Proton decay is examined within the framework of certain SO(10) models which have low dimension representations compatible with the recently found constraints coming from string theory, and which use the Dimopoulos-Wilczek mechanism to solve the doublet-triplet splitting problem. It is found that the mass parameter that controls proton decay rate is intimately related to the low energy data via...

Sodium/proton antiporters maintain intracellular pH and sodium levels. Detailed structures of antiporters with bound substrate ions are essential for understanding how they work. We have resolved the substrate ion in the dimeric, electroneutral sodium/proton antiporter PaNhaP from Pyrococcus abyssi at 3.2 Å, and have determined its structure in two different conformations at pH 8 and pH 4. The ...

the elementary reaction of kaon exclusive electroproduction on protons has been studied ina broad kinematical range. data for the calculation of the form factor of the kaon have been taken atdifferent values of the invariant center of mass energy w in the range w=1.8, 1.85, 1.98, 2.08 (gev), forone value of the transferred 4-momentum q2=2.35 (gev/c)2. in this analysis, we calculated σl and σt b...

Understanding the mechanism of vectorial proton pumping in biomolecules requires establishing the microscopic basis for the regulation of both thermodynamic and kinetic features of the relevant proton transfer steps. For the proton pump cytochrome c oxidase, while the regulation of thermodynamic driving force for key proton transfers has been discussed in great detail, the microscopic basis for...

We have performed a study of the isovector, octet and singlet axial charges proton in an extended chiral constituent quark model, where all possible $uudq\bar{q}$~($q=u,d,s$) five-quark Fock components wave function are taken into account. The $^3P_0$ quark-antiquark creation mechanism is assumed to account for transition coupling between three- proton, corresponding strength fixed by fitting i...

In order to evaluate the utilization of variable ATP concentration produced by an oscillatory reaction (as in anaerobic glycolysis), we analyze the thermodynamic efficiency of power output of a cyclic, ATP-driven proton pump found in the plasma membrane of plant cells. The model used includes the coupling of potassium and calcium ion transport. Oscillations in the concentration of ATP can lead ...

Fine structure in proton emission from the 7/2−[523] ground state and from the 1/2[411] isomer in deformed nucleus Ho was studied by means of fusion-evaporation reactions and digital signal processing. Proton transitions to the first excited 2 state in Dy, with the branching ratio of Igs p (2 )=0.9±0.2% and Ip (2 )=1.7±0.5%, were observed. The data are analyzed within the non-adiabatic weak cou...

The coupling of proton chemistry with redox reactions is important in many enzymes and is central to energy transduction in biology. However, the mechanistic details are poorly understood. Here, we have studied tyrosine oxidation, a reaction in which the removal of one electron from the amino acid is linked to the release of its phenolic proton. Using the unique photochemical properties of phot...

We use a weak-coupling procedure and results of a shell-model calculation to compute the two-proton separation energy of 19Mg. Our result is at the upper end of the previous range, but 19Mg is still bound for single proton decay to 18Na. We also calculate the 2p decay width. Disciplines Physical Sciences and Mathematics | Physics Comments Suggested Citation: H.T. Fortune and R. Sherr. (2007). T...

Recent experimental determinations of the Nachtmann moments of the inelastic structure function of the proton F p 2 (x,Q 2), obtained at Jefferson Lab, are analyzed for values of the squared four-momentum transfer Q2 ranging from ≈ 0.1 to ≈ 2 (GeV/c)2. It is shown that such inelastic proton data exhibit a new type of scaling behavior and that the resulting scaling function can be interpreted as...