| 1. |
- Aartsen, M. G., et al.
(författare)
-
Improvement in fast particle track reconstruction with robust statistics
- 2014
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 736, s. 143-149
-
Tidskriftsartikel (refereegranskat)abstract
- The IceCube project has transformed 1 km(3) of deep natural Antarctic ice into a Cherenkov detector Muon neutrinos are detected and their direction is inferred by mapping the light produced by the secondary muon track inside the volume instrumented with photomultipliers. Reconstructing the muon track from the observed light is challenging due to noise, light scattering in the ice medium, and the possibility of simultaneously having multiple muons inside the detector, resulting from the large flux of cosmic ray muons. This paper describes work on two problems: (1) the truck reconstruction problem, in which, given a set of observations, the goal is to recover the track of a muon; and (2) the coincident event problem, which is to determine how many muons are active in the detector during a time window. Rather than solving these problems by developing more complex physical models that are applied at later stages of the analysis, our approach is to augment the detector's early reconstruction with data filters and robust statistical techniques. These can be implemented at the level of on-line reconstruction and, therefore, improve all subsequent reconstructions. Using the metric of median angular resolution, a standard metric for track reconstruction, we improve the accuracy in the initial reconstruction direction by 13%. We also present improvements in measuring the number of muons in coincident events: we can accurately determine the number of muons 98% of the time.
|
|
| 2. |
- Green, Anders, et al.
(författare)
-
Incidence of Cancer and Mortality in Patients from the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) Trial.
- 2014
-
Ingår i: American Journal of Cardiology. - : Elsevier BV. - 1879-1913 .- 0002-9149. ; 114:10, s. 1518-1522
-
Tidskriftsartikel (refereegranskat)abstract
- The Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) clinical trial, including 1,873 patients found an increased risk for cancer with lipid-lowering therapy with ezetimibe/simvastatin 10/40 mg/day, relative to placebo. In a registry-based follow-up study over 21 months from the conclusion of the SEAS trial, new incident cancer and total mortality were investigated in the SEAS study cohort from Denmark, Finland, Norway, Sweden, and the United Kingdom. Among 1,359 subjects eligible for follow-up (73% of the original total cohort), 1,194 had no history of cancer (primary follow-up cohort). New cancers and deaths were identified in the national cancer and mortality registries and classified by an Expert Review Committee. Data were analyzed using Cox proportional-hazards models of new cancers and mortality during follow-up according to treatment group assigned in the SEAS base study and with age, gender, smoking history, and previous cancers as covariates. The primary follow-up cohort had 12 patients with new cancers in the ezetimibe/simvastatin group and 22 in the placebo group (hazard ratio 0.55, 95% confidence interval 0.27 to 1.11), indicating no significant difference between the treatment groups. During follow-up, 43 patients assigned to ezetimibe/simvastatin and 33 assigned to placebo died (hazard ratio 1.29, 95% confidence interval 0.82 to 2.03). In conclusion, in this registry-based observational follow-up study of the original SEAS study patient population, treatment with ezetimibe/simvastatin was not associated with an increased risk for cancer or mortality in the 21-month period after the completion of the original SEAS study.
|
|
