| 21. |
- Liu, E. J., et al.
(författare)
-
Aerial strategies advance volcanic gas measurements at inaccessible, strongly degassing volcanoes
- 2020
-
Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:44
-
Tidskriftsartikel (refereegranskat)abstract
- Volcanic emissions are a critical pathway in Earth's carbon cycle. Here, we show that aerial measurements of volcanic gases using unoccupied aerial systems (UAS) transform our ability to measure and monitor plumes remotely and to constrain global volatile fluxes from volcanoes. Combining multi-scale measurements from ground-based remote sensing, long-range aerial sampling, and satellites, we present comprehensive gas fluxes-3760 ± [600, 310] tons day-1 CO2 and 5150 ± [730, 340] tons day-1 SO2-for a strong yet previously uncharacterized volcanic emitter: Manam, Papua New Guinea. The CO2/ST ratio of 1.07 ± 0.06 suggests a modest slab sediment contribution to the sub-arc mantle. We find that aerial strategies reduce uncertainties associated with ground-based remote sensing of SO2 flux and enable near-real-time measurements of plume chemistry and carbon isotope composition. Our data emphasize the need to account for time averaging of temporal variability in volcanic gas emissions in global flux estimates.
|
|
| 22. |
- Alef, Walter, et al.
(författare)
-
Geodetic data analysis of VGOS experiments
- 2021
-
Ingår i: 2021 34th General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2021.
-
Konferensbidrag (refereegranskat)abstract
- Very Long Baseline Interferometry (VLBI) serves as one of the common geodetic methods to define the global reference frames and monitor Earth's orientation variations. The technical upgrade of the VLBI method known as the VLBI Global Observing System (VGOS) includes a critical re-design of the observed frequencies from the dual band mode (S and X band, i.e. 2 GHz and 8 GHz) to observations in a broadband (2-14 GHz). Since 2019 the first VGOS experiments are available for the geodetic analysis in free access at the International VLBI service for Geodesy and Astrometry (IVS). Also regional-only subnetworks such as European VLBI stations have succeeded already in VGOS mode. Based on these brand-new observations we review the current geodetic data analysis workflow to build a bridge between geodetic observed delays derived from different bands.
|
|
| 23. |
- Baccarani, Michele, et al.
(författare)
-
Chronic myeloid leukemia : an update of concepts and management recommendations of European LeukemiaNet
- 2009
-
Ingår i: Journal of Clinical Oncology. - 0732-183X .- 1527-7755. ; 27:35, s. 6041-6051
-
Forskningsöversikt (refereegranskat)abstract
- PURPOSE: To review and update the European LeukemiaNet (ELN) recommendations for the management of chronic myeloid leukemia with imatinib and second-generation tyrosine kinase inhibitors (TKIs), including monitoring, response definition, and first- and second-line therapy. METHODS: These recommendations are based on a critical and comprehensive review of the relevant papers up to February 2009 and the results of four consensus conferences held by the panel of experts appointed by ELN in 2008. RESULTS: Cytogenetic monitoring was required at 3, 6, 12, and 18 months. Molecular monitoring was required every 3 months. On the basis of the degree and the timing of hematologic, cytogenetic, and molecular results, the response to first-line imatinib was defined as optimal, suboptimal, or failure, and the response to second-generation TKIs was defined as suboptimal or failure. CONCLUSION: Initial treatment was confirmed as imatinib 400 mg daily. Imatinib should be continued indefinitely in optimal responders. Suboptimal responders may continue on imatinb, at the same or higher dose, or may be eligible for investigational therapy with second-generation TKIs. In instances of imatinib failure, second-generation TKIs are recommended, followed by allogeneic hematopoietic stem-cell transplantation only in instances of failure and, sometimes, suboptimal response, depending on transplantation risk.
|
|
| 24. |
- Barbui, Tiziano, et al.
(författare)
-
Philadelphia-Negative Classical Myeloproliferative Neoplasms : Critical Concepts and Management Recommendations From European LeukemiaNet
- 2011
-
Ingår i: Journal of Clinical Oncology. - 0732-183X .- 1527-7755. ; 29:6, s. 761-770
-
Tidskriftsartikel (refereegranskat)abstract
- We present a review of critical concepts and produce recommendations on the management of Philadelphia-negative classical myeloproliferative neoplasms, including monitoring, response definition, first-and second-line therapy, and therapy for special issues. Key questions were selected according the criterion of clinical relevance. Statements were produced using a Delphi process, and two consensus conferences involving a panel of 21 experts appointed by the European LeukemiaNet (ELN) were convened. Patients with polycythemia vera (PV) and essential thrombocythemia (ET) should be defined as high risk if age is greater than 60 years or there is a history of previous thrombosis. Risk stratification in primary myelofibrosis (PMF) should start with the International Prognostic Scoring System (IPSS) for newly diagnosed patients and dynamic IPSS for patients being seen during their disease course, with the addition of cytogenetics evaluation and transfusion status. High-risk patients with PV should be managed with phlebotomy, low-dose aspirin, and cytoreduction, with either hydroxyurea or interferon at any age. High-risk patients with ET should be managed with cytoreduction, using hydroxyurea at any age. Monitoring response in PV and ET should use the ELN clinicohematologic criteria. Corticosteroids, androgens, erythropoiesis-stimulating agents, and immunomodulators are recommended to treat anemia of PMF, whereas hydroxyurea is the first-line treatment of PMF-associated splenomegaly. Indications for splenectomy include symptomatic portal hypertension, drug-refractory painful splenomegaly, and frequent RBC transfusions. The risk of allogeneic stem-cell transplantation-related complications is justified in transplantation-eligible patients whose median survival time is expected to be less than 5 years.
|
|
| 25. |
- Barbuil, Tiziano, et al.
(författare)
-
Philadelphia chromosome-negative classical myeloproliferative neoplasms : revised management recommendations from European LeukemiaNet
- 2018
-
Ingår i: Leukemia. - : Nature Publishing Group. - 0887-6924 .- 1476-5551. ; 32:5, s. 1057-1069
-
Forskningsöversikt (refereegranskat)abstract
- This document updates the recommendations on the management of Philadelphia chromosome-negative myeloproliferative neoplasms (Ph-neg MPNs) published in 2011 by the European LeukemiaNet (ELN) consortium. Recommendations were produced by multiple-step formalized procedures of group discussion. A critical appraisal of evidence by using Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methodology was performed in the areas where at least one randomized clinical trial was published. Seven randomized controlled trials provided the evidence base; earlier phase trials also informed recommendation development. Key differences from the 2011 diagnostic recommendations included: lower threshold values for hemoglobin and hematocrit and bone marrow examination for diagnosis of polycythemia vera (PV), according to the revised WHO criteria; the search for complementary clonal markers, such as ASXL1, EZH2, IDH1/IDH2, and SRSF2 for the diagnosis of myelofibrosis (MF) in patients who test negative for JAK2V617, CALR or MPL driver mutations. Regarding key differences of therapy recommendations, both recombinant interferon alpha and the JAK1/JAK2 inhibitor ruxolitinib are recommended as second-line therapies for PV patients who are intolerant or have inadequate response to hydroxyurea. Ruxolitinib is recommended as first-line approach for MF-associated splenomegaly in patients with intermediate-2 or high-risk disease; in case of intermediate-1 disease, ruxolitinib is recommended in highly symptomatic splenomegaly. Allogeneic stem cell transplantation is recommended for transplant-eligible MF patients with high or intermediate-2 risk score. Allogeneic stem cell transplantation is also recommended for transplant-eligible MF patients with intermediate-1 risk score who present with either refractory, transfusion-dependent anemia, blasts in peripheral blood > 2%, adverse cytogenetics, or high-risk mutations. In these situations, the transplant procedure should be performed in a controlled setting.
|
|
| 26. |
- Burmann, Björn Marcus, 1979, et al.
(författare)
-
Regulation of alpha-synuclein by chaperones in mammalian cells
- 2020
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 577:7788, s. 127-32
-
Tidskriftsartikel (refereegranskat)abstract
- Neurodegeneration in patients with Parkinson's disease is correlated with the occurrence of Lewy bodies-intracellular inclusions that contain aggregates of the intrinsically disordered protein alpha-synuclein(1). The aggregation propensity of alpha-synuclein in cells is modulated by specific factors that include post-translational modifications(2,3), Abelson-kinase-mediated phosphorylation(4,5) and interactions with intracellular machineries such as molecular chaperones, although the underlying mechanisms are unclear(6-8). Here we systematically characterize the interaction of molecular chaperones with alpha-synuclein in vitro as well as in cells at the atomic level. We find that six highly divergent molecular chaperones commonly recognize a canonical motif in alpha-synuclein, consisting of the N terminus and a segment around Tyr39, and hinder the aggregation of alpha-synuclein. NMR experiments(9) in cells show that the same transient interaction pattern is preserved inside living mammalian cells. Specific inhibition of the interactions between alpha-synuclein and the chaperone HSC70 and members of the HSP90 family, including HSP90 beta, results in transient membrane binding and triggers a remarkable re-localization of alpha-synuclein to the mitochondria and concomitant formation of aggregates. Phosphorylation of alpha-synuclein at Tyr39 directly impairs the interaction of alpha-synuclein with chaperones, thus providing a functional explanation for the role of Abelson kinase in Parkinson's disease. Our results establish a master regulatory mechanism of alpha-synuclein function and aggregation in mammalian cells, extending the functional repertoire of molecular chaperones and highlighting new perspectives for therapeutic interventions for Parkinson's disease.
|
|
| 27. |
- Calves, G. M., et al.
(författare)
-
Observations and analysis of phase scintillation of spacecraft signal on the interplanetary plasma
- 2014
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 564
-
Tidskriftsartikel (refereegranskat)abstract
- Aims. The phase scintillation of the European Space Agency's Venus Express (VEX) spacecraft telemetry signal was observed at X-band (lambda = 3.6 cm) with a number of radio telescopes of the European Very Long Baseline Interferometry (VLBI) Network in the period 2009-2013. Methods. We found a phase fluctuation spectrum along the Venus orbit with a nearly constant spectral index of -2.42 +/- 0.25 over the full range of solar elongation angles from 0 degrees to 45 degrees, which is consistent with Kolmogorov turbulence. Radio astronomical observations of spacecraft signals within the solar system give a unique opportunity to study the temporal behaviour of the signal's phase fluctuations caused by its propagation through the interplanetary plasma and the Earth's ionosphere. This gives complementary data to the classical interplanetary scintillation (IPS) study based on observations of the flux variability of distant natural radio sources. Results. We present here our technique and the results on IPS. We compare these with the total electron content for the line of sight through the solar wind. Finally, we evaluate the applicability of the presented technique to phase-referencing VLBI and Doppler observations of currently operational and prospective space missions.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
- Marquardt, Kai S., et al.
(författare)
-
Type Ia supernovae from exploding oxygen-neon white dwarfs
- 2015
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 580
-
Tidskriftsartikel (refereegranskat)abstract
- Context: The progenitor problem of Type Ia supernovae (SNe Ia) is still unsolved. Most of these events are thought to be explosions of carbon-oxygen (CO) white dwarfs (WDs), but for many of the explosion scenarios, particularly those involving the externally triggered detonation of a sub-Chandrasekhar mass WD (sub-M-Ch, WD), there is also a possibility of having an oxygen-neon (ONe) WD as progenitor.Aims: We simulate detonations of ONe WDs and calculate synthetic observables from these models. The results are compared with detonations in CO WDs of similar mass and observational data of SNe Ia.Methods: We perform hydrodynamic explosion simulations of detonations in initially hydrostatic ONe WDs for a range of masses below the Chandrasekhar mass (M-Ch), followed by detailed nucleosynthetic postprocessing with a 384-isotope nuclear reaction network. The results are used to calculate synthetic spectra and light curves, which are then compared with observations of SNe Ia. We also perform binary evolution calculations to determine the number of SNe Ia involving ONe WDs relative to the number of other promising progenitor channels.Results: The ejecta structures of our simulated detonations in sub-M-Ch, ONe WDs are similar to those from CO WDs. There are, however, small systematic deviations in the mass fractions and the ejecta velocities. These lead to spectral features that are systematically less blueshifted. Nevertheless, the synthetic observables of our ONe WD explosions are similar to those obtained from CO models.Conclusions: Our binary evolution calculations show that a significant fraction (3-10%) of potential progenitor systems should contain an ONe WD. The comparison of our ONe models with our CO models of comparable mass (similar to 1.2 M-circle dot) shows that the less blueshifted spectral features fit the observations better, although they are too bright for normal SNe Ia.
|
|
