Method for promoting ovulation, parturition, and lactation in mammals

The present invention generally relates to various methods for promoting ovulation, parturition and lactation in female mammals. These benefits are obtained by administering to the mammals a composition containing a D.sub.2 receptor antagonist that does not substantially cross the blood brain barrier. In one embodiment, the D.sub.2 receptor antagonist is domperidone. The domperidone can be administered to the mammal either orally or subcutaneously and can be used to treat, for instance, anestrous mammals, mammals that have problems bearing offspring and mammals suffering from agalactia. Unexpectedly, it has also been discovered that the D.sub.2 receptor antagonist may also stimulate feed intake, causing the mammal to eat more and gain weight faster

Method for promoting ovulation, parturition, and lactation in mammals

The present invention generally relates to various methods for promoting ovulation, parturition and lactation in female mammals. These benefits are obtained by administering to the mammals a composition containing a D.sub.2 receptor antagonist that does not substantially cross the blood brain barrier. In one embodiment, the D.sub.2 receptor antagonist is domperidone. The domperidone can be administered to the mammal either orally or subcutaneously and can be used to treat, for instance, anestrous mammals, mammals that have problems bearing offspring and mammals suffering from agalactia. Unexpectedly, it has also been discovered that the D.sub.2 receptor antagonist may also stimulate feed intake, causing the mammal to eat more and gain weight faster

Laminitis in horses

The present invention generally relates to various methods for treating the laminitis syndrome in animals. These benefits are obtained by administering to the animals a composition containing an .alpha.-adrenergic antagonist that does not substantially cross the blood brain barrier. In one embodiment, the .alpha.-adrenergic antagonist is domperidone. The domperidone can be administered to the animal either orally, subcutaneously, or intramuscularly and can be used to treat animals suffering from symptoms of laminitis

Method of treating fescue toxicosis with domperidone

A novel method for using domperidone, a dopamine receptor antagonist, for treating fescue toxicosis in animals is provided. Fescue toxicosis is caused by animals grazing on endophyte-infected fescue grass. Treatment of the animal with various dosages of domperidone results in effective management of the toxin. The domperidone treatments do not cause any substantial adverse behavioral or neurological side effects in the animal. Domperidone is a more effective treatment for fescue toxicosis than previously-known agents such a metoclopramide and sulpiride

Multiple Front Propagation Into Unstable States

The dynamics of transient patterns formed by front propagation in extended nonequilibrium systems is considered. Under certain circumstances, the state left behind a front propagating into an unstable homogeneous state can be an unstable periodic pattern. It is found by a numerical solution of a model of the Fr\'eedericksz transition in nematic liquid crystals that the mechanism of decay of such periodic unstable states is the propagation of a second front which replaces the unstable pattern by a another unstable periodic state with larger wavelength. The speed of this second front and the periodicity of the new state are analytically calculated with a generalization of the marginal stability formalism suited to the study of front propagation into periodic unstable states. PACS: 47.20.Ky, 03.40.Kf, 47.54.+rComment: 12 page

Pattern selection as a nonlinear eigenvalue problem

A unique pattern selection in the absolutely unstable regime of driven, nonlinear, open-flow systems is reviewed. It has recently been found in numerical simulations of propagating vortex structures occuring in Taylor-Couette and Rayleigh-Benard systems subject to an externally imposed through-flow. Unlike the stationary patterns in systems without through-flow the spatiotemporal structures of propagating vortices are independent of parameter history, initial conditions, and system length. They do, however, depend on the boundary conditions in addition to the driving rate and the through-flow rate. Our analysis of the Ginzburg-Landau amplitude equation elucidates how the pattern selection can be described by a nonlinear eigenvalue problem with the frequency being the eigenvalue. Approaching the border between absolute and convective instability the eigenvalue problem becomes effectively linear and the selection mechanism approaches that of linear front propagation. PACS: 47.54.+r,47.20.Ky,47.32.-y,47.20.FtComment: 18 pages in Postsript format including 5 figures, to appear in: Lecture Notes in Physics, "Nonlinear Physics of Complex Sytems -- Current Status and Future Trends", Eds. J. Parisi, S. C. Mueller, and W. Zimmermann (Springer, Berlin, 1996

Formation of Liesegang patterns: A spinodal decomposition scenario

Spinodal decomposition in the presence of a moving particle source is proposed as a mechanism for the formation of Liesegang bands. This mechanism yields a sequence of band positions x_n that obeys the spacing law x_n~Q(1+p)^n. The dependence of the parameters p and Q on the initial concentration of the reagents is determined and we find that the functional form of p is in agreement with the experimentally observed Matalon-Packter law.Comment: RevTex, 4 pages, 4 eps figure

Pearling and Pinching: Propagation of Rayleigh Instabilities

A new category of front propagation problems is proposed in which a spreading instability evolves through a singular configuration before saturating. We examine the nature of this front for the viscous Rayleigh instability of a column of one fluid immersed in another, using the marginal stability criterion to estimate the front velocity, front width, and the selected wavelength in terms of the surface tension and viscosity contrast. Experiments are suggested on systems that may display this phenomenon, including droplets elongated in extensional flows, capillary bridges, liquid crystal tethers, and viscoelastic fluids. The related problem of propagation in Rayleigh-like systems that do not fission is also considered.Comment: Revtex, 7 pages, 4 ps figs, PR

Localization-delocalization transition of a reaction-diffusion front near a semipermeable wall

The A+B --> C reaction-diffusion process is studied in a system where the reagents are separated by a semipermeable wall. We use reaction-diffusion equations to describe the process and to derive a scaling description for the long-time behavior of the reaction front. Furthermore, we show that a critical localization-delocalization transition takes place as a control parameter which depends on the initial densities and on the diffusion constants is varied. The transition is between a reaction front of finite width that is localized at the wall and a front which is detached and moves away from the wall. At the critical point, the reaction front remains at the wall but its width diverges with time [as t^(1/6) in mean-field approximation].Comment: 7 pages, PS fil

Fluctuating "Pulled" Fronts: the Origin and the Effects of a Finite Particle Cutoff

Recently it has been shown that when an equation that allows so-called pulled fronts in the mean-field limit is modelled with a stochastic model with a finite number $N$ of particles per correlation volume, the convergence to the speed $v^*$ for $N \to \infty$ is extremely slow -- going only as $\ln^{-2}N$. In this paper, we study the front propagation in a simple stochastic lattice model. A detailed analysis of the microscopic picture of the front dynamics shows that for the description of the far tip of the front, one has to abandon the idea of a uniformly translating front solution. The lattice and finite particle effects lead to a ``stop-and-go'' type dynamics at the far tip of the front, while the average front behind it ``crosses over'' to a uniformly translating solution. In this formulation, the effect of stochasticity on the asymptotic front speed is coded in the probability distribution of the times required for the advancement of the ``foremost bin''. We derive expressions of these probability distributions by matching the solution of the far tip with the uniformly translating solution behind. This matching includes various correlation effects in a mean-field type approximation. Our results for the probability distributions compare well to the results of stochastic numerical simulations. This approach also allows us to deal with much smaller values of $N$ than it is required to have the $\ln^{-2}N$ asymptotics to be valid.Comment: 26 pages, 11 figures, to appear in Phys. rev.