| 1. |
- Abbott, Benjamin W., et al.
(författare)
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Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
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| 2. |
- Fripiat, F., et al.
(författare)
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Macro-nutrient concentrations in Antarctic pack ice: Overall patterns and overlooked processes
- 2017
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Ingår i: Elementa. - : University of California Press. - 2325-1026. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Antarctic pack ice is inhabited by a diverse and active microbial community reliant on nutrients for growth. Seeking patterns and overlooked processes, we performed a large-scale compilation of macro-nutrient data (hereafter termed nutrients) in Antarctic pack ice (306 ice-cores collected from 19 research cruises). Dissolved inorganic nitrogen and silicic acid concentrations change with time, as expected from a seasonally productive ecosystem. In winter, salinity-normalized nitrate and silicic acid concentrations (C∗) in sea ice are close to seawater concentrations (Cw), indicating little or no biological activity. In spring, nitrate and silicic acid concentrations become partially depleted with respect to seawater (C∗ < Cw), commensurate with the seasonal build-up of ice microalgae promoted by increased insolation. Stronger and earlier nitrate than silicic acid consumption suggests that a significant fraction of the primary productivity in sea ice is sustained by flagellates. By both consuming and producing ammonium and nitrite, the microbial community maintains these nutrients at relatively low concentrations in spring. With the decrease in insolation beginning in late summer, dissolved inorganic nitrogen and silicic acid concentrations increase, indicating imbalance between their production (increasing or unchanged) and consumption (decreasing) in sea ice. Unlike the depleted concentrations of both nitrate and silicic acid from spring to summer, phosphate accumulates in sea ice (C∗ > Cw). The phosphate excess could be explained by a greater allocation to phosphorus-rich biomolecules during ice algal blooms coupled with convective loss of excess dissolved nitrogen, preferential remineralization of phosphorus, and/or phosphate adsorption onto metal-organic complexes. Ammonium also appears to be efficiently adsorbed onto organic matter, with likely consequences to nitrogen mobility and availability. This dataset supports the view that the sea ice microbial community is highly efficient at processing nutrients but with a dynamic quite different from that in oceanic surface waters calling for focused future investigations. Copyright © 2017 The Author(s).
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| 5. |
- Burns, Christopher R., et al.
(författare)
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THE CARNEGIE SUPERNOVA PROJECT : LIGHT-CURVE FITTING WITH SNooPy
- 2011
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 141:1, s. 19-
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Tidskriftsartikel (refereegranskat)abstract
- In providing an independent measure of the expansion history of the universe, the Carnegie Supernova Project (CSP) has observed 71 high-z Type Ia supernovae (SNe Ia) in the near-infrared bands Y and J. These can be used to construct rest-frame i-band light curves which, when compared to a low-z sample, yield distance moduli that are less sensitive to extinction and/or decline-rate corrections than in the optical. However, working with NIR observed and i-band rest-frame photometry presents unique challenges and has necessitated the development of a new set of observational tools in order to reduce and analyze both the low-z and high-z CSP sample. We present in this paper the methods used to generate uBVgriYJH light-curve templates based on a sample of 24 high-quality low-z CSP SNe. We also present two methods for determining the distances to the hosts of SN Ia events. A larger sample of 30 low-z SNe Ia in the Hubble flow is used to calibrate these methods. We then apply the method and derive distances to seven galaxies that are so nearby that their motions are not dominated by the Hubble flow.
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| 6. |
- Herfurth, M., et al.
(författare)
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Gait velocity and step length at baseline predict outcome of Nordic walking training in patients with Parkinson's disease
- 2015
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier BV. - 1353-8020. ; 21:4, s. 413-416
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Tidskriftsartikel (refereegranskat)abstract
- Background: The impact of Nordic walking (NW) in Parkinson's disease (PD) has been investigated in several studies but results are inconsistent. This may be due to different cohorts studied and the heterogeneity of their PD symptoms which impact the outcome of NW. This study aimed at determining predictive factors for a positive effect of NW on PD. Methodology and principal findings: Primary outcome was to define the baseline disease-associated and demographic parameters that distinguish patients who demonstrate improvement in the Unified PD rating scale (UPDRS) motor part following NW training ("U+") from those patients with no improvement after the same intervention ("U-"). The potentially predictive parameters were: age, age at onset, disease duration, gait velocity, step length, daily step number, UPDRS-motor part, Berg-Balance-Scale, Parkinson-Neuropsychometric-Dementia-Assessment, verbal-fluency-test and Becks-Depression-Inventory-II. Twenty-two PD patients (H&Y stage 2-2.5) performed twelve weeks of NW training. Eighteen patients were included in the final analysis. Overall, the UPDRS motor part did not improve significantly; however, eight patients had an improvement in the UPDRS motor part from baseline to end of study (U+). When comparing the potentially predictive factors of the 1J(+) cohort with those ten patients who did not improve (U-), there was a notable difference in gait velocity and step length, and showed a significant correlation with an improvement in the UDPRS motor part scores. Conclusion: Gait velocity and step length can predict the outcome of NW training as determined by the UPDRS motor part, indicating that PD patients with only slightly impaired gait performance benefit most. (c) 2015 Elsevier Ltd. All rights reserved.
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| 7. |
- Kattner, ShiAnne, et al.
(författare)
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The Standardizability of Type Ia Supernovae in the Near-Infrared : Evidence for a Peak-Luminosity Versus Decline-Rate Relation in the Near-Infrared
- 2012
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Ingår i: Publications of the Astronomical Society of the Pacific. - : IOP Publishing. - 0004-6280 .- 1538-3873. ; 124:912, s. 114-127
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the standardizability of Type Ia supernovae (SNe Ia) in the near-infrared (NIR) by investigating the correlation between observed peak NIR (Y JH) absolute magnitude and postmaximum B-band decline rate [Delta m(15)(B)]. A sample of 27 low-redshift SNe Ia with well-observed NIR light curves observed by the Carnegie Supernova Project (CSP) between 2004 and 2007 is used. All 27 objects have premaximum coverage in optical bands, with a subset of 13 having premaximum NIR observations as well; coverage of the other 14 begins shortly after NIR maximum brightness. We describe the methods used to derive light-curve parameters (absolute peak magnitudes and decline rates) from both spline-and template-fitting procedures, and we confirm prior findings that fitting templates to SNe Ia light curves in the NIR is problematic due to the diversity of postmaximum behavior of objects that are characterized by similar Delta m(15)(B) values, especially at high decline rates. Nevertheless, we show that NIR light curves can be reasonably fit with a template, especially if the observations begin within 5 days after NIR maximum. SNe Ia appear to be better standardizable candles in the NIR bands than in the optical bands. For the subset of 13 objects in our data set that excludes the highly reddened and fast-declining SNe Ia and includes only those objects for which NIR observations began prior to 5 days after maximum light, we find modest (1.7 sigma) evidence for a peak-luminosity versus decline-rate relation in Y, and stronger evidence (2.8 sigma) in J and H. Using R-V values differing from the canonical value (R-V = 3.1) is shown to have little effect on the results. A Hubble diagram is presented for the NIR bands and the B band. The resulting scatter for the combined NIR bands is 0.13 mag, while the B band produces a scatter of 0.22 mag. Finally, we find evidence for a bimodal distribution in the NIR absolute magnitudes of fast-declining SNe Ia [Delta m(15)(B) > 1.7]. These data suggest that applying a correction to SNe Ia peak luminosities for decline rate is likely to be beneficial in the J and H bands to make SNe Ia more precise distance indicators, but of only marginal importance in the Y band.
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| 8. |
- Stritzinger, Maximilian, et al.
(författare)
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THE DISTANCE TO NGC 1316 (FORNAX A) FROM OBSERVATIONS OF FOUR TYPE Ia SUPERNOVAE
- 2010
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 140:6, s. 2036-2051
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Tidskriftsartikel (refereegranskat)abstract
- The giant elliptical galaxy NGC 1316 (Fornax A) is a well-studied member of the Fornax Cluster and a prolific producer of Type Ia supernovae (SNe Ia), having hosted four observed events since 1980. Here, we present detailed optical-and near-infrared light curves of the spectroscopically normal SN 2006dd. These data are used, along with previously published photometry of the normal SN 1980N and SN 1981D, and the fast-declining, low-luminosity SN 2006mr, to compute independent estimates of the host reddening for each SN, and the distance to NGC 1316. From the three normal SNe, we find a distance of 17.8 +/- 0.3 (random) +/- 0.3 (systematic) Mpc for H-o = 72. Distance moduli derived from the "EBV" and Tripp methods give the values that are mutually consistent with 4%-8%. Moreover, the weighted means of the distance moduli for these three SNe for three methods agree to within 3%. This consistency is encouraging and supports the premise that Type Ia SNe are reliable distance indicators at the 5% precision level or better. On the other hand, the two methods used to estimate the distance of the fast-declining SN 2006mr both yield a distance to NGC 1316 which is 25%-30% larger. This disparity casts doubt on the suitability of fast-declining events for estimating extragalactic distances. Modest-to-negligible host galaxy reddening values are derived for all four SNe. Nevertheless, two of them (SN 2006dd and SN 2006mr) show strong Na I D interstellar lines in the host galaxy system. The strength of this absorption is completely inconsistent with the small reddening values derived from the SN light curves if the gas in NGC 1316 is typical of that found in the interstellar medium of the Milky Way. In addition, the equivalent width of the Na lines in SN 2006dd appears to have weakened significantly some 100-150 days after explosion.
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| 9. |
- Wertheimer, T, et al.
(författare)
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Abatacept as salvage therapy in chronic graft-versus-host disease-a retrospective analysis
- 2021
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Ingår i: Annals of hematology. - : Springer Science and Business Media LLC. - 1432-0584 .- 0939-5555. ; 100:3, s. 779-787
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Tidskriftsartikel (refereegranskat)abstract
- The immunomodulatory fusion protein abatacept has recently been investigated for the treatment of steroid-refractory chronic graft-versus-host disease (cGvHD) in a phase 1 clinical trial. We analyzed the safety and efficacy of abatacept for cGvHD therapy in a retrospective study with 15 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) and received abatacept for cGvHD with a median age of 49 years. Grading was performed as part of the clinical routine according to the National Institute of Health’s (NIH) consensus criteria at initiation of abatacept and 1, 3, 6, 9 and 12 months thereafter. The median time of follow-up was 191 days (range 55–393 days). Best overall response rate (ORR) was 40%. In particular, patients with bronchiolitis obliterans syndrome showed significant clinical improvement and durable responses following abatacept treatment with a response rate of 89% based on improvement in lung severity score (n = 6) or stabilized lung function (n = 4) or both (n = 3). Infectious complications CTCAE °III or higher were observed in 3/15 patients. None of the patients relapsed from the underlying malignancy. Thus, abatacept appears to be a promising treatment option for cGvHD, in particular for patients with lung involvement. However, further evaluation within a phase 2 clinical trial is required.
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| 10. |
- Ågren, John, et al.
(författare)
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Applications of computational thermodynamics
- 2002
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Ingår i: Zeitschrift für Metallkunde. - : Walter de Gruyter GmbH. - 0044-3093. ; 93:2, s. 128-142
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Tidskriftsartikel (refereegranskat)abstract
- The major tools used in applying computational thermodynamics to various problems in materials science are briefly presented and several practical examples are given as illustrations. Solutions to industrial problems, pertaining to the processing of and microstructure development in several different materials, are shown with answers given in graphical form. Solutions to kinetic problems linked with diffusion are also treated. The last section is devoted to the problem of interfacing between thermodynamic computations and applications oriented software.
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| 11. |
- Ågren, John, et al.
(författare)
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Applications of computational thermodynamics
- 2021
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Ingår i: International Journal of Materials Research - Zeitschrift für Metallkunde. - : WALTER DE GRUYTER GMBH. - 1862-5282 .- 2195-8556. ; 93:2, s. 128-142
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Tidskriftsartikel (refereegranskat)abstract
- The major tools used in applying computational thermodynamics to various problems in materials science are briefly presented and several practical examples are given as illustrations. Solutions to industrial problems, pertaining to the processing of and microstructure development in several different materials, are shown with answers given in graphical form. Solutions to kinetic problems linked with diffusion are also treated. The last section is devoted to the problem of interfacing between thermodynamic computations and applications oriented software.
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