Life Sciences Commons^™

Accelerated Erosion Of Saltmarshes Infested By The Non-Native Burrowing Crustacean Sphaeroma Quoianum, Timothy Mathias Davidson, Catherine E. De Rivera

Environmental Science and Management Faculty Publications and Presentations

Lateral erosion of saltmarshes is affected by many abiotic and biotic factors. While abiotic factors are typically regarded as primary drivers of erosion, biotic influences such as burrowing or bioturbating taxa can also extensively modify the physical structure of this marine habitat. Many estuaries on the Pacific coast of North America have been invaded by populations of the burrowing non-native isopod Sphaeroma quoianum, which are thought to exacerbate the erosion of saltmarshes. We conducted a mensurative experiment to examine the relationship between populations of S. quoianum and lateral erosion rate of saltmarshes in Coos Bay, Oregon, USA. After 1 …

Caribbean Corals In Crisis: Record Thermal Stress, Bleaching, And Mortality In 2005, C. Mark Eakin, Jessica A. Morgan, Scott F. Heron, Tyler B. Smith, Gang Liu, Lorenzo Alvarez-Filip, Bart J. Baca, Erich Bartels, Carolina Bastidas, Claude Bouchon, Marilyn Brandt, Andrew W. Bruckner, Lucy Bunkley-Williams, Andrew Cameron, Billy D. Causey, Mark Chiappone, Tyler R. L. Christensen, M. James C. Crabbe, Owen Day, Elena De La Guardia, Guillermo Diaz-Pulido, Daniel Diresta, Diego L. Gil-Agudelo, David S. Gilliam, Robert N. Ginsburg, Shannon Gore, Hector M. Guzman, James C. Hendee, Edwin A. Hernandez-Delgado, Ellen Husain, Christopher F. G. Jeffrey, Ross J. Jones, Eric Jordan-Dahlgren, Les S. Kaufman, David I. Kline, Philip A. Kramer, Judith C. Lang, Diego Lirman, Jennie Mallela, Carrie Manfrino, Jean-Philippe Marechal, Ken Marks, Jennifer Mihaly, W. Jeff Miller, Erich M. Mueller, Erinn M. Muller, Carlos A. Orozco Toro, Hazel A. Oxenford, Daniel Ponce-Taylor, Norman Quinn, Kim B. Ritchie, Sebastian Rodriguez, Alberto Rodriguez Ramirez, Sandra Romano, Jameal F. Samhouri, Juan A. Sanchez, George P. Schmahl, Burton V. Shank, William J. Skirving, Sascha C. C. Steiner, Estrella Villamizar, Sheila M. Walsh, Cory Walter, Ernesto Weil, Ernest H. Williams, Kimberly Woody Roberson, Yusri Yusuf

Marine & Environmental Sciences Faculty Articles

Background: The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.

Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior …

Determining Optimal Storage Arrangements For Open Access Data Sets, As For Nsf Data Management Plan Requirements, David B. Lowe

Published Works

Document is a proposed draft of a decision tree to be used in determining what approach to take for making data available in order to comply with open access requirements for data management, as per National Science Foundation requirements.

Is Philosophy Dead? Far From It, Charles Weijer

Charles Weijer

No abstract provided.

Rotman Institute Opening, Joseph Rotman, Janice Deakin, Jane Maienschein, Charles Weijer, Philip Kitcher

Charles Weijer

No abstract provided.

Integrating Geographic Information Systems And Multi-Criteria Analysis To Assess Suitable Species And Plantation Sites: A Case Study Assessing Elaeocarpus Grandis And Gevillea Robusta Suitability On The Nsw North Coast, Kristin Den Exter

Dr Kristin den Exter

No abstract provided.

Comparison Of Bacteroides Human Markers For Pollution Diagnostics In Recreational Waters, Asli Aslan, Joan B. Rose

Environmental Health Sciences Faculty Presentations

This presentation was given during the Great Lakes Beach Association Annual Conference.

(1e,3e)-1,4-Bis(4-Methoxyphenyl)Buta1,3-Diene, Gopinathan Narayan, Nigam Rath, Suresh Das

Chemistry & Biochemistry Faculty Works

The title compound, C18H18O2, which exhibits blue emission in the solid state, is an inter­mediate in the preparation of liquid crystals and polymers. The mol­ecule is located on an inversion centre. In the crystal, mol­ecules are arranged in a herringbone motif.

(1e,3e)-1,4-Bis(4-Methoxyphenyl)Buta1,3-Diene, Gopinathan Narayan, Nigam P. Rath, Suresh Das

Nigam Rath

Functionalization Of Diamond And Its Application In High Performance Liquid Chromatography And Solid Phase Extraction, Gaurav Saini

Theses and Dissertations

The primary focus of my work was to chemically functionalize diamond as normal and reversed phases for solid phase extraction (SPE) and high performance liquid chromatography (HPLC). Diamond was functionalized with -NH2 groups via self-limiting adsorption of an amine-containing polymer, polyallylamine (PAAm), onto oxidized diamond particles. The chemical stability of these particles was improved by thermal curing or chemical crosslinking with 1,2,5,6-diepoxycyclooctane. The reversed phase material for SPE was synthesized by reacting amine-functionalized diamond particles with long chain alkyl and a perfluorinated isocyanate. Unlike commercially available silica, functionalized diamond particles were stable under extreme pH conditions (pH 0-14). Functionalized diamond …

Walking Box Ranch Planning And Design Quarterly Progress Report: Period Ending October 10, 2010, Margaret N. Rees

Walking Box Ranch

• UNLV Public Safety is assisting in identifying security methods needed to guarantee safety and security at the ranch after project completion. This effort will involve the assistance of Metro CPTED program officers as design proceeds.
• UNLV IT is determining the extent to which they can assist with networking and technology issues as project design moves forward. They may assist in identifying consultants to hire to assist with technology.
• We have solicited research/education proposals from UNLV faculty for projects to be initiated in the coming year. The goal is to provide seed funding for projects that will expand as the facilities …

Scoring Function To Predict Solubility Mutagenesis, Ye Tian, Christopher Deutsch, Bala Krishnamoorthy

Chemistry Faculty Publications and Presentations

Background: Mutagenesis is commonly used to engineer proteins with desirable properties not present in the wild type (WT) protein, such as increased or decreased stability, reactivity, or solubility. Experimentalists often have to choose a small subset of mutations from a large number of candidates to obtain the desired change, and computational techniques are invaluable to make the choices. While several such methods have been proposed to predict stability and reactivity mutagenesis, solubility has not received much attention. Results: We use concepts from computational geometry to define a three body scoring function that predicts the change in protein solubility due to …

Superoxide Does React With Peroxides: Direct Observation Of The Haber-Weiss Reaction In The Gas Phase, Stephen J. Blanksby, G. B. Ellison, V. M. Bierbaum, S. Kato

Stephen Blanksby

Reactions of superoxide with hydrogen peroxide and organic hydroperoxides are observed as efficient processes in the gas phase and yield products – including the ozonide anion – that are consistent with the one-electron reduction of the peroxide.

Investigation Of The Gas Phase Reactivity Of The 1-Adamantyl Radical Using A Distonic Radical Anion Approach, D. G. Harman, Stephen J. Blanksby

Stephen Blanksby

The gas phase reactions of the bridgehead 3-carboxylato-1-adamantyl radical anion were observed with a series of neutral reagents using a modified electrospray ionisation linear ion trap mass spectrometer. This distonic radical anion was observed to undergo processes suggestive of radical reactivity including radical-radical combination reactions, substitution reactions and addition to carbon-carbon double bonds. The rate constants for reactions of the 3-carboxylato-1-adamantyl radical anion with the following reagents were measured (in units 10 12 cm3 molecule 1 s 1): 18O2 (85±4), NO (38.4±0.4), I2 (50±50), Br2 (8±2), CH3SSCH3 (12±2), styrene (1.20±0.03), CHCl3 (H abstraction 0.41±0.06, Cl abstraction 0.65±0.1), CDCl3 (D abstraction …

The Lowest Singlet And Triplet States Of The Oxylallyl Diradical, David A. Hrovat, Stephen J. Blanksby, W C. Lineberger, Andrei Sanov, Luis Verlarde, Weston T. Borden, Daniel J. Goebbert, Adam J. Gianola, Xin Zhou, Stephanie M. Villano, Takatoshi Ichino

Stephen Blanksby

Photodetachment of the oxyallyl radical anion leads to formation of the oxyallyl diradical, an elusive transient molecule involved in many organic reactions. As described by W. C. Lineberger et al. in their Communication on page 8509 ff., the photoelectron spectrum reveals that the oxyallyl ground state is singlet and the lowest triplet state is only 55 meV higher in energy. The spectral profile indicates that the planar singlet state is the transition state for ringopening of cyclopropanone, whilst the CCC bending motion is activated upon photodetachment to the triplet state.

Online Ozonolysis Methods For The Determination Of Double Bond Position In Unsaturated Lipids, Michael Thomas, Todd W. Mitchell, Stephen J. Blanksby

Stephen Blanksby

Modern lipidomics relies heavily on mass spectrometry for the structural characterization and quantification of lipids of biological origins. Structural information is gained by tandem mass spectrometry (MS/MS) whereby lipid ions are fragmented to elucidate lipid class, fatty acid chain length, and degree of unsaturation. Unfortunately, however, in most cases double bond position cannot be assigned based on MS/MS data alone and thus significant structural diversity is hidden from such analyses. For this reason, we have developed two online methods for determining double bond position within unsaturated lipids; ozone electrospray ionization mass spectrometry (OzESI-MS) and ozone-induced dissociation (OzID). Both techniques utilize …

Prenylated Alkylbisphenols From Grevillea Whiteana, Stephen J. Blanksby, Hao Wang, Paul I. Forster, David N. Leach, Peter G. Waterman, Michael C. Thomas

Stephen Blanksby

Eleven new bisresorcinols including four mixtures each of two isomers and one resorcinol/phloroglucinol derivative, together with five known resorcinols have been isolated from the ethyl acetate extract of sterns of Grevillea whiteana. The new Compounds were identified as 4-(3-hydroxy-3-methylbutyl)grebustol-B (10a), 4'-(3-hydroxy-3-methylbutyl)grebustol-B (10b), 4-(4-hydroxy-3-methylbutyl)grebustol-B (2a) and 4'-(4-hydroxy-3-methylbutyl) rebustol-B (2b), 2,2-dimethyldihydropyrano grebustol-B (11a) and iso-2,2-dimethyldihydropyranogrebustol-B (11b), 2,2-dimethyl-3 xi-hydroxydihydropyranogrebustol-B (7a) and iso-2,2-dimethyl-3 xi-hydroxydihydropyranogrebustol-B (7b), 15-(2-(4-hydroxy-3-methylbutyl)-resorcinol-5-yl)-1-(phloroglucinolyl )-9(Z)pentadecen-one (whiteanone) (4), 5,5'-(hexadecan-diyl)bisresorcinol (12) and 2-methyl-5,5'-(8(Z)hexadecen-1,16-diyl)bisresorcinol (9). This is the first record of pyranobisresorcinols in the genus and the first report of a phloroglucinol terminal Phenolic unit in any Grevillea species.

Identification Of Abundant Alkyl Ether Glycerophospholipids In The Human Lens By Tandem Mass Spectrometry Techniques, Roger J. Truscott, Jane Deeley, Todd W. Mitchell, Michael Thomas, Stephen J. Blanksby

Stephen Blanksby

Previous studies have shown that the human lens contains glycerophospholipids with ether linkages. These lipids differ from conventional glycerophospholipids in that the sn-1 substituent is attached to the glycerol backbone via an 1-O-alkyl or an 1-O-alk-1'-enyl ether rather than an ester bond. The present investigation employed a combination of collision-induced dissociation (CID) and ozone-induced dissociation (OzID) to unambiguously distinguish such 1-O-alkyl and 1-O-alk-1'-enyl ethers. Using these methodologies the human lens was found to contain several abundant 1-O-alkyl glycerophos-phoethanolamines, including GPEtn(16:0e/9Z-18:1), GPEtn(11Z-18:1e/9Z-18:1), and GPEtn(18:0e/9Z-18:1), as well as a related series of unusual 1-O-alkyl glycerophosphoserines, including GPSer(16:0e/9Z-18:1), GPSer(11Z-18:1e/9Z-18:1), GPSer(18:0e/9Z-18:1) that to our …

Trapping Of A Tert-Adamantyl Peroxyl Radical In The Gas Phase, D. G. Harman, Stephen J. Blanksby

Stephen Blanksby

A bridgehead adamantyl peroxyl radical has been prepared and isolated in the gas phase by the reaction of a distonic radical anion with dioxygen in a quadrupole ion-trap mass spectrometer.

Fragmentation Pathways Of 2,3-Dimethyl-2,3-Dinitrobutane Cations In The Gas Phase, Martin Paine, Benjamin Kirk, Simon Ellis-Steinborner, Stephen J. Blanksby

Stephen Blanksby

2,3-Dimethyl-2,3-dinitrobutane (DMNB) is an explosive taggant added to plastic explosives during manufacture making them more susceptible to vapour-phase detection systems. In this study, the formation and detection of gas-phase [M+H](+), [M+Li](+), [M+NH4](+) and [M+Na](+) adducts of DMNB was achieved using electrospray ionisation on a triple quadrupole mass spectrometer. The [M+H](+) ion abundance was found to have a strong dependence on ion source temperature, decreasing markedly at source temperatures above 50 degrees C. In contrast, the [M+Na](+) ion demonstrated increasing ion abundance at source temperatures up to 105 degrees C. The relative susceptibility of DMNB adduct ions toward dissociation was investigated …

Ion-Molecule Reactions Of O,S-Dimethyl Methylphosphonothioate: Evidence For Intramolecular Sulfur Oxidation During Vx Perhydrolysis, Jilliarne Williams, Martin Paine, Stephen J. Blanksby, Michael L. Rogers, Andrew M. Mcanoy

Stephen Blanksby

The alkaline perhydrolysis of the nerve agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) was investigated by studying the ion-molecule reactions of HOO- with O,S-dimethyl methylphosphonothioate in a modified linear ion-trap mass spectrometer. In addition to simple proton transfer, two other abundant product ions are observed at m/z 125 and 109 corresponding to the S-methyl methylphosphonothioate and methyl methylphosphonate anions, respectively. The structure of these product ions is demonstrated by a combination of collision-induced dissociation and isotope-labeling experiments that also provide evidence for their formation by nucleophilic reaction pathways, namely, (i) S(N)2 at carbon to yield the S-methyl methylphosphonothioate anion and (ii) nucleophilic …

Tandem Mass Spectrometry Of Deprotonated Iodothyronines, A. M. Couldwell, M. C. Thomas, Todd Mitchell, A. Hulbert, Stephen J. Blanksby

Stephen Blanksby

In order to assist with the development of more selective and sensitive methods for thyroid hormone analysis the [M-H]– anions of the iodothyronines; T4, T3, rT3, (3,5)-T2 and the non-iodinated thyronine (T0) have been generated by negative ion electrospray mass spectrometry. Tandem mass spectra of these ions were recorded on a triple quadrupole mass spectrometer and show a strong analogy with the fragmentation pathways of the parent compound, tyrosine. All iodothyronines also show significant abundances of the iodide anion in their tandem mass spectra, which represents an attractive target for MRM analysis, given that iodothyronines are the only iodine bearing …

A Comparison Of The Gas Phase Acidities Of Phospholipid Headgroups:Experimental And Computational Studies, M. C. Thomas, Todd Mitchell, Stephen J. Blanksby

Stephen Blanksby

Proton-bound dimers consisting of two glycerophospholipids with different headgroups were prepared using negative ion electrospray ionization and dissociated in a triple quadrupole mass spectrometer. Analysis of the tandem mass spectra of the dimers using the kinetic method provides, for the first time, an order of acidity for the phospholipid classes in the gas phase of PE < PA << PG < PS < PI. Hybrid density functional calculations on model phospholipids were used to predict the absolute deprotonation enthalpies of the phospholipid classes from isodesmic proton transfer reactions with phosphoric acid. The computational data largely support the experimental acidity trend, with the exception of …

Ion-Molecule Reactions Reveal Facile Radical Migration In Peptides, Stephen J. Blanksby, Benjamin N. Moore, Ryan R. Julian

Stephen Blanksby

Ion-molecule reactions between molecular oxygen and peptide radicals in the gas phase demonstrate that radical migration occurs easily within large biomolecules without addition of collisional activation energy.

Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Symbioses between microbes and animals are ubiquitous, yet little is known about the intricate mechanisms maintaining such associations. In an emerging mutualistic model system, insect-pathogenic bacteria Photorhabdus and their insect-parasitic nematode partner Heterorhabditis, we found that the bacteria undergo major transcriptional reshaping in the nematode intestine. Besides general starvation mechanisms, the bacteria induce cellular acidification to slow down growth, switch to pentose phosphate pathway to overcome oxidative stress and nutrition limitation, and shed motility but develop biofilm to persist in the nematode intestine until being released into the insect hemolymph. These findings demonstrate how the symbiotic bacteria reduce their …

Solving The Low Dimensional Smoluchowski Equation With A Singular Value Basis Set, Gregory E. Scott, Martin Gruebele

Chemistry and Biochemistry

Reaction kinetics on free energy surfaces with small activation barriers can be computed directly with the Smoluchowski equation. The procedure is computationally expensive even in a few dimensions. We present a propagation method that considerably reduces computational time for a particular class of problems: when the free energy surface suddenly switches by a small amount, and the probability distribution relaxes to a new equilibrium value. This case describes relaxation experiments. To achieve efficient solution, we expand the density matrix in a basis set obtained by singular value decomposition of equilibrium density matrices. Grid size during propagation is reduced from (100–1000) …

The Amazon Frontier Of Land-Use Change: Croplands And Consequences For Greenhouse Gas Emissions, Gillian L. Galford, Jerry Melillo, John F. Mustard, Carlos E.P. Cerri, Carlos C. Cerri

Rubenstein School of Environment and Natural Resources Faculty Publications

The Brazilian Amazon is one of the most rapidly developing agricultural frontiers in the world. The authors assess changes in cropland area and the intensification of cropping in the Brazilian agricultural frontier state of Mato Grosso using remote sensing and develop a greenhouse gas emissions budget. The most common type of intensification in this region is a shift from single-to double-cropping patterns and associated changes in management, including increased fertilization. Using the enhanced vegetation index (EVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, the authors created a green-leaf phenology for 2001-06 that was temporally smoothed with a wavelet filter. …

Balancing Limiting Factors & Economic Drivers For Sustainable Midwestern Us Agricultural Residue Feedstock Supplies, Wally W. Wilhelm, J. Richard Hess, Douglas L. Karlen, Jane M. F. Johnson, David J. Muth Jr., John M. Baker, Hero T. Gollany, Jeff M. Novak, Diane E. Scott, Gary E. Varvel

David J. Muth

Advanced biofuels will be developed using cellulosic feedstock rather than grain or oilseed crops that can also be used for food and feed. To be sustainable, these new agronomic production systems must be economically viable without degrading the soil and other natural resources. This review examines six agronomic factors that collectively define many of the limits and opportunities for harvesting crop residue for biofuel feedstock in the midwestern United States. The limiting factors include soil organic carbon, wind and water erosion, plant nutrient balance, soil water and temperature dynamics, soil compaction, and off-site environmental impacts. These are discussed in relationship …

Hrc Enews — 2010 Fall, Megan K. Svarz

Publications (HRC)

This issue contains staff accomplishments and announcements, event listings, and a "new faces" listing for new staff, affiliates, and researchers.

Unlv Magazine, Tony Allen, Shane Bevell, Donna Mcaleer, Ched Whitney, Cate Weeks

UNLV Magazine

No abstract provided.