2,434 research outputs found
Spatio-temporal patterns of crab fisheries in the main bays of Guangdong Province, China
Using a semi-balloon otter trawl, crab fisheries in the main bays of Guangdong Province, China, were carried out seasonally . A total of 70 species were found, all belonging to the South China Sea Faunal sub region in the tropical India-West-Pacific Faunal Region. The clustering and nMDS ordination analysis revealed the existence of three groups. Group 1 included Hailing Bay and four bays to its east where typical species were Portunus sanguinolentus, P. pelagicus and Charybdis feriatus. Group 2 included Shuidong Bay and Leizhou Bay where typical species were P. sanguinolentus, P. pelagicus and P. hastatoides. Group 3 was Liusha Bay where typical species were C. feriatus, C. vadorum and C. truncate. The spatial and temporal variations of crab fisheries were mainly associated with characteristics of the sediment, seasonal changes and their own biological characteristics, but not significantly with water depth, temperature, salinity, and the âmid-summer fishing moratoriumâ conservation measure
Comparison of SIVmac239(352â382) and SIVsmmPBj41(360â390) enterotoxic synthetic peptides
AbstractTo characterize the active domain of the simian immunodeficiency virus (SIV) surface unit (SU) enterotoxin, peptides corresponding to the V3 loop of SIVmac239 (SIVmac) and SIVsmmPBj41 (SIVpbj) were synthesized and examined for enterotoxic activity, α-helical structure, and interaction(s) with model membranes. SIVmac and SIVpbj induced a dose-dependent diarrhea in 6â8-day-old mouse pups similar to full-length SU. The peptides mobilized [Ca2+]i in HT-29 cells with distinct oscillations and elevated inositol triphosphate levels. Circular dichroism analyses showed the peptides were predominantly random coil in buffer, but increased in α-helical content when placed in a hydrophobic environment or with cholesterol-containing membrane vesicles that are rich in anionic phospholipids. None of the peptides underwent significant secondary structural changes in the presence of neutral vesicles indicating ionic interactions were important. These data show that the SIV SU enterotoxic domain localizes in part to the V3 loop region and interacts with anionic membrane domains on the host cell surface
CMB Power Spectrum from Noncommutative Spacetime
Very recent CMB data of WMAP offers an opportunity to test inflation models,
in particular, the running of spectral index is quite new and can be used to
rule out some models. We show that an noncommutative spacetime inflation model
gives a good explanation of these new results. In fitting the data, we also
obtain a relationship between the noncommutative parameter (string scale) and
the ending time of inflation.Comment: 8 pages, 2 figures; v2: refs. added and minor corrections; v3:
further minor correctio
Tracing Ghost Cavities with Low Frequency Radio Observations
We present X-ray and multi-frequency radio observations of the central radio
sources in several X-ray cavity systems. We show that targeted radio
observations are key to determining if the lobes are being actively fed by the
central AGN. Low frequency observations provide a unique way to study both the
lifecycle of the central radio source as well as its energy input into the ICM
over several outburst episodes.Comment: 6 pages, 4 figures, To appear in the Proceedings of "Heating vs.
Cooling in Galaxies and Clusters of Galaxies", eds. H. Boehringer, P.
Schuecker, G. W. Pratt & A. Finoguenov (ESO Astrophysics Symposia,
Springer-Verlag), Garching (Germany), August 200
Study of the Anti-Proliferative Activity of 5-Substituted 4,7-Dimethoxy-1,3-Benzodioxole Derivatives of SY-1 from Antrodia camphorata on Human COLO 205 Colon Cancer Cells
A set of 10 4,7-dimethoxy-1,3-benzodioxole derivatives based on a lead compound previously discovered by our group, SY-1, which was isolated from Antrodia camphorata, were evaluated for their in vitro inhibitory activity on human colorectal carcinoma cells (COLO 205). Structure-activity relationship studies of the 10 compounds indicated the importance of the chain length of the alkyl group at the 5-position, and the 2-propenyl substituent named âapioleâ exhibited the most potent inhibitory activity. In the present study, we demonstrate that the SY-1 analogue âapioleâ decreased the proliferation of COLO 205 cells, but not that of normal human colonic epithelial cells (FHC). The G0/G1 cell cycle arrest induced by apiole (75â225âÎŒM) was associated with significantly increased levels of p53, p21 and p27 and decreased levels of cyclin D1. Concerning COLO 205 cell apoptosis, apiole (>150âÎŒM) treatment significantly increased the levels of cleaved caspases 3, 8, 9 and bax/bcl-2 ratio and induced ladder formation in DNA fragmentation assay and sub-G1 peak in flow cytometry analysis. These findings suggest that apiole can suppress COLO 205 cell growth; however, the detailed mechanisms of these processes require further investigation
Hamiltonian Formalism of the de-Sitter Invariant Special Relativity
Lagrangian of the Einstein's special relativity with universal parameter
() is invariant under Poincar\'e transformation which preserves
Lorentz metric . The has been extended to be
one which is invariant under de Sitter transformation that preserves so called
Beltrami metric . There are two universal parameters and in
this Special Relativity (denote it as ). The
Lagrangian-Hamiltonian formulism of is formulated in this
paper. The canonic energy, canonic momenta, and 10 Noether charges
corresponding to the space-time's de Sitter symmetry are derived. The canonical
quantization of the mechanics for -free particle is
performed. The physics related to it is discussed.Comment: 24 pages, no figur
Diagnostic for Dilaton Dark Energy
diagnostic can differentiate between different models of dark energy
without the accurate current value of matter density. We apply this geometric
diagnostic to dilaton dark energy(DDE) model and differentiate DDE model from
LCDM. We also investigate the influence of coupled parameter on the
evolutive behavior of with respect to redshift . According to the
numerical result of , we get the current value of equation of state
=-0.952 which fits the WMAP5+BAO+SN very well.Comment: 6 pages and 6 figures
Electron correlation energy in confined two-electron systems
Radial, angular and total correlation energies are calculated for four
two-electron systems with atomic numbers Z=0-3 confined within an impenetrable
sphere of radius R. We report accurate results for the non-relativistic,
restricted Hartree-Fock and radial limit energies over a range of confinement
radii from 0.05 - 10 a0. At small R, the correlation energies approach limiting
values that are independent of Z while at intermediate R, systems with Z > 1
exhibit a characteristic maximum in the correlation energy resulting from an
increase in the angular correlation energy which is offset by a decrease in the
radial correlation energy
The Subdominant Curvaton
We present a systematic study of the amplitude of the primordial perturbation
in curvaton models with self-interactions, treating both renormalizable and
non-renormalizable interactions. In particular, we consider the possibility
that the curvaton energy density is subdominant at the time of the curvaton
decay. We find that large regions in the parameter space give rise to the
observed amplitude of primordial perturbation even for non-renormalizable
curvaton potentials, for which the curvaton energy density dilutes fast. At the
time of its decay, the curvaton energy density may typically be subdominant by
a relative factor of 10^-3 and still produce the observed perturbation. Field
dynamics turns out to be highly non-trivial, and for non-renormalizable
potentials and certain regions of the parameter space we observe a
non-monotonous relation between the final curvature perturbation and the
initial curvaton value. In those cases, the time evolution of the primordial
perturbation also displays an oscillatory behaviour before the curvaton decay.Comment: Acknowledgments of financial support added, no further change
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