9,771 research outputs found
The metastasis inducer CCN1 (CYR61) activates the fatty acid synthase (FASN)-driven lipogenic phenotype in breast cancer cells
The angiogenic inducer CCN1 (Cysteine-rich 61, CYR61) is differentially activated in metastatic breast carcinomas. However, little is known about the precise mechanisms that underlie the pro-metastatic actions of CCN1. Here, we investigated the impact of CCN1 expression on fatty acid synthase (FASN), a metabolic oncogene thought to provide cancer cells with proliferative and survival advantages. Forced expression of CCN1 in MCF-7 cells robustly up-regulated FASN protein expression and also significantly increased FASN gene promoter activity 2- to 3-fold, whereas deletion of the sterol response element-binding protein (SREBP) binding site in the FASN promoter completely abrogated CCN1-driven transcriptional activation. Pharmacological blockade of MAPK or PI-3´K activation similarly prevented the ability of CCN1 to induce FASN gene activation. Pharmacological inhibition of FASN activity with the mycotoxin cerulenin or the small compound C75 reversed CCN1-induced acquisition of estrogen independence and resistance to hormone therapies such as tamoxifen and fulvestrant in anchorage-independent growth assays. This study uncovers FASNdependent endogenous lipogenesis as a new mechanism controlling the metastatic phenotype promoted by CCN1. Because estrogen independence and progression to a metastatic phenotype are hallmarks of therapeutic resistance and mortality in breast cancer, this previously unrecognized CCN1-driven lipogenic phenotype represents a novel metabolic target to clinically manage metastatic disease progression.Fil: Menendez, Javier A.. Instituto Catalán de Oncología; España. Institut d; EspañaFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Espinoza, Ingrid. University Of Mississippi; Estados UnidosFil: Lupu, Ruth. Mayo Clinic Cancer Center; Estados Unido
Nuclear forces and their impact on neutron-rich nuclei and neutron-rich matter
We review the impact of nuclear forces on matter at neutron-rich extremes.
Recent results have shown that neutron-rich nuclei become increasingly
sensitive to three-nucleon forces, which are at the forefront of theoretical
developments based on effective field theories of quantum chromodynamics. This
includes the formation of shell structure, the spectroscopy of exotic nuclei,
and the location of the neutron dripline. Nuclear forces also constrain the
properties of neutron-rich matter, including the neutron skin, the symmetry
energy, and the structure of neutron stars. We first review our understanding
of three-nucleon forces and show how chiral effective field theory makes unique
predictions for many-body forces. Then, we survey results with three-nucleon
forces in neutron-rich oxygen and calcium isotopes and neutron-rich matter,
which have been explored with a range of many-body methods. Three-nucleon
forces therefore provide an exciting link between theoretical, experimental and
observational nuclear physics frontiers.Comment: 28 pages, 13 figures, 1 tabl
Three-nucleon forces and spectroscopy of neutron-rich calcium isotopes
We study excited-state properties of neutron-rich calcium isotopes based on
chiral two- and three-nucleon interactions. We first discuss the details of our
many-body framework, investigate convergence properties, and for two-nucleon
interactions benchmark against coupled-cluster calculations. We then focus on
the spectroscopy of 47-56Ca, finding that with both 3N forces and an extended
pfg9/2 valence space, we obtain a good level of agreement with experiment. We
also study electromagnetic transitions and find that experimental data are well
described by our calculations. In addition, we provide predictions for
unexplored properties of neutron-rich calcium isotopes.Comment: 15 pages, 22 figures, published versio
Exploring sd-shell nuclei from two- and three-nucleon interactions with realistic saturation properties
We study ground- and excited-state properties of all sd-shell nuclei with
neutron and proton numbers 8 <= N,Z <= 20, based on a set of low-resolution
two- and three-nucleon interactions that predict realistic saturation
properties of nuclear matter. We focus on estimating the theoretical
uncertainties due to variation of the resolution scale, the low-energy
couplings, as well as from the many-body method. The experimental two-neutron
and two-proton separation energies are reasonably well reproduced, with an
uncertainty range of about 5 MeV. The first excited 2+ energies also show
overall agreement, with a more narrow uncertainty range of about 500 keV. In
most cases, this range is dominated by the uncertainties in the Hamiltonian.Comment: 6 pages, 4 figure
Supplementary report to the final report of the coral reef expert group: S5. Statistical power of existing AIMS Long-Term Reef Monitoring Programs
[Extract] This report presents estimates of power to detect changes in the rate of coral cover recovery and species richness of herbivorous fishes. Estimates are based on the variability in existing time-series derived from the Australian Institute of Marine Science (AIMS) long-term reef monitoring programs. The objective is to provide a basis for monitoring program design considerations under the Reef 2050 Integrated Monitoring and Reporting Program (RIMReP).
Collectively, the AIMS programs provide the only time series of sufficient spatial and temporal coverage to allow estimation of variability at the scales necessary for considering design options at the scale of the Great Barrier Reef (the Reef).An accessible copy of this report is not yet available from this repository, please contact [email protected] for more information
Signatures of Dark Matter Scattering Inelastically Off Nuclei
Direct dark matter detection focuses on elastic scattering of dark matter
particles off nuclei. In this study, we explore inelastic scattering where the
nucleus is excited to a low-lying state of 10-100 keV, with subsequent prompt
de-excitation. We calculate the inelastic structure factors for the odd-mass
xenon isotopes based on state-of-the-art large-scale shell-model calculations
with chiral effective field theory WIMP-nucleon currents. For these cases, we
find that the inelastic channel is comparable to or can dominate the elastic
channel for momentum transfers around 150 MeV. We calculate the inelastic
recoil spectra in the standard halo model, compare these to the elastic case,
and discuss the expected signatures in a xenon detector, along with
implications for existing and future experiments. The combined information from
elastic and inelastic scattering will allow to determine the dominant
interaction channel within one experiment. In addition, the two channels probe
different regions of the dark matter velocity distribution and can provide
insight into the dark halo structure. The allowed recoil energy domain and the
recoil energy at which the integrated inelastic rates start to dominate the
elastic channel depend on the mass of the dark matter particle, thus providing
a potential handle to constrain its mass.Comment: 9 pages, 7 figures. Matches resubmitted version to Phys. Rev. D. One
figure added; supplemental material (fits to the structure functions) added
as an Appendi
Inelastic light scattering and the excited states of many-electron quantum dots
A consistent calculation of resonant inelastic (Raman) scattering amplitudes
for relatively large quantum dots, which takes account of valence-band mixing,
discrete character of the spectrum in intermediate and final states, and
interference effects, is presented. Raman peaks in charge and spin channels are
compared with multipole strengths and with the density of energy levels in
final states. A qualitative comparison with the available experimental results
is given.Comment: 5 pages, accepted in J. Phys.: Condens. Matte
Genetic and environmental factors affecting some reproductive traits of Holstein cows in Cuba
International audienc
Nonlinear Breathing-like Localized Modes in C60 Nanocrystals
We study the dynamics of nanocrystals composed of C60 fullerene molecules. We
demonstrate that such structures can support long-lived strongly localized
nonlinear oscillatory modes, which resemble discrete breathers in simple
lattices. We reveal that at room temperatures the lifetime of such nonlinear
localized modes may exceed tens of picoseconds; this suggests that C60
nanoclusters should demonstrate anomalously slow thermal relaxation when the
temperature gradient decays in accord to a power law, thus violating the
Cattaneo-Vernotte law of thermal conductivity.Comment: 6 pages, 6 figure
Spin-dependent WIMP scattering off nuclei
Chiral effective field theory (EFT) provides a systematic expansion for the
coupling of WIMPs to nucleons at the momentum transfers relevant to direct cold
dark matter detection. We derive the currents for spin-dependent WIMP
scattering off nuclei at the one-body level and include the leading long-range
two-body currents, which are predicted in chiral EFT. As an application, we
calculate the structure factor for spin-dependent WIMP scattering off 129,131Xe
nuclei, using nuclear interactions that have been developed to study nuclear
structure and double-beta decays in this region. We provide theoretical error
bands due to the nuclear uncertainties of WIMP currents in nuclei.Comment: 6 pages, 3 figures, published versio
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