461 research outputs found
Evidence for particle-hole excitations in the triaxial strongly-deformed well of ^{163}Tm
Two interacting, strongly-deformed triaxial (TSD) bands have been identified
in the Z = 69 nucleus ^{163}Tm. This is the first time that interacting TSD
bands have been observed in an element other than the Z = 71 Lu nuclei, where
wobbling bands have been previously identified. The observed TSD bands in
^{163}Tm appear to be associated with particle-hole excitations, rather than
wobbling. Tilted-Axis Cranking (TAC) calculations reproduce all experimental
observables of these bands reasonably well and also provide an explanation for
the presence of wobbling bands in the Lu nuclei, and their absence in the Tm
isotopes.Comment: 13 pages, 7 figure
High-spin structure and Band Termination in Cd
Excited states of the neutron deficient Cd nucleus have been
investigated via the Ge(Cl, p3n) reaction at beam energy of 135
MeV by use of in-beam spectroscopic methods. Gamma rays depopulating the
excited states were detected using the Gammasphere spectrometer with high-fold
-ray coincidences. A quadrupole -ray coincidence analysis
() has been used to extend the known level scheme. The positive
parity levels have been established up to and
MeV. In addition to the observation of highly-fragmented level scheme belonging
to the positive-parity sequences at E 5 MeV, the termination of a
negative-parity sequence connected by transitions has been established at
and MeV. The experimental results
corresponding to both the positive- and negative-parity sequences have been
theoretically interpreted in the framework of the core particle coupling model.
Evidence is presented for a shape change from collective prolate to
non-collective oblate above the (8011 keV) level and for a
smooth termination of the negative-parity band.Comment: 19 pages, 8 figures. Submitted to Phys. Rev.
High-spin structure and Band Termination in Cd
Excited states of the neutron deficient Cd nucleus have been
investigated via the Ge(Cl, p3n) reaction at beam energy of 135
MeV by use of in-beam spectroscopic methods. Gamma rays depopulating the
excited states were detected using the Gammasphere spectrometer with high-fold
-ray coincidences. A quadrupole -ray coincidence analysis
() has been used to extend the known level scheme. The positive
parity levels have been established up to and
MeV. In addition to the observation of highly-fragmented level scheme belonging
to the positive-parity sequences at E 5 MeV, the termination of a
negative-parity sequence connected by transitions has been established at
and MeV. The experimental results
corresponding to both the positive- and negative-parity sequences have been
theoretically interpreted in the framework of the core particle coupling model.
Evidence is presented for a shape change from collective prolate to
non-collective oblate above the (8011 keV) level and for a
smooth termination of the negative-parity band.Comment: 19 pages, 8 figures. Submitted to Phys. Rev.
A Composite Chiral Pair of Rotational Bands in the odd-A Nucleus 135Nd
High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd
reaction at a 30Si bombarding energy of 133 MeV. Two Delta(I)=1 bands with
close excitation energies and the same parity were observed. These bands are
directly linked by Delta(I)=1 and Delta(I)=2 transitions. The chiral nature of
these two bands is confirmed by comparison with three-dimensional tilted axis
cranking calculations. This is the first observation of a three-quasiparticle
chiral structure and established the primarily geometric nature of this
phenomenon.Comment: 10 pages, 5 figures (1 in color), 1 table, submitted to Physics
Review Letters, written in REVTEX4 forma
Lifetime measurements of Triaxial Strongly Deformed bands in Tm
With the Doppler Shift Attenuation Method, quadrupole transition moments,
, were determined for the two recently proposed Triaxial Strongly Deformed
(TSD) bands in Tm. The measured moments indicate that the
deformation of these bands is larger than that of the yrast, signature
partners. However, the measured values are smaller than those predicted by
theory. This observation appears to be valid for TSD bands in several nuclei of
the regionComment: 8 pages, 5 figures. Submitted to Physical Review
An Intrinsically Disordered Region of the Acetyltransferase p300 with Similarity to Prion-Like Domains Plays a Role in Aggregation
Several human diseases including neurodegenerative disorders and cancer are associated with abnormal accumulation and aggregation of misfolded proteins. Proteins with high tendency to aggregate include the p53 gene product, TAU and alpha synuclein. The potential toxicity of aberrantly folded proteins is limited via their transport into intracellular sub-compartments, the aggresomes, where misfolded proteins are stored or cleared via autophagy. We have identified a region of the acetyltransferase p300 that is highly disordered and displays similarities with prion-like domains. We show that this region is encoded as an alternative spliced variant independently of the acetyltransferase domain, and provides an interaction interface for various misfolded proteins, promoting their aggregation. p300 enhances aggregation of TAU and of p53 and is a component of cellular aggregates in both tissue culture cells and in alpha-synuclein positive Lewy bodies of patients affected by Parkinson disease. Down-regulation of p300 impairs aggresome formation and enhances cytotoxicity induced by misfolded protein stress. These data unravel a novel activity of p300, offer new insights into the function of disordered domains and implicate p300 in pathological aggregation that occurs in neurodegeneration and cancer
Complex ferromagnetic state and magnetocaloric effect in single crystalline Nd_{0.7}Sr_{0.3}MnO_{3}
The magnetocaloric effect in single crystalline Nd_{0.7}Sr_{0.3}MnO_{3} is
investigated by measuring the field-induced adiabatic change in temperature
which reveals a single negative peak around 130 K well below the Curie
temperature (T_C=203 K). In order to understand this unusual magnetocaloric
effect, we invoke the reported {55}^Mn spin-echo nuclear magnetic resonance,
electron magnetic resonance and polarized Raman scattering measurements on
Nd_{0.7}Sr_{0.3}MnO_{3}. We show that this effect is a manifestation of a
competition between the double exchange mechanism and correlations arising from
coupled spin and lattice degrees of freedom which results in a complex
ferromagnetic state. The critical behavior of Nd_{0.7}Sr_{0.3}MnO_{3} near
Curie temperature is investigated to study the influence of the coupled degrees
of freedom. We find a complicated behavior at low fields in which the order of
the transition could not be fixed and a second-order-like behavior at high
fields.Comment: Accepted for publication in Phys. Rev.
Understanding the Dynamical State of Globular Clusters: Core-Collapsed vs Non Core-Collapsed
We study the dynamical evolution of globular clusters using our H\'enon-type
Monte Carlo code for stellar dynamics including all relevant physics such as
two-body relaxation, single and binary stellar evolution, Galactic tidal
stripping, and strong interactions such as physical collisions and binary
mediated scattering. We compute a large database of several hundred models
starting from broad ranges of initial conditions guided by observations of
young and massive star clusters. We show that these initial conditions very
naturally lead to present day clusters with properties including the central
density, core radius, half-light radius, half-mass relaxation time, and cluster
mass, that match well with those of the old Galactic globular clusters. In
particular, we can naturally reproduce the bimodal distribution in observed
core radii separating the "core-collapsed" vs the "non core-collapsed"
clusters. We see that the core-collapsed clusters are those that have reached
or are about to reach the equilibrium "binary burning" phase. The non
core-collapsed clusters are still undergoing gravo-thermal contraction.Comment: 42 pages, 12 figures, 1 table, submitted to MNRA
miR-139-5p is a regulator of metastatic pathways in breast cancer
Metastasis is a complex, multistep process involved in the progression of cancer from a localized primary tissue to distant sites, often characteristic of the more aggressive forms of this disease. Despite being studied in great detail in recent years, the mechanisms that govern this process remain poorly understood. In this study, we identify a novel role for miR-139-5p in the inhibition of breast cancer progression. We highlight its clinical relevance by reviewing miR-139-5p expression across a wide variety of breast cancer subtypes using in-house generated and online data sets to show that it is most frequently lost in invasive tumors. A biotin pull-down approach was then used to identify the mRNA targets of miR-139-5p in the breast cancer cell line MCF7. Functional enrichment analysis of the pulled-down targets showed significant enrichment of genes in pathways previously implicated in breast cancer metastasis (P < 0.05). Further bioinformatic analysis revealed a predicted disruption to the TGFΞ², Wnt, Rho, and MAPK/PI3K signaling cascades, implying a potential role for miR-139-5p in regulating the ability of cells to invade and migrate. To corroborate this finding, using the MDA-MB-231 breast cancer cell line, we show that overexpression of miR-139-5p results in suppression of these cellular phenotypes. Furthermore, we validate the interaction between miR-139-5p and predicted targets involved in these pathways. Collectively, these results suggest a significant functional role for miR-139-5p in breast cancer cell motility and invasion and its potential to be used as a prognostic marker for the aggressive forms of breast cancer
ΠΡΠΈΠ½ΡΠΈΠΏΡ ΡΡΡΠ°ΡΠ΅Π³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΠ»Π°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π΄Π΅ΡΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ Π½Π΅ΡΡΡΠ½ΠΎΠΉ ΠΊΠΎΠΌΠΏΠ°Π½ΠΈΠΈ ΠΠΎΡ ΠβΠΠ²ΡΠ°Ρ
Π ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΡΡ: Π°Π½Π°Π»ΠΈΠ· ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΠΌΠΈΡΠΎΠ²ΡΡ
ΡΠ΅Π½Π΄Π΅Π½ΡΠΈΠΉ ΡΠ°Π·Π²ΠΈΡΠΈΡ Π½Π΅ΡΡΠ΅Π³Π°Π·ΠΎΠ²ΠΎΠΉ ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΡΡΠΈ; Π±ΡΠ»ΠΈ ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Ρ ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΠΏΡΠΈΠ½ΡΠΈΠΏΡ ΠΈ ΠΌΠ΅ΡΠΎΠ΄Ρ ΡΡΡΠ°ΡΠ΅Π³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΠ»Π°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΊΠΎΠΌΠΏΠ°Π½ΠΈΠΉ ΡΠΎΡΡΠΈΠΉΡΠΊΠΎΠ³ΠΎ Π½Π΅ΡΡΠ΅Π³Π°Π·ΠΎΠ²ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ°; Π½Π° ΠΏΡΠΈΠΌΠ΅ΡΠ΅ ΠΊΠΎΠ½ΠΊΡΠ΅ΡΠ½ΡΡ
ΠΊΠΎΠΌΠΏΠ°Π½ΠΈΠΉ; ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ ΡΡΠ°Π²Π½ΠΈΡΠ΅Π»ΡΠ½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΠΈ ΠΏΡΠΈΠ½ΡΠΈΠΏΠΎΠ² ΡΡΡΠ°ΡΠ΅Π³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΠ»Π°Π½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΠΠ Π ΠΎΡΡΠΈΠΈ ΠΈ Π½Π΅ΡΡΠ΅Π³Π°Π·ΠΎΠ²ΠΎΠ³ΠΎ ΡΠ΅ΠΊΡΠΎΡΠ° ΠΠΎΡ-Π΄βΠΠ²ΡΠ°ΡΠ°.In the process of the study, the analysis of the current global trends in the development of the oil and gas industry was carried out; the main principles and methods of strategic planning for the development of companies of the Russian oil and gas complex were analyzed; on the example of specific companies; a comparative analysis of the methods and principles of strategic planning of the Russian oil and gas industry and the oil and gas sector in Cote d'Ivoire
- β¦