Community knowledge variation, bed-net coverage, the role of a district health care system and their implications for malaria control in Southern Malawi

This paper presents data on the pattern of knowledge of caregivers, bed-net coverage and the role of a rural district healthcare system, and their implications for malaria transmission, treatment, prevention and control in Chikhwawa, southern Malawi, using multi-level logistic regression modelling with Bayesian estimation. The majority of caregivers could identify the main symptoms of malaria, that the mosquito was the vector, and that insecticide-treated nets (ITN) could be used to cover beds as an effective preventative measure, although cost was a prohibitive factor. Use of bed nets displayed significant variation between communities. Groups that were more knowledgeable on malaria prevention and symptoms included young mothers, people who had attended school, wealthy individuals, those residing closest to government hospitals and health posts, and communities that had access to a health surveillance assistant (HSA). HSAs should be trained on malaria intervention programmes, and tasked with the responsibility of working with village health committees to develop community-based malaria intervention programmes. These programmes should include appropriate and affordable household improvement methods, identification of high-risk groups, distribution of ITNs and the incorporation of larval control measures, to reduce exposure to the vector and parasite. This would reduce the transmission and prevalence of malaria at community level

Resistively Detected NMR in Quantum Hall States: Investigation of the anomalous lineshape near ν=1\nu=1

A study of the resistively detected nuclear magnetic resonance (RDNMR) lineshape in the vicinity of $\nu=1$ was performed on a high-mobility 2D electron gas formed in GaAs/AlGaAs. In higher Landau levels, application of an RF field at the nuclear magnetic resonance frequency coincides with an observed minimum in the longitudinal resistance, as predicted by the simple hyperfine interaction picture. Near $\nu=1$ however, an anomalous dispersive lineshape is observed where a resistance peak follows the usual minimum. In an effort to understand the origin of this anomalous peak we have studied the resonance under various RF and sample conditions. Interestingly, we show that the lineshape can be completely inverted by simply applying a DC current. We interpret this as evidence that the minima and maxima in the lineshape originate from two distinct mechanisms.Comment: 5 pages, 3 figures, EP2DS 17, to be published in Physica

Breakdown of Particle-Hole Symmetry in the Lowest Landau Level Revealed by Tunneling Spectroscopy

Tunneling measurements on 2D electron gases at high magnetic field reveal a qualitative difference between the two spin sublevels of the lowest Landau level. While the tunneling current-voltage characteristic at filling factor $\nu = 1/2$ is a single peak shifted from zero bias by a Coulomb pseudogap, the spectrum at $\nu=3/2$ shows a well-resolved double peak structure. This difference is present regardless of whether $\nu =1/2$ and $\nu = 3/2$ occur at the same or different magnetic fields. No analogous effect is seen at $\nu = 5/2$ and 7/2 in the first excited Landau level.Comment: 5 pages, 4 figure

Evidence for a Population of High-Redshift Submillimeter Galaxies from Interferometric Imaging

We have used the Submillimeter Array to image a flux-limited sample of seven submillimeter galaxies, selected by the AzTEC camera on the JCMT at 1.1 mm, in the COSMOS field at 890 μm with ∼2″ resolution. All of the sources - two radio-bright and five radio-dim - are detected as single point sources at high significance (\u3e6 σ), with positions accurate to ∼0.2″ that enable counterpart identification at other wavelengths observed with similarly high angular resolution. All seven have IRAC counterparts, but only two have secure counterparts in deep HST ACS imaging. As compared to the two radio-bright sources in the sample, and those in previous studies, the five radio-dim sources in the sample (1) have systematically higher submillimeter-to-radio flux ratios, (2) have lower IRAC 3.6-8.0 μm fluxes, and (3) are not detected at 24 μm. These properties, combined with size constraints at 890 μm (θ ≲ 1.2″), suggest that the radio-dim submillimeter galaxies represent a population of very dusty starbursts, with physical scales similar to local ultraluminous infrared galaxies, with an average redshift higher than radio-bright sources

Origins of the Ambient Solar Wind: Implications for Space Weather

The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

Investigation of Cavity Flow Using Fast-Response Pressure Sensitive Paint

An experimental study was conducted to investigate the pressure fluctuations on the entire side wall of a rectangular cavity with an L/D of 5.67 using fast-response pressure sensitive paint. Additionally, the performance of four different passive flow-control devices was quantified. Experiments were conducted in the Trisonic Gasdynamics Facility at the Air Force Research Laboratory at Mach 0.7 and 1.5. The frequency spectrum (including Rossiter tones) and sound pressure levels (SPLs) obtained from the pressure sensitive paint (PSP) measurements are validated against data taken with conventional dynamic pressure sensors. The complex flow phenomena over the cavity wall were visualized, and full wall pressure spectra were calculated. The rod in cross flow showed the best peak suppression, followed closely by the flat spoiler. The large triangular step showed some peak suppression, while the ridges did not suppress the peaks at all. High resolution measurements of pressure fluctuations on the wall allowed for the visualization of SPL distribution over the entire cavity wall. This revealed a strong dependence between the Rossiter tone modes and the spatial distribution of SPL that was not possible to resolve with discrete pressure transducers