On the EDM Cancellations in D-brane models

We analyze the possibility of simultaneous electron, neutron, and mercury electric dipole moment (EDM) cancellations in the mSUGRA and D--brane models. We find that the mercury EDM constraint practically rules out the cancellation scenario in D-brane models whereas in the context of mSUGRA it is still allowed with some fine-tuning.Comment: 10 pages, to appear in Phys. Rev. Let

Linking Conformation Change to Hemoglobin Activation Via Chain-Selective Time-resolved Resonance Raman Spectroscopy on Protoheme/Mesoheme Hybrids

Time-resolved Resonance Raman spectra are reported for Hb tetramers, in which the αand β chains are selectively substituted with mesoheme. The Soret absorption band shift in meso- relative to protoheme permits chain-selective excitation of heme RR spectra. The evolution of these spectra following HbCO photolysis show that geminate recombination rates and yields are the same for the two chains, consistent with recent results on 15N-heme isotopomer hybrids. The spectra also reveal systematic shifts in the deoxy-heme ν4 and νFe-His) RR bands, which are anti-correlated. These shifts are resolved for the successive intermediates in the protein structure, which have previously been determined from time-resolved UVRR spectra. Both chains show Fe-His bond compression in the immediate photoproduct, which relaxes during the formation of the first intermediate, Rdeoxy (0.07 μs), in which the proximal F-helix is proposed to move away from the heme. Subsequently, the Fe-His bond weakens, more so for the α than the β chains. The weakening is gradual for the β chains, but abrupt for the α chains, coinciding with completion of the R-T quaternary transition, at 20μs. Since the transition from fast- to slow-rebinding Hb also occurs at 20μs, the drop in the α chain νFe-His supports the localization of ligation restraint to tension in the Fe-His bond, at least in the α-chains. The mechanism is more complex in the β chains

Assessment of people’s knowledge and perceptions of vultures in some selected areas of Plateau state Nigeria and its conservation implications

The study was conducted to assess the perceptions, beliefs, knowledge and attitudes of people toward vultures. Four study sites from three local government areas in Jos were selected. Methods included the use of open ended, semi-structured questionnaires. Respondents were selected using stratified random sampling and purposive sampling. A hundred and sixty respondents participated in the study. Results revealed that the most seen and identified vulture species was the Hooded Vulture Necrosyrte monarchus 83(51.9%). Respondents’knowledge of what vultures eat and where they can be found showed varied knowledge among respondents. Respondents also thought that vultures had declined but could not link the decline to any human activity. Seventy-five (46.9%) of the respondents had negative perceptions of vultures, while 57(35.6%) had positive perceptions. Local beliefs about vultures revealed that vultures where perceived as evil by 38(23.7%) of the respondents. Knowledge of vulture importance in the environment was low, 77(48.1%) perceived vultures as not important while 72(45.0%) thought them important. Perception and knowledge about vultures was seen to affect the willingness of respondents to protect vultures. We conclude that knowledge and perceptions about Vultures is low, and might be related to the low sightings and interactions with the species due to the decline in vulture populations. We suggest that education and awareness programs and campaigns need to be intensified among the public to end Vulture persecution and decline Keywords: Perception, Attitude, Vulture, Biodiversity, Conservatio

Electron and Neutron Electric Dipole Moments in the Focus Point Scenario of SUGRA Model

We estimate the electron and neutron electric dipole moments in the focus point scenario of the minimal SUGRA model corresponding to large sfermion masses and moderate to large $\tan\beta$. There is a viable region of moderate fine-tuning in the parameter space, around $\tan\beta \simeq 5$, where the experimental limits on these electric dipole moments can be satisfied without assuming unnaturally small phase angles. But the fine-tuning constraints become more severe for $\tan\beta > 10$.Comment: 16 pages, LaTeX, 4 postscript figures. Very minor changes made in only a few sentences for clarification. Final version to appear in Phys. Rev.

Relaxation of the Dynamical Gluino Phase and Unambiguous Electric Dipole Moments

We propose a new axionic solution of the strong CP problem with a Peccei-Quinn mechanism using the gluino rather than quarks. The spontaneous breaking of this new global U(1) at 10^{11} GeV also generates the supersymmetry breaking scale of 1 TeV (solving the so-called \mu problem at the same time) and results in the MSSM (Minimal Supersymmetric Standard Model) with R parity conservation. In this framework, electric dipole moments become calculable without ambiguity.Comment: Typos corrected and a footnote added, 10 p

Snake orbits and related magnetic edge states

We study the electron motion near magnetic field steps at which the strength and/or sign of the magnetic field changes. The energy spectrum for such systems is found and the electron states (bound and scattered) are compared with their corresponding classical paths. Several classical properties as the velocity parallel to the edge, the oscillation frequency perpendicular to the edge and the extent of the states are compared with their quantum mechanical counterpart. A class of magnetic edge states is found which do not have a classical counterpart.Comment: 8 pages, 10 figure

Surface Electronic Structures and Field Emission Currents at Sodium Overlayers on Low-Index Tungsten Surfaces

The total energy distributions (TEDs) of the emission currents in field emission and surface photofield emission and the overlayer-induced modifications in the surface electronic structures from the technologically important W surfaces with the commensurate W(100)/Na c(2x2), W(110)/Na (2x2) and W(111)/Na (1x1) overlayers are calculated. The TEDs obtained by our recent numerical method that extends the full-potential linear augmented plane wave method for the electronic structures to the study of field and photofield emission are used to interpret the shifts of the peaks in the experimental TEDs in field emission and photofield emission from the W(100) and W(110) surfaces at sub-monolayer and monolayer Na coverage. Hybridization of the 3s Na states with the pairs of dz2-like surface states of the strong Swanson hump in clean W(100) and surface resonances in clean W(111) below the Fermi energy shifts these W states by about -1.2 eV and -1.0 eV, thus stabilizing these states, to yield new strong peaks in the TEDs in field emission and photofield emission from W(100)/Na c(2x2) and W(111)/Na (1x1) respectively. The effect of Na intralayer interactions are discussed and are shown to shift the strong s- and p-like peaks in the surface density of states of W(110) below and above the Fermi energy respectively to lower energy with increased Na coverage, in agreement with experiments.Comment: 12 page

Surface States and Resonances in Field Emission from Low Index Facets of Clean Tungsten

The energies, widths, and shapes of features observed in the total energy distributions in field emission from W(100) and W(111) are compared with the results of a full-potential LAPW calculation of the surface density of states based on a supercell model of the crystal structure at the metal-vacuum interface. The Swanson hump on W(100) is attributed to two bands of surface states and surface resonances of dz^2 symmetry that are highly localised at the center of the surface Brillouin zone (Gamma_bar), and a second peak observed at lower energy is attributed to a band of surface resonances, also of dz^2 symmetry, centred at 0.11 A^(-1) along Gamma_bar to X_bar. The energy scale of the calculated total energy distribution is compressed by about 20% relative to the experimental data. The present calculation yields strong evidence that the broad asymmetric peak observed on W(111) is due to emission from a band of surface resonances. Further calculations for W(111) are proposed both to test the accuracy of the band model and to take into account the velocity factor that enters in a calculation of the emission current.Comment: 18 text pages, 8 figure pages, to be published in 'Progress in Surface Science

Mixing of the CP Even and the CP Odd Higgs Bosons and the EDM Constraints

The mixing among the CP even and the CP odd neutral Higgs bosons of MSSM by one loop induced effects in the presence of CP phases is investigated using three different mechanisms to satisfy the EDM constraints, i.e., a fine tuning of phases, a heavy sparticle spectrum, and the cancellation mechanism. It is shown that if a mixing effect among the CP even and the CP odd Higgs bosons is observed experimentally, then it is only the cancellation mechanism that can survive under the naturalness constraint.Comment: 14 pages, Latex and 4figures. A new paragraph is added and few more references. One figure is modified. To appear in Phys. Rev.