| 1. |
- Aad, G., et al.
(författare)
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- 2011
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swepub:Mat__t (refereegranskat)
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| 11. |
- 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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| 12. |
- Arndt, D. S., et al.
(författare)
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STATE OF THE CLIMATE IN 2017
- 2018
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 99:8, s. S1-S310
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Forskningsöversikt (refereegranskat)
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| 13. |
- 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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| 14. |
- Arndt, D. S., et al.
(författare)
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State of the Climate in 2016
- 2017
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 98:8, s. S1-S280
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Tidskriftsartikel (refereegranskat)abstract
- In 2016, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued to increase and reach new record highs. The 3.5 +/- 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58-year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 +/- 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800000 years. One of the strongest El Nino events since at least 1950 dissipated in spring, and a weak La Nina evolved later in the year. Owing at least in part to the combination of El Nino conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44 degrees C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0 degrees C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8 degrees C, representing a 3.5 degrees C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute similar to 7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01 degrees C. The global sea surface temperature trend for the 21st century-to-date of +0.162 degrees C decade(-1) is much higher than the longer term 1950-2016 trend of +0.100 degrees C decade(-1). Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins-the North Atlantic, and eastern and western North Pacific-experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir-Simpson category 5 intensity level. The strong El Nino at the beginning of the year that transitioned to a weak La Nina contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses.
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| 15. |
- Spronk, H. M. H., et al.
(författare)
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Atherothrombosis and Thromboembolism : Position Paper from the Second Maastricht Consensus Conference on Thrombosis
- 2018
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Ingår i: Thrombosis and Haemostasis. - : SCHATTAUER GMBH-VERLAG MEDIZIN NATURWISSENSCHAFTEN. - 0340-6245 .- 2567-689X. ; 118:2, s. 229-250
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Forskningsöversikt (refereegranskat)abstract
- Atherothrombosis is a leading cause of cardiovascular mortality and long-term morbidity. Platelets and coagulation proteases, interacting with circulating cells and in different vascular beds, modify several complex pathologies including atherosclerosis. In the second Maastricht Consensus Conference on Thrombosis, this theme was addressed by diverse scientists from bench to bedside. All presentations were discussed with audience members and the results of these discussions were incorporated in the final document that presents a state-of-the-art reflection of expert opinions and consensus recommendations regarding the following five topics:1. Risk factors, biomarkers and plaque instability: In atherothrombosis research, more focus on the contribution of specific risk factors like ectopic fat needs to be considered; definitions of atherothrombosis are important distinguishing different phases of disease, including plaque (in) stability; proteomic and metabolomics data are to be added to genetic information.2. Circulating cells including platelets and atherothrombosis: Mechanisms of leukocyte and macrophage plasticity, migration, and transformation in murine atherosclerosis need to be considered; diseasemechanism-based biomarkers need to be identified; experimental systems are needed that incorporatewhole-blood flow to understand how red blood cells influence thrombus formation and stability; knowledge on platelet heterogeneity and priming conditions needs to be translated toward the in vivo situation.3. Coagulation proteases, fibrin(ogen) and thrombus formation: The role of factor (F) XI in thrombosis including the lower margins of this factor related to safe and effective antithrombotic therapy needs to be established; FXI is a key regulator in linking platelets, thrombin generation, and inflammatory mechanisms in a renin-angiotensin dependent manner; however, the impact on thrombin-dependent PAR signaling needs further study; the fundamental mechanisms in FXIII biology and biochemistry and its impact on thrombus biophysical characteristics need to be explored; the interactions of red cells and fibrin formation and its consequences for thrombus formation and lysis need to be addressed. Platelet-fibrin interactions are pivotal determinants of clot formation and stability with potential therapeutic consequences.4. Preventive and acute treatment of atherothrombosis and arterial embolism; novel ways and tailoring? The role of protease-activated receptor (PAR)-4 vis a vis PAR-1 as target for antithrombotic therapy merits study; ongoing trials on platelet function test-based antiplatelet therapy adjustment support development of practically feasible tests; risk scores for patients with atrial fibrillation need refinement, taking new biomarkers including coagulation into account; risk scores that consider organ system differences in bleeding may have added value; all forms of oral anticoagulant treatment require better organization, including education and emergency access; laboratory testing still needs rapidly available sensitive tests with short turnaround time.5. Pleiotropy of coagulation proteases, thrombus resolution and ischaemia-reperfusion: Biobanks specifically for thrombus storage and analysis are needed; further studies on novelmodified activated protein C-based agents are required including its cytoprotective properties; new avenues for optimizing treatment of patients with ischaemic stroke are needed, also including novel agents that modify fibrinolytic activity (aimed at plasminogen activator inhibitor-1 and thrombin activatable fibrinolysis inhibitor.
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| 16. |
- 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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| 17. |
- Chazdon, Robin L., et al.
(författare)
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Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics
- 2016
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 2:5
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Tidskriftsartikel (refereegranskat)abstract
- Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services.
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| 18. |
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| 19. |
- Poorter, Lourens, et al.
(författare)
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Wet and dry tropical forests show opposite successional pathways in wood density but converge over time
- 2019
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Ingår i: Nature Ecology & Evolution. - : Nature Publishing Group. - 2397-334X. ; 3:6, s. 928-934
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Tidskriftsartikel (refereegranskat)abstract
- Tropical forests are converted at an alarming rate for agricultural use and pastureland, but also regrow naturally through secondary succession. For successful forest restoration, it is essential to understand the mechanisms of secondary succession. These mechanisms may vary across forest types, but analyses across broad spatial scales are lacking. Here, we analyse forest recovery using 1,403 plots that differ in age since agricultural abandonment from 50 sites across the Neotropics. We analyse changes in community composition using species-specific stem wood density (WD), which is a key trait for plant growth, survival and forest carbon storage. In wet forest, succession proceeds from low towards high community WD (acquisitive towards conservative trait values), in line with standard successional theory. However, in dry forest, succession proceeds from high towards low community WD (conservative towards acquisitive trait values), probably because high WD reflects drought tolerance in harsh early successional environments. Dry season intensity drives WD recovery by influencing the start and trajectory of succession, resulting in convergence of the community WD over time as vegetation cover builds up. These ecological insights can be used to improve species selection for reforestation. Reforestation species selected to establish a first protective canopy layer should, among other criteria, ideally have a similar WD to the early successional communities that dominate under the prevailing macroclimatic conditions.
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| 20. |
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| 21. |
- van der Heide, A, et al.
(författare)
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End-of-life decision-making in six European countries: descriptive study
- 2003
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Ingår i: The Lancet. - 1474-547X. ; 362:9381, s. 345-350
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Tidskriftsartikel (refereegranskat)abstract
- Background Empirical data about end-of-life decision-making practices are scarce. We aimed to investigate frequency and characteristics of end-of-life decision-making practices in six European countries: Belgium, Denmark, Italy, the Netherlands, Sweden, and Switzerland. Methods In all participating countries, deaths reported to death registries were stratified for cause (apart from in Switzerland), and samples were drawn from every stratum. Reporting doctors received a mailed questionnaire about the medical decision-making that had preceded the death of the patient. The data-collection procedure precluded identification of any of the doctors or patients. All deaths arose between June, 2001, and February, 2002. We weighted data to correct for stratification and to make results representative for all deaths: results were presented as weighted percentages. Findings The questionnaire response rate was 75% for the Netherlands, 67% for Switzerland, 62% for Denmark, 61% for Sweden, 59% for Belgium, and 44% for Italy. Total number of deaths studied was 20 480. Death happened suddenly and unexpectedly in about a third of cases in all countries. The proportion of deaths that were preceded by any end-of-life decision ranged between 23% (Italy) and 51% (Switzerland). Administration of drugs with the explicit intention of hastening death varied between countries: about 1% or less in Denmark, Italy, Sweden, and Switzerland, 1.82% in Belgium, and 3.40% in the Netherlands. Large variations were recorded in the extent to which decisions were discussed with patients, relatives, and other caregivers. Interpretation Medical end-of-life decisions frequently precede dying in all participating countries. Patients and relatives are generally involved in decision-making in countries in which the frequency of making these decisions is high.
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| 22. |
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| 23. |
- 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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| 24. |
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| 25. |
- Gei, Maga, et al.
(författare)
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Legume abundance along successional and rainfall gradients in Neotropical forests
- 2018
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Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 2:7
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Tidskriftsartikel (refereegranskat)abstract
- The nutrient demands of regrowing tropical forests are partly satisfied by nitrogen-fixing legume trees, but our understanding of the abundance of those species is biased towards wet tropical regions. Here we show how the abundance of Leguminosae is affected by both recovery from disturbance and large-scale rainfall gradients through a synthesis of forest inventory plots from a network of 42 Neotropical forest chronosequences. During the first three decades of natural forest regeneration, legume basal area is twice as high in dry compared with wet secondary forests. The tremendous ecological success of legumes in recently disturbed, water-limited forests is likely to be related to both their reduced leaflet size and ability to fix N2, which together enhance legume drought tolerance and water-use efficiency. Earth system models should incorporate these large-scale successional and climatic patterns of legume dominance to provide more accurate estimates of the maximum potential for natural nitrogen fixation across tropical forests.
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| 26. |
- Onwuteaka-Philipsen, BD, et al.
(författare)
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End-of-life decision making in Europe and Australia - A physician survey
- 2006
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Ingår i: Archives of Internal Medicine. - 0003-9926. ; 166:8, s. 921-929
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Tidskriftsartikel (refereegranskat)abstract
- Background: The frequencies with which physicians make different medical end-of-life decisions (ELDs) may differ between countries, but comparison between countries has been difficult owing to the use of dissimilar research methods. Methods: A written questionnaire was sent to a random sample of physicians from 9 specialties in 6 European countries and Australia to investigate possible differences in the frequencies of physicians' willingness to perform ELDs and to identify predicting factors. Response rates ranged from 39% to 68% (N= 10 139). Using hypothetical cases, physicians were asked whether they would ( probably) make each of 4 ELDs. Results: In all the countries, 75% to 99% of physicians would withhold chemotherapy or intensify symptom treatment at the request of a patient with terminal cancer. In most cases, more than half of all physicians would also be willing to deeply sedate such a patient until death. However, there was generally less willingness to administer drugs with the explicit intention of hastening death at the request of the patient. The most important predictor of ELDs was a request from a patient with decisional capacity (odds ratio, 2.1-140.0). Shorter patient life expectancy and uncontrollable pain were weaker predictors but were more stable across countries and across the various ELDs (odds ratios, 1.1-2.4 and 0.9-2.4, respectively). Conclusion: Cultural and legal factors seem to influence the frequencies of different ELDs and the strength of their determinants across countries, but they do not change the essence of decision making.
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| 27. |
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| 28. |
- Tromp, Jasper, et al.
(författare)
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Serum Potassium Levels and Outcome in Acute Heart Failure (Data from the PROTECT and COACH Trials)
- 2017
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Ingår i: American Journal of Cardiology. - : EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC. - 0002-9149 .- 1879-1913. ; 119:2, s. 290-296
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Tidskriftsartikel (refereegranskat)abstract
- Serum potassium is routinely measured at admission for acute heart failure (AHF), but information on association with clinical variables and prognosis is limited. Potassium measurements at admission were available in 1,867 patients with AHF in the original cohort of 2,033 patients included in the Patients Hospitalized with acute heart failure and Volume Overload to Assess Treatment Effect on Congestion and Renal FuncTion trial. Patients were grouped according to low potassium (amp;lt;3.5 mEq/l), normal potassium (3.5 to 5.0 mEq/l), and high potassium (amp;gt;5.0 mEq/l) levels. Results were verified in a validation cohort of 1,023 patients. Mean age of patients was 71 +/- 11 years, and 66% were men. Low potassium was present in 115 patients (6%), normal potassium in 1,576 (84%), and high potassium in 176 (9%). Potassium levels increased during hospitalization (0.18 +/- 0.69 mEq/l). Patients with high potassium more often used angiotensin-converting enzyme inhibitors and mineralocorticoid receptor antagonists before admission, had impaired baseline renal function and a better diuretic response (p = 0.005), independent of mineralocorticoid receptor antagonist usage. During 180-day follow-up, a total of 330 patients (18%) died. Potassium levels at admission showed a univariate linear association with mortality (hazard ratio [log] 2.36, 95% confidence interval 1.07 to 5.23; p = 0.034) but not after multivariate adjustment. Changes of potassium levels during hospitalization or potassium levels at discharge were not associated with outcome after multivariate analysis. Results in the validation cohort were similar to the index cohort. In conclusion, high potassium levels at admission are associated with an impaired renal function but a better diuretic response. Changes in potassium levels are common, and overall levels increase during hospitalization. In conclusion, potassium levels at admission or its change during hospitalization are not associated with mortality after multivariate adjustment. (C) 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativeconunons.org/licenses/by/4.0/).
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| 29. |
- Dontje, Manon L, et al.
(författare)
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Daily Physical Activity in Stable Heart Failure Patients
- 2014
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Ingår i: Journal of Cardiovascular Nursing. - : Lippincott Williams & Wilkins. - 0889-4655 .- 1550-5049. ; 29:3, s. 218-226
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:: Physical activity is the only nonpharmacological therapy that is proven to be effective in heart failure (HF) patients in reducing morbidity. To date, little is known about the levels of daily physical activity in HF patients and about related factors.OBJECTIVE:: The objectives of this study were to (a) describe performance-based daily physical activity in HF patients, (b) compare it with physical activity guidelines, and (c) identify related factors of daily physical activity.METHODS:: The daily physical activity of 68 HF patients was measured using an accelerometer (SenseWear) for 48 hours. Psychological characteristics (self-efficacy, motivation, and depression) were measured using questionnaires. To have an indication how to interpret daily physical activity levels of the study sample, time spent on moderate- to vigorous-intensity physical activities was compared with the 30-minute activity guideline. Steps per day was compared with the criteria for healthy adults, in the absence of HF-specific criteria. Linear regression analyses were used to identify related factors of daily physical activity.RESULTS:: Forty-four percent were active for less than 30 min/d, whereas 56% were active for more than 30 min/d. Fifty percent took fewer than 5000 steps per day, 35% took 5000 to 10 000 steps per day, and 15% took more than 10 000 steps per day. Linear regression models showed that New York Heart Association classification and self-efficacy were the most important factors explaining variance in daily physical activity.CONCLUSIONS:: The variance in daily physical activity in HF patients is considerable. Approximately half of the patients had a sedentary lifestyle. Higher New York Heart Association classification and lower self-efficacy are associated with less daily physical activity. These findings contribute to the understanding of daily physical activity behavior of HF patients and can help healthcare providers to promote daily physical activity in sedentary HF patients.
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| 30. |
- Jaarsma, Tiny, et al.
(författare)
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Effect of moderate or intensive disease management program on outcome in patients with heart failure : Coordinating Study Evaluating Outcomes of Advising and Counseling in Heart Failure (COACH).
- 2008
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Ingår i: Archives of Internal Medicine. - : American Medical Association (AMA). - 0003-9926 .- 1538-3679. ; 168:3, s. 316-24
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Heart failure (HF) disease management programs are widely implemented, but data about their effect on outcome have been inconsistent. METHODS: The Coordinating Study Evaluating Outcomes of Advising and Counseling in Heart Failure (COACH) was a multicenter, randomized, controlled trial in which 1023 patients were enrolled after hospitalization because of HF. Patients were assigned to 1 of 3 groups: a control group (follow-up by a cardiologist) and 2 intervention groups with additional basic or intensive support by a nurse specializing in management of patients with HF. Patients were studied for 18 months. Primary end points were time to death or rehospitalization because of HF and the number of days lost to death or hospitalization. RESULTS: Mean patient age was 71 years; 38% were women; and 50% of patients had mild HF and 50% had moderate to severe HF. During the study, 411 patients (40%) were readmitted because of HF or died from any cause: 42% in the control group, and 41% and 38% in the basic and intensive support groups, respectively (hazard ratio, 0.96 and 0.93, respectively; P = .73 and P = .52, respectively). The number of days lost to death or hospitalization was 39 960 in the control group, 33 731 days for the basic intervention group (P = .81), and 34 268 for the intensive support group (P = .49). All-cause mortality occurred in 29% of patients in the control group, and there was a trend toward lower mortality in the intervention groups combined (hazard ratio, 0.85; 95% confidence interval, 0.66-1.08; P = .18). There were slightly more hospitalizations in the 2 intervention groups (basic intervention group, P = .89; and intensive support group, P = .60). CONCLUSIONS: Neither moderate nor intensive disease management by a nurse specializing in management of patients with HF reduced the combined end points of death and hospitalization because of HF compared with standard follow-up. There was a nonsignificant, potentially relevant reduction in mortality, accompanied by a slight increase in the number of short hospitalizations in both intervention groups. Clinical Trial Registry http://trialregister.nl Identifier: NCT 98675639.
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| 31. |
- Jaarsma, T, et al.
(författare)
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[Value of basic and intensive management of patients with heart failure; results of a randomised controlled clinical trial]
- 2008
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Ingår i: Nederlandsch tijdschrift voor geneeskunde. - 0028-2162 .- 1876-8784. ; 152:37, s. 2016-21
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the efficacy of 2 nurse-directed programmes of different intensity for the counselling and follow-up of patients hospitalised for heart failure, compared with standard care by a cardiologist. DESIGN: Multicentre randomised clinical trial (www.trialregister.nl: NCT 98675639). METHOD: A total of 1023 patients were randomized after hospitalisation for heart failure to 1 of 3 treatment strategies: standard care provided by a cardiologist, follow-up care from a cardiologist with basic counselling and support by a nurse specialising in heart failure, or follow-up care from a cardiologist with intensive counselling and support by a nurse specialising in heart failure. Primary end points were the time to rehospitalisation due to heart failure or death and the number of days lost to rehospitalisation or death during the 18-month study period. Data were analysed on an intent-to-treat basis. RESULTS: Mean patient age was 71 years, 38% were women, 50% had mild heart failure and 50% had severe heart failure. During the study, 411 patients (40%) were rehospitalised due to heart failure or died from any cause: 42% in the control group, and 41% and 38% in the basic and intensive support groups, respectively (differences not significant). The time to rehospitalisation or death was similar in the 3 groups: hazard ratios for the basic and intensive support groups versus the control group were 0.96 (95% CI: 0.76-1.21; p = 0.73) and 0.93 (95% CI: 0.73-1.17; p = 0.53), respectively. The number of days lost to rehospitalisation or death was 39,960 in the control group; this number was 15% less in the intervention groups, but the difference was not significant. However, there was a trend toward lower mortality in the intervention groups. In all 3 groups, more visits occurred than planned, which may have had a considerable effect on care, notably in the control group. CONCLUSION: The results of this study indicated that the provision of additional counselling and support by a nurse specialising in heart failure as an adjuvant to intensive follow-up care provided by a cardiologist does not always lead to a reduction in rehospitalisation frequency.
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| 32. |
- Soininen, E.M., et al.
(författare)
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Location of studies and evidence of effects of herbivory on Arctic vegetation: a systematic map
- 2021
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Ingår i: Environmental Evidence. - : BioMed Central (BMC). - 2047-2382. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Herbivores modify the structure and function of tundra ecosystems. Understanding their impacts is necessary to assess the responses of these ecosystems to ongoing environmental changes. However, the effects of herbivores on plants and ecosystem structure and function vary across the Arctic. Strong spatial variation in herbivore effects implies that the results of individual studies on herbivory depend on local conditions, i.e., their ecological context. An important first step in assessing whether generalizable conclusions can be produced is to identify the existing studies and assess how well they cover the underlying environmental conditions across the Arctic. This systematic map aims to identify the ecological contexts in which herbivore impacts on vegetation have been studied in the Arctic. Specifically, the primary question of the systematic map was: “What evidence exists on the effects of herbivores on Arctic vegetation?”.Methods: We used a published systematic map protocol to identify studies addressing the effects of herbivores on Arctic vegetation. We conducted searches for relevant literature in online databases, search engines and specialist websites. Literature was screened to identify eligible studies, defined as reporting primary data on herbivore impacts on Arctic plants and plant communities. We extracted information on variables that describe the ecological context of the studies, from the studies themselves and from geospatial data. We synthesized the findings narratively and created a Shiny App where the coded data are searchable and variables can be visually explored.Review findings: We identified 309 relevant articles with 662 studies (representing different ecological contexts or datasets within the same article). These studies addressed vertebrate herbivory seven times more often than invertebrate herbivory. Geographically, the largest cluster of studies was in Northern Fennoscandia. Warmer and wetter parts of the Arctic had the largest representation, as did coastal areas and areas where the increase in temperature has been moderate. In contrast, studies spanned the full range of ecological context variables describing Arctic vertebrate herbivore diversity and human population density and impact.Conclusions: The current evidence base might not be sufficient to understand the effects of herbivores on Arctic vegetation throughout the region, as we identified clear biases in the distribution of herbivore studies in the Arctic and a limited evidence base on invertebrate herbivory. In particular, the overrepresentation of studies in areas with moderate increases in temperature prevents robust generalizations about the effects of herbivores under different climatic scenarios.
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| 33. |
- van der Wal, Martje H L, et al.
(författare)
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Compliance in heart failure patients : the importance of knowledge and beliefs
- 2006
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 27:4, s. 434-440
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Non-compliance in patients with heart failure (HF) contributes to worsening HF symptoms and may lead to hospitalization. Several smaller studies have examined compliance in HF, but all were limited as they only studied either the individual components of compliance and its related factors or several aspects of compliance without studying the related factors. The aims of this study were to examine all dimensions of compliance and its related factors in one HF population. METHODS AND RESULTS: Data were collected in a cohort of 501 HF patients. Clinical and demographic data were assessed and patients completed questionnaires on compliance, beliefs, knowledge, and self-care behaviour. Overall compliance was 72% in this older HF population. Compliance with medication and appointment keeping was high (>90%). In contrast, compliance with diet (83%), fluid restriction (73%), exercise (39%), and weighing (35%) was markedly lower. Compliance was related to knowledge (OR=5.67; CI 2.87-11.19), beliefs (OR=1.78; CI 1.18-2.69), and depressive symptoms (OR=0.53; CI 0.35-0.78). CONCLUSION: Although some aspects of compliance had an acceptable level, compliance with weighing and exercise were low. In order to improve compliance, an increase of knowledge and a change of patient's beliefs by education and counselling are recommended. Extra attention should be paid to patients with depressive symptoms.
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| 34. |
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| 35. |
- Jaarsma, Tiny, et al.
(författare)
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Design and methodology of the COACH study : a multicenter randomised Coordinating study evaluating Outcomes of Advising and Counselling in Heart failure
- 2004
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Ingår i: European Journal of Heart Failure. - : Wiley. - 1388-9842 .- 1879-0844. ; 6:2, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: While there are data to support the use of comprehensive non-pharmacological intervention programs in patients with heart failure (HF), other studies have not confirmed these positive findings. Substantial differences in the type and intensity of disease management programs make it impossible to draw definitive conclusions about the effectiveness, optimal timing and frequency of interventions. AIMS: 1. To determine the effectiveness of two interventions (basic support vs. intensive support) compared to 'care as usual' in HF patients, on time to first major event (HF readmission or death), quality of life and costs. 2. To investigate the role of underlying mechanisms (knowledge, beliefs, self-care behaviour, compliance) on the effectiveness of the two interventions. METHODS: This is a randomised controlled trial in which 1050 patients with heart failure will be randomised into three treatment arms: care as usual, basic education and support or intensive education and support. Outcomes of this study are; time to first major event (HF hospitalisation or death), quality of life (Minnesota Living with HF Questionnaire, RAND36 and Ladder of Life) and costs. Data will be collected during initial admission and then 1, 6, 12, and 18 months after discharge. In addition, data on knowledge, beliefs, self-care behaviour and compliance will be collected. RESULTS: The study started in January 2002 and results are expected at the end of 2005. CONCLUSIONS: This study will help health care providers in future to make rational and informed choices about which components of a HF management program should be expanded and which components can possibly be deleted.
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| 36. |
- van der Wal, Martje H L, et al.
(författare)
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Compliance with non-pharmacological recommendations and outcome in heart failure patients.
- 2010
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 31:12, s. 1486-93
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: The aim of this prospective study was to investigate the association between compliance with non-pharmacological recommendations (diet, fluid restriction, weighing, exercise) and outcome in patients with heart failure (HF). METHODS AND RESULTS: In total 830 patients after an HF hospitalization participated in the study (age 70 +/- 11; left ventricular ejection fraction 34%). Compliance was measured 1 month after discharge; patients were followed for 18 months. Primary outcomes were the composite of death or HF readmission and the number of unfavourable days. Cox regression analysis was used to determine the association between primary outcome and compliance. Adjustments were made for those variables that were identified as confounders in the association between compliance and outcome. Patients who were non-compliant with at least one of the recommendations had a higher risk of mortality or HF readmission (HR 1.40; P = 0.01). Non-compliance with exercise was associated with an increased risk for mortality or HF readmission (HR 1.48; P < 0.01), while non-compliance with daily weighing was associated with an increased risk of mortality (HR 1.57; P = 0.02). Non-compliance (overall) and non-compliance with exercise were both associated with a higher risk for HF readmission [HR 1.38; P < 0.05(overall) and HR 1.55; P < 0.01(exercise)]. Patients who were overall non-compliant or with weighing and exercise had more unfavourable days than compliant patients. CONCLUSION: Non-compliance with non-pharmacological recommendations in HF patients is associated with adverse outcome.
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| 37. |
- Benthem, P., et al.
(författare)
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Aperture array development for future large radio telescopes
- 2011
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Ingår i: European Conference on Antennas and Propagation 2011, 11-15 April 2011, Rome.
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Konferensbidrag (refereegranskat)abstract
- We present the design of a phased array system for future radio telescopes. This includes a system overview and recent results of the designed and implemented system, the Electronic Multi-Beam Radio Astronomy Concept (EMBRACE). Furthermore, simulations with a full-EM antenna simulator, combined with measurements on actual hardware, will provide information for the next design step, the Aperture Array Verification System (AAVS). With AAVS, we will prove design readiness of this novel array technology.
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| 38. |
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| 39. |
- Vuorinen, Katariina E.M., et al.
(författare)
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Growth rings show limited evidence for ungulates' potential to suppress shrubs across the Arctic
- 2022
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- Global warming has pronounced effects on tundra vegetation, and rising mean temperatures increase plant growth potential across the Arctic biome. Herbivores may counteract the warming impacts by reducing plant growth, but the strength of this effect may depend on prevailing regional climatic conditions. To study how ungulates interact with temperature to influence growth of tundra shrubs across the Arctic tundra biome, we assembled dendroecological data from 20 sites, comprising 1153 individual shrubs and 223 63 annual growth rings. Evidence for ungulates suppressing shrub radial growth was only observed at intermediate summer temperatures (6.5 °C-9 °C), and even at these temperatures the effect was not strong. Multiple factors, including forage preferences and landscape use by the ungulates, and favourable climatic conditions enabling effective compensatory growth of shrubs, may weaken the effects of ungulates on shrubs, possibly explaining the weakness of observed ungulate effects. Earlier local studies have shown that ungulates may counteract the impacts of warming on tundra shrub growth, but we demonstrate that ungulates' potential to suppress shrub radial growth is not always evident, and may be limited to certain climatic conditions.
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| 40. |
- Waldréus, Nana, et al.
(författare)
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Changes in Thirst Intensity During Optimization of Heart Failure Medical Therapy by Nurses at the Outpatient Clinic.
- 2016
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Ingår i: Journal of Cardiovascular Nursing. - : Lippincott Williams & Wilkins. - 0889-4655 .- 1550-5049. ; 31:5, s. E17-E24
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Thirst can be aggravated in patients with heart failure (HF), and optimization of HF medication can have positive impact on thirst.OBJECTIVES: The aims of this study were to describe changes in thirst intensity and to determine factors associated with high thirst intensity during optimization of HF medication.METHODS AND RESULTS: Patients with HF (N = 66) who were referred to an HF clinic for up-titration of HF medication were included. Data were collected during the first visit to the clinic and at the end of the treatment program. Data were dichotomized by the median visual analog scale score for thirst, dividing patients into 2 groups: low thirst intensity (0-20 mm) and high thirst intensity (>20 mm on a visual analog scale of 0-100 mm). In total, 67% of the patients reported a higher thirst intensity after the HF up-titration program. There was no difference in thirst intensity between the patients who reached target doses and those who did not. Plasma urea level (odds ratio, 1.33; 95% confidence interval, 1.07-1.65) and fluid restriction (odds ratio, 6.25; 95% confidence interval, 1.90-20.5) were independently associated with high thirst intensity in patients with HF.CONCLUSIONS: Thirst intensity increased in two-thirds of the patients during a time period of optimization of HF medication. Fluid restriction and plasma urea levels were associated with high thirst intensity.
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