3,636 research outputs found
Search for three alpha states around an O core in Si
We investigate the existence of weakly coupled gas-like states comprised of
three particles around an O core in Si. We calculate the
excited states in Si using the multi-configuration mixing method based
on the O + 3 cluster model. We also include the O +
C and Mg + basis wave functions prepared by the
generator coordinate method. To identify the gas-like states, we calculate the
isoscalar monopole transition strengths and the overlap of the obtained states
with the geometrical cluster wave function and the
Tohsaki-Horiuchi-Schuck-R\"{o}pke (THSR) wave function. The results show that
the obtained fourth and twelfth states significantly overlap with the THSR wave
function. These two states clearly coexist with the O + C cluster
states, emerging at similar energies. The calculated isoscalar monopole
strengths between those two states are significantly large, indicating that the
states are members of the excitation mode. Furthermore, the calculated
root-mean-squared (RMS) radii for these states also suggest that a layer of
gas-like three particles could exist around the surface of the
O core, which can be described as a "two-dimensional gas" in the
intermediate state before the Hoyle-like three states emerge.Comment: 5 pages, 3 figure
Spectral gap of the totally asymmetric exclusion process at arbitrary filling
We calculate the spectral gap of the Markov matrix of the totally asymmetric
simple exclusion process (TASEP) on a ring of L sites with N particles. Our
derivation is simple and self-contained and extends a previous calculation that
was valid only for half-filling. We use a special property of the Bethe
equations for TASEP to reformulate them as a one-body problem. Our method is
closely related to the one used to derive exact large deviation functions of
the TASEP
On the elliptical flow in asymmetric collisions and nuclear equation of state
We here present the results of elliptical flow for the collision of different
asymmetric nuclei (10Ne20 +13 Al27, 18Ar40 +21 Sc45, 30Zn64 +28 Ni58, 36Kr86
+41 Nb93) by using the Quantum Molecular Dynamics (QMD) model. General features
of elliptical flow are investigated with the help of theoretical simulations.
The simulations are performed at different beam energies between 40 and 105
MeV/nucleon. A significant change can be seen from in-plane to out-of-plane
elliptical flow of different fragments with incident energy. A comparison with
experimental data is also made. Further, we predict, for the first time that,
elliptical flow for different kind of fragments follow power law dependence ?
C(Atot)? for asymmetric systems
On the Stereochemistry of the Cations in the Doping Block of Superconducting Copper-Oxides
Metal-oxygen complexes containing Cu,- Tl-, Hg-, Bi- and Pb-cations are
electronically active in superconducting copper-oxides by stabilizing single
phases with enhanced , whereas other metal-oxygen complexes deteriorate
copper-oxide superconductivity. Cu, Tl, Hg, Bi, Pb in their actual oxidation
states are closed shell or inert pair ions. Their electronic
configurations have a strong tendency to polarize the oxygen environment. The
closed shell ions with low lying
excitations form linear complexes through hybridization polarizing
the apical oxygens. Comparatively low excitation energies
distinguish from other closed shell
ions deteriorating copper-oxide superconductivity, {\it e.g.} .Comment: 5 pages, uses REVTEX. To be published in: J. Superconductivity, Proc.
Int. Workshop on "Phase Separation, Electronic Inhomogenities and Related
Mechanisms for High T_c Superconductors", Erice (Sicily) 9-15 July 199
A Heparin-Coated Circuit Reduces Complement Activation and the Release of Leukocyte Inflammatory Mediators During Extracorporeal Circulation in a Rabbit
Heparin coating modifies complement activation during extracorporeal circulation much more effcclively than systemically administered heparin. This rabbit study was undertaken to address possible mechanisms responsible for this difference. We evaluated the effect of heparin coating on complement activation and subsequently the release of leukocyte inflammatory mediators during extracorporeal circulation through a simplified circuit. We found in the heparin-coated group a significantly reduced complement hemolytic activity (CH 50 ), remaining higher leukocyte numbers, significantly decreased release of -glucuronidase, and most strikingly a complete prevention of tumor necrosis factor (TNF) formation. The significantly reduced CH 50 activity in the heparin-coated groups indicates the reduction of one or more native classical complement products. This could be explained by the absorption of complement components by the circuit, which results in reduced activity of the complement cascade. We conclude therefore that heparin coating reduces complement activation and consequently reduces the release of leukocyte inflammatory mediators.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73454/1/j.1525-1594.1992.tb00533.x.pd
Nitrogen addition alters composition, diversity, and functioning of microbial communities in mangrove soils : an incubation experiment
Mangrove ecosystems are important for carbon storage due to their high productivity and low decomposition rates. Waterways have experienced increased nutrient loads as a result of anthropogenic activities and it is unclear how this may affect carbon and nutrient cycles in downstream mangroves that receive these nutrient-rich waters. Using a laboratory-based incubation experiment, this study aimed to assess the effects of nutrient addition on the diversity and structure of mangrove soil bacterial communities, as well as biomass and activity of the soil microbial community, under different oxygen conditions. Bacterial community diversity and composition was characterised using 16S rRNA gene sequencing and microbial activity was examined through the measurement of microbial respiration and the activities of enzymes associated with organic matter decomposition. Nitrogen addition caused clear shifts in bacterial community composition, with decreases in bacterial diversity and the abundance of sulfate-reducing bacteria. Microbial biomass also decreased with nitrogen addition under reduced oxygen incubations. Changes in bacterial community structure were accompanied by changes in the activity of some enzymes involved in carbon, nitrogen and phosphorus cycling. Under reduced oxygen conditions, nitrogen addition resulted in a significant increase in the microbial metabolic quotient but no accompanying change in microbial respiration, which was explained by a decrease in microbial biomass. The findings of this study indicate that nitrogen loading has potential implications for microbial communities and carbon and nutrient cycling in mangrove environments that warrant further investigation under field conditions
Dependency Relationships within the Fission Yeast Polarity Network
The ability to regulate polarised cell growth is crucial to maintain the viability
of cells. Growth is modulated to facilitate essential cell functions and respond
to the external environment. Failure to do so can lead to numerous
developmental and disease states including cancer. We have undertaken a
detailed analysis of the regulatory interplay between molecules involved in the
regulation and maintenance of polarised cell growth within fission yeast.
Internally controlled live cell imaging was used to examine interactions
between 10 key polarity proteins. Analysis reveals: interplay between the
microtubule and actin cytoskeletons; multiple novel dependency pathways
and feedback networks between groups of proteins. This study provides
important insights into the conserved regulation of polarised cell growth within
eukaryotes
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