The dwarf galaxies orbiting the Milky Way seem to lie along a geometric plane. These observations are not consistent with expectations from cosmological simulations. We integrated theseå orbits into the past based on data from the Hubble Space Telescope to look at how the plane has changed and for possible causes of this structure.
Undergraduate students Matthew Wheatley and Alexander Triassi in the Hudson/Savka lab recently presented their research at the annual American Society for Microbiology (ASM) (http://www.asm.org//) in Boston, MA from May 17-May 20, 2014. Matthew presented his research on the isolation and identification of bacterial endophytes from willow plants (http://www.ncbi.nlm.nih.gov/pubmed/24812212) and Alex presented his research on a novel lysine biosynthesis pathway as a target for antibiotic development (http://www.ncbi.nlm.nih.gov/pubmed/24268540).
Student Author: Matthew Wheatley, Alexander Triassi
Mapping and monitoring our world are increasingly moving from flat 2-dimensional representations to 3-dimensional visualizations, particularly in urban settings. As part of an NSF-funded collaborative project with Pictometry International, researchers in the Chester F. Carlson Center for Imaging Science are exploring ways to automatically generate 3D building models from point cloud data derived from oblique aerial imagery and lidar data. The figure above shows an example of (a) 3D point cloud data for a building and (b) a computer aided design (CAD) model automatically derived from the point cloud data. These building models can then be overlaid with imagery to develop full 3D visualizations for urban planning, tourism, and city walk-throughs, in addition to many other applications.
Using the new Gemini Planet Imager instrument on the Gemini South telescope, astronomers at RIT have discovered striking new evidence for planet formation in a dusty disk surrounding a pair of stars in Sagittarius. The image above, which shows light scattered off small dust grains around the young stellar system V4046 Sgr, reveals an intriguing double ring structure, likely due to giant planet formation. These planets would orbit V4046 Sgr at distances similar to Saturn and Uranus in our own solar system, and is perhaps the best such evidence yet for planet formation so close to a binary system.
Zero valued points in physics are often of great interest to scientists. The system properties near the zero point may differ from the properties in other regions. Our team has been exploring how the intensity of light can destructively interfere - not at a single point - but over an extended region in space. We call such regions “nodal areas”. Our recent paper in the high impact OSA journal, Optica, describes how to create nodal areas by use of a non-absorbing refractive optical mask. We also describe how this intriguing phenomenon can be used to form high contrast imaging systems for the direct observation of exoplanets. The figure below show a numerically generated image of a nodal area in the shape of a star.
The similarity of air pressure and radiation (or light) pressure begs the question: does an optical analogue to the airfoil exist, and how does the shape of such an optical wing affect desired motion? In this research, refractive rods with asymmetric cross-sections are designed, fabricated, and studied as optical analogues to aerodynamic wings. Development of optical wings builds an infrastructure for future micromanipulation of shaped objects and novel space flight applications.
Peptidoglycan associated lipoprotein (Pal) of Escherichia coli (E. coli) is a characteristic bacterial lipoprotein, with an N-terminal lipid moiety anchoring it to the outer membrane. Previous studies of Pal place the lipoprotein in the periplasm of E. coli, allowing it to interact with peptidoglycan. We describe for the first time, a subpopulation of Pal which is present on the cell surface of E. coli. Flow cytometry and confocal microscopy detect anti-Pal antibodies on the surface of intact E. coli cells. Interestingly, Pal is surface exposed in an “all or nothing” manner suggesting that most cells contain only internal Pal.
Student Author: Juliana Shaw , Victoria MacPherson , David Barnard , John Bettinger , Brooke D'Arcy
The identification of novel targets for the discovery and or development of new antibiotics is a bottleneck in the scientific community. Here we identified a novel target by showing the identification of 5 compounds that inhibit the enzyme diaminopimelate aminotransferase (DapL) involved in the synthesis of bacterial cell wall and the proteogenic amino acid lysine. The work was facilitated through a high throughput inhibition screen using a compound library. Each inhibitor is derived from one of four classes with different central structural moieties: a hydrazide, a rhodanine, a barbiturate, or a thiobarbiturate. This study provides important information to expand our current understanding of the structure/activity relationship of DapL and putative inhibitors that are potentially useful for the design and or discovery of novel biocides. The study was collaboration between the Hudson lab at RIT, the Vederas lab at the University of Alberta, Canada, and The Dobson lab at the University of Canterbury, New Zealand. The work was funded by an NSF and a COS DRIG award to the Hudson Lab.
Student Author: Alexander Triassi, Matthew Wheatley
Physical and structural properties can influence the magnetic properties of a system, including hysteretic behavior. Shown here are the results of X-ray scattering performed on three of six Co/Pt multilayer thin films with perpendicular magnetic anisotropy grown at different sputtering pressures between 3 and 20 mTorr. Measurements of the crystallinity, from the bulk lattice peaks of the Pt, provide a useful metric for determining the structural ordering of the films. We have compared the results of our current efforts to results obtained from earlier x-ray reflectivity and microscopy, as well as the magnetic properties obtained from magnetometry and magnetic force microscopy measurements. Understanding the correlation between the crystallinity and the hysteretic behavior and magnetic properties for these samples may help improve designs for magnetic media and increase the storage capacity of hard disk drives.