Supersymmetric D0-Branes in Curved Backgrounds

An action for supersymmetric D0-branes in curved backgrounds is obtained by dimensional reduction of N=1 ten-dimensional supergravity coupled to super Yang-Mills system to 0+1 dimensions. The resultant action exhibits the coset-space symmetry $\frac{SO(9,9+n)}{SO(9)\times SO(9+n)}\times U(1)$ where $n=N^{2}-1$ is the dimension of the SU(N) gauge group.Comment: 8 pages. One reference and a comment adde

Coherent phenomena in mesoscopic systems

A mesoscopic system of cylindrical geometry made of a metal or a semiconductor is shown to exhibit features of a quantum coherent state. It is shown that magnetostatic interaction can play an important role in mesoscopic systems leading to an ordered ground state. The temperature $T^{*}$ below the system exhibits long-range order is determined. The self-consistent mean field approximation of the magnetostatic interaction is performed giving the effective Hamiltonian from which the self-sustaining currents can be obtained. The relation of quantum coherent state in mesoscopic cylinders to other coherent systems like superconductors is discussed.Comment: REVTeX, 4 figures, in print in Supercond. Sci. Techno

Renal involvement follows cardiac enlargement in essential hypertension

To assess the relationship between early clinically detectable involvement of hypertensive vascular disease in heart and kidneys, we obtained systemic and renal hemodynamic and M-mode echocardiographic measurements in 65 patients with essential hypertension. The results indicate that patients with and without left ventricular hypertrophy had similar renal hemodynamic findings. In contrast, patients with altered renal hemodynamic measurements (ie, reduced renal distribution of cardiac output and, therefore, absolute renal blood flow with increased renal vascular resistance) and increased serum uric acid levels also had increased left ventricular posterior and septal wall thicknesses and mass index. Moreover, these data also demonstrated that in patients with altered renal hemodynamics, the lower the renal distribution of cardiac output and the higher the serum uric acid levels, the greater were the indexes of cardiac enlargement. These results demonstrated that the pathophysiological and hemodynamic effects of essential hypertension in the heart precede those in the kidneys

On Abelian Multi-Chern-Simons Field Theories

In this paper a class of multi-Chern-Simons field theories which is relevant to the statistical mechanics of polymer systems is investigated. Motivated by the problems which one encounters in the treatment of these theories, a general procedure is presented to eliminate the Chern-Simons fields from their action. In this way it has been possible to derive an expression of the partition function of topologically linked polymers which depends explicitly on the topological numbers and does not have intractable nonlocal terms as it happened in previous approaches. The new formulation of multi-Chern-Simons field theories is then used to remove and clarify some inconsistencies and ambiguities which apparently affect field theoretical models of topologically linked polymers. Finally, the limit of disentangled polymers is discussed.Comment: 18 pages, plain LaTe

Microbiology and atmospheric processes: Biological, physical and chemical characterization of aerosol particles

The interest in bioaerosols has traditionally been linked to health hazards for humans, animals and plants. However, several components of bioaerosols exhibit physical properties of great significance for cloud processes, such as ice nucleation and cloud condensation. To gain a better understanding of their influence on climate, it is therefore important to determine the composition, concentration, seasonal fluctuation, regional diversity and evolution of bioaerosols. In this paper, we will review briefly the existing techniques for detection, quantification, physical and chemical analysis of biological particles, attempting to bridge physical, chemical and biological methods for analysis of biological particles and integrate them with aerosol sampling techniques. We will also explore some emerging spectroscopy techniques for bulk and single-particle analysis that have potential for in-situ physical and chemical analysis. Lastly, we will outline open questions and further desired capabilities (e. g., in-situ, sensitive, both broad and selective, on-line, time-resolved, rapid, versatile, cost-effective techniques) required prior to comprehensive understanding of chemical and physical characterization of bioaerosols

High AIDS-related mortality among young women in rural KwaZulu-Natal

Objective. To establish mortality rates and cause of death in a rural community in KwaZulu-Natal. This study was conducted as part of a demographic and health survey to assess the impact of HIV infection in this community. Methods. A cross-sectional survey was conducted between February and July 2004. The survey made use of structured questionnaires and verbal autopsies, which yielded detailed information at household level, including the demographic profile of residents, mortality rates and cause of mortality between February 2003 and February 2004.Results. The overall mortality rate in this community was 2.9 deaths per 100 person-years (95% confidence interval (CI): 2.5 - 3.3 per 100 person-years). The highest mortality rate among women occurred in the 30 - 34-year age group, while among men it occurred in the 35 - 39 and > 60-year age groups. Of the 185 verbal autopsies reported, 77 deaths (42%) were attributable to AIDS. The survey revealed that women aged 20 - 24 and men aged 35 - 39 years were bearing a disproportionately large burden of AIDS-related mortality in this community.Conclusion. AIDS-related mortality was found to be disproportionately high in young women in this small rural community, and the majority of deaths resulted from pulmonary tuberculosis. The need to strengthen prevention and treatment efforts in this and similar settings is highlighted

Co-designing Community Infrastructure in Dwenase, Ghana

The goal of this project was to create a drainage system for the parking lot of the Dwenase Health Center. During the rainy season the area in front of the Center became flooded by rains flowing in from the road and poor parking lot grading. As engineers, we have had experience with designing, but we lack the regional understanding and expertise of the local residents. For this project, then, we utilized our experience as designers while incorporating their knowledge of the problem. Co-design involves a free exchange of ideas between partners. We thought we were co-designing with the community. However, they were co-designing us. This applied to our work and our personal lives. Thus, knowledge flows both ways—even when do not think we are coproducing, we are

Effect of quantum lattice fluctuations on the optical-absorption spectra of halogen-bridged mixed-valence transition-metal complexes

The effect of quantum lattice fluctuations on the optical-absorption spectra in the ground state of halogen-bridged mixed-valence transition-metal linear-chain complexes is studied by using a one-dimensional extended Peierls-Hubbard model. The nonadiabatic effects due to finite phonon frequency $\omega_{\pi}>0$ are treated through an energy-dependent electron-phonon scattering function $\delta(k^{\prime},k)$ introduced by means of an unitary transformation. The calculated optical-absorption spectra do not have the inverse-square-root singularity, but they have a peak above the gap edge and there exists a significant tail below the peak, which are consistent with the optical-absorption coefficient or the optical conductivity measurements of this material.Comment: 10 pages, 6 figure

Degree spectra for transcendence in fields

We show that for both the unary relation of transcendence and the finitary relation of algebraic independence on a field, the degree spectra of these relations may consist of any single computably enumerable Turing degree, or of those c.e. degrees above an arbitrary fixed $\Delta^0_2$ degree. In other cases, these spectra may be characterized by the ability to enumerate an arbitrary $\Sigma^0_2$ set. This is the first proof that a computable field can fail to have a computable copy with a computable transcendence basis