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Full-Text Articles in Physical Sciences and Mathematics

The Fossil Fuel Energy Industry Vs. The Endangered Species Act, Cody Willnerd Dec 2017

The Fossil Fuel Energy Industry Vs. The Endangered Species Act, Cody Willnerd

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

It was several weeks ago that the Congressional Republicans made a push to reform the landmark Endangered Species Act to make it more friendly to landowners and fossil fuel industries. They would do this by releasing species earlier on the ESA list than before and instead focus on species that are in the greatest of need of attention. The reform would also have agencies focus on the economic costs to deny listings of species, require the agency to listen towards states concerns, and limit payouts for attorney fees in ESA litigations. This would be incredibly damaging to many species that …


Energy Star Tax Holiday Simply Advertising Gimmick, Lauren Klaasmeyer Dec 2017

Energy Star Tax Holiday Simply Advertising Gimmick, Lauren Klaasmeyer

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

In January of this year, Senator Harr introduced Legislative Bill 325. From 12:01 A.M. on the first Friday of October through midnight of the first Sunday, all Energy Star products less than $1500 will be exempt from sales and use taxes. The special interest group, Nebraska Retail Federation, proposed the idea to Senator Harr. There was no move to advance the bill last session, so it could be brought back up this coming session or amended to another bill. When speaking with people at the capitol, it was said that the main reason it was not advanced was because of …


The Tax That Will Actually Do Something Is Not In The Current Bill, Steven Kirchner Dec 2017

The Tax That Will Actually Do Something Is Not In The Current Bill, Steven Kirchner

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

If we are going to be talking about tax reform, we should be talking about solutions that will actually solve a problem. The combustion of fossil fuels has much more than environmental implications. Burning fossil fuels is a blatant catastrophe for our entire economic system. The current American energy market is entirely reliant on fossil fuels (coal, oil, and natural gas). Negative externalities have flooded the American economic system because of the combustion of fossil fuels. A negative externality is a cost that indirectly affects someone outside of the economic transaction. That third party entity must bear the burden of …


Recent Increase In Deadly Storms, Westin Longacre Dec 2017

Recent Increase In Deadly Storms, Westin Longacre

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

These last few years have hit us with some devastating storms that continue to wreck havoc on our earth. We have been hit with multiple storms that are so strong that they are predicted to happen every 50 years, so is God punishing us? Or do we have something to do with this? This issue should be a huge concern to us because who knows how many more of these devastating storms we can handle. When looking at why these tragic storms are happening more frequently the main factor that is leading to these events is the increase in atmospheric …


Chemistry And Biochemistry News, Georgia Southern University Dec 2017

Chemistry And Biochemistry News, Georgia Southern University

Department of Chemistry and Biochemistry News (2015-2023)

  • SERMACS 2017
  • Simpo Akech Defends her Master's Thesis


Wind Is Nebraska’S Future, With Or Without The Clean Power Plan, Megan Pamperin Dec 2017

Wind Is Nebraska’S Future, With Or Without The Clean Power Plan, Megan Pamperin

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

The Clean Power Plan was issued in October 2015. President Trump called for a review of the plan this March and on October 16th, 2017 the EPA released a proposal to repeal it. The Clean Power Plan would have reduced Nebraska’s state emissions to 22,250,000 tons of carbon dioxide by 2024, down by about 5 million tons compared to 2012 emissions.1 The new projection for 2020 without the plan is 34 million tons of CO2 emitted.

Coal and other fossil fuel energy sources are the main culprits of these carbon emissions, and here in Nebraska coal …


Matlab Processing Scripts To Accompany Spatially Resolved Measurements Of Crosslinking In Uv-Curable Coatings Using Single-Sided Nmr, Madeline Brass, Frances Jude Morin, Tyler Meldrum Dec 2017

Matlab Processing Scripts To Accompany Spatially Resolved Measurements Of Crosslinking In Uv-Curable Coatings Using Single-Sided Nmr, Madeline Brass, Frances Jude Morin, Tyler Meldrum

Data

These Matlab scripts are used to import CPMG data collected using a Kea spectrometer (through the program Prospa), and to process each echo using the Fourier transformation. This provides spatially resolved NMR relaxation data that can be fitted or subjected to inverse Laplace transformation (not provided) to characterize relaxation at different positions within a sample.


Conductivity, Temperature And Depth (Ctd) Data For Deepend Stations, Cruise Dp04, August 2016, David English, Chuanmin Hu, April Cook, Tracey Sutton Dec 2017

Conductivity, Temperature And Depth (Ctd) Data For Deepend Stations, Cruise Dp04, August 2016, David English, Chuanmin Hu, April Cook, Tracey Sutton

DEEPEND Datasets

Conductivity, temperature and depth data from the ship's CTD, which was deployed at each of the DEEPEND stations. Depth of cast was variable, but extended from near-surface waters to below the euphotic zone. This data was used in the assessment of the water column's vertical structure, and for comparison with physical models. Data were collected on cruise DP04 in August, 2016.


Anaerobic Digestion In Nebraska, Anthony Leapley Dec 2017

Anaerobic Digestion In Nebraska, Anthony Leapley

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Climate change is a global crisis that can be fought by all locally. Nebraska is my home, and it’s one of nine states in the U.S. in which cows outnumber humans. Statistically, there are three cows for every person (1,868,516 humans to 6,150,000 cows). While we have fewer humans than cows, it’s not hard to understand that we rank very low in CO2 emissions when ranking all states in the country. However, our emission of the more potent greenhouse gas CH4, or methane, is significantly higher. Methane is released by cows via gas and manure, and it’s causing serious implications …


Structural Evidence Of A Major Conformational Change Triggered By Substrate Binding In Dape Enzymes: Impact On The Catalytic Mechanism, Boguslaw Nocek, Cory Reid, Anna Starus, Tahirah Heath, David Bienvenues, Jerzy Osipiuk, Robert Jedrzeczak, Andrzej Joachimiak, Daniel P. Becker Ph.D., Richard C. Holz Dec 2017

Structural Evidence Of A Major Conformational Change Triggered By Substrate Binding In Dape Enzymes: Impact On The Catalytic Mechanism, Boguslaw Nocek, Cory Reid, Anna Starus, Tahirah Heath, David Bienvenues, Jerzy Osipiuk, Robert Jedrzeczak, Andrzej Joachimiak, Daniel P. Becker Ph.D., Richard C. Holz

Chemistry: Faculty Publications and Other Works

The X-ray crystal structure of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase from Haemophilus influenzae (HiDapE) bound by the products of hydrolysis, succinic acid and l,l-DAP, was determined at 1.95 Å. Surprisingly, the structure bound to the products revealed that HiDapE undergoes a significant conformational change in which the catalytic domain rotates ∼50° and shifts ∼10.1 Å (as measured at the position of the Zn atoms) relative to the dimerization domain. This heretofore unobserved closed conformation revealed significant movements within the catalytic domain compared to that of wild-type HiDapE, which results in effectively closing off access to …


Encoding Lexicographical Ordering Constraints In Sat, Wenting Zhao Dec 2017

Encoding Lexicographical Ordering Constraints In Sat, Wenting Zhao

Honors Projects

Symmetry occurs in many constraint satisfaction problems, and it is important to deal with it efficiently and effectively, as it often leads to an exponential number of isomorphic assignments. Symmetric rows and columns in matrices are an important class of symmetries in constraint programming. In this work, we develop a new SAT encoding for partial lexicographical ordering constraints to break symmetries in such places. We also survey all the previous complete lex-leader encodings in literature and translate them into SAT encodings. We perform experimental analysis on how these lex-leader constraints impact the solving of Balanced Incomplete Block Design (BIBD) instances. …


Reconstructing Results From Voting Theory Using Linear Algebra, Brian Camara Dec 2017

Reconstructing Results From Voting Theory Using Linear Algebra, Brian Camara

Honors Program Theses and Projects

For many undergraduate students, achieving an understanding of upper-level mathematics can be extremely challenging. For us, it helps to connect these new concepts with material we are familiar with. This will be the central theme of this thesis. We will introduce some basic components of algebraic voting theory, along with briey discussing how (Daugherty, Eustis, Minton, & Orrison, 2009) used representation theory to achieve their results. We will then provide an alternative proof to the main result of the (Daugherty et al., 2009) article using linear algebra, which should be much more familiar to my peers. We will carry out …


Recycling Clean Energy, Amanda Vaughn Dec 2017

Recycling Clean Energy, Amanda Vaughn

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Nuclear energy is one of the cleanest sources of energy available. It does not produce carbon dioxide as the beta decay of Uranium is an exothermic spontaneous process that produces helium. Unfortunately, nuclear waste storage is a large problem in the United States, the cost of maintaining the waste storage facilities alone is 46.7 billion dollars. There is the constant threat of leaks and contaminated water leaking into drinking supplies. Then there is the danger of the current geological storage tanks lasting longer than humanity and spoiling the future environment as current nuclear waste takes millions of years to decompose …


The Effect Of Time, Roasting Temperature, And Grind Size On Caffeine And Chlorogenic Acid Concentrations In Cold Brew Coffee, Niny Z. Rao, Megan Fuller Dec 2017

The Effect Of Time, Roasting Temperature, And Grind Size On Caffeine And Chlorogenic Acid Concentrations In Cold Brew Coffee, Niny Z. Rao, Megan Fuller

College of Humanities and Sciences Faculty Papers

The extraction kinetics and equilibrium concentrations of caffeine and 3-chlorogenic acid (3-CGA) in cold brew coffee were investigated by brewing four coffee samples (dark roast/medium grind, dark roast/coarse grind, medium roast/medium grind, medium roast/coarse grind) using cold and hot methods. 3-CGA and caffeine were found at higher concentrations in cold brew coffee made with medium roast coffees, rather than dark roast. The grind size did not impact 3-CGA and caffeine concentrations of cold brew samples significantly, indicating that the rate determining step in extraction for these compounds did not depend on surface area. Caffeine concentrations in cold brew coarse grind …


Atomistic Simulations And Network-Based Modeling Of The Hsp90-Cdc37 Chaperone Binding With Cdk4 Client Protein: A Mechanism Of Chaperoning Kinase Clients By Exploiting Weak Spots Of Intrinsically Dynamic Kinase Domains, John Czemeres, Kurt Buse, Gennady M. Verkhivker Dec 2017

Atomistic Simulations And Network-Based Modeling Of The Hsp90-Cdc37 Chaperone Binding With Cdk4 Client Protein: A Mechanism Of Chaperoning Kinase Clients By Exploiting Weak Spots Of Intrinsically Dynamic Kinase Domains, John Czemeres, Kurt Buse, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A fundamental role of the Hsp90 and Cdc37 chaperones in mediating conformational development and activation of diverse protein kinase clients is essential in signal transduction. There has been increasing evidence that the Hsp90-Cdc37 system executes its chaperoning duties by recognizing conformational instability of kinase clients and modulating their folding landscapes. The recent cryo-electron microscopy structure of the Hsp90-Cdc37- Cdk4 kinase complex has provided a framework for dissecting regulatory principles underlying differentiation and recruitment of protein kinase clients to the chaperone machinery. In this work, we have combined atomistic simulations with protein stability and network-based rigidity decomposition analyses to characterize dynamic …


Remote Sensing Of Forests Using Discrete Return Airborne Lidar, Hamid Hamraz, Marco A. Contreras Dec 2017

Remote Sensing Of Forests Using Discrete Return Airborne Lidar, Hamid Hamraz, Marco A. Contreras

Forestry and Natural Resources Faculty Publications

Airborne discrete return light detection and ranging (LiDAR) point clouds covering forested areas can be processed to segment individual trees and retrieve their morphological attributes. Segmenting individual trees in natural deciduous forests, however, remained a challenge because of the complex and multi-layered canopy. In this chapter, we present (i) a robust segmentation method that avoids a priori assumptions about the canopy structure, (ii) a vertical canopy stratification procedure that improves segmentation of understory trees, (iii) an occlusion model for estimating the point density of each canopy stratum, and (iv) a distributed computing approach for efficient processing at the forest level. …


Gw170608: Observation Of A 19 Solar-Mass Binary Black Hole Coalescence, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, Marc Favata, Shaon Ghosh, Rodica Martin Dec 2017

Gw170608: Observation Of A 19 Solar-Mass Binary Black Hole Coalescence, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, Marc Favata, Shaon Ghosh, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

On 2017 June 8 at 02:01:16.49 UTC, a gravitational-wave (GW) signal from the merger of two stellar-mass blackholes was observed by the two Advanced Laser Interferometer Gravitational-Wave Observatory detectors with anetwork signal-to-noise ratio of 13. This system is the lightest black hole binary so far observed, with componentmasses of 12+7-2M⊙7+2-2 (90% credible intervals). These lie in the range of measured black hole masses inlow-mass X-ray binaries, thus allowing us to compare black holes detected through GWs with electromagneticobservations. The source's luminosity distance is 340+140-140corresponding to redshift -0.07+0.03003. We verify thatthe signal waveform is consistent with the predictions of general relativity.


The Architecture Of The Gw Ori Young Triple-Star System And Its Disk: Dynamical Masses, Mutual Inclinations, And Recurrent Eclipses, I. Czekala, S. M. Andrews, G. Torres, J. E. Rodriguez, Eric L.N. Jensen, K. G. Stassun, D. W. Latham, D. J. Wilner, M. A. Gully-Santiago, K. N. Grankin, M. B. Lund, R. B. Kuhn, D. J. Stevens, R. J. Siverd, D. James, B. S. Gaudi, B. J. Shappee, T. W.-S. Holoien Dec 2017

The Architecture Of The Gw Ori Young Triple-Star System And Its Disk: Dynamical Masses, Mutual Inclinations, And Recurrent Eclipses, I. Czekala, S. M. Andrews, G. Torres, J. E. Rodriguez, Eric L.N. Jensen, K. G. Stassun, D. W. Latham, D. J. Wilner, M. A. Gully-Santiago, K. N. Grankin, M. B. Lund, R. B. Kuhn, D. J. Stevens, R. J. Siverd, D. James, B. S. Gaudi, B. J. Shappee, T. W.-S. Holoien

Physics & Astronomy Faculty Works

We present spatially and spectrally resolved Atacama Large Millimeter/submillimeter Array (ALMA) observations of gas and dust orbiting the pre-main-sequence hierarchical triple-star system GW Ori. A forward modeling of the ¹³CO and C¹8O J = 2–1 transitions permits a measurement of the total stellar mass in this system, 5.29 ± 0.09 M, and the circumtriple disk inclination, 137 fdg 6 ± 2 fdg 0. Optical spectra spanning a 35 yr period were used to derive new radial velocities and, coupled with a spectroscopic disentangling technique, revealed that the A and B components of GW Ori form a …


Gis Data: 2016 Chesapeake Bay Sav Coverage, Virginia Institute Of Marine Science, Sav Data Administrator Dec 2017

Gis Data: 2016 Chesapeake Bay Sav Coverage, Virginia Institute Of Marine Science, Sav Data Administrator

Data

Abstract: The 2015 Chesapeake Bay SAV Coverage was mapped from digital multispectral imagery with a 25cm GSD to assess water quality in the Bay. Each area of SAV was interpreted from the rectified imagry and classified into one of four density classes by the percentage of cover. The SAV beds were entered into an SDE GIS fetaure class using the quality control procedures documented below. The dataset contains all SAV areas that were identified from the areas flown. Some areas that are presumed to contain no SAV were not flown. Some small beds, particularly along narrow tributaries may not have …


Fossil Fuel Subsidies In America, Jackson Cutsor Dec 2017

Fossil Fuel Subsidies In America, Jackson Cutsor

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Two of the most controversial topics in American politics today are climate change and the federal budget. Subsidies for energy generation fit into both categories.

Subsidies given to the energy industry artificially decrease the price of energy and electricity. Low energy prices help stimulate the market, however, the negative externalities like the social cost of carbon and political corruption are not taken into consideration.

Subsidies can come in many forms including: failure to impose external costs, tax breaks, and low interest loans. Even without imposing the social cost of carbon a removal of fossil fuel energy subsidies can have a …


Pulsar J1411+2551: A Low-Mass Double Neutron Star System, J. G. Martinez, K. Stovall, P. C.C. Freire, J. S. Deneva, T. M. Tauris, A. Ridolfi, N. Wex, F. A. Jenet, M. A. Mclaughlin, M. Bagchi Dec 2017

Pulsar J1411+2551: A Low-Mass Double Neutron Star System, J. G. Martinez, K. Stovall, P. C.C. Freire, J. S. Deneva, T. M. Tauris, A. Ridolfi, N. Wex, F. A. Jenet, M. A. Mclaughlin, M. Bagchi

Physics and Astronomy Faculty Publications and Presentations

In this work, we report the discovery and characterization of PSR J1411+2551, a new binary pulsar discovered in the Arecibo 327 MHz Drift Pulsar Survey. Our timing observations of the radio pulsar in the system span a period of about 2.5 years. This timing campaign allowed a precise measurement of its spin period (62.4 ms) and its derivative (9.6 ±0.7) ×10 -20 s s -1 ; from these, we derive a characteristic age of >9.1 Gyr and a surface magnetic field strength of <2.6 ×10 9 G. These numbers indicate that this pulsar was mildly recycled by accretion of matter from the progenitor of the companion star. The system has an eccentric (e =0.17) 2.61 day orbit. This eccentricity allows a highly significant measurement of the rate of advance of periastron, . Assuming general relativity accurately describes the orbital motion, this implies a total system mass M =2.538 ±0.022 M o . The minimum companion mass is 0.92 M o and the maximum pulsar mass is 1.62 M o . The large companion mass and the orbital eccentricity suggest that PSR J1411+2551 is a double neutron star system; the lightest known to date including the DNS merger GW170817. Furthermore, the relatively low orbital eccentricity and small proper motion limits suggest that the second supernova had a relatively small associated kick; this and the low system mass suggest that it was an ultra-stripped supernova.


Mitigating Projected Impacts Of Climate Change And Building Resiliency Through Permaculture: A Community ‘Bee Inspired Gardens’ Movement In The Desert Southwest, Usa, Roslynn Brain, Jeffrey Adams, Jeremy Lynch Dec 2017

Mitigating Projected Impacts Of Climate Change And Building Resiliency Through Permaculture: A Community ‘Bee Inspired Gardens’ Movement In The Desert Southwest, Usa, Roslynn Brain, Jeffrey Adams, Jeremy Lynch

Environment and Society Faculty Publications

Permaculture, an integrative design process creating resilient and productive landscapes and communities, can serve as a useful mitigation tool for projected climate change impacts. In the United States, the desert southwest town of Moab, Utah, has employed permaculture design in a community initiative called ‘Bee Inspired Gardens.’ This initiative has harnessed social capital to create resilient landscapes demonstrating pollinator health, water conservation, and perennial food and forage systems. Bee Inspired Gardens have been designed at a University, middle school, charter school, Bureau of Land Management property, hotel, public park, environmental education non-profit, and more. Community members are now harvesting fruit …


Virtual Reality As A Training Tool To Treat Physical Inactivity In Children, Adam W. Kiefer, David Pincus, Michael J. Richardson, Gregory D. Myer Dec 2017

Virtual Reality As A Training Tool To Treat Physical Inactivity In Children, Adam W. Kiefer, David Pincus, Michael J. Richardson, Gregory D. Myer

Psychology Faculty Articles and Research

Lack of adequate physical activity in children is an epidemic that can result in obesity and other poor health outcomes across the lifespan. Physical activity interventions focused on motor skill competence continue to be developed, but some interventions, such as neuromuscular training (NMT), may be limited in how early they can be implemented due to dependence on the child’s level of cognitive and perceptual-motor development. Early implementation of motor-rich activities that support motor skill development in children is critical for the development of healthy levels of physical activity that carry through into adulthood. Virtual reality (VR) training may be beneficial …


Industrial-Age Doubling Of Snow Accumulation In The Alaska Range Linked To Tropical Ocean Warming, Dominic Winski, Erich Osterberg, David Ferris, Karl Kreutz, Cameron Wake, Seth Campbell, Robert Hawley, Samuel Roy, Sean Birkel, Douglas Introne, Michael Handley Dec 2017

Industrial-Age Doubling Of Snow Accumulation In The Alaska Range Linked To Tropical Ocean Warming, Dominic Winski, Erich Osterberg, David Ferris, Karl Kreutz, Cameron Wake, Seth Campbell, Robert Hawley, Samuel Roy, Sean Birkel, Douglas Introne, Michael Handley

Dartmouth Scholarship

Future precipitation changes in a warming climate depend regionally upon the response of natural climate modes to anthropogenic forcing. North Pacific hydroclimate is dominated by the Aleutian Low, a semi-permanent wintertime feature characterized by frequent low-pressure conditions that is influenced by tropical Pacific Ocean temperatures through the Pacific-North American (PNA) teleconnection pattern. Instrumental records show a recent increase in coastal Alaskan precipitation and Aleutian Low intensification, but are of insufficient length to accurately assess low frequency trends and forcing mechanisms. Here we present a 1200-year seasonally- to annually-resolved ice core record of snow accumulation from Mt. Hunter in the Alaska …


Redesign Of The Bridgewater State University Website, Jordan Rossetti Dec 2017

Redesign Of The Bridgewater State University Website, Jordan Rossetti

Honors Program Theses and Projects

In this thesis, I studied human-computer interaction (HCI), analyzed the usability of the Bridgewater State University website, and redesigned it guided by HCI principles and user experiments. A goal of the project is to apply suggestions from HCI research to the usability analysis of an existing website. I redesigned the website based on this analysis and by conducting user experiments compare the redesign against the existing BSU website. With this project, I redesigned a website that demonstrably improves users’ success at information seeking and navigation while reducing frustration and hassle compared to the current Bridgewater State University (BSU) website. This …


Developing A Virtual Reality Android Application To Remote Explore A Room, Jamie Nelson Dec 2017

Developing A Virtual Reality Android Application To Remote Explore A Room, Jamie Nelson

Honors Program Theses and Projects

Virtual reality is a rapidly growing area of research. Many scholars are emphasizing its importance and creators are designing cheaper equipment to acquire it. The purpose of this research was to create a simple virtual reality mobile application that allows the user to explore a room. For this thesis, we created a robot and, with the help from a fellow researcher, we optimized the robot for this specific task. We programed the robot to move forward in small increments and to spin a platform holding a Go Pro camera. The camera sends a live stream video to an Android mobile …


Changes In Enzyme Structural Dynamics Studied By Hydrogen Exchange-Mass Spectrometry: Ligand Binding Effects Or Catalytically Relevant Motions?, Courtney S Fast, Siavash Vahidi, Lars Konermann Dec 2017

Changes In Enzyme Structural Dynamics Studied By Hydrogen Exchange-Mass Spectrometry: Ligand Binding Effects Or Catalytically Relevant Motions?, Courtney S Fast, Siavash Vahidi, Lars Konermann

Chemistry Publications

It is believed that enzyme catalysis is facilitated by conformational dynamics of the protein scaffold that surrounds the active site, yet the exact nature of catalytically relevant protein motions remains largely unknown. Hydrogen/deuterium exchange (HDX) mass spectrometry (MS) reports on backbone H-bond fluctuations. HDX/MS thus represents a promising avenue for probing the relationship between enzyme dynamics and catalysis. A seemingly straightforward strategy for such studies involves comparative measurements during substrate turnover and in the resting state. We examined the feasibility of this approach using rabbit muscle pyruvate kinase (rM1-PK) which catalyzes the conversion of phosphoenolpyruvate and Mg-ADP to pyruvate and …


Testing The Underlying Chemical Principles Of The Biotic Ligand Model (Blm) To Marine Copper Systems: Measuring Copper Speciation Using Fluorescence Quenching, Tara N. Tait, James C. Mcgeer, Scott Smith Dec 2017

Testing The Underlying Chemical Principles Of The Biotic Ligand Model (Blm) To Marine Copper Systems: Measuring Copper Speciation Using Fluorescence Quenching, Tara N. Tait, James C. Mcgeer, Scott Smith

Chemistry Faculty Publications

Speciation of copper in marine systems strongly influences the ability of copper to cause toxicity. Natural organic matter (NOM) contains many binding sites which provides a protective effect on copper toxicity. The purpose of this study was to characterize copper binding with NOM using fluorescence quenching techniques. Fluorescence quenching of NOM with copper was performed on nine sea water samples. The resulting stability con- stants and binding capacities were consistent with literature values of marine NOM, show- ing strong binding with log K values from 7.64 to 10.2 and binding capacities ranging from 15 to 3110 nmole mg C −1 …


The Role Of Catalytic Residue PKA On The Hydrolysis/Transglycosylation Partition In Family 3 Β-Glucosidases, Inacrist Geronimo, Christina M. Payne, Mats Sandgren Dec 2017

The Role Of Catalytic Residue PKA On The Hydrolysis/Transglycosylation Partition In Family 3 Β-Glucosidases, Inacrist Geronimo, Christina M. Payne, Mats Sandgren

Chemical and Materials Engineering Faculty Publications

β-Glucosidases (βgls) primarily catalyze the hydrolysis of the terminal glycosidic bond at the non-reducing end of β-glucosides, although glycosidic bond synthesis (called transglycosylation) can also occur in the presence of another acceptor. In the final reaction step, the glucose product or another substrate competes with water for transfer to the glycosyl-enzyme intermediate. The factors governing the balance between the two pathways are not fully known; however, the involvement of ionizable residues in binding and catalysis suggests that their pKa may play a role. Through constant pH molecular dynamics simulations of a glycoside hydrolase Family 3 (GH3) βgl, we …


Orbital Misalignment Of The Neptune-Mass Exoplanet Gj 436b With The Spin Of Its Cool Star, Vincent Bourrier, Christophe Lovis, Hervé Beust, David Ehrenreich, Gregory W. Henry, Nicola Astudillo-Defru, Romain Allart, Xavier Bonfils, Damien Ségransan, Xavier Delfosse, Heather M. Cegla, Aurélien Wyttenbach, Kevin Heng, Baptiste Lavie, Francesco Pepe Dec 2017

Orbital Misalignment Of The Neptune-Mass Exoplanet Gj 436b With The Spin Of Its Cool Star, Vincent Bourrier, Christophe Lovis, Hervé Beust, David Ehrenreich, Gregory W. Henry, Nicola Astudillo-Defru, Romain Allart, Xavier Bonfils, Damien Ségransan, Xavier Delfosse, Heather M. Cegla, Aurélien Wyttenbach, Kevin Heng, Baptiste Lavie, Francesco Pepe

Information Systems and Engineering Management Research Publications

The angle between the spin of a star and the orbital planes of its planets traces the history of the planetary system. Exoplanets orbiting close to cool stars are expected to be on circular, aligned orbits because of strong tidal interactions with the stellar convective envelope. Spin–orbit alignment can be measured when the planet transits its star, but such ground-based spectroscopic measurements are challenging for cool, slowly rotating stars. Here we report the three-dimensional characterization of the trajectory of an exoplanet around an M dwarf star, derived by mapping the spectrum of the stellar photosphere along the chord transited by …