Effect of Fertilizer on Leaf Tensile Strength in Salvia Leucophylla

This experiment sought to establish a connection between short term growth in Salvia leucophylla found in Southern California and nutrient availability in the soil. It was hypothesized that adding artificially produced nutrient mix Miracle Grow would increase the strength of the leaves in the herb after one week of addition. Newer leaves were tested in the Instron device for tensile strength after one week, and after data analysis, it was concluded that there was no difference in tensile strength of leaves treated with fertilizer compared with leaves without fertilizer

Dimensional Change of Denture PMMA Processed to CAD/CAM Produced Denture Bases

Purpose: The purpose of this study was to carry out a three-dimensional analysis of the processing distortion that occurs when acrylic resin and teeth are processed onto two types of CAD/CAM denture bases. Previous studies used analog methods of measurement, and have not examined CAD/CAM denture base distortion after processing. Materials and Methods: Ten milled and printed denture bases were fabricated on an edentulous cast, the intaglio surface scanned, and then a second processing step with acrylic resin and teeth was performed to finish fabrication of complete dentures. The samples were scanned a second time after the second processing step and then both pre- and post-processed STL files of the intaglio surface were compared with the original design file by digital file superimposition to record distortion in twelve anatomic regions. Results: Both milled and printed denture bases had statistically significant changes (p<.001) after processing. Milled denture bases had an average deviation from the design file before processing of -82.5 µm and -2.3 µm after. Printed denture bases had an average deviation from the design file before processing of -100.2 µm and 23.3 µm after. Comparison between denture base groups showed a significant difference (p<.05) in distortion; milled denture bases distorted less than printed denture bases. Conclusions: There was a significant difference in denture bases after processing regardless of fabrication method, with more distortion seen in printed denture bases. This difference, while statistically significant, may not be clinically significant. The area of the smallest distortion after processing was the posterior palatal seal for both milled and printed denture bases. The area of greatest distortion after processing for the printed bases was the tuberosity region, for the milled bases the mid palate region exhibited the greatest value of distortion

New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope

We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 JY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of ~0.02 arcsec (~700 km at 44 AU) and {\Delta}m less than or equal to 0.5.Comment: Pages: 11, Figures: 2, Tables: 3, Icarus, available online May 2014 (http://dx.doi.org/10.1016/j.icarus.2014.04.014

Effects of UV Light on Local Stream Frog Behavior

Amphibian declines have been well documented throughout the world. Several studies have examined whether UV radiation from the sun is a possible contributing cause to declining populations. In Southern California, two closely related species of treefrogs, Pseudacris hypochondriaca and Pseudacris cadaverina, coexist in many perennial streams. P. hypochondriaca is primarily nocturnal while P. cadaverina is known to bask in direct sunlight. The purpose of the study is to determine how the two different species of frogs will react under different types of light emitted by a portable flashlight. The light was emitting either UV radiation or visible light, or was turned off as it was slowly brought toward the frog. When the frog jumped from its resting position, the light was held stationary and the distance from the light to the original frog perch was recorded. Our results suggest that both species are more sensitive to the UV light than to the light that was turned off or the visible light. Frogs jumped much sooner when presented with UV even the light was farther away from them. There appeared to be no differences in the sensitivity of the two species to the UV light. Our results suggest that both species of treefrogs are sensitive to UV. This sensitivity may be due in part to the large levels of UV that reach streams after wildfires. Wildfires are a natural part of these ecosystems and the removal of tree canopy by wildfire may create periodic strong selection on riparian animals to avoid increased levels of UV radiation