5,166 research outputs found
THE UTILIZATION OF ACETATE BY NEOCOSMOSPORA VASINFECTA
Mycelium of Neocosmospora vasinfecta , harvested during active growth, was incubated for up to 10 minutes in dilute solutions of [1- 14 C]acetate or [2- 14 C]acetate. Radioactivity in the respiratory CO 2 and in identifiable compounds extracted from the mycelium was measured. Closely similar results were obtained with both [1- 14 C]acetate and [2- 14 C]acetate except for the loss of radioactivity to CO 2 , which took place much more rapidly from the [1- 14 C]acetate. Water-soluble compounds accounted for over 80% of the radioactivity of the mycelium. With incubation periods of up to 2.5 minutes, most of the radioactivity in the water-soluble material was associated with organic acids, whereas with longer incubation, the label in basic compounds predominated, Glutamate was consistently the most heavily labelled basic compound, with small amounts of radioactivity in glutamine and aspartic acid. Radioactivity in the organic acid fraction was practically confined to citric acid after 2.5 minutes incubation; succinic, malic and other acids were significantly labelled after 10 minutes. The specific activities of these acids after 10 minutes decreased in the order citrate, succinate, malate, suggesting their involvement in the tricarboxylic acid cycle. The results are discussed in relation to the importance of the tricarboxylic acid cycle in acetate utilization, nitrogen assimilation and respiration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66212/1/j.1469-8137.1966.tb05411.x.pd
Ambiguities of neutrino(antineutrino) scattering on the nucleon due to the uncertainties of relevant strangeness form factors
Strange quark contributions to neutrino(antineutrino) scattering are
investigated on the nucleon level in the quasi-elastic region. The incident
energy range between 500 MeV and 1.0 GeV is used for the scattering. All of the
physical observable by the scattering are investigated within available
experimental and theoretical results for the strangeness form factors of the
nucleon. In specific, a newly combined data of parity violating electron
scattering and neutrino scattering is exploited. Feasible quantities to be
explored for the strangeness contents are discussed for the application to
neutrino-nucleus scattering.Comment: 17 pages, 7 figures, submit to J. Phys.
Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair
The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway
The chemical potential for the inhomogeneous electron liquid in terms of its kinetic and potential parts with special consideration of the surface pote ntial step and BCS-BEC crossover
The chemical potential of a many-body system is valuable since it
carries fingerprints of phase changes. Here, we summarize results for for
a thre e-dimensional electron liquid in terms of average kinetic and potential
energie s per particle. The difference between and the energy per
particle is fou nd to be exactly the electrostatic potential step at the
surface. We also prese nt calculations for an integrable one-dimensional
many-body system with delta f unction interactions, exhibiting a BCS-BEC
crossover. It is shown that in the B CS regime the chemical potential can be
expressed solely in terms of the ground -state energy per particle. A brief
discussion is also included of the strong c oupling BEC limit.Comment: 4 pages 3 figure
Mutation Testing as a Safety Net for Test Code Refactoring
Refactoring is an activity that improves the internal structure of the code
without altering its external behavior. When performed on the production code,
the tests can be used to verify that the external behavior of the production
code is preserved. However, when the refactoring is performed on test code,
there is no safety net that assures that the external behavior of the test code
is preserved. In this paper, we propose to adopt mutation testing as a means to
verify if the behavior of the test code is preserved after refactoring.
Moreover, we also show how this approach can be used to identify the part of
the test code which is improperly refactored
Molecular evidence for horizontal transmission of chelonid alphaherpesvirus 5 at green turtle (Chelonia mydas) foraging grounds in Queensland, Australia
Fibropapillomatosis (FP) is a marine turtle disease recognised by benign tumours on the skin, eyes, shell, oral cavity and/or viscera. Despite being a globally distributed disease that affects an endangered species, research on FP and its likely causative agent chelonid alphaherpesvirus 5 (ChHV5) in Australia is limited. Here we present improved molecular assays developed for detection of ChHV5, in combination with a robust molecular and phylogenetic analysis of ChHV5 variants. This approach utilised a multi-gene assay to detect ChHV5 in all FP tumors sampled from 62 marine turtles found at six foraging grounds along the Great Barrier Reef. Six distinct variants of ChHV5 were identified and the distribution of these variants was associated with host foraging ground. Conversely, no association between host genetic origin and ChHV5 viral variant was found. Together this evidence supports the hypothesis that marine turtles undergo horizontal transmission of ChHV5 at foraging grounds and are unlikely to be contracting the disease at rookeries, either during mating or vertically from parent to offspring
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