| 1. |
- Abdo, A. A., et al.
(författare)
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Gamma-ray emission concurrent with the nova in the symbiotic binary V407 cygni
- 2010
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 329:5993, s. 817-821
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Tidskriftsartikel (refereegranskat)abstract
- Novae are thermonuclear explosions on a white dwarf surface fueled by mass accreted from a companion star. Current physical models posit that shocked expanding gas from the nova shell can produce x-ray emission, but emission at higher energies has not been widely expected. Here, we report the Fermi Large Area Telescope detection of variable γ-ray emission (0.1 to 10 billion electron volts) from the recently detected optical nova of the symbiotic star V407 Cygni. We propose that the material of the nova shell interacts with the dense ambient medium of the red giant primary and that particles can be accelerated effectively to produce π0 decay γ-rays from proton-proton interactions. Emission involving inverse Compton scattering of the red giant radiation is also considered and is not ruled out.
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| 2. |
- Hudson, Lawrence N, et al.
(författare)
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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
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Tidskriftsartikel (refereegranskat)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
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| 3. |
- Hudson, Lawrence N., et al.
(författare)
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The PREDICTS database : a global database of how local terrestrial biodiversity responds to human impacts
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:24, s. 4701-4735
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Tidskriftsartikel (refereegranskat)abstract
- Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
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| 4. |
- Henden, J-A, et al.
(författare)
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Phase-dependent effect of conservation efforts in cyclically fluctuating populations of Arctic fox (Vulpes lagopus).
- 2009
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 142, s. 2586-2592
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Tidskriftsartikel (refereegranskat)abstract
- Predator populations with demographic cycles driven by multi-annual cycles of their key prey resourcecan be expected to be ‘‘cyclic phase sensitive” to management actions. We explored this by means ofmodelling in the case of the highly endangered Fennoscandian arctic fox population which is driven by4-year population cycles in small rodent prey. By using a model in which the management actionimproved arctic fox vital rate through increased resource availability, we show that arctic fox populationgrowth was most improved when management action was applied in the increase and decrease phase ofthe cycle. Except in the low phase of the cycle, the growth rate was more affected when the managementaction worked through improved reproduction than improved survival. There was a synergistic effect tobe gained by performing management action during multiple phases during a demographic cycle. Thuswe recommend that arctic fox conservation programs ought to be continuous in time, but with the highestintensities of management action in the phases of the cycle in which the target population is mostprone to respond.
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| 5. |
- Schönenberger, Silvia, et al.
(författare)
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Association of General Anesthesia vs Procedural Sedation With Functional Outcome Among Patients With Acute Ischemic Stroke Undergoing Thrombectomy: A Systematic Review and Meta-analysis.
- 2019
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Ingår i: JAMA. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 322:13, s. 1283-1293
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Tidskriftsartikel (refereegranskat)abstract
- General anesthesia during thrombectomy for acute ischemic stroke has been associated with poor neurological outcome in nonrandomized studies. Three single-center randomized trials reported no significantly different or improved outcomes for patients who received general anesthesia compared with procedural sedation.To detect differences in functional outcome at 3 months between patients who received general anesthesia vs procedural sedation during thrombectomy for anterior circulation acute ischemic stroke.MEDLINE search for English-language articles published from January 1, 1980, to July 31, 2019.Randomized clinical trials of adults with a National Institutes of Health Stroke Scale score of at least 10 and anterior circulation acute ischemic stroke assigned to receive general anesthesia or procedural sedation during thrombectomy.Individual patient data were obtained from 3 single-center, randomized, parallel-group, open-label treatment trials with blinded end point evaluation that met inclusion criteria and were analyzed using fixed-effects meta-analysis.Degree of disability, measured via the modified Rankin Scale (mRS) score (range 0-6; lower scores indicate less disability), analyzed with the common odds ratio (cOR) to detect the ordinal shift in the distribution of disability over the range of mRS scores.A total of 368 patients (mean [SD] age, 71.5 [12.9] years; 163 [44.3%] women; median [interquartile range] National Institutes of Health Stroke Scale score, 17 [14-21]) were included in the analysis, including 183 (49.7%) who received general anesthesia and 185 (50.3%) who received procedural sedation. The mean 3-month mRS score was 2.8 (95% CI, 2.5-3.1) in the general anesthesia group vs 3.2 (95% CI, 3.0-3.5) in the procedural sedation group (difference, 0.43 [95% CI, 0.03-0.83]; cOR, 1.58 [95% CI, 1.09-2.29]; P=.02). Among prespecified adverse events, only hypotension (decline in systolic blood pressure of more than 20% from baseline) (80.8% vs 53.1%; OR, 4.26 [95% CI, 2.55-7.09]; P<.001) and blood pressure variability (systolic blood pressure >180 mm Hg or <120 mm Hg) (79.7 vs 62.3%; OR, 2.42 [95% CI, 1.49-3.93]; P<.001) were significantly more common in the general anesthesia group.Among patients with acute ischemic stroke involving the anterior circulation undergoing thrombectomy, the use of protocol-based general anesthesia, compared with procedural sedation, was significantly associated with less disability at 3 months. These findings should be interpreted tentatively, given that the individual trials examined were single-center trials and disability was the primary outcome in only 1 trial.
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| 6. |
- Simonsen, C Z, et al.
(författare)
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Patients Requiring Conversion to General Anesthesia during Endovascular Therapy Have Worse Outcomes: A Post Hoc Analysis of Data from the SAGA Collaboration.
- 2020
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Ingår i: AJNR. American journal of neuroradiology. - 1936-959X. ; 41:12, s. 2298-2302
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Tidskriftsartikel (refereegranskat)abstract
- Endovascular therapy for acute ischemic stroke is often performed with the patient under conscious sedation. Emergent conversion from conscious sedation to general anesthesia is sometimes necessary. The aim of this study was to assess the functional outcome in converted patients compared with patients who remained in conscious sedation and to identify predictors associated with the risk of conversion.Data from 368 patients, included in 3 trials randomizing between conscious sedation and general anesthesia before endovascular therapy (SIESTA, ANSTROKE, and GOLIATH) constituted the study cohort. Twenty-one (11%) of 185 patients randomized to conscious sedation were emergently converted to general anesthesia.Absence of hyperlipidemia seemed to be the strongest predictor of conversion to general anesthesia, albeit a weak predictor (area under curve = 0.62). Sex, hypertension, diabetes, smoking status, atrial fibrillation, blood pressure, size of the infarct, and level and side of the occlusion were not significantly associated with conversion to general anesthesia. Neither age (mean age, 71.3 ± 13.8 years for conscious sedation versus 71.6 ± 12.3 years for converters, P=.58) nor severity of stroke (mean NIHSS score, 17 ± 4 versus 18 ± 4, respectively, P=.27) were significantly different between converters and those who tolerated conscious sedation. The converters had significantly worse outcome with a common odds ratio of 2.67 (P=.015) for a shift toward a higher mRS score compared with the patients remaining in the conscious sedation group.Patients undergoing conversion had significantly worse outcome compared with patients remaining in conscious sedation. No factor was identified that predicted conversion from conscious sedation to general anesthesia.
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