Persistence of inflationary shocks: Implications for West African Monetary Union Membership

Plans are far advanced to form a second monetary union, the West African Monetary Zone (WAMZ), in Africa. While much attention is being placed on convergence criteria and preparedness of the five aspiring member states, less attention is being placed on the extent to which the dynamics of inflation in individual countries are (dis)similar. This paper aims to stimulate debate on the long term sustainability of the union by examining the dynamics of inflation within these countries. Using Fractional Integration (FI) methods, we establish that some significant differences exist among the countries. Shocks to inflation in Sierra Leone are non mean reverting; results for The Gambia, Ghana and Guinea-Bissau suggest some inflation persistence, despite being mean reverting. Some policy implications are discussed and some warnings are raised

mTORtuous effect on the elastic heart

Both during normal physiological development as well as in the face of cardiac stress, the heart exhibits enormous plasticity in growth, remodeling, and atrophy. Central to this adaptive ability is the heart’s metabolic capacity to react quickly both anabolically and catabolically in order to maintain cardiac output. In response to hemodynamic stress, the heart adapts to maintain overall contractile function via pathological remodeling that often includes cardiomyocyte hypertrophy as well as changes in cardiomyocyte metabolism that eventually lead to contractile dysfunction and heart failure. It is unclear as to whether the metabolic changes that accompany pathological hypertrophy are adaptive or maladaptive; however, as in most complex biological systems, the answer likely resides somewhere in the middle. Goodwin et al. demonstrated in 1998 that hemodynamic stress increases carbohydrate use for ATP generation and induces cardiac remodeling. Numerous subsequent studies have attributed the change in metabolism and cardiac remodeling to activation of the mammalian (or mechanistic) target of rapamycin (mTOR), a kinase that is a primary regulator of myocardial protein synthesis. Recent experimental models that manipulate cardiac metabolism and mTOR signaling have provided new insights into the relationship between metabolic and structural remodeling (reviewed in detail by Kundu et al.). One hopes that such models will identify metabolic changes that precede remodeling in order to find therapeutic targets for cardiac disease

Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition in the film from a tetragonal to cubic symmetry. At low thickness, the in-plane tensile stress induces a tetragonal distortion of the lattice that generates a perpendicular anisotropy, large enough to overcome the shape anisotropy and to stabilize the magnetization easy axis out of plane. However, in thicker films, the lattice relaxation toward the cubic structure of the bulk allows the shape anisotropy to force the magnetization to be in plane aligned

Variational Study of the Phase Transition at Finite T in the λϕ4\lambda \phi^4 -Theory

Assuming triviality of the 4-dimensional $\lambda \phi ^4$-theory we compute the effective potential by means of a self consistent Feynman-Bogoliubov method. This potential $U_{eff}^{FB}$ depends on a UV-cutoff, which is fixed by a stability condition for the gap-equation for the plasma mass. It shows a second order phase transition at zero temperature, in agreement with a large amount of analytical and RG analysis as well as Monte Carlo numerical evidence. As the cutoff $\Lambda$ is removed the renormalized self coupling constant $\lambda _R$ goes to zero consistent with the claim of triviality. At finite temperature the phase transition becomes weakly first order.Comment: 8 pages, latex, 4 figures available from author e-mail: [email protected], submitted to Phys. Lett.

Cut Vertices and Semi-Inclusive Deep Inelastic Processes

Cut vertices, a generalization of matrix elements of local operators, are revisited, and an expansion in terms of minimally subtracted cut vertices is formulated. An extension of the formalism to deal with semi-inclusive deep inelastic processes in the target fragmentation region is explicitly constructed. The problem of factorization is discussed in detail.Comment: LaTex2e, 24 pages including 17 postscript figure

Chiral Unitary Approach To The N*N*pi, N*N*eta Couplings For The N*(1535) Resonance

Using a chiral unitary model in which the negative parity nucleon resonance $N^\ast \equiv N^\ast(1535)$ is generated dynamically by means of the Bethe Salpeter equation with coupled meson baryon channels in the $S = 0$ sector, we have obtained the $\pi^0 N^\ast N^\ast$ and $\eta N^\ast N^\ast$ couplings. The $\pi^0 N^\ast N^\ast$ coupling has smaller strength and the same sign as the $\pi^0 N N$ coupling. This rules out the mirror assignment of chiral symmetry where the ground state nucleon $N$ and the negative parity resonance $N^\ast$ are envisaged as chiral partners in the baryon sector.Comment: 30 pages, 15 figures (ps files). The new version discusses pi-N scattering around the N*(1535) resonanc

Vanishing magnetic mass in QED3_{3} with a Chern-Simons term

We show that, at one loop, the magnetic mass vanishes at finite temperature in QED in any dimension. In QED$_{3}$, even the zero temperature part can be regularized to zero. We calculate the two loop contributions to the magnetic mass in QED$_{3}$ with a Chern-Simons term and show that it vanishes. We give a simple proof which shows that the magnetic mass vanishes to all orders at finite temperature in this theory. This proof also holds for QED in any dimension.Comment: revtex, 7 pages, 5 figure

Yang-Mills Interactions and Gravity in Terms of Clifford Algebra

A model of Yang-Mills interactions and gravity in terms of the Clifford algebra Cl(0,6) is presented. The gravity and Yang-Mills actions are formulated as different order terms in a generalized action. The feebleness of gravity as well as the smallness of the cosmological constant and theta terms are discussed at the classical level. The invariance groups, including the de Sitter and the Pati-Salam SU(4) subgroups, consist of gauge transformations from either side of an algebraic spinor. Upon symmetry breaking via the Higgs fields, the remaining symmetries are the Lorentz SO(1,3), color SU(3), electromagnetic U(1)_EM, and an additional U(1). The first generation leptons and quarks are identified with even and odd parts of spinor idempotent projections. There are still several shortcomings with the current model. Further research is needed to fully recover the standard model results.Comment: 20 pages, to appear in Advances in Applied Clifford Algebra

Charge Dynamics in Cuprate Superconductors

In this lecture we present some interesting issues that arise when the dynamics of the charge carriers in the CuO$_2$ planes of the high temperature superconductors is considered. Based on the qualitative picture of doping, set by experiments and some previous calculations, we consider the strength of various inter and intra-cell charge transfer susceptibilities, the question of Coulomb screening and charge collective modes. The starting point is the usual p-d model extended by the long range Coulomb (LRC) interaction. Within this model it is possible to examine the case in which the LRC forces frustrate the electronic phase separation, the instability which is present in the model without an LRC interaction. While the static dielectric function in such systems is negative down to arbitrarily small wavevectors, the system is not unstable. We consider the dominant electronic charge susceptibilities and possible consequences for the lattice properties.Comment: 14 pages, 15 figures, latex, to be published in "From Quantum Mechanics to Technology", Lecture Notes in Physics, Springe

Modeling the transition from decompensated to pathological hypertrophy

Background--Long-chain acyl-CoA synthetases (ACSL) catalyze the conversion of long-chain fatty acids to fatty acyl-CoAs. Cardiac-specific ACSL1 temporal knockout at 2 months results in a shift from FA oxidation toward glycolysis that promotes mTORC1-mediated ventricular hypertrophy. We used unbiased metabolomics and gene expression analyses to examine the early effects of genetic inactivation of fatty acid oxidation on cardiac metabolism, hypertrophy development, and function. Methods and Results--Global cardiac transcriptional analysis revealed differential expression of genes involved in cardiac metabolism, fibrosis, and hypertrophy development in Acsl1 H-/- hearts 2 weeks after Acsl1 ablation. Comparison of the 2- and 10-week transcriptional responses uncovered 137 genes whose expression was uniquely changed upon knockdown of cardiac ACSL1, including the distinct upregulation of fibrosis genes, a phenomenon not observed after complete ACSL1 knockout. Metabolomic analysis identified metabolites altered in hearts displaying partially reduced ACSL activity, and rapamycin treatment normalized the cardiac metabolomic fingerprint. Conclusions--Short-term cardiac-specific ACSL1 inactivation resulted in metabolic and transcriptional derangements distinct from those observed upon complete ACSL1 knockout, suggesting heart-specific mTOR (mechanistic target of rapamycin) signaling that occurs during the early stages of substrate switching. The hypertrophy observed with partial Acsl1 ablation occurs in the context of normal cardiac function and is reminiscent of a physiological process, making this a useful model to study the transition from physiological to pathological hypertrophy