| 1. |
- Aad, G., et al.
(författare)
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- 2011
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swepub:Mat__t (refereegranskat)
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| 2. |
- van Haarlem, M. P., et al.
(författare)
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LOFAR : The LOw-Frequency ARray
- 2013
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 556, s. 1-53
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Tidskriftsartikel (refereegranskat)abstract
- LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10–240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. LOFAR’s new capabilities, techniques and modus operandi make it an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results from the commissioning phase of this new radio observatory.
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| 3. |
- Achberger, Christine, 1968, et al.
(författare)
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State of the Climate in 2011
- 2012
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Ingår i: Bulletin of the American Meteorological Society. - 0003-0007. ; 93:7
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale climate patterns influenced temperature and weather patterns around the globe in 2011. In particular, a moderate-to-strong La Nina at the beginning of the year dissipated during boreal spring but reemerged during fall. The phenomenon contributed to historical droughts in East Africa, the southern United States, and northern Mexico, as well the wettest two-year period (2010-11) on record for Australia, particularly remarkable as this follows a decade-long dry period. Precipitation patterns in South America were also influenced by La Nina. Heavy rain in Rio de Janeiro in January triggered the country's worst floods and landslides in Brazil's history. The 2011 combined average temperature across global land and ocean surfaces was the coolest since 2008, but was also among the 15 warmest years on record and above the 1981-2010 average. The global sea surface temperature cooled by 0.1 degrees C from 2010 to 2011, associated with cooling influences of La Nina. Global integrals of upper ocean heat content for 2011 were higher than for all prior years, demonstrating the Earth's dominant role of the oceans in the Earth's energy budget. In the upper atmosphere, tropical stratospheric temperatures were anomalously warm, while polar temperatures were anomalously cold. This led to large springtime stratospheric ozone reductions in polar latitudes in both hemispheres. Ozone concentrations in the Arctic stratosphere during March were the lowest for that period since satellite records began in 1979. An extensive, deep, and persistent ozone hole over the Antarctic in September indicates that the recovery to pre-1980 conditions is proceeding very slowly. Atmospheric carbon dioxide concentrations increased by 2.10 ppm in 2011, and exceeded 390 ppm for the first time since instrumental records began. Other greenhouse gases also continued to rise in concentration and the combined effect now represents a 30% increase in radiative forcing over a 1990 baseline. Most ozone depleting substances continued to fall. The global net ocean carbon dioxide uptake for the 2010 transition period from El Nino to La Nina, the most recent period for which analyzed data are available, was estimated to be 1.30 Pg C yr(-1), almost 12% below the 29-year long-term average. Relative to the long-term trend, global sea level dropped noticeably in mid-2010 and reached a local minimum in 2011. The drop has been linked to the La Nina conditions that prevailed throughout much of 2010-11. Global sea level increased sharply during the second half of 2011. Global tropical cyclone activity during 2011 was well-below average, with a total of 74 storms compared with the 1981-2010 average of 89. Similar to 2010, the North Atlantic was the only basin that experienced above-normal activity. For the first year since the widespread introduction of the Dvorak intensity-estimation method in the 1980s, only three tropical cyclones reached Category 5 intensity level-all in the Northwest Pacific basin. The Arctic continued to warm at about twice the rate compared with lower latitudes. Below-normal summer snowfall, a decreasing trend in surface albedo, and above-average surface and upper air temperatures resulted in a continued pattern of extreme surface melting, and net snow and ice loss on the Greenland ice sheet. Warmer-than-normal temperatures over the Eurasian Arctic in spring resulted in a new record-low June snow cover extent and spring snow cover duration in this region. In the Canadian Arctic, the mass loss from glaciers and ice caps was the greatest since GRACE measurements began in 2002, continuing a negative trend that began in 1987. New record high temperatures occurred at 20 m below the land surface at all permafrost observatories on the North Slope of Alaska, where measurements began in the late 1970s. Arctic sea ice extent in September 2011 was the second-lowest on record, while the extent of old ice (four and five years) reached a new record minimum that was just 19% of normal. On the opposite pole, austral winter and spring temperatures were more than 3 degrees C above normal over much of the Antarctic continent. However, winter temperatures were below normal in the northern Antarctic Peninsula, which continued the downward trend there during the last 15 years. In summer, an all-time record high temperature of -12.3 degrees C was set at the South Pole station on 25 December, exceeding the previous record by more than a full degree. Antarctic sea ice extent anomalies increased steadily through much of the year, from briefly setting a record low in April, to well above average in December. The latter trend reflects the dispersive effects of low pressure on sea ice and the generally cool conditions around the Antarctic perimeter.
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| 4. |
- Blunden, Jessica, et al.
(författare)
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State of the Climate in 2012
- 2013
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 94:8, s. S1-S258
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Tidskriftsartikel (refereegranskat)abstract
- For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Ni a-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in to the effects of La Ni a, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near-or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7 N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global 2 emissions from fossil fuel combustion and cement production reached a record 9.5 +/- 0.5 Pg C in 2011 and a new record of 9.7 +/- 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, 2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.
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| 5. |
- Dahl-Jensen, D., et al.
(författare)
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Eemian interglacial reconstructed from a Greenland folded ice core
- 2013
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 493:7433, s. 489-494
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Tidskriftsartikel (refereegranskat)abstract
- Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 +/- 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 +/- 250 metres, reaching surface elevations 122,000 years ago of 130 +/- 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.
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| 6. |
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| 7. |
- Meyer, Sven, et al.
(författare)
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Neurohormonal and clinical sex differences in heart failure
- 2013
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Ingår i: European Heart Journal. - : Oxford University Press (OUP): Policy B. - 0195-668X .- 1522-9645. ; 34:32, s. 2538-
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Tidskriftsartikel (refereegranskat)abstract
- Despite disparities in pathophysiology and disease manifestation between male and female patients with heart failure, studies focusing on sex differences in biomarkers are scarce. The purpose of this study was to assess sex-specific variation in clinical characteristics and biomarker levels to gain more understanding of the potential pathophysiological mechanisms underlying sex differences in heart failure. less thanbrgreater than less thanbrgreater thanBaseline demographic and clinical characteristics, multiple biomarkers, and outcomes were compared between men and women in 567 patients. The mean age of the study group was 71 11 years and 38 were female. Women were older, had a higher body mass index and left ventricular ejection fraction, more hypertension, and received more diuretic and antidepressant therapy, but less ACE-inhibitor therapy compared with men. After 3 years, all-cause mortality was lower in women than men (37.0 vs. 43.9, multivariable hazard ratio 0.64; 95 confidence interval 0.450.92, P 0.016). Levels of biomarkers related to inflammation [C-reactive protein, pentraxin 3, growth differentiation factor 15 (GDF-15), and interleukin 6] and extracellular matrix remodelling (syndecan-1 and periostin) were significantly lower in women compared with men. N-terminal pro-brain natriuretic peptide, TNF-R1a, and GDF-15 showed the strongest interaction between sex and mortality. less thanbrgreater than less thanbrgreater thanFemale heart failure patients have a distinct clinical presentation and better outcomes compared with male patients. The lower mortality was independent of differences in clinical characteristics, but differential sex associations between several biomarkers and mortality might partly explain the survival difference.
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| 8. |
- Kragelund, C., et al.
(författare)
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Scandinavian fellowship for oral pathology and oral medicine : guidelines for oral pathology and oral medicine in the dental curriculum
- 2012
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Ingår i: European journal of dental education. - Hoboken : Wiley-Blackwell. - 1396-5883 .- 1600-0579. ; 16:4, s. 246-253
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Tidskriftsartikel (refereegranskat)abstract
- In Scandinavia, as in many European countries, most patients consult their general dentist once a year or more. This gives the dentist a unique opportunity and an obligation to make an early diagnosis of oral diseases, which is beneficial for both the patient and the society. Thus, the dentist must have knowledge of clinical symptoms, local and systemic signs and clinical differential diagnoses to make an accurate diagnosis. The dentist must be competent in selecting appropriate diagnostic tests, for example, tissue biopsy and microbiological samples, and conducting them correctly, as well as in interpreting test results and taking appropriate action accordingly. Furthermore, the dentist must be aware of diseases demanding multidisciplinary cooperation and be able to recognise his/her professional limitation, and to refer to other specialists when required. The dental curriculum changes over time as new approaches, treatments and diagnostic possibilities develop. Likewise, the role of the dentist in the community changes and may vary in different countries. As members of the Scandinavian Fellowship for Oral Pathology and Oral Medicine and subject representatives of oral pathology and oral medicine, we feel obliged to contribute to the discussion of how the guidelines of the dental curriculum support the highest possible standards of dental education. This article is meant to delineate a reasonable standard of oral pathology and oral medicine in the European dental curriculum and to guide subject representatives in curriculum development and planning. We have created an advisory topic list in oral pathology and oral medicine.
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| 9. |
- Kragelund, C, et al.
(författare)
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Scandinavian fellowship for oral pathology and oral medicine : statement on oral pathology and oral medicine in the European dental curriculum
- 2010
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Ingår i: Journal of Oral Pathology & Medicine. - : Wiley. - 0904-2512 .- 1600-0714. ; 39:10, s. 800-801
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: For many years, dentists have migrated between the Scandinavian countries without an intentionally harmonized dental education. The free movement of the workforce in the European Union has clarified that a certain degree of standardization or harmonization of the European higher education acts, including the dental education, is required. As a result of the Bologna process, the Association for Dental Education in Europe and the thematic network DentEd have generated guidelines in the document 'Profile and Competences for the European Dentist' (PCD). This document is meant to act as the leading source in revisions of dental curricula throughout Europe converging towards a European Dental Curriculum. In order to render the best conditions for future curriculum revisions providing the best quality dentist we feel obliged to analyse and comment the outlines of oral pathology and oral medicine in the PCD.METHODS: The representatives agreed upon definitions of oral pathology and oral medicine, and competences in oral pathology and oral medicine that a contemporary European dentist should master. The competences directly related to oral pathology and oral medicine were identified, within the PCD.RESULTS: The subject representatives suggested eighteen additions and two rewordings of the PCD, which all were substantiated by thorough argumentation.PERSPECTIVES: Hopefully, this contribution will find support in future revisions of the PCD in order to secure the best quality dental education.
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| 10. |
- van der Wel, Gerko, et al.
(författare)
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Using high-resolution tritium profiles to quantify the effects of melt on two Spitsbergen ice cores
- 2011
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Ingår i: Journal of Glaciology. - : International Glaciological Society. - 0022-1430 .- 1727-5652. ; 57:206, s. 1087-1097
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Tidskriftsartikel (refereegranskat)abstract
- Ice cores from small ice caps provide valuable climatic information, additional to that of Greenland and Antarctica. However, their integrity is usually compromised by summer meltwater percolation. To determine to what extent this can affect such ice cores, we performed high-resolution tritium measurements on samples from two ice cores from Spitsbergen covering the period AD1955-75. The very sharp and distinct peaks in the tritium precipitation record are subject to several post-depositional processes. We developed a model that uses the precipitation record as input and incorporates the three most important processes (radioactive decay, isotope diffusion and meltwater percolation). Results are compared with measured tritium and density profiles. Both ice-core records contain sharp bomb peaks in the pre-1963 period. It is shown that these peaks would be much smoother in the absence of melt. In this case the main effect of melt and the refreezing of percolation water is the formation of ice layers that form barriers for firn diffusion; thus melt paradoxically results in better preservation of the annual isotope signals. Conversely, for the period after 1963 the main effect of melt is a stronger smoothing of the tritium profiles.
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