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Fishing for Sustainability: Essays on the Economic, Social and Biological Outcomes of Fisheries Policy in the Faroe Islands
Get PDFFlestir fiskistofnar heims eru nýttir að fullu eða ofveiddir. Ofnýting hefur í för með sér slæmar vistfræðilegar, hagrænar og félagslegar afleiðingar. Minna er hægt að veiða úr ofveiddum stofnum og hætta getur verið á hruni þeirra. Og af því að þeir gefa minna af sér eru veiðarnar ekki jafn arðbærar og geta jafnvel verið reknar með tapi. Lélegt ástand stofnanna hefur áhrif á þá sem nýta auðlindina og það getur hoggið nærri brothættum sjávarbyggðum.
Í þessari doktorsritgerð er sjónum beint að Færeyjum. Íbúar Færeyja eru um 50 þúsund og þeir eiga mikið undir sjávarútvegi. Veiðar og vinnsla standa undir 24% af vergri landsframleiðslu (VLF) og útflutningur sjávarafurða svaraði til 52% af útflutningi ársins 2017. Um 10% fólks vinnur við sjávarútveg, þar af um 1.500 við veiðar og um 1.200 við vinnslu. En þrátt fyrir mikilvægi sjávarútvegs eru helstu fiskistofanar við Færeyjar ofnýttir.
Í fyrstu grein þessarar ritgerðar er fjallað um stjórn fiskveiða í Færeyjum og hvernig hún hefur þróast á árunum 1948-2018. Færeyingar hafa reynt ýmis konar fiskveiðistjórnarkerfi; opinn aðgang, skilyrtan aðgang, leyfiskerfi og framseljanlegar aflaheimildir, en frá árinu 1996 hefur verið beitt sóknarstýringu með dagatakmörkunum. Í greininni er bent á að stjórnun heimaflotans, sem veiðir úr stofnum við Færeyjar, hefur ekki verið nægjanlega aðhaldssöm og fyrir vikið hafa helstu fiskistofnar verið ofnýttir. Veiðarnar hafa jafnframt að mestu verið óarðbærar. Þessu er öfugt farið með stjórn úthafsflotans, sem veiðir á fjarlægum miðum, og uppsjávarveiðiskipa, en þeim hefur að mestu verið stjórnað með kvótakerfi. Þar hefur hagnaður verið meiri og viðvarandi.
Í annarri greininni er borinn saman líffræðilegur, hagrænn og félagslegur árangur af ólíkri stjórn veiða heimaflotans, uppsjávarflotans og úthafsflotans 1985-2018. Sýnt er fram á að vegna þess að fiskistofnar við Færeyjar voru ofnýttir og heimaflotinn of stór, hefur aldrei náð að myndast nein auðlindarentu í þeim veiðum. Í uppsjávarveiðum hefur á hinn bóginn orðið til allgóð auðlindarenta. Laun sjómanna á skipum og bátum í heimaflotanum hafa einnig verið lægri en á öðrum skipum og sum ár jafnvel lægri en meðallaun í Færeyjum. Fjárhagslegur stuðningur hins opinbera hefur aukið á vandann með því að viðhalda of stórum heimaflota og þannig ýtt undir ofnýtingu fiskistofna við eyjarnar.
Í þriðju greininni eru beitt aðferð sem kennd er við frammistöðumælikvarða (Fishery Performance Indicators, FPI) til að gaumgæfa frekar þróun fiskveiða í Færeyjum. Allar fiskveiðarnar sem samanburðurinn nær til fá góða einkunn á samfélagslegum skala, en togarar i heimaflotanum fá þó lakari einkunn en úthafsflotinn og uppsjávarveiðiflotinn. Heimatogararnir standa sig einnig verst í vistfræðilegu tilliti. Þótt góð auðlindarenta hafa myndast í uppsjávarveiðum stendur sá floti að baki hinum flotunum tveimur í hagrænum skilningi, einkum vegna þeirrar miklu óvissu sem fylgir stórum sveiflum í heildarafla. Greiningin sýnir einnig fram á að nýtingarréttur togskipa í heimaflotanum er veikur miðað við það sem gerist og gengur almennt í fiskveiðum í iðnvæddum löndum.
Í fjórðu og síðustu greininni er sagt frá þeim breytingum á stjórn fiskveiða í Færeyjum sem kynntar voru árið 2018, en með þeim var ætlunin að bæta líffræðilega og hagræna sjálfbærni veiðanna. Bent er á hvað gæti staðið í vegi fyrir því að þau áform gengu eftir, ekki síst þá staðreynd að umbæturnar áttu aðeins að ná til hluta heimaflotans. Því væri hætta á að breytingarnar myndu ekki hafa tilætluð áhrif og áfram yrði því bið á að hinir mikilvægu stofnar þorsks og ýsu í færeyskri lögsögu næðu að rétta úr kútnum.
Ritgerðin dregur fram að veiðum færeyska heimaflotans hefur ekki verið stjórnað á heppilegasta máta sem hefur haft vond líffræðileg, hagræn og félagsleg áhrif. Reynslan af stjórn veiða úthafsflotans og uppsjávarveiðiflotans sýnir glögglega hversu mikið sú óstjórn hefur kostað. Ritgerðin sýnir einnig að sá auður sem sjávarútvegur hefur skapað hefur átt þátt í að lyfta lífskjörum í Færeyjum. En þrátt fyrir mikilvægi sjávarútvegs í þjóðarbúskapnum og nauðsyn þess að stjórna fiskveiðum með skynsamlegum hætti hefur Færeyingum ekki lánast að gera sér meira úr auðlind sinni. Þær breytingar á stjórn fiskveiða, sem átti að hrinda í framkvæmd 2018, gengu heldur ekki nægjanlega langt. Þess vegna er mikilvægt að kannað verði hvernig hægt sé að ná samstöðu um stjórn veiða heimaflotans sem tryggi að til framtíðar verði veiðum á heimaslóð stjórnað með sjálfbærni að leiðarljósi.Most of the world’s fish stocks are overfished or fully fished. Overfishing has negative ecological, economic and social consequences. Fish stocks that are overfished produce less yield and may be at risk of collapse, and because they produce less yield, they are less profitable or not profitable at all. These negative consequences naturally affect the people who rely on the resource, whether for their livelihoods or for sustenance. Fisheries-dependent communities are naturally most affected by these negative consequences.
The case study area for this PhD thesis is the Faroe Islands. The Faroe Islands, a country of 50,000 people, located in the middle of the Northeast Atlantic, are highly dependent upon their fishing industry. The marine fishery accounted for 24% of the country’s Gross Domestic Product (GDP) and 52% of exports in 2017. The fishing industry is also an important source of employment, employing approximately 1,500 people in the catching sector and 1,200 in the processing sector, in total about 10% of the Faroese work force. Despite the importance of the fishing industry to the Faroe Islands, fish stocks in Faroese waters are overfished.
Paper I of this thesis explores the issue of fisheries policy in the Faroe Islands, describing and analysing how the Faroese have managed their fisheries in the period from 1948 through 2018. The Faroe Islands had five different management regimes in place in that period: open access; regulated open access; a licensing system; a brief period of individual transferable quotas; and, since 1996, an effort quota system, where the main control component comprised fishing days without total allowable catch control. The paper concludes that management of the home fleet has not effectively controlled effort, which has left the fish stocks in Faroese waters overexploited, the fleet overcapitalised, and the fishery largely unprofitable. This stands in contrast to management of the distant-water and pelagic fisheries, which have been managed predominantly with individual transferable quotas and, as a result, are more profitable and more sustainable.
In Paper II, data on economic, biological and social indicators are analysed to illustrate outcomes in the home fleet fisheries, the pelagic fishery, and the distant-water fishery in the period from 1985 to 2018. Outcomes are linked to the management frameworks in place. The paper concludes that due to overfishing and overcapacity, there was no resource rent in the home fleet fishery for a long time while the pelagic fishery especially generated large resource rents. The paper also concludes that fishers’ wages in the home fleet were lower than in the pelagic and distant-water fisheries, some years well below “normal” remuneration in the Faroe Islands. In addition to sub-optimal management, substantial fleet subsidies have exasperated the problem of overcapacity and thereby overfishing.
In Paper III, the Fishery Performance Indicators (FPI) framework, developed by Anderson et al. (2015), is applied to the three main fisheries in the Faroe Islands. With the FPI methodology, the paper measured triple bottom line outcomes—Ecology, Economics and Community—using 68 individual metrics across 14 dimensions. The results show that the three Faroese fisheries all scored high on the Community indicator but the home fleet trawlers scored lower than the other two fisheries due especially to a lower Career dimension score. The trawlers also had the lowest Ecology score. Despite generating large resource rent, the pelagic fleet had the lowest Economic score. This was predominantly due to poor Risk performance as a result of large volatility in the fishery. The analysis also revealed a notable lack of harvest rights in the home fishery for an industrialised fishery.
Paper IV describes and analyses the fisheries policy reform introduced in the Faroe Islands in 2018. The objectives of the reform were for fisheries to become biologically and economically sustainable but a number of barriers for success are identified, most notably that measures to ensure sustainability in the home fishery only apply to parts of the fleet, which may render them ineffective and hinder the much-needed recovery of the important cod and haddock stocks in Faroese waters.
This thesis draws attention to the fact that the home fleet fishery in the Faroe Islands has not been managed optimally and demonstrates the negative impact this has had on biological, economic and social outcomes. The outcomes in the pelagic and distant-water fisheries stand in contrast to this and illustrate the lost gains from mismanagement of the home fishery. The thesis also shows that wealth generated by the fishing industry has contributed to a high standard of living in the Faroe Islands, making sound management vitally important. For several decades, the Faroese have failed to capitalise on the potential wealth of the renewable natural resource within their EEZ, despite the importance of the resource to their economy. The fisheries policy reform does not adequately address failures in management and is unlikely to improve biological and economic outcomes in the home fleet. Future research should focus on how to reach a consensus on the management of the home fleet fishery to achieve lasting and sustainable change.Henda serritgerð kannar sambandið millum fiskivinnupolitikk og lívfrøðilig, búskaparlig og sosial úrslit í Føroyum. Hon er samansett av seks kapitlum, harav fýra greinum, innleiðing, og niðurstøðum. Tríggjar greinar er útgivnar av altjóða akademiskum tíðarritum og tann fjórða er latin til ummælis.
Tann fyrsta greinin lýsir og greinar føroyskan fiskivinnupolitikk frá 1948, tá heimastýrislógin kom í gildi og føroyingar yvirtóku málsøkið fiskivinna, til og við 2018. Í hesum tíðarskeiði vóru fimm ymiskar skipanir í gildi: frí atgongd, har ongar ásetingar vóru; skipað frí atgongd, har fáar ásetingar vóru; loyvisskipan; eitt stutt tíðarskeið við kvotuskipan; og fiskidagaskipanin, sum kom í gildi í 1996. Greinin kemur til ta niðurstøðu, at grundleggjandi veikleikar hava verið í umsitingini, ið hava ført til ovurfisking og yvirkapasitet. Umsitingin av uppisjóvarflotanum og fjarfiskaflotanum hinvegin hevur vart fiskastovnarnar betur og hevur ikki ført til yvirkapasitet á sama hátt.
Næsta greinin kannar lívfrøðiligu, búskaparligu og sosialu gongdina í føroyskari fiskivinnu millum 1985 og 2018 við at kanna lyklaindikatorar. Veiðuhagtøl benda á systematiska ovurfisking av botnfiskastovnunum. Greinin vísir eisini, at tað var so at siga eingin tilfeingisrenta í heimaflotanum hesi árini, meðan tilfeingisrentan í serliga uppisjóvarflotanum var stór. Lønirnar í heimaflotanum vóru eisini lágar, summi ár sera lágar. Vánalig búskaparlig og sosial úrslit eru allarhelst ein avleiðing av ovurfisking og yvirkapasiteti. Fíggjarligur stuðul til fiskivinnuna hevur gjørt trupulleikarnar við ovurfisking og yvirkapasiteti verri.
Tann triðja greinin kannar lívfrøðiligu, búskaparligu og sosialu støðuna í føroysku fiskivinnuni í 2017 við at brúka Fishery Performance Indicators háttalagi, ið Anderson et al. (2015) hava útviklað, og sum fevnir um 68 indikatorar. Sama háttalag er brúkt til at kanna fleiri enn 100 fiskivinnuskipanir. Niðurstøðurnar eru, at allir flotar høvdu góð sosial úrslit, men trolarar høvdu verri sosial og lívfrøðilig úrslit enn hinir, og uppisjóvarflotin, hóast stóra tilfeingisrentu, hevði verri búskaparlig úrslit, serliga vegna stórar broytingar í veiðumongdini, sum økir um váðan. Fjarfiskaflotin hevði bestu úrslitini.
Síðsta greinin lýsir og kannar fiskivinnunýskipanina, sum løgtingið samtykti í desembur 2017. Endamálið við nýskipanina var lívfrøðilig og búskaparlig burðardygd, men greinin vísir á, at fleiri forðingar eru fyri hesum í nýggju lógini. Serliga verður víst á, at tiltøk at betra um lívfrøðiliga burðardygd ikki eru galdandi fyri allan heimaflotan.EU Horizon 2020 Marie Skłodowska-Curie MSCA-ETN Programme (project 642080
Characterization and diversity of the complete set of GH family 3 enzymes from Rhodothermus marinus DSM 4253
Get PDFPublisher's version (útgefin grein)The genome of Rhodothermus marinus DSM 4253 encodes six glycoside hydrolases (GH) classified under GH family 3 (GH3): RmBgl3A, RmBgl3B, RmBgl3C, RmXyl3A, RmXyl3B and RmNag3. The biochemical function, modelled 3D-structure, gene cluster and evolutionary relationships of each of these enzymes were studied. The six enzymes were clustered into three major evolutionary lineages of GH3: β-N-acetyl-glucosaminidases, β-1,4-glucosidases/β-xylosidases and macrolide β-glucosidases. The RmNag3 with additional β-lactamase domain clustered with the deepest rooted GH3-lineage of β-N-acetyl-glucosaminidases and was active on acetyl-chitooligosaccharides. RmBgl3B displayed β-1,4-glucosidase activity and was the only representative of the lineage clustered with macrolide β-glucosidases from Actinomycetes. The β-xylosidases, RmXyl3A and RmXyl3B, and the β-glucosidases RmBgl3A and RmBgl3C clustered within the major β-glucosidases/β-xylosidases evolutionary lineage. RmXyl3A and RmXyl3B showed β-xylosidase activity with different specificities for para-nitrophenyl (pNP)-linked substrates and xylooligosaccharides. RmBgl3A displayed β-1,4-glucosidase/β-xylosidase activity while RmBgl3C was active on pNP-β-Glc and β-1,3-1,4-linked glucosyl disaccharides. Putative polysaccharide utilization gene clusters were also investigated for both R. marinus DSM 4253 and DSM 4252T (homolog strain). The analysis showed that in the homolog strain DSM 4252TRmar_1080 (RmXyl3A) and Rmar_1081 (RmXyl3B) are parts of a putative polysaccharide utilization locus (PUL) for xylan utilization.Support from the Swedish research council Formas (Grant 2015-769), the BBI, Horizon 2020 project “Macro Cascade” and the Era-nets MBT “Thermofactories” and SusFood2 “ProSeaFood” as well as the NovoNordisk Grant (NNF18OC0034792) is greatly appreciated.Peer Reviewe
Empirical relationships between bone density and ultimate strength: A literature review
Get PDFPublisher's version (útgefin grein)Introduction: Ultimate strength-density relationships for bone have been reported with widely varying results. Reliable bone strength predictions are crucial for many applications that aim to assess bone failure. Bone density and bone morphology have been proposed to explain most of the variance in measured bone strength. If this holds true, it could lead to the derivation of a single ultimate strength-density-morphology relationship for all anatomical sites. Methods: All relevant literature was reviewed. Ultimate strength-density relationships derived from mechanical testing of human bone tissue were included. The reported relationships were translated to ultimate strength-apparent density relationships and normalized with respect to strain rate. Results were grouped based on bone tissue type (cancellous or cortical), anatomical site, and loading mode (tension vs. compression). When possible, the relationships were compared to existing ultimate strength-density-morphology relationships. Results: Relationships that considered bone density and morphology covered the full spectrum of eight-fold inter-study difference in reported compressive ultimate strength-density relationships for trabecular bone. This was true for studies that tested specimens in different loading direction and tissue from different anatomical sites. Sparse data was found for ultimate strength-density relationships in tension and for cortical bone properties transverse to the main loading axis of the bone. Conclusions: Ultimate strength-density-morphology relationships could explain measured strength across anatomical sites and loading directions. We recommend testing of bone specimens in other directions than along the main trabecular alignment and to include bone morphology in studies that investigate bone material properties. The lack of tensile strength data did not allow for drawing conclusions on ultimate strength-density-morphology relationships. Further studies are needed. Ideally, these studies would investigate both tensile and compressive strength-density relationships, including morphology, to close this gap and lead to more accurate evaluation of bone failure.This study was supported by the grant #2018-430 of the Strategic Focal Area “Personized Health and Related Technologies” of the ETH Domain, ETH Zurich , Switzerland and the St. Josef ‘s Hospital Fund , Reykjavik, Iceland.Peer Reviewe
Why do RuO2 electrodes catalyze electrochemical CO2 reduction to methanol rather than methane or perhaps neither of those?
No full textPublisher's version (útgefin grein)The electrochemical CO2reduction reaction (CO2RR) on RuO2and RuO2-based electrodes has been shown experimentally to produce high yields of methanol, formic acid and/or hydrogen while methane formation is not detected. This CO2RR selectivity on RuO2is in stark contrast to copper metal electrodes that produce methane and hydrogen in the highest yields whereas methanol is only formed in trace amounts. Density functional theory calculations on RuO2(110) where only adsorption free energies of intermediate species are considered,i.e.solvent effects and energy barriers are not included, predict however, that the overpotential and the potential limiting step for both methanol and methane are the same. In this work, we use bothab initiomolecular dynamics simulations at room temperature and total energy calculations to improve the model system and methodology by including both explicit solvation effects and calculations of proton-electron transfer energy barriers to elucidate the reaction mechanism towards several CO2RR products: methanol, methane, formic acid, CO and methanediol, as well as for the competing H2evolution. We observe a significant difference in energy barriers towards methane and methanol, where a substantially larger energy barrier is calculated towards methane formation than towards methanol formation, explaining why methanol has been detected experimentally but not methane. Furthermore, the calculations show why RuO2also catalyzes the CO2RR towards formic acid and not CO(g) and methanediol, in agreement with experimental results. However, our calculations predict RuO2to be much more selective towards H2formation than for the CO2RR at any applied potential. Only when a large overpotential of around −1 V is applied, can both formic acid and methanol be evolved, but low faradaic efficiency is predicted because of the more facile H2formation.This work was supported by the Icelandic Research Fund (grant no. 196437-051), the Research Fund of the University of Iceland and the ‘Nordic Consortium for CO2 Conversion’ (NordForsk project no. 85378, http://site.uit.no/nordco2).Peer Reviewe
Stakeholder Perceptions of Policy Tools in Support of Sustainable Food Consumption in Europe: Policy Implications
Get PDFPublisher's version (útgefin grein)Transitioning agri-food systems towards increased sustainability and resilience requires that attention be paid to sustainable food consumption policies. Policy-making processes often require the engagement and acceptance of key stakeholders. This study analyses stakeholders' solutions for creating sustainable agri-food systems, through interviews with a broad range of stakeholders including food value chain actors, non-governmental organizations, governmental institutions, research institutions and academic experts. The study draws on 38 in-depth, semi-structured interviews conducted in four European countries: France, Iceland, Italy and the UK, as well as three interviews with high-level EU experts. The interviewees' solutions were analysed according to a five-category typology of policy tools, encompassing direct activity regulations, and market-based, knowledge-based, governance and strategic policy tools. Most of the identified solutions were located in the strategic tools category, reflecting shared recognition of the need to integrate food policy to achieve long-term goals. Emerging solutions-those which were most commonly identified among the different national contexts-were then used to derive empirically-grounded and more universally applicable recommendations for the advancement of sustainable food consumption policies.The VALUMICS project "Understanding Food Value Chain and Network Dynamics" received funding from the European Union's Horizon 2020 research and innovation programme, under grant agreement No. 727243. https://valumics.eu/. The authors would like to thank the interviewees for their participation in this study, and the two anonymous reviewers for providing useful comments.Peer Reviewe
Current Status and Future Prospects of Genome-Scale Metabolic Modeling to Optimize the Use of Mesenchymal Stem Cells in Regenerative Medicine
Get PDFPublisher's version (útgefin grein)Mesenchymal stem cells are a promising source for externally grown tissue replacements and patient-specific immunomodulatory treatments. This promise has not yet been fulfilled in part due to production scaling issues and the need to maintain the correct phenotype after re-implantation. One aspect of extracorporeal growth that may be manipulated to optimize cell growth and differentiation is metabolism. The metabolism of MSCs changes during and in response to differentiation and immunomodulatory changes. MSC metabolism may be linked to functional differences but how this occurs and influences MSC function remains unclear. Understanding how MSC metabolism relates to cell function is however important as metabolite availability and environmental circumstances in the body may affect the success of implantation. Genome-scale constraint based metabolic modeling can be used as a tool to fill gaps in knowledge of MSC metabolism, acting as a framework to integrate and understand various data types (e.g., genomic, transcriptomic and metabolomic). These approaches have long been used to optimize the growth and productivity of bacterial production systems and are being increasingly used to provide insights into human health research. Production of tissue for implantation using MSCs requires both optimized production of cell mass and the understanding of the patient and phenotype specific metabolic situation. This review considers the current knowledge of MSC metabolism and how it may be optimized along with the current and future uses of genome scale constraint based metabolic modeling to further this aim.The Icelandic Research Fund (grant number 217005) and by the Institute for Systems Biology's Translational Research Fellows Program (JY)."Peer Reviewed
Do black‐backed jackals exhibit spatial partitioning with African wild dogs and lions?
Get PDFPublisher's version (útgefin grein)We thank Global Vision International, J. Power, W. Collinson and K. Potgieter-Forssman for help with tracking the radio-collared animals. This project was an initiative of the Carnivore Conservation Programme of the Endangered Wildlife Trust, South Africa, and the Wildlife Conservation Research Unit, Oxford University, U.K. Funding for J.F.K. was provided by a Research Fellowship from the Wildlife Conservation Society, New York, and a Marie Curie Fellowship from the European Commission, Brussels, Belgium. Sponsorship was provided by Jaguar Land Rover South Africa and De Beers Consolidated Mines.Peer Reviewe
Effect of vaccination on the use of antimicrobial agents: a systematic literature review
Get PDFPublisher's version (útgefin grein)Background: Antimicrobial resistance is a growing global health threat. To preserve the effectiveness of antimicrobials, it is important to reduce demand for antimicrobials. Objectives: The objective of the study was to screen the existing peer-reviewed literature to identify articles that addressed the potential impact of influenza or Pneumococcus vaccination on antibiotic usage. Data sources: PubMed, Embase Study eligibility criteria: Clinical studies where antimicrobial prescribing was assessed in both vaccinated and unvaccinated populations. Participants and interventions: All patient populations were included (infants, children, adults and elderly), where the effects of the intervention (vaccination) was assessed Results: We identified unique 3638 publications, of which 26 were judged to be of sufficiently high quality to allow the calculation of the potential impact of vaccination. Of these studies 23/26 found a significant reduction in antibiotic use by at least one of the parameters assessed. Limitations: Different measures used to define anti-microbial use, studies typically focus on specific risk groups and most studies are from high-income countries. Conclusions and implications of key findings: Despite the limitations of the review, the evidence indicates that improved coverage with existing vaccines may significantly reduce antimicrobial demand. This suggests it may be a valuable tool for antimicrobial stewardship.Key messages While vaccines against a number of pathogens have been studied for their ability to reduce antimicrobial use, currently only vaccination against influenza or pneumococcus has generated sufficient data for analysis Vaccination against either influenza or pneumococcus significantly reduced overall antimicrobial prescribing rates, both in vaccinated individuals and at a population level Maintaining and expanding vaccination coverage thus appears to be a key tool for antimicrobial stewardship.GlaxoSmithKline Biologicals S.A. funded the independent assessment by Pallas and all costs related to the development of this review article, but did not provide payment to the authors.Peer Reviewe
Improved long‐span bridge modeling using data‐driven identification of vehicle‐induced vibrations
Get PDFPublisher's version (útgefin grein)The paper introduces a procedure to automatically identify key vehicle characteristics from vibrations data collected on a suspension bridge. The primary goal is to apply a model of the dynamic displacement response of a long-span suspension bridge to traffic loading, suitable for automatic identification of the vehicle passage over the bridge. The second goal is to improve the estimation of the structural damping of the bridge deck by utilizing the free-decay displacement response induced by the passing vehicles. The vehicles responsible for a significant bridge vertical response are first identified using an outlier analysis and a clustering algorithm. Utilizing a moving mass model, the equivalent mass and speed of each vehicle, as well as its arrival time, are assessed in a least-squares sense. The computed vertical displacement response shows a remarkably good agreement with the full-scale data in terms of peak values and root-mean-square values of the displacement histories. The data acquired on the Lysefjord Bridge (Norway) indicate that the contribution of heavy traffic loading to the combined effects of wind and traffic excitation may be significant even at mean wind speeds above 10 m s(-1). The critical damping ratios of the most significant vibrational modes of the Lysefjord Bridge are studied for low wind velocities, using the time-decomposition technique and the traffic-induced free-decay response of the bridge deck. The structural damping ratios estimated this way are found to be more accurate than those obtained with an automated covariance-driven stochastic subspace identification algorithm applied to the same dataset.Norwegian Public Roads Administration"Peer Reviewed
Transcriptional responses in Parascaris univalens after in vitro exposure to ivermectin, pyrantel citrate and thiabendazole
Get PDFPublisher's version (útgefin grein)Background: Parascaris univalens is a pathogenic parasite of foals and yearlings worldwide. In recent years, Parascaris spp. worms have developed resistance to several of the commonly used anthelmintics, though currently the mechanisms behind this development are unknown. The aim of this study was to investigate the transcriptional responses in adult P. univalens worms after in vitro exposure to different concentrations of three anthelmintic drugs, focusing on drug targets and drug metabolising pathways. Methods: Adult worms were collected from the intestines of two foals at slaughter. The foals were naturally infected and had never been treated with anthelmintics. Worms were incubated in cell culture media containing different concentrations of either ivermectin (10-9 M, 10-11 M, 10-13 M), pyrantel citrate (10-6 M, 10-8 M, 10-10 M), thiabendazole (10-5 M, 10-7 M, 10-9 M) or without anthelmintics (control) at 37 °C for 24 h. After incubation, the viability of the worms was assessed and RNA extracted from the anterior region of 36 worms and sequenced on an Illumina NovaSeq 6000 system. Results: All worms were alive at the end of the incubation but showed varying degrees of viability depending on the drug and concentration used. Differential expression (Padj < 0.05 and log2 fold change ≥ 1 or ≤ - 1) analysis showed similarities and differences in the transcriptional response after exposure to the different drug classes. Candidate genes upregulated or downregulated in drug exposed worms include members of the phase I metabolic pathway short-chain dehydrogenase/reductase superfamily (SDR), flavin containing monooxygenase superfamily (FMO) and cytochrome P450-family (CYP), as well as members of the membrane transporters major facilitator superfamily (MFS) and solute carrier superfamily (SLC). Generally, different targets of the anthelmintics used were found to be upregulated and downregulated in an unspecific pattern after drug exposure, apart from the GABA receptor subunit lgc-37, which was upregulated only in worms exposed to 10-9 M of ivermectin. Conclusions: To our knowledge, this is the first time the expression of lgc-37 and members of the FMO, SDR, MFS and SLC superfamilies have been described in P. univalens and future work should be focused on characterising these candidate genes to further explore their potential involvement in drug metabolism and anthelmintic resistance.[Figure not available: see fulltext.]This work was supported by the Swedish research council FORMAS (grant no. 942-2015-508).Peer Reviewe