Research Highlights 2012

Welcome to the RIT College of Science Research Highlights page. The goal of this page is to highlight some of the college's faculty-student research projects.

School of Physics and Astronomy

Investigation of the Structural Ordering in Magnetron Sputtered Co/Pt Films with Perpendicular Magnetic Anisotropy

Faculty Advisor(s):  Michael S. Pierce, School of Physics and Astronomy, Richard Hailstone, Center for Imaging Science is the one responsible for the TEM images shown in the figure.

Student Researcher: Junghune Nam, School of Physics and Astronomy

http://tigger.rit.edu

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.

Submitted December 6, 2012

School of Physics and Astronomy

Astronomical Research at the Kitt Peak National Observatory


Faculty Advisor: Michael Richmond, School of Physics and Astronomy,
                         LAMA (Laboratory for Multiwavelength Astrophysics)

Students:   Valerie Rapson (graduate Astrophysical Sciences and Technology)
                 Dave Principe (graduate Astrophysical Sciences and Technology)
                 Jack Wong (undergraduate Physics)

Links:  LAMA web page  http://lama.cis.rit.edu/
           more information on the WIYN 0.9m telescope

From November 8 to November 14, 2012, a team of researchers from RIT travelled to the Kitt Peak National Observatory in Arizona to use the WIYN 0.9-m telescope.  Led by Michael Richmond (Physics), the team included two graduate students in the AST program, Valerie Rapson and Dave Principe, and an undergraduate Physics major, Jack Wong.  The group observed a wide range of object, searching for faint planetary nebulae in binary star systems and transiting extrasolar planets, and measured several supernovae recently discovered by Japanese astronomers.

Submitted: December 6, 2012

School of Mathematical Sciences

Integrated Mathematical Models to Combat Dry Eye Syndrome

Faculty Advisors:  Kara Maki, CACM, SMS, David S. Ross, CACM, SMS

Student Researcher: Emily Holz, KGCOE, Biomedical Engineering

Center for Applied and Computational Mathematics

Link to this paper, which is based on Kara’s thesis.

Each time someone blinks, a thin multilayered film of fluid must reestablish itself, within a second or so, on the surface of the eye. This tear film plays a number of vital roles in maintaining the health and function of the eye. For example, the film provides an optical smooth surface for light to pass through for clear vision and it supplies nourishment and protection to the eye.   Any malfunction or deficiency of the tear film causes a collection of symptoms, including visual disturbance, discomfort, and potential damage to the ocular surface, recognized by ophthalmologists as dry eye syndrome. It is estimated that 5 million of Americans over the age of 50 have dry eye. The symptoms of this common condition hurt important activities of daily living such as reading and driving. Thus, new suggestions for treatment will benefit many people. There are approximately 35 million contact lens wearers in the United States and of these contact lens wearers 50% have reported experiencing dry eye symptoms, referred to as contact-lens-induced dry eye.  In this project we are developing a mathematical model of the mechanical interactions between a contact lens suspended in a tear film and the viscous liquid in which it is suspended.

Submission Date: Jun 5, 2012

School of Chemistry & Materials Science

Surface oxidation of single-walled carbon nanotube paper with oxygen atoms

Faculty Advisor: Gerald Takacs
Student Researchers: F. Lu*, J. Alvarenga*, B. Landi, R. Raffaelle, T. Debies and G.A. Takacs

*MS Materials Science and Engineering graduate students.

J. Adhesion Sci. Technol. (2012)DOI:10.1080/01694243.2012.705093

Submission date: August 27, 2012 

School of Chemistry & Materials Science


Surface Characterization of UV Photo-oxidized Colorless Polyimides

Faculty Advisor: Gerald Takacs
Student Researchers: A. Khot*, M. Razdan**, B. Parekh*, T. Debies

Incorporating  -C(CF3)2- groups into the backbone of the aromatic polyimides reduces the electronic interaction between chromophoric centers in the molecular structure which produces slightly colored to colorless films having optimal transparencies for space applications, such as thermal control coatings, low earth orbit (LEO) radiation exposure and solar sail propelled missions. Spacecraft in LEO are exposed to UV radiation and the presence of reactive oxygen-containing species, e.g., O and O3. This publication investigates the following two colorless polyimides (Attachment 1) exposed to UV photo-oxidation at atmospheric pressure.

 *MS Materials Science and Engineering graduate students.

** MS Chemistry graduate student.

Submission date: August 27, 2012

Thomas H. Gosnell School of Life Sciences

The genetic code supports the maintenance of DNA flexibility over evolutionary timescales

Katharina Schulze

Faculty Advisor: Gregory Babbitt
Student Researcher: Katharina Schulze

Despite nearly 50 years of familiarity with the genetic code, biologists still know little about why it is organized in the way it is. Recent research has suggested that the organization of the genetic code is highly non-random, but not exactly why. Using a combination of computer simulation and comparative genomics, Dr. Gregory Babbitt and BS/MS Bioinformatics student, Katharina Schulze, have demonstrated that the genetic code is extremely well optimized with respect to potential mutational effects on the flexibility of phosphate linkages in the DNA backbone. Therefore, the organization of the genetic code is not likely a random accident of evolution, as once assumed by the founders of molecular biology in the mid-twentieth century, but actually facilitates the multiplexing of both genetic and structurally-encoded regulatory information into the same molecular context.

Oxford Journals-Life Sciences-Genome Biology and Evolution

Submission date: August 23, 2012

School of Physics and Astronomy

Geometrically Cohesive Granular Materials

Faculty Advisor:  Scott Franklin, School of Physics and Astronomy

Student Researchers:  Andrew Loheac and Christian Richardsen, Physics

Links:  http://people.rit.edu/svfsps/Research/lab.html

Description:  Unlike ordinary granular materials (sand, rice, sugar, etc.), non-spherical grains such as staples can display a surprising ability to stick together. Physics majors Andrew Loheac and Christian Richardsen are working with Professor Scott Franklin to study the properties of these materials through computer simulations and novel experiments. One new finding is that long piles are much easier to pull apart than shorter piles, a surprising result that can be explained through a weakest link theory. Their work was recently featured as the cover article of Physical Review Letters (2012) and highlighted by American Physical Society on physics.aps.org.

Submission date: August 20, 2012

School of Physics and Astronomy

Not all lectures are equal!  Influence of subject on faculty practice

Faculty Advisor:  Scott Franklin, School of Physics and Astronomy, Science & Mathematics Education Research Collaborative

Student Research:  Tricia Chapman

Links:  http://www.rit.edu/cos/smerchttp://people.rit.edu/svfsps/Research/lab.html

Description: Physics faculty display a range of practices in reform-style workshop classrooms.  Recently published in the Proceedings of the Physics Education Research Conference, RIT physics major Tricia Chapman found that not only do faculty teaching electricity & magnetism lecture twice as often do faculty teaching mechanics, but they do so for a fundamentally different purpose.  E&M instructors primarily lecture before a student activity as a demonstration (what is called "Tell & Practice"), whereas mechanics instructors tend to lecture after an activity as a summative exercise (named "Invent & Tell"). We find many reasons for this difference, ranging from instructor philosophy to the nature of current materials, with important implications for future curricular development.

Submission date: August 20, 2012

School of Chemistry & Materials Science

Targeted Molecular Imaging Agents for Detection of Cancer and Heart Disease

Representation of a targeted multi-modal imaging agent, the targeting mechanism with diseased tissue and an example of a selective fluorescence of a grafted tumor in a mouse

Advisor: Hans Schmitthenner, Chemistry and Imaging Research Scientist, CIS and SCMS, College of Science

Student Researcher(s):  Taylor Barrett, Zane Barnstien, Chelsea Wiedman (Chemistry Majors)

www.rit.edu/cos/hans-schmitthener

For the early detection of cancer and heart disease there is a growing need for diverse targeted molecular imaging agents. The goal of our research program is to provide versatile, easy-to-use templates to construct these imaging agents as few facile methods are available today. The templates are chemical scaffolds comprised of peptides with differentially protected or “masked” side chains. This enables selective “unmasking” and binding different types imaging agents and targeting agents together on each template. The imaging agents we are focused on are contrast agents for magnetic resonance imaging (MRI), chelating agents for positron emission tomography (PET) and dyes for near infrared fluorescence (NIRF). The targeting agents are peptides which will enhance contrast in MRI or selectively illuminate diseased tissues. We have synthesized the protected templates, and are currently investigating the unmasking and binding to imaging and targeting agents.

 Submission date: August 16, 2012

Thomas H. Gosnell School of Life Sciences

Verrucomicrobium spinosum: A model system for Chlamydia?

The diagram depicts amino acids that are conserved in the active site of the aminotransferase enzyme from V. spinosum.

Faculty Advisor: Andre O. Hudson

Undergraduate Student Researchers: Victoria Nachar (Biology), Francisco Savka (Biology), Sean McGroty (Bioinformatics)

Lab page link: http://people.rit.edu/aohsbi/

The bacterium Verrucomicrobium spinosum is closely related to the bacterium that causes the STD Chlamydia (Chlamydia trachomatis). Using biochemical and genomic analysis, V. spinosum was found to employ the recently discovered aminotransferase pathway for diaminopimelate, lysine and cell wall biosynthesis by three undergraduate students in The Thomas H. Gosnell School of Life Sciences (Victoria Nachar, Biology) (Francisco Savka, Biology) and (Sean McGroty, Bioinformatics). Since animals, particularly humans do not possess the enzymatic machinery for diaminopimelate/lysine biosynthesis; this pathway is an attractive target for the development of antibiotics using V. spinosum as a model system.

Submission date: June 5, 2012

Chester F. Carlson Center for Imaging Science

Lidar Sensing of Complex Snow and Ice Surfaces

Faculty Advisor: John Kerekes, CIS, DIRS

Student Researchers: Jiashu Zhang, Ph.D. Student, Imaging Science, and Kimberly Horan, M.S. Student, Imaging Science

Digital Imaging and Remote Sensing Laboratory

Lidar (light detection and ranging) remote sensing has been found to be a useful method of monitoring the dynamics and mass balance of glaciers, ice caps, and ice sheets. However, it is also known that ice surfaces can have complex structure, which can challenge their accurate retrieval with lidar sensing. In support of future lidar sensing satellites, such as NASA's upcoming ICESat-2 mission, a joint research project is ongoing involving researchers in RIT's Center for Imaging Science and collaborators in the Department of Geology at the University at Buffalo. The general approach is to 1) define realistic complex ice surfaces, 2) render physics-based lidar image simulations, and 3) compare the resulting data to the known surfaces to gain insight into the phenomenology of lidar sensing of snow and ice. The figure shows an early result of the research as a simulation of a side view of surface and noise returns as measured by a GeigerMode Avalanche PhotoDiode detector. The thick line shows the returns from a simulated snow surface with deep crevasses while the point-like returns are noise returns seemingly coming from the atmosphere above or the snow pack below the surface. Collaborators are using this type of data to develop surface extraction algorithms with a goal of improving the accuracy of monitoring changes in the heights of glaciers due to global climate change.

 Submission date: May 2, 2012

School of Physics and Astronomy

Mapping gas flows around supermassive black holes in nearby galaxies

Faculty Advisor(s):  Andy Robinson & David Axon, Physics/AST, LAMA
Student Researcher:  Davide Lena, Astrophysical Sciences and Technology PhD program

Laboratory for Multiwavelength Astrophysics LAMA

Graduate Studies in Astrophysical Sciences and Technology

Supermassive black holes are the "engines" of Active Galactic Nuclei, whose light output often overwhelms that of the entire stellar population of the galaxy. The aim of this project is to understand the physical processes that drive gas flows between the active nucleus and the host galaxy, providing ''fuel'' for the black hole and transferring mechanical energy back to the galaxy. Our research is based on data from Integral Field Spectrographs mounted on the 8-m GEMINI telescopes in Hawaii and Chile. These instruments produce a spectrum at each pointin an image, allowing us to construct detailed maps of the gas motions in the centers of several nearby galaxies (see image). The project, which is funded by the National Science Foundation, is a collaboration with a team of Brazilian astronomers based at the Universidade Federal do Rio Grande do Sul.

Submission date: April 10, 2012


chester f. carlson center for Imaging Science

The Euclidean Commute Time Distance Transformation Applied to Spectral Remotely Sensed Images

 

Faculty Advisor: David Messinger, CIS, DIRS

Student Researcher: Jamie Albano, Ph.D. Candidate, Imaging Science

The Digital Imaging and Remote Sensing (DIRS) Laboratory

Spectral images are collected from airborne or satellite sensors in more colors than the traditional red, green, and blue. These images are then used for large scale material identification and characterization for applications such as environmental monitoring. Spectral image analysis problems often begin by applying a transformation that generates an alternative representation of the spectral data with the intention of exposing hidden features not discernable in the original space. Our research has developed a transformation based on a Markov-chain model of a random walk on a graph and we have shown how application to spectral image clustering improves results over traditional processing schemes. Results are shown for a standard clustering algorithm applied to a hyperspectral image after application of the Commute Time Distance transformation. Top image is the input data with training data highlighted; bottom image is the resulting class map. This work was presented at the Department of Energy Conference on Data Analysis in March 2012 where it was awarded "Best Student Poster."

Submission date: April 1, 2012

Use of Hyperspectral Imagery to Support Archeological Land Use Studies in Oaxaca, Mexico

Apr1

 

Faculty Advisors: David Messinger, Center for Imaging Science, Bill Middleton, Sociology & Anthropology (COLA)

Student Researcher: Kelly Canham, Ph.D. candidate in Imaging Science

Read More>>>

The goal of this research is to produce land-use maps for aiding archaeologists studying the Zapotec civilization. Fractional abundance maps have been produced from Hyperion hyperspectral data over Oaxaca, Mexico, by applying a new spatially adaptive spectral unmixing algorithm. However, to correlate the fractional abundance maps generated from the HSI image processing, a relationship between the known materials located in Oaxaca, Mexico, and the spectral profiles of these materials must be established. A campaign during December 2011, (the dry season in Oaxaca) took place for the explicit task of obtaining spectral profiles of the most common materials found in the region. Ground-truth information was collected for three Oaxaca valleys (Tlacolula, Yanhuitlan, and Ycuitla). Common materials and associated regions were recorded and material samples were collected at many of these locations. Aspects of this research project have won international competitions for the spatially adaptive spectral processing algorithms and the use of a field spectrometer for this field work.

Submission date: April 1, 2012

school of Mathematical Sciences

Searches for Gravitational Waves


GW animation

http://ccrg.rit.edu/research/gravitational-waves

Faculty advisor: John Whelan (SMS and CCRG)

Student Researchers: Prabath Peiris (AST), Anthony Castiglia (SMS), Benjamin Farr (Physics '09) Postdoc: Melissa Frei (SMS)

Gravitational waves (GWs) are distortions in the fabric of space and time, predicted by Einstein's General Theory of Relativity, which travel at the speed of light. They are generated by rapid movements of massive objects, such as black holes and/or neutron stars in close binary orbits, supernova explosions, rapidly spinning deformed neutron stars, and the extreme conditions in the early universe shortly after the Big Bang. While the effects of GWs have been observed, the waves themselves have not yet been detected. An international network of detectors has recently been constructed which is expected to make the first detection of gravitational waves and allow us to observe the universe with gravitons as well as photons. This network includes the Laser Interferometer Gravitational-Wave Observatory (LIGO), which uses an L-shaped interferometer to measure changes smaller than a proton in the difference between the 2.5-mile lengths of its "arms". RIT researchers work within the LIGO Scientific Collaboration to analyze the data taken by LIGO and other detectors, searching for the signatures of astrophysical systems such as accreting neutron stars and binaries of spinning black holes.The image shows the effects of the gravitational waves generated by a simple system, a binary of two equal masses in a circular orbit around their center of mass. (Upper left; the circular orbit looks elliptical because we are viewing it at a 75-degree angle.) The changes between distances of freely floating objects (lower left) can be resolved into two polarization states, known as "plus" (shown in green) and "cross" (shown in red). The signal in a detector like LIGO will be a combination of these plus and cross waveforms, plus instrumental noise. In a physical system, the gravitational waves will carry away energy, causing the binary orbit to decay and the masses to spiral in towards each other, emitting a "chirp"-like waveform.

Submission date: March 23, 2012

School of Physics and Astronomy

Searching for exoplanets in M103

Faculty Advisor: Michael Richmond, Physics, LAMA

Student Researchers: Valerie Rapson, Billy Vazquez, graduate students in Astrophysical Sciences and Technology

Over the past decade, many planets have been discovered circling other stars. Graduate students Valerie Rapson and Billy Vazquez have been studying a cluster of stars (see picture) using a small telescope in Rochester, looking for brief dips in the brightness of an individual star when a planet passes in front of it. To confirm their candidates, they will be using a big telescope: the WIYN 0.9-m telescope at Kitt Peak National Observatory (see picture). RIT is a member of the WIYN 0.9m consortium and sends several students each year to Kitt Peak.

Submission date: March 21,2012

School of Mathematical Sciences

Study of multi black hole and ring singularity apparent horizons

Faculty advisor: Carlos O. Lousto (SMS, CCRG)

Student Researchers: Gabriela Jaramillo (SMS, MS applied mathematics)

Links: http://ccrg.rit.edu/       Published in Phys.Rev. D84 (2011) 104011.

We study critical black-hole separations for the formation of a common apparent horizon in systems of N black holes in a time-symmetric configuration. We study in detail the aligned equal mass cases for N=2, 3, 4, 5, 6, and relate them to the unequal mass binary black-hole case. We then study the apparent horizon of the time-symmetric initial geometry of a ring singularity of different radii. The apparent horizon is used as indicative of the location of the event horizon in an effort to predict a critical ring radius that would generate an event horizon of toroidal topology. We found that a good estimate for this ring critical radius is 20/(3)M. We briefly discuss the connection of this two cases through a discrete black-hole necklace configuration.

 

Submission date: March 20, 2012

Thomas H. Gosnell School of Life Sciences

Another reason students struggle: Overestimation by Biology faculty and textbooks of students' prior knowledge

Mentors: Dina L Newman and L. Kate Wright, School of Life Sciences, Science & Mathematics Education Research Collaborative (SMERC)

Student Researcher: Christina Catavero

Successful teaching requires faculty be aware of their students' prior knowledge of a subject. Meiosis, a special type of cell division that creates sperm or ova, is an important topic in both genetics and evolution, yet one in which students routinely struggle. Interviews of RIT students have produced new insight into students thoughts and confusion, and shed new light on why they struggle. Foundational concepts such as chromosome structure, homology and ploidy are common stumbling blocks, and confusion on these topics persists even after multiple exposures to instruction. It appears that instructors do not fully appreciate the knowledge state of the entering student. We surveyed faculty who teach the subject about what they believe students should know at each level of their biology education and found that at every level they make incorrect assumptions about student prior knowledge. Similarly, textbooks typically leave out discussion of these concepts, especially in the context of cell division. The figure shows that, for four fundamental concepts, 40%-60% of faculty and textbooks assume student understanding (blue and green lines) while fewer than 10% of students can actually demonstrate proficiency. Since students never learn the basics, few ever progress further to truly comprehending meiosis, and by extension genetics and evolution. This project has the potential to enhance biology education across the country by educating the authors of standards as well as the teachers about the disconnection between high school and college expectations.

Submission date: March 20, 2012

Chester F. Carlson Center for Imaging Science

An Switchable fMRI Phantom Based on the Alignment of Molecular Dipoles

Faculty Advisor:Joseph Hornak, CIS, Magnetic Resonance Laboratory

Student Researcher: Yujie Qiu

Link: Magnetic Resonance Laboratory

Functional magnetic resonance imaging (fMRI) is a magnetic resonance imaging (MRI) technique used to map the thought and motor control regions of the human brain. The technique is based on detection of rapid and subtle changes in the MRI signal as a result of brain activity. There is a need for fMRI phantoms or standards that mimic this change as rapidly as is seen in the brain. We are exploring one method based on the alignment of the dipole moments of polar molecules with the application of an electric field. The method is fast and produces a controllable change in the MRI signal comparable to that seen in the human brain.

Submission date: March 20, 2012

School of Physics and Astronomy

Learning, retention, and forgetting of Newton's third law throughout university physics

Authors (RIT undergrads have *): Eleanor C. Sayre, Scott V. Franklin, Stephanie Dymek*, Jessica Clark*, Yifei Sun

Accepted to: Physical Review Special Topics - Physics Education Research  Online

We present data from a between-student study on student response to questions on Newton's Third Law given in two introductory calculus-based physics classes (Mechanics and Electromagnetism) at a large northeastern university. Construction of a response curve reveals subtle dynamics in student learning not capturable by pre/post testing. We find a signicant positive efect of instruction that diminishes by the end of the quarter. Two quarters later, a signicant dip in correct response occurs when instruction changes from the vector quantities of electric forces and elds to the scalar quantity of electric potential. When instruction returns to vector topics, performance rebounds to initial values.

Submission date: March 20, 2012

School of Mathematical Sciences

Computational Relativity and Gravitation

Faculty Advisers: Hans-Peter Bischof, Manuela Campanelli, Joshua Faber, Carlos Lousto, John Whelan, Yosef Zlochower

Postdocs: Melissa Frei, Bruno Mundim, Hiroyuki Nakano, Scott Noble, Jason Nordhaus

Student Researchers: Anothony Castiglia, Benjamin Farr, Billy Vazquez, David Di Lernia, Gabriela Jaramillo, Ian Ruchlin, Jeremy Berke, Lous Gallouin, Luke Coy, Marcelo Ponce, Nicholas Battista, Prabath Peiris

Link: Center for Computational Relativity and Gravitation

Gravity is associated with some of the most spectacular events in our universe. When two black holes collide, for a brief time, they become the most "luminous" objects in the observable universe. The amount of energy released from supermassive black hole collisions is staggering, the equivalent of converting 100 million suns into pure energy. Black holes can also rip apart neutron stars, converting part of the mass of the neutron star into a burst of energy known as a gamma ray burst. Massive stars end their lives in a spectacular supernova explosion powered by gravity. The figures shows a 1 solar mass black hole merging with a 100 solar mass black hole, the magnetized accretion disk around a merging binary, and a star undergoing a supernova explosion.

Submission date: March 20, 2012

School of MATHEMATICAL Sciences

Cardiac Electrophysiology

Faculty Advisor: Elizabeth Cherry, Center for Applied and Computational Mathematics

Student Researchers: Michael Bell (recent math MS grad who has applied to PhD programs for the fall), Alexander Bogart (software engineering), Colden Cullen (interactive games and media), Mohamed Elshrif (GCCIS PhD program), Raphael Kahler (computational math), Benjamin Liu (applied math), Peter Muller (computer engineering), Ryan McLaughlin (computer engineering), Steven Kroh (software engineering)

Link: acm.rit.edu/research/cardiac.php

We study the propagation of electrical waves in the heart. These waves, which arise naturally about once every second, signal the heart to contract in a coordinated manner to pump blood throughout the body. Disruptions to normal wave propagation can occur in the context of cardiac disease or other factors and can give rise to either short-lived or persistent arrhythmias that may compromise the heart's pumping function. Many of these arrhythmias are characterized by the presence of one or more spiral waves that rotate faster than the heart's intrinsic pacemaker. We aim to understand the mechanisms of initiation, maintenance, and termination of these arrhythmias by integrating mathematical modeling and simulation with both traditional experiments and theoretical analysis. Our work has encompassed the development of robust mathematical models of cardiac electrical dynamics; the creation of efficient numerical algorithms for solving the equations describing wave propagation using computer simulations; analysis of the nonlinear dynamics of cardiac tissue; and the application of modeling and simulation to analyze specific physiological problems, such as identifying physiological mechanisms underlying particular arrhythmias and low-energy defibrillation. Along with mathematics, our studies draw from a number of disciplines, including biology and physiology, computer science, biological physics, imaging science, nonlinear dynamics, and complex systems.

Submission date: March 20, 2012 

School of Physics and Astronomy

Relativistic Stellar Dynamics

Faculty: David Merritt, Dept. of Physics and CCRG 

Student Researchers: Fabio Antonini (AST) Postdocs: Eugene Vasiliev, Alessia Gualandris (Physics, CCRG)
 URL: http://en.wikipedia.org/wiki/GravitySimulator


The centers of galaxies contain supermassive black holes (SMBHs), as well as dense clusters of stellar remnants: neutron stars and stellar-mass black holes, the end-states of the evolution of massive stars.  The interactions of the remnants with each other, and with the SBH, are believed to drive a number of important processes, including capture of stellar BHs by SMBHs, a process that could be observed via its generation of gravitational waves. Using a new computational approach, my group has achieved the first direct simulations of such systems over long (Myr) time scales.

This figure shows how the motion of stars very near to a supermassive black hole (SMBH) is affected by their self-interactions, and by general relativity. Each frame plots the evolution of the orbital planes of eight stars as they orbit about the Milky Way SMBH, for an elapsed time of two million years. The SMBH is rotating, which causes the orbital planes to precess; this is called "frame dragging" and appears in the plots as circular motion. When the masses of the stars are increased, their self-interactions cause the motion to deviate from the smooth precession induced by frame dragging.
(Credit: D. Merritt et al., Physical Review D, vol. 81, id. 062002, 2011).

Submission date: January 18, 2012

 

 School of Chemistry and Materials Sciences

Surface Modification of Multi-walled Carbon Nanotubes with Gaseous Oxygen and Chlorine Atoms

 Microwave Discharge of Ar/Oxygen Mixture

Student Researcher: Luciana Oliveira, MS Chemistry Graduate, Currently Ph.D. student at Clemson U.

Faculty Advisor:  Gerald A. Takacs, Professor of Chemistry, Department of Chemistry,Center for Materials Science & Engineering

Multi-walled carbon nanotube (MWNT) paper was surface modified with gaseous oxygen and chlorine atoms, and analyzed by X-ray photoelectron spectroscopy (XPS). The oxygen atoms were produced by a low-pressure microwave (MW) plasma discharge of an Ar-O2 mixture and the results were compared to a previous study using VUV photo-oxidation. The presence of VUV (λ= 104.8 and 106.7 nm) radiation showed higher levels of oxidation (ca. 7.4 at% O) than the MW results (ca. 6.3 at %) which were conducted in the absence of radiation from the plasma. Oxygen atoms reacted with the -conjugation of the MWNTs to primarily produce the ether/epoxide groups. Chlorine atoms, which were generated by UV photolysis of Cl2, readily reacted with the nanotubes to yield saturation levels of ca. 13 at% Cl.
Accepted for publication in Journal of Adhesion Science and Technology (2012).

Submission date: January 12, 2012

 

Thomas H. Gosnell School of Life Sciences

Bacterial diseases disrupted by natural products from the beehive

Student Researcher: Zackery Bulman, Biotechnology Graduate, 2011. 
Currently in the PharmD Program at University at Buffalo School of Pharmacy and Pharmaceutical Sciences, Buffalo, NY

Faculty Advisor: Mike Savka, School of Life Sciences Laboratory A355 Gosnell Hall

Read More:
http://www.ncbi.nlm.nih.gov/pubmed?term=Savka%20MA

 

Recent Publication: Zackery Bulman, Phuong Le, André O. Hudson and Michael A. Savka. A novel property of propolis (bee glue): anti-pathogenic activity by inhibition of N-acyl-homoserine lactone mediated signaling in bacteria. Journal of Ethnopharmacology. 138 (2011) 788-797. doi:10.1016/j/jep2011.10.029


http://www.sciencedirect.com/science/article/pii/S0378874111007689

 

A complementary or alternative approach to antibiotic agents to control bacterial diseases is the identification and development of anti-pathogenic control agents. Such anti-pathogenic agents could target a gene regulatory system known as quorum sensing (QS). In the above publication, we show that the natural product from the beehive called propolis or bee glue disrupts quorum-sensing systems. In this regard, anti-pathogenic compounds from bee harvested propolis could be identified and isolated and thus will be valuable for the further development of anti-pathogenic therapeutics to disrupt QS signaling systems which regulate the disease causing factors in many pathogenic bacteria.

Submission date: January 12, 2012

 

School of Chemistry and Materials Sciences

Using structural analysis and biochemical techniques to study protein vaccine candidates 

 

Faculty Advisors: Lea Vacca Michel (RIT, Department of Chemistry)

Collaborators:
Dr. Michael Pichichero (RGHS, Research Institute), Dr. Leslie Kate Wright (RIT, School of Life Sciences)                                                            

Student Researchers: Anthony Mangan (MS student, Chemistry),Kyle Grimaldi (5th year, Chemistry),Melody Frink (4th year, Biochemistry),Breanna Kalmeta (3rd year, Biochemistry),Joy Snyder (3rd year, Biochemistry),Rachel Schmidt (3rd year, Biochemistry),Bethany Novick (2nd year, Biochemistry),John Bettinger (2nd year, Biochemistry)

Link: http://www.rit.edu/cos/chemistry/Michel.html    

Nontypable Haemophilus influenzae (NTHi) causes otitis media (ear infection), sinusitis, and acute exacerbations of chronic bronchitis. The outer membrane lipoprotein P6, discovered 30 years ago, is currently one of the leading protein vaccine candidates for NTHi. Although P6 has been studied for its immunological properties, not much is known about its structural orientation or localization in NTHi. Therefore, we used structural and biochemical techniques to elucidate the orientation of P6 in the outer membrane of NTHi, with surprising results (Vaccine 2011, 29: 1624-1627). Currently, we are finishing work on P6 and are starting the characterization of other protein vaccine candidates. 

Submission Date: January 10, 2012

 Thomas H. Gosnell School of Life Sciences

Role of the Pyrroline5-Carboxylate Synthetase gene

Radji and Newman
 
Faculty Advisor: Dina Newman,  School of Life Sciences
 
Student Researcher: Mohammed Andres Mostajo Radji, Biotechnology - Bioinformatics Student
 
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Presbycusis, or age-related hearing loss, is a common hearing disorder that affects much of the elderly population, particularly men.  Several environmental factors are associated with this type of hearing loss. However, only a few genetic factors have been found to be correlated with the phenotypes and severity of this syndrome. Variations in the expression of the Pyrroline 5-Carboxylate Synthase (PYCS) gene appear to be associated with the early onset of Presbycusis. PYCS encodes an enzyme that breaks down glutamate to synthesize proline and ornithine.  Since glutamate is the key neurotransmitter in the  auditory system, subtle differences in regulation of PYCS could be important to hearing.  Recent work has provided evidence of gender-specific genetic regulation of the PYCS gene and its significance in age-related hearing-loss.

 

Submission Date: June 13, 2011

 

Chester F. Carlson Center for Imaging Science

Perception of Colorfulness for Display Design

HaoResearchImage
 
Faculty Advisor: Mark Fairchild, Center for Imaging Science, Munsell Color Science Laboratory
 
Student Researcher: Hao Li, Color Science M.S. Program
 
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Generally the perceived colorfulness scenes increases with light level (luminance). We are examining the relationship between the luminance and saturation of the primaries for advanced image displays with respect to the perception of overall display colorfulness. Initial results indicate that reduction in primary color saturation cannot be overcome by increased luminance when display primaries are viewed in isolation. However, the opposite result is found for complex images. Understanding such perceptual effects will aid the development of future high-dynamic-range displays while considering energy conservation. These results will be presented at the upcoming IS&T/SID Color Imaging Conference. (June, 2011)
 
Submission Date: June 23, 2011