Expression and function of transient receptor potential channels in the female bovine reproductive tract

© 2016 Elsevier Inc. The epithelium lining the oviduct is critical for early reproductive events, many of which are mediated via intracellular calcium ions. Despite this, little is known about the regulation of calcium homeostasis in the oviductal epithelium. Epithelial transient receptor potential channels (TRPCs) modulate calcium flux in other tissues, and their expression and functional regulation have therefore been examined using the bovine oviduct as a model for the human. The effects of FSH, LH, 17β-estradiol, and progesterone on TRPCs expression and intracellular calcium flux were determined. Transient receptor potential channels 1, 2, 3, 4, and 6 were expressed in the bovine reproductive tract, and their gene expression varied throughout the estrous cycle. In more detailed studies undertaken on TRPC1 and 6, we show that protein expression varied through the estrus cycle; specifically, 17β-estradiol, FSH, and LH individually and in combination upregulated TRPC1 and 6 expression in cultured bovine oviduct epithelial cells although progesterone antagonized these effects. Functional studies showed changes in calcium mobilization in bovine oviduct epithelial cells were dependent on TRPCs. In conclusion, TRPC1, 2, 3, 4, and 6 are present in the epithelium lining the bovine oviduct, and TRPC1 and 6 vary through the estrous cycle suggesting an important role in early reproductive function

A Semi-Analytical Analysis of Texture Collapse

This study presents a simplified approach to studying the dynamics of global texture collapse. We derive equations of motion for a spherically symmetric field configuration using a two parameter ansatz. Then we analyse the effective potential for the resulting theory to understand possible trajectories of the field configuration in the parameter space of the ansatz. Numerical results are given for critical winding and collapse time in spatially flat non-expanding, and flat expanding universes. In addition, the open non-expanding and open-expanding cases are studied.Comment: 12 pages, figures available from author, BROWN-HET-895, uses phyzz

Reparametrising the Skyrme Model using the Lithium-6 Nucleus

The minimal energy B=6 solution of the Skyrme model is a static soliton with $D_{4d}$ symmetry. The symmetries of the solution imply that the quantum numbers of the ground state are the same as those of the Lithium-6 nucleus. This identification is considered further by obtaining expressions for the mean charge radius and quadrupole moment, dependent only on the Skyrme model parameters $e$ (a dimensionless constant) and $F_\pi$ (the pion decay constant). The optimal values of these parameters have often been deliberated upon, and we propose, for $B>2$, changing them from those which are most commonly accepted. We obtain specific values for these parameters for B=6, by matching with properties of the Lithium-6 nucleus. We find further support for the new values by reconsidering the $\alpha$-particle and deuteron as quantized B=4 and B=2 Skyrmions.Comment: 18 page

The Darboux-Backlund transformation for the static 2-dimensional continuum Heisenberg chain

We construct the Darboux-Backlund transformation for the sigma model describing static configurations of the 2-dimensional classical continuum Heisenberg chain. The transformation is characterized by a non-trivial normalization matrix depending on the background solution. In order to obtain the transformation we use a new, more general, spectral problem.Comment: 12 page

Non-Singular Stationary Global Strings

A field-theoretical model for non-singular global cosmic strings is presented. The model is a non-linear sigma model with a potential term for a self-gravitating complex scalar field. Non-singular stationary solutions with angular momentum and possibly linear momentum are obtained by assuming an oscillatory dependence of the scalar field on t, phi and z. This dependence has an effect similar to gauging the global U(1) symmetry of the model, which is actually a Kaluza-Klein reduction from four to three spacetime dimensions. The method of analysis can be regarded as an extension of the gravito-electromagnetism formalism beyond the weak field limit. Some D=3 self-dual solutions are also discussed.Comment: 20 pages Latex, 12 PS figures included. Minor corrections. Version to appear in Phys.Rev.

Zero mode quantization of multi-Skyrmions

A zero mode quantization of the minimal energy SU(2) Skyrmions for nucleon numbers four to nine and seventeen is described. This involves quantizing the rotational and isorotational modes of the configurations. For nucleon numbers four, six and eight the ground states obtained are in agreement with the observed nuclear states of Helium, Lithium and Beryllium. However, for nucleon numbers five, seven, nine and seventeen the spins obtained conflict with the observed isodoublet nuclear states.Comment: 37 pages, LaTeX, 4 figures. More careful treatment of double covers, reference adde