Háskólinn á Akureyri

Varanleg URI fyrir þennan undirflokkhttps://hdl.handle.net/20.500.11815/5666

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Niðurstöður 1 - 20 af 330

Winter fluxes determine the annual carbon balance of an unmanaged subarctic drained peatland
(2026-06-22) Salimi, Asra; Sigurdsson, Bjarni D.; Bjarnadottir, Brynhildur; Feng, Chenxin; Óskarsson, Hlynur; Mammarella, Ivan; Faculty of Education
Peatlands are critical components of the global carbon (C) cycle, storing large amounts of soil organic carbon (SOC). However, drainage substantially alters their carbon exchange and hydrological functioning, often converting them into net carbon dioxide (CO2) sources. This study presents the first year-round, ecosystem-scale Eddy Covariance (EC) assessment of CO2 dynamics from an unmanaged drained peatland in western Iceland, originally drained in the early 1960s. Two years of continuous EC measurements were collected alongside high-resolution environmental data, including solar radiation, air and soil temperatures, soil water content, and groundwater level. Several multispectral drone flights were also conducted during the study period, which provided seasonal NDVI-based estimates of canopy greenness. The two study years differed markedly in annual weather during the growing season (GS), with 2023 GS being unusually warm and dry, while 2024 GS was cold and wet. Despite these contrasts, annual net ecosystem exchange (NEE) remained similar between the 2 years. The annual NEE was dominated by non-growing-season (NGS) respiration, which highlighted the necessity for year-round measurements. Overall, the site remained a persistent CO2 source, emitting 4.1–4.4 tCO2-Cha-1 yr-1 nearly 60 years after drainage. Temperature exerted the strongest control on ecosystem respiration (Reco), while gross primary production (GPP) responded primarily to seasonal irradiance and NDVI. A compensatory mechanism was observed during the warm year (2023) at this relatively cool site, where warming-induced increases in Reco were offset by an enhanced GPP, resulting in a relatively stable annual NEE despite meteorological contrasts. Soil moisture and vapor pressure deficit played only minor roles under these cool and moist conditions. These findings highlight the need for continued monitoring of unmanaged drained peatlands to better quantify their contribution to regional greenhouse gas budgets.
Proteomic characterization of Lysinibacillus reveals early-stage PET biodegradation potential
(2026-03-24) Dudziak, Radoslaw B.; Muñoz-Hisado, Víctor; Hidalgo-Arias, Andrea; Martínez-Carrancho, María; Garcia-Lopez, Eva; Fakhouri, Farayde Matta; Martinez-Alonso, Emma; Alcázar, Alberto; Sigurbjörnsdóttir, Margrét Auður; Fonseca, Gustavo Graciano; Cid, Cristina; Faculty of Natural Resource Sciences
Plastic pollution is a global challenge due to the persistence of synthetic polymers such as polyethylene terephthalate (PET) and the limited efficiency of current recycling strategies. While microbial biodegradation is a promising alternative, the relatively recent introduction of plastics has constrained microbial evolutionary adaptation and enzymatic efficiency. In this study, a PET-associated bacterial strain was isolated from Icelandic soil, identified as Lysinibacillus sp. via 16S rRNA sequencing, and evaluated through growth assays, proteomics, in silico screening, and surface imaging. In mineral medium with PET as the sole carbon source, Lysinibacillus sp. exhibited a shorter lag phase and higher early-stage growth than the reference strain Ideonella sakaiensis (p < 0.05 at Weeks 1, 2, 4, and 6) over six weeks. FE-SEM revealed microbial colonization, surface erosion, fissures, and delamination, indicating polymer surface alteration. MALDI-TOF MS proteomic analysis did not detect canonical PET-degrading enzymes such as PETase or MHETase. The in silico genome-wide screen similarly failed to identify PETases or other known polyester hydrolases carrying the conserved GXSXG motif, the Ser-His-Asp catalytic triad, or compatible α/β-hydrolase domain architecture. Instead, PET exposure triggered metabolic reprogramming dominated by oxidative-stress response proteins (peroxiredoxins, superoxide dismutases, thiol peroxidases) and central metabolic enzymes. Although several proteins annotated as hydrolases were expressed, these lacked the catalytic signatures and structural features characteristic of validated PET-degrading polyesterases. Taken together, the proteomic and in silico results indicate that Lysinibacillus sp. responds to PET through broad metabolic and oxidative-stress adaptation rather than through expression of dedicated PET-hydrolyzing enzymes. This stress-driven remodeling may support limited transformation of PET-associated compounds but does not constitute evidence of direct PET depolymerization. The rapid adaptive response of Lysinibacillus sp. complements the slower, enzyme-driven strategy of I. sakaiensis, supporting the potential of microbial consortia for multi-stage plastic biodegradation.
Building people-centred organisational resilience in remote and highly seasonal tourism
(2026-05) Karlsdóttir, Verena; Faculty of Business Administration
Tourism and hospitality organisations in remote, highly seasonal Arctic and sub-Arctic destinations face persistent workforce instability, multicultural team dynamics, and well-being risks that threaten service reliability and organisational continuity. Previous research has focused mainly on destination- and community-level resilience, while giving less attention to how resilience is built within tourism organisations through everyday workforce-related practices. This study examines people-centred organisational resilience through a qualitative comparative design in two northern contexts: Iceland and Finnish Lapland. The empirical material comprised semi-structured interviews in Iceland and interviews, organisational documents, and field observations in Finnish Lapland, collected in autumn 2025. The data were analysed using thematic analysis. The findings identify four recurring resilience mechanisms: leadership under seasonal and environmental pressure; employee experience across employment phases; living conditions and belonging; and ethical governance. Here, “mechanisms” refers not simply to broad topics but to organisational processes through which recurring practices support resilience in remote, highly seasonal tourism settings. Together, these mechanisms show that resilience in remote tourism is built not only through operational flexibility or crisis response, but through people-centred organisational practices that support continuity, coordination, safety, and trust across seasons. The study contributes a workforce-centred extension of resilience theory in tourism and offers a comparative account of how these mechanisms operate across two northern tourism settings.
Regenerative wellbeing in Arctic tourism : Sense of place and community resilience
(Academic Conferences and Publishing International Limited, 2026) Karlsdóttir, Verena; Patuleia, Mafalda; Faculty of Business Administration
As Arctic and sub-Arcticdestinations faceincreasing environmental, climatic, and social pressures, the tourism sector is being reimagined as aregenerative system that restores both human and ecological well-being. To u r i s m no longer serves just as an economic driver but as a catalyst for community resilience, cultural continuity, and care for the environment. This paper examines how nature-based and community-driven tourism in Iceland and Finnish Lapland cultivates resilience through a shared sense of place and explores how wellbeingcan emerge as a collective, place-based achievement. Drawing on comparative qualitative research involving tourismorganisations from Iceland and Lapland, the studyinvestigates how tourismorganisations embed local values, environmental respect, and care for people and place within their daily operations. The analysis highlights that the natural environment functions not only as the leading tourismattraction but also as a psychological, social, and cultural (re-)source for employees and residents. In both regions, connection with nature strengthens emotional resilience, job satisfaction, and commitment to sustainable practices, while also reinforcing a deeper understanding ofArctic fragility andinterdependence. Leaders who integrate empathy, learning, and trustinto their management styles promote supportive, value-driven workplaces that mirror the patterns of local settings. Community collaboration, storytelling, and shared outdoor experiences enhance belonging and stability, transforming tourismfrom seasonal employmentinto participationin living cultural ecosystems. The research demonstrates thatregenerative wellbeing in tourismemerges when organisations align their operations with the ecological and cultural identity of their environment. In Iceland, this manifests through locally rooted entrepreneurship and community stewardship; in Lapland, through multicultural collaboration and a shared Arcticidentity constructed through work in extreme environments. Both regions illustrate how tourismcan move beyond sustainability toward the active renewal of ecosystems, cultural heritage, and human connection. By situating the sense of place and well-being at the centre of regenerativetourism, the paper contributes a framework linking leadership, culture, and community resilience.
Antimicrobial resistance in the Nordics : Mapping existing surveillance systems and assessing the impact of COVID-19 using regression models
(2025-12) Tran, Tam T.; Krolicka, Adriana; Tiwari, Ananda; Pitkänen, Tarja; Lood, Rolf; Ásmundsdóttir, Ásta Margrét; Wikmark, Odd Gunnar; Faculty of Natural Resource Sciences
Background: Coronavirus disease 2019 (COVID-19) pandemic constituted the largest global health crisis in recent generations. It may also have disrupted the pattern of antimicrobial use (AMU) and subsequently affected the development of antimicrobial resistance (AMR) – a grave human health concern. This study aimed to give an overview of existing AMR surveillance systems and evaluate the impact of COVID-19 on AMU and AMR in the Nordics using data from these systems. Methods: Nordic AMU data (2017–2022) were extracted from national annual reports (for both humans and animals) and the European Surveillance System (TESSy) (for humans only). For humans, AMU was expressed in defined daily dose (DDD) per 1000 inhabitants per day; for animals, it was expressed in kilogram (kg). Nordic human AMR data (2017–2022) were extracted from TESSy. Multilevel linear regression and negative binomial regression models were used to fit the TESSy data. Data between 2017 and 2019 were categorised as the pre-COVID-19 time, while data between 2020 and 2022 were the per-COVID-19 time. Results: Denmark had a remarkably greater AMU in animals (about 10 times greater) than Norway, Sweden, and Finland. Iceland had the highest human AMU, while Sweden had the lowest. Drug categories, countries, and sectors were significant predictors in the model used to fit human AMU. Bacterial species and drug categories were significant predictors in the models used to fit human resistant Gram-negative and Gram-positive bacteria. The COVID-19 time was not a significant predictor in these models. Among the Nordics, Iceland had the lowest number of resistant isolates; however, high human AMU remains a great concern for Iceland. Conclusions: The study provided insight into current existing AMR surveillance systems in the Nordics. It also showed that the COVID-19 pandemic had very little impact on AMU and AMR in theses countries. This implied that strict regulations on AMU as well as well-coordinated national AMR surveillance systems in the Nordics mitigated the development of AMR crisis also during COVID-19 pandemic. However, the Nordics would still benefit further from a standardized AMR surveillance at regional level, which ultimately facilitate timely information sharing and improve our preparedness for and response to future pandemics and/or large-scale outbreaks.
Stability of EEG-Biometrics : The role of artifacts in within vs. cross session authentication
(2026) Höller, Yvonne; Bathke, Arne C.; Uhl, Andreas; Faculty of Psychology
Artifacts in the electroencephalogram (EEG) have not been investigated systematically regarding their effect on EEG biometric performance. Since artifacts vary over time, they can be expected to lower EEG biometric performance in cross session cross-validation. However, because of their presumed uniqueness, they might increase within session cross-validation performance of an EEG biometric system. We examined the EEG biometric performance of 15 features within and across 6 sessions recorded over 3 days, including 3 different cognitive conditions, before and after artifact exclusion in a sample of up to 90 individuals. Our results revealed significant effects of artifact exclusion depending on the cross-validation scenario and the feature. Overall, within session cross-validation was not systematically affected differently by artifact exclusion as compared to cross session cross-validation, but depending on the feature and the type of cognitive task employed, artifact exclusion led to better or worse results, with some frequency-dependent features performing better when artifacts were excluded. Our results emphasize the overestimation of biometric performance in within session cross-validation (with equal error rates (EERs) down to 0) as compared to cross session cross-validation (with EERs for the same feature above 30) and the low reliability of results obtained when evaluating EEG biometric performance in small samples. We recommend that future developments of EEG biometrics must test their robustness against artifacts in the data.
Stratification and mixed layer depth around Iceland : Characterization and inter-annual variability
(2026-05-29) Ruiz-Angulo, Angel; Portela, Esther; de Marez, Charly; Macrander, Andreas; Ólafsdóttir, Sólveig Rósa; Meunier, Thomas; Jónsson, Steingrímur; Pérez-Hernández, M. Dolores; Faculty of Natural Resource Sciences
The ocean around Iceland is a key region where major water masses and currents interact, influencing the global ocean circulation. Here, we analyze 29 years (1990–2019) of quarterly hydrographic section data collected around Iceland. The hydrographic properties around Iceland show important spatial variability. Based on temperature, salinity, and stratification structure, we classified the Icelandic waters in three distinct regions: the south, the north, and northeast regions. The warm and salty Atlantic Waters that dominate the south show the deepest winter mixed layers (∼ 500 m) while the north and northeast show shallower depths (∼ 100 m). Based on the decomposition of total stratification into temperature and salinity contributions, we find that the subsurface stratification is mainly controlled by temperature in the south and by salinity in the northwest, while in the north, the North Icelandic Irminger Current and East Icelandic Current alternate seasonally, shifting the region between temperature-dominated and salinity-dominated stratification. The interannual variability of the mixed layer and of its thermohaline properties is also large around Iceland. Mixed layer waters were generally colder in the 1990's, then warmed until approximately 2015, and became colder again from 2015 to 2018. In the northeast, a multidecadal mixed layer warming trend emerges from the interannual variability as the Atlantic Water progresses northeastward, which is responsible for transforming locally the upper stratification from salinity-dominated into temperature-dominated. This is associated with the “Atlantification” of the Arctic. Within the mixed layer south of Iceland, density has continuously decreased since the mid 1990's. Elsewhere, we observe density-compensated changes in mixed layer temperature and salinity, without clear long trends. This study provides an unprecedented and detailed description of the seasonal to multi-decadal variability of the mixed layer depth and stratification around Iceland, showing links between this regional variability and changing North Atlantic under global warming.
Testing quality indicators for physician-staffed fixed-wing air medical services in Iceland
(2025-03-01) Árnadóttir, María Kristbjörg; Gunnarsson, Björn; Haugland, Helge; School of Health, Business and Natural Sciences
Objective: Medical evacuation with fixed-wing air ambulances and rescue helicopters plays an important role in Iceland's emergency medical services. The objective of this study was to measure the quality of physician-staffed fixed-wing air ambulance services in Iceland using the 15 response-specific quality indicators (QIs) developed by the EQUIPE consensus group in Scandinavia. Methods: Physicians working in the Icelandic fixed-wing air ambulance service were asked to register response-specific QIs in an online questionnaire after every physician-staffed patient transport undertaken by the service from March 1 to December 31, 2023. Results: The fixed-wing air ambulance service in Iceland did not reach the benchmarks proposed by EQUIPE in 11 of 15 QIs tested. Furthermore, 7 QIs fell in the low performance zone and 4 in the average performance zone. Conclusion: Sparse population density, long transports, and the lack of a single prehospital organizational structure are challenging for Icelandic physician-staffed emergency medical services. This is, to our knowledge, the first time that the quality of the service has been assessed from other perspectives than time and mortality alone. As a result, several areas in need of improvement have been identified in our study.
Selection of helicopter bases and transport modes to minimize pre-hospital times in Iceland
(2025-12) Nguyen, Phuong; Dúason, Sveinbjörn; Gunnarsson, Björn; Ingólfsson, Ármann; School of Health, Business and Natural Sciences
Background: Models for the optimal location of ambulance bases typically focus on response time, but for some patients (e.g., trauma), the total pre-hospital time may matter more. Iceland’s geography and population distribution imply that fixed-wing air ambulances are an important mode for transporting emergency patients to one of the small number of hospitals with capabilities to treat patients with time-sensitive conditions. Helicopter ambulances have the potential to improve service for incidents that occur far from the closest airport. Methods: We formulate models to find optimal helicopter base locations with a primary objective of maximizing incident coverage and secondary objective of minimizing patient transport costs. Our models consider three transport modes (ground, fixed-wing, and helicopter), and evaluate the addition of new helicopter bases to a single existing fixed-wing base, single existing helicopter base, and multiple existing ground ambulance bases. Results: Akureyri and Flúðir are potential locations for a second helicopter base. These locations provide similar overall coverage levels, but effectiveness depends on hospital destination assumptions. Flúðir offers greater benefits if all patients are transported to Reykjavík Hospital, whereas Akureyri performs better if patients are transported to the nearest hospital. Conclusions: The choice of helicopter base locations depends on factors beyond coverage. Our work shows how optimization models can reveal the impact of operational assumptions on optimal base selection and illustrates a methodology that can be adapted for other countries facing similar geographic challenges.
Antibiotic resistance genes, antibiotic residues, and microplastics in influent and effluent wastewater from treatment plants in Norway, Iceland, and Finland
(2025-11-15) Tiwari, Ananda; Jaén-Gil, Adrián; Karavaeva, Anastasia; Gomiero, Alessio; Ásmundsdóttir, Ásta Margrét; Silva, Maria João; Salmivirta, Elisa; Tran, Tam T.; Sarekoski, Anniina; Cook, Jeremy; Lood, Rolf; Pitkänen, Tarja; Krolicka, Adriana; Faculty of Natural Resource Sciences
Monitoring antimicrobial resistance genes (ARGs) in wastewater influents (pre-treatment) and effluents (post-treatment) provides insights into community-level circulation, potential amplification during treatment, and risks associated with gene release into surface waters. Pollutants such as antibiotic residues and microplastics (MPs) may influence ARG dynamics, highlighting the need to assess their dynamics across wastewater environments. In this study, we analyzed ARGs and bacterial communities using Oxford Nanopore (ONP) metagenomics and qPCR in wastewater samples from Mekjarvik (Norway), Reykjavik (Iceland), and Mariehamn (Åland, Finland). Antibiotic residues were quantified via high-performance liquid chromatography (HPLC), and MPs were characterized using micro-fourier transform infrared spectroscopy (μ-FTIR) in Mekjarvik and Reykjavik. Metagenomic analysis identified 193 unique ARGs, with the highest average (±SD) in Reykjavik (66.3 ± 4.1), followed by Mekjarvik (61.3 ± 14.1) and Mariehamn (18.0 ± 2.2). ONP sequencing revealed that many ARGs were plasmid-associated, co-occurring with metal stress genes. Common plasmids were Col440I, IncQ2, and ColRNAI. Mercury-related genes dominated metal stress genes (64.9 %), followed by multimetal (23.7 %) and copper (6.4 %). Of 45 antibiotics screened, only sulfamethoxazole and sulfapyridine were consistently detected. Polyethylene (∼60 %) was the dominant MP type; Reykjavik influent had the highest MP load (8200 MP/m3). While treatment reduced ARGs, antibiotic residues, and larger MPs, it was less effective against fine particles and key ARGs, including carbapenemase- and ESBL-associated genes. Clinically relevant ARGs and potential pathogens (e.g., Acinetobacter baumannii, Pseudomonas aeruginosa) persisted in effluents, highlighting risks to downstream ecosystems. These findings underscore the need for regular monitoring of both influents and effluents to assess treatment performance and safeguard environmental health.
Bioactive compounds, antioxidant activity, and maturation effects in bitter and sweet orange juices
(2025-05-05) Cavenaghi-Altemio, Angela Dulce; Martelli, Silvia Maria; Fonseca, Gustavo Graciano; Faculty of Natural Resource Sciences
Bitter oranges (Citrus aurantium) and sweet oranges (Citrus sinensis) are commercially important citrus fruits with distinct uses and characteristics. Bitter oranges, primarily used as a flavoring agent, are rich in bioactive compounds, while sweet oranges dominate global citrus juice production. This study evaluated bitter orange juice at three maturation stages, comparing its physical, chemical, and bioactive properties with pasteurized pear orange juice (C. sinensis). Parameters assessed included water activity, pH, total titratable acidity, total soluble solids, maturation index, vitamin C content, total phenolic (TP) content, total flavonoid (TF) content, and antioxidant activity. The results showed that the vitamin C content in bitter oranges decreased with ripening but remained comparable to pear orange juice in the ripe stage. TPs and TFs were highest in pasteurized pear orange juice, reflecting the stability of these compounds during thermal processing. The antioxidant activity varied significantly across bitter orange maturation stages, with intermediate fruits demonstrating the strongest capacity. However, the maturation stage had limited influence on the antioxidant activity compared to pear orange juice. Bitter orange juices, despite being less commercially prominent, offer distinct bioactive advantages and antioxidant potential. Future research should explore optimizing maturation and processing methods to enhance the nutritional and functional properties of bitter orange juices.
Per- and polyfluoroalkyl substances (PFASs) meet Arctic and sub-Arctic marine diatoms and associated symbionts
(Háskólinn á Akureyri, 2026-10) Arulananthan, Ashani; Vilhelmsson, Oddur Þór; Scholz, Bettina; Sigurbjörnsdóttir, Margrét Auður; Rolfsson, Óttar; Grossart, Hans Peter; Karsten, Ulf; Centre for Doctoral Studies
Á undanförnum áratugum hafa fjölflúorsetin alkýlefni (PFAS) komið fram sem útbreidd mengunarefni, sem hafa greinst jafnvel á afskekktum svæðum á borð við Norðurskautið og Suðurskautslandið, með víðtæk áhrif á heilsu manna og vistkerfa. Sérstakar áhyggjur hafa vaknað vegna útbreiðslu PFAS og mögulegra áhrifa þeirra á lykillífverur í fæðuvefjum, svo sem kísilþörunga, sem eru stór hópur svifþörunga og gegna lykilhlutverki í lífefnafræðilegum hringrásum með því að standa undir um 20% af frumframleiðslu jarðar. Markmið þessarar ritgerðar var að rannsaka áhrif PFAS á tvær vistfræðilega ólíkar tegundir sjávarkísilþörunga, uppsjávartegundina Thalassiosira pseudonana og botnlægu tegundina Cylindrotheca closterium, og meta áhrif þeirra á lífeðlisfræði þörunganna, genatjáningu þeirra og á sambýlisörverur þeirra. Báðar tegundirnar voru ræktaðar í viðurvist langkeðja PFAS efnasambanda yfir styrkhallanda í skammtímatilraunum, auk langvarandi snertingar við PFASblöndu í styrk áþekkum þeim sem mælist í sjó á Norðurslóðum. Mældir voru lífeðlisfræðilegir þættir tengdir vexti, ljóstillífun, oxunarálagi og frumuefnasamsetningu. Þessar niðurstöður voru síðan samþættar greiningum á genatjáningu, markvissri efnaskiptagreiningu innan frumna (endometabolome) og breytingum á bakteríusamfélögum tengdum kísilþörungunum. Skammtímatilraunirnar sýndu marktæka vaxtarhömlun hjá báðum tegundum við háa (100 mg/L) og miðlungs (1 mg/L) PFAS-styrki, þar sem blöndur höfðu sterkari áhrif en einstök efni. Viðbrögðin voru þó tegundasértæk. C. closterium reyndist næmari fyrir perflúoraðri karboxýlsýrum (PFCAs; C8-C12), en T. pseudonana varð fyrir meiri áhrifum af PFAS-efnum með kolefniskeðjur lengri en C11. PFAS-útsetning dró úr ljóstillífunarvirkni, blaðgrænumagni og próteininnihaldi, en jók á sama tíma streituvísa eins og prólín og heildarvirkni andoxunarkerfa. Við langvarandi útsetningu fyrir PFAS-blöndu (0,9 ng/L) náðu vaxtarhraðar sér aftur á strik eftir 14 daga og urðu sambærilegir við samanburðarhópa, sem bendir til mögulegra aðlögunar- eða uppbótarviðbragða. Á sameindastigi sýndi T. pseudonana víðtæk áhrif PFAS á marga grunnefnaskiptaferla, en svörun C. closterium var markvissari og einkenndist einkum af aukinni virkni ABC-flutningspróteina og breytingum í miðlægum kolefnaefnaskiptum. Breytingar í efnaskiptum og genatjáningu hjá T. pseudonana bentu til tilfærslu frá vaxtarhvetjandi ástandi með mikla köfnunarefnisþörf yfir í streituaðlagaða svipgerð sem lagði meiri áherslu á viðhald oxunar-jafnvægis, viðgerð frumuhimna og myndun verndandi afleiddra efnasambanda fremur en áframhaldandi vöxt. PFAS-útsetning leiddi einnig til endurskipulagningar bakteríusamfélaga tengdra kísilþörungunum á hýsilháðan hátt, þó án verulegra breytinga á alfa-fjölbreytni, sem bendir til breytinga á samfélagsgerð frekar en hruns samfélaganna.
Synthesis, characterization and biological activity of the Cu (II)-1,3-PDTA [(Cu (II) (PDTA)] complex for the control of Erwinia chrysanthemi (soft rot) in the parsley manioc (Arracacia xanthorrhiza Bancroft)
(2025-01) de Almeida Teixeira, Cristiane Freitas; Carvalho, Claudio Teodoro; Zárate, Néstor Antonio Heredia; Fonseca, Gustavo Graciano; de Arruda, Eduardo Jose; Faculty of Natural Resource Sciences
Synthesis, characterization and biological activity of the Cu(II)-1,3-PDTA complex was performed by two synthetic routes: sodium and carbonate pathways. The Cu (II)-1,3-PDTA complex can be easily produced by the 1,3-PDTA binder, commercially available as Trilon F (BASF) which is available as sodium or acid salt for the coordination of Cu (II). The biological activity of the Cu (II)-1,3-PDTA [Cu (II)-PDTA] complex was performed to analyze the activity against the bacterium Erwinia chrysanthemi Bancroft. The bacterium is the causative agent of soft rot in the parsley maniac (Arracacia xanthorrhiza Bancroft). The bacterium was isolated from parsley manioc infected with soft rot. The metal complex sensitivity tests were performed by diffusion antibiogram. The mean values of the halos and standard deviations of the zones of inhibition were obtained for the [Cu (II) (PDTA)] and Streptomycin complexes. The concentrations of the complexes evaluated were 10-3, 10-2 and 10-1 M (equivalent to 36.3 g L-1 (3.63%), 3.63 g L-1 (0.363%) and 0.363 g L-1 (0.0363%), respectively). The halos were 25.0 ± 1.2 mm for control. For [Cu (II) (PDTA)] complexes, the obtained values were 9.5 ± 0.6, 15.0 ± 0.8 and 24.0 ± 0.8 via sodium and 12.0 ± 1.6, 25.0 ± 0.8 and 31.0 ± 1.9 via carbonate, for 10-3, 10-2 and 10-1 M, respectively. The results showed that the bactericidal activity of the Cu (II)-1,3-PDTA complex obtained by the two synthetic routes are adequate for the control of Erwinia chrysanthemi Bancroft.
Roles in brain stimulation, recording and interpreting neuroimaging data: a systematic survey of 26 countries on current practices in EEG, MRI, TCD, TMS and FUS
(2026-09-04) Valizada, Vugar; Sesseljuson, Leon Daði; Nardone, Raffaele; Thomschewski, Aljoscha; Trinka, Eugen; Holler, Yvonne; Centre for Doctoral Studies; Faculty of Psychology
Introduction: Clear role definitions in performing and interpreting neurophysiological and neuroimaging procedures are essential for patient safety and diagnostic accuracy. There is currently no comprehensive overview of the international landscape of health professionals responsible for these tasks. In the present review, we aimed to summarize local practices for electroencephalography (EEG), brain magnetic resonance imaging (MRI), transcranial magnetic stimulation (TMS), transcranial Doppler (TCD), and focused ultrasound stimulation (FUS).Methods: We systematically searched scientific literature, national health organizations websites, and contacted local health authorities from 26 countries.Results: EEG and brain MRI are typically performed by technicians and interpreted by physicians (neurologists or radiologists). TCD is performed and interpreted predominantly by physicians, since it requires real-time evaluation. Single-pulse TMS is either performed by physicians or requires the presence of physicians when the procedure is performed by a technician. The interpretation is done by physicians. Despite existing international recommendations, there is a significant absence of local guidelines for responsibilities in performing and interpreting TMS and FUS. In countries with information available, therapeutic use of rTMS, and FUS is performed by physicians (neurologists, psychiatrists, or surgeons).Discussion: The development of standardized national protocols is needed to ensure patients' safety and diagnostic accuracy in clinical settings for TMS and FUS.
Valorization of pulp and viscera from hybrid sorubim and pacu by production of protein concentrate using alkaline solubilization
(2025-03) Azambuja, Suéllen Patrícia Held; Nascimento, Kauyse Matos; Cortez-Vega, William Renzo; Cavenaghi-Altemio, Angela Dulce; Gelinski, Jane Mary Lafayette Neves; Fonseca, Gustavo Graciano; Faculty of Natural Resource Sciences
Fish protein concentration (FPC) by alkaline solubilization has proven to be an alternative method in adding value to muscle-based materials. The aim of this work was to evaluate the influence of different processes (decanting/sieving or centrifugation), reagents (sodium bicarbonate or sodium hydroxide) and washing cycles (1–4) on the quality of protein concentrates obtained from mechanically separated meat (MSM) and viscera of hybrid sorubim (Pseudoplatystoma reticulatum × P. corruscans) and pacu (Piaractus mesopotamicus) fishes. The protein concentrate was obtained by washing the viscera or MSM during up to four cycles (4:1 solution:meat ratio). In each cycle, the liquid waste and fat were removed by decanting/sieving or centrifugation. Moisture, crude protein, crude fat and crude ash contents were determined after each washing cycle. The moisture and protein contents increased immediately after the first washing up to 77.88% (dry basis). The lipid content decreased with the cycles down to 2.99% (dry basis). Higher FPC yield was obtained for MSM during the centrifugation process compared to the decantation/sieving process. Two weight yields above 100% were found in procedures with NaHCO3 and MSM of hybrid sorubim and pacu, probably due to the larger capacity of gel formation during protein concentration. Differences related to the fish species were more evident than the processes and utilized reagents.
Development and characterization of fish nuggets obtained from mechanically separated meat of spotted sorubim
(2026-01-22) Cavenaghi-Altemio, Angela Dulce; Fonseca, Gustavo Graciano; Faculty of Natural Resource Sciences
The fish industry has recently sought to diversify its product offerings to meet high consumer demand beyond just fresh fish. The use of mechanically separated fish meat (MSM) enables the production of various products, including breaded items. This study aimed to develop fish nuggets using MSM from spotted sorubim (Pseudoplatystoma corruscans) as the primary raw material, utilizing various formulations, and to evaluate the pH, shear force, microbiological safety, and sensory attributes of the developed products . The varying ingredients (4%) were bamboo fibre (F1 ), collagen fibre (F2 ), and textured soy protein (F3 ). The average pH of 6.5 showed no statistical difference between formulations (p > 0 .05), indicating that the varying ingredients did not affect this parameter. However, shear force varied significantly (p < 0.05), with the highest value of 8 .82 N observed for F3 . Sensory analysis revealed no significant differences (p > 0.05) between formulations for most attributes, except for taste, where F1 scored higher than F2 and F3 . The acceptance index was above 80% for all formulations . F1 showed the highest “certainly would purchase” response at 26.7%. Both F1 and F3 had a combined acceptance rate of 60% for “certainly and probably would purchase”, while F2 had a 50% acceptance rate. The results suggest that taste plays a crucial role in the sensory acceptance of the nuggets, with bamboo fibre positively enhancing flavour.
How different life-history strategies respond to changing environments : A multi-decadal study of groundfish communities
(2025-12) Sólmundsson, Jón; Sigurðsson, Ólafur; Jónsdóttir, Ingibjörg G.; Jónsson, Steingrímur; Faculty of Natural Resource Sciences
In recent decades, climate variability has led to significant shifts in the distribution and prevalence of various fish species in the North Atlantic. These changes are well documented for several groundfish species within the zoogeographical transition waters surrounding Iceland, coinciding with variations in seawater temperature. This study analyses groundfish assemblage structure through the frameworks of life-history theory and biogeography. Utilizing annual bottom trawl survey data from 1987 to 2024, groundfish species in the continental shelf waters around Iceland were categorized into three primary life-history strategies: periodic, opportunistic, and equilibrium, based on their life-history traits. Over the study period, these strategies demonstrated distinct responses to environmental changes, influenced by the biogeography of the species. Increased water temperatures were accompanied by an influx of Atlantic and Boreal species, while species richness for Arctic fish remained similar or decreased. Boreal periodic species emerged as the most prominent in Icelandic waters, maintaining long-term stability in abundance and distribution. However, environmental conditions in recent decades have favoured southerly warmer-water (Atlantic) species across life-history strategies, while most Arctic species have experienced declining abundance trends. Opportunistic strategists exhibited the most pronounced temporal changes during the warming period.
Effect of bitter orange or sweet orange juices on the characteristics of beef sausages
(2025) Cavenaghi-Altemio, Angela D.; Martins, Nathalia B.C.; Fonseca, Gustavo G.; Faculty of Natural Resource Sciences
This study evaluated the effects of replacing water with bitter orange and pear orange juices on the properties of beef sausages. Three formulations were prepared: control with water (F1) and two experimental formulations with bitter orange juice (F2) and pear orange juice (F3). Moisture, protein, lipid, ash, carbohydrate content, pH, water activity, shear force, and instrumental color were analyzed. Formulations complied with legislation for moisture (< 70 %), protein (> 12 %), and lipid (< 30 %) content. Moisture content ranged from 55.96 % (F3) to 60.32 % (F1), with the reduction in F2 and F3 attributed to the soluble solids in the juices. Protein content remained stable across formulations (22.24–23.39 %), reflecting the consistent meat proportion. Lipid content varied significantly, with F1 (15.25 %) showing the lowest value and F3 (19.29 %) the highest due to altered lipid retention influenced by acid-matrix interactions. F2 exhibited the highest acidity (0.40 g 100 mL–¹) and the lowest pH (4.68), leading to the lowest shear force (56.68 N). Due to particularities in the preparation, meat and fat portions were analyzed for colorimetry. Lighter sausages with lower redness (a*) values in F2 (5.20) and F3 (4.48) compared to F1 (8.50), and higher yellowness (b*) in F2 (7.26) were observed for the meat portion. The total color difference (ΔE*) values indicated noticeable differences, particularly for F2 and F3 in the meat portion and F3 in the fat portion. These findings demonstrated that orange juices can modify the properties of beef sausages, enhancing their functional attributes, offering opportunities for the development of new food products.
“Outcomes of treatment for people with type 2 diabetes within two nurse-led clinics in primary care in Iceland”
(2025) Birgisdóttir, Matthildur; Skúladóttir, Hafdís; Sigurðardóttir, Árún Kristín; Faculty of Nursing
As the prevalence of type 2 diabetes increases in Iceland, more nurse-led diabetes clinics have been established in primary health. This study aimed to evaluate treatment outcomes in patients with type 2 diabetes at two rural nurse-led diabetes clinics and compare these outcomes with guidelines. A retrospective cohort study was conducted in primary care settings in Northern Iceland using secondary data from medical recording systems. The sample (n = 88) included patients with two glycated haemoglobin (HbA1c) measurements taken at least 6 months apart (Time 1 and 2). Between Time 1 and 2, HbA1c levels (p = 0.049), body mass index (p = 0.013), and systolic blood pressure (p = 0.040) decreased. At time 2, approximately 70% of patients reached clinical goals for HbA1c levels, 33% for body mass index, 56% for systolic blood pressure, and 49% for diastolic blood pressure. This finding is consistent with those of other European studies in diabetes care. Assessing healthcare outcomes is beneficial for small rural clinics, where work is often conducted in isolation. This programme evaluation study conducted in two nurse-led clinics in Iceland demonstrated improved diabetes outcomes with care aligned with clinical guidelines and provided a baseline for measuring future outcomes.
Applying the guided self-determination counselling method in primary healthcare among people at risk of developing type 2 diabetes : A qualitative study
(2025-11) Kolltveit, Beate Christin Hope; Arnardóttir, Elín; Oftedal, Bjørg Frøysland; Sigurðardóttir, Árún Kristín; Faculty of Nursing
Aim: To explore how nurses experienced using the Guided Self-Determination (GSD) counselling method in primary healthcare for the follow-up of patients at risk of developing type 2 diabetes. Design: This study had a qualitative design. Methods: We used individual interviews with nurses in Norway (n = 5) and Iceland (n = 6) to collect data. The nurses had prior to this qualitative study participated in a randomised controlled trial, by applying the GSD counselling method in primary healthcare. The data was analysed by using qualitative content analysis. Results: The findings in this study resulted in the identification of three categories: (1) Promoting change in patient awareness and motivation, (2) Facilitation of health behaviour change, and (3) Challenges in applying the GSD method in patient consultations. The counselling method assisted the nurses to approach patients in a different way and to ask questions that stimulated personal reflection and increased the patients´ health awareness. Patient or Public Contribution: Patient representatives contributed in discussing the relevance of the study objectives and justification for undertaking the research, and in the development of adequate written patient information for the study.

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