Adjoints of elliptic cone operators

We study the adjointness problem for the closed extensions of a general b-elliptic operator A in x^{-\nu}Diff^m_b(M;E), \nu>0, initially defined as an unbounded operator A:C_c^\infty(M;E)\subset x^\mu L^2_b(M;E)\to x^\mu L^2_b(M;E), \mu \in \R. The case where A is a symmetric semibounded operator is of particular interest, and we give a complete description of the domain of the Friedrichs extension of such an operator.Comment: 40 pages, LaTeX, preliminary versio

Monitoring and evaluation in global HIV/AIDS control - weighing incentives and disincentives for coordination among global and local actors

This paper discusses coordination efforts of both donors and recipient countries in the monitoring and evaluation (M&E) of health outcomes in the field of HIV/AIDS. The coordination of M&E is a much underdeveloped area in HIV/AIDS programming in which, however, important first steps towards better synchronisation have already been taken. In this paper, we review the concepts and meanings commonly applied to M&E, and approaches and strategies for better coordination of M&E in the field of HIV/AIDS. Most importantly, drawing on this analysis, we examine why the present structure of global health governance in this area is not creating strong enough incentives for effective coordination among global and local actors. Copyright © 2010 John Wiley & Sons, Ltd

Influence of Dimensionality on Thermoelectric Device Performance

The role of dimensionality on the electronic performance of thermoelectric devices is clarified using the Landauer formalism, which shows that the thermoelectric coefficients are related to the transmission, T(E), and how the conducing channels, M(E), are distributed in energy. The Landauer formalism applies from the ballistic to diffusive limits and provides a clear way to compare performance in different dimensions. It also provides a physical interpretation of the "transport distribution," a quantity that arises in the Boltzmann transport equation approach. Quantitative comparison of thermoelectric coefficients in one, two, and three dimension shows that the channels may be utilized more effectively in lower-dimensions. To realize the advantage of lower dimensionality, however, the packing density must be very high, so the thicknesses of the quantum wells or wires must be small. The potential benefits of engineering M(E) into a delta-function are also investigated. When compared to a bulk semiconductor, we find the potential for ~50 % improvement in performance. The shape of M(E) improves as dimensionality decreases, but lower dimensionality itself does not guarantee better performance because it is controlled by both the shape and the magnitude of M(E). The benefits of engineering the shape of M(E) appear to be modest, but approaches to increase the magnitude of M(E) could pay large dividends.Comment: 23 pages, 5 figure

The Denial of Politics in PRSP’s Monitoring and Evaluation. Experiences From Rwanda

The new development paradigm strongly reconfirms and redefines the importance of M&E because of some newly incorporated principles. First, increased value is attached to results-orientation, iterative learning and evidence-based policy-making. Realisation of these principles is conditional upon a strong and well-functioning M&E system. A second major principle is an increased role and responsibility for the national government in elaborating and managing the entire M&E system. At the same time, donors are expected to increasingly rely and align to national M&E systems and arrangements. So far, however, a narrowly confined ‘technocratic’ approach to M&E has been adopted, largely neglecting its institutional and political embeddedness. While the fact that politics are part and parcel of M&E has been acknowledged before in the context of projects and programmes, it seems that when moving to the sectoral and national level (where interests and stakeholders are multiplied) the interaction among ‘politics’ and ‘M&E’ is disregarded. This paper elaborates a conceptual framework that furthers the understanding of the interlinkages among politics and M&E in a context of upwardly moving aid modalities. Bringing in case-study material from Rwanda, it argues that a narrow technocratic approach to M&E risks worsening political constraints and even undermines M&E’s technical soundness. Yet, there exist ways of escaping this downward spiral. ‘Smart’ M&E that acknowledges the institutional and political embeddedness of M&E has the leverage to stimulate public discussion, to bring more ‘sensitive’ issues into the bargaining area, to shift debates on a more factual basis and to eventually open up closed political opportunity structures.

Global Dimension of Polynomial Rings in Partially Commuting Variables

For any free partially commutative monoid $M(E,I)$, we compute the global dimension of the category of $M(E,I)$-objects in an Abelian category with exact coproducts. As a corollary, we generalize Hilbert's Syzygy Theorem to polynomial rings in partially commuting variables.Comment: 11 pages, 2 figure

Dimensionless Measures of Turbulent Magnetohydrodynamic Dissipation Rates

The magnetic Reynolds number R_M, is defined as the product of a characteristic scale and associated flow speed divided by the microphysical magnetic diffusivity. For laminar flows, R_M also approximates the ratio of advective to dissipative terms in the total magnetic energy equation, but for turbulent flows this latter ratio depends on the energy spectra and approaches unity in a steady state. To generalize for flows of arbitrary spectra we define an effective magnetic dissipation number, R_{M,e}, as the ratio of the advection to microphysical dissipation terms in the total magnetic energy equation, incorporating the full spectrum of scales, arbitrary magnetic Prandtl numbers, and distinct pairs of inner and outer scales for magnetic and kinetic spectra. As expected, for a substantial parameter range R_{M,e}\sim {O}(1) << R_M. We also distinguish R_{M,e} from {\tilde R}_{M,e} where the latter is an effective magnetic Reynolds number for the mean magnetic field equation when a turbulent diffusivity is explicitly imposed as a closure. That R_{M,e} and {\tilde R}_{M,e} approach unity even if R_M>>1 highlights that, just as in hydrodynamic turbulence,energy dissipation of large scale structures in turbulent flows via a cascade can be much faster than the dissipation of large scale structures in laminar flows. This illustrates that the rate of energy dissipation by magnetic reconnection is much faster in turbulent flows, and much less sensitive to microphysical reconnection rates compared to laminar flows.Comment: 14 pages (including 2 figs), accepted by MNRA

Weyl-type Fields with Geodesic Lines of Force

The static electrogravitational equations are studied and it is shown that an aligned type D metric which has a Weyl-type relationship between the gravitational and electric potential has shearfree geodesic lines of force. All such fields are then found and turn out to be the fields of a charged sphere, charged infinite rod and charged infinite plate. A further solution is also found with shearing geodesic lines of force. This new solution can have $m>|e|$ or $m<|e|$, but cannot be in the Majumdar-Papapetrou class (in which $m = |e|$). It is algebraically general and has flat equipotential surfaces.Comment: 13 pages, RevTe