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Directionality Of Point Mutation And 5-Methylcytosine Deamination Rates In The Chimpanzee Genome, Cizhong Jiang, Zhongming Zhao

Psychiatry Publications

Background The pattern of point mutation is important for studying mutational mechanisms, genome evolution, and diseases. Previous studies of mutation direction were largely based on substitution data from a limited number of loci. To date, there is no genome-wide analysis of mutation direction or methylation-dependent transition rates in the chimpanzee or its categorized genomic regions.

Results In this study, we performed a detailed examination of mutation direction in the chimpanzee genome and its categorized genomic regions using 588,918 SNPs whose ancestral alleles could be inferred by mapping them to human genome sequences. The C→T (G→A) changes occurred most frequently in …

The Μ-Opioid Receptor Gene And Smoking Initiation And Nicotine Dependence, Lan Zhang, Kenneth S. Kendler, Xianging Chen

Psychiatry Publications

The gene encoding the mu-opioid receptor (OPRM1) is reported to be associated with a range of substance dependence. Experiments in knockout mice indicate that the mu-opioid receptor may mediate reinforcing effects of nicotine. In humans, opioid antagonist naltrexone may reduce the reinforcing effects of tobacco smoking. Additionally, the OPRM1 gene is located in a region showing linkage to nicotine dependence. The OPRM1 is thus a plausible candidate gene for smoking behavior. To investigate whether OPRM1 contributes to the susceptibility of smoking initiation and nicotine dependence, we genotyped 11 SNPs in the gene for 688 Caucasian subjects of lifetime smokers and …

Knowledge And Awareness Of Congenital Cytomegalovirus Among Women, Jiyeon Jeon, Marcia Victor, Stuart P. Adler, Abigail Arwady, Gail Demmeler, Karen Fowler, Johanna Goldfarb, Harry Keyserling, Mehran Massoudi, Kristin Richards, Stephanie A. S. Staras, Michael J. Cannon

Pediatrics Publications

Background. Congenital cytomegalovirus (CMV) infection is a leading cause of disabilities in children, yet the general public appears to have little awareness of CMV. Methods. Women were surveyed about newborn infections at 7 different geographic locations. Results. Of the 643 women surveyed, 142 (22%) had heard of congenital CMV. Awareness increased with increasing levels of education (P<.0001). Women who had worked as a healthcare professional had a higher prevalence of awareness of CMV than had other women (56% versus16%, P <.0001). Women who were aware of CMV were most likely to have heard about it from a healthcare provider (54%), but most could not correctly identify modes of CMV transmission or prevention. Among common causes of birth defects and childhood illnesses, women's awareness of CMV ranked last. Conclusion. Despite its large public health burden, few women had heard of congenital CMV, and even fewer were aware of prevention strategies.

Optical Susceptibilities Of Supported Indium Tin Oxide Thin Films, Jonathan L. Humphrey, Darius Kuciauskas

Chemistry Publications

The third-order nonlinear optical susceptibility of indium tin oxide (ITO) thin films on glass substrates, χ(3)ITO, was determined in the near-IR spectral region using degenerate four wave mixing (DFWM)spectroscopy with 100fs laser pulses. A DFWM method for measuring thin films on thick substrates was refined for the characterization of films less than 100nm thick and applied to ∼25nm thick ITO films. It was found that χ(3)ITO is purely electronic at 900–1300nm (11000–7700cm−1) and has a value of (2.16±0.18)×10−18m2V−2. Theχ(3)ITO value reaches (3.36±0.28)×10−18m2V−2 at 1500nm (6700cm−1) due to two-photon absorption by free carriers (electrons). Ultrafast electron relaxation was also observed. The …

Reversible Paramagnetism To Ferromagnetism In Transition Metal-Doped Tio2 Nanocrystals Prepared By Microwave Irradiation, Garry Glaspell, Asit B. Panda, M. S. El-Shall

Chemistry Publications

TiO2nanoparticlesdoped with 1%, 5%, and 10% M (M=Co, Fe, and Ni) were prepared by microwave irradiation and characterized using x-ray diffraction, transmission electron microscopy, and magnetometry. The as-prepared samples are found to be paramagnetic at room temperature, with the magnetic susceptibility following the Curie-Weiss law in the investigated range of 2–300K. However, transformation from paramagnetism to room-temperature ferromagnetism (RTFM) was observed by hydrogenating the samples at 400°C. Reheating in air converted the samples back to paramagnetic while rehydrogenating the samples again induced ferromagnetism. It is argued that the reversible RTFM observed is due to interaction between the dopant metal ions …

Cation Occupancy Determination In Manganese Zinc Ferrites Using Fourier Transform Infrared Spectroscopy, M. D. Shultz, E. E. Carpenter, S. A. Morrison, S. Calvin

Chemistry Publications

The magnetic and electric properties of ferrites are influenced by the cation distribution within the crystalline spinel lattice. Methods such as extended x-ray-absorption fine structure(EXAFS) have been used to determine cation occupancies within the crystalline structure of materials such as manganesezincferrite (MZFO); however, it is not practical to be used for daily analysis. Fourier transform infrared (FTIR)spectroscopy is another technique which has the potential to determine cation occupancy while offering speed and convenience. In the literature it has been demonstrated that in ferrite systems FTIR data can be correlated to cation percentages when comparing tetrahedral (Td) and octahedral (Oh) sites. …

Orientational Correlations In Liquid Acetone And Dimethyl Sulfoxide: A Comparative Study, Sylvia E. Mclain, Alan K. Soper, Alenka Luzar

Chemistry Publications

The structure of acetone and dimethyl sulfoxide in the liquid state is investigated using a combination of neutron diffractionmeasurements and empirical potential structure refinement (EPSR) modeling. By extracting the orientational correlations from the EPSR model, the alignment of dipoles in both fluids is identified. At short distances the dipoles or neighboring molecules are found to be in antiparallel configurations, but further out the molecules tend to be aligned predominately as head to tail in the manner of dipolar ordering. The distribution of these orientations in space around a central molecule is strongly influenced by the underlying symmetry of the central …

Glucose Modulates [Ca2+]I Oscillations In Pancreatic Islets Via Ionic And Glycolytic Mechanisms, Craig S. Nunemaker, Richard Bertram, Arthur Sherman, Krasimira Tsaneva-Atanasova, Camille R. Daniel, Leslie S. Satin

Pharmacology and Toxicology Publications

Abstract

Pancreatic islets of Langerhans display complex intracellular calcium changes in response to glucose that include fast (seconds), slow (∼5 min), and mixed fast/slow oscillations; the slow and mixed oscillations are likely responsible for the pulses of plasma insulin observed in vivo. To better understand the mechanisms underlying these diverse patterns, we systematically analyzed the effects of glucose on period, amplitude, and plateau fraction (the fraction of time spent in the active phase) of the various regimes of calcium oscillations. We found that in both fast and slow islets, increasing glucose had limited effects on amplitude and period, but increased …

Magnetic And Mossbauer Spectroscopy Studies Of Nanocrystalline Iron Oxide Aerogels, E. E. Carpenter, J. W. Long, D. R. Rolison, M. S. Logan, K. Pettigrew, R. M. Stroud, L. Theil Kuhn, B. Rosendahl Hasen, S. Mørup

Chemistry Publications

A sol-gel synthesis was used to produce iron oxide aerogels. These nanocrystalline aerogels have a pore-solid structure similar to silica aerogels but are composed entirely of iron oxides. Mössbauer experiments and x-ray diffraction showed that the as-prepared aerogel is an amorphous or poorly crystalline iron oxide, which crystallized as a partially oxidized magnetite during heating in argon. After further heat treatment in air, the nanocrystallites are fully converted to maghemite. The particles are superparamagnetic at high temperatures, but the magnetic properties are strongly influenced by magnetic interactions between the particles at lower temperatures.

A Novel Statistical Method To Estimate The Effective Snp Size In Vertebrate Genomes And Categorized Genomic Regions, Deakwan Seo, Cizhong Jiang, Zhongming Zhao

Psychiatry Publications

Background

The local environment of single nucleotide polymorphisms (SNPs) contains abundant genetic information for the study of mechanisms of mutation, genome evolution, and causes of diseases. Recent studies revealed that neighboring-nucleotide biases on SNPs were strong and the genome-wide bias patterns could be represented by a small subset of the total SNPs. It remains unsolved for the estimation of the effective SNP size, the number of SNPs that are sufficient to represent the bias patterns observed from the whole SNP data.

Results

To estimate the effective SNP size, we developed a novel statistical method, SNPKS, which considers both the statistical …

Accuracy And Consistency Of Radiographic Interpretation Among Clinical Instructors In Conjunction With A Training Program, Sharon K. Lanning, Al M. Best, Henry J. Temple, Philip S. Richards, Alllison Carey, Laurie K. Mccauley

Periodontics Publications

There are inaccuracies and inconsistencies of radiographic interpretation among clinical instructors. The purpose of this investigation was to determine if a training program could improve the accuracy and consistency of instructors’ ratings of bone loss. A total of thirty-five clinical instructors consisting of periodontal faculty (periodontists and general dentists), dental hygiene faculty, and periodontal graduate students viewed projected digitized radiographic images and quantified bone loss for twenty-five teeth into four descriptive categories. Ratings of bone loss were made immediately before (pretest) and after (post-test 1) initiation of the training program and then again three months later (post-test 2). Ratings were …

Menorah Review (No. 64, Winter/Spring, 2006)

Menorah Review

A Poem by Richard E. Sherwin -- An Exceptional Collection -- Author's Reflections -- Hebrew Literature: Translated and Discussed -- Jewish Humor and Jewish Faith -- Reading Writing -- The Uniqueness of American Judaism -- Noteworthy Books

Structure And Bonding Of Au5m (M=Na, Mg, Al, Si, P, And S) Clusters, Chiranjib Majumder, Anil K. Kandalam, Puru Jena

Physics Publications

The atomic and electronic structure of Au5M (M=Na, Mg, Al, Si, P, S, and Au) clusters have been investigated using generalized gradient approximation to the density functional theory. Depending on the nature of interaction with different impurity elements a structural transition from planar to nonplanar configuration has been observed in Au5M. With the exception of S, impurities with p electrons (Al, Si, P) yield nonplanar geometries of Au5M clusters, while those with selectrons (Na, Mg) yield planar geometries. The properties of Au5Scluster are anomalous: The cluster not only has a planar geometry, but also is chemically most stable with the …

Dehydrogenation Mechanism In Catalyst-Activated Mgh2, S. Li, Puru Jena, R. Ahuja

Physics Publications

A small amount of Nb2O5 catalyst is known to substantially improve the desorption thermodynamics and kinetics of MgH2. Using density functional theory in combination with ab initio molecular dynamics simulation, we provide theoretical understanding of the mechanism of dehydrogenation in Nb doped MgH2. We show that the substitution of Nb at the Mg site followed by the clustering of H around Nb is a likely pathway for hydrogen desorption. We also find that dehydrogenation from the vicinity of Mg vacancies is exothermic. However, the vacancies are not likely to play a significant role in hydrogen desorption due to their high …

Effect Of Ti And Metal Vacancies On The Electronic Structure, Stability, And Dehydrogenation Of Na3alh6: Supercell Band-Structure Formalism And Gradient-Corrected Density-Functional Theory, S. Li, Puru Jena

Physics Publications

Electronic and structural properties of sodium-aluminum hexahydride (Na3AlH6) formed during the decomposition reaction of sodium alanate (NaAlH4) and the effects of Ti catalyst are studied using supercell approach and density-functional theory. The preferred site of Ti has been determined by substituting it at both the Na and Al sites and comparing the respective formation energies. The least unfavorable site for Ti is found to be the Al site. To examine the role of Ti substitution on the desorption of hydrogen, the energy cost to remove a H atom from the vicinity of Ti was calculated and compared with that from …

Effect Of Au Coating On The Magnetic And Structural Properties Of Fe Nanoclusters For Use In Biomedical Applications: A Density-Functional Theory Study, Q. Sun, A. K. Kandalam, Q. Wang, Puru Jena, Y. Kawazoe, M. Marquez

Physics Publications

In this paper, we report the first systematic theoretical study of gold-coated iron nanoclusters, aiming at understanding the magnetic properties of this core-shell structure used in biomedical applications. The calculations based on density-functional theory focus on the effect of gold coating on the magnetic and structural properties of iron clusters of various sizes, and the reaction of the bare and coated iron clusters with oxygen. Our results show that the magnetic moment of iron nanocore with gold coating is still significantly higher than that in bulk Fe; the coupling between Fe atoms remained ferromagnetic and is insensitive to the thickness …

Structure And Stability Of Co-N(Pyridine)(M)(-) Clusters: Absence Of Metal Inserted Structures, B. Douglas Edmonds, A. K. Kandalam, S. N. Khanna, X. Li, A. Grubisic, I. Khanna, K. H. Bowen

Physics Publications

A synergistic approach combining the experimental photoelectron spectroscopy and theoretical electronic structure studies is used to probe the geometrical structure and the spin magnetic moment of Con(pyridine)−m clusters. It is predicted that the ground state of Co(pyridine)− is a structure where the Co atom is inserted in a CH bond. However, the insertion is marked by a barrier of 0.33eV that is not overcome under the existing experimental conditions resulting in the formation of a structure where Co occupies a site above the pyridine plane. For Co2(pyridine)−, a ground-state structure is predicted in which the Co2 diametric moiety is inserted …

Hydrogen Storage And The 18-Electron Rule, Boggavarapu Kiran, Anil K. Kandalam, Puru Jena

Physics Publications

We show that the 18-electron rule can be used to design new organometallic systems that can store hydrogen with large gravimetric density. In particular, Ti containing organic molecules such as C4H4, C5H5, and C8H8 can store up to 9wt% hydrogen, which meets the Department of Energy target for the year 2015. More importantly, hydrogen in these materials is stored in molecular form with an average binding energy of about 0.55eV∕H2 molecule, which is ideal for fast kinetics. Using molecular orbitals we have analyzed the maximum number of H2 molecules that can be adsorbed as well as the nature of their …

Gold As Hydrogen: Structural And Electronic Properties And Chemical Bonding In Si3au3+/0/- And Comparisons To Si3h3+/0/-, Boggavarapu Kiran, Xi Li, Hua-Jin Zhai, Lai-Sheng Wang

Physics Publications

A single Au atom has been shown to behave like H in its bonding to Si in several mono- and disilicon gold clusters. In the current work, we investigate the Au∕H analogy in trisilicon gold clusters, Si3Au+∕0∕−3. Photoelectron spectroscopy and density functional calculations are combined to examine the geometric and electronic structure of Si3Au−3. We find that there are three isomers competing for the ground state of Si3Au−3 as is the case for Si3H−3. Extensive structural searches show that the potential energy surfaces of the trisilicon gold clusters (Si3Au−3, Si3Au3, and Si3Au+3) are similar to those of the corresponding silicon …

Hybrid Solar Cells From Water-Soluble Polymers, James T. Mcleskey Jr., Qiquan Qiao

Mechanical and Nuclear Engineering Publications

We report on the use of a water-soluble, light-absorbing polythiophene polymer to fabricate novel photovoltaic devices. The polymer is a water-soluble thiophene known as sodium poly[2-(3-thienyl)-ethoxy-4-butylsulfonate] or PTEBS. The intention is to take advantage of the properties of conjugated polymers (flexible, tunable, and easy to process) and incorporate the additional benefits of water solubility (easily controlled evaporation rates and environmentally friendly). The PTEBS polythiophene has shown significant photovoltaic response and has been found to be effective for making solar cells. To date, solar cells in three different configurations have been produced: titanium dioxide (TiO2) bilayer cells, TiO2 bulk heterojunction solar …

Strong Suppression Of The Yellow Luminescence In C-Doped Gan In Air Ambient, Michael A. Reshchikov

Physics Publications

The authors observed a drastic reduction of the yellow luminescence (YL) intensity in carbon-doped semi-insulating GaN in air or oxygen ambient as compared to the intensity in vacuum. The YL intensity dropped about 300 times while the exciton emission remained almost unchanged. The authors assume that the donor-acceptor-pair transitions involving a gallium vacancy complex in a thin near-surface region cause the strong YL. Oxygen molecules or ions induce the surface states acting as a very efficient channel of nonradiative recombination. The results indicate that carbon may not be involved in the acceptor responsible for the YL band in GaN:C.

Midinfrared Intersubband Absorption In Znxcd1−Xse/Znx′Cdy′Mg1−X′−Y′Se Multiple Quantum Well Structures, H. Lu, A. Shen, M. C. Tamargo, C. Y. Song, H. C. Liu, S. K. Zhang, R. R. Alfano, M. Muñoz

Physics Publications

The authors report the observation of intersubband absorption in ZnxCd(1−x)Se/Znx′Cdy′Mg(1−x′−y′)Semultiple quantum wells. Lattice-matched samples were grown by molecular beam epitaxy on InP (001) substrates. Photoluminescence measurements indicate that the samples have excellent material quality. The peak absorption wavelengths measured by Fourier transform infrared spectroscopy are 3.99 and 5.35μm for two samples with ZnxCd(1−x)Se well widths of 28 and 42Å, respectively. These values fall within the 3–5μm wavelength range, which is of interest for midinfrared intersubband devices, such as quantum cascade lasers and quantum well infrared photodetectors. Their experimental results fit well with theoretical predictions based on the envelope function approximation. …

Determination Of Acceptor Concentration In Gan From Photoluminescence, Michael A. Reshchikov

Physics Publications

The concentration of the acceptor responsible for the yellow luminescence (YL) band at about 2.2eV in GaN is determined from photoluminescence. The YL band intensity increases linearly with excitation power density and partially saturates above some critical value. The dependence is quantitatively described within a phenomenological model accounting for recombination statistics in GaN layer and saturation of acceptors with photogenerated holes. The incomplete saturation of the YL intensity at high excitation intensities is explained by gradual saturation of acceptors at different distances from the sample surface. The identity of deep and shallow acceptors in GaN is discussed.

Lactate Versus Non-Lactate Metabolic Acidosis: A Retrospective Outcome Evaluation Of Critically Ill Patients, Kyle J. Gunnerson, Melissa Saul, Shui He, John A. Kellum

Anesthesiology Publications

Introduction

Acid–base abnormalities are common in the intensive care unit (ICU). Differences in outcome exist between respiratory and metabolic acidosis in similar pH ranges. Some forms of metabolic acidosis (for example, lactate) seem to have worse outcomes than others (for example, chloride). The relative incidence of each type of disorder is unknown. We therefore designed this study to determine the nature and clinical significance of metabolic acidosis in critically ill patients.

Methods

An observational, cohort study of critically ill patients was performed in a tertiary care hospital. Critically ill patients were selected on the clinical suspicion of the presence of …

Digital Equity In Education: A Multilevel Examination Of Differences In And Relationships Between Computer Access, Computer Use And State-Level Technology Policies, Jonathan D. Becker

Educational Leadership Publications

Using data from the National Assessment of Educational Progress (NAEP) state assessment and a survey of state-level technology policies, this study examined digital equity in education as a multilevel organizational phenomenon with data from 70,382 students in 3,479 schools and 40 states. Students in rural schools or schools with higher percentages of African American students were likely to have less access to computers. With respect to computer use, girls and students eligible for free or reduced-price lunch were more likely to use computers more frequently when computers are available in the classroom. With respect to relationships between computer access and …

Survival Analysis Of Complete Veneer Crowns Vs. Multisurface Restorations: A Dental School Patient Population, Charles E. Janus, John W. Unger, Al M. Best

Prosthodontics Publications

The purpose of this study was to compare the longevity of crowns versus large multisurface restorations in posterior teeth. The investigation used the treatment database at Virginia Commonwealth University School of Dentistry. The inclusion criteria for the final data set used for analysis were: only one restored tooth per patient, premolars with three or more restored surfaces, molars with four or more restored surfaces, molars and premolars restored with complete veneer metal crowns, or crowns veneered with metal and porcelain. The Kaplan-Meier approach was used to visualize the survival curves, and the Cox proportional hazards model was used for analysis …

Normal And Inverse Spin-Valve Effect In Organic Semiconductor Nanowires And The Background Monotonic Magnetoresistance, Sandipan Pramanik, Supriyo Bandyopadhyay, Kalyan Garre, Marc Cahay

Electrical and Computer Engineering Publications

We have observed both peaks and troughs in the magnetoresistance of organic nanowires consisting of three layers—cobalt, 8-hydroxy-quinolinolato aluminum (Alq3), and nickel. They always occur between the coercive fields of the ferromagnetic layers, and we attribute them to the normal and inverse spin-valve effect. The latter is caused by resonant tunneling through localized impurity states in the organic material. Peaks are always found to be accompanied by a positive monotonic background magnetoresistance, while troughs are accompanied by a negative monotonic background magnetoresistance. This curious correlation suggests that the background magnetoresistance, whose origin has hitherto remained unexplained, is probably caused by …

Surface Band Bending Of A-Plane Gan Studied By Scanning Kelvin Probe Microscopy, S. A. Chevtchenko, X. Ni, Q. Fan, A. A. Baski, Hadis Morkoç

Electrical and Computer Engineering Publications

We report the value of surface band bending for undoped, a-plane GaN layers grown on r-plane sapphire by metalorganic vapor phase epitaxy. The surface potential was measured directly by ambient scanning Kelvin probe microscopy. The upward surface band bending of GaN films grown in the [112¯0] direction was found to be 1.1±0.1V. Because polarization effects are not present on a-plane GaN, we attribute such band bending to the presence of charged surface states. We have modeled the surface band bending assuming a localized level of surface states in the band gap on the surface. It should be noted that the …

Persistence Of Vision: The Value Of Invention In Independent Art Animation, Pamela Turner

Kinetic Imaging Publications and Presentations

The focus of this investigation is in the realm of animation that straddles the ever-shrinking gulf between a screening and an exhibition, the theater and the art gallery. There is a subtle maturity and movement in the animation art world that not only continues but also extends the often-overlooked legacy of independent animation while engaging the conceptual dialogue of contemporary art. This tradition of an art aesthetic is passed from the early inventors who fashioned the necessary tools and images. The myriads of techniques and concepts evidenced throughout this history inform the current practitioner, just as digital technology and the …

Organic Anion And Cation Transporter Expression And Function During Embryonic Kidney Development And In Organ Culture Model Systems, Douglas H. Sweet, Satish A. Eraly, Kevin T. Bush, Sanjay K. Nigam

Pharmaceutics Publications

Background

Organic anion and cation transporters (OATs, OCTs and OCTNs) mediate the proximal tubular secretion of numerous clinically important compounds, including various commonly prescribed pharmaceuticals. Here, we examine the ontogeny of these transporters in rat embryonic kidney in detail, both in vivo and in two in vitro organ culture models of kidney development, whole embryonic kidney (WEK) culture and culture of induced metanephric mesenchyme (MM).

Methods

We used QPCR to determine expression levels of transporter genes in rat embryonic kidneys on each day of gestation from ed13 to ed18, in induced and un-induced MM, and on each day of one …