Sea Ice, Climate, and Icelandic Fisheries in the Eighteenth and Nineteenth Centuries

The expansion and subsequent decline in catches in many fisheries of the world during the 20th century suggest that the history of fisheries needs our urgent attention. Analysis of environmental effects on fisheries in the past (when overfishing was not an issue) may cast light on current concerns about declining fish stocks. Primary documentary evidence from Iceland was used for preliminary investigations into correlations between sea-ice extent, sea temperatures, ocean currents, and cod fishing, and hence between severe weather and the decline of Icelandic fisheries in the past. The sources suggest that fishing was generally successful in Iceland during the medieval period and well into the 16th century. However, in the 17th through the 19th centuries, the fisheries failed on numerous occasions, sometimes for several years. The causes of these failures were complex. Climate likely played a part, and this was certainly the perception of contemporary writers; however, socioeconomic factors were also involved. L'expansion, et le déclin qui suivit, touchant les prises de nombreuses pêcheries dans le monde au cours du XXe siècle suggèrent que nous devons nous pencher sans tarder sur l'historique de la pêche. Une analyse des répercussions environnementales sur les pêcheries dans le passé (quand la surpêche ne constituait pas un problème) peut jeter de la lumière sur les enjeux actuels concernant l'épuisement des stocks de poissons. Des preuves documentaires primaires provenant d'Islande ont servi aux recherches préliminaires portant sur les corrélations entre l'étendue de la glace marine, les températures de la mer, les courants océaniques et la pêche de la morue - donc entre le mauvais temps et le déclin des pêcheries islandaises dans le passé. Les sources suggèrent que la pêche était généralement fructueuse en Islande durant la période médiévale et les premières décennies du XVIe siècle. Toutefois, du XVIIe à la fin du XIXe siècle, les pêcheries connurent bien des échecs, parfois sur plusieurs années. Les causes en étaient complexes. Si le climat jouait vraisemblablement un rôle - ce que perçurent bien les écrivains de l'époque -, des facteurs socio-économiques entraient aussi en jeu.

No correlation between rates of caesarean section and perinatal mortality in Iceland

Hægt er að lesa greinina í heild sinni með því að smella á hlekkinn View/OpenINTRODUCTION: Caesarean section rates have increased over the past decades without a concomitant decrease in perinatal mortality. In Iceland the same trend has been seen while at the same time perinatal mortality rate has remained low. Most caesarean sections are done at term. Crude perinatal mortality rates give limited information about whether the increase in section rates leads to a lower perinatal death rate among term non-malformed singleton infants. The relation between caesarean section and perinatal mortality rates in singleton, non-malformed infants of birthweight > or =2500 g in Iceland during 1989-2003 was studied. MATERIALS AND METHODS: Information about gestational length, birthweight, parity, onset of labour and previous caesarean section was collected on all singleton births > or =2500 g from the Icelandic Birth Registration and from maternity case records. The same data were obtained for all perinatal deaths > or =2500 g excluding malformed infants irrespective of mode of delivery. The caesarean section and perinatal mortality rates were calculated and the relation between these evaluated by Pearson s correlation coefficient. RESULTS: The total number of deliveries in the study period was 64514 and the mean perinatal mortality rate 6.4/1000 (range: 3.6-9.2/1000). A significant increase was found in the overall caesarean section rate, from 11.6% to 18.2% (p or =2500 g and 8332 were born by caesarean section. There were 111 perinatal deaths among this cohort giving a mean perinatal mortality rate (PNMR) of 1.8/1000 (range 0.8-4.1/1000). While for singleton non-malformed infants the caesarean section rate increased from 10.4% to 16.7% (p or =2500 g was found in this population with a prior low perinatal mortality, neither among primi- nor multiparous women.Ágrip Inngangur: Tíðni fæðinga með keisaraskurði hefur víða margfaldast undanfarna áratugi án þess að burðarmálsdauði (BMD) hafi lækkað á sama tíma. Á Íslandi hefur keisaraskurðum fjölgað verulega og burðarmálsdauði haldist lágur. Óvíst er um tengsl þar á milli. Flestir keisaraskurðir eru gerðir hjá konum við fulla meðgöngu. Börn sem deyja á burðarmálstíma eru einkum fyrirburar og heildartölur um BMD gefa takmarkaða mynd af því hvort fjölgun keisaraskurða skili sér í færri dauðsföllum barna sem hafa náð eðlilegri fæðingarþyngd. Tilgangur rannsóknarinnar var að meta hugsanleg tengsl keisaraskurða við burðarmálsdauða hjá einburum sem vógu ≥2500 g við fæðingu. Efniviður og aðferðir: Upplýsingar um meðgöngu­lengd, þyngd barns, fjölda barna, upphaf fæðingar og fyrri keisaraskurði kvenna sem fóru í keis­ara­skurð á rannsóknartímanum (1989-2003) voru fengn­ar úr Fæðingaskráningunni og sjúkraskrám. Af þeim voru allar konur með einbura ≥2500 g valdar í rannsóknarhópinn. Sömu upplýsingar voru fengnar um einbura 2≥2500 g án alvarlegra van­skapnaða sem dóu á burðarmálstíma, óháð fæð­ingarmáta. Breytingar á tíðni keisaraskurða og BMD voru metnar með Pearsons fylgnistuðli. Niðurstöður: Alls fæddu 64514 konur 65619 börn árin 1989-2003. Þar af dóu 419 börn á burð­ar­málstíma. BMD breyttist ekki marktækt á rannsóknartíma og var að meðaltali 6,4/1000 (bil: 3,6-9,2/1000). Heildartíðni keisaraskurða hækk­aði marktækt úr 11,6% í 18,2% (p2500 g. Tíðni keis­ara­skurða í rannsóknarhópnum jókst úr 10,4% í 16,7% (p<0,001). Ekki var marktæk fylgni við BMD í þessum hópi, en meðaltalstíðni BMD var 1,8/1000 (bil: 0,8-4,1/1000). Meðal frumbyrja jókst keisaratíðnin úr 12% í 18%, einnig án fylgni við BMD (meðaltal 0,6/1000). Ályktanir: Fjölgun keisaraskurða við fæðingu einbura með fæðingarþyngd ≥2500 g hefur ekki leitt til marktækrar fækkunar dauðsfalla hjá þess­um hópi barna á síðastliðnum 15 árum

State and Transition Models in Space and Time – Using STMs to Understand Broad Patterns of Ecosystem Change in Iceland

Managing ecological systems sustainably requires a deep understanding of ecosystem structure and the processes driving their dynamics. Conceptual models can lead to improved management, by providing a framework for organizing knowledge about a system and identifying the causal agents of change. We developed state-and-transition models (STMs) to describe landscape changes in Iceland over three historical periods with different human influence, from pre-settlement to present days. Our models identified the set of possible states, transitions and thresholds in these ecosystems and their changes over time. To illustrate the use of these models for predicting and improving management interventions, we applied our present-day STM to a case study in the central highlands of Iceland and monitored ecosystem changes within an ongoing field experiment with two management interventions (grazing exclusion and fertilization) in areas experiencing contrasting stages of degradation. The results of the experiment broadly align with the predictions of the model and underscore the importance of conceptual frameworks for adaptive management, where the best available knowledge is used to continuously refine and update the models

Epidemiology and association with outcomes of polypharmacy in patients undergoing surgery: retrospective, population-based cohort study

BACKGROUND: The aim of this study was to determine the prevalence of preoperative polypharmacy and the incidence of postoperative polypharmacy/hyper-polypharmacy in surgical patients and their association with adverse outcomes. METHODS: This was a retrospective, population-based cohort study among patients older than or equal to 18 years undergoing surgery at a university hospital between 2005 and 2018. Patients were categorized based on the number of medications: non-polypharmacy (fewer than 5); polypharmacy (5-9); and hyper-polypharmacy (greater than or equal to 10). The 30-day mortality, prolonged hospitalization (greater than or equal to 10 days), and incidence of readmission were compared between medication-use categories. RESULTS: Among 55 997 patients, the prevalence of preoperative polypharmacy was 32.3 per cent (95 per cent c.i. 33.5 to 34.3) and the prevalence of hyper-polypharmacy was 25.5 per cent (95 per cent c.i. 25.2 to 25.9). Thirty-day mortality was higher for patients exposed to preoperative hyper-polypharmacy (2.3 per cent) and preoperative polypharmacy (0.8 per cent) compared with those exposed to non-polypharmacy (0.6 per cent) (P < 0.001). The hazards ratio (HR) of long-term mortality was higher for patients exposed to hyper-polypharmacy (HR 1.32 (95 per cent c.i. 1.25 to 1.40)) and polypharmacy (HR 1.07 (95 per cent c.i. 1.01 to 1.14)) after adjustment for patient and procedural variables. The incidence of longer hospitalization (greater than or equal to 10 days) was higher for hyper-polypharmacy (11.3 per cent) and polypharmacy (6.3 per cent) compared with non-polypharmacy (4.1 per cent) (P < 0.001). The 30-day incidence of readmission was higher for patients exposed to hyper-polypharmacy (10.2 per cent) compared with polypharmacy (6.1 per cent) and non-polypharmacy (4.8 per cent) (P < 0.001). Among patients not exposed to polypharmacy, the incidence of new postoperative polypharmacy/hyper-polypharmacy was 33.4 per cent (95 per cent c.i. 32.8 to 34.1), and, for patients exposed to preoperative polypharmacy, the incidence of postoperative hyper-polypharmacy was 16.3 per cent (95 per cent c.i. 16.0 to 16.7). CONCLUSION: Preoperative polypharmacy and new postoperative polypharmacy/hyper-polypharmacy are common and associated with adverse outcomes. This highlights the need for increased emphasis on optimizing medication usage throughout the perioperative interval

Thermal model of lava in Mt. Agung during December 2017 episodes derived from Integrated SENTINEL 2A and ASTER remote sensing datasets

Publisher's version (útgefin grein)In the beginning of December 2017, Mt. Agung eruption powered down to minor ash emissions and on the middle of December, aerial photographs of the crater were taken by Indonesia Centre of Volcanology and Geological Hazard Mitigation (PVMBG) showing a steadily growing lava occupying approximately one third of the crater. 3D digital elevation model (DEM) of crater were created by PVMBG during and before the eruption, corresponded to lava volume around 2 x 10−2 km3 has been filled the crater. Here we present a method for deriving thermal model within the lava during eruption on 8 and 9 December 2017 using observations from multi infrared satellite SENTINEL 2A and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). We use Thermal Eruption Index (TEI) based on the Shortwave infrared (SWIR) on SENTINEL 2A and Thermal Infrared (TIR) on ASTER, allowing us to differentiate thermal domain within the lava. This study has successfully produced model of sub-pixel temperature (Th), radiant flux (Φrad) and crust thickness model of lava (Δh). The subpixel temperature and radiant flux during the eruption is in the range 655 to 975 °C and 179 MW respectively. The crust thickness model of the lava in the range of 9 to 14 m and the total volume of lava crust during this period is estimated at 3 x 10−3 km3. The combination of infrared satellite remote sensing data shows a potential for fast and efficient classification of difference thermal domains and derive thermal model of lava.The first author has been supported by the Indonesia Endowment Fund for Education (LPDP), Institute of Earth Science and Vinir Vatnajökuls during his PhD project.Peer Reviewe

Environmental pressure from the 2014–15 eruption of Bárðarbunga volcano, Iceland

The effusive six months long 2014-2015 Bárðarbunga eruption (31 August-27 February) was the largest in Iceland for more than 200 years, producing 1.6 ± 0.3 km3 of lava. The total SO2 emission was 11 ± 5 Mt, more than the amount emitted from Europe in 2011. The ground level concentration of SO2 exceeded the 350 μg m−3 hourly average health limit over much of Iceland for days to weeks. Anomalously high SO2 concentrations were also measured at several locations in Europe in September. The lowest pH of fresh snowmelt at the eruption site was 3.3, and 3.2 in precipitation 105 km away from the source. Elevated dissolved H2SO4, HCl, HF, and metal concentrations were measured in snow and precipitation. Environmental pressures from the eruption and impacts on populated areas were reduced by its remoteness, timing, and the weather. The anticipated primary environmental pressure is on the surface waters, soils, and vegetation of Iceland

Evidence of Segregated Spawning in a Single Marine Fish Stock: Sympatric Divergence of Ecotypes in Icelandic Cod?

There is increasing recognition of intraspecific diversity and population structure within marine fish species, yet there is little direct evidence of the isolating mechanisms that maintain it or documentation of its ecological extent. We analyzed depth and temperature histories collected by electronic data storage tags retrieved from 104 Atlantic cod at liberty ≥1 year to evaluate a possible isolating mechanisms maintaining population structure within the Icelandic cod stock. This stock consists of two distinct behavioral types, resident coastal cod and migratory frontal cod, each occurring within two geographically distinct populations. Despite being captured together on the same spawning grounds, we show the behavioral types seem reproductively isolated by fine-scale differences in spawning habitat selection, primarily depth. Additionally, the different groups occupied distinct seasonal thermal and bathymetric niches that generally demonstrated low levels of overlap throughout the year. Our results indicate that isolating mechanisms, such as differential habitat selection during spawning, might contribute to maintaining diversity and fine-scale population structure in broadcast-spawning marine fishes

Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis

Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis

Association of Genetically Predicted Lipid Levels With the Extent of Coronary Atherosclerosis in Icelandic Adults.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadImportance: Genetic studies have evaluated the influence of blood lipid levels on the risk of coronary artery disease (CAD), but less is known about how they are associated with the extent of coronary atherosclerosis. Objective: To estimate the contributions of genetically predicted blood lipid levels on the extent of coronary atherosclerosis. Design, setting, and participants: This genetic study included Icelandic adults who had undergone coronary angiography or assessment of coronary artery calcium using cardiac computed tomography. The study incorporates data collected from January 1987 to December 2017 in Iceland in the Swedish Coronary Angiography and Angioplasty Registry and 2 registries of individuals who had undergone percutaneous coronary interventions and coronary artery bypass grafting. For each participant, genetic scores were calculated for levels of non-high-density lipoprotein cholesterol (non-HDL-C), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides, based on reported effect sizes of 345 independent, lipid-associated variants. The genetic scores' predictive ability for lipid levels was assessed in more than 87 000 Icelandic adults. A mendelian randomization approach was used to estimate the contribution of each lipid trait. Exposures: Genetic scores for levels of non-HDL-C, LDL-C, HDL-C, and triglycerides. Main outcomes and measures: The extent of angiographic CAD and coronary artery calcium quantity. Results: A total of 12 460 adults (mean [SD] age, 65.1 [10.7] years; 8383 men [67.3%]) underwent coronary angiography, and 4837 had coronary artery calcium assessed by computed tomography. A genetically predicted increase in non-HDL-C levels by 1 SD (38 mg/dL [to convert to millimoles per liter, multiply by 0.0259]) was associated with greater odds of obstructive CAD (odds ratio [OR], 1.83 [95% CI, 1.63-2.07]; P = 2.8 × 10-23). Among patients with obstructive CAD, there were significant associations with multivessel disease (OR, 1.26 [95% CI, 1.11-1.44]; P = 4.1 × 10-4) and 3-vessel disease (OR, 1.47 [95% CI, 1.26-1.72]; P = 9.2 × 10-7). There were also significant associations with the presence of coronary artery calcium (OR, 2.04 [95% CI, 1.70-2.44]; P = 5.3 × 10-15) and loge-transformed coronary artery calcium (effect, 0.70 [95% CI, 0.53-0.87]; P = 1.0 × 10-15). Genetically predicted levels of non-HDL-C remained associated with obstructive CAD and coronary artery calcium extent even after accounting for the association with LDL-C. Genetically predicted levels of HDL-C and triglycerides were associated individually with the extent of coronary atherosclerosis, but not after accounting for the association with non-HDL cholesterol. Conclusions and relevance: In this study, genetically predicted levels of non-HDL-C were associated with the extent of coronary atherosclerosis as estimated by 2 different methods. The association was stronger than for genetically predicted levels of LDL-C. These findings further support the notion that non-HDL-C may be a better marker of the overall burden of atherogenic lipoproteins than LDL-C.deCODE genetics/Amgen Inc