Digital Commons Network^™

A New View Of Ridge Segmentation And Near-Axis Volcanism At The East Pacific Rise, 8˚–12˚N, From Em300 Multibeam Bathymetry, Scott M. White, Rachel M. Haymon, S M. Carbotte

Faculty Publications

New, high-resolution bathymetry for the East Pacific Rise between 8˚N and 12˚N was collected over a6 km wide swath centered on the ridge axis using the 30 kHz Simrad EM300 multibeam system. Thecoverage area corresponds latitudinally to the designated Ridge2000 Integrated Studies Site (ISS) for fastspreading ridges. The EM300 data, gridded at 30 m latitude by 50 m longitude, represent a greater than 4Ximprovement in horizontal resolution over previously available multibeam data and a 2X improvement indepth resolution. The new bathymetry was used to update the locations and hierarchy of ridge offsets forthis area. Among the many applications for this …

Indeterminacy And Society By Russell Hardin, Daniel R. Sabia

Faculty Publications

No abstract provided.

A Novel Account Of Scientific Anomaly: Help For The Dispute Over Low-Dose Biochemical Effects, Kevin C. Elliott

Faculty Publications

The biological effects of low doses of toxic and carcinogenic chemicals are currently a matter of significant scientific controversy. This paper argues that philosophers of science can contribute to alleviating this controversy by examining it with the aid of a novel account of scientific anomaly. Specifically, analysis of contemporary research on chemical hormesis (i.e.. alleged beneficial biological effects produced by low doses of substances that are harmful at higher doses) suggests that scientists may initially describe anomalous phenomena in terms of multiple distinct '"characterizations," each
of which is compatible with current empirical evidence. By focusing attention on this feature of …

Theory Of Cavity-Polariton Self-Trapping And Optical Strain In Polymer Chains, M. V. Katkov, Yuriy V. Pershin Dr, C. Piermarocchi

Faculty Publications

We consider a semiconductor polymer chain coupled to a single electromagnetic mode in a cavity. The excitations of the chain have a mixed exciton-photon character and are described as polaritons. Polaritons are coupled to the lattice by the deformation potential interaction and can propagate in the chain. We find that the presence of optical excitation in the polymer induces strain on the lattice. We use a BCS variational wave function to calculate the chemical potential of the polaritons as a function of their density. We analyze first the case of a short chain with only two unit cells in order …

Objectively Measured Physical Activity In Sixth-Grade Girls, Russell R. Pate, June Stevens, Charlotte Pratt, James F. Sallis, Kathryn H. Schmitz, Larry S. Webber, Gregory J. Welk, Deborah Rohm Young

Faculty Publications

Objectives - To describe the objectively-measured physical activity (PA) characteristics of a diverse sample of 6^th grade girls to examine influences on PA, and to report compliance with PA guidelines.

Design - Cross-sectional study.

Setting - Six locations across the United States.

Participants - 1578 6^th grade girls. Actigraph accelerometers were worn for 7 days, and data for 6 days were included in the analyses.

Main exposure - Race/ethnicity, free-or-reduced price lunch (FRPL), and geographic region.

Main outcome measure - Six operational definitions of adequate activity (60 min or 30 min of daily MVPA at or above 4.6, …

Linking Bacterioplankton Community Structures To Environmental State Variables And Phytoplankton Assemblages In Two South Carolina Salt Marsh Estuaries, Wes Johnson, Alan J. Lewitus, Madilyn Fletcher

Faculty Publications

Microorganisms are among the most important organisms to the ecology of salt marsh estuaries; however, fundamental questions regarding their distribution, environmental controls, and interactions with phytoplankton remain unanswered. We used denaturing gradient gel electrophoresis (DGGE) of bacterial rRNA genes and high performance liquid chromatography (HPLC) of phytoplankton photopigments to characterize planktonic communities from the Ashepoo, Combahee, and Edisto (ACE) Basin and North Inlet (NI) estuaries on the South Carolina coast, USA. Multivariate comparisons of the planktonic community profiles revealed that the 2 estuaries supported distinct bacterial communities. Furthermore, bacterial communities in both systems were partitioned into separate particle-associated (PA) and …

Tetrakis(N-Ethyl-9-Oxo-4-Azonia-5-Aza-9h-Fluorene) Tetra-Μ3-Iodo-Hexa-Μ2-Iodo-Dodecaiodohexabismuthate, Meredith A. Tershany, Andrea M. Goforth, Mark D. Smith, Leroy Peterson Jr., Hans-Conrad Zur Loye

Faculty Publications

The new iodobismuthate compound (C₁₃H₁₁N₂O)₄[Bi₆I₂₂] has been synthesized solvothermally by reacting BiI₃, Zn(NO₃)₂·6H₂O and 4,5-diazafluoren-9-one in a water/ethanol solvent mixture. The asymmetric unit of the compound contains two independent [N-ethyl-4,5-dafo]⁺ cations and one-half of a centrosymmetric [Bi₆I₂₂]^4- anion. The average terminal Bi-I, Bi-₂-I and Bi-₃-I bond lengths in the anion are 2.8923 (2), 3.1403 (2) and 3.3022 (2) Å, respectively.

Subtidal Inner Shelf Currents Off Cartagena De Indias, Caribbean Coast Of Colombia, Mauro Maza, George Voulgaris, Bulusu Subrahmanyam

Faculty Publications

Seasonal trends in inner shelf subtidal circulation off the coast of Cartagena de Indias, Colombia, are examined through the analysis of current profiles, hydrographic, meteorological and satellite data collected from 1999 to 2002. During the dry season (December–April) the water column is well-mixed and along-shelf currents flow southwestward following the steady trade winds. In the rainy season (May –November) the water column experiences continuous events of stratification and the along-shelf currents flow northeastward, opposing the weak southwestward winds. In the dry season the along shelfcirculation is mostly driven by wind forcing, while in the rainy season, the circulation is set …

Dynamic Modeling And Statistical Analysis Of Event Times, Edsel A. Pena

Faculty Publications

This review article provides an overview of recent work in the modeling and analysis of recurrent events arising in engineering, reliability, public health, biomedicine and other areas. Recurrent event modeling possesses unique facets making it different and more difficult to handle than single event settings. For instance, the impact of an increasing number of event occurrences needs to be taken into account, the effects of covariates should be considered, potential association among the interevent times within a unit cannot be ignored, and the effects of performed interventions after each event occurrence need to be factored in. A recent general class …

The Role Of Training Variables In Effective Dissemination Of Evidence-Based Parenting Interventions, Alexandra C. Seng, Ronald J. Prinz, Matthew R. Sanders

Faculty Publications

From a public health perspective, mental health in parents and children can be promoted through population-based dissemination of parenting and family support interventions. However, it is critical that service providers who are acquiring evidence-based parenting interventions complete the training regimen to optimize dissemination and impact. This article examines training completion and its relationship to individual service provider characteristics, barriers to program use and subsequent implementation of an evidence-based program, the Triple P - Positive Parenting Program. In this study, 83.7% of the service providers completed the two-part training. Individual-level variables did not predict training completion. Service providers from diverse backgrounds …

Arthur Hugh Clough And Florence Nightingale: A Relationship Reexamined, Patrick G. Scott

Faculty Publications

Discusses the relationship between the Victorian poet Arthur Hugh Clough and his cousin-by-marriage the nursing reformer Florence Nightingale, using manuscript and other evidence to counter the varicature offered by Lytton Strachey in his influential book Eminent Victorians.

African-American Mitochondrial Dnas Often Match Mtdnas Found In Multiple African Ethnic Groups, Bert Ely, Jamie Lee Wilson, Fatimah Jackson, Bruce A. Jackson

Faculty Publications

Mitochondrial DNA (mtDNA) haplotypes have become popular tools for tracing maternal ancestry, and several companies offer this service to the general public. Numerous studies have demonstrated that human mtDNA haplotypes can be used with confidence to identify the continent where the haplotype originated. Ideally, mtDNA haplotypes could also be used to identify a particular country or ethnic group from which the maternal ancestor emanated. However, the geographic distribution of mtDNA haplotypes is greatly influenced by the movement of both individuals and population groups. Consequently, common mtDNA haplotypes are shared among multiple ethnic groups. We have studied the distribution of mtDNA …

The Voting Rights Act Of 1965: A Selected Annotated Bibliography, Terrye Conroy

Faculty Publications

Several remedial or "special" provisions of the Voting Rights Act of 1965, which were enacted as temporary measures and were set to expire in August 2007 if not reauthorized by Congress, were recently extended for another twenty-five years. Ms. Conroy offers a selected bibliography of resources to introduce researchers to the issues involved in the debate over the Act's reauthorization and its future implementation.

Fabrication And Characterization Of Poly(Propylene Fumarate) Scaffolds With Controlled Pore Structures Using 3-Dimensional Printing And Injection Molding, Kee-Won Lee, Shanfeng Wang, Lichun Lu, Esmaiel Jabbari, Bradford L. Currier, Michael J. Yaszemski

Faculty Publications

Poly(propylene fumarate) (PPF) is an injectable, biodegradable polymer that has been used for fabricating preformed scaffolds in tissue engineering applications because of in situ crosslinking characteristics. Aiming for understanding the effects of pore structure parameters on bone tissue ingrowth, 3-dimensional (3D) PPF scaffolds with controlled pore architecture have been produced in this study from computer-aided design (CAD) models. We have created original scaffold models with 3 pore sizes (300, 600, and 900 µm) and randomly closed 0%, 10%, 20%, or 30% of total pores from the original models in 3 planes. PPF scaffolds were fabricated by a series steps involving …

Physical Activities In Adolescent Girls: Variability In Energy Expenditure, Karin A. Pfeiffer, Kathryn H. Schmitz, Robert G. Mcmurray, Margarita S. Treuth, David M. Murray, Russell R. Pate

Faculty Publications

Background - Understanding interindividual variability of energy expended in common activities is important for determining precise estimates of energy expenditure in surveillance studies and clinical trials. The purpose of this study was to describe the variability in energy expenditure for selected physical activities among adolescent girls.

Methods - Seventy-four adolescent girls (aged 13 to 14 years) participated in this cross-sectional investigation. Data were collected in 2001 and analyzed in 2004. Energy expenditure was measured by indirect calorimetry for ten activities and during a submaximal cycle ergometer test, which was used to estimate cardiorespiratory fitness. Variability in energy expended for the …

A Nd Isotopic Study Of Southern Sourced Waters And Indonesian Throughflow At Intermediate Depths In The Cenozoic Indian Ocean, Ellen E. Martin, Howie Scher

Faculty Publications

We present Nd isotopic data for fossil fish teeth recovered from the past 40 m.y. at ODP Site 757, currentlylocated at 1650m water depth on the Ninetyeast Ridge in the Indian Ocean. Although Site 757 sits in a regionstrongly influenced by weathering inputs from the Himalayas and volcanic inputs from the Indonesian arc, the pattern of Nd isotopic variations does not appear to respond to these potential sources of Nd. Instead, secular variations correlate to changes in the composition of intermediate to deep water masses bathing thesite and circulation patterns in the Indian Ocean. From ~40 to 10 Ma, eNd …

Absorption Properties Of A Porous Organic Crystalline Apohost Formed By A Self-Assembled Bis-Urea Macrocycle, Mahender B. Dewal, Michael W. Lufaso, Andrew D. Hughes, Stevan A. Samuel, Perry J. Pellechia, Linda S. Shimizu

Faculty Publications

We report herein the characterization and binding properties of a microporous crystalline host formed by the self assembly of a bis-urea macrocycle 1. Bis-urea macrocycle 1 has been designed to crystallize into stacked hollow columns. The self-assembly process is guided primarily by hydrogen bonding and aromatic stacking interactions that yield crystals of filled host 1âacetic acid (AcOH). The AcOH guests are bound in the cylindrical cavities of the crystal. The guest AcOH can be removed by heating to form a stable crystalline apohost 1. Apohost 1 displays a type I gas adsorption isotherm with CO₂ that is consistent with …

The Macroeconomic News Cycle And Uncertainty Resolution, Arjun Chatrath, Rohan Christie-David, William T. Moore

Faculty Publications

We examine the behavior of return volatility and trading at 5-minute intervals in the treasury bond futures market in the context of the monthly macroeconomic news cycle. We advance and confirm the hypothesis that volatility and trading activity are higher in the first half of the month. The data indicate that these patterns arise from at least two sources: (1) a higher level of uncertainty regarding the value of news in announcements in the first half of the month, and (2) improvement in efficiency of macroeconomic forecasts from the first to the second half of the month.

A New Class Of Miniature Embedded Inverted-F Antennas (Ifas) For 2.4 Ghz Wlan Application, Mohammed Z. Azad, Mohammod Ali

Faculty Publications

A new class of miniature printed embedded inverted-F antennas are proposed for operation in the 2.4-2.485 GHz wireless local-area network band. One of the proposed antennas on FR4 substrate (dielectric constant = 4.4) measures 9.2 mm by 4.1 mm and has a bandwidth of 3.5%. The peak gain of this antenna is 1.4 dBi. An overall size reduction of 70% is achieved compared to a conventional inverted-F antenna. Effects of dielectric loss tangent and material conductivity on the bandwidth and efficiency of these antennas are also investigated. Finally, two embedded antenna elements are analyzed to demonstrate the feasibility for a …

The 1.6-Kv Algan/Gan Hfets, N. Tipirneni, Alexei Koudymov, V. Adivarahan, Jinwei Yang, Grigory Simin, Asif Khan

Faculty Publications

The breakdown voltages in unpassivated nonfield-plated AlGan/GaN HFETs on sapphire substrates were studied. These studies reveal that the breakdown is limited by the surface flashover rather than by the AlGan/GaN channel. after elimination of the surface flashover in air, the breakdown voltage scaled linearly with the gate-drain spacing reaching 1.6 kV at 20 mu m. The corresponding static ON-resistance was as low as 3.4 m Omega(.)cm(2). This translates to a power device figure-of-merit V-BR(2)/R-ON = 7.5 x 10(8) V-2 . n(-1) cm(-2), which, to date, is among the best reported values for an AlGan/GaN HFET.

Promoting Physical Activity In Children And Youth: A Leadership Role For Schools: A Scientific Statement From The American Heart Association Council On Nutrition, Physical Activity, And Metabolism (Physical Activity Committee) In Collaboration With The Councils On Cardiovascular Disease In The Young And Cardiovascular Nursing, Russell R. Pate, Michael G. Davis, Thomas N. Robinson, Elaine J. Stone, Thomas L. Mckenzie, Judith C. Young

Faculty Publications

No abstract provided.

Tetrakis[2-(2-Pyridyl)Pyridinium] Tetra-Μ3-Iodo-Hexa-Μ2-Iodo-Dodecaiodohexabismuthate And Bis[Tris(2,2'-Bipyridine)Ruthenium(Ii)] Di-Μ4-Iodo-Octa-Μ2-Iodo-Dodecaiodohexabismuthate, Andrea M. Goforth, Meredith A. Tershansy, Mark D. Smith, Leroy Peterson Jr., Hans-Conrad Zur Loye

Faculty Publications

Crystals of the title compounds were grown solvothermally in an ethanol-water solvent mixture using ruthenium triiodide, 2,2'-bipyridine and bismuth triiodide as starting materials. Tetrakis[2-(2-pyridyl)pyridinium] tetra-₃-iodo-hexa-₂-iodo-dodecaiodohexabismuthate, (C₁₀H₉N₂)₄[Bi₆I₂₂], crystallizes in the triclinic space group P and is the major reaction product. The asymmetric unit of this compound consists of half a centrosymmetric [Bi₆I₂₂]^4- anion and two independent 2,2'-bipyridinium cations. The minor product of the reaction is bis[tris(2,2'-bipyridine)ruthenium(II)] di-₄-iodo-octa-₂-iodo-dodecaiodohexabismuthate, [Ru(C₁₀H₈N₂)₃] …

Positive Current Correlations Associated With Super-Poissonian Shot Noise, Yuanzhen Chen, Richard A. Webb

Faculty Publications

We report on shot noise cross spectrum measurements in a beam splitter configuration. Electrons tunneling through potential barriers are incident on a beam splitter and scattered into two separate channels. Such a partition process introduces correlations between the fluctuations of the two currents. Our work has confirmed that the generally expected negative correlations resulted from sub-Poissonian electron sources. More interestingly, positive cross correlations associated with barriers exhibiting super-Poissonian shot noise have also been observed. We have found that both positive and negative correlations can be related to the noise properties of the electron source.

The Place, Range, And Taxonomy Of Control And Raising, Willaim D. Davies, Stanley William Dubinsky

Faculty Publications

No abstract provided.

The Clinical Research Forum And Association Of American Physicians Disagree With Criticism Of The Nih Roadmap, William Crowley Jr, John Courtney, Larry Jameson, Herbert Pardes, Jay Moskowitz, Eugene Orringer, Arthur Rubenstein, Alastair Wood, Richard Rettig, Dennis Ausiello, David Brenner, Francis Collins, Jack Elias, Warner Greene, Ralph Horowitz, Larry Jameson, Elliott Kieff, Craig Thompson, Judith Swain

Faculty Publications

No abstract provided.

A Compact Digitally Controlled Fuel Cell/Battery Hybrid Power Source, Zhenhua Jiang, Roger A. Dougal

Faculty Publications

A compact digitally controlled fuel cell/battery hybrid power source is presented in this paper. The hybrid power source composed of fuel cells and batteries provides a much higher peak power than each component alone while preserving high energy density, which is important and desirable for many modern electronic devices, through an appropriately controlled dc/dc power converter that handles the power flow shared by the fuel cell and the battery. Rather than being controlled to serve only as a voltage or current regulator, the power converter is regulated to balance the power flow to satisfy the load requirements while ensuring the …

Self-Assembled Composite Nano-/Micronecklaces With Sio2 Beads In Boron Strings, Hai Ni, Xiaodong Li

Faculty Publications

Nano-/micronecklaces with SiO₂ beads in boron strings were synthesized by simply sublimating the desired powders in a sealed quartz tube at high temperature. The boron strings have a rectangular cross section with width varying from 80to1000nm while the SiO₂ beads bear either spindle or spherical shape with a size ranging from 100nmto5μm. The spacing between the SiO₂ beads is uniform in each boron string. Both the boron strings and the SiO₂ beads are amorphous and free of defects. The supersaturated vapors of silicon and oxygen induced the SiO₂ bead formation.

Iii-Nitride Transistors With Capacitively Coupled Contacts, Grigory Simin, Z.-J. Yang, A. Koudymov, V. Adivarahan, M. Asif Khan

Faculty Publications

AlGaN∕GaNheterostructure field-effect transistor design using capacitively coupled contacts (C³HFET) is presented. Insulated-gate [C³ metal-oxide-semiconductor HFET(C³MOSHFET)] has also been realized. The capacitively coupled source, gate, and drain of C3 device do not require annealedOhmic contacts and can be fabricated using gate alignment-free technology. For typical AlGaN∕GaNheterostructures, the equivalent contact resistance of C³ transistors is below 0.6Ωmm. In rf-control applications, the C³HFET and especially the C³MOSHFET have much higher operating rf powers as compared to HFETs.C³ design is instrumental for studying the two-dimensional electron gas transport in other wide band gap …

Ecological Fitting As A Determinant Of The Community Structure Of Platyhelminth Parasites Of Anurans, Daniel R. Brooks, Virginia León-Règagnon, Deborah Mclennan, Derek Zelmer

Faculty Publications

Host–parasite associations are assumed to be ecologically specialized, tightly coevolved systems driven by mutual modification in which host switching is a rare phenomenon. Ecological fitting, however, increases the probability of host switching, creating incongruences between host and parasite phylogenies, when (1) specialization on a particular host resource is a shared characteristic of distantly related parasites, and (2) the resource being tracked by the parasite is widespread among many host species. We investigated the effect of ecological fitting on structuring the platyhelminth communities of anurans from a temperate forest and grassland in the United States and tropical dry and wet forests …

Aintegumenta Contributes To Organ Polarity And Regulates Growth Of Lateral Organs In Combination With Yabby Genes, Staci Nole-Wilson, Beth A. Krizek

Faculty Publications

Lateral organs in flowering plants display polarity along their adaxial-abaxial axis with distinct cell types forming at different positions along this axis. Members of three classes of transcription factors in Arabidopsis (Arabidopsis thaliana; the Class III homeodomain/leucine zipper [HD-ZIP] proteins, KANADI proteins, and YABBY proteins) are expressed in either the adaxial or abaxial domain of organ primordia where they confer these respective identities. Little is known about the factors that act upstream of these polarity-determining genes to regulate their expression. We have investigated the relationship between AINTEGUMENTA (ANT), a gene that promotes initiation and growth of lateral …