Icelandic Population Research Articles

Holocene deglaciation drove rapid genetic diversification of Atlantic walrus.

Rapid global warming is severely impacting Arctic ecosystems and is predicted to transform the abundance, distribution and genetic diversity of Arctic species, though these linkages are poorly understood. We address this gap in knowledge using palaeogenomics to examine how earlier periods of global warming influenced the genetic diversity of Atlantic walrus (Odobenus rosmarus rosmarus), a species closely associated with sea ice and shallow-water habitats. We analysed 82 ancient and historical Atlantic walrus mitochondrial genomes (mitogenomes), including now-extinct populations in Iceland and the Canadian Maritimes, to reconstruct the Atlantic walrus' response to Arctic deglaciation. Our results demonstrate that the phylogeography and genetic diversity of Atlantic walrus populations was initially shaped by the last glacial maximum (LGM), surviving in distinct glacial refugia, and subsequently expanding rapidly in multiple migration waves during the late Pleistocene and early Holocene. The timing of diversification and establishment of distinct populations corresponds closely with the chronology of the glacial retreat, pointing to a strong link between walrus phylogeography and sea ice. Our results indicate that accelerated ice loss in the modern Arctic may trigger further dispersal events, likely increasing the connectivity of northern stocks while isolating more southerly stocks putatively caught in small pockets of suitable habitat.

Biomarkers of the L-Arginine/Dimethylarginine/Nitric Oxide Pathway in People with Chronic Airflow Obstruction and Obstructive Sleep Apnoea.

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA) are common chronic diseases that are associated with chronic and intermittent hypoxemia, respectively. Patients affected by the overlap of COPD and OSA have a particularly unfavourable prognosis. The L-arginine/nitric oxide (NO) pathway plays an important role in regulating pulmonary vascular function. Asymmetric (ADMA) and symmetric dimethylarginine (SDMA) interfere with NO production. We analysed the serum concentrations of ADMA, SDMA, L-arginine, L-citrulline, and L-ornithine in a large sample of the Icelandic general population together with chronic airflow obstruction (CAO), a key physiological marker of COPD that was assessed by post-bronchodilator spirometry (FEV1/FVC < LLN). OSA risk was determined by the multivariable apnoea prediction (MAP) index. 713 individuals were analysed, of whom 78 (10.9%) showed CAO and 215 (30%) had MAP > 0.5. SDMA was significantly higher in individuals with CAO (0.518 [0.461-0.616] vs. 0.494 [0.441-0.565] µmol/L; p = 0.005), but ADMA was not. However, ADMA was significantly associated with decreasing FEV1 percent predicted among those with CAO (p = 0.002). ADMA was 0.50 (0.44-0.56) µmol/L in MAP ≤ 0.5 versus 0.52 (0.46-0.58) µmol/L in MAP > 0.5 (p = 0.008). SDMA was 0.49 (0.44-0.56) µmol/L versus 0.51 (0.46-0.60) µmol/L, respectively (p = 0.004). The highest values for ADMA and SDMA were observed in individuals with overlap of CAO and MAP > 0.5, which was accompanied by lower L-citrulline levels. The plasma concentrations of ADMA and SDMA are elevated in COPD patients with concomitant intermittent hypoxaemia. This may account for impaired pulmonary NO production, enhanced pulmonary vasoconstriction, and disease progression.

Modeling recombination rate as a quantitative trait reveals new insight into selection in humans.

Meiotic recombination is both a fundamental biological process required for proper chromosomal segregation during meiosis and an important genomic parameter that shapes major features of the genomic landscape. However, despite the central importance of this phenotype, we lack a clear understanding of the selective pressures that shape its variation in natural populations, including humans. While there is strong evidence of fitness costs of low rates of recombination, the possible fitness costs of high rates of recombination are less defined. To determine whether a single lower fitness bound can explain the variation in recombination rate observed in human populations, we simulated the evolution of recombination rate as a sexually dimorphic quantitative trait. Under each scenario, we statistically compared the resulting trait distribution to the observed distribution of recombination rates from a published study of the Icelandic population. To capture the genetic architecture of recombination rate in humans, we modeled it as a moderately complex trait with modest heritability. For our fitness function, we implemented a hyperbolic tangent curve with several flexible parameters to capture a wide range of existing hypotheses. We found that costs of low rates of recombination alone are likely insufficient to explain current variation in recombination rate in both males and females, supporting the existence of fitness costs of high rates of recombination in humans. With simulations using both upper and lower fitness boundaries, we describe a parameter space for the costs of high recombination rate that produces results consistent with empirical observations.

A population-based cohort study on changes in breast, lung and colorectal cancer incidence and mortality among non-Western immigrant women

BackgroundCancer risk varies geographically, and migrants are influenced by different risk factors before, during and after migration. Increased migration from non-Western countries to the Nordic countries calls for a better understanding of the migrants’ cancer risk and the change in risk patterns over time. The aim of this study was to compare the incidence and mortality of breast, colorectal and lung cancer between non-Western immigrant and the native female population in Denmark, Finland, Iceland, and Norway.Material and methodsData from national registries were processed and pre-analysed in each country. Multivariate Poisson regression models were used to model the relative differences in incidence and mortality as rate ratios (RR). The country-specific estimates and summary statistics were pooled together using a random effects model.ResultsNon-Western immigrant women had significantly lower breast (RR 0.71, 0.65–0.78), colorectal (RR 0.72, 0.57–0.92) and lung (RR 0.55, 0.42–0.72) cancer incidence rates than native women, and the risk of these cancers among immigrant women increased with duration of residence. Differences were parallel in breast, colorectal and lung cancer mortality (RR 0.64, 0.55–0.74; RR 0.66, 0.48–0.92; RR 0.51, 0.34–0.79). Among immigrant women, higher education increased the risk for breast cancer and decreased it for lung cancer.ConclusionThe results significantly complement and add to the previous findings of cancer burden and cancer burden transition among migrants and provide evidence of a prolonged cancer risk advantage among non-Western immigrant women. However, the findings show an increasing risk of lifestyle-related cancers with increasing duration of residence in the host country. Further studies are needed to discover underlying reasons for this phenomenon.

Prevalence of Taylorella equigenitalis in an Icelandic horse population

Contagious Equine Metritis (CEM) is an infectious disease caused by Taylorella equigenitalis (TEq). In mares, clinical as well as subclinical infections have the potential to cause short-term infertility. Stallions are generally believed to be asymptomatic carrier of TEq. Transmission commonly occurs venereally and therefore poses a risk for horses in less controlled natural mating programs (Timoney, Comp. Immun. Microbiol. Infect. Dis. 1996, 3: 199-204). In the Icelandic breed, pasture breeding is routinely performed. Therefore, the aim of this study was to investigate the prevalence of TEq in intact stallions, mares and geldings of the Icelandic breed. We hypothesized that there is a high prevalence of TEq in Icelandic horses independent of their breeding purpose. In total, 437 Icelandic horses from 16 randomly selected farms in southern Germany and Austria were examined. In a first trial, 76 intact Icelandic males from 10 farms were compared to a reference group (n=86) consisting of 35 Haflinger and 51 Draft intact male horses from 31 farms. Breeds of the reference group are also known to be used in natural mating programs. In a second trial, 105 geldings and 256 mares from 11 farms were tested for presence of TEq. In both trials, swabs from standardized localizations of the male (penis) or female (clitoris) genital tract were collected (WOAH for TEq). The presence of TEq DNA was determined using quantitativePCR. There was a significant higher prevalence of TEq-positive samples in Icelandic intact males (n=23) compared to the reference group (n=4; p=0.0001). Both groups were further differentiated regarding their actual use for breeding. Pairwise comparison of both groups resulted in a significantly lower number of TEq-positive intact males used for breeding compared to the horses without breeding (reference group: p=0.019; Icelandic group: p=0.006). In the second trial, a higher prevalence of TEq-positive geldings compared to mares (36.2% and 5.5%, respectively) was detected. Mares were further differentiated in mares with breeding history (n=134) and mares without (n=122). A higher prevalence in mares without breeding history could be found (2.2% and 9.0%, respectively). The hypothesis could be confirmed that in the Icelandic breed a higher prevalence of TEq-positive stallions compared to stallions also used in natural mating programs exists. Furthermore, TEq has a higher prevalence in geldings compared to mares of Icelandic horses. Therefore, geldings might represent a reservoir of TEq in this breed. The spread of CEM is of economic importance and should be considered even in horses never used for breeding. Further studies investigating the genotype of the CEM strains in the Icelandic breed might help to understand further ways of transmission.

DRUG-INDUCED AUTOIMMUNE HEPATITIS: SYSTEMATIC REVIEW AND CASE STUDY

Drug-induced liver injury (DILI) is one of the types of adverse reactions to drugs that occur as a result of their hepatotoxic effect. The pathogenesis of drug-induced autoimmune hepatitis (LIAH) is based on the production of autoantibodies to neoantigens, which are proteins of the cytochrome P450 system, which are the result of the reaction of drug metabolites. A clinically relevant problem, such as drug-induced liver damage, affects 1-1.5 million patients almost every year. The annual incidence of DILI ranges from 2.3-13.9 per 100,000 population in population studies from Europe. The Icelandic population study recorded the highest rates of 19.1 per 100,000 population per year. And in the only study based on the US population, it was found that DILI is approximately 3 per 100,000 population. Acute hepatitis is currently a well-known manifestation, and accounts for more than 90% of liver damage caused by medications. According to studies, 2.9 - 8.8% of DILI and 2 - 18% of AIH are associated with drug-induced autoimmune hepatitis. The incidence of drug-induced liver damage with the presence of antibodies (antibodies to nuclear antigen, smooth muscle and soluble liver antigen) to AIH is 83% for nitrofurantoin, 74% for minocycline, 60% for methyldopa and 43% for hydralazine.

Cystic echinococcosis in Iceland: a brief history and genetic analysis of a 46-year-old Echinococcus isolate collected prior to the eradication of this zoonotic disease.

Cystic echinococcosis (CE) is considered the most severe parasitic disease that ever affected the human population in Iceland. Before the start of eradication campaign in the 1860s, Iceland was a country with very high prevalence of human CE, with approximately every fifth person infected. Eradication of CE from Iceland by 1979 was a huge success story and served as a leading example for other countries on how to combat such a severe One Health problem. However, there is no genetic information on Echinococcus parasites before eradication. Here, we reveal the genetic identity for one of the last Echinococcus isolates in Iceland, obtained from a sheep 46 years ago (1977). We sequenced a large portion of the mitochondrial genome (8141 bp) and identified the isolate as Echinococcus granulosus sensu stricto genotype G1. As G1 is known to be highly infective genotype to humans, it may partly explain why such a large proportion of human population in Iceland was infected at a time . The study demonstrates that decades-old samples hold significant potential to uncover genetic identities of parasites in the past.

Habitat preference of common minke whale (Balaenoptera acutorostrata) in Skjálfandi Bay, Iceland

Anthropogenic activity has contributed to increased extinction rates, creating a need to monitor and conserve vulnerable species. Understanding the distribution and habitat preference of threatened species can identify crucial habitats, for which protection can improve the population size numbers. Here, we investigate the habitat preference of the common minke whale, a rapidly declining yet understudied cetacean species. We analysed minke whale sightings over time and in relation to environmental factors (depth, sea surface temperature, sediment, chlorophyll), based on long-term monitoring data from Skjálfandi Bay in the northeast of Iceland. We found minke whales have a preference for water depth between 9-70m, and water temperature of either colder than 6°C or warmer than 9°C. Shallow depth was a strong predictor of minke whale presence, which matched sandeel distribution. Sandeels require shallow depths for spawning and overwinter burrowing, and the match between minke whale depth presence and sandeel habitat is in good agreement with sandeels being an important minke whale food source. Although the relationship between minke whale presence and sea surface temperature is weak, it also matched sandeel distribution. We also detected a decline in minke whale population size over the study period (2009-2018). The population decline observed here is consistent with the population trend estimated for the Icelandic population. We suggest that the habitat preferences identified here should be considered for conservation recommendations and minimising disturbance in the identified, crucial feeding areas.

Mortality of multiple sclerosis in Iceland population-based mortality of MS in incidence and prevalence cohorts.

Mortality is an important feature of the natural history of multiple sclerosis (MS). We report the mortality of all individuals with MS in Iceland, identified in a nationwide population-based study. The results are based on a prevalence cohort and an incidence cohort. The prevalence cohort consisted of all patients with MS (n = 526) living in Iceland on the 31 December 2007. The incidence cohort consisted of all residents of Iceland (n = 222) diagnosed with MS during 2002 to 2007. Mortality was determined by following both the incidence cohort (from diagnosis) and the prevalence cohort (from the prevalence day) until death or 31 December 2020. The mortality, associated with MS, was compared with that expected in the Icelandic population (standardized mortality ratio (SMR)). (a) Prevalence cohort (n = 526). The mean follow up was 12.0 years (range 0.3-13.0). The SMR was 1.6 (95% confidence interval (CI) 1.3-2.0). (b) Incidence cohort (n = 222). The mean follow up was 15.4 years (range 3.7-18.5). The SMR was 1.2 (95% CI 0.6-2.2). During the follow-up period, there was a substantial increase in mortality among the patients with MS, compared with the general population. There was no increase in mortality among the incidence cohort, when followed for up to 18.5 years following diagnosis.

Kumlbúa þáttr, an Eschatological Event: The Traumatic Ontology of Being in Time in Medieval Iceland

<i>Kumlbúa þáttr</i>, an Eschatological Event: The Traumatic Ontology of Being in Time in Medieval Iceland

Productive language development in classroom activities in Poland and Iceland: The diversity of language context in the digital world

The aim of the study was to gain insight into Polish and Icelandic teachers’ attitudes towards children’s productive language skills in the societal languages, Polish and Icelandic, their teaching practices in fostering these skills, and to identify any obstacles experienced. The study is based on semi-structured interviews with two teachers in each country. The Icelandic population is only 364.000, while the number in Poland is 39.857.000. In Iceland, English is an additional language to Icelandic, whereas Polish is the dominant language in Poland. Reading literacy among Icelandic youth on PISA has declined and Polish adolescents have improved. According to the Icelandic teachers, the diversity of language context in Iceland has a negative effect on children‘s Icelandic language skills. Speaking and writing appeared to be practised in a more elaborate way by the Icelandic teachers. School activities focused on speaking and writing can be improved in both the Polish and the Icelandic classes./ Keywords: primary school, literacy, oral skills, discussions, writing instruction, classroom practices

Four missense genetic variants in CUBN are associated with higher levels of eGFR in non-diabetes but not in diabetes mellitus or its subtypes: A genetic association study in Europeans.

Rare genetic variants in the CUBN gene encoding the main albumin-transporter in the proximal tubule of the kidneys have previously been associated with microalbuminuria and higher urine albumin levels, also in diabetes. Sequencing studies in isolated proteinuria suggest that these variants might not affect kidney function, despite proteinuria. However, the relation of these CUBN missense variants to the estimated glomerular filtration rate (eGFR) is largely unexplored. We hereby broadly examine the associations between four CUBN missense variants and eGFRcreatinine in Europeans with Type 1 (T1D) and Type 2 Diabetes (T2D). Furthermore, we sought to deepen our understanding of these variants in a range of single- and aggregate- variant analyses of other kidney-related traits in individuals with and without diabetes mellitus. We carried out a genetic association-based linear regression analysis between four CUBN missense variants (rs141640975, rs144360241, rs45551835, rs1801239) and eGFRcreatinine (ml/min/1.73 m2, CKD-EPIcreatinine(2012), natural log-transformed) in populations with T1D (n ~ 3,588) or T2D (n ~ 31,155) from multiple European studies and in individuals without diabetes from UK Biobank (UKBB, n ~ 370,061) with replication in deCODE (n = 127,090). Summary results of the diabetes-group were meta-analyzed using the fixed-effect inverse-variance method. Albeit we did not observe associations between eGFRcreatinine and CUBN in the diabetes-group, we found significant positive associations between the minor alleles of all four variants and eGFRcreatinine in the UKBB individuals without diabetes with rs141640975 being the strongest (Effect=0.02, PeGFR_creatinine=2.2 × 10-9). We replicated the findings for rs141640975 in the Icelandic non-diabetes population (Effect=0.026, PeGFR_creatinine=7.7 × 10-4). For rs141640975, the eGFRcreatinine-association showed significant interaction with albuminuria levels (normo-, micro-, and macroalbuminuria; p = 0.03). An aggregated genetic risk score (GRS) was associated with higher urine albumin levels and eGFRcreatinine. The rs141640975 variant was also associated with higher levels of eGFRcreatinine-cystatin C (ml/min/1.73 m2, CKD-EPI2021, natural log-transformed) and lower circulating cystatin C levels. The positive associations between the four CUBN missense variants and eGFR in a large population without diabetes suggests a pleiotropic role of CUBN as a novel eGFR-locus in addition to it being a known albuminuria-locus. Additional associations with diverse renal function measures (lower cystatin C and higher eGFRcreatinine-cystatin C levels) and a CUBN-focused GRS further suggests an important role of CUBN in the future personalization of chronic kidney disease management in people without diabetes.

Tetracapsuloides bryosalmonae and proliferative kidney disease in Icelandic salmonids – Comparative data from two different time periods

Tetracapsuloides bryosalmonae is a myxozoan parasite and the causative agent of proliferative kidney disease (PKD), a serious, temperature-dependent and emerging disease affecting salmonid fish. It was first identified in Iceland in 2008, from Arctic charr inhabiting a shallow lowland lake. The aim of this study was to investigate the distribution and prevalence of macroscopic and subclinical T. bryosalmonae infections in Icelandic salmonids and compare different time periods, in context with depths, volumes, altitudes and areas of the lakes and fish age. Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) from 34 lakes, sampled between 1994–1998 and 2009–2017, were examined for macroscopic signs of PKD (n = 2,151) and the presence of T. bryosalmonae infections (n = 1,424). In the earlier period, 43% of lakes (10/23) harboured T. bryosalmonae -infected fish. The mean prevalence in those lakes was 62.1%, being most common in shallow lowland lakes whilst deeper lakes at high altitudes were all free from infection. Only a single fish from one lake showed macroscopic signs of PKD, a shallow lowland lake in southwestern Iceland. In the latter period, T. bryosalmonae was found in 16/18 lakes studied (89%), with a mean prevalence of 78–79% (excluding T.b. free lakes), being most common in the smaller, shallower lakes at lower alttudes. Macroscopic signs of PKD were observed in 11 of 18 of the lakes studied (61%) with prevalences up to 67%, most common in younger fish inhabiting small shallow lowland lakes. The results indicate that the distribution of T. bryosalmonae and the presence of PKD in Iceland have increased over the last few decades. The disease was almost non-existent in the 1990s but has become very common during the last decade or two. With further water temperature increases, as predicted by climate models, PKD is likely to increasingly affect wild salmonid populations in Iceland.

Association of eGFR and mortality with use of a joint model: results of a nationwide study in Iceland.

Prior studies on the association of estimated glomerular filtration rate (eGFR) and mortality have failed to include methods to account for repeated eGFR determinations. The aim of this study was to estimate the association between eGFR and mortality in the general population in Iceland employing a joint model. We obtained all serum creatinine and urine protein measurements from all clinical laboratories in Iceland in the years 2008-16. Clinical data were obtained from nationwide electronic medical records. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation and categorized as follows: 0-29, 30-44, 45-59, 60-74, 75-89, 90-104 and >104mL/min/1.73 m2. A multiple imputation method was used to account for missing urine protein data. A joint model was used to assess risk of all-cause mortality. We obtained 2 120 147 creatinine values for 218 437 individuals, of whom 84 364 (39%) had proteinuria measurements available. Median age was 46 (range 18-106) years and 47% were men. Proteinuria associated with increased risk of death for all eGFR categories in persons of all ages. In persons ≤65years, the lowest risk was observed for eGFR of 75-89mL/min/1.73 m2 without proteinuria. For persons aged >65years, the lowest risk was observed for eGFR of 60-74mL/min/1.73 m2 without proteinuria. eGFR of 45-59mL/min/1.73 m2 without proteinuria did not associate with increased mortality risk in this age group. eGFR >104mL/min/1.73 m2 associated with increased mortality. These results lend further support to the use of age-adapted eGFR thresholds for defining chronic kidney disease. Very high eGFR needs to be studied in more detail with regard to mortality.

Adult chronic pain in relation to psychological trauma in childhood

Chronic pain is a health problem that is one of leading cause of disability. Studies have shown that various aspects of a person's history, such as difficult experiences in early life, can affect lifestyle and health later. The aim of this study was to examine the relationship between chronic pain, adverse childhood experience (ACE) and violence in adulthood in the general population of Iceland. MATERIAL AND METHODS: A retrospective cross-sectional study. The sample was 12.400 individuals, 18-80 years of age, randomly selected from respondents' group of the data collection company MASKINA (National Portal). Data on chronic pain, ACE and experience of violence in adulthood were examined. Statistical processing was carried out in IBM SPSS Statistics 28th edition. RESULTS: Response rate was 44.8% (female 57.1%, M=56 years). Prevalence of chronic pain (≥3 months) was 40.1%. A total of 91.1% of participants answered questions about ACE, of which 16.1% ≥4 ACE-scores. There was a positive relationship between ACE and chronic pain (OR = 1.675, 95% CI: 1.420 - 1.977). Those who had ≥4 ACE-scores were more likely to have experienced violence in adulthood. CSONCLUSION: The results of this study show that chronic pain and violence in adulthood can be associated with psychological childhood trauma. People who experience psychological childhood trauma and violence in adulthood are more likely to suffer from chronic pain. It is important to be aware of experiences of childhood psychological trauma and violence when people seek healthcare for chronic pain.

Prevalence of smoldering multiple myeloma based on nationwide screening.

Smoldering multiple myeloma (SMM) is an asymptomatic precursor to multiple myeloma. Here we define the epidemiological characteristics of SMM in the general population in Iceland. The iStopMM study (ClinicalTrials.gov ID: NCT03327597 ) is a nationwide screening study for multiple myeloma precursors where all residents in Iceland 40 years or older were invited to participate. SMM was defined as 10-60% bone marrow plasma cells and/or monoclonal (M) protein concentration ≥3 g dl-1, in the absence of myeloma-defining events. Of the 80,759 who gave informed consent to participate, 75,422 (93%) were screened. The prevalence of SMM in the total population was 0.53% (95% confidence interval (CI) = 0.49-0.57%) in individuals 40 years or older. In men and women, the prevalence of SMM was 0.67% (95% CI = 0.62-0.73%) and 0.39% (95% CI = 0.35-0.43%), respectively; it increased with age in both sexes. For the 193 individuals with SMM, median age was 70 years (range 44-92 years) and 60% were males. The mean M protein concentration of individuals with SMM was 0.62 g dl-1 (range 0.01-3.5 g dl-1) and 73% had 11-20% bone marrow plasma cell infiltration. The high prevalence of SMM has implications for future treatment policies in multiple myeloma as the evidence supporting treatment initiation at the SMM stage is emerging.

Metachronous colorectal cancers in Icelandic MSH6 and PMS2 Lynch syndrome carriers in 1955-2017: A population-based study.

76 Background: The prevalence of Lynch syndrome in Iceland is the highest described so far or 1:226 with three founder mutations, one in MSH6 and two in PMS2, and was first reported in 2017. Lynch syndrome predisposes carriers to colorectal cancer and metachronous primaries. Most data on metachronous colorectal cancer reflects on MLH1 and MSH2 carriers and is not well described in MSH6 and PMS2 carriers. The purpose of this study was to examine the cumulative incidence of metachronous colorectal cancer in Icelandic Lynch syndrome carriers diagnosed with colorectal cancer from 1955-2017. Methods: This retrospective study included all individuals with pathogenic variants in mismatch repair genes identified in a nationwide genotype database and a colorectal cancer diagnosis in the Icelandic Cancer Registry from 1955-2017. DeCODE genetics has collected extensive genotypic information on the Icelandic population sequencing the whole genomes of 49,708 Icelanders and imputing genotypes into 116,573 Icelanders whose DNA had been genotyped with SNP chips. Cancer information was obtained from patient charts and cause of death obtained from the Cause of Death Register. All polyp pathology was accessed in the pathology registry and reassessed by two pathologists. Results: A total of 65 individuals developed colorectal cancer during the study period with 34 (52.3%) PMS2 carriers and 25 (38.5%) MSH6 carriers. The cumulative incidence of metachronous colorectal cancer was low or one case (1.5%) in an MSH2 carrier with a median follow-up time of 58 months (Q1 8.0, Q3 167.0, range 0-365 months) in the cohort. Only two (3.1%) individuals, one with MSH2 and one with MSH6 pathogenic variants, underwent a total colectomy. Median age at first colorectal cancer diagnosis was 63 years (Q1 54.0, Q3 72.5, range 28-94). Thirty-one (47.7%) individuals had polyps resected during the study period with adenomas (67.1%) being the most common. Significantly more MSH6 carriers had a history of advanced adenomas as compared to PMS2 carriers (36.0 % vs 11.8%, p = 0.026). Five-year colorectal cancer survival was 81.4% for PMS2 carriers and 71.5% for MSH6 carriers. Conclusions: The incidence of metachronous colorectal cancer was zero in Lynch syndrome carriers with MSH6 or PMS2 pathogenic variants from 1955-2017 despite these individuals not undergoing rigorous Lynch syndrome screening. This would support performing segmental colectomies and following European screening guidelines for MSH6 and PMS2 carriers in Iceland.

Possible causes of amphi-Atlantic distribution of Orchestia gammarellus (Pallas, 1776) (Crustacea, Amphipoda, Talitridae) in the North Atlantic: a review

Hypotheses concerning the modern distribution of Orchestia gammarellus (Crustacea, Amphipoda, Talitridae) and its causes in the North Atlantic are discussed. The synanthropic dispersal hypothesis of Henzler and Ingólfsson (2008) considers O. gammarellus as originating on the eastern shore of the North Atlantic and being transported by humans to Iceland and the western Atlantic shore (Newfoundland and the Maritime Provinces of Canada). The Eocene and natural dispersal hypothesis of Myers and Lowry (2020) proposes a geologically earlier origin of O. gammarellus when the west and east shores of the North Atlantic were still connected. Present day amphi-Atlantic distribution was explained by vicariance, with the vicariant event causing separation of O. gammarellus being continental drift drawing apart the west and east shores of the North Atlantic. A post-glacial natural dispersal hypothesis proposed herein, involves transport on ice floes or in driftwood from European shores to Iceland and the Atlantic Provinces of Canada. The small genetic distances amongst populations found by Henzler and Ingólfsson (2008) at the COI gene are inconsistent with the Eocene vicariance hypothesis. On evolutionary grounds, we question Myers and Lowry’s (2020) designation of the Icelandic and Canadian populations as a new species of Orchestia. Existing molecular and morphological data are insufficient to distinguish between human-aided dispersal and natural rafting.

Flames of Time:

The manuscript as narrator in Icelandic children’s novel Bál tímans (2022) belongs to a literary tradition of sentient object narrators who document the domestic spaces in which they circulate. Bál tímans shifts the reader’s focus to normally invisible manuscript owners and users, including women and children, bringing attention to disparities in access created through archive-building activities. In domestic settings, Möðruvallabók is accessible to a broad segment of the Icelandic population through practices of social reading, women’s book ownership, and home education. In the archive, human-manuscript interactions are restricted to a narrow and initially male-only elite. While tensions between preservation and access are resolved when the codex is exhibited in a museum space where it can share its stories with a wider audience, Bál tímans examines what can be lost by bringing cultural objects into archival spaces.

Recent spread of non-indigenous ascidians (Chordata: Tunicata) in Icelandic harbours

ABSTRACT Global shipping facilitates the introduction of fouling organisms to new geographic areas. The increase in maritime transport in recent decades has led to unprecedented development, where marine coastal waters have become one of the most invaded habitats around the globe. Among the most successful invaders are ascidians. Despite the geographic and oceanographic isolation of Iceland, it is far from being excluded as a recipient region. Ascidians have successfully been able to establish stable populations in Iceland that are slowly expanding around the SW region. Here we report the first record of Ascidiella scabra in Icelandic waters, and the spread of seven non-indigenous ascidians across the S-SW Icelandic harbours. We compare their relative abundances to our survey from 2018. The bulk of these ascidians is not only present in the temperate Atlantic Ocean, but also in the Northwest Pacific and temperate Australasia, revealing that global homogenization of the ascidiofauna is emerging in anthropized coastal areas. The rising of sea surface temperature, driven by climate change, is likely to continue to support the development of this scenario leading to biodiversity loss, which could endanger living resources with severe economic impacts. Highlights Non-indigenous ascidians are spreading across the Icelandic harbours. Ascidiella scabra has arrived to Iceland. Global homogenization of coastal zones is emerging. Climate change will support the development of this scenario.