47 research outputs found
Effective hadron masses and couplings in nuclear matter and incompressibility
The role of effective hadron masses and effective couplings in nuclear matter
is studied using a generalized effective Lagrangian for sigma-omega model. A
simple relation among the effective masses, the effective couplings and the
incompressibility K is derived. Using the relation, it is found that the
effective repulsive and the effective attractive forces are almost canceled to
each other at the normal density. Inversely, if this cancellation is almost
complete, K should be 250-350MeV.Comment: 13 pages of text, 16 figure
Effective meson masses, effective meson-nucleon couplings and neutron star radii
Using the generalized mean field theory, we have studied the relation among
the effective meson masses, the effective meson-nucleon couplings and the
equation of state (EOS) in asymmetric nuclear matter. If the effective
omega-meson mass becomes smaller at high density, the EOS becomes stiffer.
However, if we require that the omega-meson mean field is proportional to the
baryon density, the effective omega-nucleon coupling automatically becomes
smaller at the same time as the effective omega-meson mass becomes smaller.
Consequently, the EOS becomes softer. A similar relation is found for the
effective rho-meson mass and the effective rho-nucleon coupling. We have also
studied the relation among the effective meson masses, the effective
meson-nucleon couplings and a radius R of a neutron star. The R depends
somewhat on the value of the effective omega-meson mass and the effective
omega-nucleon coupling.Comment: 29pages, 24 figure
Identification of the Transcriptional Regulator NcrB in the Nickel Resistance Determinant of Leptospirillum ferriphilum UBK03
The nickel resistance determinant ncrABCY was identified in Leptospirillum ferriphilum UBK03. Within this operon, ncrA and ncrC encode two membrane proteins that form an efflux system, and ncrB encodes NcrB, which belongs to an uncharacterized family (DUF156) of proteins. How this determinant is regulated remains unknown. Our data indicate that expression of the nickel resistance determinant is induced by nickel. The promoter of ncrA, designated pncrA, was cloned into the promoter probe vector pPR9TT, and co-transformed with either a wild-type or mutant nickel resistance determinant. The results revealed that ncrB encoded a transcriptional regulator that could regulate the expression of ncrA, ncrB, and ncrC. A GC-rich inverted repeat sequence was identified in the promoter pncrA. Electrophoretic mobility shift assays (EMSAs) and footprinting assays showed that purified NcrB could specifically bind to the inverted repeat sequence of pncrA in vitro; this was confirmed by bacterial one-hybrid analysis. Moreover, this binding was inhibited in the presence of nickel ions. Thus, we classified NcrB as a transcriptional regulator that recognizes the inverted repeat sequence binding motif to regulate the expression of the key nickel resistance gene, ncrA
Phytoextraction of soil cadmium and zinc by microbes-inoculated Indian mustard ( Brassica juncea
Solubility and Accumulation of Metals in Chinese Brake Fern, Vetiver and Rostrate Sesbania Using Chelating Agents
Protective Effect of Dietary Tomato against Endothelial Dysfunction in Hypercholesterolemic Mice
Elemental concentrations in skin and internal tissues of Commersonâs dolphins (Cephalorhynchus commersonii) from subantarctic waters
The skin of cetaceans is the most accessibletissue, and its sampling has been proposed as a noninvasivemethod to evaluate trace element concentrations in free-rangingpopulations. In the present work, concentrations ofessential (Cl, Na, K, Mg, Fe, Zn, Mn and Co), nonessential(As and Ag), and of unknown essentiality (Br, Rb and Cs)elements were determined in the skin from nine by-caughtCommersonÂŽs dolphins (Cephalorhynchus commersonii)from Tierra del Fuego, Argentina. Skin correlations withinternal tissues (lung, liver, kidney and muscle) wereassessed to evaluate how the skin represents internal elementconcentration for monitoring purposes. Elementalcontents were analyzed by instrumental neutron activationanalysis (INAA). Regarding tissue distribution, skin hadthe highest concentration of Zn being two orders of magnitudehigher than internal tissues, while other elementssuch as Co and Rb had similar concentrations among tissues.High mean concentrations of Cl, Na, Mg, Br and Mnwere observed in the lung and liver. Our results support theuse of skin to evaluate Fe, Br and Rb concentrations ininternal tissues for biomonitoring purposes; however, otherelements did not show significant skin-to-tissue correlations.Overall, toxic element levels were far below concentrationsfound to cause harm in marine vertebrates. Thisstudy provided baseline data on elemental concentrationsin tissues of CommersonÂŽs dolphins in subantarctic watersfrom the South Atlantic Ocean.Fil: CĂĄceres Saez, Iris. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Museo AcatushĂșn de Aves y MamĂferos Marinos Australes; ArgentinaFil: Ribeiro Guevara, Sergio. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Ărea de EnergĂa Nuclear. Unidad de Actividad de IngenierĂa Nuclear. Laboratorio de AnĂĄlisis por ActivaciĂłn NeutrĂłica; ArgentinaFil: Prosser Goodall, Rae Natalie. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Austral de Investigaciones CientĂficas; Argentina. Museo AcatushĂșn de Aves y MamĂferos Marinos Australes; ArgentinaFil: Dellabianca, Natalia Andrea. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Austral de Investigaciones CientĂficas; Argentina. Museo AcatushĂșn de Aves y MamĂferos Marinos Australes; ArgentinaFil: Cappozzo, Humberto Luis. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. FundaciĂłn de Historia Natural FĂ©lix de Azara; Argentina. Universidad MaimĂłnides. Ărea de Investigaciones BiomĂ©dicas y BiotecnolĂłgicas. Centro de Estudios BiomĂ©dicos, BiotecnolĂłgicos, Ambientales y de DiagnĂłstico; Argentin
GECAF: a framework for developing context-aware pervasive systems
Context-aware systems differ in the way they interact with users, the way they interpret the context of their entities and the actions they take. Each system (or system type) is developed in its own way with no common architecture currently available. This fact makes the development of every context aware system a challenge. To address this issue, a generic and extensible framework is needed so that it can be used for developing various systems. This paper proposes a generic framework that uses the Pipe-and-Filter software architectural style, which is a well-known style, allowing developers to create new systems by arranging existing components into various arrangements to meet the systemâs requirements. The paper also analyses the state of the art architectures to study their functionality and architectural organisation. The analysis was then used as a basis for comparing and evaluating the proposed framework