Mechanism of the photovoltaic effects in 2-4 compounds Progress report, 1 Apr. - 30 Sep. 1968

Current gain mechanism in copper sulfide-cadmium sulfide diode upon photoexcitation in presence of reverse bia

Pathogenic Fungus Batrachochytrium Dendrobatidis in Marbled Water Frog Telmatobius Marmoratus: First Record From Lake Titicaca, Bolivia

The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians

Embedding initial data for black hole collisions

We discuss isometric embedding diagrams for the visualization of initial data for the problem of the head-on collision of two black holes. The problem of constructing the embedding diagrams is explicitly presented for the best studied initial data, the Misner geometry. We present a partial solution of the embedding diagrams and discuss issues related to completing the solution.Comment: (27pp text, 11 figures

Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

<p>Abstract</p> <p>Background</p> <p>The ascomycete fungus <it>Cercospora zeae-maydis </it>is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in <it>C. zeae-maydis </it>at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from <it>C. zeae-maydis </it>and evaluate their expression during vegetative, infectious, and reproductive growth.</p> <p>Results</p> <p>A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of <it>C. zeae-maydis</it>. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value ≤ 10^-05) to characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions and biological processes based on Gene Ontology (GO) classification. We identified numerous, previously undescribed genes with potential roles in photoreception, pathogenesis, and the regulation of development as well as <it>Zephyr</it>, a novel, actively transcribed transposable element. Differential expression of selected genes was demonstrated by real-time PCR, supporting their proposed roles in vegetative, infectious, and reproductive growth.</p> <p>Conclusion</p> <p>Novel genes that are potentially involved in regulating growth, development, and pathogenesis were identified in <it>C. zeae-maydis</it>, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of <it>Cercospora </it>and other groups of plant pathogenic fungi.</p

Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

<p>Abstract</p> <p>Background</p> <p>The ascomycete fungus <it>Cercospora zeae-maydis </it>is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in <it>C. zeae-maydis </it>at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from <it>C. zeae-maydis </it>and evaluate their expression during vegetative, infectious, and reproductive growth.</p> <p>Results</p> <p>A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of <it>C. zeae-maydis</it>. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value ≤ 10^-05) to characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions and biological processes based on Gene Ontology (GO) classification. We identified numerous, previously undescribed genes with potential roles in photoreception, pathogenesis, and the regulation of development as well as <it>Zephyr</it>, a novel, actively transcribed transposable element. Differential expression of selected genes was demonstrated by real-time PCR, supporting their proposed roles in vegetative, infectious, and reproductive growth.</p> <p>Conclusion</p> <p>Novel genes that are potentially involved in regulating growth, development, and pathogenesis were identified in <it>C. zeae-maydis</it>, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of <it>Cercospora </it>and other groups of plant pathogenic fungi.</p

Black hole collisions from Brill-Lindquist initial data: predictions of perturbation theory

The Misner initial value solution for two momentarily stationary black holes has been the focus of much numerical study. We report here analytic results for an astrophysically similar initial solution, that of Brill and Lindquist (BL). Results are given from perturbation theory for initially close holes and are compared with available numerical results. A comparison is made of the radiation generated from the BL and the Misner initial values, and the physical meaning is discussed.Comment: 11 pages, revtex3.0, 5 figure

Dissipative fluids out of hydrostatic equilibrium

In the context of the M\"{u}ller-Israel-Stewart second order phenomenological theory for dissipative fluids, we analyze the effects of thermal conduction and viscosity in a relativistic fluid, just after its departure from hydrostatic equilibrium, on a time scale of the order of relaxation times. Stability and causality conditions are contrasted with conditions for which the ''effective inertial mass'' vanishes.Comment: 21 pages, 1 postscript figure (LaTex 2.09 and epsfig.sty required) Submitted to Classical and Quantum Gravit

Slowing and cooling molecules and neutral atoms by time-varying electric field gradients

A method of slowing, accelerating, cooling, and bunching molecules and neutral atoms using time-varying electric field gradients is demonstrated with cesium atoms in a fountain. The effects are measured and found to be in agreement with calculation. Time-varying electric field gradient slowing and cooling is applicable to atoms that have large dipole polarizabilities, including atoms that are not amenable to laser slowing and cooling, to Rydberg atoms, and to molecules, especially polar molecules with large electric dipole moments. The possible applications of this method include slowing and cooling thermal beams of atoms and molecules, launching cold atoms from a trap into a fountain, and measuring atomic dipole polarizabilities.Comment: 13 pages, 10 figures. Scheduled for publication in Nov. 1 Phys. Rev.