| 1. |
- Adolphi, Florian, et al.
(författare)
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Persistent link between solar activity and Greenland climate during the Last Glacial Maximum
- 2014
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Ingår i: Nature Geoscience. - 1752-0908 .- 1752-0894. ; 7:9, s. 662-666
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Tidskriftsartikel (refereegranskat)abstract
- Changes in solar activity have previously been proposed to cause decadal- to millennial-scale fluctuations in both the modern and Holocene climates(1). Direct observational records of solar activity, such as sunspot numbers, exist for only the past few hundred years, so solar variability for earlier periods is typically reconstructed from measurements of cosmogenic radionuclides such as Be-10 and C-14 from ice cores and tree rings(2,3). Here we present a high-resolution Be-10 record from the ice core collected from central Greenland by the Greenland Ice Core Project (GRIP). The record spans from 22,500 to 10,000 years ago, and is based on new and compiled data(4-6). Using C-14 records(7,8) to control for climate-related influences on Be-10 deposition, we reconstruct centennial changes in solar activity. We find that during the Last Glacial Maximum, solar minima correlate with more negative delta O-18 values of ice and are accompanied by increased snow accumulation and sea-salt input over central Greenland. We suggest that solar minima could have induced changes in the stratosphere that favour the development of high-pressure blocking systems located to the south of Greenland, as has been found in observations and model simulations for recent climate(9,10). We conclude that the mechanism behind solar forcing of regional climate change may have been similar under both modern and Last Glacial Maximum climate conditions.
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| 2. |
- 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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| 4. |
- Maret-Ouda, John, et al.
(författare)
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Aspiration pneumonia after antireflux surgery among neurologically impaired children with GERD
- 2020
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Ingår i: Journal of Pediatric Surgery. - : Elsevier BV. - 0022-3468 .- 1531-5037. ; 55:11, s. 2408-2412
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVE: Aspiration pneumonia is a common and serious complication to gastroesophageal reflux disease (GERD) among neurologically impaired children. Medication of GERD does not effectively prevent aspiration pneumonia, and whether antireflux surgery with fundoplication is better in this respect is uncertain. The objective was to determine whether fundoplication prevents aspiration pneumonia among children with neurological impairment and GERD.METHODS: This was a population-based cohort study from Denmark, Finland, Norway and Sweden, consisting of neurologically impaired children with GERD who underwent fundoplication. The risk of aspiration pneumonia before fundoplication (preoperative person-time) was compared with the risk after surgery (postoperative person-time). Multivariable Cox regression provided hazard ratios (HRs) with 95% confidence intervals (CIs). Except for confounding adjusted for by means of the "crossover like" design, the HRs were adjusted for age, sex, year of entry and respiratory diseases.RESULTS: Among 578 patients (median age 3.5 years), the preoperative person-time was 956 years and the postoperative person-time was 3324 years. Fundoplication was associated with 56% decreased overall HR of aspiration pneumonia (HR 0.44, 95% CI 0.27-0.72), and the HRs decreased over time after surgery. The risk of other types of pneumonia than aspiration pneumonia was not clearly decreased after fundoplication (HR 0.79, 95% CI 0.59-1.08). The 30-day mortality rate was 0.7% and the complication rate was 3.6%.CONCLUSIONS: Antireflux surgery decreases, but does not eliminate, the risk of aspiration pneumonia among neurologically impaired children with GERD. Fundoplication may be a treatment option when aspiration pneumonia is a recurrent problem in these children.TYPE OF STUDY: Cohort study.LEVEL OF EVIDENCE: Prognosis study-level I.
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| 5. |
- Roland, P, et al.
(författare)
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A database generator for human brain imaging
- 2001
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Ingår i: TINS - Trends in Neurosciences. - 0166-2236 .- 1878-108X. ; 24:10, s. 562-564
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Tidskriftsartikel (refereegranskat)abstract
- Sharing scientific data containing complex information requires new concepts and new technology. NEUROGENERATOR is a database generator for the neuroimaging community. A database generator is a database that generates new databases. The scientists submit raw PET and fMRI data to NEUROGENERATOR, which then processes the data in a uniform way to create databases of homogenous data suitable for data sharing, met-analysis and modelling the human brain at the systems level. These databases are then distributed to the scientists.
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