121 research outputs found
A batch-service queueing model with a discrete batch Markovian arrival process
Queueing systems with batch service have been investigated extensively during the past decades. However, nearly all the studied models share the common feature that an uncorrelated arrival process is considered, which is unrealistic in several real-life situations. In this paper, we study a discrete-time queueing model, with a server that only initiates service when the amount of customers in system (system content) reaches or exceeds a threshold. Correlation is taken into account by assuming a discrete batch Markovian arrival process (D-BMAP), i.e. the distribution of the number of customer arrivals per slot depends on a background state which is determined by a first-order Markov chain. We deduce the probability generating function of the system content at random slot marks and we examine the influence of correlation in the arrival process on the behavior of the system. We show that correlation merely has a small impact on the threshold that minimizes the mean system content. In addition, we demonstrate that correlation might have a significant influence on the system content and therefore has to be included in the model
Measurement of the Decay Asymmetry Parameters in and
We have measured the weak decay asymmetry parameters (\aLC ) for two \LC\
decay modes. Our measurements are \aLC = -0.94^{+0.21+0.12}_{-0.06-0.06} for
the decay mode and \aLC = -0.45\pm 0.31 \pm
0.06 for the decay mode . By combining these
measurements with the previously measured decay rates, we have extracted the
parity-violating and parity-conserving amplitudes. These amplitudes are used to
test models of nonleptonic charmed baryon decay.Comment: 11 pages including the figures. Uses REVTEX and psfig macros. Figures
as uuencoded postscript. Also available as
http://w4.lns.cornell.edu/public/CLNS/1995/CLNS95-1319.p
Production and Decay of D_1(2420)^0 and D_2^*(2460)^0
We have investigated and final states and
observed the two established charmed mesons, the with mass
MeV/c and width MeV/c and
the with mass MeV/c and width
MeV/c. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the doublet predicted
by HQET. We also obtain constraints on {\footnotesize } as a function of the cosine of the relative phase of the two
amplitudes in the decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by
sending mail to: [email protected]
Measurement of the branching fraction for
We have studied the leptonic decay of the resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find . The result is consistent with
expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS
94/1297, CLEO 94-20 (submitted to Physics Letters B
Observation of the Charmed Baryon Decays to , , and
We have observed two new decay modes of the charmed baryon into
and using data collected with the
CLEO II detector. We also present the first measurement of the branching
fraction for the previously observed decay mode . The branching fractions for these three modes relative to
are measured to be , , and , respectively.Comment: 12 page uuencoded postscript file, postscript file also available
through http://w4.lns.cornell.edu/public/CLN
Proteogenomic integration reveals therapeutic targets in breast cancer xenografts
Recent advances in mass spectrometry (MS) have enabled extensive analysis of cancer proteomes. Here, we employed quantitative proteomics to profile protein expression across 24 breast cancer patient-derived xenograft (PDX) models. Integrated proteogenomic analysis shows positive correlation between expression measurements from transcriptomic and proteomic analyses; further, gene expression-based intrinsic subtypes are largely re-capitulated using non-stromal protein markers. Proteogenomic analysis also validates a number of predicted genomic targets in multiple receptor tyrosine kinases. However, several protein/phosphoprotein events such as overexpression of AKT proteins and ARAF, BRAF, HSP90AB1 phosphosites are not readily explainable by genomic analysis, suggesting that druggable translational and/or post-translational regulatory events may be uniquely diagnosed by MS. Drug treatment experiments targeting HER2 and components of the PI3K pathway supported proteogenomic response predictions in seven xenograft models. Our study demonstrates that MS-based proteomics can identify therapeutic targets and highlights the potential of PDX drug response evaluation to annotate MS-based pathway activities
Metabolitos de Aspergillus fumigatus endofítico e seu efeito in vitro contra o agente causal da tuberculose
Tuberculosis (TB) remains one of the most deadly communicable infectious diseases, causing 1.4 million deaths in 2015 worldwide due to many conditions, including the inadequate treatment and the emergence of multidrug-resistant strains of the causal agent, Mycobacterium tuberculosis. Therefore, drugs developed from natural sources, as microorganisms and plant extracts, are a frequent target for the research and discovery of antimicrobial compounds. The current study started the characterization of compounds produced by an Aspergillus fumigatus isolated from copaíba (Copaifera multijuga) that efficiently inhibits M. tuberculosis by releasing the compounds into the fermentation broth under specific culture conditions. A preliminary assay was carried out with a correlate species, M. smegmatis, aiming to detect an antimicrobial effect related to A. fumigatus fermentation broth. The direct use of this substrate in antibiosis assays againstM. tuberculosis H37Rv strain (ATCC 27294) allowed the detection of antimicrobial activity with a minimal inhibitory concentration of 256 μg mL-1, demonstrating that purification processes developed by the Biotage Flash Chromatography System are robust and reliable techniques for purification of compounds from natural sources. Also, this chromatographic system can be used in combination with specific biochemical tests, improving the search for reliable results. We conclude that this fraction can express a broad action range, inhibiting both Mycobacterium species used as target organisms.A tuberculose continua a ser uma das doenças infecciosas transmissíveis mais mortais, causando 1,4 milhão de mortes em 2015 em todo o mundo devido a vários fatores, incluindo o tratamento inadequado e o surgimento de cepas multirresistentes do agente causal, Mycobacterium tuberculosis. Portanto, as drogas desenvolvidas a partir de fontes naturais, como micro-organismos e extratos de plantas, são um alvo freqüente para a pesquisa e descoberta de compostos antimicrobianos. O presente estudo foi um ponto de partida para caracterizar compostos produzidos por um Aspergillus fumigatus isolado de copaíba (Copaifera multijuga) que inibe eficientemente M. tuberculosis, liberando os compostos no caldo de fermentação em condições de cultura específicas. Realizou-se um ensaio preliminar com uma espécie correlata, M. smegmatis, com o objetivo de detectar um efeito antimicrobiano relacionado ao caldo de fermentação de A. fumigatus. O uso direto deste substrato em ensaios de antibiose contra a estirpe H37Rv de M. tuberculosis (ATCC 27294) permitiu a detecção de atividade antimicrobiana com uma concentração inibitória mínima de 256 μg mL-1, demonstrando que os processos de purificação desenvolvidos pelo Biotage Flash Chromatography System são técnicas robustas e confiáveis para purificar compostos de fontes naturais. Além disso, este sistema cromatográfico pode ser usado em combinação com testes bioquímicos específicos, melhorando a busca de resultados confiáveis. Concluímos que esta fração pode expressar uma ampla gama de ação, inibindo ambas as espécies de Mycobacterium utilizadas como organismos-alvo
Search for the Xb and other hidden-beauty states in the π+π−ϒ(1S) channel at ATLAS
This Letter presents a search for a hidden-beauty counterpart of the X(3872) in the mass ranges of 10.05–10.31 GeV and 10.40–11.00 GeV, in the channel Xb→π+π−ϒ(1S)(→μ+μ−), using 16.2 fb−1 of pp collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the Xb cross section and branching fraction, relative to those of the ϒ(2S), at the 95% confidence level using the CLS approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the ϒ(13DJ), , and states also reveal no significant signals
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