Cell-based gene therapy for mending infarcted hearts

The goal of this study was to analyse the efficiency of a combinatorial cell/growth factor therapy to improve function of infarcted murine hearts. The Insulin-like Growth Factor-1 (IGF-1) isoform, IGF-1Ea, has been shown to reduce scar formation and decrease cell death after MI. The present study utilized P19Cl6-derived, IGF-1Ea over-expressing cardiomyocytes to achieve its goal. The P19Cl6 cells were stably transduced with IGF-1Ea using a lentiviral vector and investigated first in vitro for their feasibility for in vivo cell therapy. The engineered pluripotent cells over-expressing IGF-1Ea survived better to hypoxia-induced injury than the control cells. The cells maintained their pluripotency and efficient differentiation capacity towards ventricular cardiomyocyte lineage, generating large quantities of cardiomyocytes optimal for the transplantation study. The generated cardiomyocytes were functionally active and exhibited a mature phenotype. Transplantation of the cardiomyocytes into allogeneic wild type murine infarcted hearts conferred a tendency for maintenance of function at short-term time point. At long-term however, this effect was lost, returning to the level of the control infarcted hearts. Cell tracing assessment revealed engraftment of both IGF-1Ea- and empty-cells, although the cells failed to couple with the recipient tissue. Scar size and capillary density analyses revealed no significant difference between the cells transplanted compared to the saline treated hearts, corroborating with the long-term functional data. Interestingly, the IGF- 1Ea-cell transplanted hearts expressed significantly higher amount of VEGFa compared to the controls, albeit no change in capillary density. Further investigation revealed that the enhanced VEGFa expression in IGF-1Ea-cells transplanted hearts was associated with reduced hypertrophy, marked by reduced cell cross-sectional area at the border-zone, aSK and bMHC expression compared to the control hearts. Nonetheless, modulation of hypertrophic response and transplantation of IGF-1Ea-cells were not able to confer lasting functional preservation, possibly due to lack of sufficient engraftment and coupling of the transplanted cells

Link homology and equivariant gauge theory

The singular instanton Floer homology was defined by Kronheimer and Mrowka in connection with their proof that the Khovanov homology is an unknot detector. We study this theory for knots and two-component links using equivariant gauge theory on their double branched covers. We show that the special generator in the singular instanton Floer homology of a knot is graded by the knot signature mod 4, thereby providing a purely topological way of fixing the absolute grading in the theory. Our approach also results in explicit computations of the generators and gradings of the singular instanton Floer chain complex for several classes of knots with simple double branched covers, such as two-bridge knots, torus knots, and Montesinos knots, as well as for several families of two-components links.Comment: 59 pages. Corrected a grading error in Lemma 2.5, which affected calculations for some of the knot

Effective potential and geodesic motion in Kerr-de Sitter space-time

In the present work, geodesic trajectories in Kerr-de Sitter geometry is analyzed. From the mathematical solution of Lagrangian formalism appropriate to motions in the equatorial plane (for which 'theta' = 0 and 'theta' = (constant)= pi/2) can give potential energy of massive and massless particles for rotating axisymetric black hole. From this, for a particular value of cosmological constant, Kerr parameter, mass, angular momentum and impact parameter; variation of potential with distance can be found. Similarly, for a particular value of cosmological constant, mass and Kerr parameter; variation of velocity with distance can be found

Effect of Ohmic environment on optimally controlled flux-biased phase qubit

We analyze the effect of environment on the gate operation of flux-biased phase qubits. We employ the master equation for a reduced density matrix of the qubit system coupled to an Ohmic environment, described by the Caldeira-Leggett model. Numerically solving this equation, we evaluate the gate error as a function of energy splitting between qubit states, junction capacitance, and temperature. The analysis is presented for single-quadrature microwave (control) pulses as well as for two-quadrature pulses, which lower the gate error significantly for idealized systems in the absence of environment. Our results indicate that two-quadrature pulses outperform single quadrature pulses even in the presence of environment.Comment: 5 pages and 4 figure

Majorana Flat Bands in s-Wave Gapless Topological Superconductors

We demonstrate how the non-trivial interplay between spin-orbit coupling and nodeless $s$-wave superconductivity can drive a fully gapped two-band topological insulator into a time-reversal invariant gapless topological superconductor supporting symmetry-protected Majorana flat bands. We characterize topological phase diagrams by a ${\mathbb Z}_2 \times{\mathbb Z}_2$ partial Berry-phase invariant, and show that, despite the trivial crystal geometry, no unique bulk-boundary correspondence exists. We trace this behavior to the anisotropic quasiparticle bulk gap closing, linear vs. quadratic, and argue that this provides a unifying principle for gapless topological superconductivity. Experimental implications for tunneling conductance measurements are addressed, relevant for lead chalcogenide materials.Comment: 5 pages, 4 figures, Phys. Rev. B, Rapid Comm. published versio

The Southeast U.S.A. Shrimp Industry: Issues Related to Trade and Antidumping Duties

On December 31, 2003 a coalition representing Southeast U.S.A. shrimp harvesters and processors filed a petition with the U.S. International Trade Administration and the U.S. International Trade Commission seeking relief in the form of antidumping duties from what the coalition perceived as unfair trade practices by six countries—China, Vietnam, India, Thailand, Ecuador, and Brazil. After an exhaustive investigation, an affirmative finding of dumping and injury was found, and duties were imposed on subject merchandise from these six countries. This study examines the factors that led to the petition being filed, the investigation process, and the outcome associated with the imposition of antidumping duties. Overall, the study concludes that while the duties resulted in a limited amount of trade deflection, particularly among those countries assessed with higher duties, much of the protective effect that might have been forthcoming from restricting imports from the six named countries was eroded by trade diversion to countries not included in the petition.Antidumping duties, shrimp, trade, United States of America, Environmental Economics and Policy, International Relations/Trade, F13, Q17,

Youth Political Engagement and Democratic Culture in Republican Nepal

Nepal’s transformation from an autocratic monarchy to a democratic republic presupposes the development of democratic institutions, and the current generation of Nepali youth, particularly those in higher education, are uniquely situated in that process. As such Nepali youth constitute a distinct generation along the lines specified by Karl Mannheim and others. In the past efforts to mobilize Nepalese youth have been aimed at integrating them as useful assets in the service of Nepalese political institutions, such as political student unions, but in this paper, based on fieldwork and interview data collected in 2013 and 2016, we argue that politically active youth today should be understood as an autonomous though heterogeneous constituent force that is in counterpoint with normative political institutions