Atomic Beams

Contains a report on a research project.Lincoln Laboratory (Purchase Order DDL-B222)United States Department of the ArmyUnited States Department of the NavyUnited States Department of the Air Force (Contract AF19(122)-458

Molecular Beams

Contains reports on two research projects.Lincoln Laboratory, Purchase Order DDL B-00306U. S. ArmyU. S. NavyU. S. Air Force under Air Force Contract AF19(604)-520

HIV among people using anabolic steroids in the United Kingdom: an overview

Since the mid-1980s, preventing HIV transmission among people who inject drugs (PWIDs) has been one of the cornerstones of the UK’s response to HIV. The early comprehensive implementation of harm reduction, particularly needle and syringe programmes, has been widely acknowledged as key to a low prevalence of HIV among PWIDs in the UK. However, this harm-reduction strategy was developed to avert an HIV epidemic among people injecting heroin and while the prevalence in this population remains low, it is clear that there are now emerging populations of PWIDs with different patterns of drug use and risks

On the spectral properties of L_{+-} in three dimensions

This paper is part of the radial asymptotic stability analysis of the ground state soliton for either the cubic nonlinear Schrodinger or Klein-Gordon equations in three dimensions. We demonstrate by a rigorous method that the linearized scalar operators which arise in this setting, traditionally denoted by L_{+-}, satisfy the gap property, at least over the radial functions. This means that the interval (0,1] does not contain any eigenvalues of L_{+-} and that the threshold 1 is neither an eigenvalue nor a resonance. The gap property is required in order to prove scattering to the ground states for solutions starting on the center-stable manifold associated with these states. This paper therefore provides the final installment in the proof of this scattering property for the cubic Klein-Gordon and Schrodinger equations in the radial case, see the recent theory of Nakanishi and the third author, as well as the earlier work of the third author and Beceanu on NLS. The method developed here is quite general, and applicable to other spectral problems which arise in the theory of nonlinear equations

Molecular Beams

Contains a report on a research project

Atomic Beams

Contains reports on two research projects.Lincoln Laboratory, Purchase Order DDL-B158Department of the ArmyDepartment of the NavyDepartment of the Air Force under Contract AF 19(122)-45

Finite to infinite steady state solutions, bifurcations of an integro-differential equation

We consider a bistable integral equation which governs the stationary solutions of a convolution model of solid--solid phase transitions on a circle. We study the bifurcations of the set of the stationary solutions as the diffusion coefficient is varied to examine the transition from an infinite number of steady states to three for the continuum limit of the semi--discretised system. We show how the symmetry of the problem is responsible for the generation and stabilisation of equilibria and comment on the puzzling connection between continuity and stability that exists in this problem