Physical Sciences and Mathematics Commons^™

A Critical Assessment Of Stellar Mass Measurement Methods, Bahram Mobasher, Tomas Dahlen, Henry C. Ferguson, Viviana Acquaviva, Guillermo Barro, Steven L. Finkelstein, Adriano Fontana, Ruth Gruetzbauch, Seth Johnson, Yu Lu, Casey Papovich, Janine Pforr, Mara Salvato, Rachel S. Somerville, Tommy Wiklind, Stijn Wuyts, Matthew L.N. Ashby, Eric Bell, Christopher J. Conselice, Mark E. Dickinson, Sandra M. Faber, Giovanni Fazio, Kristian Finlator, Audrey Galametz, Eric Gawiser, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Yicheng Guo, Nimish Hathi, Dale Kocevski, Anton M. Koekemoer, David C. Koo, Jeffrey A. Newman, Naveen Reddy, Paola Santini, Risa H. Wechsler

Physics and Astronomy Faculty Publications

This is the second paper in a series aimed at investigating the main sources of uncertainty in measuring the observable parameters in galaxies from their spectral energy distributions (SEDs). In the first paper we presented a detailed account of the photometric redshift measurements and an error analysis of this process. In this paper we perform a comprehensive study of the main sources of random and systematic error in stellar mass estimates for galaxies, and their relative contributions to the associated error budget. Since there is no prior knowledge of the stellar mass of galaxies (unlike their photometric redshifts), we use …

Linear Algebra, Daniel Scully

Math Faculty Publications

Table of Contents:

1. Systems of Linear Equations and Matrices

• Systems of Linear Equations
• Elementary Row Operations
• Row Reduction and Reduced Row-Echelon Form
• Solutions of Systems of Linear Equations
• Matrix Operations
• Matrix Inverses

2. Euclidean 2-Space and 3-Space

• Vectors in the Plane and in Space
• The Dot Product
• Cross Product
• Lines in Space
• Planes in Space

3. Determinants

• The Definition of Determinant
• Elementary Row Operations and the Determinant
• Elementary Matrices and the Determinant
• Applications of the Determinant

4. Vector Spaces and Subspaces

• Vector Spaces
• Subspaces
• Linear Dependence and Independence
• Basis and Dimension

5. Linear Transformations

• Definition of Linear Transformation
• The …

Steps Towards Deciphering The Post-Polyketide Synthase Tailoring Steps In The Phoslactomycin Biosynthesis Pathway, Patience Marimo

Dissertations and Theses

Phoslactomycins (PLMs) are a group of natural products belonging to a polyketides class. These polyketides are synthesized by sequential reaction catalyzed by a collection of enzymes activities called polyketide synthases. A polyketide is a large class of diverse compounds that are characterized by more than two carbonyl groups connected by single intervening carbon atoms. In other words, a polyketide is a polymer whose monomer is a ketide. The PLMs are also known as phosphazomycins or phospholines. These compounds were isolated based on antifungal and antitumor activities. This array of promising biological activities has stimulated research into the field of PLMs …

Regioselectivity Of The Interaction Of Temozolomide With Borane And Boron Trifluoride, Okuma Emile Kasende, Jules Tshishimbi Muya, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

MP2 and B3LYP calculations are used to predict the most favorable site of temozolomide toward BH3 and BF3 which are classical Lewis acids. Binding energies, charge transfers, and bond length perturbations of the temozolomide in various complexes indicate that the N12 atom is the preferred attack site for BH3, while BF3 prefers the O17 atom. The interactions are quite strong, as much as 100 kJ/mol for BH3 and more than 60 kJ/mol for BF3. The molecular electrostatic potential surrounding temozolomide is most negative around the O atoms, which is unable to explain the energetic order of binding of the Lewis …

Modelling The Links Between Inflation, Output Growth, Inflation Uncertainty And Output Growth Uncertainty In The Frameworks Of Regime-Switching And Multiple Structural Breaks: Evidence From The G7 Countries., Kushal Banik Chowdhury Dr.

Doctoral Theses

One of the long-standing and most investigated issues in macroeconomics is the nature of the relationship between inflation and output growth. Given this relationship as a central point of intense interest, one strand of studies has focused on the levels of the two series, while, more recently, an overgrowing body of research has highlighted the importance of the effects which are due to both the levels and the uncertainties associated with these two variables. These studies raise a number of interesting issues regarding the relationship between inflation and output growth. First, is there any direct effect of inflation on output …

How Does “Collaboration” Occur At All? Remarks On Epistemological Issues Related To Understanding / Working With ‘The Other’, Don Faust, Judith Puncochar

Conference Presentations

Collaboration, if to occur successfully at all, needs to be based on careful representation and communication of each stakeholder’s knowledge. In this paper, we investigate, from a foundational logical and epistemological point of view, how such representation and communication can be accomplished. What we tentatively conclude, based on a careful delineation of the logical technicalities necessarily involved in such representation and communication, is that a complete representation is not possible. This inference, if correct, is of course rather discouraging with regard to what we can hope to achieve in the knowledge representations that we bring to our collaborations. We suggest …

Rows Vs. Columns: Randomized Kaczmarz Or Gauss-Seidel For Ridge Regression, Ahmed Hefny, Deanna Needell, Aaditya Ramdas

CMC Faculty Publications and Research

The Kaczmarz and Gauss-Seidel methods aim to solve a linear m × n system Xβ = y by iteratively refining the solution estimate; the former uses random rows of X to update β given the corresponding equations and the latter uses random columns of X to update corresponding coordinates in β. Interest in these methods was recently revitalized by a proof of Strohmer and Vershynin showing linear convergence in expectation for a randomized Kaczmarz method variant (RK), and a similar result for the randomized Gauss-Seidel algorithm (RGS) was later proved by Lewis and Leventhal. Recent work unified the analysis of …

Cosm News, Georgia Southern University

College of Science and Mathematics News (2012-2019)

• Coral Reproduction Workshop

Measurements Of The ϒ(1s), ϒ(2s), And ϒ(3s)Differential Cross Sections In Pp Collisions At √S=7 Tev, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

Differential cross sections as a function of transverse momentum pTare presented for the production of ϒ(nS)(n=1, 2, 3) states decaying into a pair of muons. Data corresponding to an integrated luminosity of 4.9fb−1in pp collisions at √s=7 TeVwere collected with the CMS detector at the LHC. The analysis selects events with dimuon rapidity |y| <1.2and dimuon transverse momentum in the range 10

Population Genetic Structure Of The Dwarf Seahorse (Hippocampus Zosterae) In Florida, Nathan Fedrizzi, Melanie L. J. Stiassny, J. T. Boehm, Eric R. Dougherty, George Amato, Martin Mendez

Publications and Research

The dwarf seahorse (Hippocampus zosterae) is widely distributed throughout near-shore habitats of the Gulf of Mexico and is of commercial significance in Florida, where it is harvested for the aquarium and curio trades. Despite its regional importance, the genetic structure of dwarf seahorse populations remains largely unknown. As an aid to ongoing conservation efforts, we employed three commonly applied mtDNA markers (ND4, DLoop and CO1) to investigate the genetic structuring of H. zosterae in Florida using samples collected throughout its range in the state. A total of 1450 bp provided sufficient resolution to delineate four populations of dwarf seahorses, as …

Improved Terahertz Modulation Using Germanium Telluride (Gete) Chalcogenide Thin Films, Alexander H. Gwin, Christopher H. Kodama, Tod V. Laurvick, Ronald Coutu Jr., Philip F. Taday

Faculty Publications

We demonstrate improved terahertz (THz) modulation using thermally crystallized germanium telluride (GeTe) thin films. GeTe is a chalcogenide material that exhibits a nonvolatile, amorphous to crystalline phase change at approximately 200 °C, as well as six orders of magnitude decreased electrical resistivity. In this study, amorphous GeTe thin films were sputtered on sapphire substrates and then tested using THz time-domain spectroscopy (THz-TDS). The test samples, heated in-situ while collecting THz-TDS measurements, exhibited a gradual absorbance increase, an abrupt nonvolatile reduction at the transition temperature, followed by another gradual increase in absorbance. The transition temperature was verified by conducting similar thermal …

The Rapid Formation Of Functional Monolayers On Silicon Under Mild Conditions, Simone Ciampi, Erwann Luais, Michael James, Moinul Choudhury, Nadim Darwish, J Gooding

Michael C James

We report on an exceedingly mild chemical functionalization of hydrogen-terminated Si(100) with unactivated and unprotected bifunctional α,ω-dialkynes. Monolayer formation occurs rapidly in the dark, and at room temperature, from dilute solutions of an aromatic-conjugated acetylene. The method addresses the poor reactivity of p-type substrates under mild conditions. We suggest the importance of several factors, including an optimal orientation for electron transfer between the adsorbate and the Si surface, conjugation of the acetylenic function with a π-system, as well as the choice of a solvent system that favors electron transfer and screens Coulombic interactions between surface holes and electrons. The passivated …

Modeling Multiple-Mode Systems With Predictive State Representations, Britton Wolfe, Michael James, Satinder Singh

Michael C James

Predictive state representations (PSRs) are a class of models that represent the state of a dynamical system as a set of predictions about future events. This work introduces a class of structured PSR models called multi-mode PSRs (MMPSRs), which were inspired by the problem of modeling traffic. In general, MMPSRs can model uncontrolled dynamical systems that switch between several modes of operation. An important aspect of the model is that the modes must be recognizable from a window of past and future observations. Allowing modes to depend upon future observations means the MMPSR can model systems where the mode cannot …

U.S. Drought Monitor, July 21, 2015, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for July 21, 2015 (7/21/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Observational Properties Of Simulated Galaxies In Overdense And Average Regions At Redshifts Z ≃ 6–12, Hidenobu Yajima, Isaac Shlosman, Emilio Romano-Díaz, Kentaro Nagamine

Physics and Astronomy Faculty Publications

We use high-resolution zoom-in cosmological simulations of galaxies of Romano-Díaz et al., post-processing them with a panchromatic three-dimensional radiation transfer code to obtain the galaxy UV luminosity function (LF) at z ≃ 6–12. The galaxies are followed in a rare, heavily overdense region within a ∼5σ density peak, which can host high-z quasars, and in an average density region, down to the stellar mass of M_star ∼ 4 × 10⁷ M_⊙. We find that the overdense regions evolve at a substantially accelerated pace – the most massive galaxy has grown to M_star ∼ 8.4 …

A Multivariate Modeling Approach For Generating Ensemble Climatology Forcing For Hydrologic Applications, Sepideh Khajehei

Dissertations and Theses

Reliability and accuracy of the forcing data plays a vital role in the Hydrological Streamflow Prediction. Reliability of the forcing data leads to accurate predictions and ultimately reduction of uncertainty. Currently, Numerical Weather Prediction (NWP) models are developing ensemble forecasts for various temporal and spatial scales. However, it is proven that the raw products of the NWP models may be biased at the basin scale; unlike model grid scale, depending on the size of the catchment. Due to the large space-time variability of precipitation, bias-correcting the ensemble forecasts has proven to be a challenging task. In recent years, Ensemble Pre-Processing …

Magnetism Of Zno Nanoparticles: Dependence On Crystallite Size And Surfactant Coating, Aaron Thurber, Geoffrey Beausoleil, Gordon Alanko, Joshua Anghel, Michael Jones, Lydia Johnson, Jianhui Zhang, Charles Hanna, Dmitri Tenne, Alex Punnoose

Lydia Johnson

Many recent reports on magnetism in otherwise nonmagnetic oxides have demonstrated that nanoparticle size, surfactant coating, or doping with magnetic ions produces room-temperature ferromagnetism. Specifically, ZnO has been argued to be a room-temperature ferromagnet through all three of these methods in various experimental studies. For this reason, we have prepared a series of 1% Fe doped ZnO nanoparticle samples using a single forced hydrolysis co-precipitation synthesis method from the same precursors, while varying size (6 – 15 nm) and surface coating concentration to study the combined effects of these two parameters. Size was controlled by modifying the water concentration. Surfactant …

Transition Metal Dopants Essential For Producing Ferromagnetism In Metal Oxide Nanoparticles, Lydia M. Johnson, Aaron Thurber, Joshua Anghel, Maryam Sabetian, Mark H. Engelhard, Dmitri A. Tenne, Charles B. Hanna, Alex Punnoose

Lydia Johnson

Recent claims that ferromagnetism can be produced in nanoparticles of metal oxides without the presence of transition metal dopants have been challenged in this work by investigating 62 high quality well-characterized nanoparticle samples of both undoped and Fe doped (0-10% Fe) ZnO. The undoped ZnO nanoparticles showed zero or negligible magnetization, without any dependence on the nanoparticle size. However, chemically synthesized Zn1-xFexO nanoparticles showed clear ferromagnetism, varying systematically with Fe concentration. Furthermore, the magnetic properties of Zn1-xFexO nanoparticles showed strong dependence on the reaction media used to prepare the samples. The zeta potentials of the Zn1-xFexO nanoparticles prepared using different …

Come For The Content, Stay For The Community, Hilary Eppley

Hilary J. Eppley

No abstract provided.

Ignoring Nature: Why We Do It, The Dire Consequences, And The Need For A Paradigm Shift To Save Animals, Habitats, And Ourselves, Marc Bekoff, Sarah Bexell

Sarah M. Bexell, PhD

The article discusses the importance of biodiversity and on how people protect animals and habitats. It describes the conservation psychology and conservation social work. It suggests that there will be fewer people who will actually be able to make a positive difference in the relationships with animals and ecosystems.

Switching Behaviors Of Graphene-Boron Nitride Nanotube Heterojunctions, Vyom Parashar, Corentin Durand, Boyi Hao, Rodrigo Amorim, Ravindra Pandey, Bishnu Tiwari, Dongyan Zhang, Yang Liu, An-Ping Li, Yoke Khin Yap

Department of Physics Publications

High electron mobility of graphene has enabled their application in high-frequency analogue devices but their gapless nature has hindered their use in digital switches. In contrast, the structural analogous, h-BN sheets and BN nanotubes (BNNTs) are wide band gap insulators. Here we show that the growth of electrically insulating BNNTs on graphene can enable the use of graphene as effective digital switches. These graphene-BNNT heterojunctions were characterized at room temperature by four-probe scanning tunneling microscopy (4-probe STM) under real-time monitoring of scanning electron microscopy (SEM). A switching ratio as high as 10⁵ at a turn-on voltage as low …

A Numerical Simulation Of Cosmic-Ray Modulation Near The Heliopause, Xi Luo, Ming Zhang, Marius S. Potgieter, Xueshang Feng, Nikolai V. Pogorelov

Aerospace, Physics, and Space Science Faculty Publications

Based on a hybrid galactic cosmic-ray transport model, which incorporated MHD global heliospheric data into Parker's cosmic-ray transport equation, we studied the behavior of the transport of galactic cosmic rays and the corresponding gradients in their flux near the heliopause (HP). We found that, (1) by increasing the ratio of the parallel diffusion coefficient to the perpendicular diffusion coefficient in the interstellar magnetic field of the outer heliosheath, the simulated radial flux near the HP increases as well. As the ratio multiplying factor reached 10^10, the radial flux experienced a sudden jump near the HP, similar to what Voyager 1 …

Characterization And Evaluation Of The Bakken Petroleum System For Co2 Enhanced Oil Recovery, James A. Sorensen, Jason R. Braunberger, Guoxiang (Gavin) Liu, Steven A. Smith, Steven A. Hawthorne, Edward N. Steadman, John A. Harju

EERC Publications

Application of the findings to the U.S. Department of Energy methodology for estimating CO₂ EOR and storage capacity suggests that 4 Bbbl (billion barrels) to 7 Bbbl of incremental oil could be produced from the Bakken, resulting in a net storage of 1.9 to 3.2 billion tons of CO₂.

Stellar Metallicity Gradients In Sdss Galaxies, Benjamin Roig, Michael R. Blanton, Renbin Yan

Physics and Astronomy Faculty Publications

We infer stellar metallicity and abundance ratio gradients for a sample of red galaxies in the Sloan Digital Sky Survey (SDSS) Main galaxy sample. Because this sample does not have multiple spectra at various radii in a single galaxy, we measure these gradients statistically. We separate galaxies into stellar mass bins, stack their spectra in redshift bins, and calculate the measured absorption-line indices in projected annuli by differencing spectra in neighboring redshift bins. After determining the line indices, we use stellar population modeling from the EZ_Ages software to calculate ages, metallicities, and abundance ratios within each annulus. Our data cover …

Optical Detection Of The Pictor A Jet And Tidal Tail: Evidence Against An Ic/Cmb Jet, Eric S. Gentry, Herman L. Marshall, Martin J. Hardcastle, Eric S. Perlman, Mark Birkinshaw, Diana M. Worrall, Emil Lenc, Aneta Siemiginowska, Claudia Megan Urry

Aerospace, Physics, and Space Science Faculty Publications

New images of the FR II radio galaxy Pictor A from the Hubble Space Telescope reveal a previously undiscovered tidal tail, as well as a number of jet knots coinciding with a known X-ray and radio jet. The tidal tail is approximately 5″ wide (3 kpc projected), starting 18″ (12 kpc) from the center of Pictor A, and extends more than 90″ (60 kpc). The knots are part of a jet observed to be about 4′ (160 kpc) long, extending to a bright hotspot. These images are the first optical detections of this jet, and by extracting knot flux densities …

Evaluating Global Sensitivity Analysis Methods For Hydrologic Modeling Over The Columbia River Basin, Maysoun Ayad Hameed

Dissertations and Theses

Global Sensitivity Analysis (GSA) approach helps to identify the effectiveness of model parameters or inputs and thus provides essential information about the model performance. The effects of 14 parameters and one input (forcing data) of the Sacramento Soil Moisture Accounting (SAC-SMA) model are analyzed by using two GSA methods: Sobol' and Fourier Amplitude Sensitivity Test (FAST). The simulations are carried out over five sub-basins within the Columbia River Basin (CRB) for three different periods: one-year, four-year, and seven-year. The main parameter sensitivities (first-order) and the interactions sensitivities (second-order) are evaluated in this study. Our results show that some hydrological processes …

Caffeine Consumption Contributes To Skin Intrinsic Fluorescence In Type 1 Diabetes., Karen M Eny, Trevor J Orchard, Rachel Grace Miller, John Maynard, Denis M Grant, Tina Costacou, Patricia A. Cleary, Barbara H Braffett, Andrew D Paterson, Dcct/Edic Research Group

GW Biostatistics Center

Background: A variant (rs1495741) in the gene for the N-acetyltransferase 2 (NAT2) protein is associated with skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation end products and other fluorophores in the skin. Because NAT2 is involved in caffeine metabolism, we aimed to determine whether caffeine consumption is associated with SIF and whether rs1495741 is associated with SIF independently of caffeine.

Materials and Methods: SIF was measured in 1,181 participants with type 1 diabetes from the Epidemiology of Diabetes Interventions and Complications study. Two measures of SIF were used: SIF1, using a 375-nm excitation light-emitting diode (LED), and …

Generation Of Molecular Complexity From Cyclooctatetraene: Preparation Of Aminobicyclo[5.1.0]Octitols, Mohamed F. El-Mansy, Matthew Flister, Sergey Lindeman, Kelsey S. Kalous, Daniel S. Sem, William Donaldson

Chemistry Faculty Research and Publications

A series of eight stereoisomeric N-(tetrahydroxy bicyclo-[5.1.0]oct-2S*-yl)phthalimides were prepared in one to four steps from N-(bicyclo[5.1.0]octa-3,5-dien-2-yl)phthalimide (±)-7, which is readily available from cyclooctatetraene (62 % yield). The structural assignments of the stereoisomers were established by ¹H NMR spectral data as well as X-ray crystal structures for certain members. The outcomes of several epoxydiol hydrolyses, particularly ring contraction and enlargement, are of note. The isomeric phthalimides as well as the free amines did not exhibit β-glucosidase inhibitory activity at a concentration of less than 100 μM.

Measuring Infrared Surface Brightness Fluctuation Distances With Hst Wfc3: Calibration And Advice, Joseph B. Jensen, John P. Blakeslee, Zachary Gibson, Hyun Chul Lee, Michele Cantiello, Gabriella Raimondo, Nathan Boyer, Hyejeon Cho

Physics and Astronomy Faculty Publications and Presentations

We present new calibrations of the near-infrared (near-IR) surface brightness fluctuation (SBF) distance method for the F110W (J110) and F160W (H160) bandpasses of the Wide Field Camera 3 Infrared Channel (WFC3/IR) on the Hubble Space Telescope. The calibrations are based on data for 16 early-type galaxies in the Virgo and Fornax clusters observed with WFC3/IR and are provided as functions of both the optical (g475-z850 ) and near-infrared (J110-H160) colors. The scatter about the linear calibration relations for the luminous red galaxies in the sample is approximately 0.10 mag, corresponding to a statistical error of 5% in distance. Our results …

Determination Of Extracellular Molecules Produced By Vibrio Harveyi Using Ms/Ms, Jose G. Roble

FIU Electronic Theses and Dissertations

Quorum sensing (QS) is a process that allows bacteria to sense the population density of cells around them by communicating with each other via autoinducer molecules. This cross-communication is crucial in the regulation of bacterial processes such as bioluminescence, virulence, and biofilm formation. Previous research by Milburn and Makemson on Vibrio harveyi suggested that in addition of the known biosynthesis of three well-characterized autoinducers, dozens of unknown molecules are also produced and released to the environment by V. harveyi. This study was performed using electrospray tandem mass spectrometry with the purpose of detection and characterization of the extracellular molecules …