Characterizing the role of the HspX protein from Mycobacterium tuberculosis as a subunit vaccine candidate in the small animal model of tuberculosis

2011 Fall.Includes bibliographical references.Tuberculosis (TB) is a bacterial disease of the lung, caused by Mycobacterium tuberculosis, and currently remains an important human pathogen. The only vaccine against tuberculosis licensed for human use is a live, attenuated strain of the closely related Mycobacterium bovis Bacille-Calmette Guerin (BCG), which offers little protection against pulmonary disease in adults, particularly against latent infection. Current vaccine strategies against TB include the development of subunit vaccines, which contain one to a few antigens. Subunit vaccines are delivered with an adjuvant formulation to mount an appropriate T cell response against the pathogen. One such antigen for vaccine design is the 16kDa small heat shock protein and molecular chaperone from Mtb, HspX. This protein has been implicated as a latency-associated antigen due its late expression and ability to re-stimulate T cells from latently infected patients. A previous study in our laboratory revealed that native HspX purified from Mtb was protective in mice against pulmonary TB when given as a vaccine. HspX expressed and purified from E coli in its recombinant form was not able to protect. We hypothesize that because HspX functions as a molecular chaperone, it requires its binding partners to remain biologically active as a vaccine. In this study, we test this hypothesis and we also tested the capacity of native HspX to protect guinea pigs experimentally infected with TB. Our results illustrate that, while native HspX protects in the mouse model, it does not confer protection in guinea pigs, suggesting differences in the establishment of Mtb physiologically in the lung

Operational multipartite entanglement classes for symmetric photonic qubit states

We present experimental schemes that allow to study the entanglement classes of all symmetric states in multiqubit photonic systems. In addition to comparing the presented schemes in efficiency, we will highlight the relation between the entanglement properties of symmetric Dicke states and a recently proposed entanglement scheme for atoms. In analogy to the latter, we obtain a one-to-one correspondence between well-defined sets of experimental parameters and multiqubit entanglement classes inside the symmetric subspace of the photonic system.Comment: 5 pages, 1 figur

The thermal state and interior structure of Mars

©2018. American Geophysical UnionThe present‐day thermal state, interior structure, composition, and rheology of Mars can be constrained by comparing the results of thermal history calculations with geophysical, petrological, and geological observations. Using the largest‐to‐date set of 3‐D thermal evolution models, we find that a limited set of models can satisfy all available constraints simultaneously. These models require a core radius strictly larger than 1,800 km, a crust with an average thickness between 48.8 and 87.1 km containing more than half of the planet's bulk abundance of heat producing elements, and a dry mantle rheology. A strong pressure dependence of the viscosity leads to the formation of prominent mantle plumes producing melt underneath Tharsis up to the present time. Heat flow and core size estimates derived from the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission will increase the set of constraining data and help to confine the range of admissible models.DFG, 280637173, FOR 2440: Materie im Inneren von Planeten - Hochdruck-, Planeten- und Plasmaphysi

Multiplying unitary random matrices - universality and spectral properties

In this paper we calculate, in the large N limit, the eigenvalue density of an infinite product of random unitary matrices, each of them generated by a random hermitian matrix. This is equivalent to solving unitary diffusion generated by a hamiltonian random in time. We find that the result is universal and depends only on the second moment of the generator of the stochastic evolution. We find indications of critical behavior (eigenvalue spacing scaling like $1/N^{3/4}$) close to $\theta=\pi$ for a specific critical evolution time $t_c$.Comment: 12 pages, 2 figure

Charged Particle with Magnetic Moment in the Aharonov-Bohm Potential

We considered a charged quantum mechanical particle with spin ${1\over 2}$ and gyromagnetic ratio $g\ne 2$ in the field af a magnetic string. Whereas the interaction of the charge with the string is the well kown Aharonov-Bohm effect and the contribution of magnetic moment associated with the spin in the case $g=2$ is known to yield an additional scattering and zero modes (one for each flux quantum), an anomaly of the magnetic moment (i.e. $g>2$) leads to bound states. We considered two methods for treating the case $g>2$. \\ The first is the method of self adjoint extension of the corresponding Hamilton operator. It yields one bound state as well as additional scattering. In the second we consider three exactly solvable models for finite flux tubes and take the limit of shrinking its radius to zero. For finite radius, there are $N+1$ bound states ($N$ is the number of flux quanta in the tube).\\ For $R\to 0$ the bound state energies tend to infinity so that this limit is not physical unless $g\to 2$ along with $R\to 0$. Thereby only for fluxes less than unity the results of the method of self adjoint extension are reproduced whereas for larger fluxes $N$ bound states exist and we conclude that this method is not applicable.\\ We discuss the physically interesting case of small but finite radius whereby the natural scale is given by the anomaly of the magnetic moment of the electron $a_e=(g-2)/2\approx 10^{-3}$.Comment: 16 pages, Latex, NTZ-93-0