| 51. |
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| 52. |
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| 55. |
- Elffers, Jan, et al.
(författare)
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Trade-offs between time and memory in a tighter model of CDCL SAT solvers
- 2016
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Ingår i: 19th International Conference on Theory and Applications of Satisfiability Testing, SAT 2016. - Cham : Springer. - 9783319409696 ; , s. 160-176
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Konferensbidrag (refereegranskat)abstract
- A long line of research has studied the power of conflict- driven clause learning (CDCL) and how it compares to the resolution proof system in which it searches for proofs. It has been shown that CDCL can polynomially simulate resolution even with an adversarially chosen learning scheme as long as it is asserting. However, the simulation only works under the assumption that no learned clauses are ever forgot- ten, and the polynomial blow-up is significant. Moreover, the simulation requires very frequent restarts, whereas the power of CDCL with less frequent or entirely without restarts remains poorly understood. With a view towards obtaining results with tighter relations between CDCL and resolution, we introduce a more fine-grained model of CDCL that cap- tures not only time but also memory usage and number of restarts. We show how previously established strong size-space trade-offs for resolution can be transformed into equally strong trade-offs between time and memory usage for CDCL, where the upper bounds hold for CDCL with- out any restarts using the standard 1UIP clause learning scheme, and the (in some cases tightly matching) lower bounds hold for arbitrarily frequent restarts and arbitrary clause learning schemes.
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| 57. |
- François, P., et al.
(författare)
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First Stars. III. A detailed elemental abundance study of four extremely metal-poor giant stars
- 2003
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 403:3, s. 1105-1114
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports detailed abundance analyses for four extremelymetal-poor (XMP) giant stars with [Fe/H]<-3.8, based onhigh-resolution, high-S/N spectra from the ESO VLT (Kueyen/UVES) and LTEmodel atmosphere calculations. The derived [alpha /Fe] ratios in oursample exhibit a small dispersion, confirming previous findings in theliterature, i.e. a constant overabundance of the alpha -elements with avery small (if any) dependence on [Fe/H]. In particular, the very smallscatter we determine for [Si/Fe] suggests that this element shows aconstant overabundance at very low metallicity, a conclusion which couldnot have been derived from the widely scattered [Si/Fe] values reportedin the literature for less metal-poor stars. For the iron-peak elements,our precise abundances for the four XMP stars in our sample confirm thedecreasing trend of Cr and Mn with decreasing [Fe/H], as well as theincreasing trend for Co and the absence of any trend for Sc and Ni. Incontrast to the significant spread of the ratios [Sr/Fe] and [Ba/Fe], wefind [Sr/Ba] in our sample to be roughly solar, with a much lowerdispersion than previously found for stars in the range -3.5 < [Fe/H]< -2.5.Based on observations made with the ESO Very Large Telescope at ParanalObservatory, Chile (Large Programme ID 165.N-0276(A)).The complete version of Table 5 is only available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp:/ /cdsweb.u-strasbg.fr/cgi-bin/qcat?J /A+A/403/1105
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| 59. |
- Glinatsi, D., et al.
(författare)
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Head-to-head comparison of aggressive conventional therapy and three biological treatments and comparison of two de-escalation strategies in patients who respond to treatment: Study protocol for a multicenter, randomized, open-label, blinded-assessor, phase 4 study
- 2017
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Ingår i: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: New targeted therapies and improved treatment strategies have dramatically improved the outcomes of patients with rheumatoid arthritis (RA). However, it is unknown whether different early aggressive interventions can induce stable remission or a low-active disease state that can be maintained with conventional synthetic disease-modifying antirheumatic drug (csDMARD) therapy, and whether they differ in efficacy and safety. The Nordic Rheumatic Diseases Strategy Trials And Registries (NORD-STAR) study will assess and compare (1) the proportion of patients who achieve remission in a head-to-head comparison between csDMARD plus glucocorticoid therapy and three different biological DMARD (bDMARD) therapies with different modes of action and (2) two de-escalation strategies in patients who respond to first-line therapy. Methods/design: In a pragmatic, 80-160-week, multicenter, randomized, open-label, assessor-blinded, phase 4 study, 800 patients with early RA (symptom duration less than 24 months) are randomized 1:1:1:1 to one of four different treatment arms: (1) aggressive csDMARD therapy with methotrexate + sulphasalazine + hydroxychloroquine + i.a. glucocorticoids (arm 1A) or methotrexate + prednisolone p.o. (arm 1B), (2) methotrexate + certolizumab-pegol, (3) methotrexate + abatacept, or (4) methotrexate + tocilizumab. The primary clinical endpoint is the proportion of patients reaching Clinical Disease Activity Index (CDAI) remission at week 24. Patients in stable remission over 24 consecutive weeks enter part 2 of the study earliest after 48 weeks. Patients not achieving sustained CDAI remission over 24 consecutive weeks, exit the study after 80 weeks. In part 2, patients are re-randomized to two different de-escalation strategies, either immediate or delayed (after 24 weeks) tapering, followed by cessation of study medication. All patients remain on stable doses of methotrexate. The primary clinical endpoint in part 2 is the proportion of patients in remission (CDAI ≤2.8) 24 weeks after initiating treatment de-escalation. Radiographic assessment will be performed regularly throughout the trial, and blood and urine samples will be stored in a biobank for later biomarker analyses. Discussion: NORD-STAR is the first investigator-initiated, randomized, early RA trial to compare (1) csDMARD and three different bDMARD therapies head to head and (2) two different de-escalation strategies. The trial has the potential to identify which treatment strategy to apply in early RA to achieve the best possible outcomes for both patients and society. Trial registration:NCT01491815and NCT02466581. Registered on 8 December 2011 and May 2015, respectively. EudraCT: 2011-004720-35 © 2017 The Author(s).
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