Implementing antiretroviral therapy in rural communities: the Lusikisiki model of decentralized HIV/AIDS care.

Health worker shortages are a major bottleneck to scaling up antiretroviral therapy (ART), particularly in rural areas. In Lusikisiki, a rural area of South Africa with a population of 150,000 serviced by 1 hospital and 12 clinics, Médecins Sans Frontières has been supporting a program to deliver human immunodeficiency virus (HIV) services through decentralization to primary health care clinics, task shifting (including nurse-initiated as opposed to physician-initiated treatment), and community support. This approach has allowed for a rapid scale-up of treatment with satisfactory outcomes. Although the general approach in South Africa is to provide ART through hospitals-which seriously limits access for many people, if not the majority of people-1-year outcomes in Lusikisiki are comparable in the clinics and hospital. The greater proximity and acceptability of services at the clinic level has led to a faster enrollment of people into treatment and better retention of patients in treatment (2% vs. 19% lost to follow-up). In all, 2200 people were receiving ART in Lusikisiki in 2006, which represents 95% coverage. Maintaining quality and coverage will require increased resource input from the public sector and full acceptance of creative approaches to implementation, including task shifting and community involvement

Nonperturbative renomalization group for Einstein gravity with matter

we investigate the exact renormalization group (RG) in Einstein gravity coupled to N-component scalar field, working in the effective average action formalism and background field method. The truncated evolution equation is obtained for the Newtonian and cosmological constants. We have shown that screening or antiscreening behaviour of the gravitational coupling depends cricially on the choice of scalar-gravitational $\xi$ and the number of scalar fields.Comment: 7 pages, LaTeX, a few typos correcte

Die neuen Lautzeichen im Tocharischen

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Signatures of nonadiabatic O2 dissociation at Al(111): First-principles fewest-switches study

Recently, spin selection rules have been invoked to explain the discrepancy between measured and calculated adsorption probabilities of molecular oxygen reacting with Al(111). In this work, we inspect the impact of nonadiabatic spin transitions on the dynamics of this system from first principles. For this purpose the motion on two distinct potential-energy surfaces associated to different spin configurations and possible transitions between them are inspected by means of the Fewest Switches algorithm. Within this framework we especially focus on the influence of such spin transitions on observables accessible to molecular beam experiments. On this basis we suggest experimental setups that can validate the occurrence of such transitions and discuss their feasibility.Comment: 13 pages, 7 figure

Spacetime Structure of an Evaporating Black Hole in Quantum Gravity

The impact of the leading quantum gravity effects on the dynamics of the Hawking evaporation process of a black hole is investigated. Its spacetime structure is described by a renormalization group improved Vaidya metric. Its event horizon, apparent horizon, and timelike limit surface are obtained taking the scale dependence of Newton's constant into account. The emergence of a quantum ergosphere is discussed. The final state of the evaporation process is a cold, Planck size remnant.Comment: 23 pages, BibTeX, revtex4, 7 figure

Thermodynamic cyclic voltammograms: peak positions and shapes

Based on a mean-field description of thermodynamic cyclic voltammograms (CVs), we analyse here in full generality, how CV peak positions and shapes are related to the underlying interface energetics, in particular when also including electrostatic double layer (DL) effects. We show in particular, how non-Nernstian behaviour is related to capacitive DL charging, and how this relates to common adsorbate-centered interpretations such as a changed adsorption energetics due to dipole-field interactions and the electrosorption valency - the number of exchanged electrons upon electrosorption per adsorbate. Using Ag(111) in halide-containing solutions as test case, we demonstrate that DL effects can introduce peak shifts that are already explained by rationalizing the interaction of isolated adsorbates with the interfacial fields, while alterations of the peak shape are mainly driven by the coverage-dependence of the adsorbate dipoles. In addition, we analyse in detail how changing the experimental conditions such as the ion concentrations in the solvent but also of the background electrolyte can affect the CV peaks via their impact on the potential drop in the DL and the DL capacitance, respectively. These results suggest new routes to analyse experimental CVs and use of those for a detailed assessment of the accuracy of atomistic models of electrified interfaces e.g. with and without explicitly treated interfacial solvent and/or approximate implicit solvent models

Electrosorption at metal surfaces from first principles

Electrosorption of solvated species at metal electrodes is a most fundamental class of processes in interfacial electrochemistry. Here, we use its sensitive dependence on the electric double layer to assess the performance of ab initio thermodynamics approaches increasingly used for the first-principles description of electrocatalysis. We show analytically that computational hydrogen electrode calculations at zero net-charge can be understood as a first-order approximation to a fully grand canonical approach. Notably, higher-order terms in the applied potential caused by the charging of the double layer include contributions from adsorbate-induced changes in the work function and in the interfacial capacitance. These contributions are essential to yield prominent electrochemical phenomena such as non-Nernstian shifts of electrosorption peaks and non-integer electrosorption valencies. We illustrate this by calculating peak shifts for H on Pt electrodes and electrosorption valencies of halide ions on Ag electrodes, obtaining qualitative agreement with experimental data already when considering only second order terms. The results demonstrate the agreement between classical electrochemistry concepts and a first-principles fully grand canonical description of electrified interfaces and shed new light on the widespread computational hydrogen electrode approach

Comparison of Renormalization-Group and Lattice Studies of the Electroweak Phase Transition

We compare the results of renormalization-group and lattice studies for the properties of the electroweak phase transition. This comparison reveals the mechanisms that underlie the phenomenology of the phase transition.Comment: 13 pages, 3 figure

Is Quantum Einstein Gravity Nonperturbatively Renormalizable?

We find considerable evidence supporting the conjecture that four-dimensional Quantum Einstein Gravity is ``asymptotically safe'' in Weinberg's sense. This would mean that the theory is likely to be nonperturbatively renormalizable and thus could be considered a fundamental (rather than merely effective) theory which is mathematically consistent and predictive down to arbitrarily small length scales. For a truncated version of the exact flow equation of the effective average action we establish the existence of a non-Gaussian renormalization group fixed point which is suitable for the construction of a nonperturbative infinite cutoff-limit. The truncation ansatz includes the Einstein-Hilbert action and a higher derivative term.Comment: 18 pages, latex, 3 figure

Critical Exponents from the Effective Average Action

We compute the critical behaviour of three-dimensional scalar theories using a new exact non-perturbative evolution equation. Our values for the critical exponents agree well with previous precision estimates.Comment: 46 pages, 3 figures available by fax upon request, preprint DESY 93-094, HD-THEP-93-2