12,457 research outputs found
Microscopic optical potential from chiral nuclear forces
The energy- and density-dependent single-particle potential for nucleons is
constructed in a medium of infinite isospin-symmetric nuclear matter starting
from realistic nuclear interactions derived within the framework of chiral
effective field theory. The leading-order terms from both two- and
three-nucleon forces give rise to real, energy-independent contributions to the
nucleon self-energy. The Hartree-Fock contribution from the two-nucleon force
is attractive and strongly momentum dependent, in contrast to the contribution
from the three-nucleon force which provides a nearly constant repulsive mean
field that grows approximately linearly with the nuclear density. Together, the
leading-order perturbative contributions yield an attractive single-particle
potential that is however too weak compared to phenomenology. Second-order
contributions from two- and three-body forces then provide the additional
attraction required to reach the phenomenological depth. The imaginary part of
the optical potential, which is positive (negative) for momenta below (above)
the Fermi momentum, arises at second-order and is nearly inversion-symmetric
about the Fermi surface when two-nucleon interactions alone are present. The
imaginary part is strongly absorptive and requires the inclusion of an
effective mass correction as well as self-consistent single-particle energies
to attain qualitative agreement with phenomenology.Comment: 12 pages, 7 figures, added references, corrected typo
Comparison of rocket-borne probes for electron density measurements Quarterly status report no. 5, Aug. 1 - Oct. 31, 1965
Impedance, resonance, capacitance, electrostatic, and Langmuir probe performance for ionospheric electron density profil
Autumn Twilight : Reverie D\u27Amour
https://digitalcommons.library.umaine.edu/mmb-ps/1382/thumbnail.jp
Sweet Sabbath Bells : Fantaisie de Concert
https://digitalcommons.library.umaine.edu/mmb-ps/3292/thumbnail.jp
Quantum-limited mass flow of liquid He
We consider theoretically the possibility of observing unusual quantum fluid
behavior in liquid He and solutions of He in He systems
confined to nano-channels. In the case of pure ballistic flow at very low
temperature conductance will be quantized in units of . We show that
these steps should be sensitive to increases in temperature. We also use of a
random scattering matrix simulation to study flow with diffusive wall
scattering. Universal conductance fluctuations analogous to those seen in
electron systems should then be observable. Finally we consider the possibility
of the cross-over to a one-dimensional system at sufficiently low temperature
where the system could form a Luttinger liquid
Integrated cost-benefit analysis of tsetse control and herd productivity to inform control programs for animal African trypanosomiasis
Animal African trypanosomiasis (AAT) and its tsetse vector are responsible for annual losses estimated in billions of US dollars ($). Recent years have seen the implementation of a series of multinational interventions. However, actors of AAT control face complex resource allocation decisions due to the geographical range of AAT, diversity of ecological and livestock systems, and range of control methods available. The study presented here integrates an existing tsetse abundance model with a bio-economic herd model that captures local production characteristics as well as heterogeneities in AAT incidence and breed. These models were used to predict the impact of tsetse elimination on the net value of cattle production in the districts of Mambwe, in Zambia, and Faro et Déo in Cameroon. The net value of cattle production under the current situation was used as a baseline, and compared with alternative publicly funded control programmes. In Zambia, the current baseline is AAT control implemented privately by cattle owners (Scenario Z0). In Cameroon, the baseline (Scenario C0) is a small-scale publicly funded tsetse control programme and privately funded control at farm level. The model was run for 10 years, using a discount rate of 5%
Vascular Smooth Muscle as a Therapeutic Target in Disease Pathology
Our circulatory system is composed of numerous elements that are responsible for transport of blood and delivery of essential nutrients and gases to vital downstream tissues. Among these components that make up our circulation is vascular smooth muscle (VSM), the primary muscular and contractile element of blood vessels and regulator of many blood vessel functions. This is of particular importance as cardiovascular disease (CVD), the number one killer of individuals in America and worldwide, is primarily vascular in origin. Logically, identifying and characterizing feasible targets that could control CVD are highly appealing and much desired. With this in mind and given its centrality in control of vascular physiology, VSM has gained wide attention as a plausible target to combat elements of CVD. This book chapter focuses on VSM as a potential therapeutic target against CVD and will provide overview of vascular anatomy and physiology and brief discussions about the pivotal roles of VSM in CVD pathology, the influence of abnormal blood flow mechanics and hemodynamics in CVD, neural control of VSM and the vasculature, and possible novel cellular and molecular signaling targets that could be used to control and/or minimize CVD. This chapter hopes to serve as a valuable resource for basic and applied scientists as well as clinicians interested in understanding the crucial roles that VSM plays in vessel physiology and pathology
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