Eleven-Dimensional Supergravity in Light-Cone Superspace

We show that Supergravity in eleven dimensions can be described in terms of a constrained superfield on the light-cone, without the use of auxiliary fields. We build its action to first order in the gravitational coupling constant \kappa, by "oxidizing" (N=8,d=4) Supergravity. This is simply achieved, as for N=4 Yang-Mills, by extending the transverse derivatives into superspace. The eleven-dimensional SuperPoincare algebra is constructed and a fourth order interaction is conjectured.Comment: 18 page

Maximal supersymmetry and exceptional groups

The article is a tribute to my old mentor, collaborator and friend Murray Gell-Mann. In it I describe work by Pierre Ramond, Sung-Soo Kim and myself where we describe the N = 8 Supergravity in the light-cone formalism. We show how the Cremmer-Julia E7(7) non-linear symmetry is implemented and how the full supermultiplet is a representation of the E7(7) symmetry. I also show how the E7(7) symmetry is a key to understand the higher order couplings in the theory and is very useful when we discuss possible counterterms for this theory.Comment: Proceedings of Conference in Honour of Murray Gell-Mann's 80th Birthda

LC_2 formulation of supergravity

We formulate (N=1, d=11) supergravity in components in light-cone gauge (LC_2) to order $\kappa$. In this formulation, we use judicious gauge choices and the associated constraint relations to express the metric, three-form and gravitino entirely in terms of the physical degrees of freedom in the theory.Comment: 11 page

Gauge-invariant correlation functions in light-cone superspace

We initiate a study of correlation functions of gauge-invariant operators in N=4 super Yang-Mills theory using the light-cone superspace formalism. Our primary aim is to develop efficient methods to compute perturbative corrections to correlation functions. This analysis also allows us to examine potential subtleties which may arise when calculating off-shell quantities in light-cone gauge. We comment on the intriguing possibility that the manifest N=4 supersymmetry in this approach may allow for a compact description of entire multiplets and their correlation functions.Comment: 35 pages, several figure

Uteroplacental bleeding disorders during pregnancy: do missing paternal characteristics influence risk?

BACKGROUND: Several studies have assessed the risks of uteroplacental bleeding disorders in relation to maternal characteristics. The association between uteroplacental bleeding disorders and paternal characteristics, however, has received considerably less attention. Data on paternal demographics, notably race and age, from birth certificate data are becoming increasingly incomplete in recent years. This pattern of increasingly underreporting of paternal demographic data led us to speculate that pregnancies for which paternal characteristics are partially or completely missing may be associated with increased risk for uteroplacental bleeding disorders. The objective of this study is to examine the association between placenta previa and placental abruption and missing paternal age and race. METHODS: A retrospective cohort study using U.S. linked birth/infant death data from 1995 through 2001 (n = 26,336,549) was performed. Risks of placenta previa and placental abruption among: (i) pregnancies with complete paternal age and race data; (ii) paternal age only missing; (iii) paternal race only missing; and (iv) both paternal age and race missing, were evaluated. Relative risk (RR) with 95% confidence interval (CI) for placenta previa and placental abruption by missing paternal characteristics were derived after adjusting for confounders. RESULTS: Adjusted RR for placental abruption were 1.30 (95% CI 1.24, 1.37), 1.00 (95% CI 0.95, 1.05), and 1.08 (95% CI 1.06, 1.10) among pregnancies with "paternal age only", "paternal race only", and "both paternal age and race" missing, respectively. The increased risk of placental abruption among the "paternal age only missing" category is partly explained by increased risks among whites aged 20–29 years, and among blacks aged ≥30 years. However, no clear patterns in the associations between missing paternal characteristics and placenta previa were evident. CONCLUSION: Missing paternal characteristics are associated with increased risk of placental abruption, likely mediated through low socio-economic conditions

MUCOADHESIVE POLYMERIC FILMS OF ACYCLOVIR PRONIOSOMES FOR BUCCAL ADMINISTRATION

Objective: The aim of the present work was to formulate and evaluate proniosomes of the poorly soluble drug, acyclovir incorporated in mucoadhesive polymeric films for improved buccal mucosal permeability of the drug while achieving prolonged release. Methods: Acyclovir was formulated as proniosomes using Span 60 and cholesterol. The prepared proniosomes were loaded into mucoadhesive polymeric films prepared with varying quantities of carbopol 934P and HPMC K15M. The proniosome incorporated films were evaluated for physicomechanical characters, mucoadhesion, swelling index, drug content, in vitro drug release and ex vivo permeation through porcine buccal mucosa. Results: Hydration of the proniosomes produced spherical vesicles or niosomes, which was confirmed by Scanning Electron Microscopy. The optimized formulation selected on the basis of vesicle size, entrapment efficiency PDI, Zetz potential and in vitro drug release was selected for incorporation into mucoadhesive polymeric films. All the films showed excellent physicomechanical characters. Formulations with higher proportions of carbopol produced slower in vitro drug release. The kinetics of release of drug from all the formulations appeared to be zero-order based on their regression coefficient values. Comparative evaluation of ex vivo permeation from niosomal and non-niosomal films indicated that the former demonstrated improved mucosal permeation and drug release was also sustained for the 8 h period. Conclusion: Mucoadhesive films impregnated with acyclovir loaded proniosomes could be a potential approach for buccal delivery of acyclovir for improving its absorption and bioavailability.&nbsp