Leech Parasitism of the Gulf Coast Box Turtle, Terrapene carolina major (Testudines:Emydidae) in Mississippi, USA

Ten leeches were collected from a Gulf Coast box turtle, Terrapene carolina major, found crossing a road in Gulfport, Harrison County, Mississippi, USA. Eight of the leeches were identified as Placobdella multilineata and 2 were identified as Helobdella europaea. This represents the second vouchered report of leeches from a box turtle. Helobdella europaea is reported for the first time associated with a turtle and for the second time from the New World

Sexual Dimorphism and Intersexual Differences in Resource Allocations of a Dioecious Shrub, Lindera melissifolia (Walt.) Blume

Morphometric data were gathered to make intersexual comparisons on the morphology and reproductive resource allocation patterns of the rare, dioecious shrub, Lindera melissifolia. Females produced significantly fewer flowers and leaves than did males. No other significant differences could be detected in morphology. Female clones exhibit low area coverage and low stem density, which suggests higher costs of reproduction. If this is the case, the deficits produced in resource allocations directed toward sexual reproduction seem to result in increased mortality and/or reduced vegetative reproduction

Leeches (Annelida: Hirudinida) of Northern Arkansas

Twenty-one lotic and lentic environments throughout central and northern Arkansas were surveyed for the presence of leeches during June 2004 and April, July - October 2005. Fourteen species of leeches {Helobdella elongata, Helobdella papillata, Helobdella stagnalis, Placobdella cryptobranchii, Placobdella multilineata, Placobdella ornata, Placobdella papillifera, Placobdella parasitica, Placobdella phaler a, Placobdella picta, Haemopis marmorata, Erpobdella fervida, Erpobdella microstoma, and Erpobdella punctata) representing 3 families were collected. Five species (H. elongata, P. cryptobranchii, P. multilineata, H. marmorata, and E. fervida) are reported from Arkansas for the first time. The natural history of the 22 species of leeches now known from Arkansas is reviewed

In-situ X-ray-absorption Spectroscopy Study of Hydrogen Absorption by Nickel-Magnesium Thin Films

Structural and electronic properties of co-sputtered Ni-Mg thin films with varying Ni to Mg ratio were studied by in-situ x-ray absorption spectroscopy in the Ni L-edge and Mg K-edge regions. Co-deposition of the metals led to increased disorder and decreased coordination around Ni and Mg compared to pure metal films. Exposure of the metallic films to hydrogen resulted in formation of hydrides and increased disorder. The presence of hydrogen as a near neighbor around Mg caused a drastic reduction in the intensities of multiple scattering resonances at higher energies. The optical switching behavior and changes in the x-ray spectra varied with Ni to Mg atomic ratio. Pure Mg films with Pd overlayers were converted to MgH2: the H atoms occupy regular sites as in bulk MgH2. Although optical switching was slow in the absence of Ni, the amount of H2 absorption was large. Incorporation of Ni in Mg films led to an increase in the speed of optical switching but decreased maximum transparency. Significant shifts in the Ni L3 and L2 peaks are consistent with strong interaction with hydrogen in the mixed films

E+A Galaxies and the Formation of Early Type Galaxies at z~0

We present HST/WFPC2 observations of the five bluest E+A galaxies (z~0.1) in the Zabludoff et al. sample to study whether their detailed morphologies are consistent with late-to-early type evolution and to determine what drives that evolution. The morphologies of four galaxies are disturbed, indicating that a galaxy-galaxy merger is at least one mechanism that leads to the E+A phase. Two-dimensional image fitting shows that the E+As are generally bulge-dominated systems, even though at least two E+As may have underlying disks. In the Fundamental Plane, E+As stand apart from the E/S0s mainly due to their high effective surface brightness. Fading of the young stellar population and the corresponding increase in their effective radii will cause these galaxies to migrate toward the locus of E/S0s. E+As have profiles qualitatively like those of normal power-law early-type galaxies, but have higher surface brightnesses. This result provides the first direct evidence supporting the hypothesis that power-law ellipticals form via gas-rich mergers. In total, at least four E+As are morphologically consistent with early-type galaxies. We detect compact sources, possibly young star clusters, associated with the galaxies. These sources are much brighter (M_R ~ -13) than Galactic globular clusters, have luminosities consistent with the brightest clusters in nearby starburst galaxies, and have blue colors consistent with the ages estimated from the E+A galaxy spectra (several 10^8 yr). Further study of such young star cluster candidates might provide the elusive chronometer needed to break the age/burst-strength degeneracy for these post-merger galaxies.Comment: 30 pages, 11 figures, accepted for publication in Ap