Digital Commons Network^™

Odoni’S Façade The House As Portrait In Renaissance Venice, Monika Schmitter

Monika Schmitter

No abstract provided.

Pld1 Is Overexpressed In An Er-Negative Mcf-7 Cell Line Variant And A Subset Of Phospho-Akt-Negative Breast Carcinomas, Kathleen Arcaro, J.M. Gozgit, B.T. Pentecost, S.A. Marconi, C.N. Otis

Kathleen Arcaro

We have used a novel variant of the human oestrogen receptor (ER)-positive MCF-7 cell line, TMX2-28, as a model to study breast cancer. TMX2-28 cells show no detectable levels of mRNA or protein expression for the ER and express basal cytokeratins (CKs) 5, 14, and 17. cDNA microarray comparison between TMX2-28 and its parent cell line, MCF-7, identified 1402 differentially expressed transcripts, one of which was, phospholipase D1 (PLD1). Using real-time RT-PCR, we confirmed that PLD1 mRNA levels are 10-fold higher in TMX2-28 cells than in MCF-7 cells. We next examined PLD1 expression in human breast carcinomas. Phospholipase D1 mRNA …

Sea Ice Feedback And Cenozoic Evolution Of Antarctic Climate And Ice Sheets, Robert M. Deconto, David Pollard, David Harwood

Robert M DeConto

The extent and thickness of Antarctic sea ice have important climatic effects on radiation balance, energy transfer between the atmosphere and ocean, and moisture availability. This paper explores the role of sea ice and related feedbacks in the Cenozoic evolution of Antarctic climate and ice sheets, using a numerical climate model with explicit, dynamical representations of sea ice and continental ice sheets. In a scenario of decreasing Cenozoic greenhouse gas concentrations, our model initiates continental glaciation before any significant sea ice forms around the continent. Once variable ice sheets are established, seasonal sea ice distribution is highly sensitive to orbital …

Biomimetic Interactions Of Proteins With Functionalized Nanoparticies: A Thermodynamic Study, M De, Cc You, S Srivastava, Vm Rotello

Vincent Rotello

Gold nanoparticles (NPs) functionalized with L-amino acid-terminated monolayers provide an effective platform for the recognition of protein surfaces. Isothermal titration calorimetry (ITC) was used to quantify the binding thermodynamics of these functional NPs with alpha-chymotrypsin (ChT), histone, and cytochrome c (CytC). The enthalpy and entropy changes for the complex formation depend upon the nanoparticle structure and the surface characteristics of the proteins, e.g., distributions of charged and hydrophobic residues on the surface. Enthalpy-entropy compensation studies on these NP-protein systems indicate an excellent linear correlation between DeltaH and TDeltaS with a slope (alpha) of 1.07 and an intercept (TDeltaS0) of 35.2 …

Genome-Scale Analysis Of Saccharomyces Cerevisiae Metabolism And Ethanol Production In Fed-Batch Culture, Radhakrishnan Mahadevan, Michael A. Henson

Michael A Henson

A dynamic flux balance model based on a genome-scale metabolic network reconstruction is developed for in silico analysis of Saccharomyces cerevisiae metabolism and ethanol production in fed-batch culture. Metabolic engineering strategies previously identified for their enhanced steady-state biomass and/or ethanol yields are evaluated for fed-batch performance in glucose and glucose/xylose media. Dynamic analysis is shown to provide a single quantitative measure of fed-batch ethanol productivity that explicitly handles the possible tradeoff between the biomass and ethanol yields. Productivity optimization conducted to rank achievable fed-batch performance demonstrates that the genetic manipulation strategy and the fed-batch operating policy should be considered simultaneously. …

Bankruptcy Risk And The Performance Of Tradable Permit Markets, John K. Stranlund, Wei Zhang

John K. Stranlund

We study the impact of bankruptcy risk on markets for tradable environmental and natural resource permits. We find that firms that risk bankruptcy demand more permits than if they were financially secure. Consequently, bankruptcy risk in a competitive market for tradable property rights causes an inefficient distribution of individual choices among regulated firms. Moreover, the equilibrium distribution of permits is not independent of the initial distribution of permits. In fact, the inefficiency that is associated with bankruptcy risk is mitigated if financially insecure firms are given a larger share of the initial allocation of permits.

A Liquid Xenon Ionization Chamber In An All-Fluoropolymer Vessel, F. Leport, Andrea Pocar, L. Bartoszek, R. Devoe, P. Fierlinger, B. Flatt, G. Gratta, M. Green, T. Koffas, M. Montero Diez, R. Neilson, K. O'Sullivan, S. Waldman, J. Wodin, D. Woisard, E. Baussan, M. Breidenbach, R. Conley, W. Fairbank Jr., J. Farine, C. Hall, K. Hall, D. Hallman, C. Hargrove, J. Hodgson, S. Jeng, D. S. Leonard, D. Mackay, Y. Martin, A. Odian, L. Ounalli, A. Piepke, C. Y. Prescott, P. C. Rowson, K. Skarpaas, D. Schenker, D. Sinclair, V. Stekhanov, V. Strickland, C. Virtue, J.-L. Vuilleumier, K. Wamba, P. Weber

Andrea Pocar

A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of an ultra-clean fluoropolymer. One such detector was operated inside a welded, He leak tight, all-fluoropolymer chamber. The measured energy resolution for 570 keV gamma rays is σ/E=5.1% at a drift field of 1.5 kV/cm, in line with the best values obtained for ionization only detectors run in LXe using conventional, metal vessels.

A Conserved Role For Kinesin-5 In Plant Mitosis, Alex Bannigan, Wolf-Rüdiger Scheible, Wolfgang Lukowitz, Carey Fagerstrom, Patricia Wadsworth, Chris Somerville, Tobias Baskin

Tobias Baskin

The mitotic spindle of vascular plants is assembled and maintained by processes that remain poorly explored at a molecular level. Here, we report that AtKRP125c, one of four kinesin-5 motor proteins in arabidopsis, decorates microtubules throughout the cell cycle and appears to function in both interphase and mitosis. In a temperature-sensitive mutant, interphase cortical microtubules are disorganized at the restrictive temperature and mitotic spindles are massively disrupted, consistent with a defect in the stabilization of anti-parallel microtubules in the spindle midzone, as previously described in kinesin-5 mutants from animals and yeast. AtKRP125c introduced into mammalian epithelial cells by transfection decorates …

Array-Based Sensing Of Proteins Using Conjugated Polymers, Or Miranda, Cc You, R Phillips, Ib Kim, Ps Ghosh, Uhf Bunz, Vm Rotello

Vincent Rotello

A sensor array comprising six functionalized poly(p-phenyleneethynylene) polymers was constructed and used to detect and identify protein analytes. The presence of proteins alters the fluorescence properties of the polymers, generating a distinct fluorescence response pattern for a given protein. Linear discriminant analyses accurately differentiate the patterns of 17 proteins at nano- to micromolar concentrations. An identification accuracy of 97% was obtained on the basis of the tests with 68 unknown protein samples from the training set.

Chronology Of The Drafting, Review, And Revision Of The Proposed Icomos Charter For The Interpretation And Presentation Of Cultural Heritage Sites, Neil A. Silberman

Neil A. Silberman

No abstract provided.

A Very Late Viral Protein Triggers The Lytic Release Of Sv40, Daniel Hebert, D . Sadowicz, R. Daniels

Daniel Hebert

How nonenveloped viruses such as simian virus 40 (SV40) trigger the lytic release of their progeny is poorly understood. Here, we demonstrate that SV40 expresses a novel later protein termed VP4 that triggers the timely lytic release of its progeny. Like VP3, VP4 synthesis initiates from a downstream AUG start codon within the VP2 transcript and localizes to the nucleus. However, VP4 expression occurs approximately 24 h later at a time that coincides with cell lysis, and it is not incorporated into mature virions. Mutation of the VP4 initiation codon from the SV40 genome delayed lysis by 2 d and …

Salinity Constraints On Subsurface Archaeal Diversity And Methanogenesis In Sedimentary Rock Rich In Organic Matter, Klaus R. Nusslein, P, J. Waldron, S. T. Petsch, A. M. Martini

Klaus R. Nusslein

The diversity of microorganisms active within sedimentary rocks provides important controls on the geochemistry of many subsurface environments. In particular, biodegradation of organic matter in sedimentary rocks contributes to the biogeochemical cycling of carbon and other elements and strongly impacts the recovery and quality of fossil fuel resources. In this study, archaeal diversity was investigated along a salinity gradient spanning 8 to 3,490 mM Cl− in a subsurface shale rich in CH4 derived from biodegradation of sedimentary hydrocarbons. Shale pore waters collected from wells in the main CH4-producing zone lacked electron acceptors such as O2, NO3−, Fe3+, or SO42−. Acetate …

Salinity Constraints On Subsurface Archaeal Diversity And Methanogenesis In Sedimentary Rock Rich In Organic Matter, Steven T. Petsch, P. Waldron, A. M. Martini, K. Nüsslein

Steven T. Petsch

The diversity of microorganisms active within sedimentary rocks provides important controls on the geochemistry of many subsurface environments. In particular, biodegradation of organic matter in sedimentary rocks contributes to the biogeochemical cycling of carbon and other elements and strongly impacts the recovery and quality of fossil fuel resources. In this study, archaeal diversity was investigated along a salinity gradient spanning 8 to 3,490 mM Cl− in a subsurface shale rich in CH4 derived from biodegradation of sedimentary hydrocarbons. Shale pore waters collected from wells in the main CH4-producing zone lacked electron acceptors such as O2, NO3−, Fe3+, or SO42−. Acetate …

Section 512 In The Educational Context, Laura Quilter

Laura Quilter

No abstract provided.

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 …

Genomics And Microarray Analysis Of Aromatics Degradation In Geobacter Metallireducens And Compan To A Geobacter Isolate From A Contaminated Fieldriso Site, Derek Lovley, Jessica E. Butler, Qiang He, Kelly P. Nevin, Zhili He, Jizhong Zhou

Derek Lovley

Background: Groundwater and subsurface environments contaminated with aromatic compounds can be remediated in situ by Geobacter species that couple oxidation of these compounds to reduction of Fe(III)-oxides. Geobacter metallireducens metabolizes many aromatic compounds, but the enzymes involved are not well known.

Results: The complete G. metallireducens genome contained a 300 kb island predicted to encode enzymes for the degradation of phenol, p-cresol, 4-hydroxybenzaldehyde, 4-hydroxybenzoate, benzyl alcohol, benzaldehyde, and benzoate. Toluene degradation genes were encoded in a separate region. None of these genes was found in closely related species that cannot degrade aromatic compounds. Abundant transposons and phage-like genes in the …

Lack Of Electricity Production By Pelobacter Carbinolicus Indicates That The Capacity For Fe(Iii) Oxide Reduction Does Not Necessarily Confer Electron Transfer Ability To Fuel Cell Anodes, Hanno Richter, Martin Lanthier, Kelly P. Nevin, Derek Lovley

Derek Lovley

The ability of Pelobacter carbinolicus to oxidize electron donors with electron transfer to the anodes of microbial fuel cells was evaluated because microorganisms closely related to Pelobacter species are generally abundant on the anodes of microbial fuel cells harvesting electricity from aquatic sediments. P. carbinolicus could not produce current in a microbial fuel cell with electron donors which support Fe(III) oxide reduction by this organism. Current was produced using a coculture of P. carbinolicus and Geobacter sulfurreducens with ethanol as the fuel. Ethanol consumption was associated with the transitory accumulation of acetate and hydrogen. G. sulfurreducens alone could not metabolize …

Lack Of Electricity Production By Pelobacter Carbinolicus Indicates That The Capacity For Fe(Iii) Oxide Reduction Does Not Necessarily Confer Electron Transfer Ability To Fuel Cell Anodes, Hanno Richter, Martin Lanthier, Kelly P. Nevin, Derek Lovley

Kelly Nevin

The ability of Pelobacter carbinolicus to oxidize electron donors with electron transfer to the anodes of microbial fuel cells was evaluated because microorganisms closely related to Pelobacter species are generally abundant on the anodes of microbial fuel cells harvesting electricity from aquatic sediments. P. carbinolicus could not produce current in a microbial fuel cell with electron donors which support Fe(III) oxide reduction by this organism. Current was produced using a coculture of P. carbinolicus and Geobacter sulfurreducens with ethanol as the fuel. Ethanol consumption was associated with the transitory accumulation of acetate and hydrogen. G. sulfurreducens alone could not metabolize …

Quantum Dots Coordinated With Conjugated Organic Ligands: New Nanomaterials With Novel Photophysics, Nathan L. Hammer, Todd Emrick, Michael Barnes

Michael Barnes

CdSe quantum dots functionalized with oligo-(phenylene vinylene) (OPV) ligands (CdSe-OPV nanostructures) represent a new class of composite nanomaterials with significantly modified photophysics relative to bulk blends or isolated components. Singlemolecule spectroscopy on these species have revealed novel photophysics such as enhanced energy transfer, spectral stability, and strongly modified excited state lifetimes and blinking statistics. Here, we review the role of ligands in quantum dot applications and summarize some of our recent efforts probing energy and charge transfer in hybrid CdSe-OPV composite nanostructures.

Quantum Dots Coordinated With Conjugated Organic Ligands: New Nanomaterials With Novel Photophysics, Nathan L. Hammer, Todd S. Emrick, Michael D. Barnes

Todd S. Emrick

CdSe quantum dots functionalized with oligo-(phenylene vinylene) (OPV) ligands (CdSe-OPV nanostructures) represent a new class of composite nanomaterials with significantly modified photophysics relative to bulk blends or isolated components. Singlemolecule spectroscopy on these species have revealed novel photophysics such as enhanced energy transfer, spectral stability, and strongly modified excited state lifetimes and blinking statistics. Here, we review the role of ligands in quantum dot applications and summarize some of our recent efforts probing energy and charge transfer in hybrid CdSe-OPV composite nanostructures

A Molecular Model For Intercellular Synchronization In The Mammalian Circadian Clock, Tsz-Leung To, Michael A. Henson, Erik D. Herzog, Francis J. Doyle Iii

Michael A Henson

The mechanisms and consequences of synchrony among heterogeneous oscillators are poorly understood in biological systems. We present a multicellular, molecular model of the mammalian circadian clock that incorporates recent data implicating the neurotransmitter vasoactive intestinal polypeptide (VIP) as the key synchronizing agent. The model postulates that synchrony arises amongcircadian neurons because they release VIP rhythmically on a daily basis and in response to ambient light. Two basic cell types, intrinsically rhythmic pacemakers and damped oscillators, are assumed to arise from a distribution of Period gene transcription rates. Postsynaptic neurons show time-of-day dependent responses to VIP binding through a signaling cascade …

Designing Model Systems For Enhanced Adhesion, Al Crosby

Alfred Crosby

Nature provides inspiration for enhanced control of adhesion through numerous examples ranging from geckos to jumping spiders. The primary strategy in these examples is the incorporation of patterns, specifically high-aspect-ratio topographic features, to ingeniously maximize adhesion forces while maintaining ease of release. Recently, considerable research efforts have been devoted toward the understanding, development, and optimization of synthetic analogues to these examples in nature. In this article, we provide insight into the mechanisms that lead to enhanced control of interfacial properties through patterning, the strategies that can be used for fabricating synthetic patterns, and an overview of experimental results that have …

The Optimal Pricing Of Pollution When Enforcement Is Costly, John K. Stranlund, Carlos A. Chavez, Mauricio G. Villena

John K. Stranlund

We consider the pricing of a uniformly mixed pollutant when enforcement is costly with a model of optimal, possibly firm-specific, emissions taxes and their enforcement. We argue that optimality requires an enforcement strategy that induces full compliance by every firm. This holds whether or not regulators have complete information about firms’ abatement costs, the costs of monitoring them for compliance, or the costs of collecting penalties from noncompliant firms. Moreover, ignoring several unrealistic special cases, optimality requires discriminatory emissions taxes except when regulators are unable to observe firms’ abatement costs, the costs of monitoring individual firms, or any firm-specific characteristic …

Implications Of D0- ¯D0 Mixing For New Physics, Eugene Golowich, Joanne Hewett, Sandip Pakvasa, Alexey A. Petrov

Eugene Golowich

We provide a comprehensive, up-to-date analysis of possible New Physics contributions to the mass difference ∆M_D in D^0- D ̅^0 mixing. We consider the most general low energy effective Hamiltonian and include leading order QCD running of effective operators. We then explore an extensive list of possible New Physics models that can generate these operators, which we organize as including Extra Fermions, Extra Gauge Bosons, Extra Scalars, Extra Space Dimensions and Extra Symmetries. For each model we place restrictions on the allowed parameter space using the recent evidence for observation of D meson mixing. In many scenarios, we find strong …

A Role For Huntingtin In Dynein/Dynactin-Mediated Vesicle Trafficking, Jennifer Ross, Juliane P. Caviston, Sheila M. Antony, Mariko Tokito, Erika L.F Holzbaur

Jennifer Ross

Cytoplasmic dynein is a multisubunit microtubule motor complex that, together with its activator, dynactin, drives vesicular cargo toward the minus ends of microtubules. Huntingtin (Htt) is a vesicle-associated protein found in both neuronal and nonneuronal cells that is thought to be involved in vesicular transport. In this study, we demonstrate through yeast two-hybrid and affinity chromatography assays that Htt and dynein intermediate chain interact directly; endogenous Htt and dynein coimmunoprecipitate from mouse brain cytosol. Htt RNAi in HeLa cells results in Golgi disruption, similar to the effects of compromising dynein/dynactin function. In vitro studies reveal that Htt and dynein are …

Athol Slaughterhouse Rises From The Ashes, Madeleine K. Charney

Madeleine K. Charney

Plans for rebuilding the Athol slaughterhouse destroyed by fire in 2006.

Social Control Of Brain Morphology In A Eusocial Mammal, Geert De Vries, M. M. Holmes, G. J. Rosen, C. L. Jordan, B. D. Goldman, N. G. Forger

Geert De Vries

Social status impacts reproductive behavior in diverse vertebrate species, but little is known about how it affects brain morphology. We explore this in the naked mole-rat, a species with the most rigidly organized reproductive hierarchy among mammals. Naked mole-rats live in large, subterranean colonies where breeding is restricted to a single female and small number of males. All other members of the colony, known as subordinates, are reproductively suppressed. Subordinates can become breeders if removed from the colony and placed with an opposite sex partner, but in nature most individuals never attain reproductive status. We examined the brains of breeding …

Cerebellar Activation During Discrete And Not Continuous Timed Movements: An Fmri Study, Rebecca M. C. Spencer, Timothy Verstynen, Matthew Brett, Richard Ivry

Rebecca M. C. Spencer

Individuals with cerebellar lesions are impaired in the timing of repetitive movements that involve the concatenation of discrete events such as tapping a finger. In contrast, these individuals perform comparably to controls when producing continuous repetitive movements. Based on this, we have proposed that the cerebellum plays a key role in event timing—the representation of the temporal relationship between salient events related to the movement (e.g., flexion onset or contact with a response surface). In the current study, we used fMRI to examine cerebellar activity during discrete and continuous rhythmic movements. Participants produced rhythmic movements with the index finger either …

On The Parameterization Dependence Of The Energy Momentum Tensor And The Metric, N. E. J. Bjerrum-Bohr, John Donoghue, Barry R. Holstein

John Donoghue

We use results by Kirilin to show that in general relativity the nonleading terms in the energy-momentum tensor of a particle depends on the parameterization of the gravitational field. While the classical metric that is calculated from this source, used to define the leading long-distance corrections to the metric, also has a parameteriztion dependence, it can be removed by a coordinate change. Thus the classical observables are parameterization independent. The quantum effects that emerge within the same calculation of the metric also depend on the parameterization and a full quantum calculation requires the inclusion of further diagrams. However, within a …

Utilizing A Multi-Technique, Multi-Taxa Approach To Monitoring Wildlife Passageways On The Bennington Bypass In Southern Vermont, Mark A. Bellis, Scott D. Jackson, Curtis R. Griffin, Paige S. Warren, Alan O. Thompson

Scott D. Jackson

Roadways affect wildlife habitat disproportionate to the area of land they occupy while impacting wildlife directly through direct loss of habitat, road mortality and disruption of movement. Roadways indirectly impact wildlife by isolating populations and disrupting gene flow and metapopulation dynamics. A variety of strategies have been used with mixed success to mitigate the impacts of transportation systems on wildlife. Underpasses are commonly used to facilitate movement of wildlife across roadways in Europe, Australia, Canada and the U.S. Through 2005, 460 terrestrial and 300 aquatic crossing structures have been identified throughout the United States but only a small portion of …