28 research outputs found
Potential cost savings with terrestrial rabies control
BACKGROUND: The cost-benefit of raccoon rabies control strategies such as oral rabies vaccination (ORV) are under evaluation. As an initial quantification of the potential cost savings for a control program, the collection of selected rabies cost data was pilot tested for five counties in New York State (NYS) in a three-year period. METHODS: Rabies costs reported to NYS from the study counties were computerized and linked to a human rabies exposure database. Consolidated costs by county and year were averaged and compared. RESULTS: Reported rabies-associated costs for all rabies variants totalled 784,529). Average costs associated with the raccoon variant varied across counties from 1,885 per PEP, 44 per specimen, and 15 per pet vaccinated. CONCLUSION: Rabies costs vary widely by county in New York State, and were associated with human population size and methods used by counties to estimate costs. Rabies cost variability must be considered in developing estimates of possible ORV-related cost savings. Costs of PEPs and specimen preparation/shipments, as well as the costs of pet vaccination provided by this study may be valuable for development of more realistic scenarios in economic modelling of ORV costs versus benefits
Evolutionary History of Rabies in Ghana
Rabies virus (RABV) is enzootic throughout Africa, with the domestic dog (Canis familiaris) being the principal vector. Dog rabies is estimated to cause 24,000 human deaths per year in Africa, however, this estimate is still considered to be conservative. Two sub-Saharan African RABV lineages have been detected in West Africa. Lineage 2 is present throughout West Africa, whereas Africa 1a dominates in northern and eastern Africa, but has been detected in Nigeria and Gabon, and Africa 1b was previously absent from West Africa. We confirmed the presence of RABV in a cohort of 76 brain samples obtained from rabid animals in Ghana collected over an eighteen-month period (2007–2009). Phylogenetic analysis of the sequences obtained confirmed all viruses to be RABV, belonging to lineages previously detected in sub-Saharan Africa. However, unlike earlier reported studies that suggested a single lineage (Africa 2) circulates in West Africa, we identified viruses belonging to the Africa 2 lineage and both Africa 1 (a and b) sub-lineages. Phylogeographic Bayesian Markov chain Monte Carlo analysis of a 405 bp fragment of the RABV nucleoprotein gene from the 76 new sequences derived from Ghanaian animals suggest that within the Africa 2 lineage three clades co-circulate with their origins in other West African countries. Africa 1a is probably a western extension of a clade circulating in central Africa and the Africa 1b virus a probable recent introduction from eastern Africa. We also developed and tested a novel reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of RABV in African laboratories. This RT-LAMP was shown to detect both Africa 1 and 2 viruses, including its adaptation to a lateral flow device format for product visualization. These data suggest that RABV epidemiology is more complex than previously thought in West Africa and that there have been repeated introductions of RABV into Ghana. This analysis highlights the potential problems of individual developing nations implementing rabies control programmes in the absence of a regional programme
Constraints on olivine-rich rock types on the Moon as observed by Diviner and M 3 : Implications for the formation of the lunar crust
We place upper limits on lunar olivine abundance using midinfrared (5–25 µm) data from the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment (Diviner) along with effective emissivity spectra of mineral mixtures in a simulated lunar environment. Olivine-bearing, pyroxene-poor lithologies have been identified on the lunar surface with visible-near-infrared (VNIR) observations. Since the Kaguya Spectral Profiler (SP) VNIR survey of olivine-rich regions is the most complete to date, we focus this work on exposures identified by that study. We first confirmed the locations with VNIR data from the Moon Mineralogy Mapper (M3) instrument. We then developed a Diviner olivine index from our laboratory data which, along with M3and Lunar Reconnaissance Orbiter Camera wide-angle camera data, was used to select the geographic area over which Diviner emissivity data were extracted. We calculate upper limits on olivine abundance for these areas using laboratory emissivity spectra of anorthite-forsterite mixtures acquired under lunar-like conditions. We find that these exposures have widely varying olivine content. In addition, after applying an albedo-based space weathering correction to the Diviner data, we find that none of the areas are unambiguously consistent with concentrations of forsterite exceeding 90 wt %, in contrast to the higher abundance estimates derived from VNIR data
Space weathering effects in Diviner Lunar Radiometer multispectral infrared measurements of the lunar Christiansen Feature: Characteristics and mitigation
Multispectral infrared measurements by the Diviner Lunar Radiometer Experiment on the Lunar Renaissance Orbiter enable the characterization of the position of the Christiansen Feature, a thermal infrared spectral feature that laboratory work has shown is proportional to the bulk silica content of lunar surface materials. Diviner measurements show that the position of this feature is also influenced by the changes in optical and physical properties of the lunar surface with exposure to space, the process known as space weathering. Large rayed craters and lunar swirls show corresponding Christiansen Feature anomalies. The space weathering effect is likely due to differences in thermal gradients in the optical surface imposed by the space weathering control of albedo. However, inspected at high resolution, locations with extreme compositions and Christiansen Feature wavelength positions – silica-rich and olivine-rich areas – do not have extreme albedos, and fall off the albedo- Christiansen Feature wavelength position trend occupied by most of the Moon. These areas demonstrate that the Christiansen Feature wavelength position contains compositional information and is not solely dictated by albedo. An optical maturity parameter derived from near-IR measurements is used to partly correct Diviner data for space weathering influences
Space weathering effects in Diviner Lunar Radiometer multispectral infrared measurements of the lunar Christiansen Feature: Characteristics and mitigation
Multispectral infrared measurements by the Diviner Lunar Radiometer Experiment on the Lunar Renaissance Orbiter enable the characterization of the position of the Christiansen Feature, a thermal infrared spectral feature that laboratory work has shown is proportional to the bulk silica content of lunar surface materials. Diviner measurements show that the position of this feature is also influenced by the changes in optical and physical properties of the lunar surface with exposure to space, the process known as space weathering. Large rayed craters and lunar swirls show corresponding Christiansen Feature anomalies. The space weathering effect is likely due to differences in thermal gradients in the optical surface imposed by the space weathering control of albedo. However, inspected at high resolution, locations with extreme compositions and Christiansen Feature wavelength positions – silica-rich and olivine-rich areas – do not have extreme albedos, and fall off the albedo- Christiansen Feature wavelength position trend occupied by most of the Moon. These areas demonstrate that the Christiansen Feature wavelength position contains compositional information and is not solely dictated by albedo. An optical maturity parameter derived from near-IR measurements is used to partly correct Diviner data for space weathering influences
Highly silicic compositions on the Moon.
Using data from the Diviner Lunar Radiometer Experiment, we show that four regions of the Moon previously described as "red spots" exhibit mid-infrared spectra best explained by quartz, silica-rich glass, or alkali feldspar. These lithologies are consistent with evolved rocks similar to lunar granites in the Apollo samples. The spectral character of these spots is distinct from surrounding mare and highlands material and from regions composed of pure plagioclase feldspar. The variety of landforms associated with the silicic spectral character suggests that both extrusive and intrusive silicic magmatism occurred on the Moon. Basaltic underplating is the preferred mechanism for silicic magma generation, leading to the formation of extrusive landforms. This mechanism or silicate liquid immiscibility could lead to the formation of intrusive bodies
Effect of pH on turbidity, size, viscosity and the shape of sodium caseinate aggregates with light scattering and rheometry
Global silicate mineralogy of the Moon from the Diviner lunar radiometer.
We obtained direct global measurements of the lunar surface using multispectral thermal emission mapping with the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment. Most lunar terrains have spectral signatures that are consistent with known lunar anorthosite and basalt compositions. However, the data have also revealed the presence of highly evolved, silica-rich lunar soils in kilometer-scale and larger exposures, expanded the compositional range of the anorthosites that dominate the lunar crust, and shown that pristine lunar mantle is not exposed at the lunar surface at the kilometer scale. Together, these observations provide compelling evidence that the Moon is a complex body that has experienced a diverse set of igneous processes