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Albuquerque, NM, United States

Metzler D.,Albuquerque Academy
Quaestiones Geographicae

We introduce three related mathematical measures of terrain based on a particularly elegant combination of relief and steepness, which we term omnidirectional relief and steepness (ORS). One measure, reduced ORS (RORS), is particularly suited to creating lists of notable features, and another, domain relief and steepness (DRS), measures the ruggedness of a region. © 2015 Faculty of Geographical and Geological Sciences, Adam Mickiewicz University. Source

Ollila A.M.,University of New Mexico | Newsom H.E.,University of New Mexico | Clark III B.,Space Science Institute | Wiens R.C.,Los Alamos National Laboratory | And 29 more authors.
Journal of Geophysical Research E: Planets

The ChemCam instrument package on the Mars rover, Curiosity, provides new capabilities to probe the abundances of certain trace elements in the rocks and soils on Mars using the laser-induced breakdown spectroscopy technique. We focus on detecting and quantifying Li, Ba, Rb, and Sr in targets analyzed during the first 100 sols, from Bradbury Landing Site to Rocknest. Univariate peak area models and multivariate partial least squares models are presented. Li, detected for the first time directly on Mars, is generally low (<15 ppm). The lack of soil enrichment in Li, which is highly fluid mobile, is consistent with limited influx of subsurface waters contributing to the upper soils. Localized enrichments of up to ~60 ppm Li have been observed in several rocks but the host mineral for Li is unclear. Bathurst-Inlet is a fine-grained bedrock unit in which several analysis locations show a decrease in Li and other alkalis with depth, which may imply that the unit has undergone low-level aqueous alteration that has preferentially drawn the alkalis to the surface. Ba (~1000 ppm) was detected in a buried pebble in the Akaitcho sand ripple and it appears to correlate with Si, Al, Na, and K, indicating a possible feldspathic composition. Rb and Sr are in the conglomerate Link at abundances >100 ppm and >1000 ppm, respectively. These analysis locations tend to have high Si and alkali abundances, consistent with a feldspar composition. Together, these trace element observations provide possible evidence of magma differentiation and aqueous alteration. Key Points Quantitative models for Li, Ba, Rb and Sr using ChemCam data are presented Abundances for the first 100 sols in Gale crater are discussed These results represent the first in situ measurements of Li and Ba on Mars ©2013. American Geophysical Union. All Rights Reserved. Source

Plumley J.B.,University of New Mexico | Akins B.A.,University of New Mexico | Alas G.J.,University of New Mexico | Fetrow M.E.,University of New Mexico | And 10 more authors.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE

Quantum dots (QDs) are of high interest in the biomedical field. The most widely used and commercially available CdSe/ZnS QDs have a highly toxic Cd component. High-efficiency luminescent Cd-free Mn-doped ZnSe/ZnS QDs are a reasonable alternative to CdSe/ZnS QDs; however the actual cytotoxicity of ZnSe:Mn/ZnS QDs is relatively unknown. In this study, we apply the ApoTox-GloTM Triplex assay to test for cell cytotoxicity, viability, and induced apoptosis, by treating macrophage cells with different concentrations of peptide-coated ZnSe:Mn/ZnS QDs at four different incubation times: 6, 12, 24, and 48 hours. At the concentrations used, which varied between 0.03 μM to 0.25 μM, the macrophage cells showed very little cytotoxic effect. However, cell viability began to decrease with increasing QD concentration beginning with the 12 hour incubation time, with fairly consistent results for 24 and 48 hour incubation times as well. Also, the macrophage cells expressed a measurable degree of induced apoptosis, which scaled with concentration. While cytotoxicity did not seem to be an issue with macrophage cells treated with the peptide-coated Mn-doped ZnSe/ZnS QDs, the drop in cell viability and the increase in induced apoptosis suggest an antiproliferation effect within the macrophage cell culture. © 2014 SPIE. Source

Tian Y.,Sandia National Laboratories | Tian Y.,University of New Mexico | Martin K.E.,Sandia National Laboratories | Martin K.E.,University of New Mexico | And 7 more authors.
Chemical Communications

Varying the solution growth conditions of cooperative binary ionic solids composed of anionic and cationic metalloporphyrins produces a series of families of self-assembled structures that efficiently and durably photosensitize the evolution of hydrogen. © 2011 The Royal Society of Chemistry. Source

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