Iron and iron/manganese ratio in forage from Icelandic sheep farms: relation to scrapie

This study was undertaken in order to examine whether any connection existed between the amounts of iron in forage and the sporadic occurrence of scrapie observed in certain parts of Iceland. As iron and manganese are considered antagonistic in plants, calculation of the Fe/Mn ratios was also included by using results from Mn determination earlier performed in the same samples. Forage samples (n = 170) from the summer harvests of 2001–2003, were collected from 47 farms for iron and manganese analysis. The farms were divided into four categories: 1. Scrapie-free farms in scrapie-free areas (n = 9); 2. Scrapie-free farms in scrapie-afflicted areas (n = 17); 3. Scrapie-prone farms (earlier scrapie-afflicted, restocked farms) (n = 12); 4. Scrapie-afflicted farms (n = 9). Farms in categories 1 and 2 are collectively referred to as scrapie-free farms. The mean iron concentration in forage samples from scrapie-afflicted farms was significantly higher than in forage samples from farms in the other scrapie categories (P = 0.001). The mean Fe/Mn ratio in forage from scrapie-afflicted farms was significantly higher than in forage from scrapie-free and scrapie-prone farms (P < 0.001). The results indicated relative dominance of iron over manganese in forage from scrapie-afflicted farms as compared to farms in the other categories. Thus thorough knowledge of iron, along with manganese, in soil and vegetation on sheep farms could be a pivot in studies on sporadic scrapie

Afterglow Light Curves and Broken Power Laws: A Statistical Study

In gamma-ray burst research it is quite common to fit the afterglow light curves with a broken power law to interpret the data. We apply this method to a computer simulated population of afterglows and find systematic differences between the known model parameters of the population and the ones derived from the power law fits. In general, the slope of the electron energy distribution is overestimated from the pre-break light curve slope while being underestimated from the post-break slope. We also find that the jet opening angle derived from the fits is overestimated in narrow jets and underestimated in wider ones. Results from fitting afterglow light curves with broken power laws must therefore be interpreted with caution since the uncertainties in the derived parameters might be larger than estimated from the fit. This may have implications for Hubble diagrams constructed using gamma-ray burst data.Comment: 4 pages, 5 figures, accepted for publication in ApJ Letter

Case report: hypertension with hypokalemia in pregnant woman

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenCase report: Hypertension with hypokalemia in pregnant womanSjúkratilfelli Þrjátíu og níu ára þunguð kona í annarri meðgöngu greindist með háþrýsting og kalíumbrest í 25. viku. Ekki saga um háþrýsting í fyrri meðgöngu fimm árum áður, en þá fæddi hún dreng með Downs heilkenni. Í færslum í sjúkraskrá frá heimilislækni skömmu fyrir getnað var getið kvartana um þyngsli fyrir brjósti og þreytu. Blóðþrýstingsgildi á bilinu 140-150/90-100 mmHg og kalíumgildi í serum var 3,3 mmól/l mælt tvisvar, með viku millibili. Í fyrsta mæðraeftirliti á heilsugæslu í 12. viku mældist blóðþrýstingur 180/100 mmHg. Sjúklingi var því vísað í frekara eftirlit á Miðstöð mæðraverndar. Blóðþrýstingur mældist þar hár næstu tíu vikurnar, eða á bilinu 140-170/80-95 mmHg. Helstu kvartanir á þessum tíma voru höfuðverkur ásamt þreytu. Orsökin talin vera háþrýstingur af óþekktri orsök (essential hypertension). Engin merki voru um prótín í þvagi

Multi-wavelength constraints on cosmic-ray leptons in the Galaxy

Cosmic rays (CRs) interact with the gas, the radiation field and the magnetic field in the Milky Way, producing diffuse emission from radio to gamma rays. Observations of this diffuse emission and comparison with detailed predictions are powerful tools to unveil the CR properties and to study CR propagation. We present various GALPROP CR propagation scenarios based on current CR measurements. The predicted synchrotron emission is compared to radio surveys, and synchrotron temperature maps from WMAP and Planck, while the predicted interstellar gamma-ray emission is compared to Fermi-LAT observations. We show how multi-wavelength observations of the Galactic diffuse emission can be used to help constrain the CR lepton spectrum and propagation. Finally we discuss how radio and microwave data could be used in understanding the diffuse Galactic gamma-ray emission observed with Fermi-LAT, especially at low energies.Comment: 8 pages, 5 figures; in Proceedings of the 34th International Cosmic Ray Conference (ICRC 2015), The Hague (The Netherlands); Oral contributio

Clinical guidelines from Landspitali University Hospital on the diagnosis and treatment of acute asthma exacerbation

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn Skoða/Opna(view/open)janúar 2003 voru gefnar út á vegum Scottish Intercollegiate Guidelines (SIGN) og The British Thoracic Society vandaðar leiðbeiningar um grein-ingu og meðferð bráðrar versnunar á astma. Birt-ust leiðbeiningarnar í Thorax 2003; 58 (Suppl 1) og eru aðgengilegar á pdf-formi á slóðinni: www.sign.ac.uk/guidelines/fulltext/63/index.html Ástæða þess að talið var æskilegt að þýða og staðfæra hluta leiðbeininganna hér á landi var að um algengt bráðavandamál er að ræða sem læknar þurfa að vera færir um að bregðast við. Því er til mikilla bóta ef hægt er að nálgast einfaldar og skýrar leiðbeiningar um greiningu og meðferð þessara sjúklinga. Rétt er að benda á að heildarleiðbeiningarnar frá SIGN eru mjög ítarlegar og taka meðal annars til astma í börnum, astma á meðgöngu auk almenns fróðleiks um greiningu og meðferð sjúkdómsins. Vinnuhópurinn sem tók að sér að þýða og staðfæra þessar leiðbeiningar um bráðaversnun á astma var skipaður eftirtöldum: Hjalti Már Björnsson, deildarlæknir Gunnar Guðmundsson, lungnalæknir Jón Steinar Jónsson, heilsugæslulæknir Unnur Steina Björnsdóttir, ofnæmislæknir Inga Sif Ólafsdóttir, deildarlæknir Ari J. Jóhannesson, formaður nefndar um klínískar leiðbeiningar á Landspítala. Þar sem um er að ræða gagnreynda (evidence based) ferla voru óverulegar breytingar gerðar á þeim við þýðingu. Nánari sundurliðun á öllum breytingum sem gerðar voru má finna á vefsvæði kínískra leiðbeininga á www.landspitali.is Uppsetning ferlanna miðast við að auðvelt sé að prenta þá út og hafa á veggspjöldum þar sem þeirra er þörf

Comprehensive multi-wavelength modelling of the afterglow of GRB050525A

The Swift era has posed a challenge to the standard blast-wave model of Gamma Ray Burst (GRB) afterglows. The key observational features expected within the model are rarely observed, such as the achromatic steepening (`jet-break') of the light curves. The observed afterglow light curves showcase additional complex features requiring modifications within the standard model. Here we present optical/NIR observations, millimeter upper limits and comprehensive broadband modelling of the afterglow of the bright GRB 0505025A, detected by Swift. This afterglow cannot be explained by the simplistic form of the standard blast-wave model. We attempt modelling the multi-wavelength light curves using (i) a forward-reverse shock model, (ii) a two-component outflow model and (iii) blast-wave model with a wind termination shock. The forward-reverse shock model cannot explain the evolution of the afterglow. The two component model is able to explain the average behaviour of the afterglow very well but cannot reproduce the fluctuations in the early X-ray light curve. The wind termination shock model reproduces the early light curves well but deviates from the global behaviour of the late-time afterglow.Comment: 20 pages, 6 figures, accepted for publication in MNRA

A Bayesian approach to linking archaeological, paleoenvironmental and documentary datasets relating to the settlement of Iceland (Landnám)

YesIcelandic settlement (Landnám) period farmsteads offer opportunities to explore the nature and timing of anthropogenic activities and environmental impacts of the first Holocene farming communities. We employ Bayesian statistical modelling of archaeological, paleoenvironmental and documentary datasets to present a framework for improving chronological robustness of archaeological events. Specifically, we discuss events relevant to the farm Hrísbrú, an initial and complex settlement site in southwest Iceland. We demonstrate that tephra layers are key in constraining reliable chronologies, especially when combined with related datasets and treated in a Bayesian framework. The work presented here confirms earlier interpretations of the chronology of the site while providing increased confidence in the robustness of the chronology. Most importantly, integrated modelling of AMS radiocarbon dates on Hordeum vulgare grains, palynological data, documented evidence from textual records and typologically diagnostic artefacts yield increased dating reliability. The analysis has also shown that AMS radiocarbon dates on bone collagen need further scrutiny. Specifically for the Hrísbrú farm, first anthropogenic footprint palynomorph taxa are estimated to around AD 830–881 (at 95.4% confidence level), most likely before the tephra fall out of AD 877 ± 1 (the Landnám tephra layer), demonstrating the use of arable fields before the first known structures were built at Hrísbrú (AD 874–951) and prior to the conventionally accepted date of the settlement of Iceland. Finally, we highlight the importance of considering multidisciplinary factors for other archaeological and paleoecological studies of early farming communities of previously uninhabited island areas

Winter mass balance of Drangajökull ice cap (NW Iceland) derived from satellite sub-meter stereo images

Sub-meter resolution, stereoscopic satellite images allow for the generation of accurate and high-resolution digital elevation models (DEMs) over glaciers and ice caps. Here, repeated stereo images of Drangajökull ice cap (NW Iceland) from Pléiades and WorldView2 (WV2) are combined with in situ estimates of snow density and densification of firn and fresh snow to provide the first estimates of the glacier-wide geodetic winter mass balance obtained from satellite imagery. Statistics in snow- and ice-free areas reveal similar vertical relative accuracy (<  0.5 m) with and without ground control points (GCPs), demonstrating the capability for measuring seasonal snow accumulation. The calculated winter (14 October 2014 to 22 May 2015) mass balance of Drangajökull was 3.33 ± 0.23 m w.e. (meter water equivalent), with ∼ 60 % of the accumulation occurring by February, which is in good agreement with nearby ground observations. On average, the repeated DEMs yield 22 % less elevation change than the length of eight winter snow cores due to (1) the time difference between in situ and satellite observations, (2) firn densification and (3) elevation changes due to ice dynamics. The contributions of these three factors were of similar magnitude. This study demonstrates that seasonal geodetic mass balance can, in many areas, be estimated from sub-meter resolution satellite stereo images.This study was funded by the University of Iceland (UI) Research Fund. Pleiades images were acquired at research price thanks to the CNES ISIS program (http://www.isis-cnes.fr). The WV2 DEM was obtained through the ArcticDEM project. This work is a contribution to the Rannis grant of excellence project, ANATILS. Collaboration and travels between IES and LEGOS were funded by the Jules Verne research fund and the TOSCA program from the French Space Agency, CNES. This study used the recent lidar mapping of the glaciers in Iceland that was funded by the Icelandic Research Fund, the Landsvirkjun research fund, the Icelandic Road Administration, the Reykjavik Energy Environmental and Energy Research Fund, the Klima-og Luftgruppen (KoL) research fund of the Nordic Council of Ministers, the Vatnajokull National Park, the organization Friends of Vatnajokull, the National Land Survey of Iceland, the Icelandic Meteorological Office and the UI research fund. The ground-based mass balance measurements on Drangajokull have been jointly funded by Orkubu Vestfjarda (Westfjord Power Company), the National Energy Authority (2004-2009) and the Icelandic Meteorological Office (2009-2015).Peer Reviewe

Modelling GRB021004 by multiple energy injections

GRB021004 is one of the best sampled gamma-ray bursts (GRB) todate, however the nature of its light curve is still being debated. A compilation of multiwavelength (from radio to X-rays) observations, including unpublished optical/near-infrared and millimetre observations, is used to fit a model based on 7 refreshed shocks that took place during the evolution of the afterglow. They imply a total energy release of ∼ 8 × 1051 erg. Analysis of the late photometry reveals that the GRB021004 host is a low extinction (AV ∼ 0.1) starburst galaxy with MB � −22.0