Meson decay in an independent quark model

Leptonic decay widths and leptonic decay constants of light vector mesons and weak leptonic decay widths and weak decay constants of light and heavy pseudoscalar mesons have been studied in a field- theoretic framework based on the independent quark model with a scalar- vector power-law potential. The results are in very good agreement with the experimental data.Comment: 13 page

Synthesis and characterizations of BNT-BT and BNT-KNN ceramics

BNT-BT [(0.93Bi0.5Na0.5)TiO3- 0.07Ba-TiO3 ] and BNT-KNN [(0.93Bi0.5Na0.5)TiO3 – 0.07K 0.5 Na 0.5 NbO3 ] was prepared by the solid state route using microwave process. The prepared sample was calcined at 900°C for 10 minutes by microwave process for both BNT-BT and BNT-KNN. Then the sample was characterized by different techniques, from XRD of the sample a single perovskite phase was confirmed. All the samples were sintered using the microwave sintering method at 1150°C for 30 minutes with a heating rate of 40°/min. The FE-SEM micrograph images of the samples showed dense microstructure and uniform grain size. Then the study of dielectric properties of the sample was done. The P-E loop measurement confirms the ferroelectric nature of the sample

Transition metal clusters containing ferrocenyl diphosphine

ABSTRACT The ligating ability of 1,1-bis(diphenylphosphino)ferrocene (dppf) enables its extensive coordination chemistry to transition metals. To study the various ligating modes of dppf with chalcogenide transition metal clusters, three new compounds were synthesised and their mode of bonding has been studied. [Fe3Te2(CO)9{(PPh2)(C5H4)Fe(C5H4)(PPh2)}] (Te2Red3) was synthesised in room temperature , 31 P NMR spectra shows a singlet denoting dppf adopts a chelating mode of bonding, [Fe3Te2(CO)9{(PPh2)(C5H4)Fe(C5H4)(PPh2)}] (Te2Red1) was synthesised at 0o C and [Fe3Se2(CO)8(į1-dppf)] (Se2Black1) was synthesised at room temperature. From the 31 P NMR spectra it was found that one of the phosphorus was coordinated to the iron metal and the other phosphorus was hanging . The uncoordinated phosphorus was used for further cluster growth reactions with W(CO)5THF and the dppf ligand adopts inter-bridging mode of bonding in the compound [Fe3Se2(CO)8dppfW(CO)5]

Origin, heterogeneity, and interconversion of noncanonical bistable switches from the positive feedback loops under dual signaling

Summary Designing new functional motifs with unique properties is an important objective in the realm of synthetic biology. We uncover emergent properties of positive feedback loops (PFLs) under dual input signaling using pseudo potential energy-based high-throughput bifurcation analysis. We show that under dual signaling a single PFL generates a variety of noncanonical bistable switches, with one or more bistable regions, due to fusion of multiple canonical bistable switches. Regulatory signs of the dual signaling must be coherent for mutual inhibition loop and incoherent for mutual activation loop of the PFL. Occurrence probabilities show that some of the noncanonical switches, such as isola and mushroom, are highly recurrent under random parameterization. Phase diagrams of the noncanonical switches reveal that feedback strengths of the PFL control the transition from one switch to another. Our calculations decipher the design principles of noncanonical bistable switches that originate from synthetically feasible simple PFL motifs under dual signaling

Protocol for potential energy-based bifurcation analysis, parameter searching, and phase diagram analysis of noncanonical bistable switches

We have explored the design principles of noncanonical bistable switches using high-throughput bifurcation analysis of positive feedback loops under dual signaling. Here, we present a protocol to carry out bifurcation analysis using pseudo-potential energy of the dynamical system. We also describe steps to perform automated parameter searching for canonical and noncanonical switches and multi-parameter phase diagram analysis of these switches. For complete details on the use and execution of this protocol, please refer to Das et al.

Role of S gene product of bacteriophage lambda in host cell lysis

Studies with the induced lysogens of λ S +R+, λS-R+, λS+R- and λS-R- phages have shown that while the S gene product is essential for the action of intracellular R gene product to release the periplasmic alkaline phosphatase in the presence of EDTA, the latter gene product can bring about this effect while acting on Escherichia coli cells from outside, in the absence of functional S gene product; chloroform, could help the intracellular R gene product in effecting bacterial lysis in the absence of S gene product. These result support the premise that the S gene product facilitates the R gene product in crossing the cytoplasmic membrane into the periplasmic space such that the latter can act on the peptidoglycan layer of the host cell thus causing both the release of alkaline phosphatase and cell lysis