Eurycea junaluska

Number of Pages: 2Integrative BiologyGeological Science

Eurycea wilderae

Number of Pages: 4Integrative BiologyGeological Science

Ultrastructure of the reproductive system of the black swamp snake (\u3ci\u3eSeminatrix pygaea\u3c/i\u3e). Part III. The sexual segment of the male kidney.

In mature male snakes and lizards, a distal portion of the nephron is hypertrophied in relation to its appearance in females and immature males. This sexual segment of the male kidney apparently provides seminal fluid that is mixed with sperm and released into the female cloaca during copulation. In this article, we provide the first study at the ultrastructural level of seasonal variation in the sexual segment of the kidney of a squamate, the natricine snake Seminatrix pygaea. Previous workers have indicated that the sexual segment is secretory only when the testes are spermatogenically active. The sexual segment of the kidney in S. pygaea does not go through an extended period of inactivity but does show a cycle of synthesis and secretion that can be related to the spermatogenic cycle and mating activity. We show that synthesis of secretory product is initiated with the onset of spermatogenic activity in the spring and culminates with completion of spermiation in the fall. Secretion of the product, however, occurs in a premating period in March when the testes are inactive. Secretion during this premating period is probably necessary to provide time for the passage of the products down the ureter in order to mix with spermduring mating later in spring

Exact Quantization Rule to the Kratzer-Type Potentials: An Application to the Diatomic Molecules

For any arbitrary values of $n$ and $l$ quantum numbers, we present a simple exact analytical solution of the $D$-dimensional ($D\geq 2$) hyperradial Schr% \"{o}dinger equation with the Kratzer and the modified Kratzer potentials within the framework of the exact quantization rule (EQR) method. The exact energy levels $(E_{nl})$ of all the bound-states are easily calculated from this EQR method. The corresponding normalized hyperradial wave functions $(\psi_{nl}(r))$ are also calculated. The exact energy eigenvalues for these Kratzer-type potentials are calculated numerically for the typical diatomic molecules $LiH,$ $CH,$ $HCl,$ $CO,$ $NO,$ $O_{2},$ $N_{2}$ and $I_{2}$ for various values of $n$ and $l$ quantum numbers. Numerical tests using the energy calculations for the interdimensional degeneracy ($D=2-4$) for $I_{2},$ $LiH,$ $HCl,$ $O_{2},$ $NO$ and $CO$ are also given. Our results obtained by EQR are in exact agreement with those obtained by other methods.Comment: 26 page

A perturbative treatment for the bound states of the Hellmann potential

A new approximation formalism is applied to study the bound states of the Hellmann potential, which represents the superposition of the attractive Coulomb potential $-a/r$ and the Yukawa potential $b\exp (-\delta r)/r$ of arbitrary strength $b$ and screening parameter $\delta$. Although the analytic expressions for the energy eigenvalues $E_{n,l\text{}}$ yield quite accurate results for a wide range of $n,\ell$ in the limit of very weak screening, the results become gradually worse as the strength $b$ and the screening coefficient $\delta$ increase. This is because that the expansion parameter is not sufficiently small enough to guarantee the convergence of the expansion series for the energy levels.Comment: 25 page

Mass Spectra of Heavy Quarkonia and B_{c} Decay Constant for Static Scalar-Vector Interactions with Relativistic Kinematics

We reproduce masses of the self-conjugate and non-self-conjugate mesons in the context of the spinless Salpeter equation taking into account the relativistic kinematics and the quark spins. The hyperfine splittings for the ${\rm 2S}$ charmonium and ${\rm 1S}$ bottomonium are also calculated. Further, the pseudoscalar and vector decay constants of the $B_{c}$ meson and the unperturbed radial wave function at the origin are also calculated. We have obtained a local equation with a complete relativistic corrections to a class of three attractive static interaction potentials of the general form $V(r)=-Ar^{-\beta}+\kappa r^{\beta}+V_{0},$ with $\beta =1,1/2,~3/4$ decomposed into scalar and vector parts in the form $V_{V}(r)=-Ar^{-\beta }+(1-\epsilon)\kappa r^{\beta}$ and $V_{S}(r)=\epsilon \kappa r^{\beta }+V_{0};$ where $0\leq \epsilon \leq 1.$ We have used the shifted large-N-expansion technique (SLNET) to solve the reduced equation for the scalar $(\epsilon =1),$ equal mixture of scalar-vector $(\epsilon =1/2),$ and vector $(\epsilon =0)$ confinement interaction kernels. The energy eigenvalues are carried out up to the third order approximation.Comment: 35 page