Physical Sciences and Mathematics Commons^™

Mono-N-Acyl-2,6-Diaminopimelic Acid Derivatives: Analysis By Electromigration And Spectroscopic Methods And Examination Of Enzyme Inhibitory Activity, Jan Hlaváček, Miloslava Vítovcová, Petra Sázelová, Jan Pícha, Václav Vaněk, Miloš Buděšínský, Jiří Jiráček, Danuta M. Gillner, Richard C. Holz, Ivan Mikšík, Václav Kašička

Chemistry Faculty Research and Publications

Thirteen mono-N-acyl derivatives of 2,6-diaminopimelic acid (DAP)—new potential inhibitors of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE; EC 3.5.1.18)—were analyzed and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and two capillary electromigration methods: capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). Structural features of DAP derivatives were characterized by IR and NMR spectroscopies, whereas CZE and MEKC were applied to evaluate their purity and to investigate their electromigration properties. Effective electrophoretic mobilities of these compounds were determined by CZE in acidic and alkaline background electrolytes (BGEs) and by MEKC in acidic and alkaline BGEs …

Protein Expression, Characterization And Activity Comparisons Of Wild Type And Mutant Dusp5 Proteins, Jaladhi Nayak, Adam J. Gastonguay, Marat R. Talipov, Padmanabhan Vakeel, Elise A. Span, Kelsey S. Kalous, Raman G. Kutty, David R. Jensen, Phani Raj Pokkuluri, Daniel S. Sem, Rajendra Rathore, Ramani Ramchandran

Chemistry Faculty Research and Publications

Background

The mitogen-activated protein kinases (MAPKs) pathway is critical for cellular signaling, and proteins such as phosphatases that regulate this pathway are important for normal tissue development. Based on our previous work on dual specificity phosphatase-5 (DUSP5), and its role in embryonic vascular development and disease, we hypothesized that mutations in DUSP5 will affect its function.

Results

In this study, we tested this hypothesis by generating full-length glutathione-S-transferase-tagged DUSP5 and serine 147 proline mutant (S147P) proteins from bacteria. Light scattering analysis, circular dichroism, enzymatic assays and molecular modeling approaches have been performed to extensively characterize the protein form and function. …

Quantification Of The Statistical Effects Of Spatiotemporal Processing Of Nontask Fmri Data, M. Muge Karaman, Andrew S. Nencka, Iain P. Bruce, Daniel B. Rowe

Mathematics, Statistics and Computer Science Faculty Research and Publications

Nontask functional magnetic resonance imaging (fMRI) has become one of the most popular noninvasive areas of brain mapping research for neuroscientists. In nontask fMRI, various sources of “noise” corrupt the measured blood oxygenation level-dependent signal. Many studies have aimed to attenuate the noise in reconstructed voxel measurements through spatial and temporal processing operations. While these solutions make the data more “appealing,” many commonly used processing operations induce artificial correlations in the acquired data. As such, it becomes increasingly more difficult to derive the true underlying covariance structure once the data have been processed. As the goal of nontask fMRI studies …

Correction To “Master Regulators, Regulatory Networks, And Pathways Of Glioblastoma Subtypes”, Serdar Bozdag, Aiguo Li, Mehmet Baysan, Howard A. Fine

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.

Remarks On Characterizations Of Malinowska And Szynal, Gholamhossein Hamedani, Z. Javanshiri, Mehdi Maadooliat, A. Yazdani

Mathematics, Statistics and Computer Science Faculty Research and Publications

The problem of characterizing a distribution is an important problem which has recently attracted the attention of many researchers. Thus, various characterizations have been established in many different directions. An investigator will be vitally interested to know if their model fits the requirements of a particular distribution. To this end, one will depend on the characterizations of this distribution which provide conditions under which the underlying distribution is indeed that particular distribution. In this work, several characterizations of Malinowska and Szynal (2008) for certain general classes of distributions are revisited and simpler proofs of them are presented. These characterizations are …

Structure, Stability, And Substituent Effects In Aromatic S-Nitrosothiols: The Crucial Effect Of A Cascading Negative Hyperconjugation/Conjugation Interaction, Matthew Flister, Qadir K. Timerghazin

Chemistry Faculty Research and Publications

Aromatic S-nitrosothiols (RSNOs) are of significant interest as potential donors of nitric oxide and related biologically active molecules. Here, we address a number of poorly understood properties of these species via a detailed density functional theory and the natural bond orbital (NBO) investigation of the parent PhSNO molecule. We find that the characteristic perpendicular orientation of the −SNO group relative to the phenyl ring is determined by a combination of the steric factors and the donor–acceptor interactions including, in particular, a cascading orbital interaction involving electron delocalization from the oxygen lone pair to the σ-antibonding S–N orbital and then …

The Antisymmetry Betweenness Axiom And Hausdorff Continua, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

An interpretation of betweenness on a set satisfies the antisymmetry axiom at a point a if it is impossible for each of two distinct points to lie between the other and a. In this paper we study the role of antisymmetry as it applies to the K-interpretation of betweenness in a Hausdorff continuum X, where a point c lies between points a and b exactly when every subcontinuum of X containing both a and b contains c as well.

Exploring The Relationship Between K-8 Prospective Teachers’ Algebraic Thinking Proficiency And The Questions They Pose During Diagnostic Algebraic Thinking Interviews, Leigh A. Van Den Kieboom, Marta T. Magiera, John C. Moyer

Mathematics, Statistics and Computer Science Faculty Research and Publications

In this study, we explored the relationship between prospective teachers’ algebraic thinking and the questions they posed during one-on-one diagnostic interviews that focused on investigating the algebraic thinking of middle school students. To do so, we evaluated prospective teachers’ algebraic thinking proficiency across 125 algebra-based tasks and we analyzed the characteristics of questions they posed during the interviews. We found that prospective teachers with lower algebraic thinking proficiency did not ask any probing questions. Instead, they either posed questions that simply accepted and affirmed student responses or posed questions that guided the students toward an answer without probing student thinking. …

Relatively Congruence-Free Regular Semigroups, Peter Jones

Mathematics, Statistics and Computer Science Faculty Research and Publications

Yu, Wang, Wu and Ye call a semigroup S τ -congruence-free, where τ is an equivalence relation on S, if any congruence ρ on S is either disjoint from τ or contains τ . A congruence-free semigroup is then just an ω-congruence-free semigroup, where ω is the universal relation. They determined the completely regular semigroups that are τ -congruence-free with respect to each of the Green’s relations. The goal of this paper is to extend their results to all regular semigroups. Such a semigroup is J –congruence-free if and only if it is either a semilattice or has …

Some Remarks On Recent Characterizations Of Continuous Distributions, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

We would closely look at two recent published papers dealing with characterizations of certain univariate continuous distributions. We shall explain that the main results reported lack important assumptions. These results nevertheless are based on the conditional expectations of monotone functions of the generalized order statistics. We will also mention that similar results have recently been reported without the assumption of monotonicity of the functions of the generalized order statistics.

Interactive Tool For Visualization Of Adiabatic Adjustment In Aph Coordinates For Computational Studies Of Vibrational Motion And Chemical Reactions, Alexander Teplukhin, Dmitri Babikov

Chemistry Faculty Research and Publications

The adiabatically-adjusting principal-axes hyperspherical (APH) coordinates reviewed in this letter are one of the best coordinate sets developed for computational treatment of spectroscopy and dynamics of triatomic molecules. Unfortunately, it is not so easy to understand and interpret them, compared to other simpler coordinates, like valence coordinates or Jacobi coordinates. To address this issue, we developed a desktop application called APHDemo. This tool visualizes the process of adjustment of the APH coordinates to the shape of a triatomic molecule during molecular vibrations or chemical reaction, and helps to understand their physical meaning without going into complicated math.

Preparation Of Cyclohexenones From Acyclic (Pentadienyl)Iron(1+) Cations: Synthetic Studies Directed Toward The A-Ring Of Dihydrotachysterols, Charles Felix Manful, William A. Donaldson

Chemistry Faculty Research and Publications

The reaction of tricarbonyl(3-methylpentadienyl)iron(1+) cation (7) with stabilized carbon nucleophiles affords 4-methyl-5-substituted cyclohexenones. Reaction of 7 with sodium bis[(+)-2-phenylcyclohexyl]malonate afforded a mixture of diastereomers (de = 60 %); the diastereomeric allylic alcohols resulting from Luche reduction of this mixture were separable by column chromatography. Issues in diastereoselectivity in approaches to synthons for the A-ring of the tachysterols from these cyclohexenones are reported.

Generalized Exponentiated Moment Exponential Distribution, Zafar Iqbal, Syed Anwer Hasnain, Muhammad Salman, Munir Ahmad, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

Moment distributions have a vital role in mathematics and statistics, in particular in probability theory, in the perspective research related to ecology, reliability, biomedical field, econometrics, survey sampling and in life-testing. Hasnain (2013) developed an exponentiated moment exponential (EME) distribution and discussed some of its important properties. In the present work, we propose a generalization of EME distribution which we call it generalized EME (GEME) distribution and develop various properties of the distribution. We also present characterizations of the distribution in terms of conditional expectation as well as based on hazard function of the GEME random variable.

Characterizations Of A Class Of Distributions By Dual Generalized Order Statistics And Truncated Moments, Filippo Domma, Gholamhossein Hamedani

Mathematics, Statistics and Computer Science Faculty Research and Publications

The problem of characterizing a distribution is an important problem which has recently attracted the attention of many researchers. Thus, various characterizations have been established in many different directions. The present work deals with the characterizations of a general class of distributions. These characterizations are based on: (i) a simple relationship between two truncated moments, (ii) truncated moment of certain functions of the nth order statistic, (iii) single truncated moment of certain functions of the random variable and (iv) moments of dual generalized order statistics.We like to mention that the characterization (i) which is expressed in terms of the ratio …

Synthesis Of Homo- And Heterobimetallic NiIi–MIi (M = Fe, Co, Ni, Zn) Complexes Based On An Unsymmetric Ligand Framework: Structures, Spectroscopic Features, And Redox Properties, Denan Wang, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

Several homo- and heterobimetallic Ni^II–M^II complexes (M^II = Fe, Co, Ni, Zn) supported by an unsymmetric polydentate ligand (L₁³⁻) are reported (L₁³⁻ is the trianion of 2-[bis(2-hydroxy-3,5-tert-butylphenyl)aminomethyl]-4-methyl-6-[(2-pyridylmethyl)iminomethyl]phenol). The L₁³⁻ chelate provides two distinct coordination environments: a planar tridentate {N₂O} site (A) and a tetradentate {NO₃} site (B). Reaction of L₁³⁻ with equimolar amounts of Ni^II and M^II salts provides bimetallic complexes in which the Ni^II ion exclusively occupies the tetragonal A-site and the M^II ion is found …

Existence Of Disjoint Weakly Mixing Operators That Fail To Satisfy The Disjoint Hypercyclicity Criterion, Rebecca Sanders, Stanislav Shkarin

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.

Pharyngeal And Cervical Cancer Incidences Significantly Correlate With Personal Uv Doses Among Whites In The United States, Dianne E. Godar, Rong Tang, Stephen Merrill

Mathematics, Statistics and Computer Science Faculty Research and Publications

Because we found UV-exposed oral tissue cells have reduced DNA repair and apoptotic cell death compared with skin tissue cells, we asked if a correlation existed between personal UV dose and the incidences of oral and pharyngeal cancer in the United States. We analyzed the International Agency for Research on Cancer's incidence data for oral and pharyngeal cancers by race (white and black) and sex using each state's average annual personal UV dose. We refer to our data as ‘white’ rather than ‘Caucasian,’ which is a specific subgroup of whites, and ‘black’ rather than African-American because blacks from other countries …

Towards A Lightweight Approach For Modding Serious Educational Games: Assisting Novice Designers, Jacob Dahleen, Alex Hunsberger, Ryan Weber, Dennis Brylow, C. Shaun Longstreet, Kendra M. L. Cooper

Mathematics, Statistics and Computer Science Faculty Research and Publications

Serious educational games (SEGs) are a growing segment of the education community’s pedagogical toolbox. Effectively creating such games remains challenging, as teachers and industry trainers are content experts; typically they are not game designers with the theoretical knowledge and practical experience needed to create a quality SEG. Here, a lightweight approach to interactively explore and modify existing SEGs is introduced, a toll that can be broadly adopted by educators for pedagogically sound SEGs. Novice game designers can rapidly explore the educational and traditional elements of a game, with a stress on tracking the SEG learning objectives, as well as allowing …

Chitosan-Cellulose Composite For Wound Dressing Material. Part 2. Antimicrobial Activity, Blood Absorption Ability, And Biocompatibility, April Harkins, Simon Duri, Luther C. Kloth, Chieu D. Tran

Clinical Lab Sciences Faculty Research and Publications

Chitosan (CS), a polysaccharide derived from chitin, the second most abundant polysaccharide, is widely used in the medical world because of its natural and nontoxic properties and its innate ability for antibacterial and hemostasis effects. In this study, the novel composites containing CS and cellulose (CEL) (i.e., [CEL + CS]), which we have previously synthesized using a green and totally recyclable method, were investigated for their antimicrobial activity, absorption of anticoagulated whole blood, anti-inflammatory activity through the reduction of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and the biocompatibility with human fibroblasts. The [CEL + CS] composites were found to …

Better Physical Activity Classification Using Smartphone Acceleration Sensor, Muhammad Arif, Mohsin Bilal, Ahmed Kattan, Sheikh Iqbal Ahamed

Mathematics, Statistics and Computer Science Faculty Research and Publications

Obesity is becoming one of the serious problems for the health of worldwide population. Social interactions on mobile phones and computers via internet through social e-networks are one of the major causes of lack of physical activities. For the health specialist, it is important to track the record of physical activities of the obese or overweight patients to supervise weight loss control. In this study, acceleration sensor present in the smartphone is used to monitor the physical activity of the user. Physical activities including Walking, Jogging, Sitting, Standing, Walking upstairs and Walking downstairs are classified. Time domain features are extracted …

Dilution Of Dipolar Interactions In A Spin-Labeled, Multimeric Metalloenzyme For Deer Studies, Mahesh Aitha, Timothy K. Richmond, Zhenxin Hu, Alyssa Hetrick, Raquel Reese, Althea Gunther, Robert Mccarrick, Brian Bennett, Michael W. Crowder

Physics Faculty Research and Publications

The metallo-β-lactamases (MβLs), which require one or two Zn(II) ions in their active sites for activity, hydrolyze the amide bond in β-lactam-containing antibiotics, and render the antibiotics inactive. All known MβLs contain a mobile element near their active sites, and these mobile elements have been implicated in the catalytic mechanisms of these enzymes. However little is known about the dynamics of these elements. In this study, we prepared a site-specific, double spin-labeled analog of homotetrameric MβL L1 with spin labels at positions 163 and 286 and analyzed the sample with DEER (double electron electron resonance) spectroscopy. Four unique distances were …

Fluorescence2d: Software For Accelerated Acquisition And Analysis Of Two-Dimensional Fluorescence Spectra, Evgeni L. Kovrigin

Chemistry Faculty Research and Publications

The Fluorescence2D is free software that allows analysis of two-dimensional fluorescence spectra obtained using the accelerated “triangular” acquisition schemes. The software is a combination of Python and MATLAB-based programs that perform conversion of the triangular data, display of the two-dimensional spectra, extraction of 1D slices at different wavelengths, and output in various graphic formats.

Electrochemistry And Spectroelectrochemistry Of 1,4-Dinitrobenzene In Acetonitrile And Room-Temperature Ionic Liquids: Ion-Pairing Effects In Mixed Solvents, Abderrahman Atifi, Michael D. Ryan

Chemistry Faculty Research and Publications

Room-temperature ionic liquids (RTILs) have been shown to have a significant effect on the redox potentials of compounds such as 1,4-dinitrobenzene (DNB), which can be reduced in two one-electron steps. The most noticeable effect is that the two one-electron waves in acetonitrile collapsed to a single two-electron wave in a RTIL such as butylmethyl imidazolium-BF₄ (BMImBF₄). In order to probe this effect over a wider range of mixed-molecular-solvent/RTIL solutions, the reduction process was studied using UV–vis spectroelectrochemistry. With the use of spectroelectrochemistry, it was possible to calculate readily the difference in E°’s between the first and …

The Inferred Cardiogenic Gene Regulatory Network In The Mammalian Heart, Jason Bazil, Karl D. Stamm, Xing Li, Raghuram Thiagarajan, Timonthy J. Nelson, Aoy Tomita-Mitchell, Daniel A. Beard

Mathematics, Statistics and Computer Science Faculty Research and Publications

Cardiac development is a complex, multiscale process encompassing cell fate adoption, differentiation and morphogenesis. To elucidate pathways underlying this process, a recently developed algorithm to reverse engineer gene regulatory networks was applied to time-course microarray data obtained from the developing mouse heart. Approximately 200 genes of interest were input into the algorithm to generate putative network topologies that are capable of explaining the experimental data via model simulation. To cull specious network interactions, thousands of putative networks are merged and filtered to generate scale-free, hierarchical networks that are statistically significant and biologically relevant. The networks are validated with known gene …

A Deep Chandra Acis Survey Of M83, Knox S. Long, Kip D. Kuntz, William P. Blair, Leith Godfrey, Paul P. Plucinsky, Roberto Soria, Christopher Stockdale, P. Frank Winkler

Physics Faculty Research and Publications

We have obtained a series of deep X-ray images of the nearby galaxy M83 using Chandra, with a total exposure of 729 ks. Combining the new data with earlier archival observations totaling 61 ks, we find 378 point sources within the D₂₅ contour of the galaxy. We find 80 more sources, mostly background active galactic nuclei (AGNs), outside of the D₂₅ contour. Of the X-ray sources, 47 have been detected in a new radio survey of M83 obtained using the Australia Telescope Compact Array. Of the X-ray sources, at least 87 seem likely to be supernova remnants …

Counting Independent Sets Of A Fixed Size In Graphs With Given Minimum Degree, John Engbers, David Galvin

Mathematics, Statistics and Computer Science Faculty Research and Publications

Galvin showed that for all fixed δ and sufficiently large n, the n-vertex graph with minimum degree δ that admits the most independent sets is the complete bipartite graph . He conjectured that except perhaps for some small values of t, the same graph yields the maximum count of independent sets of size t for each possible t. Evidence for this conjecture was recently provided by Alexander, Cutler, and Mink, who showed that for all triples with , no n-vertex bipartite graph with minimum degree δ admits more independent sets of size t than . …

Beta Burr Xii Or Five Parameter Beta Lomax Distribution: Remarks And Characterizations, Z. Javanshiri, Mehdi Maadooliat

Mathematics, Statistics and Computer Science Faculty Research and Publications

The distributions taken up in two recently published papers are compared and certain characterizations of them are presented. These characterizations are based on: (i) a simple relationship between two truncated moments; (ii) truncated moments of certain functions of the nth order statistic; (iii) truncated moments of certain functions of the random variable.

Regularized Multivariate Regression Models With Skew-T Error Distributions, Lianfu Chen, Mohsen Pourahmadi, Mehdi Maadooliat

Mathematics, Statistics and Computer Science Faculty Research and Publications

We consider regularization of the parameters in multivariate linear regression models with the errors having a multivariate skew-t distribution. An iterative penalized likelihood procedure is proposed for constructing sparse estimators of both the regression coefficient and inverse scale matrices simultaneously. The sparsity is introduced through penalizing the negative log-likelihood by adding L₁-penalties on the entries of the two matrices. Taking advantage of the hierarchical representation of skew-t distributions, and using the expectation conditional maximization (ECM) algorithm, we reduce the problem to penalized normal likelihood and develop a procedure to minimize the ensuing objective function. Using a …

In Vitro Biosynthesis And Chemical Identification Of Udp-N-Acetyl-D-Quinovosamine (Udp-D-Quinac), Tiezheng Li, Laurie Simonds, Evgeni L. Kovrigin, K. Dale Noel

Chemistry Faculty Research and Publications

N-acetyl-d-quinovosamine (2-acetamido-2,6-dideoxy-d-glucose, QuiNAc) occurs in the polysaccharide structures of many Gram-negative bacteria. In the biosynthesis of QuiNAc-containing polysaccharides, UDP-QuiNAc is the hypothetical donor of the QuiNAc residue. Biosynthesis of UDP-QuiNAc has been proposed to occur by 4,6-dehydration of UDP-N-acetyl-d-glucosamine (UDP-GlcNAc) to UDP-2-acetamido-2,6-dideoxy-d-xylo-4-hexulose followed by reduction of this 4-keto intermediate to UDP-QuiNAc. Several specific dehydratases are known to catalyze the first proposed step. A specific reductase for the last step has not been demonstrated in vitro, but previous mutant analysis suggested that Rhizobium etli gene wreQ might encode this reductase. Therefore, this gene was cloned and expressed …

The Dimerization Domain In Dape Enzymes Is Required For Catalysis, Boguslaw Nocek, Anna Starus, Magdalena Makowska-Grzyska, Blanca Gutierrez, Stephen Sanchez, Robert Jedrzejczak, Jamey C. Mack, Kenneth W. Olsen, Andzrej Joachimiak, Richard C. Holz

Chemistry Faculty Research and Publications

The emergence of antibiotic-resistant bacterial strains underscores the importance of identifying new drug targets and developing new antimicrobial compounds. Lysine and meso-diaminopimelic acid are essential for protein production and bacterial peptidoglycan cell wall remodeling and are synthesized in bacteria by enzymes encoded within dap operon. Therefore dap enzymes may serve as excellent targets for developing a new class of antimicrobial agents. The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) converts N-succinyl-L,L-diaminopimelic acid to L,Ldiaminopimelic acid and succinate. The enzyme is composed of catalytic and dimerization domains, and belongs to the M20 peptidase family. To understand the specific role …