Modern Geometry

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Effect of salts on the deadly amphibian chytrid fungus Batrachochytrium dendrobatidis

The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a parasitic fungus that infects and kills amphibians worldwide. Bd causes electrolyte imbalance by destroying the keratin in the skin and causes cardiac arrest. Past studies have shown that Bd growth and motility can be inhibited by increased NaCl concentrations. In most studies, NaCl is the only type of salt used but Bd is exposed to other types of salts. In North American wetlands, runoff from road salts during winter and spring when Bd hosts (amphibians) often experience high levels of infection prevalence. This study investigated how different road salts at various concentrations affect the growth and motility of Bd. We predict that Bd growth will be inhibited more by road salts that contain more de-icing chemicals such as CaCl2 and that Bd growth will be the greatest in salts that are more environmentally friendly, such as Beet salt. Bd was reared in NaCl, CaCl2, and Beet salt at concentrations of 0.5, 1.0, 1.5, and 2.0 ppt. Growth was then quantified through counting and measuring of the area of growth and compared across treatments. Bd growth is greater in the absence of any salt than in the presence of either Beet salt, CaCl2, or NaCl. Bd growth at 14C was greater than at 22C. Our findings suggest several types of roads salts may have negative effects on Bd life history traits that could translate to lower infections in amphibians. Future studies should explore how road salts affect amphibians exposed to road salts, and how infection dynamics change when both host and pathogen are in the presence of these salts

Comparison of Muscle Activation During an Overhead Pres: Kettlebell v. Dumbbell

Please refer to the pdf version of the abstract located adjacent to the title

Magneto-x-ray effects in transition-metal alloys

We present a theory that combines the relativistic spin-polarized version of the Koringa-Kohn-Rostoker coherent-potential approximation theory and the macroscopic theory of magneto-optical effects enabling us to calculate magneto-x-ray effects from first principles. The theory is illustrated by calculation of Faraday and Kerr rotations and ellipticities for transition-metal alloys

Wavelength Tunability of Ion-bombardment Induced Ripples on Sapphire

A study of ripple formation on sapphire surfaces by 300-2000 eV Ar+ ion bombardment is presented. Surface characterization by in-situ synchrotron grazing incidence small angle x-ray scattering and ex-situ atomic force microscopy is performed in order to study the wavelength of ripples formed on sapphire (0001) surfaces. We find that the wavelength can be varied over a remarkably wide range-nearly two orders of magnitude-by changing the ion incidence angle. Within the linear theory regime, the ion induced viscous flow smoothing mechanism explains the general trends of the ripple wavelength at low temperature and incidence angles larger than 30. In this model, relaxation is confined to a few-nm thick damaged surface layer. The behavior at high temperature suggests relaxation by surface diffusion. However, strong smoothing is inferred from the observed ripple wavelength near normal incidence, which is not consistent with either surface diffusion or viscous flow relaxation.Comment: Revtex4, 19 pages, 10 figures with JPEG forma