Dissociative Autoionization in (1+2)-photon Above Threshold Excitation of H2 Molecules

We have theoretically studied the effect of dissociative autoionization on the photoelectron energy spectrum in (1+2)-photon above threshold ionization(ATI) of H2 molecules. We have considered excitation from the ground state X-singlet-Sigma-g+(v=0,j) to the doubly excited autoionizing states of singlet-Sigma-u+ and singlet-Pi-u+ symmetry, via the intermediate resonant B-singlet-Sigma-u+(v=5,j) states. We have shown that the photoelectron energy spectrum is oscillatory in nature and shows three distinct peaks above the photoelectron energy 0.7 eV. This feature has been observed in a recent experiment by Rottke et al, J. Phys. B, Vol. 30, p-4049 (1997).Comment: 11 pages and 4 figure

Stigma as a fundamental hindrance to the United States opioid overdose crisis response.

Alexander Tsai and co-authors discuss the role of stigma in responses to the US opioid crisis

BLACK HOLE MULTIPLETS AND SPONTANEOUS BREAKING OF LOCAL SUPERSYMMETRY

We classify states saturating a double or a single supersymmetric positivity bound of a four-dimensional N=4 supersymmetry. The massive four-dimensional double-bound states (Bogomolny states) are shown to form a light-like representation of ten-dimensional supersymmetry. The single-bound states form a massive representation (centrino multiplet) of a four-dimensional supersymmetry. The first component of the centrino multiplet is identified with extreme black holes with regular horizon which have one quarter of unbroken supersymmetry. The centrino multiplet includes a massive spin 3/2 state, the centrino, as a highest spin state. Existence of massive black hole supermultiplets may affect the massless sector of the theory. Assuming that gluino condensate is formed one can study its properties. The bilinear combination of covariantly constant Killing spinors supplies the possible form for a gluino condensate. The condensate has null properties, does not introduce a cosmological constant, and may lead to a spontaneous breaking of local supersymmetry. This suggests that centrino may provide a consistent super-Higgs mechanism.Comment: 15 pages, LaTe

Couplings of self-dual tensor multiplet in six dimensions

The (1,0) supersymmetry in six dimensions admits a tensor multiplet which contains a second-rank antisymmetric tensor field with a self-dual field strength and a dilaton. We describe the fully supersymmetric coupling of this multiplet to Yang-Mills multiplet, in the absence of supergravity. The self-duality equation for the tensor field involves a Chern-Simons modified field strength, the gauge fermions, and an arbitrary dimensionful parameter.Comment: 17 pages, latex, no figure

Genome-scale analysis identifies paralog lethality as a vulnerability of chromosome 1p loss in cancer.

Functional redundancy shared by paralog genes may afford protection against genetic perturbations, but it can also result in genetic vulnerabilities due to mutual interdependency1-5. Here, we surveyed genome-scale short hairpin RNA and CRISPR screening data on hundreds of cancer cell lines and identified MAGOH and MAGOHB, core members of the splicing-dependent exon junction complex, as top-ranked paralog dependencies6-8. MAGOHB is the top gene dependency in cells with hemizygous MAGOH deletion, a pervasive genetic event that frequently occurs due to chromosome 1p loss. Inhibition of MAGOHB in a MAGOH-deleted context compromises viability by globally perturbing alternative splicing and RNA surveillance. Dependency on IPO13, an importin-β receptor that mediates nuclear import of the MAGOH/B-Y14 heterodimer9, is highly correlated with dependency on both MAGOH and MAGOHB. Both MAGOHB and IPO13 represent dependencies in murine xenografts with hemizygous MAGOH deletion. Our results identify MAGOH and MAGOHB as reciprocal paralog dependencies across cancer types and suggest a rationale for targeting the MAGOHB-IPO13 axis in cancers with chromosome 1p deletion

Landau-Khalatnikov-Fradkin Transformations and the Fermion Propagator in Quantum Electrodynamics

We study the gauge covariance of the massive fermion propagator in three as well as four dimensional Quantum Electrodynamics (QED). Starting from its value at the lowest order in perturbation theory, we evaluate a non-perturbative expression for it by means of its Landau-Khalatnikov-Fradkin (LKF) transformation. We compare the perturbative expansion of our findings with the known one loop results and observe perfect agreement upto a gauge parameter independent term, a difference permitted by the structure of the LKF transformations.Comment: 9 pages, no figures, uses revte

Evaluating the impact of Mexico’s drug policy reforms on people who inject drugs in Tijuana, B.C., Mexico, and San Diego, CA, United States: a binational mixed methods research agenda

Background: Policymakers and researchers seek answers to how liberalized drug policies affect people who inject drugs (PWID). In response to concerns about the failing “war on drugs,” Mexico recently implemented drug policy reforms that partially decriminalized possession of small amounts of drugs for personal use while promoting drug treatment. Recognizing important epidemiologic, policy, and socioeconomic differences between the United States—where possession of any psychoactive drugs without a prescription remains illegal—and Mexico—where possession of small quantities for personal use was partially decriminalized, we sought to assess changes over time in knowledge, attitudes, behaviors, and infectious disease profiles among PWID in the adjacent border cities of San Diego, CA, USA, and Tijuana, Baja California, Mexico. Methods: Based on extensive binational experience and collaboration, from 2012–2014 we initiated two parallel, prospective, mixed methods studies: Proyecto El Cuete IV in Tijuana (n = 785) and the STAHR II Study in San Diego (n = 575). Methods for sampling, recruitment, and data collection were designed to be compatible in both studies. All participants completed quantitative behavioral and geographic assessments and serological testing (HIV in both studies; hepatitis C virus and tuberculosis in STAHR II) at baseline and four semi-annual follow-up visits. Between follow-up assessment visits, subsets of participants completed qualitative interviews to explore contextual factors relating to study aims and other emergent phenomena. Planned analyses include descriptive and inferential statistics for quantitative data, content analysis and other mixed-methods approaches for qualitative data, and phylogenetic analysis of HIV-positive samples to understand cross-border transmission dynamics. Results: Investigators and research staff shared preliminary findings across studies to provide feedback on instruments and insights regarding local phenomena. As a result, recruitment and data collection procedures have been implemented successfully, demonstrating the importance of binational collaboration in evaluating the impact of structural-level drug policy reforms on the behaviors, health, and wellbeing of PWID across an international border. Conclusions: Our prospective, mixed methods approach allows each study to be responsive to emerging phenomena within local contexts while regular collaboration promotes sharing insights across studies. The strengths and limitations of this approach may serve as a guide for other evaluations of harm reduction policies internationally

From Words to Action: Comparing the Disparities Between National Drug Policy and Local Implementation in Tijuana, Mexico and Vancouver, Canada

D. M. Smith - Division of Global Public Health, Department of Medicine, University of California, San Diego, USA; Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, CanadaD. Werb - Division of Global Public Health, Department of Medicine, University of California, San Diego, USA; International Centre for Science in Drug Policy, St. Michael’s Hospital, Toronto, CanadaS.A. Strathdee - Division of Global Public Health, Department of Medicine, University of California, San Diego, US

Epigenetics as a mechanism driving polygenic clinical drug resistance

Aberrant methylation of CpG islands located at or near gene promoters is associated with inactivation of gene expression during tumour development. It is increasingly recognised that such epimutations may occur at a much higher frequency than gene mutation and therefore have a greater impact on selection of subpopulations of cells during tumour progression or acquisition of resistance to anticancer drugs. Although laboratory-based models of acquired resistance to anticancer agents tend to focus on specific genes or biochemical pathways, such 'one gene : one outcome' models may be an oversimplification of acquired resistance to treatment of cancer patients. Instead, clinical drug resistance may be due to changes in expression of a large number of genes that have a cumulative impact on chemosensitivity. Aberrant CpG island methylation of multiple genes occurring in a nonrandom manner during tumour development and during the acquisition of drug resistance provides a mechanism whereby expression of multiple genes could be affected simultaneously resulting in polygenic clinical drug resistance. If simultaneous epigenetic regulation of multiple genes is indeed a major driving force behind acquired resistance of patients' tumour to anticancer agents, this has important implications for biomarker studies of clinical outcome following chemotherapy and for clinical approaches designed to circumvent or modulate drug resistance