| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- 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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| 7. |
- 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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| 8. |
- Kraai, Imke, et al.
(författare)
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The value of telemonitoring and ICT-guided disease management in heart failure: Results from the IN TOUCH study
- 2016
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Ingår i: International Journal of Medical Informatics. - : ELSEVIER IRELAND LTD. - 1386-5056 .- 1872-8243. ; 85:1, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- Aim: It is still unclear whether telemonitoring reduces hospitalization and mortality in heart failure (HF) patients and whether adding an Information and Computing Technology-guided-disease-management-system (ICT-guided-DMS) improves clinical and patient reported outcomes or reduces healthcare costs. Methods: A multicenter randomized controlled trial was performed testing the effects of INnovative ICT-guided-DMS combined with Telemonitoring in OUtpatient clinics for Chronic HF patients (IN TOUCH) with in total 179 patients (mean age 69 years; 72% male; 77% in New York Heart Association Classification (NYHA) III-IV; mean left ventricular ejection fraction was 28%). Patients were randomized to ICT-guided-DMS or to ICT-guided-DMS + telemonitoring with a follow-up of nine months. The composite endpoint included mortality, HF-readmission and change in health-related quality of life (HR-QoL). Results: In total 177 patients were eligible for analyses. The mean score of the primary composite endpoint was -0.63 in ICT-guided-DMS vs. -0.73 in ICT-guided-DMS + telemonitoring (mean difference 0.1,95% CI: -0.67 +0.82, p = 0.39). All-cause mortality in ICT-guided-DMS was 12% versus 15% in ICT-guided-DMS + telemonitoring (p = 0.27); HF-readmission 28% vs. 27% p = 0.87; all-cause readmission was 49% vs. 51% (p = 0.78). HR-QoL improved in most patients and was equal in both groups. Incremental costs were 1360 in favor of ICT-guided-DMS. ICT-guided-DMS + telemonitoring had significantly fewer HF-outpatient-clinic visits (p < 0.01). Conclusion: ICT-guided-DMS + telemonitoring for the management of HF patients did not affect the primary and secondary endpoints. However, we did find a reduction in visits to the HF-outpatient clinic in this group suggesting that telemonitoring might be safe to use in reorganizing HF-care with relatively low costs. (C) 2015 The Authors. Published by Elsevier Ireland Ltd. This is an open access article under the CC BY-NC-ND license (http://cleativecommons.org/licenses/by-nc-nd/4.0/).
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| 9. |
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| 10. |
- van Deursen, Vincent M., et al.
(författare)
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Prognostic Value of Plasma Neutrophil Gelatinase-Associated Lipocalin for Mortality in Patients With Heart Failure
- 2014
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Ingår i: Circulation Heart Failure. - : American Heart Association. - 1941-3289 .- 1941-3297. ; 7:1, s. 35-42
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Tidskriftsartikel (refereegranskat)abstract
- Background In patients with heart failure, renal dysfunction is associated with a poor outcome. We aimed to assess the prognostic value of plasma neutrophil gelatinase-associated lipocalin (NGAL), a novel marker of renal tubular damage, in patients with heart failure with or without renal dysfunction, and compare it with 2 frequently used biomarkers of chronic kidney disease. Methods and Results Plasma NGAL, estimated glomerular filtration rate (eGFR), and cystatin C were assessed in 562 patients with heart failure. Chronic kidney disease was defined as eGFRless than60 mL/min per 1.73 m(2). Outcome was all-cause mortality at 36 months. Mean age was 7111 years, 61% were men, and 97% were in New York Heart Association functional class II/III. Mean baseline eGFR was 54 +/- 20 mL/min per 1.73 m(2), mean cystatin C was 11.2 (7.7-16.2) mg/L, and median plasma NGAL was 85 (60-123) ng/mL. Higher plasma NGAL levels were independently associated with an increased risk of all-cause mortality, in patients with and without chronic kidney disease (hazard ratio [per SD increase in log NGAL]=1.45 [1.22-1.72]; Pless than0.001 and hazard ratio=1.51 [1.06-2.16]; P=0.023, respectively). Similarly, both in patients with high and low cystatin C (median cut-off), higher plasma NGAL levels were independently associated with an increased risk of all-cause mortality. Moreover, when NGAL was entered in the multivariable risk prediction model, eGFR (P=0.616) and cystatin C (P=0.937) were no longer associated with mortality. Conclusions Plasma NGAL predicts mortality in patients with heart failure, both in patients with and without chronic kidney disease and is a stronger predictor for mortality than the established renal function indices eGFR and cystatin C.
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