10,346 research outputs found
Reproductive capacity of the red cusk-eel genypterus chilensis (Guichenot, 1848) in captivity
IndexaciĂłn: Scopus.This work was supported by the FONDEF Project D06I 1024 âDevelopment of technologies for the production of red cusk-eel fingerlings (Genypterus chilensis)â.Genypterus chilensis is a marine fish of high gastronomic demand, whose capture has declined in recent years due to overfishing. In the development of the farming technology, high mortalities were obtained during egg incubation. The objective of this study is to contribute to the knowledge of fecundity and eggs viability of G. chilensis in captivity. The spawns of G. chilensis were analyzed over a period of 2 years and 3 months. The total fecundity was estimated by counting the masses and eggs produced monthly throughout the period. The results confirm that G. chilensis is a partial spawner, since a female may more than two masses of eggs per day, due to a large amount of mass spawned per season (621 average). The total production of masses of the Farming Centre during the period was 2,290; of these, only 7% (166) corresponding to 15,330,517 eggs were incubated. Because of its high fecundity, G. chilensis produces numerous masses of eggs, of which only a small percentage reaches incubation, as well as it occurs in other marine fish. © 2018, Escuela de Ciencias del Mar. All rights reserved.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-560X201800020048
On the determination of quantum numbers and other topics of exotic baryons
In this talk I look into three different topics, addressing first a method to
determine the quantum numbers of the , then exploiting the
possibility that the is a bound state of and in the third
place I present results on a new resonant exotic baryonic state which appears
as dynamically generated by the Weinberg Tomozawa interaction.Comment: 9 pags. Talk in the NSTAR04 Workshop, Grenoble, march 200
Hadronic aspects of exotic baryons
In this talk I look into three different topics, addressing first the
possibility that the is a bound state of , exploiting the
results of this study to find out the contribution of two meson and one baryon
components in the baryon antidecuplet and in the third place I present results
on a new resonant exotic baryonic state which appears as dynamically generated
by the Weinberg Tomozawa interaction.Comment: Talk at the International Workshop PENTAQUARK0
A mathematical model quantifies proliferation and motility effects of TGF-- on cancer cells
Transforming growth factor (TGF) is known to have properties of both
a tumor suppressor and a tumor promoter. While it inhibits cell proliferation,
it also increases cell motility and decreases cell--cell adhesion. Coupling
mathematical modeling and experiments, we investigate the growth and motility
of oncogene--expressing human mammary epithelial cells under exposure to
TGF--. We use a version of the well--known Fisher--Kolmogorov equation,
and prescribe a procedure for its parametrization. We quantify the simultaneous
effects of TGF-- to increase the tendency of individual cells and cell
clusters to move randomly and to decrease overall population growth. We
demonstrate that in experiments with TGF-- treated cells \textit{in
vitro}, TGF-- increases cell motility by a factor of 2 and decreases
cell proliferation by a factor of 1/2 in comparison with untreated cells.Comment: 15 pages, 4 figures; to appear in Computational and Mathematical
Methods in Medicin
Resistance distance, information centrality, node vulnerability and vibrations in complex networks
We discuss three seemingly unrelated quantities that have been introduced in different fields of science for complex networks. The three quantities are the resistance distance, the information centrality and the node displacement. We first prove various relations among them. Then we focus on the node displacement, showing its usefulness as an index of node vulnerability.We argue that the node displacement has a better resolution as a measure of node vulnerability than the degree and the information centrality
"Clumpiness" Mixing in Complex Networks
Three measures of clumpiness of complex networks are introduced. The measures
quantify how most central nodes of a network are clumped together. The
assortativity coefficient defined in a previous study measures a similar
characteristic, but accounts only for the clumpiness of the central nodes that
are directly connected to each other. The clumpiness coefficient defined in the
present paper also takes into account the cases where central nodes are
separated by a few links. The definition is based on the node degrees and the
distances between pairs of nodes. The clumpiness coefficient together with the
assortativity coefficient can define four classes of network. Numerical
calculations demonstrate that the classification scheme successfully
categorizes 30 real-world networks into the four classes: clumped assortative,
clumped disassortative, loose assortative and loose disassortative networks.
The clumpiness coefficient also differentiates the Erdos-Renyi model from the
Barabasi-Albert model, which the assortativity coefficient could not
differentiate. In addition, the bounds of the clumpiness coefficient as well as
the relationships between the three measures of clumpiness are discussed.Comment: 47 pages, 11 figure
Thermal Risk Mitigation Testing of the DarkNESS Observatory for Fermi NationalAccelerator Laboratory
This paper presents the prototype design and laboratory test results of the thermal control system for the Dark matter as sterile Neutrino Search Satellite (DarkNESS). A collaboration between Fermilab, CU Aerospace, and the University of Illinois Department of Aerospace Engineeringâs Laboratory for Advanced Space Systems (LASSI), the 6U satellite uses a Skipper CCD to detect weak 3.55 â 3.57 keV X-ray emissions, previously discovered by the XMM-Newton and Chandra X-ray observatories. To minimize read-out noise, the thermal control system incorporates a 10 W integral rotary cryocooler and passive heat transfer elements, maintaining the CCD at an operating temperature of 170 K. Analyses of the Earth\u27s obstruction of the instrumentâs field of view and the impact of external heating on the instrument aperture established performance requirements and attitude constraints for the thermal control system. A high-fidelity test of a preliminary design was performed in a thermal vacuum chamber, prompting modifications to improve the thermal system design margins. This effort precedes the Critical Design Review milestone
On the order of summability of the Fourier inversion formula
In this article we show that the order of the point value, in the sense of Ćojasiewicz, of a tempered distribution and the order of summability of the pointwise Fourier inversion formula are closely related. Assuming that the order of the point values and certain order of growth at infinity are given for a tempered distribution, we estimate the order of summability of the Fourier inversion formula. For Fourier series, and in other cases, it is shown that if the distribution has a distributional point value of order k, then its Fourier series is e.v. CesĂ ro summable to the distributional point value of order k+1. Conversely, we also show that if the pointwise Fourier inversion formula is e.v. CesĂ ro summable of order k, then the distribution is the (k+1)-th derivative of a locally integrable function, and the distribution has a distributional point value of order k+2. We also establish connections between orders of summability and local behavior for other Fourier inversion problems
Hadamard Regularization
Motivated by the problem of the dynamics of point-particles in high
post-Newtonian (e.g. 3PN) approximations of general relativity, we consider a
certain class of functions which are smooth except at some isolated points
around which they admit a power-like singular expansion. We review the concepts
of (i) Hadamard ``partie finie'' of such functions at the location of singular
points, (ii) the partie finie of their divergent integral. We present and
investigate different expressions, useful in applications, for the latter
partie finie. To each singular function, we associate a partie-finie (Pf)
pseudo-function. The multiplication of pseudo-functions is defined by the
ordinary (pointwise) product. We construct a delta-pseudo-function on the class
of singular functions, which reduces to the usual notion of Dirac distribution
when applied on smooth functions with compact support. We introduce and analyse
a new derivative operator acting on pseudo-functions, and generalizing, in this
context, the Schwartz distributional derivative. This operator is uniquely
defined up to an arbitrary numerical constant. Time derivatives and partial
derivatives with respect to the singular points are also investigated. In the
course of the paper, all the formulas needed in the application to the physical
problem are derived.Comment: 50 pages, to appear in Journal of Mathematical Physic
"Clumpiness" Mixing in Complex Networks
Three measures of clumpiness of complex networks are introduced. The measures
quantify how most central nodes of a network are clumped together. The
assortativity coefficient defined in a previous study measures a similar
characteristic, but accounts only for the clumpiness of the central nodes that
are directly connected to each other. The clumpiness coefficient defined in the
present paper also takes into account the cases where central nodes are
separated by a few links. The definition is based on the node degrees and the
distances between pairs of nodes. The clumpiness coefficient together with the
assortativity coefficient can define four classes of network. Numerical
calculations demonstrate that the classification scheme successfully
categorizes 30 real-world networks into the four classes: clumped assortative,
clumped disassortative, loose assortative and loose disassortative networks.
The clumpiness coefficient also differentiates the Erdos-Renyi model from the
Barabasi-Albert model, which the assortativity coefficient could not
differentiate. In addition, the bounds of the clumpiness coefficient as well as
the relationships between the three measures of clumpiness are discussed.Comment: 47 pages, 11 figure
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