112 research outputs found

    Modeling Historic Rangeland Management and Grazing Pressures in Landscapes of Settlement

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    Defining historic grazing pressures and rangeland management is vital if early landscape threshold crossing and long–term trajectories of landscape change are to be properly understood. In this paper we use a new environmental simulation model, Búmodel, to assess two contrasting historical grazing landscapes in Mývatnssveit Iceland for two key periods—the colonization period (ca. Landnám, A.D. 872–1000) and the early eighteenth century A.D. Results suggest that there were spatial and temporal variations in productivity and grazing pressure within and between historic grazing areas and indicate that land degradation was not an inevitable consequence of the livestock grazing introduced with settlement. The results also demonstrate the significance of grazing and livestock management strategies in preventing overgrazing, particularly under cooler climatic conditions. The model enables detailed consideration of historic grazing management scenarios and their associated landscape pressures

    The Iceland–Faroe warm-water flow towards the Arctic estimated from satellite altimetry and in situ observations

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    The inflow of warm and saline Atlantic water to the Arctic Mediterranean (Nordic Seas and Arctic Ocean) between Iceland and the Faroes (IF inflow) is the strongest Atlantic inflow branch in terms of volume transport and is associated with a large transport of heat towards the Arctic. The IF inflow is monitored in a section east of the Iceland–Faroe Ridge (IFR) by use of sea level anomaly (SLA) data from satellite altimetry, a method that has been calibrated by in situ observations gathered over 2 decades. Monthly averaged surface velocity anomalies calculated from SLA data were strongly correlated with anomalies measured by moored acoustic Doppler current profilers (ADCPs) with consistently higher correlations when using the reprocessed SLA data released in December 2021 rather than the earlier version. In contrast to the earlier version, the reprocessed data also had the correct conversion factor between sea level slope and surface velocity required by geostrophy. Our results show that the IF inflow crosses the IFR in two separate branches. The Icelandic branch is a jet over the Icelandic slope with average surface speed exceeding 20 cm s−1, but it is narrow and shallow with an average volume transport of less than 1 Sv (106 m3 s−1). Most of the Atlantic water crosses the IFR close to its southernmost end in the Faroese branch. Between these two branches, water from the Icelandic branch turns back onto the ridge in a retroflection with a recirculation over the northernmost bank on the IFR. Combining multi-sensor in situ observations with satellite SLA data, monthly mean volume transport of the IF inflow has been determined from January 1993 to December 2021. The IF inflow is part of the Atlantic Meridional Overturning Circulation (AMOC), which is expected to weaken under continued global warming. Our results show no weakening of the IF inflow. Annually averaged volume transport of Atlantic water through the monitoring section had a statistically significant (95 % confidence level) increasing trend of (0.12±0.10) Sv per decade. Combined with increasing temperature, this caused an increase of 13 % in the heat transport, relative to 0 ∘C, towards the Arctic of the IF inflow over the 29 years of monitoring. The near-bottom layer over most of the IFR is dominated by cold water of Arctic origin that may contribute to the overflow across the ridge. Our observations confirm a dynamic link between the overflow and the Atlantic water flow above. The results also provide support for a previously posed hypothesis that this link may explain the difficulties in reproducing observed transport variations in the IF inflow in numerical ocean models, with consequences for its predictability under climate change.</p

    Glyphosate and AMPA in human urine of HBM4EU-aligned studies: part B adults

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    Within HBM4EU, human biomonitoring (HBM) studies measuring glyphosate (Gly) and aminomethylphosphonic acid (AMPA) in urine samples from the general adult population were aligned and quality-controlled/assured. Data from four studies (ESB Germany (2015-2020); Swiss HBM4EU study (2020); DIET-HBM Iceland (2019-2020); ESTEBAN France (2014-2016)) were included representing Northern and Western Europe. Overall, median values were below the reported quantification limits (LOQs) (0.05-0.1 microg/L). The 95th percentiles (P95) ranged between 0.24 and 0.37 microg/L urine for Gly and between 0.21 and 0.38 microg/L for AMPA. Lower values were observed in adults compared to children. Indications exist for autonomous sources of AMPA in the environment. As for children, reversed dosimetry calculations based on HBM data in adults did not lead to exceedances of the ADI (proposed acceptable daily intake of EFSA for Gly 0.1 mg/kg bw/day based on histopathological findings in the salivary gland of rats) indicating no human health risks in the studied populations at the moment. However, the controversy on carcinogenicity, potential endocrine effects and the absence of a group ADI for Gly and AMPA induce uncertainty to the risk assessment. Exposure determinant analysis showed few significant associations. More data on specific subgroups, such as those occupationally exposed or living close to agricultural fields or with certain consumption patterns (vegetarian, vegan, organic food, high cereal consumer), are needed to evaluate major exposure sources

    Pollution from the 2014–15 Bárðarbunga eruption monitored by snow cores from the Vatnajökull glacier, Iceland

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    The chemical composition of Icelandic rain and snow is dominated by marine aerosols, however human and volcanic activity can also affect these compositions. The six month long 2014-15 Bárdarbunga volcanic eruption was the largest in Iceland for more than 200years and it released into the atmosphere an average of 60kt/day SO 2 , 30kt/day CO 2 , 500t/day HCl and 280t/day HF. To study the effect of this eruption on the winter precipitation, snow cores were collected from the Vatnajökull glacier and the highlands northeast of the glacier. In addition to 29 bulk snow cores from that precipitated from September 2014 until March 2015, two cores were sampled in 21 and 44 increments to quantify the spatial and time evolution of the chemical composition of the snow.The pH and chemical compositions of melted snow samples indicate that snow has been affected by the volcanic gases emitted during the Bárdarbunga eruption. The pH of the melted bulk snow cores ranged from 4.41 to 5.64 with an average value of 5.01. This is four times greater H + activity than pure water saturated with the atmospheric CO 2 . The highest concentrations of volatiles in the snow cores were found close to the eruption site as predicted from CALPUFF SO 2 gas dispersion quality model. The anion concentrations (SO 4 , Cl, and F) were higher and the pH was lower compared to equivalent snow samples collected during 1997-2006 from the unpolluted Icelandic Langjökull glacier. Higher SO 4 and Cl concentrations in the snow compared with the unpolluted rainwater of marine origin confirm the addition of a non-seawater SO 4 and Cl. The δ 34 S isotopic composition confirms that the sulphur addition is of volcanic aerosol origin.The chemical evolution of the snow with depth reflects changes in the lava effusion and gas emission rates. Those rates were the highest at the early stage of the eruption. Snow that fell during that time, represented by samples from the deepest part of the snow cores, had the lowest pH and highest concentrations of SO 4 , F, Cl and metals, compared with snow that fell later in the winter. Also the Al concentration, did exceed World Health Organisation drinking water standard of 3.7μmol/kg in the lower part of the snow core closest to the eruption site.Collected snow represents the precipitation that fell during the eruption period. Nevertheless, only minor environmental impacts are evident in the snow due to its interaction with the volcanic aerosol gases. In addition, the microbial communities identified in the snow that fell during the eruption were similar to those found in snow from other parts of the Arctic, confirming an insignificant impact of this eruption on the snow microecology

    Is team sport the key to getting everybody active, every day? A systematic review of physical activity interventions aimed at increasing girls' participation in team sport

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    Background: It is estimated that 21% of boys and 16% of girls in England meet recommended physical activity guidelines. Team sport has the potential to increase physical activity levels; however, studies show that gender-based factors can influence girls’ participation in team sport. Furthermore, evidence for the effectiveness of interventions promoting team sport among girls is limited. This systematic review aimed to assess the impact of physical activity interventions on secondary school-aged girls’ (aged 11-18 years) participation in team sport and to identify potential strategies for increasing participation. Methods: Electronic databases and grey literature were systematically searched for studies of interventions targeting team sport participation among girls in the UK. Results were exported to Refworks, duplicates removed and eligible studies identified. Extracted data included: participant details, such as sample size and age; components of the intervention; outcomes assessed; and each study was quality appraised. Due to heterogeneity across studies, results were presented narratively. Results: Four studies sourced from the grey literature met the inclusion criteria. Findings suggest that physical activity interventions can encourage girls to try new sports, but evidence is limited in relation to sustained participation. Potential strategies for promoting participation included: consultation with girls, implementation of appropriate peer-leaders and friendship group strategies, early intervention and consideration of intervention setting. Conclusions: This review highlights the limited availability of evidence on the effectiveness of physical activity interventions for promoting team sport participation among girls in the UK. Findings indicate that future research is needed to improve the methodological quality of complex intervention evaluation. Physical activity interventions may have the potential to encourage girls to try team sport, but their impact on sustained participation, and subsequent physical activity outcomes, is less apparent

    Setting the stage for health: Salutogenesis in midwifery professional knowledge in three European countries

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    There is a lack of systematic evidence concerning health orientation in maternity practice in the current climate of risk avoidance. The midwifery professional project is orientated toward the preservation of normal physiological processes during the maternity episode. This study investigates accounts of midwives who were working in health-orientated birth settings, to examine if and how they frame a health orientation in professional practice. Twenty-seven narrative interviews were conducted with midwives working in pre-, peri-, and postnatal care in different maternity care settings in Switzerland, Austria, and Germany. In-depth and comparative pattern data analyses were conducted. The distinct practice orientation of the participants was revealed in three main concepts, underpinned by a common framework mirroring the three parameters of the Sense of Coherence (comprehensibility, manageability, and meaningfulness) described in Aaron Antonovsky's salutogenic theory. The midwives’ implicit salutogenic knowledge shaped their reported actions in supporting mothers, fathers, and families to have health-promoting experiences in maternity care. These results suggest that an implicit health orientation in maternity care practice can be prefered through examination of the practice reports of midwives working in settings that have a health-promoting philosophy. Implications for midwifery practice and research are discussed. Consideration is given to the relevance of the results for debates about avoiding overtreatment and for the operationalization of salutogenic theory in health care practice

    History and structure of the closed pedigreed population of Icelandic Sheepdogs

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    <p>Abstract</p> <p>Background</p> <p>Dog breeds lose genetic diversity because of high selection pressure. Breeding policies aim to minimize kinship and therefore maintain genetic diversity. However, policies like mean kinship and optimal contributions, might be impractical. Cluster analysis of kinship can elucidate the population structure, since this method divides the population in clusters of related individuals. Kinship-based analyses have been carried out on the entire Icelandic Sheepdog population, a sheep-herding breed.</p> <p>Results</p> <p>Analyses showed that despite increasing population size and deliberately transferring dogs, considerable genetic diversity has been lost. When cluster analysis was based on kinships calculated seven generation backwards, as performed in previous studies, results differ markedly from those based on calculations going back to the founder-population, and thus invalidate recommendations based on previous research. When calculated back to the founder-population, kinship-based clustering reveals the distribution of genetic diversity, similarly to strategies using mean kinship.</p> <p>Conclusion</p> <p>Although the base population consisted of 36 Icelandic Sheepdog founders, the current diversity is equivalent to that of only 2.2 equally contributing founders with no loss of founder alleles in descendants. The maximum attainable diversity is 4.7, unlikely achievable in a non-supervised breeding population like the Icelandic Sheepdog. Cluster analysis of kinship coefficients can provide a supporting tool to assess the distribution of available genetic diversity for captive population management.</p

    Evidence of unidirectional hybridization and second‐generation adult hybrid between the two largest animals on Earth, the fin and blue whales

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    Biodiversity in the oceans has dramatically declined since the beginning of the industrial era, with accelerated loss of marine biodiversity impairing the ocean's capacity to maintain vital ecosystem services. A few organisms epitomize the damaging and long‐lasting effects of anthropogenic exploitation: some whale species, for instance, were brought to the brink of extinction, with their population sizes reduced to such low levels that may have cause a significant disruption to their reproductive dynamics and facilitated hybridization events. The incidence of hybridization is nevertheless believed to be rare and very little information exist on its directionality. Here, using genetic markers, we show that all but one whale hybrid sample collected in Icelandic waters originated from the successful mating of male fin whale and female blue whale, thus suggesting unidirectional hybridization. We also demonstrate for the first time the existence of a second‐generation adult (male) hybrid resulting from a backcross between a female hybrid and a pure male fin whale. The incidence of hybridization events between fin and blue whales is likely underestimated and the observed unidirectional hybridization (for F1 and F2 hybrids) is likely to induce a reproductive loss in blue whale, which may represent an additional challenge to its recovery in the Atlantic Ocean compared to other rorquals

    Habitat variability and faunal zonation at the Ægir Ridge, a canyon-like structure in the deep Norwegian Sea

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    The Ægir Ridge System (ARS) is an ancient extinct spreading axis in the Nordic seas extending from the upper slope east of Iceland (∼550 m depth), as part of its Exclusive Economic Zone (EEZ), to a depth of ∼3,800 m in the Norwegian basin. Geomorphologically a rift valley, the ARS has a canyon-like structure that may promote increased diversity and faunal density. The main objective of this study was to characterize benthic habitats and related macro- and megabenthic communities along the ARS, and the influence of water mass variables and depth on them. During the IceAGE3 expedition (Icelandic marine Animals: Genetics and Ecology) on RV Sonne in June 2020, benthic communities of the ARS were surveyed by means of a remotely-operated vehicle (ROV) and epibenthic sledge (EBS). For this purpose, two working areas were selected, including abyssal stations in the northeast and bathyal stations in the southwest of the ARS. Video and still images of the seabed were usedtoqualitatively describebenthic habitats based on the presence of habitat-forming taxa and the physical environment. Patterns of diversity and community composition of the soft-sediment macrofauna, retrieved from the EBS, were analyzed in a semiquantitative manner. These biological data were complemented by producing high-resolution bathymetric maps using the vessel’s multi-beam echosounder system. As suspected, we were able to identify differences in species composition and number of macro- and megafaunal communities associated with a depth gradient. A biological canyon effect became evident in dense aggregates of megafaunal filter feeders and elevated macrofaunal densities. Analysis of videos and still images from the ROV transects also led to the discovery of a number ofVulnerable Marine Ecosystems (VMEs) dominated by sponges and soft corals characteristic of the Arctic region. Directions for future research encompass a more detailed, quantitative study of the megafauna and more coherent sampling over the entire depth range in order to fully capture the diversity of the habitats and biota of the region. The presence of sensitive biogenic habitats, alongside seemingly high biodiversity and naturalness are supportive of ongoing considerations of designating part of the ARS as an “Ecologically and Biologically Significant Area” (EBSA)

    Persistent Chlamydia Pneumoniae serology is related to decline in lung function in women but not in men. Effect of persistent Chlamydia pneumoniae infection on lung function

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    <p>Abstract</p> <p>Background</p> <p><it>Chlamydia pneumoniae </it>(C pn) infection causes an acute inflammation in the respiratory system that may become persistent, but little is known about the long-term respiratory effects of C pn infections. Aim: To estimate the long term respiratory effects of C pn with change in forced expiratory volume in one second (FEV<sub>1</sub>) and forced vital capacity (FVC) as a main outcome variable.</p> <p>Methods</p> <p>The study comprised of 1109 subjects (500 men and 609 women, mean age 28 ± 6 years) that participated in the Reykjavik Heart Study of the Young. Spirometry and blood samples for measurements of IgG antibodies for C pn were done at inclusion and at the end of the follow-up period (mean follow-up time 27 ± 4 years).</p> <p>Results</p> <p>Having IgG against C pn at both examinations was significantly associated to a larger decrease in FEV<sub>1 </sub>(6 mL/year) and FVC (7 mL/year) in women but not in men. In women the association between C pn and larger FEV<sub>1 </sub>decline was only found in women that smoked at baseline where having C pn IgG was associated with 10 mL/year decline compared to smokers without C pn IgG. These results were still significant after adjustment for age, smoking and change in body weight.</p> <p>Conclusion</p> <p>Our results indicate that persistent C pn serology is related to increased decline in lung function in women but not in men. This effect was, however, primarily found in smoking women. This study is a further indication that the pathophysiological process leading to lung impairment may differ between men and women.</p
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