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Superfluid Transition In A Rotating Fermi Gas With Resonant Interactions, Martin Y. Veillette, Daniel E. Sheehy, Leo Radzihovsky, Victor Gurarie Dec 2006

Superfluid Transition In A Rotating Fermi Gas With Resonant Interactions, Martin Y. Veillette, Daniel E. Sheehy, Leo Radzihovsky, Victor Gurarie

Faculty Publications

We study a rotating atomic Fermi gas near a narrow s-wave Feshbach resonance in a uniaxial trap with frequencies Ω⊥, Ωz. We predict the upper-critical angular velocity, ωc2(δ,T), as a function of temperature T and detuning δ across the BEC-BCS crossover. The suppression of superfluidity at ωc2 is distinct in the BCS and BEC regimes, with the former controlled by depairing and the latter by the dilution of bosonic molecules. At low T and Ωz 〉 Ω⊥, in the BCS and crossover regimes of 0 δ δc, ωc2 is implicitly given by ωc22+Ω2 ≈ 2Δ Ω/F, vanishing as ωc2∼Ω (1-δ/δc)1/2 …


Epinecrophylla, A New Genus Of Antwrens (Aves: Passeriformes: Thamnophilidae), Morton L. Isler, Daniela Rodrigues Lacerda, Phyllis R. Isler, Shannon J. Hackett, Kenneth V. Rosenberg, Robb T. Brumfield Dec 2006

Epinecrophylla, A New Genus Of Antwrens (Aves: Passeriformes: Thamnophilidae), Morton L. Isler, Daniela Rodrigues Lacerda, Phyllis R. Isler, Shannon J. Hackett, Kenneth V. Rosenberg, Robb T. Brumfield

Faculty Publications

We offer a new generic name for the stipple-throated assemblage of antwrens (Thamnophilidae) currently placed in the genus Myrmotherula. Molecular studies demonstrated that Myrmotherula is polyphyletic, with the stippled-throated group forming a clade that is not sister to any other currently recognized Myrmotherula species. The stipple-throated assemblage is distinguished morphologically by at least one sex having a black throat stippled white or buffy white combined with a comparatively long, unmarked tail, although three populations considered subspecies have lost one of these characters. The distinct evolution of this assemblage is supported by diagnostic behavioral characters derived from foraging behaviors, vocal repertoires, …


Uniform Discretizations: A New Approach For The Quantization Of Totally Constrained Systems, Miguel Campiglia, Cayetano Di Bartolo, Rodolfo Gambini, Jorge Pullin Dec 2006

Uniform Discretizations: A New Approach For The Quantization Of Totally Constrained Systems, Miguel Campiglia, Cayetano Di Bartolo, Rodolfo Gambini, Jorge Pullin

Faculty Publications

We discuss in detail the uniform discretization approach to the quantization of totally constrained theories. This approach allows to construct the continuum theory of interest as a well defined, controlled, limit of well behaved discrete theories. We work out several finite dimensional examples that exhibit behaviors expected to be of importance in the quantization of gravity. We also work out the case of BF theory. At the time of quantization, one can take two points of view. The technique can be used to define, upon taking the continuum limit, the space of physical states of the continuum constrained theory of …


A Search For Neutrinos From The Solar Hep Reaction And The Diffuse Supernova Neutrino Background With The Sudbury Neutrino Observatory, B. Aharmim, S. N. Ahmed, A. E. Anthony, E. W. Beier, A. Bellerive, M. Bergevin, S. D. Biller, M. G. Boulay, Y. D. Chan, M. Chen, X. Chen, B. T. Cleveland, G. A. Cox, C. A. Currat, X. Dai, F. Dalnoki-Veress, H. Deng, J. Detwiler, M. Dimarco, P. J. Doe, G. Doucas, P. L. Drouin, F. A. Duncan, M. Dunford, J. A. Dunmore, E. D. Earle, H. C. Evans, G. T. Ewan Dec 2006

A Search For Neutrinos From The Solar Hep Reaction And The Diffuse Supernova Neutrino Background With The Sudbury Neutrino Observatory, B. Aharmim, S. N. Ahmed, A. E. Anthony, E. W. Beier, A. Bellerive, M. Bergevin, S. D. Biller, M. G. Boulay, Y. D. Chan, M. Chen, X. Chen, B. T. Cleveland, G. A. Cox, C. A. Currat, X. Dai, F. Dalnoki-Veress, H. Deng, J. Detwiler, M. Dimarco, P. J. Doe, G. Doucas, P. L. Drouin, F. A. Duncan, M. Dunford, J. A. Dunmore, E. D. Earle, H. C. Evans, G. T. Ewan

Faculty Publications

A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB) using data collected during the first operational phase of the Sudbury Neutrino Observatory, with an exposure of 0.65 ktons yr. For the hep neutrino search, two events are observed in the effective electron energy range of 14.3 MeV < Teff < 20 MeV, where 3.1 background events are expected. After accounting for neutrino oscillations, an upper limit of 2.3 × 104 cm-2 s-1 at the 90% confidence level is inferred on the integral total flux of hep neutrinos. For DSNB neutrinos, no events are observed in the effective electron energy range of 21 MeV < Teff < 35 MeV, and, consequently, an upper limit on the νe component of the DSNB flux in the neutrino energy range of 22.9 MeV < Eν < 36.9 MeVof 70 cm-2 s-1 is inferred at the 90% confidence level. This is an improvement by a factor of 6.5 on the previous best upper limit on the hep neutrino flux and by 2 orders of magnitude on the previous upper limit on the νe component of the DSNB flux. © 2006. The American Astronomical Society. All rights reserved.


Geological And Oceanographic Perspectives On Event Bed Formation During Hurricane Katrina, T. R. Keen, Y. Furukawa, S. J. Bentley, R. L. Slingerland, W. J. Teague, J. D. Dykes, C. D. Rowley Dec 2006

Geological And Oceanographic Perspectives On Event Bed Formation During Hurricane Katrina, T. R. Keen, Y. Furukawa, S. J. Bentley, R. L. Slingerland, W. J. Teague, J. D. Dykes, C. D. Rowley

Faculty Publications

Storm deposits in ancient shelf sediments typically form thick sequences of interbedded sand and mud deposited during shoreline regression, whereas modern shelf sediments are generally thin veneers deposited during shoreline transgression. In this paper we present a preliminary comparison between ancient and modern storm beds deposited in these disparate contexts. Hurricane Katrina deposited a storm bed on the Louisiana shelf with a maximum observed thickness of 0.58 m, which thinned to approximately 0.1 m at 200 km west of landfall. This thickness is similar to event beds observed in both ancient and modern sediments. Using data for tropical cyclone landfalls …


Horospherical Model For Holomorphic Discrete Series And Horospherical Cauchy Transform, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson Dec 2006

Horospherical Model For Holomorphic Discrete Series And Horospherical Cauchy Transform, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson

Faculty Publications

We define a complex horospherical transform on an affine symmetric space X = G/H of Hermitian type and show that it has no kernel on the representations of the H-spherical holomorphic discrete series. © Foundation Compositio Mathematica 2006.


On The Head And The Tail Of The Colored Jones Polynomial, Oliver T. Dasbach, Xiao Song Lin Dec 2006

On The Head And The Tail Of The Colored Jones Polynomial, Oliver T. Dasbach, Xiao Song Lin

Faculty Publications

The colored Jones polynomial is a function JK: ℕ → ℤ[t,t-1] associated with a knot K in 3-space. We will show that for an alternating knot K the absolute values of the first and the last three leading coefficients of JK(n) are independent of n when n is sufficiently large. Computation of sample knots indicates that this should be true for any fixed leading coefficient of the colored Jones polynomial for alternating knots. As a corollary we get a volume-ish theorem for the colored Jones polynomial. © Foundation Compositio Mathematica 2006.


Rapid Decay Of Tree-Community Composition In Amazonian Forest Fragments, William F. Laurance, Henrique E.M. Nascimento, Susan G. Laurance, Ana Andrade, José E.L.S. Ribeiro, Juan Pablo Giraldo, Thomas E. Lovejoy, Richard Condit, Jerome Chave, Kyle E. Harms, Sammya D'Angelo Dec 2006

Rapid Decay Of Tree-Community Composition In Amazonian Forest Fragments, William F. Laurance, Henrique E.M. Nascimento, Susan G. Laurance, Ana Andrade, José E.L.S. Ribeiro, Juan Pablo Giraldo, Thomas E. Lovejoy, Richard Condit, Jerome Chave, Kyle E. Harms, Sammya D'Angelo

Faculty Publications

Forest fragmentation is considered a greater threat to vertebrates than to tree communities because individual trees are typically long-lived and require only small areas for survival. Here we show that forest fragmentation provokes surprisingly rapid and profound alterations in Amazonian tree-community composition. Results were derived from a 22-year study of exceptionally diverse tree communities in 40 1-ha plots in fragmented and intact forests, which were sampled repeatedly before and after fragment isolation. Within these plots, trajectories of change in abundance were assessed for 267 genera and 1,162 tree species. Abrupt shifts in floristic composition were driven by sharply accelerated tree …


Detection Of The Irradiated Donor In The Lmxbs 4u 1636-536 (=V801 Ara) And 4u 1735-444 (=V926 Sco), J. Casares, R. Cornelisse, D. Steeghs, P. A. Charles, R. I. Hynes, K. O'Brien, T. E. Strohmayer Dec 2006

Detection Of The Irradiated Donor In The Lmxbs 4u 1636-536 (=V801 Ara) And 4u 1735-444 (=V926 Sco), J. Casares, R. Cornelisse, D. Steeghs, P. A. Charles, R. I. Hynes, K. O'Brien, T. E. Strohmayer

Faculty Publications

Phase-resolved VLT spectroscopy of the bursting low-mass X-ray binaries 4U 1636-536/V801 Ara and 4U 1735-444/V926 Sco is presented. Doppler images of the N III λ4640 Bowen transition reveal compact spots which we attribute to fluorescent emission from the donor star and enable us to define a new set of spectroscopic ephemerides. We measure K em = 277 ± 22 and 226 ± 22 kms -1 from the N III spots in V801 Ara and V926 Sco, respectively, which represent strict lower limits to the radial velocity semi-amplitude of the donor stars. Our new ephemerides provide confirmation that light-curve maxima in …


Holomorphic Horospherical Transform On Noncompactly Causal Spaces, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson Dec 2006

Holomorphic Horospherical Transform On Noncompactly Causal Spaces, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson

Faculty Publications

We develop integral geometry for noncompactly causal symmetric spaces. We define a complex horospherical transform and, for some cases, identify it with a Cauchy-type integral.


Early Spectral Evolution Of Nova Sagittarii 2004 (V5114 Sagittarii), A. Ederoclite, E. Mason, M. Della Valle, R. Gilmozzi, R. E. Williams, L. Germany, I. Saviane, F. Matteucci, B. E. Schaefer, F. Walter, R. J. Rudy, D. Lynch, S. Mazuk, C. C. Venturini, R. C. Puetter, R. B. Perry, W. Liller, A. Rotter Dec 2006

Early Spectral Evolution Of Nova Sagittarii 2004 (V5114 Sagittarii), A. Ederoclite, E. Mason, M. Della Valle, R. Gilmozzi, R. E. Williams, L. Germany, I. Saviane, F. Matteucci, B. E. Schaefer, F. Walter, R. J. Rudy, D. Lynch, S. Mazuk, C. C. Venturini, R. C. Puetter, R. B. Perry, W. Liller, A. Rotter

Faculty Publications

Aims. We present optical and near-infrared spectral evolution of the Galactic nova V5114 Sgr (2004) during few months after the outburst. Methods. We use multi-band photometry and line intensities derived from spectroscopy to put constrains on the distance and the physical conditions of the ejecta of V5114 Sgr. Results. The nova showed a fast decline to - 11 days) and spectral features of Fen spectroscopic class. It reached Mv = -8.7 ± 0.2 mag at maximum light, from which we derive a distance of 7700 ± 700 kpc and a distance from the galactic plane of about 800 pc. Hydrogen …


M-Body Pure State Entanglement, Feng Pan, J. P. Draayer Dec 2006

M-Body Pure State Entanglement, Feng Pan, J. P. Draayer

Faculty Publications

The simple entanglement of N-body N-particle pure states is extended to the more general M-body or M-body N-particle states where N ≠ M. Some new features of the M-body N-particle pure states a re discussed. An application of the measure to quantify quantum correlations in a Bose-Einstien condensate model is demonstrated. © 2006 World Scientific Publishing Company.


Fundamental Spatio-Temporal Decoherence: A Key To Solving The Conceptual Problems Of Black Holes, Cosmology And Quantum Mechanics, Rodolfo Gambini, Rafael A. Porto, Jorge Pullin Dec 2006

Fundamental Spatio-Temporal Decoherence: A Key To Solving The Conceptual Problems Of Black Holes, Cosmology And Quantum Mechanics, Rodolfo Gambini, Rafael A. Porto, Jorge Pullin

Faculty Publications

Unitarity is a pillar of quantum theory. Nevertheless, it is also a source of several of its conceptual problems. We note that in a world where measurements are relational, as is the case in gravitation, quantum mechanics exhibits a fundamental level of loss of coherence. This can be the key to solving, among others, the puzzles posed by the black hole information paradox, the formation of inhomogeneities in cosmology and the measurement problem in quantum mechanics. © World Scientific Publishing Company.


Sines Of A Nearly Perfect Character, David A. Ray, Jinchuan Xing, Abdel Halim Salem, Mark A. Batzer Dec 2006

Sines Of A Nearly Perfect Character, David A. Ray, Jinchuan Xing, Abdel Halim Salem, Mark A. Batzer

Faculty Publications

Mobile elements have been recognized as powerful tools for phylogenetic and population-level analyses. However, issues regarding potential sources of homoplasy and other misleading events have been raised. We have collected available data for all phylogenetic and population level studies of primates utilizing Alu insertion data and examined them for potentially homoplasious and other misleading events. Very low levels of each potential confounding factor in a phylogenetic or population analysis (i.e., lineage sorting, parallel insertions, and precise excision) were found. Although taxa known to be subject to high levels of these types of events may indeed be subject to problems when …


Homogenization And Field Concentrations In Heterogeneous Media, Robert Lipton Dec 2006

Homogenization And Field Concentrations In Heterogeneous Media, Robert Lipton

Faculty Publications

A multiscale characterization of the field concentrations inside composite and polycrystalline media is developed. We focus on gradient fields associated with the intensive quantities given by the temperature and the electric potential. In the linear regime these quantities are modeled by the solution of a second order elliptic partial differential equation with oscillatory coefficients. The characteristic length scale of the heterogeneity relative to the sample size is denoted by ε and the intensive quantity is denoted by u ε. Field concentrations are measured using the L p norm of the gradient field ||∇u ε||L p(D) for 2 ≤ p < ∞. The analysis focuses on the case when 0 < ε ≪ 1. Explicit lower bounds on lim inf ε→0 are developed. These bounds provide a way to rigorously assess field concentrations generated by the microgeometry without having to compute the actual field u ε. © 2006 Society for Industrial and Applied Mathematics.


Optimization Of Composite Structures Subject To Local Stress Constraints, Robert Lipton, Michael Stuebner Dec 2006

Optimization Of Composite Structures Subject To Local Stress Constraints, Robert Lipton, Michael Stuebner

Faculty Publications

An extension of current methodologies is introduced for optimization of graded microstructure subject to local stress criteria. The method is based on new multiscale stress criteria given by macrostress modulation functions. The modulation functions quantify the intensity of local stress fluctuations at the scale of the microstructure due to the imposed macroscopic stress. The methodology is illustrated for long cylindrical shafts reinforced with stiff cylindrical elastic fibers with generators parallel to the shaft. Examples are presented for shaft cross sections that possess reentrant corners typically seen in lap joints and junctions of struts. It is shown that the computational methodology …


The Central Laser Facility At The Pierre Auger Observatory, B. Fick, M. Malek, J. A.J. Matthews, J. Matthews, R. Meyhandan, M. Mostafá, M. Roberts, P. Sommers, L. Wiencke Nov 2006

The Central Laser Facility At The Pierre Auger Observatory, B. Fick, M. Malek, J. A.J. Matthews, J. Matthews, R. Meyhandan, M. Mostafá, M. Roberts, P. Sommers, L. Wiencke

Faculty Publications

The Central Laser Facility is located near the middle of the Pierre Auger Observatory in Argentina. It features an ultraviolet laser and optical components that direct a beam of calibrated, pulsed light into the sky. Light scattered from this beam produces tracks in the Auger optical detectors, which normally record nitrogen fluorescence tracks from cosmic ray air showers. The Central Laser Facility acts as a "test beam" that is used to investigate properties of the atmosphere and the air fluorescence detectors. Additionally, the laser can send a light pulse via optical fiber to the nearest surface detector tank. This signal, …


Emergence Of Primate Genes By Retrotransposon-Mediated Sequence Transduction, Jinchuan Xing, Hui Wang, Victoria P. Belancio, Richard Cordaux, Prescott L. Deininger, Mark A. Batzer Nov 2006

Emergence Of Primate Genes By Retrotransposon-Mediated Sequence Transduction, Jinchuan Xing, Hui Wang, Victoria P. Belancio, Richard Cordaux, Prescott L. Deininger, Mark A. Batzer

Faculty Publications

Gene duplication is one of the most important mechanisms for creating new genes and generating genomic novelty. Retrotransposon-mediated sequence transduction (i.e., the process by which a retrotransposon carries flanking sequence during its mobilization) has been proposed as a gene duplication mechanism. L1 exon shuffling potential has been reported in cell culture assays, and two potential L1-mediated exon shuffling events have been identified in the genome. SVA is the youngest retrotransposon family in primates and is capable of 3′ flanking sequence transduction during retrotransposition. In this study, we examined all of the full-length SVA elements in the human genome to assess …


Spatial Separation Of Large Dynamical Blueshift And Harmonic Generation, Mette B. Gaarde, Mitsuko Murakami, Reinhard Kienberger Nov 2006

Spatial Separation Of Large Dynamical Blueshift And Harmonic Generation, Mette B. Gaarde, Mitsuko Murakami, Reinhard Kienberger

Faculty Publications

We study the temporal and spatial dynamics of the large amplitude and frequency modulation that can be induced in an intense, few cycle laser pulse as it propagates through a rapidly ionizing gas. Our calculations include both single atom and macroscopic interactions between the nonlinear medium and the laser field. We analyze the harmonic generation by such pulses and show that it is spatially separated from the ionization dynamics which produce a large dynamical blueshift of the laser pulse. This means that small changes in the initial laser focusing conditions can lead to large differences in the laser frequency modulation, …


Electrophile-Induced Ether Transfer: A New Approach To Polyketide Structural Units, Kai Liu, Richard E. Taylor, Rendy Kartika Nov 2006

Electrophile-Induced Ether Transfer: A New Approach To Polyketide Structural Units, Kai Liu, Richard E. Taylor, Rendy Kartika

Faculty Publications

A strategically novel approach to the formation of syn-1,3-diol mono- and diethers through electrophilic activation of homoallylic alkoxymethyl ethers has been developed. The resulting polyketide-like synthetic fragments are generated in good yield and with excellent stereocontrol. A chairlike transition state is proposed to account for the high stereoselectivity. Varying the conditions of the reaction workup results in the efficient generation of mono- and diether containing structural units common to polyketide natural products. © 2006 American Chemical Society.


Nodal Structure Of Unconventional Superconductors Probed By Angle Resolved Thermal Transport Measurements, Y. Matsuda, K. Izawa, I. Vekhter Nov 2006

Nodal Structure Of Unconventional Superconductors Probed By Angle Resolved Thermal Transport Measurements, Y. Matsuda, K. Izawa, I. Vekhter

Faculty Publications

Over the past two decades, unconventional superconductivity with gap symmetry other than s wave has been found in several classes of materials, including heavy fermion, high Tc, and organic superconductors. Unconventional superconductivity is characterized by anisotropic superconducting gap functions, which may have zeros (nodes) along certain directions in the Brillouin zone. The nodal structure is closely related to the pairing interaction, and it is widely believed that the presence of nodes is a signature of magnetic or some other exotic, rather than conventional phonon mediated, pairing mechanism. Therefore experimental determination of the gap function is of fundamental importance. However, the …


Density Of States, Entropy, And The Superconducting Pomeranchuk Effect In Pauli-Limited Al Films, X. S. Wu, P. W. Adams, G. Catelani Nov 2006

Density Of States, Entropy, And The Superconducting Pomeranchuk Effect In Pauli-Limited Al Films, X. S. Wu, P. W. Adams, G. Catelani

Faculty Publications

We present low-temperature tunneling density of states measurements of Pauli-limited Al films in which the Zeeman and orbital contributions to the critical field are comparable. We show that films in the thickness range of 6-7 nm exhibit a reentrant parallel critical field transition which is associated with a high-entropy superconducting phase, similar to the high-entropy solid phase of He3 responsible for the Pomeranchuk effect. This phase is characterized by an excess of states near the Fermi energy so long as the parallel critical field transition remains second order. Theoretical fits to the zero-bias tunneling conductance are in good agreement with …


Further Evidence For Variable Synchrotron Emission In Xte J1118+480 In Outburst, R. I. Hynes, E. L. Robinson, K. J. Pearson, D. M. Gelino, W. Cui, Y. Q. Xue, M. A. Wood, T. K. Watson, D. E. Winget, I. M. Silver Nov 2006

Further Evidence For Variable Synchrotron Emission In Xte J1118+480 In Outburst, R. I. Hynes, E. L. Robinson, K. J. Pearson, D. M. Gelino, W. Cui, Y. Q. Xue, M. A. Wood, T. K. Watson, D. E. Winget, I. M. Silver

Faculty Publications

We present simultaneous multicolor infrared and optical photometry of the black hole X-ray transient XTE Jill 8+480 during its short 2005 January outburst, supported by simultaneous X-ray observations. The variability is dominated by short timescales, ∼10 s, although a weak superhump also appears to be present in the optical. The optical rapid variations, at least, are well correlated with those in X-rays. Infrared JHKS photometry, as in the previous outburst, exhibits especially large-amplitude variability. The spectral energy distribution (SED) of the variable infrared component can be fitted with a power law of slope α = -0.78 ± 0.07, where Fν …


Large Deviations For The Two-Dimensional Navier-Stokes Equations With Multiplicative Noise, S. S. Sritharan, P. Sundar Nov 2006

Large Deviations For The Two-Dimensional Navier-Stokes Equations With Multiplicative Noise, S. S. Sritharan, P. Sundar

Faculty Publications

A Wentzell-Freidlin type large deviation principle is established for the two-dimensional Navier-Stokes equations perturbed by a multiplicative noise in both bounded and unbounded domains. The large deviation principle is equivalent to the Laplace principle in our function space setting. Hence, the weak convergence approach is employed to obtain the Laplace principle for solutions of stochastic Navier-Stokes equations. The existence and uniqueness of a strong solution to (a) stochastic Navier-Stokes equations with a small multiplicative noise, and (b) Navier-Stokes equations with an additional Lipschitz continuous drift term are proved for unbounded domains which may be of independent interest. © 2006 Elsevier …


The Saccharomyces Cerevisiae Rna Polymerase Iii Recruitment Factor Subunits Brf1 And Bdp1 Impose A Strict Sequence Preference For The Downstream Half Of The Tata Box, Nick D. Tsihlis, Anne Grove Nov 2006

The Saccharomyces Cerevisiae Rna Polymerase Iii Recruitment Factor Subunits Brf1 And Bdp1 Impose A Strict Sequence Preference For The Downstream Half Of The Tata Box, Nick D. Tsihlis, Anne Grove

Faculty Publications

Association of the TATA-binding protein (TBP) with its cognate site within eukaryotic promoters is key to accurate and efficient transcriptional initiation. To achieve recruitment of Saccharomyces cerevisiae RNA polymerase III, TBP is associated with two additional factors, Brf1 and Bdp1, to form the initiation factor TFIIIB. Previous data have suggested that the structure or dynamics of the TBP-DNA complex may be altered upon entry of Brf1 and Bdp1 into the complex. We show here, using the altered specificity TBP mutant TBPm3 and an iterative in vitro selection assay, that entry of Brf1 and Bdp1 into the complex imposes a strict …


A Molecular Phylogenetic Analysis Of Strombid Gastropod Morphological Diversity, Jared M. Latiolais, Michael S. Taylor, Kaustuv Roy, Michael E. Hellberg Nov 2006

A Molecular Phylogenetic Analysis Of Strombid Gastropod Morphological Diversity, Jared M. Latiolais, Michael S. Taylor, Kaustuv Roy, Michael E. Hellberg

Faculty Publications

The shells of strombid gastropods show a wide variety of forms, ranging from small and fusiform to large and elaborately ornamented with a strongly flared outer lip. Here, we present the first species-level molecular phylogeny for strombids and use the resulting phylogenetic framework to explore relationships between species richness and morphological diversity. We use portions of one nuclear (325 bp of histone H3) and one mitochondrial (640 bp of cytochrome oxidase I, COI) gene to infer relationships within the two most species-rich genera in the Strombidae: Strombus and Lambis. We include 32 species of Strombus, representing 10 of 11 extant …


Geographic Variation In Clonal Structure In A Reef-Building Caribbean Coral, Acropora Palmata, Iliana B. Baums, Margaret W. Miller, Michael E. Hellberg Nov 2006

Geographic Variation In Clonal Structure In A Reef-Building Caribbean Coral, Acropora Palmata, Iliana B. Baums, Margaret W. Miller, Michael E. Hellberg

Faculty Publications

Species that build the physical structure of ecosystems often reproduce clonally, both in terrestrial (e.g., grasses, trees) and marine (e.g., corals, seagrasses) environments. The degree of clonality may vary over a species' range in accordance with the relative success of sexual and asexual recruitment. High genotypic (clonal) diversity of structural species may promote the species diversity and resilience of ecosystems in the face of environmental extremes. Conversely, low genotypic diversity may indicate an asexual strategy to maintain resources and genetic variation during population decline. Here, we use microsatellite markers to assess geographic variation in clonality in the coral Acropora palmata …


Siamese, A Plant-Specific Cell Cycle Regulator, Controls Endoreplication Onset In Arabidopsis Thaliana, Michelle L. Churchman, Matthew L. Brown, Naohiro Kato, Viktor Kirik, Martin Hülskamp, Dirk Inzé, Lieven De Veylder, Jason D. Walker, Ui Zheng, David G. Oppenheimer, Taylor Gwin, Jason Churchman, John C. Larkin Nov 2006

Siamese, A Plant-Specific Cell Cycle Regulator, Controls Endoreplication Onset In Arabidopsis Thaliana, Michelle L. Churchman, Matthew L. Brown, Naohiro Kato, Viktor Kirik, Martin Hülskamp, Dirk Inzé, Lieven De Veylder, Jason D. Walker, Ui Zheng, David G. Oppenheimer, Taylor Gwin, Jason Churchman, John C. Larkin

Faculty Publications

Recessive mutations in the SIAMESE (SIM) gene of Arabidopsis thaliana result in multicellular trichomes harboring individual nuclei with a low ploidy level, a phenotype strikingly different from that of wild-type trichomes, which are single cells with a nuclear DNA content of ∼16C to 32C. These observations suggested that SIM is required to suppress mitosis as part of the switch to endoreplication in trichomes. Here, we demonstrate that SIM encodes a nuclear-localized 14-kD protein containing a cyclin binding motif and a motif found in ICK/KRP (for interactors of Cdc2 kinase/Kip-related protein) cell cycle inhibitor proteins. Accordingly, SIM was found to associate …


An Organic White Light-Emitting Fluorophore, Youjun Yang, Mark Lowry, Corin M. Schowalter, Sayo O. Fakayode, Jorge O. Escobedo, Xiangyang Xu, Huating Zhang, Timothy J. Jensen, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin Nov 2006

An Organic White Light-Emitting Fluorophore, Youjun Yang, Mark Lowry, Corin M. Schowalter, Sayo O. Fakayode, Jorge O. Escobedo, Xiangyang Xu, Huating Zhang, Timothy J. Jensen, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin

Faculty Publications

The synthesis of new benzo[a]- and [b]xanthene dye frameworks is described. A unique benzo[a]xanthene, seminaphtho[a]fluorone (SNAFR-1), is studied in a variety of media. The optimization of solution parameters and excitation wavelengths allows SNAFR-1 to display red, green, and blue emission bands of approximately equal intensities and also to produce white light. Ratiometric red (anion) and green (neutral) emissions are observed upon varying solution pH. A pH-independent violet-blue emission band is due to the addition of nucleophiles to the benzylic carbon of SNAFR-1. © 2006 American Chemical Society.


Estradiol Interactions With Dopamine Antagonists In Mares: Prolactin Secretion And Reproductive Traits, K. K. Kelley, D. L. Thompson, W. A. Storer, P. B. Mitcham, R. M. Gilley, P. J. Burns Nov 2006

Estradiol Interactions With Dopamine Antagonists In Mares: Prolactin Secretion And Reproductive Traits, K. K. Kelley, D. L. Thompson, W. A. Storer, P. B. Mitcham, R. M. Gilley, P. J. Burns

Faculty Publications

Two experiments studied the effects of pretreatment with estradiol benzoate before treatment with a dopamine antagonist on prolactin secretion and reproductive traits in mares during (1) the seasonal anovulatory period and (2) the normal breeding season. Experiment 1 was performed in winter with 17 mares selected for low follicular activity. Nine mares received estradiol benzoate injections every other day for a total of 10 injections; 8 mares received similar injections of vehicle. Ten days after onset of injections, all mares were placed on daily injections of sulpiride (250 mg) for 35 days or until ovulation. Plasma prolactin concentrations were higher …