model. The objective of this study is to facilitate research on fairness in food systems using simulation modelling by defining the social construct of fairness in model operational terms. The operationalization is conducted in two steps. First, the construct of fairness is conceptually defined in terms of its dimensions, antecedents, and consequences using the literature on interorganizational fairness. Then, by focusing specifically on fairness issues within food systems, the conceptual definition is used as a basis for the identification of proxy indicators of fairness. Seven groups of factors related to fairness perceptions were identified during the conceptualization phase: financial outcomes, operational outcomes, power, environmental stability, information sharing, relationship quality, and controls. From these factor groups, five indicators of fairness that are operational in a quantitative model were identified: profit margin as an indicator of distributive fairness and four indicators of procedural fairness related to market power and bargaining power.This research was part of the VALUMICS project “Understanding Food Value Chain and Network Dynamics” funded by the European Union’s Horizon 2020 research and innovation program, https://valumics.eu/.Peer reviewe
Co-production processes underpinning the ecosystem services of glaciers and adaptive management in the era of climate change
Get PDFPre-print / Óritrýnd útgáfa greinar
© 2021 Elsevier B.V. All rights reserved.Glaciers have been an increasingly studied topic in the ecosystem services (ES) literature, with 6 multiple scientific studies affirming a critical and diverse contribution to human well-being. 7 However, the literature to date on glacier ES has lacked a systematic analysis of their type and 8 the various stages in the formation of glacier ES, including the linkages between biophysical 9 structures and ecological processes to human values, benefits and well-being. This paper begins 10 to fill this gap by (1) detailing the first Common International Classification for Ecosystem 11 Services classification of ecosystem services specific to glaciers; and (2) constructing an ES 12 cascade model specific to the ES of glaciers, integrating four main stages of co-production: 13 value attribution, mobilisation of ES potential, value appropriation, and commercialisation. In 14 both stages, examples from the academic and grey literature are highlighted. Based on a 15 systematic literature review, a total of 15 ES are identified, categorised as follows: provisioning
16 (2), regulation and maintenance (6), and cultural (7). Apart from abiotic regulation and
17 maintenance ES, it is evident that human interventions are necessary in order to mobilise, 18 appropriate and commercialise several glacier ES, including freshwater for drinking, 19 hydropower generation, recreation and education. Rapidly intensifying climate change has led 20 to intense focus on the initial co-production process of value attribution and identification of 21 dynamic ecosystem services potential, with a view to maximising commercial benefits in the 22 coming decades where this is possible, especially linked to hydropower generation from glacial 23 rivers. However, this study also finds that adaptive ecosystem management is a necessary pre24 requisite of resilience but may be insufficient in this context to address potential ecosystem 25 disservices and potentially catastrophic impacts to human well-being, such as from dangerous 26 glacier outburst floods.This paper has been funded by NordForsk (grant number 76654) via their financial support to
743 the Nordic Centre of Excellence ARCPATH (Arctic Climate Predictions – Pathways to
744 Resilient, Sustainable Communities)
Fisheries Management under Individual Transferable Quota Outcomes for Ecology and Equity
Get PDFThesis for double degree Stockholm University, University of IcelandThe management of marine resources pose a difficult commons problem as monitoring behavior is difficult and benefit flows from the resources are uncertain. Implementing individual transferable quota (ITQ) is a management regime in which quasi-property rights are assigned for an often mobile and uncertain environmental resource, fish or marine invertebrates. This thesis addresses sustainability impacts of ITQ’s as a fisheries management tool. The findings demonstrate that fisheries management regimes in which fisheries opportunities are allocated as quota and / or are allocated individually experience reduced overfishing compared to controls that do not have these attributes (Paper I), however the analysis found less support for transferability and no support for longer duration being associated to any change in the probability of overfishing. In addition, a longitudinal study showed that with an adaptive design ecological and economic goals could be balanced in an important mixed fishery in Iceland (Paper II), and based on such findings suggested that several policy changes could be implemented to modify the ecological risk of catch-quota balancing allowances. Additional longitudinal analyses allowed to conclude that rapid consolidation in an important small-boat fishing sector in Iceland, which may have had negative implications for local fishing communities (Paper III), and that on average since the introduction of ITQ’s total amount of quota traded stayed below around 60% for the main commercial species in the Icelandic ITQ system. Moreover, the results of Paper IV also show that in case of a credible announcement of quota revocation in the future there would be scope for policy reform. Finally, research is beginning to emerge that shows that marine species are unequally affected by climate change. In a final chapter the analyses show that under different scenarios of global change a re-shaping of the Icelandic foodweb is likely (Paper V). The re-shaping of the foodweb will be to the benefit of some resource users and to the loss of others. In general, the findings from all the analyses together demonstrate that there could be benefits to individual quota implementation for fisheries sustainability and that some of the hypothesized trade-offs could potentially be balanced, the thesis highlights ways forward in investigating the common pool problems in fisheries management.Adaptation to a New Economic Reality (AdaptEconII) Marie Curie Innovative Training Network, funded by the European Commission (H2020-MSCA ITN-2015, Grant No. 675153). University of Iceland Eimpskip Fund under Project 1538- 153310
Sustainable energy development: History of the concept and emerging themes
Get PDFSustainable energy development is a complex multi-dimensional concept that can vary in meaning based on the context it is applied in and the perspective of the user. The role of energy in achieving sustainable development was recognized when the concept was first put forward in 1987. However, what that role consisted of was not made clear. Since then, the concept of sustainable energy development has developed to become a prominent policy objective on the international agenda, as evidenced by the introduction of the UN's Sustainable Development Goal 7 on energy. This paper presents an overview of the history of the concept as well as its emerging themes. Through a citation analysis, the most cited open-access publications relevant to the concept were identified. A thematic analysis of these most cited publications led to the identification of four interrelated themes of sustainable energy development; access to affordable modern energy services, sustainable energy supply, sustainable energy consumption, and energy security. The overarching goal of sustainable energy development was defined as furthering sustainability. Equitable access to affordable and reliable modern energy services is integral to sustainable development. A transformation of the current energy system is necessary to reduce its harmful impacts, both on the supply and demand side. This transformation is not possible unless it is economically viable through, for instance, cost-competitive technologies and changes in energy pricing to reflect the external costs of energy.This research was financially supported by Rannis – The Icelandic Centre for Research [grant number: 163464–051], the National Power Company of Iceland, the Icelandic Road and Coastal Administration, the Eimskip University Fund, and the Icelandic national federation of Graduate Women International
Global Phosphorus supply chain dynamics: Sustainability implications for the 21st century
Get PDFPhosphorus is an essential yet irreplaceable macronutrient for agriculture and thus plays a key role in global food security. Most of the phosphate fertilizers are produced from phosphate rock, a finite mineral resource that is mined and processed at great environmental and social costs. Nonetheless, the present-day phosphorus supply chain transforms this valuable resource also into a major pollutant of water bodies. The research that is presented in this thesis investigated the sustainability challenges of the currently linear phosphorus supply chain and discussed their implications. The main methods used were literature and case study review, semi-structured interviews with stakeholders from the phosphorus sector, stakeholder analysis, systems analysis and system dynamics modelling. Five key messages emerged from this project.
First, it is necessary to close the loop throughout the phosphorus supply chain instead of focusing only on end-of-pipeline solutions. Second, in terms of monitoring data, the global phosphorus supply chain is a black box. This poses serious challenges to designing robust policies in food security. Third, industrializing world regions where most of the population growth is expected to occur in the coming decades are increasingly vulnerable to phosphorus scarcity. Fourth, in a business-as-usual scenario, the global supply chain of phosphorus will produce significant amounts of toxic by- products, will have an increasingly negative impact on the climate and will deteriorate the quality of water bodies. Finally, implementing low-input sustainable farming systems, such as agroecology, was shown to have the potentially largest impact in reducing P requirement and in decreasing the negative socio-environmental impacts of the global P supply chain.Fosfór er nauðsynlegt en um leið óútskiptanlegt næringarefni fyrir landbúnað og gegnir
því lykilhlutverki hvað alþjóðlegt fæðuöryggi varðar. Flestir fosfatáburðir eru
framleddir úr fosfatríku bergi, sem er endanlegt steinefni og er námugrafið og frekar
unnið með miklum umhverfis- og félagslegum kostnaði. Engu að síður umbreytir
núverandi fosfóraðfangskeðja þessari dýrmætu auðlind í aðalmengunarefni vatnsbóla.
Rannsóknirnar sem kynntar eru í þessari ritgerð lúta að sjálfbærniáskorunum núverandi
línulegrar fósfórkeðju og fjalla um afleiðingar þeirra. Helstu aðferðir sem notaðar voru
í þessari rannsókn voru greining fræðirita, endurskoðun á tilviksrannsóknum, skipulögð
viðtöl við hagaðila úr fosfórgeiranum, greining hagaðila, kerfisgreining og kvik
kerfislíkanagerð. Fjórar lykilniðurstöður komu fram í þessu verkefni.
Í fyrsta lagi er nauðsynlegt að loka fosfórsbirgiskeðjulykkjunni í stað þess að einbeita
sér einungis að lausnum sem varða lokun keðjunnar. Í öðru lagi, hvað varðar eftirlit, er
alþjóðleg fosfór aðfangskeðja svartur kassi. Þetta hefur í för með sér alvarlegar
áskoranir í að setja fram öfluga stefnu í matvælaöryggi. Í þriðja lagi eru
iðnaðarþróunarsvæði heimsins, þar sem búast má við að mest fólksfjölgun eigi sér stað á
næstu áratugum, sífellt viðkvæmari fyrir forfórskorti. Í fjórða lagi, í venjulegum
viðskiptum (e. business as usual), mun aðfangakeðja fosfórs framleiða mikið magn af
eitruðum aukaafurðum, sem munu hafa sífellt neikvæðari áhrif á loftslagið og rýra gæði
vatnsbóla. Að lokum, innleiðing lág-inntaks, sjálfbærra landbúnaðarkerfa, svo sem
vistlandbúnaðs (e. agroecology) hefur mest áhrif á að minnka fosfórþörf og draga úr
neikvæðum félags- og umhverfisáhrifum fosfóraðfangskeðjunnar.European Commission (H2020- MSCA ITN-2015, Grant No. 675153
Mapping Education for Sustainability in the Nordic Countries
No full textThis report presents some of the main results of research conducted on Education
for Sustainable Development (ESD) in the Nordic countries – one of Iceland’s
presidency projects for the Nordic Council of Ministers initiated in 2019 under the
heading A Common Path (Nordic Council of Ministers, 2018). Iceland’s presidency
focused on the UN Sustainable Development Goals (UNSDGs) with special attention
to young people. This was emphasised by the Prime Minister of Iceland and the
Minister for Nordic Cooperation who introduced the projects.
The Icelandic Presidency will focus on issues concerning young people in the Nordic
region – the generation born around the turn of the century beginning to make its
way in life. We want to listen to young people and support projects that promote
education, culture and health. (Nordic Council of Ministers, 2018, p. 5)
The project presented in this report concerns the implementation of UN Sustainable
Development Goal 4.7 in compulsory education in Denmark, Finland, Iceland,
Norway, and Sweden. The aim was both to receive an overview of how well each of
the Nordic countries had integrated the UNSDGs into their educational policies and
practices. There are seventeen UNSDGs; Goal 4 concerns education specifically. The
sub-goal on which we focused our research was UNSDG 4.7 which states:
By 2030, ensure that all learners acquire the knowledge and skills needed to promote
sustainable development, including, among others, through education for
sustainable development and sustainable lifestyles, human rights, gender equality,
promotion of a culture of peace and non-violence, global citizenship and
appreciation of cultural diversity and of culture’s contribution to sustainable
development.
As one can immediately see, the goal is broad and, therefore, a thorough mapping of
its implementation was outside of the present project’s scope. However, we attempt
to outline a picture of how things stand in the Nordic countries, looking at legislation,
curriculum, teacher education, and local implementation with the aim of identifying
a “Nordic Perspective”. We try to bring out not only how things stand in each
country, but also to shed light on what is common and where things differ. The more
we have worked on this, the more we are painfully aware of how our work does little
more than scratch the surface. But in order to go deeper, one has to begin by
scratching the surface. We hope that what we present here goes a little further than
the bare surface and, more importantly, will help others to continue to dig deeper.Nordic Council of MinistersEdite
Electrochemical production of Al–Mn alloys during the electrodeposition of aluminium in a laboratory cell
Get PDFPublisher's version (útgefin grein)This study reports the direct production of an aluminium–manganese alloy during aluminium electrolysis in fluoride-based melts. Experiments were conducted in a laboratory cell dedicated for current efficiency measurements. The temperature was varied from 965–980 °C at a cathodic current density (CCD) of 0.9 A/cm2 and a cryolite ratio (CR) of 2.2. The manganese content was up to 3.0 wt%. Manganese was added in the form of Mn2O3. Bath samples were collected regularly and analyzed with ICP-MS to observe the decay of manganese during electrolysis. It was possible to produce Al-Mn alloys of up to 21 wt. % Mn. Current efficiency for the electrodeposition of Al–Mn alloy was estimated to be in the range of 93%. Current efficiencies with respect to aluminium were estimated. The solidified surfaces of the metal deposits were mostly flat, but some were deformed.Norges Teknisk-Naturvitenskapelige UniversitetPeer reviewe
Disputed dams: Mapping the divergent stakeholder perspectives, expectations, and concerns over hydropower development in Iceland and SwitzerlandDisputed dams: Mapping the divergent stakeholder perspectives, expectations, and concerns over hydropower development in Iceland and Switzerland
No full textPublisher's version (útgefin grein)The evaluation of the stakeholders’ perception of new hydropower projects is essential for assessing public acceptance, ensuring local involvement, and identifying feasible and desirable changes towards sustainable development. This study uses the concept of causal diagrams (CD) to identify the individual perspectives of stakeholders of two new hydropower projects, one in Switzerland (Val d’Ambra project) and one in Iceland (Hvammvirkjun project). For this purpose, semi-structured interviews with relevant stakeholders were conducted, which were then categorized into 5 interest groups. Using the software Atlas.ti, we identified and sequenced the perceived causality of impact pathways of the two projects. The results are exposed in two series of 10 topical causal networks, and two aggregated diagrams. For each case, CDs expose the complexity of multi-sequenced causalities between elements of a very heterogeneous nature, as expected and reported by stakeholders. This approach enables the identification of inter- and intra-group conflicting perspectives, and perceived uncertainties, concerning both subjectives matters along with much more tangible and predictable aspects. Our method enables the identification of areas where further research or better transfer of information between stakeholders is required. It also exposes how hydropower impacts can differ in time and space, when in one case study, intracommunity tensions and conflicts were identified at the earliest project stage, along with psychological distress of some local residents. Based on the presented CD, we conclude that this method can facilitate communication and problem-solving in complex social-environmental situations amid multiple stakeholder categories, which heterogeneity should not be underestimated.Peer Reviewed (ritrýnd grein
Determination of the Atomic Structure of Metal Nanoclusters from Aberration-Corrected Scanning Transmission Electron Microscope Images
Get PDFDetermining the atomic structure of nanoclusters is a challenging task and a critical
one for understanding their chemical and physical properties. To fully understand the
properties of a nanocluster, it is necessary to know the positions of the atoms in the
nanocluster. Recently, the high-resolution aberration-corrected scanning transmission
electron microscope (AC-STEM) technique has provided valuable information about
such systems. While the AC-STEM experimental equipment is highly developed, the
analysis of the images in terms of the atomic structure of the clusters is still often
qualitative rather than quantitative.
In this work, a general method applicable in studies of irregular atomic structures has
been developed for quantitative analysis of AC-STEM images of nanoclusters. An
objective function formed by a linear combination of a measure of the agreement of a
simulated image with the measured AC-STEM image plus an approximate description
of the atomic interactions is used in a global optimization algorithm to extract the atomic
coordinates. The method is first illustrated by analyzing synthetic images generated
from regular as well as irregular structures of Au55 nanocluster. As the method does not
rely on the alignment of atoms, all the structures can be successfully determined even
when a significant level of noise is added to the images. The method is then applied
to an experimental AC-STEM image of a Au55 nanocluster, a particularly challenging
case since the atomic structure is irregular. Analysis of the local structure shows that
the cluster is a combination of a part with icosahedral structure elements and a part with
local atomic arrangement characteristic of a crystal packing, including a segment of
a flat surface facet. The energy landscape of the cluster is explored in calculations of
minimum energy paths between the optimal fit structure and other candidates generated
in the analysis. This reveals low energy barriers for conformational changes, showing
that such transitions can occur on laboratory timescale even at room temperature and
lead to considerable changes in the AC-STEM image. Furthermore, the paths reveal
additional cluster configurations, some with lower DFT energy and providing nearly as
good fit to the experimental image.
Detailed analysis of AC-STEM images using theoretical modeling requires a reliable,
quantitative measure of the extent to which a simulated image agrees with an experimentally measured image. A simple sum of pixel-by-pixel squared errors turns out to
be unreliable and a more advanced measure is needed. A method based on the Speeded
Up Robust Features (SURF) algorithm is applied to match simulated images to an
experimental AC-STEM image of a Au55 nanocluster. The method provides a quantitative measure that more closely corresponds to a visual assessment of image similarityÁkvörðun á uppröðun atóma í nanóklösum er erfitt verkefni en mjög mikilvægt til
að öðlast skilning á efna- og eðlisfræðilegum eiginleikum þeirra. Nýleg mælitækni,
spegilvilluleiðrétt og skannandi gegnumlýsingar rafeindasmásjá (e. aberration corrected
scanning transmission electron microscope, AC-STEM) hefur gefið mikilvægar upplýsingar um slík kerfi. Þótt mælitækin séu háþróuð er úrvinnslan á mæligögnunum, sem
er tvívíð mynd af klasanum á atómskala, oft ónákvæm og ekki magnbundin enn sem
komið er. Í verkefninu er þróuð aðferðafræði til að vinna úr myndum sem koma úr
AC-STEM mælingum. Þar er mat á samræminu milli útreiknaðrar myndar við mældu
myndinarinnar ásamt mati á orku nanóklasans notað í bestunarreikningum til að ákvarða
hnit atómanna. Fyrst er aðferðin prófuð fyrir líkön af AC-STEM myndum fyrir bæði
reglulega og óreglulega Au55 nanóklasa. Ekki er nauðsynlegt að atómin myndi raðir í
klasanum og einnig er hægt að finna réttu hnitin þótt suð sé til staðar. Þá er aðferðinni
beitt á mælda AC-STEM mynd af Au55 klasa. Þetta er sérstaklega krefjandi dæmi því
staðsetning atómanna er óregluleg í þessum klasa. Greining á staðbundinni uppröðun
atómanna sýnir að klasinn er samsettur úr tveimur hlutum, annar með strúktúreiningar
sem einkenna íkósahedru og hinn dæmigerður fyrir atóm í kristal og þar er jafnframt að
finna bút af flötu yfirborði. Orkulandslag klasans er kannað með reikningum á lágmarksorkuferlum milli strúktúrsins sem gefur besta samsvörun við mælingarnar og annarra
strúktúra sem einnig sýna góða samsvörun. Í ljós kemur að orkuhólarnir milli þessara
strúktúra eru gjarnan lágir og slíkar umraðanir atómanna geta því greiðlega átt sér stað
á meðan á mælingunum stendur og þar með haft áhrif á AC-STEM myndina. Ferlarnir
leiða einnig í ljós nýja strúktúra sem sumir hafa lægri DFT orku og gefa næstum jafn
góða samsvörun við myndina sem fékkst með mælingunum. Ítarleg úrvinnsla á ACSTEM myndum með útreikningum fyrir líkön af strúktúrum krefst þess að áreiðanlegt
tölulegt mat sé hægt að leggja á hversu góð samsvörunin er. Í ljós kemur að einföld
summa af kvaðrati frávikanna í styrk allra dílanna á myndinni er ekki góður mælikvarði
á gæðin. Aðferð sem byggist á hraðaðri greiningu á afgerandi kennileitum (speeded up
robust features, SURF) er þróuð og notuð til að bera saman reiknaðar myndir og mælda
fyrir Au55 klasann. Þessi aðferð gefur magnbundið mat á samsvörunina sem samræmist
vel niðurstöðum sem fást við skoðun myndanna