1,929 research outputs found
Quantum chaos and nuclear mass systematics
The presence of quantum chaos in nuclear mass systematics is analyzed by
considering the differences between measured and calculated nuclear masses as a
time series described by the power law 1/ f^alpha. While for the liquid droplet
model plus shell corrections a quantum chaotic behavior alpha approx 1 is
found, errors in the microscopic mass formula have alpha approx 0.5, closer to
white noise. The chaotic behavior seems to arise from many body effects not
included in the mass formula.Comment: 4 pages, 6 figures, replaced to match the published versio
The k-metric dimension of a graph
As a generalization of the concept of a metric basis, this article introduces
the notion of -metric basis in graphs. Given a connected graph , a
set is said to be a -metric generator for if the elements
of any pair of different vertices of are distinguished by at least
elements of , i.e., for any two different vertices , there exist
at least vertices such that for every . A metric generator of minimum
cardinality is called a -metric basis and its cardinality the -metric
dimension of . A connected graph is -metric dimensional if is the
largest integer such that there exists a -metric basis for . We give a
necessary and sufficient condition for a graph to be -metric dimensional and
we obtain several results on the -metric dimension
The CCL5/CCR5 axis promotes metastasis in basal breast cancer.
Recently, we have shown that the CCL5/CCR5 axis is active in patients affected by an aggressive basal subtype of breast cancer. Using preclinical models, we have demonstrated that CCR5 promotes breast cancer invasiveness and metastatic potential, while CCR5 inhibition abrogates them. Thus, CCR5 antagonists may constitute an alternative therapeutic approach for patients affected by metastatic basal breast cancer
Band Crossing and Signature Splitting in Odd Mass fp Shell Nuclei
Structure of two sets of mirror nuclei: 47V - 47Cr and 49Cr - 49Mn, as well
as 49V and 51Mn, is studied using the projected shell model. Their yrast
spectra are described as an interplay between the angular momentum projected
states around the Fermi level which carry different intrinsic K-quantum
numbers. The deviations from a regular rotational sequence are attributed to
band crossing and signature splitting, which are usually discussed in heavy
nuclear systems. Our results agree reasonably with experimental data, and are
comparable with those from the full shell model calculations.Comment: 3 figures, submitted to Nucl. Phys.
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