35 research outputs found
Effect of Finite Granularity of Detectors on Anisotropy Coefficients
The coefficients that describe the anisotropy in the azimuthal distribution
of particles are lower when the particles are recorded in a detector with
finite granularity and measures only hits. This arises due to loss of
information because of multiple hits in any channel. The magnitude of this loss
of signal depends both on the occupancy and on the value of the coefficient.
These correction factors are obtained for analysis methods differing in detail,
and are found to be different.Comment: 11 pages including 2 figure
Relevance of baseline hard proton-proton spectra for high-energy nucleus-nucleus physics
We discuss three different cases of hard inclusive spectra in proton-proton
collisions: high single hadron production at 20 GeV and
at = 62.4 GeV, and direct photon production at = 200 GeV;
with regard to their relevance for the search of Quark Gluon Plasma signals in
A+A collisions at SPS and RHIC energies.Comment: Proceeds. Hot Quarks 2004 Int. Workshop on the Physics of
Ultrarelativistic Nucleus-Nucleus Collisions. 26 pages. 26 figs. [minor
corrs., refs. added
Recent results from Pb-Au collisions at 158 GeV/c per nucleon obtained with the CERES spectrometer
During the 1996 lead run time, CERES has accumulated 42 million events,
corresponding to a factor of 5 more statistics than in 1995 and 2.5 million
events of a special photon-run. We report on the results of the low-mass
ee-pair analysis. Since the most critical item is the poor
signal-to-background ratio we also discuss the understanding of this
background, in absolute terms, with the help of a detailed Monte Carlo
simulation. We show preliminary results of the photon analysis and summarize
the results of the hadron analysis preliminarily reported on already at QM'97Comment: 10 pages, 9 figures, Proceedings of the XIV Int. Conf. on
Nucleus-Nucleus Collisions,Quark Matter 99, Torino, Italy, May 10 - 15, 199
Phellinus linteus suppresses growth, angiogenesis and invasive behaviour of breast cancer cells through the inhibition of AKT signalling
The antitumour activity of a medicinal mushroom Phellinus linteus (PL), through the stimulation of immune system or the induction of apoptosis, has been recently described. However, the molecular mechanisms responsible for the inhibition of invasive behaviour of cancer cells remain to be addressed. In the present study, we demonstrate that PL inhibits proliferation (anchorage-dependent growth) as well as colony formation (anchorage-independent growth) of highly invasive human breast cancer cells. The growth inhibition of MDA-MB-231 cells is mediated by the cell cycle arrest at S phase through the upregulation of p27Kip1 expression. Phellinus linteus also suppressed invasive behaviour of MDA-MB-231 cells by the inhibition of cell adhesion, cell migration and cell invasion through the suppression of secretion of urokinase-plasminogen activator from breast cancer cells. In addition, PL markedly inhibited the early event in angiogenesis, capillary morphogenesis of the human aortic endothelial cells, through the downregulation of secretion of vascular endothelial growth factor from MDA-MB-231 cells. These effects are mediated by the inhibition of serine-threonine kinase AKT signalling, because PL suppressed phosphorylation of AKT at Thr308 and Ser473 in breast cancer cells. Taken together, our study suggests potential therapeutic effect of PL against invasive breast cancer
NAHA, a Novel Hydroxamic Acid-Derivative, Inhibits Growth and Angiogenesis of Breast Cancer In Vitro and In Vivo
BACKGROUND: We have recently synthesized novel N-alkylated amino acid-derived hydroxamate, 2-[Benzyl-(2-nitro-benzenesulfonyl)-amino]-N-hydroxy-3-methyl-N-propyl-butyramide (NAHA). Here, we evaluate the anticancer activity of NAHA against highly invasive human breast cancer cells MDA-MB-231 in vitro and in vivo. METHODOLOGY/PRINCIPAL FINDINGS: Cell growth was evaluated by MTT and soft agar assays. Protein expression was determined by DNA microarray and Western blot analysis. Metastatic potential was evaluated by cell adhesion, migration, invasion, capillary morphogenesis, and ELISA assays. The anticancer activity in vivo was evaluated in mouse xenograft model. NAHA inhibited proliferation and colony formation of MDA-MB-231 cells together with the down-regulation of expression of Cdk2 and CDC20 proteins. NAHA inhibited cell adhesion, migration, and invasion through the suppression of secretion of uPA. NAHA suppressed secretion of VEGF from MDA-MB-231 cells and inhibited capillary morphogenesis of human aortic endothelial cells (HAECs). Finally, NAHA at 50 mg/kg was not toxic and decreased tumor volume and tumor weight in vivo. This suppression of tumor growth was associated with the inhibition of mitotic figures and induction of apoptosis, and the reduction of CD31 and VEGF positive cells in tumors. CONCLUSION: NAHA could be a novel promising compound for the development of new drugs for the therapy of invasive breast cancers
Enhanced production of low-mass electron-positron pairs in 40-AGeV Pb-Au collisions at the CERN SPS
We report on first measurements of low-mass electron pairs in Pb-Au collisions at the lower SPS beam energy of 40 AGeV. The pair yield integrated over the range of invariant masses 0.2 e+ e- annihilation with a modified rho-propagator. They may be linked to chiral symmetry restoration and support the notion that the in-medium modifications of the rho are more driven by baryon density than by temperature.We report on first measurements of low-mass electron pairs in Pb-Au collisions at the lower SPS beam energy of 40 AGeV. The pair yield integrated over the range of invariant masses 0.2<m<1 GeV/c^2 is enhanced by a factor of 5.1+-1.3(stat)+-1.0/1.5(syst data/decays) over the expectation from neutral meson decays, more than previously observed at the higher energy of 158 AGeV. The results are discussed with reference to model calculations based on pi+ pi- -> e+ e- annihilation with a modified rho-propagator. They may be linked to chiral symmetry restoration and support the notion that the in-medium modifications of the rho are more driven by baryon density than by temperature
Early collective expansion: Relativistic hydrodynamics and the transport properties of QCD matter
Relativistic hydrodynamics for ideal and viscous fluids is discussed as a
tool to describe relativistic heavy-ion collisions and to extract transport
properties of the quark-gluon plasma from experimentally measured hadron
momentum spectra.Comment: Review article, 54 pages, 25 figure
Simulations of Denial of Service Attacks in Quantum Key Distribution Networks
A QKD network can be considered an add-on
technology to a standard communication network that provides
IT-secure cryptographic keys as a service. As a result, security
challenges resulting in the suspension of functional work must
be addressed. This study analyzes a Denial of Service (DoS)
attack on the Key Management System (KMS), one of the
critical components of the QKD network in charge of key
management and key provisioning to authorized consumers.
Through simulation methods performed in the QKDNetSim, we
show that legitimate customers experience significantly worse
service during an excessive DoS attack on KMS
Wpływ suszy hydrologicznej na parametry ilościowe i jakościowe wód powierzchniowych i podziemnych w zlewni Torysy, wschodnia Słowacja
Surface water and groundwater quantitative and qualitative parameters depend on many factors, among which the climatic conditions and human influence play an important role. Hydrological drought affects first the surface water and with a certain time-lag also the groundwater. Human influence affects both the quantitative and qualitative properties. Hydrological drought in surface water and groundwater in the area of the upper Torysa River catchment was derived using the threshold level method for streamflow and baseflow values. Baseflow values were calculated using the local minimum method. In the end, number of surface water and groundwater drought periods was compared stressing the length of the drought period and time shift between the starting dates. Changes in chemical composition of surface and groundwater during drought periods were studied and analysed.Parametry ilościowe i jakościowe wód powierzchniowych i podziemnych zależą od wielu czynników, spośród których ważną rolę odgrywają warunki klimatyczne i działalność człowieka. Susza meteorologiczna początkowo oddziaływuje na wody powierzchniowe, a po pewnym czasie również na wody podziemne. Działalność człowieka wpływa zarówno na jakościowe, jak i ilościowe cechy wód. Susza hydrologiczna w wodach powierzchniowych i podziemnych w zlewni górnej Torysy została określona metodą poziomu progowego dla przepływu bazowego i przepływu całkowitego. Wartości przepływu bazowego obliczono metodą lokalnych minimów. Ostatecznie, liczba okresów suszy dla wód powierzchniowych i podziemnych została wyznaczona przez kompresję okresów suszy w ruchomych interwałach czasowych. Przeprowadzone analizy i prace studialne wykazały zmiany składu chemicznego wód w okresach suszy