Physical Sciences and Mathematics Commons^™

Structured Illumination Diffuse Optical Tomography For Mouse Brain Imaging, Matthew Reisman

Arts & Sciences Graduate Student Theses and Dissertations

As advances in functional magnetic resonance imaging (fMRI) have transformed the study of human brain function, they have also widened the divide between standard research techniques used in humans and those used in mice, where high quality images are difficult to obtain using fMRI given the small volume of the mouse brain. Optical imaging techniques have been developed to study mouse brain networks, which are highly valuable given the ability to study brain disease treatments or development in a controlled environment. A planar imaging technique known as optical intrinsic signal (OIS) imaging has been a powerful tool for capturing functional …

Fast Monte Carlo Simulations For Quality Assurance In Radiation Therapy, Yuhe Wang

Arts & Sciences Graduate Student Theses and Dissertations

Monte Carlo (MC) simulation is generally considered to be the most accurate method for dose calculation in radiation therapy. However, it suffers from the low simulation efficiency (hours to days) and complex configuration, which impede its applications in clinical studies. The recent rise of MRI-guided radiation platform (e.g. ViewRay’s MRIdian system) brings urgent need of fast MC algorithms because the introduced strong magnetic field may cause big errors to other algorithms. My dissertation focuses on resolving the conflict between accuracy and efficiency of MC simulations through 4 different approaches: (1) GPU parallel computation, (2) Transport mechanism simplification, (3) Variance reduction, …

Investigation Of Neonatal Pulmonary Structure And Function Via Proton And Hyperpolarized Gas Magnetic Resonance Imaging, Nara Savoye Higano

Arts & Sciences Graduate Student Theses and Dissertations

Magnetic resonance imaging (MRI) is a modality that utilizes the phenomenon of nuclear magnetic resonance (NMR) to yield tomographic images of the body. Proton (1H) MRI has historically been successful in soft tissues but has suffered in the lung due to a variety of technical challenges, such as the low proton-density, rapid T2* relaxation time of the lung parenchymal tissue, and inherent physiological motion in the chest. Recent developments in radial ultrashort echo time (UTE) MRI have in part overcome these issues. In addition, there has been much progress in techniques for hyperpolarization of noble gases (3He and 129Xe) out …

The Chemistry And Biology Of Iron-Scavenging Natural Products From Pathogenic Acinetobacter Baumannii, Justin Shapiro

Arts & Sciences Graduate Student Theses and Dissertations

Multidrug resistant (MDR) Gram-negative bacteria represent a global health crisis. Traditional antibiotics create selective pressure and breed resistance, making our current drugs less and less effective. Targeting of bacterial virulence factors has gained interest as an alternative strategy to potentially circumvent this problem. Virulent Acinetobacter baumannii synthesize and secrete pre-acinetobactin, a small molecule metal chelator that scavenges life-sustaining iron and is critical for establishing infection. The work described herein sheds light on the unusual properties of a non-enzymatic isomerization from pre-acinetobactin to acinetobactin and proposes a siderophore-swapping mechanism by which A. baumannii expands its pH window for virulence. Knowledge from …

Synthesis, Characterization, And Spectroscopy Of Donor-Acceptor Charge Transfer Complexes, Dominic Kofi Kersi

Chemistry and Chemical Biology ETDs

A series of square-planar metal (diimine)(dichalcogenolene) chromophoric complexes have been synthesized, characterized and studied spectroscopically. Studies conducted on diimineplatinum(II) dichalcogenolene complexes (LPtL’) using time resolved spectroscopic techniques such as transient absorption and emission, reveal a charge-separated excited state of the type dichalcogenolene → diimine charge-transfer (LL’CT) [(dichalcogenolene^•+)Pt(diimine^•-) with an open shell donor-acceptor biradical character. This makes the low-energy ligand-to-ligand charge-transfer (LL’CT), or the mixed-metal ligand-to-ligand charge-transfer (MMLL’CT), transitions of diimineplatinum(II) dichalcogenolene complexes particularly interesting to us in facilitating our knowledge of biradical charge-separated states. Long-live excited state lifetimes were observed for these complexes upon visible photoexcitation …

First Narrow-Band Search For Continuous Gravitational Waves From Known Pulsars In Advanced Detector Data, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars …

First Low-Frequency Einstein@Home All-Sky Search For Continuous Gravitational Waves In Advanced Ligo Data, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, Teviet Creighton, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov

Physics & Astronomy Faculty Publications

We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7 …

Erosion In Extruder Flows: Analytical And Numerical Study, Miron Kaufman, Petru S. Fodor

Physics Faculty Publications

© 2017 Author(s). We consider the erosion of particles (e.g. carbonblack agglomerates) advected by the polymeric flow in a single screw extruder. We assume a particle to be made of primary fragments bound together. In the erosion process a primary fragment breaks out of a given particle. Particles disperse because of the shear stresses imparted by the fluid. The time evolution of the numbers of particles of different sizes is described by the Bateman coupled differential equations developed a century ago to model radioactivity. Using the particle size distribution we compute an entropic fragmentation index which varies from 0 for …

Observation Of Top Quark Production In Proton-Nucleus Collisions, A. M. Sirunyan, The Cms Collaboration, M. M. Baarmand, Vallary Bhopatkar, S. Colafranceschi, M. Hohlmann, D. Noonan, T. Roy, F. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of psNN 8.16 TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 nb−1. The significance of the t¯t signal against the background-only hypothesis is above 5 standard deviations. The measured cross section is σ ¯ 45 8 nb, consistent with predictions from perturbative quantum chromodynamics.

A Statistical Study Of Student Success In The Bgsu Honors College, Sarah Hercules

Honors Projects

Higher education has long tried to find the best measures to predict student success. Different colleges often have different guidelines, requiring different criteria to be evaluated. The BGSU Honors College has struggled with retention and recruitment of underrepresented students with their current admission criteria. This analysis studies different measures of student success such as BGSU GPA and number of completed Honors credits for high-achieving BGSU students who enrolled from Fall 2013 through Fall 2016 to find the best predictors of student success through regression analysis. Throughout this paper, the impact of ethnicity, gender, the college of a student’s program, high …

Similar Ultrafast Dynamics Of Several Dissimilar Dirac And Weyl Semimetals, Christopher P. Weber, Bryan S. Berggren, Madison G. Masten, Thomas C. Ogloza, Skylar Deckoff-Jones, Julien Madéo, Michael K. L. Man, Keshav M. Dani, Lingxiao Zhao, Genfu Chen, Jinyu Liu, Zhiqiang Mao, Leslie M. Schoop, Bettina V. Lotsch, Stuart S. P. Parkin, Mazhar Ali

Physics

Recent years have seen the rapid discovery of solids whose low-energy electrons have a massless, linear dispersion, such as Weyl, line-node, and Dirac semimetals. The remarkable optical properties predicted in these materials show their versatile potential for optoelectronic uses. However, little is known of their response in the picoseconds after absorbing a photon. Here, we measure the ultrafast dynamics of four materials that share non-trivial band structure topology but that differ chemically, structurally, and in their low-energy band structures: ZrSiS, which hosts a Dirac line node and Dirac points; TaAs and NbP, which are Weyl semimetals; and Sr_{1–y …}

Hodge Theory On Transversely Symplectic Foliations, Yi Lin

Mathematical Sciences: Faculty Publications

In this paper, we develop symplectic Hodge theory on transversely symplectic foliations. In particular, we establish the symplectic dδ-lemma for any such foliations with the (transverse) s-Lefschetz property. As transversely symplectic foliations include many geometric structures, such as contact manifolds, co-symplectic manifolds, symplectic orbifolds, and symplectic quasi-folds as special examples, our work provides a unifying treatment of symplectic Hodge theory in these geometries.

As an application, we show that on compact K-contact manifolds, the s-Lefschetz property implies a general result on the vanishing of cup products, and that the cup length of a 2n+1 dimensional compact K-contact manifold with the …

Effect Of Counter Ions On The Self-Assembly Of Polystyrene-Polyphosphonium Block Copolymers, Benjamin Hisey, Jasmine V. Buddingh, Elizabeth R. Gillies, Paul J. Ragogna

Chemistry Publications

The ability to manipulate block copolymers on the nanoscale has led to many scientific and technological advances. These include nano-scale ordered bulk and thin films and also solution phase components, these are promising materials for making smaller ordered electronics, selective membranes, and also biomedical applications. The ability to manipulate block copolymer material architectures on such small scales has risen from thorough investigations into the properties that affect the architectures. Polyelectrolytes are an important class of polymers that are used to make amphiphilic block copolymers. In this context the authors synthesized polystyrene-b-polyphosphonium block copolymers with different anions coordinated to …

Translating Statistical Species-Habitat Models To Interactive Decision Support Tools, Lyndsie S. Wszola, Victoria L. Simonsen, Erica F. Stuber, Caitlyn R. Gillespie, Lindsey N. Messinger, Karie L. Decker, Jeffrey J. Lusk, Christopher F. Jorgensen, Andrew A. Bishop, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Understanding species-habitat relationships is vital to successful conservation, but the tools used to communicate species-habitat relationships are often poorly suited to the information needs of conservation practitioners. Here we present a novel method for translating a statistical species-habitat model, a regression analysis relating ring-necked pheasant abundance to landcover, into an interactive online tool. The Pheasant Habitat Simulator combines the analytical power of the R programming environment with the user-friendly Shiny web interface to create an online platform in which wildlife professionals can explore the effects of variation in local landcover on relative pheasant habitat suitability within spatial scales relevant to …

Sdss-Iv Manga: Probing The Kinematic Morphology–Density Relation Of Early-Type Galaxies With Manga, J. E. Greene, A. Leauthaud, E. Emsellem, D. Goddard, J. Ge, B. H. Andrews, J. Brinkman, J. R. Brownstein, J. Greco, D. Law, Y. -T. Lin, K. L. Masters, M. Merrifield, S. More, N. Okabe, D. P. Schneider, D. Thomas, D. A. Wake, Renbin Yan, N. Drory

Physics and Astronomy Faculty Publications

The "kinematic" morphology–density relation for early-type galaxies posits that those galaxies with low angular momentum are preferentially found in the highest-density regions of the universe. We use a large sample of galaxy groups with halo masses 10^12.5 < M_halo < 10^14.5 h^-1 M_⊙ observed with the Mapping Nearby Galaxies at APO (MaNGA) survey to examine whether there is a correlation between local environment and rotational support that is independent of stellar mass. We find no compelling evidence for a relationship between the angular momentum content of early-type galaxies and either local overdensity or radial position within the group …

Real-Time Indoor Assistive Localization With Mobile Omnidirectional Vision And Cloud Gpu Acceleration, Feng Hu, Zhigang Zhu, Jeury Mejia, Hao Tang

Publications and Research

In this paper we propose a real-time assistive localization approach to help blind and visually impaired people in navigating an indoor environment. The system consists of a mobile vision front end with a portable panoramic lens mounted on a smart phone, and a remote image feature-based database of the scene on a GPU-enabled server. Compact and elective omnidirectional image features are extracted and represented in the smart phone front end, and then transmitted to the server in the cloud. These features of a short video clip are used to search the database of the indoor environment via image-based indexing to …

Layer-By-Layer Assembled Membranes With Immobilized Porins, Sebastián Hernández, Cassandra Porter, Xinyi Zhang, Yinan Wei, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

New and advanced opportunities are arising for the synthesis and functionalization of membranes with selective separation, reactivity, and stimuli-responsive behavior. One such advancement is the integration of bio-based channels in membrane technologies. By a layer-by-layer (LbL) assembly of polyelectrolytes, outer membrane protein F trimers (OmpF) or “porins” from Escherichia coli with central pores ∼2 nm in diameter at their opening and ∼0.7 × 1.1 nm at their constricted region are immobilized within the pores of poly(vinylidene fluoride) microfiltration membranes, in contrast to traditional ruptured lipid bilayer or vesicle processes. These OmpF-membranes demonstrate selective rejection of non-charged organics over ionic solutes, …

Characterizations Of Some Classes Of Graphs That Are Nearly Series-Parallel, Victoria Fontaine

LSU Doctoral Dissertations

A series-parallel graph can be built from a single-edge graph by a sequence of series and parallel extensions. The class of such graphs coincides with the class of graphs that do not have the complete graph K₄ as a minor. This dissertation considers a class M₁ of graphs that are close to being series-parallel. In particular, every member of the class has the property that one can obtain a series-parallel graph by adding a new edge and contracting it out, or by splitting a vertex into two vertices whose neighbor sets partition the neighbor set of the original …

The Ability Of Different Imputation Methods To Preserve The Significant Genes And Pathways In Cancer, Rosa Aghdam, Taban Baghfalaki, Pegah Khosravi, Elnaz Saberi Ansari

Publications and Research

Deciphering important genes and pathways from incomplete gene expression data could facilitate a better understanding of cancer. Different imputation methods can be applied to estimate the missing values. In our study, we evaluated various imputation methods for their performance in preserving significant genes and pathways. In the first step, 5% genes are considered in random for two types of ignorable and non-ignorable missingness mechanisms with various missing rates. Next, 10 well-known imputation methods were applied to the complete datasets. The significance analysis of microarrays (SAM) method was applied to detect the significant genes in rectal and lung cancers to showcase …

Exploiting Synchrotron “Light” To Study Chemistry Of Trace Elements In Soils And Plants, Ryan Tappero

Sustainability Seminar Series

Biogeochemical studies often require characterization of elemental abundances and speciation in samples that are chemically and physically heterogeneous at the micrometer scale. Synchrotron radiation sources are ideal for developing high intensity, highly-focused X-ray probes for interrogating the speciation, transport, and reactions of trace elements in heterogeneous earth and biological materials with detection sensitivities in the attogram range and spatial resolutions less than 1 micrometer.

X-ray Fluorescence Microprobe (XFM) is a new, multi-modal X-ray fluorescence microscope recently installed at the National Synchrotron Light Source-II (NSLS-II) at Brookhaven National Laboratory. XFM has capabilities for X- ray micro-fluorescence (μ-XRF) imaging and tomography, X-ray …

Phosphate Speleothems In Caves Developed In Iron Ores And Laterites Of The Carajás Mineral Province (Brazil) And A New Occurrence Of Spheniscidite, Alan R.L. Albuquerque, Rômulo S. Angélica, Daniele F. Gonçalves, Simone P.A. Paz

International Journal of Speleology

The Carajás Mineral Province has one of the largest concentrations of caves in Brazil, and its iron ore is among the country’s main exports. As a result of iron ore intense extraction, new environmental policies have been implemented. In an attempt to balance economic activity and environmental conservation, an inventory and a relevance-based classification of caves were implemented in 2008 as criteria for environmental licensing of mining ventures. This implementation motivated the present study of phosphate speleothems in Carajás’ caves developed in ferriferous rocks. The objectives of this study are to describe the phosphate minerals and their formation processes based …

Evaluation Of Cadmium Bioaccumulaiton Of Periphyton And Aquatic Invertebrates Within Tributaries Of The Buffalo National River, Jacob Rollins Mccauley

Student Theses and Dissertations

The Rush Mining District, located along the Buffalo River in Arkansas, has a significant history of metal-mining operations. The tails and spoils of these operations deposit heavy amounts of raw ore into streams, including the deposition of cadmium, a minor constituent. Periphyton and invertebrate samples from two creeks within the Rush Mining District were measured for cadmium. Additionally, two creeks with no history of mining were sampled. Periphyton samples from mining sites had significantly higher concentrations of cadmium than samples collected at control sites. Invertebrate samples were classified into trophic levels before analysis. Invertebrate samples collected at treatment sites only …

Genetic Structure And Diversity Of Southern Disjunct Populations Of Etheostoma Caeruleum And Chrosomus Erythrogaster, Kyle James Dineen

Student Theses and Dissertations

Etheostoma caeruleum and Chrosomus erythrogaster are widespread with overlapping distributions that show comparable patterns of naturally disjunct populations on their range margins. Both species have populations on Crowley’s Ridge, AR and the Bluff Hills, MS, relatively recent geological formations. Microsatellite DNA loci were examined for both fish species to evaluate genetic diversity and connectivity among populations on Crowley’s Ridge, the Bluff Hills, and larger core populations. Genetic structuring was found between all populations of both species with lower genetic diversity found in populations of both species on Crowley’s Ridge. Results from this study suggest that both target species colonized these …

Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov

Michigan Tech Publications, Part 1

Tryptophan 7-halogenase catalyzes chlorination of free tryptophan to 7-chlorotryptophan, which is the first step in the antibiotic pyrrolnitrin biosynthesis. Many biologically and pharmaceutically active natural products contain chlorine and thus, an understanding of the mechanism of its introduction into organic molecules is important. Whilst enzyme-catalyzed chlorination is accomplished with ease, it remains a difficult task for the chemists. Therefore, utilizing enzymes in the synthesis of chlorinated organic compounds is important, and providing atomistic mechanistic insights about the reaction mechanism of tryptophan 7-halogenase is vital and timely. In this work, we examined a mechanism for the reaction of tryptophan chlorination, performed …

Unravelling The Correlation Of Electronic Structure And Carrier Dynamics In Cuins2 Nanoparticles, Wenhui Hu, John Ludwig, Brian Pattengale, Sizhuo Yang, Cunming Liu, Xiaobing Zuo, Xiaoyi Zhang, Jier Huang

Chemistry Faculty Research and Publications

In this work, we report the direct correlation of photoinduced carrier dynamics and electronic structure of CuInS₂ (CIS) nanoparticles (NPs) using the combination of multiple spectroscopic techniques including steady-state X-ray absorption spectroscopy (XAS), optical transient absorption (OTA), and X-ray transient (XTA) absorption spectroscopy. XAS results show that CIS NPs contain a large amount of surface Cu atoms with ≪four-coordination, which is more severe in CIS NPs with shorter nucleation times, indicating the presence of more Cu defect states in CIS NPs with smaller size particles. Using the combination of OTA and XTA spectroscopy, we show that electrons are trapped …

An Experiment-Based Model Quantifying Antimicrobial Activity Of Silver Nanoparticles On Escherichia Coli, Mohammad A. Haque, Riku Imamura, George A. Brown, Venkata R. Krishnamurthi, Isabelle I. Niyonshuti, Tiffany Marcelle, Leanne E. Mathurin, Jingyi Chen, Yong Wang

Physics Faculty Publications and Presentations

Silver nanoparticles (AgNPs) are well known to exhibit antimicrobial effects through plausible interactions with proteins and/or deoxyribonucleic acid inside the bacteria. Yet a quantitative understanding on the antimicrobial activities of AgNPs remains obscure. Here we conducted in-depth kinetic growth assays and colony-forming unit (CFU) assays on Escherichia coli (E. coli) cultured in AgNPs or Ag ion-containing growth media. Compared to the Ag-absent culture medium, it was found that the growth rate of the bacteria remained unaffected but the lag time of the bacterial growth was extended due to the presence of AgNPs or Ag ions. From the CFU-based time-kill curves, …

Photorelaxation And Photorepair Processes In Nucleic And Amino Acid Derivatives, Carlos E. Crespo-Hernández

Faculty Scholarship

No abstract provided.

Unravelling The Correlation Of Electronic Structure And Carrier Dynamics In Cuins2 Nanoparticles, Wenhui Hu, John Ludwig, Brian Pattengale, Sizhuo Yang, Cunming Liu, Xiaobing Zuo, Xiaoyi Zhang, Jier Huang

Chemistry Faculty Research and Publications

In this work, we report the direct correlation of photoinduced carrier dynamics and electronic structure of CuInS₂ (CIS) nanoparticles (NPs) using the combination of multiple spectroscopic techniques including steady-state X-ray absorption spectroscopy (XAS), optical transient absorption (OTA), and X-ray transient (XTA) absorption spectroscopy. XAS results show that CIS NPs contain a large amount of surface Cu atoms with ≪four-coordination, which is more severe in CIS NPs with shorter nucleation times, indicating the presence of more Cu defect states in CIS NPs with smaller size particles. Using the combination of OTA and XTA spectroscopy, we show that electrons are trapped …

Synergistic Interactions Of H2 And N2 With Molten Gallium In The Presence Of Plasma, Maria L. Carreon, Daniel F. Jaramillo-Cabanzo, Indira Chaudhuri, Madhu Menon, Mahendra K. Sunkara

Physics and Astronomy Faculty Publications

The present study examines the interaction of hydrogen and nitrogen plasmas with gallium in an effort to gain insights into the mechanisms behind the synergetic effect of plasma and a catalytic metal. Absorption/desorption experiments were performed, accompanied by theoretical-computational calculations. Experiments were carried out in a plasma-enhanced, Ga-packed, batch reactor and entailed monitoring the change in pressure at different temperatures. The results indicated a rapid adsorption/dissolution of the gas into the molten metal when gallium was exposed to plasma, even at a low temperature of 100 °C. The experimental observations, when hydrogen was used, indicate that gallium acts as a …

Sdss-Iv Manga: Spatially Resolved Star Formation Main Sequence And Li(N)Er Sequence, B. C. Hsieh, Lihwai Lin, J. H. Lin, H. A. Pan, C. H. Hsu, S. F. Sánchez, M. Cano-Díaz, Kai Zhang, Renbin Yan, J. K. Barrera-Ballesteros, M. Boquien, R. Riffel, J. Brownstein, I. Cruz-González, A. Hagen, H. Ibarra, K. Pan, D. Bizyaev, D. Oravetz, A. Simmons

Physics and Astronomy Faculty Publications

We present our study on the spatially resolved Hα and M_* relation for 536 star-forming and 424 quiescent galaxies taken from the MaNGA survey. We show that the star formation rate surface density (Σ_SFR), derived based on the Hα emissions, is strongly correlated with the M_* surface density (Σ_*) on kiloparsec scales for star-forming galaxies and can be directly connected to the global star-forming sequence. This suggests that the global main sequence may be a consequence of a more fundamental relation on small scales. On the other hand, our result suggests that …