Physical Sciences and Mathematics Commons^™

Mesophase Separation And Probe Dynamics In Protein–Polyelectrolyte Coacervates, A. Basak Kayitmazer, Himadri B. Bohidar, Kevin W. Mattison, Arijit Bose, Jayashri Sarkar, Akihito Hashidzume, Paul S. Russo, Werner Jaeger, Paul Dubin

Paul Dubin

Protein–polyelectrolyte coacervates are self-assembling macroscopically monophasic biomacromolecular fluids whose unique properties arise from transient heterogeneities. The structures of coacervates formed at different conditions of pH and ionic strength from poly(dimethyldiallylammonium chloride) and bovine serum albumin (BSA), were probed using fluorescence recovery after photobleaching. Measurements of self-diffusion in coacervates were carried out using fluorescein-tagged BSA, and similarly tagged Ficoll, a non-interacting branched polysaccharide with the same size as BSA. The results are best explained by temporal and spatial heterogeneities, also inferred from static light scattering and cryo-TEM, which indicate heterogeneous scattering centers of several hundred nm. Taken together with previous dynamic …

Analysis Of The Longitudinal Low-Order Mode Beam Dynamics In Pep-Ii Rings At High Current Beams, Themis Mastorides, C. Rivetta, J.D. Fox, D. Teytelman, D. Van Winkle

Physics

PEP-II plans to achieve the final goal in luminosity will require an increase of the beam currents to 4 A for LER and 2.2 A for HER. These magnitudes are challenging in part because they will push the longitudinal low-order mode (LOM) beam stability and the station stability to the limit. To analyze the behavior of both rings at high currents and to understand the limits in the longitudinal feedback systems, a simulation tool has been developed at SLAC. This tool is based on a reduced model of the longitudinal LOM dynamics of the beam interacting with the effective impedance …

Selecting Rf Amplifiers For Impedance Controlled Llrf Systems - Nonlinear Effects And System Implications, John D. Fox, Themis Mastorides, Claudio Hector Rivetta, Daniel Van Winkle

Physics

Several high-current accelerators use feedback techniques in the accelerating RF systems to control the impedances seen by the circulating beam. [1, 2] These Direct and Comb Loop architectures put the high power klystron and LLRF signal processing components inside feedback loops, and the ultimate behavior of the systems depends on the individual sub-component properties. Imperfections and non-idealities in the signal processing leads to reduced effectiveness in the impedance controlled loops. In the PEP-II LLRF systems non-linear effects have been shown to reduce the achievable beam currents, increase low-mode longitudinal growth rates and reduce the margins and stability of the LLRF …

Cameras, Coyotes, And The Assumption Of Equal Detectability, Eveline Se Quin Larrucea, Peter F. Brussard, Michael M. Jaegar, Reginald H. Barrett

United States Department of Agriculture Wildlife Services: Staff Publications

Remote cameras are an increasingly important tool in management and wildlife studies. However, we often do not know if they provide an unbiased sample of populations. Using a marked, radio-collared population of coyotes (Canis latrans) of known social status, we evaluated the influence of temporal (daily and seasonal) and spatial (distance between units, habitat, and proximity to human structures) factors on vulnerability to photo-captures. During 8 unbaited camera sessions of 6 weeks each, we obtained 158 coyote photographs at a photo-capture success rate of 1.6%. We were able to identify not only marked individuals, but also a number …

Fence-Line Contact Between Wild And Farmed White-Tailed Deer In Michigan: Potential For Disease Transmission, Kurt C. Vercauteren, Michael J. Lavelle, Nathan W. Seward, Justin W. Fischer, Gregory E. Phillips

United States Department of Agriculture Wildlife Services: Staff Publications

Interactions between wild and farmed white-tailed deer (Odocoileus virginianus) along perimeter fences may play a role in the transmission of diseases like bovine tuberculosis and chronic wasting disease. However, no study has evaluated direct contact between wild and farmed deer through fences. We used animal-activated cameras to estimate rates of interaction between wild and farmed deer at 6 high-fenced commercial white-tailed deer farms in Michigan, USA, during October 2003 to January 2005. We recorded only 2 direct, naso-oral contacts between wild and farmed deer during >77,000 hours of camera monitoring. We documented little direct contact between wild and …

Fence-Line Contact Between Wild And Farmed Cervids In Colorado: Potential For Disease Transmission, Kurt C. Vercauteren, Michael J. Lavelle, Nathan W. Seward, Justin W. Fischer, Gregory E. Phillips

United States Department of Agriculture Wildlife Services: Staff Publications

Direct and indirect contact between wild and farmed cervids along perimeter fences may play a role in transmission of diseases like chronic wasting disease (CWD), but no studies have quantified such interactions. At 9 high-fenced commercial elk (Cervus elaphus) farms in Colorado, USA, during October 2003 to January 2005, we used animal-activated video to estimate rates of fence-line use by wild cervids, rates of direct contact between farmed and wild cervids, and probability of direct contact when wild cervids were present. We recorded 8-foldmore wild elk per unit time than mule deer (Odocoileus hemionus) at fence …

Coyotes As Sentinels For Monitoring Bovine Tuberculosis Prevalence In White-Tailed Deer, Todd C. Atwood, Kurt C. Vercauteren, Thomas J. Deliberto, Holly J. Smith, Justin S. Stevenson

United States Department of Agriculture Wildlife Services: Staff Publications

Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is endemic in free-ranging white-tailed deer (Odocoileus virginianus) in 5 counties (Alcona, Alpena, Montmorency, Oscoda, and Presque Isle) in the northeastern Lower Peninsula of Michigan, USA. The presence of a wildlife reservoir of tuberculosis in Michigan and the incidence of bTB in cattle (Bos taurus) resulted in Michigan losing its bTB accredited-free status. Subsequent wildlife surveillance programs identified relatively high disease prevalence in coyotes (Canis latrans), generating interest in their potential to serve as a sentinel species to detect bTB prevalence in white-tailed deer. …

Caffeine Formulation For Avian Repellency, Scott J. Werner, John L. Cummings, Shelagh K. Tupper, Jerome C. Hurley, Randal S. Stahl, Thomas M. Primus

United States Department of Agriculture Wildlife Services: Staff Publications

Nonlethal management alternatives are needed to reduce avian depredation of agricultural crops. Caffeine has promise as an effective, economical, and environmentally safe avian repellent, yet formulation improvements are needed for field applications. We included sodium benzoate in subsequent formulations to enhance the solubility of caffeine. Red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated rice and rice treated with 250 ppm or 10,000 ppm caffeine and sodium benzoate in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 250 ppm, 1,000 ppm, 2,500 ppm, 5,000 ppm, 10,000 ppm, or 20,000 ppm caffeine and sodium benzoate. Relative …

Potentiometric And Relaxometric Properties Of A Gadolinium-Based Mri Contrast Agent For Sensing Tissue Ph, Ferenc K. Kálmán, Mark Woods, Peter Caravan, Paul Jurek, Marga Spiller, Gyula Tircso, Róbert Király, Ernő Brücher, A. Dean Sherry

Chemistry Faculty Publications and Presentations

The pH-sensitive contrast agent, GdDOTA-4AmP (Gd1) has been successfully used to map tissue pH by MRI. Further studies now demonstrate that two distinct chemical forms of the complex can be prepared depending upon the pH at which Gd³⁺ is mixed with ligand 1. The desired pH-sensitive form of this complex, referred to here as a Type II complex, is obtained as the exclusive product only when the complexation reaction is performed above pH 8. At lower pH values, a second complex is formed that, by analogy with an intermediate formed during the preparation of GdDOTA, we tentatively assign …

Towards Lattice Simulation Of The Gauge Theory Duals To Black Holes And Hot Strings, Simon Catterall, Toby Wiseman

Physics - All Scholarship

A generalization of the AdS/CFT conjecture postulates a duality between IIA string theory and 16 supercharge Yang-Mills quantum mechanics in the large N 't Hooft limit. At low temperatures string theory describes black holes, whose thermodynamics may hence be studied using the dual quantum mechanics. This quantum mechanics is strongly coupled which motivates the use of lattice techniques. We argue that, contrary to expectation, the theory when discretized naively will nevertheless recover continuum supersymmetry as the lattice spacing is sent to zero. We test these ideas by studying the 4 supercharge version of this Yang-Mills quantum mechanics in the 't …

Experimental Determination Of Salinity, Temperature, Growth, And Metabolic Effects On Shell Isotope Chemistry Of Mytilus Edulis Collected From Maine And Greenland, Alan D. Wanamaker Jr., Karl J. Kreutz, Harold W. Borns Jr., Douglas S. Introne, Scott Feindel, Svend Funder, Paul D. Rawson, Bruce J. Barber

Earth Science Faculty Scholarship

To study the effects of temperature, salinity, and life processes (growth rates, size, metabolic effects, and physiological/ genetic effects) on newly precipitated bivalve carbonate, we quantified shell isotopic chemistry of adult and juvenile animals of the intertidal bivalve Mytilus edulis (Blue mussel) collected alive from western Greenland and the central Gulf of Maine and cultured them under controlled conditions. Data for juvenile and adult M. edulis bivalves cultured in this study, and previously by Wanamaker et al. (2006), yielded statistically identical paleotemperature relationships. On the basis of these experiments we have developed a species-specific paleotemperature equation for the bivalve M. …

Balanced Proper Orthogonal Decomposition For Model Reduction Of Infinite Dimensional Linear Systems, John R. Singler, Belinda A. Batten

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we extend a method for reduced order model derivation for finite dimensional systems developed by Rowley to infinite dimensional systems. The method is related to standard balanced truncation, but includes aspects of the proper orthogonal decomposition in its computational approach. The method is also applicable to nonlinear systems. The method is applied to a convection diffusion equation.

Random Effects Models In A Meta-Analysis Of The Accuracy Of Diagnostic Tests Within A Gold Standard In The Presence Of Missing Data, Haitao Chu, Sining Chen, Thomas A. Louis

Johns Hopkins University, Dept. of Biostatistics Working Papers

In evaluating the accuracy of diagnosis tests, it is common to apply two imperfect tests jointly or sequentially to a study population. In a recent meta-analysis of the accuracy of microsatellite instability testing (MSI) and traditional mutation analysis (MUT) in predicting germline mutations of the mismatch repair (MMR) genes, a Bayesian approach (Chen, Watson, and Parmigiani 2005) was proposed to handle missing data resulting from partial testing and the lack of a gold standard. In this paper, we demonstrate an improved estimation of the sensitivities and specificities of MSI and MUT by using a nonlinear mixed model and a Bayesian …

Constant-Sign Solutions Of A System Of Integral Equations With Integrable Singularities, Ravi P. Agarwal, Donal O'Regan, Patricia J.Y. Wong

Mathematics and System Engineering Faculty Publications

We consider the following systems of Fredholm integral equations and the system of Volterra integral equations where the nonlinearities fi, 1 ≤ i ≤ n may be singular in the independent variable and may also be singular at uj = 0, j ∈ {1, 2,..., n}. Our aim is to establish criteria such that the above systems have at least one constant-sign solution (u1, u2,..., un), i.e., for each 1 ≤ i ≤ n, Θiui ≥ 0 where Θi ∈ {1,-1} is fixed. © 2007 Rocky Mountain Mathematics Consortium.

The Metallo-Β-Lactamase Gob Is A Mono-Zn(Ii) Enzyme With A Novel Active Site, Jorgelina Morrán-Barrio, Javier M. Gonzalez, Mariá Natalia Lisa, Alison L. Costello, Matteo Dal Peraro, Paolo Carloni, Brian Bennett, David L. Tierney, Adriana S. Limansky, Alejandro M. Viale, Alejandro J. Vila

Physics Faculty Research and Publications

Metallo-β-lactamases (MβLs) are zinc-dependent enzymes able to hydrolyze and inactivate most β-lactam antibiotics. The large diversity of active site structures and metal content among MβLs from different sources has limited the design of a pan-MβL inhibitor. Here we report the biochemical and biophysical characterization of a novel MβL, GOB-18, from a clinical isolate of a Gram-negative opportunistic pathogen, Elizabethkingia meningoseptica. Different spectroscopic techniques, three-dimensional modeling, and mutagenesis experiments, reveal that the Zn(II) ion is bound to Asp¹²⁰, His¹²¹, His²⁶³, and a solvent molecule, i.e. in the canonical Zn2 site of dinuclear MβLs. Contrasting …

Asp-120 Locates Zn2 For Optimal Metallo-Β-Lactamase Activity, Leticia L. Llarrull, Stella M. Fabiane, Jason M. Kowalski, Brian Bennett, Brian J. Sutton, Alejandro J. Vila

Physics Faculty Research and Publications

Metallo-β-lactamases are zinc-dependent hydrolases that inactivate β-lactam antibiotics, rendering bacteria resistant to them. Asp-120 is fully conserved in all metallo-β-lactamases and is central to catalysis. Several roles have been proposed for Asp-120, but so far there is no agreed consensus. We generated four site-specifically substituted variants of the enzyme BcII from Bacillus cereus as follows: D120N, D120E, D120Q, and D120S. Replacement of Asp-120 by other residues with very different metal ligating capabilities severely impairs the lactamase activity without abolishing metal binding to the mutated site. A kinetic study of these mutants indicates that Asp-120 is not the proton donor, nor …

Thermal Entanglement Of Two Interacting Qubits In A Static Magnetic Field, G. Lagmago Kamta, Andrei Y. Istomin, Anthony F. Starace

Anthony F. Starace Publications

We study systematically the entanglement of a two-qubit Heisenberg XY model in thermal equilibrium in the presence of an external arbitrarily-directed static magnetic field, thereby generalizing our prior work [G. Lagmago Kamta, A.F. Starace, Phys. Rev. Lett. 88, 107901 (2002)]. We show that a magnetic field having a component in the xy-plane containing the spin-spin interaction components produces different entanglement for ferromagnetic (FM) and antiferromagnetic (AFM) couplings. In particular, quantum phase transitions induced by the magnetic field-driven level crossings always occur for the AFM-coupled qubits, but only occur in FM-coupled qubits when the coupling is of Ising type or …

Perfluoroalkyl Sulfonates And Perfluorocarboxylates In Two Wastewater Treatment Facilities In Kentucky And Georgia, Bommanna Loganathan 8093044, Kenneth S. Sajwan, Evan Sinclair, Kurunthachalam Senthil Kumar, Kurunthachalam Kannan

Bommanna Loganathan

Modification Of Carboplatin By Jurkat Cells, Anthony J. Di Pasqua, Jerry Goodisman, Deborah J. Kerwood, Bonnie B. Toms, James C. Dabrowiak

Chemistry - All Scholarship

Using [¹H,¹⁵N] heteronuclear single quantum coherance (HSQC) NMR and ¹⁵N-labeled carboplatin, 1, we show that Jurkat cells affect the rate of disappearance of the HSQC NMR peak in culture medium for this Pt²⁺ anticancer drug. The decay or disappearance rate constant for 1 in culture medium containing cells is k₁ = k_c [CO₃^{2 -}] + k_m + k_u N, where k_c is the rate constant for reaction of 1 with carbonate in the medium, k_m is the rate constant for reaction of 1 with all …

Coexistence Of Superfluid And Mott Phases Of Lattice Bosons, R. A. Barankov, Courtney Lannert, S. Vishveshwara

Physics: Faculty Publications

Recent experiments on strongly interacting bosons in optical lattices have revealed the coexistence of spatially separated Mott-insulating and number-fluctuating phases. We explore the condensate properties of the number fluctuating phase trapped between the Mott-insulating regions and derive the associated collective-mode structure. We discuss the crossover of the interlayer properties between two- and three-dimensional behavior as a function of the lattice parameters and estimate the critical temperatures for the transition from the normal to superfluid state.

Determination Of Interphase Line Tension In Langmuir Films, Jacob R. Wintersmith '06, Lu Zou, Andrew J. Bernoff, James C. Alexander, J. Adin Mann Jr.

All HMC Faculty Publications and Research

A Langmuir film is a molecularly thin film on the surface of a fluid; we study the evolution of a Langmuir film with two coexisting fluid phases driven by an interphase line tension and damped by the viscous drag of the underlying subfluid. Experimentally, we study a 4^′-8-alkyl[1,1^′-biphenyl]-4-carbonitrile (8CB) Langmuir film via digitally imaged Brewster angle microscopy in a four-roll mill setup which applies a transient strain and images the response. When a compact domain is stretched by the imposed strain, it first assumes a bola shape with two tear-drop shaped reservoirs connected by a thin …

Relationship Web: Realizing The Memex Vision With The Help Of Semantic Web, Amit P. Sheth

Kno.e.sis Publications

Relationship Web takes us from "which document" could have information I need to "what's in the resources" that gives me the insight and knowledge I need for decision making. Dr. Vannevar Bush outlined his vision for Memex in a 1945 Atlantic Monthly article [1]. Describing how the human brain navigates an information space in what he called trailblazing, Dr. Bush said, "It operates by association. With one item in its grasp, it snaps instantly to the next that is suggested by the association of thoughts, in accordance with some intricate web of trails carried by the cells of the brain." …

Stout, Alice Virginia, 1908-1983 (Sc 1495), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid and scans (Click on "Additional Files" below) for Manuscripts Small Collection 1495. Journal kept by Stout describing the 1937 Ohio River flood in Louisville, Kentucky. Also includes some telegrams sent to her family in Bowling Green, Kentucky during the same period; photographs of the flood; and clippings about the family and the Cortlandt Hotel, where Stout resided during the flood.

Along-Strike Trace Element And Isotopic Variation In Aleutian Island Arc Basalt: Subduction Melts Sediments And Dehydrates Serpentine, Brad S. Singer, Brian R. Jicha, William P. Leeman, Nick W. Rogers, Matthew F. Thirlwall, Jeffrey G. Ryan, Kirsten E. Nicolaysen

Geology Faculty Publications

Trace element and Sr-Nd-Pb isotope compositions of basaltic lavas from 11 volcanoes spanning 1300 km of the Aleutian Island arc provide new constraints on the recycling of elements in melts and fluids derived from subducted oceanic crust and sediment. Despite a nearly twofold variation in the flux of sediment subducted along the Aleutians, proxies indicating the presence of sediment melt in the magma source, including Th/La and Th/Nd, do not vary systematically along strike. In contrast, ratios including B/La, B/Nb, B/Be, Cs/La, Pb/Ce, and Li/Y suggest that the quantity or composition of fluid transferred from the slab into the mantle …

Soil Moisture Variations And Ecosystem-Scale Fluxes Of Water And Carbon In Semiarid Grassland And Shrubland, S. A. Kurc, Eric E. Small

Environmental Science and Geology Faculty Research Publications

Soil moisture distribution emerges as a key link between hydrologic and ecologic processes in semiarid grassland and shrubland, as it influences evapotranspiration, respiration, and assimilation. In support, we present three years of data (2002–2004) collected from a semiarid grassland and shrubland within the Sevilleta National Wildlife Refuge of central New Mexico; the two sites are separated by about 5 km. Instrumentation includes an eddy covariance tower and typical micrometeorological devices at both locations. Additionally, the grassland site features six soil moisture profiles and the shrubland site features four soil moisture profiles, with the maximum depth at 52.5 cm. At both …

Taunton River Watershed - Town Map

Maps

No abstract provided.

Evaluating Discontinuities In Complex Systems: Toward Quantitative Measures Of Resilience, Craig Stow, Craig R. Allen, Ahjond S. Garmestani

United States Geological Survey: Staff Publications

The textural discontinuity hypothesis (TDH) is based on the observation that animal body mass distributions exhibit discontinuities that may reflect the texture of the landscape available for exploitation. This idea has been extended to other complex systems, hinting that the identification and quantification of discontinuities in the distributions of appropriate variables may provide clues to emergent system properties such as resilience. We propose a discontinuity index, based on the vector norm of the full assemblage of observed discontinuities, as a means to quantify and compare this characteristic among systems. We also evaluate four methods to identify the number and location …

Optically Thick [O I] And [C Ii] Emission Toward Ngc 6334a, N. P. Abel, A. P. Sarma, Thomas H. Troland, Gary J. Ferland

Physics and Astronomy Faculty Publications

This work focuses on [O I] and [C II] emission toward NGC 6334A, an embedded H⁺ region/PDR only observable at infrared or longer wavelengths. A geometry in which nearly all the emission escapes out the side of the cloud facing the stars, such as Orion, is not applicable to this region. Instead, we find the geometry to be one in which the H⁺ region and associated PDR is embedded in the molecular cloud. Constant-density PDR calculations are presented which predict line intensities as a function of A_V [or N(H)], hydrogen density (n_H), and …

Use Of Personal Digital Assistants (Pdas) In Medical Education, Rattiporn Luanrattana, Khin Than Win, John Fulcher

Faculty of Informatics - Papers (Archive)

A systematic review of how the personal digital assistants (PDAs) have been used in healthcare professions and medical education has been conducted in order to identify current usage of PDAs in both areas. The major aim of this research is to study the feasibility of incorporating PDAs into problem-based learning (PBL) medical education. A systematic review was conducted by exploring various databases on the use of PDAs in two major areas: the healthcare professions and medical education during the period 2000-2006. Results: The needs, patterns and functionalities of using PDAs in the medical profession have been identified and categorized into …

Strain And Rotation Rate From Gps In Tibet, Anatolia, And The Altiplano, Richard W. Allmendinger, Robert Reilinger, John P. Loveless

Geosciences: Faculty Publications

Deformation measured by regional GPS networks in continental plateaus reflects the geologic and tectonic variability of the plateaus. For two collisional plateaus (Tibet and Anatolia) and one noncollisional (the Altiplano), we analyze the regional strain and rotation rate by inverting GPS velocities to calculate the full two-dimensional velocity gradient tensor. To test the method, we use gridded velocities determined from an elastic block model for the eastern Mediterranean/Middle East region and show that to a first order, the deformation calculated directly from the GPS vectors provides an accurate description of regional deformation patterns. Principal shortening and extension rate axes, vertical …