13,534 research outputs found
Placenta Ingestion Enhances Analgesia\ud Produced by Vaginal/Cervical\ud Stimulation in Rats
Ingestion of placenta has previously been shown to enhance opiate-mediated analgesia (measured as tail-flick latency) induced either by morphine injection or by footshock. The present study was designed to test whether placenta ingestion would enhance the partly opiate-mediated analgesia produced by vaginal/cervical stimulation. Nulliparous Sprague-Dawley rats were tested for analgesia, using tail-flick latency, during and after vaginal/cervical stimulation; the tests for vaginal/cervical stimulation-induced analgesia were administered both before and after the rats ate placenta or ground beef. Placenta ingestion, but not beef ingestion. significantly heightened vaginal/cervical stimulation-induced analgesia. A subsequent morphine injection provided evidence that, as in a previous report, placenta ingestion, but not beef ingestion, enhanced morphine-induced analgesia
Star Formation in Dwarf Galaxies
We explore mechanisms for the regulation of star formation in dwarf galaxies.
We concentrate primarily on a sample in the Virgo cluster, which has HI and
blue total photometry, for which we collected H data at the Wise
Observatory. We find that dwarf galaxies do not show the tight correlation of
the surface brightness of H (a star formation indicator) with the HI
surface density, or with the ratio of this density to a dynamical timescale, as
found for large disk or starburst galaxies. On the other hand, we find the
strongest correlation to be with the average blue surface brightness,
indicating the presence of a mechanism regulating the star formation by the
older (up to 1 Gyr) stellar population if present, or by the stellar population
already formed in the present burst.Comment: 15 pages (LATEX aasms4 style) and three postscript figures, accepted
for publication in the Astrophysical Journa
Plasmid Injection and Application of Electric Pulses Alter Endogenous mRNA and Protein Expression in B16.F10 Mouse Melanomas
The application of electric pulses to tissues causes cell membrane destabilization, allowing exogenous molecules to enter the cells. This delivery technique can be used for plasmid gene therapy. Reporter gene expression after plasmid delivery with eight representative published protocols was compared in B16.F10 mouse melanoma tumors. This expression varied significantly based on the pulse parameters utilized for delivery. To observe the possible influence of plasmid injection and/or pulse application on endogenous gene expression, levels of stress-related mRNAs 4 and 24 h after delivery were determined by PCR array. Increases in mRNA levels for several inflammatory chemokines and cytokines were observed in response to plasmid injection, electric pulses alone or the combination. This upregulation was confirmed by individual real-time reverse transcription TaqMan PCR assays. Proteins were extracted at the same time points from identically treated tumors and inflammatory protein levels were assayed by enzyme-linked immunosorbent assay and by a custom multiplex bead array. Increases in inflammatory protein levels generally paralleled mRNA levels. Some differences were observed, which may have been due to differing expression kinetics. The observed upregulated expression of these cytokines and chemokines may aid or inhibit the therapeutic effectiveness of immune-based cancer gene therapies
Localization of Eigenfunctions in the Stadium Billiard
We present a systematic survey of scarring and symmetry effects in the
stadium billiard. The localization of individual eigenfunctions in Husimi phase
space is studied first, and it is demonstrated that on average there is more
localization than can be accounted for on the basis of random-matrix theory,
even after removal of bouncing-ball states and visible scars. A major point of
the paper is that symmetry considerations, including parity and time-reversal
symmetries, enter to influence the total amount of localization. The properties
of the local density of states spectrum are also investigated, as a function of
phase space location. Aside from the bouncing-ball region of phase space,
excess localization of the spectrum is found on short periodic orbits and along
certain symmetry-related lines; the origin of all these sources of localization
is discussed quantitatively and comparison is made with analytical predictions.
Scarring is observed to be present in all the energy ranges considered. In
light of these results the excess localization in individual eigenstates is
interpreted as being primarily due to symmetry effects; another source of
excess localization, scarring by multiple unstable periodic orbits, is smaller
by a factor of .Comment: 31 pages, including 10 figure
Invariant imbedding technique applied to the propagation of electromagnetic waves through inhomogeneous reentry plasmas
Invariant imbedding technique applied to electromagnetic wave propagation through inhomogeneous reentry plasma
The Inhibition of Mixing in Chaotic Quantum Dynamics
We study the quantum chaotic dynamics of an initially well-localized wave
packet in a cosine potential perturbed by an external time-dependent force. For
our choice of initial condition and with small but finite, we find that
the wave packet behaves classically (meaning that the quantum behavior is
indistinguishable from that of the analogous classical system) as long as the
motion is confined to the interior of the remnant separatrix of the cosine
potential. Once the classical motion becomes unbounded, however, we find that
quantum interference effects dominate. This interference leads to a long-lived
accumulation of quantum amplitude on top of the cosine barrier. This pinning of
the amplitude on the barrier is a dynamic mechanism for the quantum inhibition
of classical mixing.Comment: 20 pages, RevTeX format with 6 Postscript figures appended in
uuencoded tar.Z forma
Influenced of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)2As2 bilayers
The implementation of an Fe buffer layer is a promising way to obtain
epitaxial growth of Co-doped BaFe2As2 (Ba-122). However, the crystalline
quality and the superconducting properties of Co-doped Ba-122 are influenced by
the Fe buffer layer thickness, dFe. The well-textured growth of the Fe/Ba-122
bilayer with dFe = 15 nm results in a high Jc of 0.45 MAcm at 12 K in
self-field, whereas a low Jc value of 61000 Acm is recorded for the
bilayer with dFe = 4 nm at the corresponding reduced temperature due to the
presence of grain boundaries
Intertwining technique for a system of difference Schroedinger equations and new exactly solvable multichannel potentials
The intertwining operator technique is applied to difference Schroedinger
equations with operator-valued coefficients. It is shown that these equations
appear naturally when a discrete basis is used for solving a multichannel
Schroedinger equation. New families of exactly solvable multichannel
Hamiltonians are found
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