Molecules in external fields: a semiclassical analysis

We undertake a semiclassical analysis of the spectral properties (modulations of photoabsorption spectra, energy level statistics) of a simple Rydberg molecule in static fields within the framework of Closed-Orbit/Periodic-Orbit theories. We conclude that in addition to the usual classically allowed orbits one must consider classically forbidden diffractive paths. Further, the molecule brings in a new type of 'inelastic' diffractive trajectory, different from the usual 'elastic' diffractive orbits encountered in previous studies of atomic and analogous systems such as billiards with point-scatterers. The relative importance of inelastic versus elastic diffraction is quantified by merging the usual Closed Orbit theory framework with molecular quantum defect theory.Comment: 4 pages, 3 figure

Symmetry breaking in crossed magnetic and electric fields

We present the first observations of cylindrical symmetry breaking in highly excited diamagnetic hydrogen with a small crossed electric field, and we give a semiclassical interpretation of this effect. As the small perpendicular electric field is added, the recurrence strengths of closed orbits decrease smoothly to a minimum, and revive again. This phenomenon, caused by interference among the electron waves that return to the nucleus, can be computed from the azimuthal dependence of the classical closed orbits.Comment: 4 page REVTeX file including 5 postscript files (using psfig) Accepted for publication in Physical Review Letters. Difference from earlier preprint: we have discovered the cause of the earlier apparent discrepancy between experiment and theory and now achieve excellent agreemen

Growth and texture of Spark Plasma Sintered Al2O3 ceramics: a combined analysis of X-rays and Electron Back Scatter Diffraction

Textured alumina ceramics were obtained by Spark Plasma Sintering (SPS) of undoped commercial a-Al2O3 powders. Various parameters (density, grain growth, grain size distribution) of the alumina ceramics, sintered at two typical temperatures 1400{\deg}C and 1700{\deg}C, are investigated. Quantitative textural and structural analysis, carried out using a combination of Electron Back Scattering Diffraction (EBSD) and X-ray diffraction (XRD), are represented in the form of mapping, and pole figures. The mechanical properties of these textured alumina ceramics include high elastic modulus and hardness value with high anisotropic nature, opening the door for a large range of applicationsComment: 16 pages, 6 figures, submitted to J. Appl. Phy

CRISPR/Cas9 DNA cleavage at SNP-derived PAM enables both in vitro and in vivo KRT12 mutation-specific targeting

CRISPR/Cas9-based therapeutics hold the possibility for permanent treatment of genetic disease. The potency and specificity of this system has been used to target dominantly inherited conditions caused by heterozygous missense mutations through inclusion of the mutated base in the short-guide RNA (sgRNA) sequence. This research evaluates a novel approach for targeting heterozygous single-nucleotide polymorphisms (SNPs) using CRISPR/Cas9. We determined that a mutation within KRT12, which causes Meesmann's epithelial corneal dystrophy (MECD), leads to the occurrence of a novel protospacer adjacent motif (PAM). We designed an sgRNA complementary to the sequence adjacent to this SNP-derived PAM and evaluated its potency and allele specificity both in vitro and in vivo. This sgRNA was found to be highly effective at reducing the expression of mutant KRT12 mRNA and protein in vitro. To assess its activity in vivo we injected a combined Cas9/sgRNA expression construct into the corneal stroma of a humanized MECD mouse model. Sequence analysis of corneal genomic DNA revealed non-homologous end-joining repair resulting in frame-shifting deletions within the mutant KRT12 allele. This study is the first to demonstrate in vivo gene editing of a heterozygous disease-causing SNP that results in a novel PAM, further highlighting the potential for CRISPR/Cas9-based therapeutics

Semiclassical quantization of the hydrogen atom in crossed electric and magnetic fields

The S-matrix theory formulation of closed-orbit theory recently proposed by Granger and Greene is extended to atoms in crossed electric and magnetic fields. We then present a semiclassical quantization of the hydrogen atom in crossed fields, which succeeds in resolving individual lines in the spectrum, but is restricted to the strongest lines of each n-manifold. By means of a detailed semiclassical analysis of the quantum spectrum, we demonstrate that it is the abundance of bifurcations of closed orbits that precludes the resolution of finer details. They necessitate the inclusion of uniform semiclassical approximations into the quantization process. Uniform approximations for the generic types of closed-orbit bifurcation are derived, and a general method for including them in a high-resolution semiclassical quantization is devised

The Death Penalty: Should the Judge or the Jury Decide Who Dies?

This article addresses the effect of judge versus jury decision making through analysis of a database of all capital sentencing phase hearing trials in the State of Delaware from 1977– 2007. Over the three decades of the study, Delaware shifted responsibility for death penalty sentencing from the jury to the judge. Currently, Delaware is one of the handful of states that gives the judge the final decision-making authority in capital trials. Controlling for a number of legally relevant and other predictor variables, we find that the shift to judge sentencing significantly increased the number of death sentences. Statutory aggravating factors, stranger homicides, and the victim’s gender also increased the likelihood of a death sentence, as did the county of the homicide. We reflect on the implications of these results for debates about the constitutionality of judge sentencing in capital cases

Victim Gender and the Death Penalty

Previous research suggests that cases involving female victims are more likely to result in death sentences. The current study examines possible reasons for this relationship using capital punishment data from the state of Delaware. Death was sought much more for murders of either male or female white victims compared to murders of black male victims. Analyzing capital sentencing hearings in Delaware from 1977-2007 decided by judges or juries, we found that both characteristics of the victims and characteristics of the murders differentiated male and female victim cases. The presence of sexual victimization, the method of killing, the relationship between the victim and the defendant, and whether or not the victim had family responsibilities all predicted the likelihood of a death sentence and help to explain why cases with female victims are more likely to be punished with a death sentence

The Death Penalty: Should the Judge or the Jury Decide Who Dies?

This article addresses the effect of judge versus jury decision making through analysis of a database of all capital sentencing phase hearing trials in the State of Delaware from 1977– 2007. Over the three decades of the study, Delaware shifted responsibility for death penalty sentencing from the jury to the judge. Currently, Delaware is one of the handful of states that gives the judge the final decision-making authority in capital trials. Controlling for a number of legally relevant and other predictor variables, we find that the shift to judge sentencing significantly increased the number of death sentences. Statutory aggravating factors, stranger homicides, and the victim’s gender also increased the likelihood of a death sentence, as did the county of the homicide. We reflect on the implications of these results for debates about the constitutionality of judge sentencing in capital cases

Microscopic Calculation of Total Ordinary Muon Capture Rates for Medium - Weight and Heavy Nuclei

Total Ordinary Muon Capture (OMC) rates are calculated on the basis of the Quasiparticle Random Phase Approximation for several spherical nuclei from 90^Zr to 208^Pb. It is shown that total OMC rates calculated with the free value of the axial-vector coupling constant g_A agree well with the experimental data for medium-size nuclei and exceed considerably the experimental rates for heavy nuclei. The sensitivity of theoretical OMC rates to the nuclear residual interactions is discussed.Comment: 27 pages and 3 figure