521 research outputs found
WCPFC-SC9-2013/SA-IP-06
Analyses of tagging data for tropical tunas, with implications for the structure of WCPO bigeye stock assessment
SCIENTIFIC COMMITTEE SIXTH REGULAR SESSION ANALYSES OF JAPANESE LONGLINE OPERATIONAL CATCH AND EFFORT FOR BIGEYE TUNA IN THE WCPO
Consultant, Secretariat of the Pacific Community. Analyses of Japanese longline operational catch and effort for bigeye tuna in the WCP
Determinants of Reactivity and Selectivity in Soluble Epoxide Hydrolase from Quantum Mechanics/Molecular Mechanics Modeling
Biological data and model development for management of longfinned eels
Objectives:
1. Estimate population parameters required for a management model. These include survival, density, age structure, growth, age and size at maturity and at recruitment to the adult eel fishery. Estimate their variability among individuals in a range of habitats.
2. Develop a management population dynamics model and use it to investigate management options.
3. Establish baseline data and sustainability indicators for long-term monitoring.
4. Assess the applicability of the above techniques to other eel fisheries in Australia, in collaboration with NSW. Distribute developed tools via the Australia and New Zealand Eel Reference Group
Biological data and model development for management of longfinned eels
Objectives:
1. Estimate population parameters required for a management model. These include survival, density, age structure, growth, age and size at maturity and at recruitment to the adult eel fishery. Estimate their variability among individuals in a range of habitats.
2. Develop a management population dynamics model and use it to investigate management options.
3. Establish baseline data and sustainability indicators for long-term monitoring.
4. Assess the applicability of the above techniques to other eel fisheries in Australia, in collaboration with NSW. Distribute developed tools via the Australia and New Zealand Eel Reference Group
Application of the comprehensive set of heterozygous yeast deletion mutants to elucidate the molecular basis of cellular chromium toxicity.
BACKGROUND: The serious biological consequences of metal toxicity are well documented, but the key modes of action of most metals are unknown. To help unravel molecular mechanisms underlying the action of chromium, a metal of major toxicological importance, we grew over 6,000 heterozygous yeast mutants in competition in the presence of chromium. Microarray-based screens of these heterozygotes are truly genome-wide as they include both essential and non-essential genes. RESULTS: The screening data indicated that proteasomal (protein degradation) activity is crucial for cellular chromium (Cr) resistance. Further investigations showed that Cr causes the accumulation of insoluble and toxic protein aggregates, which predominantly arise from proteins synthesised during Cr exposure. A protein-synthesis defect provoked by Cr was identified as mRNA mistranslation, which was oxygen-dependent. Moreover, Cr exhibited synergistic toxicity with a ribosome-targeting drug (paromomycin) that is known to act via mistranslation, while manipulation of translational accuracy modulated Cr toxicity. CONCLUSION: The datasets from the heterozygote screen represent an important public resource that may be exploited to discover the toxic mechanisms of chromium. That potential was validated here with the demonstration that mRNA mistranslation is a primary cause of cellular Cr toxicity.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Simulated void galaxies in the standard cold dark matter model
We analyze a (120 h^{-1} Mpc)^3 adaptive mesh refinement hydrodynamic
simulation that contains a higher-resolution 31 x 31 x 35 h^{-3} Mpc subvolume
centered on a ~30 Mpc diameter void. Our detailed ~1 kpc resolution allows us
to identify 1300 galaxies within this void to a limiting halo mass of ~10^{10}
M_sun. Nearly 1000 galaxies are found to be in underdense regions, with 300
galaxies residing in regions less than half the mean density of the simulation
volume. We construct mock observations of the stellar and gas properties of
these systems, and reproduce the range of colors and luminosities observed in
the SDSS for nearby (z < 0.03) galaxies. We find no trends with density for the
most luminous (M_r
-16), though they are less reliably resolved, typically appear bluer, with
higher rates of star formation and specific star formation and lower mean
stellar ages than galaxies in average density environments. We find a
significant population of low luminosity (M_r ~ -14) dwarf galaxies that is
preferentially located in low density regions and specifically in the void
center. This population may help to reduce, but not remove, the discrepancy
between the predicted and observed number of void galaxies.Comment: 23 pages, 14 figures, submitted to Ap
Genome-Wide Analysis of the Effects of Heat Shock on a Saccharomyces cerevisiae Mutant With a Constitutively Activated cAMP-Dependent Pathway
We have used DNA microarray technology and 2-D gel electrophoresis combined with
mass spectrometry to investigate the effects of a drastic heat shock from 30℃ to 50℃
on a genome-wide scale. This experimental condition is used to differentiate between
wild-type cells and those with a constitutively active cAMP-dependent pathway in
Saccharomyces cerevisiae. Whilst more than 50% of the former survive this shock,
almost all of the latter lose viability. We compared the transcriptomes of the wildtype
and a mutant strain deleted for the gene PDE2, encoding the high-affinity cAMP
phosphodiesterase before and after heat shock treatment. We also compared the two
heat-shocked samples with one another, allowing us to determine the changes that
occur in the pde2Δ mutant which cause such a dramatic loss of viability after heat
shock. Several genes involved in ergosterol biosynthesis and carbon source utilization
had altered expression levels, suggesting that these processes might be potential
factors in heat shock survival. These predictions and also the effect of the different
phases of the cell cycle were confirmed by biochemical and phenotypic analyses. 146
genes of previously unknown function were identified amongst the genes with altered
expression levels and deletion mutants in 13 of these genes were found to be highly
sensitive to heat shock. Differences in response to heat shock were also observed at
the level of the proteome, with a higher level of protein degradation in the mutant, as
revealed by comparing 2-D gels of wild-type and mutant heat-shocked samples and
mass spectrometry analysis of the differentially produced proteins
Triphenylarsonium-functionalised gold nanoparticles: potential nanocarriers for intracellular therapeutics.
This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.Two new triphenylarsonium alkylthiolate precursors, a thiosulfate zwitterion and a thioacetate salt, have been structurally characterised and their cytotoxicity evaluated against PC3 cells. The arsonium compounds have been used to prepare gold nanoparticles decorated with triphenylarsonium groups.Sheffield Hallam University and Indian Institute of Science (NL)
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