Monitoring a wandering mean with an np chart

Este artigo considera um gráfico np x proposto por Wu et al. (2009) para controle de média de processo como uma alternativa ao uso do gráfico de. O que distingue do gráfico de controle np x é o fato das unidades amostrais serem classificadas como unidades de primeiro ou de segunda classe de acordo com seus limites discriminantes. O gráfico tradicional np é um caso particular do gráfico np x quando os limites discriminantes coincidem com os limites de especificação e unidade de primeira (segunda) classe é um item conforme (não conforme). Estendendo o trabalho de Reynolds Junior, Arnold e Baik (1996), consideramos que a média de processo oscila mesmo na ausência de alguma causa especial. As propriedades de Cadeia de Markov foram adotadas para avaliar o desempenho do gráfico np x no monitoramento de média de processos que oscila. de modo geral, o gráfico np x requer amostras duas vezes maior para superar desempenho do gráfico (enquanto que o gráfico tradicional np necessita tamanho de amostras cinco ou seis vezes maior).

Antiulcer activity and subacute toxicity of trans-dehydrocrotonin from Croton cajucara

The antiulcerogenic activity of trans-dehydrocrotonin (DHC), a nor-clerodane diterpene isolated from Croton cajucara Benth. ( Euphorbiaceae), and its subacute ( 35 days) toxicity were studied in mice and rats, respectively. For the antiulcerogenic tests, models of gastric ulcers induced in mice by ethanol/HCl or stress were used. In both models, an oral dose of DHC ( 100 mg/kg) significantly reduced (P< 0.01) the formation of gastric lesions. DHC was also tested for its ability to scavenge free radicals, but no such action was observed in rat liver mitochondria. To assess the subacute toxicity, rats were treated orally with DHC (25, 50 and 100 mg/kg) for 5 weeks. A significant increase in liver weight was observed in male and female rats at highest doses, whereas a significant reduction in plasma alkaline phosphatase and cholesterol levels and an increase in gamma glutamyl transpeptidase were observed only at the highest dose ( 100 mg/kg) in female rats. DHC caused histopathological alterations in the liver that included a turbid tumefaction, microvacuolar degeneration and nuclear alterations. Despite the beneficial antiulcerogenic activity of DHC, our results suggest that the long-term use of this compound may induce liver damage.

Frequent p53 mutations and occasional loss of chromosome 4 in invasive bladder carcinoma induced by N-butyl-N-(4-hydroxybutil)nitrosamine in B6D2F1 mice

B6D2F1 mice (45/group) were treated with N-butyl-N-(4- hydroxybutyl)nitrosamine (BBN) or uracil as follows: Group 1 received 0.05% BBN in drinking water for the entire experiment, Group 2 received 5 mg of BBN by gastric gavage in 0.1 mL of 20% ethanol twice per week for 10 wk, Group 3 received a 2.5% uracil-containing diet for the entire experiment, and Group 4 was controls (received 0.1 mL of 20% ethanol by gavage twice per week for 10 wk). The surviving mice in Group 1 were killed after week 26 and those in the other groups after week 30. By week 15, three of 11 Group 1 and one of 15 Group 2 mice had bladder carcinoma. By 26 and 30 wk, respectively, invasive carcinomas were observed in 33 of 34 and six of 21 mice in Groups 1 and 2 and renal pelvic carcinomas in 11 of 34 and three of 21 mice in Groups 1 and 2. Four of 19 uracil-treated mice had bladder nodular hyperplasia. By polymerase chain reaction-single-strand conformation polymorphism and sequence analyses, 16 of 20 and two of five bladder carcinomas from Groups 1 and 2, respectively, showed mutations in the p53 gene. Ha-ras mutation was present in one case. Loss of heterozygosity analysis with simple-sequence length polymorphism markers for chromosome 4 showed that 10 of 21, two of 15, and nine of 13 mice in Groups 1-3, respectively, had heterozygous or homozygous deletions. B6D2F1 mice are therefore susceptible to the urothelial carcinogenic effects of BBN and develop frequent p53 mutations and chromosome 4 deletions. Chromosome 4 deletions were also seen with uracil.

Comparison of uroplakin expression during urothelial carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)nitrosamine in rats and mice

The expression of uroplakins, the tissue-specific and differentiation- dependent membrane proteins of the urothelium, was analyzed immunohistochemically in N butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-treated rats and mice during bladder carcinogenesis. Male Fischer 344 rats were treated with 0.05% BBN in the drinking water for 10 wk and were cuthanatized at week 20 of the experiment. BBN was administered to male B6D2F1 mice; it was either provided at a rate of 0.05% in the drinking water (for 26 wk) or 5 mg BBN was administered by intragastric gavage twice weekly for 10 wk, followed by 20 wk without treatment. In rats, BBN-induced, noninvasive, low grade, papillary, transitional cell carcinoma (TCC) showed decreased uroplakin-staining of cells lining the lumen but showed increased expression in some nonluminal cells. In mice, nonpapillary, high-grade dysplasia, carcinoma in situ, and invasive carcinoma were induced. There was a marked decrease in the number of uroplakin-positive cells lining the lumen and in nonluminal cells. This occurred in normal-appearing urothelium in BBN-treated mice and in dysplasic urothelium, in carcinoma in situ, and in invasive TCC. The percentage of uroplakin-positive nonluminal cells was higher in control mice than in rats, but it was lower in the mouse than in the rat after BBN treatment. Uroplakin expression was disorderly and focal in BBN-treated urothelium in both species. These results indicate that BBN treatment changed the expression of uroplakins during bladder carcinogenesis, with differences in rats and mice being related to degree of tumor differentiation.

Measurement of the muon stopping power in lead tungstate

A large sample of cosmic ray events collected by the CMS detector is exploited to measure the specific energy loss of muons in the lead tungstate (PbWO4) of the electromagnetic calorimeter. The measurement spans a momentum range from 5 GeV/c to 1 TeV/c. The results are consistent with the expectations over the entire range. The calorimeter energy scale, set with 120 GeV/c electrons, is validated down to the sub-GeV region using energy deposits, of order 100 MeV, associated with low-momentum muons. The muon critical energy in PbWO4 is measured to be 160+5 -68 GeV, in agreement with expectations. This is the first experimental determination of muon critical energy. © 2010 IOP Publishing Ltd and SISSA.

Commissioning of the CMS experiment and the cosmic run at four tesla

The CMS Collaboration conducted a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to complete the commissioning of the experiment for extended operation. The operational lessons resulting from this exercise were addressed in the subsequent shutdown to better prepare CMS for LHC beams in 2009. The cosmic data collected have been invaluable to study the performance of the detectors, to commission the alignment and calibration techniques, and to make several cosmic ray measurements. The experimental setup, conditions, and principal achievements from this data-taking exercise are described along with a review of the preceding integration activities. © 2010 IOP Publishing Ltd and SISSA.

Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams

The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected. © 2010 IOP Publishing Ltd and SISSA.

Performance of the CMS drift-tube chamber local trigger with cosmic rays

The performance of the Local Trigger based on the drift-tube system of the CMS experiment has been studied using muons from cosmic ray events collected during the commissioning of the detector in 2008. The properties of the system are extensively tested and compared with the simulation. The effect of the random arrival time of the cosmic rays on the trigger performance is reported, and the results are compared with the design expectations for proton-proton collisions and with previous measurements obtained with muon beams. © 2010 IOP Publishing Ltd and SISSA.

Fine synchronization of the CMS muon drift-tube local trigger using cosmic rays

The CMS experiment uses self-triggering arrays of drift tubes in the barrel muon trigger to perform the identification of the correct bunch crossing. The identification is unique only if the trigger chain is correctly synchronized. In this paper, the synchronization performed during an extended cosmic ray run is described and the results are reported. The random arrival time of cosmic ray muons allowed several synchronization aspects to be studied and a simple method for the fine synchronization of the Drift Tube Local Trigger at LHC to be developed. © 2010 IOP Publishing Ltd and SISSA.

Commissioning of the CMS High-Level Trigger with cosmic rays

The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole. © 2010 IOP Publishing Ltd and SISSA.

CMS data processing workflows during an extended cosmic ray run

The CMS Collaboration conducted a month-long data taking exercise, the Cosmic Run At Four Tesla, during October-November 2008, with the goal of commissioning the experiment for extended operation. With all installed detector systems participating, CMS recorded 270 million cosmic ray events with the solenoid at a magnetic field strength of 3.8 T. This paper describes the data flow from the detector through the various online and offline computing systems, as well as the workflows used for recording the data, for aligning and calibrating the detector, and for analysis of the data. © 2010 IOP Publishing Ltd and SISSA.

Commissioning and performance of the CMS pixel tracker with cosmic ray muons

The pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns. © 2010 IOP Publishing Ltd and SISSA.

Alignment of the CMS silicon tracker during commissioning with cosmic rays

The CMS silicon tracker, consisting of 1440 silicon pixel and 15 148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to an average precision of 3-4 microns RMS in the barrel and 3-14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several studies, including laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution, and are compared with predictions obtained from simulation. Correlated systematic effects have been investigated. The track parameter resolutions obtained with this alignment are close to the design performance. © 2010 IOP Publishing Ltd and SISSA.

Performance and operation of the CMS electromagnetic calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75 848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented. © 2010 IOP Publishing Ltd and SISSA.