834 research outputs found
The Akt inhibitor KP372-1 suppresses Akt activity and cell proliferation and induces apoptosis in thyroid cancer cells
The phosphatidylinositol 3Ⲡkinase (PI3K)/phosphatase and tensin homologue deleted on chromosome ten/Akt pathway, which is a critical regulator of cell proliferation and survival, is mutated or activated in a wide variety of cancers. Akt appears to be a key central node in this pathway and thus is an attractive target for targeted molecular therapy. We demonstrated that Akt is highly phosphorylated in thyroid cancer cell lines and human thyroid cancer specimens, and hypothesised that KP372-1, an Akt inhibitor, would block signalling through the PI3K pathway and inhibit cell proliferation while inducing apoptosis of thyroid cancer cells. KP372-1 blocked signalling downstream of Akt in thyroid tumour cells, leading to inhibition of cell proliferation and increased apoptosis. As thyroid cancer consistently expresses phosphorylated Akt and KP372-1 effectively blocks Akt signalling, further preclinical evaluation of this compound for treatment of thyroid cancer is warranted
Search for a New Heavy Gauge Boson Wprime with Electron + missing ET Event Signature in ppbar collisions at sqrt(s)=1.96 TeV
We present a search for a new heavy charged vector boson decaying
to an electron-neutrino pair in collisions at a center-of-mass
energy of 1.96\unit{TeV}. The data were collected with the CDF II detector
and correspond to an integrated luminosity of 5.3\unit{fb}^{-1}. No
significant excess above the standard model expectation is observed and we set
upper limits on . Assuming standard
model couplings to fermions and the neutrino from the boson decay to
be light, we exclude a boson with mass less than
1.12\unit{TeV/}c^2 at the 95\unit{%} confidence level.Comment: 7 pages, 2 figures Submitted to PR
Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay
We reconstruct the rare decays , , and in a data sample
corresponding to collected in collisions at
by the CDF II detector at the Fermilab Tevatron
Collider. Using and decays we report the branching ratios. In addition, we report
the measurement of the differential branching ratio and the muon
forward-backward asymmetry in the and decay modes, and the
longitudinal polarization in the decay mode with respect to the squared
dimuon mass. These are consistent with the theoretical prediction from the
standard model, and most recent determinations from other experiments and of
comparable accuracy. We also report the first observation of the {\mathcal{B}}(B^0_s \to
\phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}27 \pm 6B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let
Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons
We report measurements of the resonance properties of Lambda_c(2595)+ and
Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as
Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+
pi+/- final states. These measurements are performed using data corresponding
to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV,
collected with the CDF II detector at the Fermilab Tevatron. Exploiting the
largest available charmed baryon sample, we measure masses and decay widths
with uncertainties comparable to the world averages for Sigma_c states, and
significantly smaller uncertainties than the world averages for excited
Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17
pages, 15 figure
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
Fluctuations in measured radioactive decay rates inside a modified Faraday cage: Correlations with space weather
[EN] For several years, reports have been published about fluctuations in measured radioactive decay time-series and in some instances linked to astrophysical as well as classical environmental influences. Anomalous behaviors of radioactive decay measurement and measurement of capacitance inside and outside a modified Faraday cage were documented by our group in previous work. In the present report, we present an in-depth analysis of our measurement with regard to possible correlations with space weather, i.e. the geomagnetic activity (GMA) and cosmic-ray activity (CRA). Our analysis revealed that the decay and capacitance time-series are statistically significantly correlated with GMA and CRA when specific conditions are met. The conditions are explained in detail and an outlook is given on how to further investigate this important finding. Our discovery is relevant for all researchers investigating radioactive decay measurements since they point out that the space weather condition during the measurement is relevant for partially explaining the observed variability.This work has been partially financed by: grant no. 20170764 (Equipos de deteccion, regulacion e informacion en el sector de los sistemas inteligentes de transporte (ITS). Nuevos modelos y ensayos de compatibilidad y verificacion de funcionamiento) (Spain), by grant no. RTI2018-102256-B-I00 (Spain), by the Generalitat Valenciana (Spain) under project Bioingenieria de las Radiaciones Ionizantes. Biorad (PROMETEO/2018/035) and the project MEMO RADION (IDIFEDER/2018/038) co-financed by the Programa Operativo del Fondo Social Europeo 2014-2020", and by grant No.075-00845-20-01 (Russia).MiliĂĄn-SĂĄnchez, V.; Scholkmann, F.; FernĂĄndez De CĂłrdoba, P.; MocholĂ Salcedo, A.; MocholĂ-Belenguer, F.; Iglesias-MartĂnez, ME.; Castro-Palacio, JC.... (2020). Fluctuations in measured radioactive decay rates inside a modified Faraday cage: Correlations with space weather. Scientific Reports. 10(1):1-12. https://doi.org/10.1038/s41598-020-64497-0S112101MiliĂĄn-SĂĄnchez, V., MocholĂ-Salcedo, A., MiliĂĄn, C., Kolombet, V. A. & VerdĂş, G. Anomalous effects on radiation detectors and capacitance measurements inside a modified Faraday cage. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 828, 210â228 (2016).G. F. Knoll Radiation Detection and Measurement, 4th Edition. (Wiley, 2010).Jenkins, J. H., Mundy, D. W. & Fischbach, E. Analysis of environmental influences in nuclear half-life measurements exhibiting time-dependent decay rates. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 620, 332â342 (2010).Jenkins, J. H. et al. Additional experimental evidence for a solar influence on nuclear decay rates. Astroparticle Physics 37, 81â88 (2012).Falkenberg, E. D. Radioactive Decay Caused by Neutrinos? Apeiron 8, 32â45 (2001).A. G. Parkhomov Influence of Relic Neutrinos on Beta Radioactivity. arXiv:1010.1591v1 [physics.gen-ph], (2010).P. A. Sturrock, E. Fischbach, A. G. Parkhamov, J. D. Scargle, G. Steinitz, Concerning the variability of beta-decay measurements. arXiv:1510.05996 [nucl-ex], (2015).Baurov, Y. A. et al. Experimental Investigations of Changes in β-Decay if 60Co and 137Cs. Modern Physics Letters A 16, 2089â2101 (2001).Baurov, Y. A. Research of Global Anisotropy of Physical Space on Investigation Base of Changes in β and Îą-decay Rate of Radioactive Elements. Motion of Pulsars and Anisotropy of Cosmic Rays. American Journal of Modern Physics 2, 177â184 (2013).Baurov, Y. A., Sobolev, Y. G., Ryabov, Y. V. & Kushniruk, V. F. Experimental investigations of changes in the rate of beta decay of radioactive elements. Physics of Atomic Nuclei 70, 1825â1835 (2009).Baurov, Y. A. The anisotropic phenomenon in the β decay of radioactive elements and in other processes in nature. Bulletin of the Russian Academy of Sciences: Physics 76, 1076â1080 (2012).Baurov, Y. A., Sobolev, Y. G. & Ryabov, Y. V. New force, global anisotropy and the changes in β-decay rate of radioactive elements. American Journal of Astronomy and Astrophysics 2, 8â19 (2014).Pons, D. J., Pons, A. D. & Pons, A. J. Asymmetrical neutrino induced decay of nucleons. Applied Physics Research 7, 1â13 (2015).Pons, D. J., Pons, A. D. & Pons, A. J. Hidden Variable Theory Supports Variability in Decay Rates of Nuclides. Applied Physics Research 7, 18â29 (2015).Kossert, K. & Nähle, O. J. Long-term measurements of 36Cl to investigate potential solar influence on the decay rate. Astroparticle Physics 55, 33â36 (2014).Schrader, H. Seasonal variations of decay rate measurement data and their interpretation. Applied Radiation and Isotopes 114, 202â213 (2016).PommĂŠ, S. et al. Evidence against solar influence on nuclear decay constants. Physics Letters B 761, 281â286 (2016).Bergeson, S. D., Peatross, J. & Ware, M. J. Precision long-term measurements of beta-decay-rate ratios in a controlled environment. Physics Letters B 767, 171â176 (2017).McKnight, Q., Bergeson, S. D., Peatross, J. & Ware, M. J. 2.7 years of beta-decay-rate ratio measurements in a controlled environment. Applied Radiation and Isotopes 142, 113â119 (2018).PommĂŠ, S. et al. On decay constants and orbital distance to the Sunâpart I: alpha decay. Metrologia 54, 1â18 (2017).PommĂŠ, S. et al. On decay constants and orbital distance to the Sunâpart III: beta plus and electron capture decay. Metrologia 54, 36â50 (2017).PommĂŠ, S., Lutter, G., Marouli, M., Kossert, K. & Nähle, O. On the claim of modulations in radon decay and their association with solar rotation. Astroparticle Physics 97, 38â45 (2018).S. PommĂŠ, K. Kossert, O. Nähle On the Claim of Modulations in 36Cl Beta Decay and Their Association with Solar Rotation. Solar Physics 292 (2017).PommĂŠ, S. et al. Is decay constant? Applied Radiation and Isotopes 134, 6â12 (2018).Bellotti, E., Broggini, C., Di Carlo, G., Laubenstein, M. & Menegazzo, R. Search for time modulations in the decay constant of 40 K and 226 Ra at the underground Gran Sasso Laboratory. Physics Letters B 780, 61â65 (2018).Borrello, J. A., Wuosmaa, A. & Watts, M. Non-dependence of nuclear decay rates of 123 I and 99m Tc on Earth-Sun distance. Applied Radiation and Isotopes 132, 189â194 (2018).Sturrock, P. A., Steinitz, G., Fischbach, E., Parkhomov, A. & Scargle, J. D. Analysis of beta-decay data acquired at the Physikalisch-Technische Bundesanstalt: Evidence of a solar influence. Astroparticle Physics 84, 8â14 (2016).Stancil, D. D., Balci Yegen, S., Dickey, D. A. & Gould, C. R. Search for possible solar influences in Ra-226 decays. Results in Physics 7, 385â406 (2017).P. A. Sturrock, G. Steinitz & E. Fischbach Analysis of Ten Years of Radon-Chain Decay Measurements: Evidence of Solar Influences and Inferences Concerning Solar Internal Structure and the Role of Neutrinos. arXiv:1705.03010 [astro-ph.SR], (2017).Sturrock, P. A., Steinitz, G. & Fischbach, E. Concerning the variability of nuclear decay rates: Rebuttal of an article by Pomme et al. [1]. Astroparticle Physics 98, 9â12 (2018).PommĂŠ, S., Lutter, G., Marouli, M., Kossert, K. & Nähle, O. A reply to the rebuttal by Sturrock et al. Astroparticle Physics 107, 22â25 (2019).S. PommĂŠ, Solar influence on radon decay rates: irradiance or neutrinos? The European Physical Journal C. 79 (2019).Barnes, V. E. et al. Upper limits on perturbations of nuclear decay rates induced by reactor electron antineutrinos. Applied Radiation and Isotopes 149, 182â199 (2019).PommĂŠ, S., Stroh, H. & Van Ammel, R. The 55Fe half-life measured with a pressurised proportional counter. Applied Radiation and Isotopes 148, 27â34 (2019).Elmaghraby, E. E. Configuration Mixing in Particle Decay and Reaction. Progress in Physics 13, 150â155 (2017).Shnoll, S. E. et al. Realization of discrete states during fluctuations in macroscopic processes. Physics-Uspekhi 41, 1025â1035 (1998).Namiot, V. A. & Shnoll, S. E. On the possible mechanism of periodicity in fine structure of histograms during nuclear decay processes. Physics Letters A 359, 249â251 (2006).Panchelyuga, V. A. & Panchelyuga, M. S. Fractal dimension and histogram method: Algorithm and some preliminary results of noise-like time series analysis. Biophysics 58, 283â289 (2013).Panchelyuga, V. A. & Panchelyuga, M. S. Local fractal analysis of noise-like time series by the all-permutations method for 1â115 min periods. Complex Systems Biophysics 60, 317â330 (2015).T. A. Zenchenko, A. A. Konradov, K. I. Zenchenko In Biophotonics and Coherent Systems in Biology. chap. Chapter 18, pp. 225â233 (2005).Jenkins, J. H. & Fischbach, E. Perturbation of nuclear decay rates during the solar flare of 2006 December 13. Astroparticle Physics 31, 407â411 (2009).F. Scholkmann et al., Anomalous effects of radioactive decay rates and capacitance values measured inside a modified Faraday cage: Correlations with space weather. EPL (Europhysics Letters) 117 (2017).M. E. Iglesias-MartĂnez et al. Correlations between Background Radiation Inside a Multilayer Interleaving Structure, Geomagnetic Activity, and Cosmic Radiation: A Fourth-Order Cumulant-Based Correlation Analysis. Mathematics 8 (2020).Karinen, A. & Mursula, K. A new reconstruction of the Dst index for 1932-2002. Annales Geophysicae 23, 475â485 (2005).A. Karinen, K. Mursula Correcting the Dst index: Consequences for absolute level and correlations. Journal of Geophysical Research 111 (2006).Nakamura, T., Uwamino, Y., Ohkubo, T. & Hara, A. Altitude Variation of Cosmic-ray Neutrons. Health Physics 53, 509â517 (1987).Hendrick, L. D. & Edge, R. D. Cosmic-Ray Neutrons near the Earth. Physical Review 145, 1023â1025 (1966).Yamashita, M., Stephens, L. D. & Patterson, H. W. Cosmic-ray-produced neutrons at ground level: Neutron production rate and flux distribution. Journal of Geophysical Research 71, 3817â3834 (1966).Mohsinally, T. et al. Evidence for correlations between fluctuations in 54Mn decay rates and solar storms. Astroparticle Physics 75, 29â37 (2016).Snyder, C. W., Neugebauer, M. & Rao, U. R. The solar wind velocity and its correlation with cosmic-ray variations and with solar and geomagnetic activity. Journal of Geophysical Research 68, 6361â6370 (1963).Kharayat, H., Prasad, L., Mathpal, R., Garia, S. & Bhatt, B. Study of Cosmic Ray Intensity in Relation to the Interplanetary Magnetic Field and Geomagnetic Storms for Solar Cycle 23. Solar Physics 291, 603â611 (2016).M. Tsichla, M. Gerontidou, H. Mavromichalaki, Spectral Analysis of Solar and Geomagnetic Parameters in Relation to Cosmic-ray Intensity for the Time Period 1965âââ2018. Solar Physics 294 (2019).Singh, Y. P. Badruddin, Short- and mid-term oscillations of solar, geomagnetic activity and cosmic-ray intensity during the last two solar magnetic cycles. Planetary and Space Science 138, 1â6 (2017).B. Adhikari, N. Sapkota, P. Baruwal, N. P. Chapagain & C. R. Braga Impacts on Cosmic-Ray Intensity Observed During Geomagnetic Disturbances. Solar Physics 292 (2017).Grigoryev, V. G., Starodubtsev, S. A. & Gololobov, P. Y. Monitoring geomagnetic disturbance predictors using data of ground measurements of cosmic rays. Bulletin of the Russian Academy of Sciences: Physics 81, 200â202 (2017).W. Reich Selected Writings: An Introduction to Orgonomy. (Farrar, Straus and Cudahy, 1960).Fischbach, E. et al. Time-Dependent Nuclear Decay Parameters: New Evidence for New Forces? Space Science Reviews 145, 285â335 (2009).Javorsek, D. et al. Power spectrum analyses of nuclear decay rates. Astroparticle Physics 34, 173â178 (2010).Bellotti, E., Broggini, C., Di Carlo, G., Laubenstein, M. & Menegazzo, R. Search for time dependence of the 137Cs decay constant. Physics Letters B 710, 114â117 (2012)
A New Basal Sauropodomorph (Dinosauria: Saurischia) from Quebrada del Barro Formation (Marayes-El Carrizal Basin), Northwestern Argentina
BACKGROUND: Argentinean basal sauropodomorphs are known by several specimens from different basins; Ischigualasto, El Tranquilo, and Mogna. The Argentinean record is diverse and includes some of the most primitive known sauropodomorphs such as Panphagia and Chromogisaurus, as well as more derived forms, including several massospondylids. Until now, the Massospondylidae were the group of basal sauropodomorphs most widely spread around Pangea with a record in almost all continents, mostly from the southern hemisphere, including the only record from Antarctica. METHODOLOGY/PRINCIPAL FINDING: We describe here a new basal sauropodomorph, Leyesaurus marayensis gen. et sp. nov., from the Quebrada del Barro Formation, an Upper Triassic-Lower Jurassic unit that crops out in northwestern Argentina. The new taxon is represented by a partial articulated skeleton that includes the skull, vertebral column, scapular and pelvic girdles, and hindlimb. Leyesaurus is diagnosed by a set of unique features, such as a sharply acute angle (50 degrees) formed by the ascending process of the maxilla and the alveolar margin, a straight ascending process of the maxilla with a longitudinal ridge on its lateral surface, noticeably bulging labial side of the maxillary teeth, greatly elongated cervical vertebrae, and proximal articular surface of metatarsal III that is shelf-like and medially deflected. Phylogenetic analysis recovers Leyesaurus as a basal sauropodomorph, sister taxon of Adeopapposaurus within the Massospondylidae. Moreover, the results suggest that massospondylids achieved a higher diversity than previously thought. CONCLUSIONS/SIGNIFICANCE: Our phylogenetic results differ with respect to previous analyses by rejecting the massospondylid affinities of some taxa from the northern hemisphere (e.g., Seitaad, Sarahsaurus). As a result, the new taxon Leyesaurus, coupled with other recent discoveries, suggests that the diversity of massospondylids in the southern hemisphere was higher than in other regions of Pangea. Finally, the close affinities of Leyesaurus with the Lower Jurassic Massospondylus suggest a younger age for the Quebrada del Barro Formation than previously postulated
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A Search for Dark Higgs Bosons
Recent astrophysical and terrestrial experiments have motivated the proposal
of a dark sector with GeV-scale gauge boson force carriers and new Higgs
bosons. We present a search for a dark Higgs boson using 516 fb-1 of data
collected with the BABAR detector. We do not observe a significant signal and
we set 90% confidence level upper limits on the product of the Standard
Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots
for b/w printin
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
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
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