458 research outputs found
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
A new strategy for enhancing imputation quality of rare variants from next-generation sequencing data via combining SNP and exome chip data
Background: Rare variants have gathered increasing attention as a possible alternative source of missing heritability. Since next generation sequencing technology is not yet cost-effective for large-scale genomic studies, a widely used alternative approach is imputation. However, the imputation approach may be limited by the low accuracy of the imputed rare variants. To improve imputation accuracy of rare variants, various approaches have been suggested, including increasing the sample size of the reference panel, using sequencing data from study-specific samples (i.e., specific populations), and using local reference panels by genotyping or sequencing a subset of study samples. While these approaches mainly utilize reference panels, imputation accuracy of rare variants can also be increased by using exome chips containing rare variants. The exome chip contains 250 K rare variants selected from the discovered variants of about 12,000 sequenced samples. If exome chip data are available for previously genotyped samples, the combined approach using a genotype panel of merged data, including exome chips and SNP chips, should increase the imputation accuracy of rare variants. Results: In this study, we describe a combined imputation which uses both exome chip and SNP chip data simultaneously as a genotype panel. The effectiveness and performance of the combined approach was demonstrated using a reference panel of 848 samples constructed using exome sequencing data from the T2D-GENES consortium and 5,349 sample genotype panels consisting of an exome chip and SNP chip. As a result, the combined approach increased imputation quality up to 11 %, and genomic coverage for rare variants up to 117.7 % (MAF < 1 %), compared to imputation using the SNP chip alone. Also, we investigated the systematic effect of reference panels on imputation quality using five reference panels and three genotype panels. The best performing approach was the combination of the study specific reference panel and the genotype panel of combined data. Conclusions: Our study demonstrates that combined datasets, including SNP chips and exome chips, enhances both the imputation quality and genomic coverage of rare variants
Better lactate clearance associated with good neurologic outcome in survivors who treated with therapeutic hypothermia after out-of-hospital cardiac arrest
The adverse effect of emergency department crowding on compliance with the resuscitation bundle in the management of severe sepsis and septic shock
INTRODUCTION: The aim of this study is to evaluate the effects of emergency department (ED) crowding on the implementation of tasks in the early resuscitation bundle during acute care of patients with severe sepsis and septic shock, as recommended by the Surviving Sepsis Campaign guidelines. METHODS: We analyzed the sepsis registry from August 2008 to March 2012 for patients presenting to an ED of a tertiary urban hospital and meeting the criteria for severe sepsis or septic shock. The ED occupancy rate, which was defined as the total number of patients in the ED divided by the total number of ED beds, was used for measuring the degree of ED crowding. It was categorized into three groups (low; intermediate; high crowding). The primary endpoint was the overall compliance with the entire resuscitation bundle. RESULTS: A total of 770 patients were enrolled. Of the eligible patients, 276 patients were assigned to the low crowding group, 250 patients to the intermediate crowding group, and 244 patients to the high crowding group (ED occupancy rate: ≤ 115; 116–149; ≥ 150%). There was significant difference in compliance rates among the three groups (31.9% in the low crowding group, 24.4% in the intermediate crowding group, and 16.4% in the high crowding group, P < 0.001). In a multivariate model, the high crowding group had a significant association with lower compliance (adjusted odds ratio (OR), 0.44; 95% confidence interval (CI), 0.26 to 0.76; P = 0.003). When the ED occupancy rate was included as a continuous variable in the model, it had also a negative correlation with the overall compliance (OR of 10% increase of the ED occupancy rate, 0.90; 95% CI, 0.84 to 0.96, P = 0.002). CONCLUSIONS: ED crowding was significantly associated with lower compliance with the entire resuscitation bundle and decreased likelihood of the timely implementation of the bundle elements
Ketamine use for endotracheal intubation in severe sepsis and septic shock
Objective. We conducted this study to evaluate the clinical outcomes of patients with severe sepsis and septic shock who were treated with ketamine for endotracheal intubation.
Methods. A single-center, retrospective study was carried out to compare the outcomes of patients with severe sepsis and septic shock who received a ketamine or non-ketamine agent for rapid sequence
intubation (RSI). We analyzed the sepsis registry for adult patients who presented to the emergency department (ED), met the criteria for severe sepsis or septic shock, and underwent endotracheal intubation
between August 2008 and March 2014. Te primary outcome was 28-day mortality. We performed a multivariable logistic regression analysis to assess the association between ketamine use for intubation and
28-day mortality.
Results. In all, 170 patients were intubated
during the study period. Of the eligible
patients, 95 received ketamine and 75 received a non-ketamine agent. Te 28-day mortality of the ketamine group was not
signifcantly diferent from that of the nonketamine group (38% vs. 40%, respectively,P=0.78). Te unadjusted odds ratio (OR)
of ketamine use for 28-day mortality was 0.92 (95% CI: 0.49–1.70, P=0.78). Te association remained insignifcant afer adjusting for age, gender, malignancy, initial lactate level on ED admission, time to frst
antibiotic administration, Acute Physiology and Chronic Health Evaluation II score on admission day, and propensity score regarding ketamine use (adjusted OR: 1.09; 95% confdence interval [CI]: 0.49–2.40;P=0.84). Initial serum lactate on ED admission was the only signifcant predictive factor of 28-day mortality (adjusted OR:
1.23; 95% CI: 1.10–1.38; P<0.01). Conclusions. For patients with severe sepsis and septic shock who were intubated using RSI, we found no signifcant diference in 28-day mortality between those who received ketamine as a sedative agent and those who received alternative sedatives
Simultaneous Activation of Complement and Coagulation by MBL-Associated Serine Protease 2
The complement system is an important immune mechanism mediating both recognition and elimination of foreign bodies. The lectin pathway is one pathway of three by which the complement system is activated. The characteristic protease of this pathway is Mannan-binding lectin (MBL)-associated serine protease 2 (MASP2), which cleaves complement proteins C2 and C4. We present a novel and alternative role of MASP2 in the innate immune system. We have shown that MASP2 is capable of promoting fibrinogen turnover by cleavage of prothrombin, generating thrombin. By using a truncated active form of MASP2 as well as full-length MASP2 in complex with MBL, we have shown that the thrombin generated is active and can cleave both factor XIII and fibrinogen, forming cross-linked fibrin. To explore the biological significance of these findings we showed that fibrin was covalently bound on a bacterial surface to which MBL/MASP2 complexes were bound. These findings suggest that, as has been proposed for invertebrates, limited clotting may contribute to the innate immune response
Effect of typhoons on the Korean national emergency medical service system
Objective While the effect of typhoons on emergency medicine has been evaluated, data are scarce on their effects on the emergency medical service (EMS). This study evaluated the effect of typhoons on EMS patients and performance. Methods The study period was January 2010 to December 2012. Meteorological data regarding typhoons were provided by the Korean Meteorological Administration. EMS data were retrieved from the EMS database of the national emergency management agency. The database includes ambulance run sheets, which contain clinical and operational data. In this case-crossover study, the cases and controls were EMS calls on the day of typhoon warnings and calls one week prior to the typhoon warnings, respectively. Results During the study period, 11 typhoons affected Korea. A total of 14,521 cases were selected for analysis. Overall, there were no obvious differences between the case and control groups. However, there were statistically significant differences in age, place, and time requests. There were fewer patients between 0 and 15 years of age (P=0.01) and more unconscious patients (P=0.01) in the case group. The EMS operational performance, as measured by the times elapsed between call to start, call to field, and call to hospital did not differ significantly. There was also no significant difference in the time from hospital arrival between the cases (28.67, standard deviation 16.37) and controls (28.97, standard deviation 28.91) (P=0.39). Conclusion Typhoons did not significantly affect the EMS system in this study. Further study is necessary to understand the reasons for this finding
Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter
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