Physical Sciences and Mathematics Commons^™

Net Geochemical Release Of Base Cations From 25 Forested Watersheds In The Catskill Region Of New York, Sara C. Nieman, Chris E. Johnson

Civil and Environmental Engineering

Chemical weathering of minerals is the principal mechanism by which base cations (Ca²⁺, Mg²⁺, K⁺, and Na⁺) are released and acidity is neutralized in soils, bedrock and drainage waters. Quantifying the release of base cations from watershed soils is therefore crucial for the calculation of “critical loads” of atmospheric acidity to forest ecosystems. We used a mass-balance approach to estimate the rate of release of base cations in 25 headwater catchments in the Catskill region of New York, an area historically subject to high inputs of acid deposition. In 2010-2013, total net …

Chemical Shift Assignments Of The N-Terminal Domain Of Psd95 (Psd95-Nt), Yonghong Zhang, Johannes W. Hell, James B. Ames

Chemistry Faculty Publications and Presentations

Postsynaptic density protein-95 (PSD95) contributes to the postsynaptic architecture of neuronal synapses and plays an important role in controlling synaptic plasticity. The N-terminal domain of PSD95 (residues 1–71, called PSD95-NT) interacts with target proteins (calmodulin, α-actinin-1 and CDKL5), which regulate the Ca2+-dependent degradation of glutamate receptors. We report complete backbone NMR chemical shift assignments of PSD95-NT (BMRB No. 50752).

Evidence For Accelerated Weathering And Sulfate Export In High Alpine Environments, John T. Crawford, Eve-Lyn S. Hinckley, M. Iggy Litaor, Janice Brahney, Jason C. Neff

Watershed Sciences Faculty Publications

High elevation alpine ecosystems—the 'water towers of the world'—provide water for human populations around the globe. Active geomorphic features such as glaciers and permafrost leave alpine ecosystems susceptible to changes in climate which could also lead to changing biogeochemistry and water quality. Here, we synthesize recent changes in high-elevation stream chemistry from multiple sites that demonstrate a consistent and widespread pattern of increasing sulfate and base cation concentrations or fluxes. This trend has occurred over the past 30 years and is consistent across multiple sites in the Rocky Mountains of the United States, western Canada, the European Alps, the Icelandic …

Sulfonamide Synthesis Via Calcium Triflimide Activation Of Sulfonyl Fluorides, Nicholas Ball, Paramita Mukherjee, Cristian P. Woroch, Leah Cleary, Mark Rusznak, Ryan W. Franzese, Matthew R. Reese, Joseph W. Tucker, John M. Humphrey, Sarah M. Etuk, Sabrina C. Kwan, Christopher W. Am Ende

Pomona Faculty Publications and Research

A method using calcium triflimide [Ca(NTf₂)₂] as a Lewis acid to activate sulfonyl fluorides toward nucleophilic addition with amines is described. The reaction converts a wide array of sterically and electronically diverse sulfonyl fluorides and amines into the corresponding sulfonamides in good yield.

Calcium-Mediated Control Of S100 Proteins: Allosteric Communication Via An Agitator/Signal Blocking Mechanism., Yiming Xiao, Gary S Shaw, Lars Konermann

Chemistry Publications

Allosteric proteins possess dynamically coupled residues for the propagation of input signals to distant target binding sites. The input signals usually correspond to "effector is present" or "effector is not present". Many aspects of allosteric regulation remain incompletely understood. This work focused on S100A11, a dimeric EF-hand protein with two hydrophobic target binding sites. An annexin peptide (Ax) served as the target. Target binding is allosterically controlled by Ca²⁺ over a distance of ∼26 Å. Ca²⁺ promotes formation of a [Ca₄ S100 Ax₂] complex, where the Ax peptides are accommodated between helices III/IV and III'/IV'. …

A Natural, Calcium-Rich Marine Multi-Material Complex Preserves Bone Structure, Composition And Strength In An Ovariectomized Rat Model Of Osteoporosis, Orlaith Brennan, Joseph Sweeney, Brian O'Meara, Amro Widaa, Franck Bonnier, Hugh Byrne, Denis O'Gorman, Fergal O'Brien

Articles

Calcium supplements are used as an aid in the prevention of osteopenia and osteoporosis and also for the treatment of patients when used along with medication. Many of these supplements are calcium carbonate based. This study compared a calcium-rich, marine multi-mineral complex (Aquamin) to calcium carbonate in an ovariectomised rat model of osteoporosis in order to assess Aquamin’s efficacy in preventing the onset of bone loss. Animals were randomly assigned to either non-ovariectomy control (Control), ovariectomy (OVX) plus calcium carbonate, ovariectomy plus Aquamin or ovariectomy plus Aquamin delay where Aquamin treatment started 8 weeks post OVX. At the end of …

Feasibility Of Laser-Induced Breakdown Spectroscopy (Libs) As An At-Line Validation Tool For Calcium Determination In Infant Formula, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Yash Dixit, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Patrick J. Cullen, Carl Sullivan

Articles

In this study, a 150 mJ laser-induced breakdown spectroscopy (LIBS) system was assessed to determine calcium content in infant formula (IF) samples. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers advantages over conventional methods such as real-time analyses, little to no sample preparation and ease of use. The aim of this work was to evaluate the feasibility of LIBS as an at-line tool for IF manufacturing. To this end, IF mixtures with varying content of calcium were prepared over a range (approx. 1.5–7 mg/g of calcium) selected to be in conformity with the guidelines provided by …

Longevity Of Mineral Supplements Within The Soil And Associated Use By White-Tailed Deer, Brian C. Peterson, Keith D. Koupal, Andrew K. Schissel, Cody M. Siegel

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Humans have baited wildlife such as white-tailed deer (Odocoileus virginianus) for generations with the primary purpose of increasing hunting harvest success. Baiting regulation changes are often considered by state management agencies as they pertain to hunting opportunity, fair chase, and disease risk. Cervids require a variety of minerals to supplement biological processes, especially sodium (Na), calcium (Ca), and phosphorus (P). We developed artificial mineral supplement sites set in front of trail cameras to monitor deer use. Pooled soil samples were collected at mineral sites and compared to the surrounding area to determine the longevity of elevated minerals levels …

The 2d Distribution Of Iron-Rich Ejecta In The Remnant Of Sn 1885 In M31, Robert A. Fesen, Peter A. Höflich, Andrew J. S. Hamilton

Dartmouth Scholarship

We present Hubble Space Telescope (HST) ultraviolet Fe i and Fe ii images of the remnant of Supernova 1885 (S And) which is observed in absorption against the bulge of the Andromeda galaxy, M31. We compare these Fe i and Fe ii absorption line images to previous HST absorption images of S And, of which the highest quality and theoretically cleanest is Ca ii H and K. Because the remnant is still in free expansion, these images provide a 2D look at the distribution of iron synthesized in this probable Type Ia explosion, thus providing insights and constraints …

Direct Determination Of Multiple Ligand Interactions With The Extracellular Domain Of The Calcium Sensing Receptor, Chen Zhang, You Zhuo, Heather A. Moniz, Shuo Wang, Kelley W. Moremen, James H. Prestegard, Edward M. Brown, Jenny J. Yang

Chemistry Faculty Publications

Numerous in vivo functional studies have indicated that the dimeric extracellular domain (ECD) of the CaSR plays a crucial role in regulating Ca2+ homeostasis by sensing Ca2+ and L-Phe. However, direct interaction of Ca2+ and Phe with the receptor’s ECD and the resultant impact on its structure and associated conformational changes have been hampered by the large size of the ECD, its high degree of glycosylation, and the lack of biophysical methods to monitor weak interactions in solution. In the present study, we purified the glycosylated extracellular domain of CaSR (ECD) (residues 20~612), containing either complex or high mannose N-glycan …

The Association Of Calcium Intake And Other Risk Factors With Cardiovascular Disease Among Obese Adults In Usa, Yang Chen, Sheryl Strasser, Katie Callahan, David Blackley, Yan Cao, Liang Wang, Shimin Zheng

ETSU Faculty Works

In this study, we used a cross-sectional study design to examine the relationship between the calcium intake and risk factors for CVD among obese adults by using continuous waves of National Health and Nutrition Examination Survey (NHANES) data 1999-2010. The association between calcium intake and risk factors of CVD (hypertension, total cholesterol, HDL, glycohemoglobin), CRP, albuminuria) is assessed among obese adults in USA. The incidence of Cardiovascular Disease (CVD) is high among obese people. The potential effects of inadequate calcium intake on CVD are receiving increased epidemiologic attention. Understanding the association between risk factors for CVD and calcium intake among …

Heart Failure And Design Of Potentially Therapeutic Mutants Relieving Serca Inhibition: Expression And Analysis Of Phospholamban Mutants, Kristina R. Poss

Antonian Scholars Honors Program

The CDC identifies heart disease as the leading cause of death in the U.S., and current treatments have variable success. Gene therapy is being investigated as an additional treatment option for heart disease. Various targets impacting calcium ion cycling and by consequence, cardiac contractility, are being studied as options for gene therapy. One molecular target in particular is the protein phospholamban (PLN), which is a small, hydrophobic protein located in the sarcoplasmic reticulum membrane of cardiac muscle, that has been linked to heart failure. Here, four PLN mutants were rationally designed, aiming for optimizing therapeutic potential. These mutants were analyzed …

Increasing Ca2+ Deposition In The Western Us: The Role Of Mineral Aerosols, Janice Brahney, Ashley P. Ballantyne, C. Sievers, Jason C. Neff

Watershed Sciences Faculty Publications

Considerable research has focused on the role of industrial emissions in controlling the acidity of precipitation; however, much less research has focused on the role of mineral aerosols emitted from soils. According to data published by the National Atmospheric Deposition Network (NADP), over the past 17 years Ca2+ deposition has increased over large regions of the US. A trend analysis to determine regions of significant change in Ca2+ deposition revealed statistically significant increases in three broad regions within the western half of the country: the inter-mountain west, the midwest, and the northwest. We evaluated potential changes in sources of calcium …

Slides: Colorado Law: Protecting Water Quantity And Quality, Alan E. Curtis

Monitoring and Protecting Groundwater During Oil and Gas Development (November 26)

Presenter: Alan E. Curtis, White & Jankowski, LLP

23 slides

Disorder Promotes Ferromagnetism: Rounding Of The Quantum Phase Transition In Sr₁₋ₓcaₓruo₃, Laszlo Demko, Sandor Bordacs, Thomas Vojta, David Nozadze, Fawaz Hrahsheh, Christopher Svoboda, Balazs Dora, Hiroyuki Yamada, Masashi Kawasaki, Yoshinori Tokura, Istvan Kezsmarki

Physics Faculty Research & Creative Works

The subtle interplay of randomness and quantum fluctuations at low temperatures gives rise to a plethora of unconventional phenomena in systems ranging from quantum magnets and correlated electron materials to ultracold atomic gases. Particularly strong disorder effects have been predicted to occur at zero-temperature quantum phase transitions. Here, we demonstrate that the composition-driven ferromagnetic-to-paramagnetic quantum phase transition in Sr_1-xCa_xRuO₃ is completely destroyed by the disorder introduced via the different ionic radii of the randomly distributed Sr and Ca ions. Using a magneto-optical technique, we map the magnetic phase diagram in the composition-temperature space. We find …

Structural Basis For Ca 2+-Induced Activation And Dimerization Of Estrogen Receptor Alpha By Calmodulin, Yonghong Zhang, Zhigang Li, David B. Sacks, James B. Ames

Chemistry Faculty Publications and Presentations

The estrogen receptor α (ER-α) regulates expression of target genes implicated in development, metabolism, and breast cancer. Calcium-dependent regulation of ER-α is critical for activating gene expression and is controlled by calmodulin (CaM). Here, we present the NMR structures for the two lobes of CaM each bound to a localized region of ER-α (residues 287–305). A model of the complete CaM·ER-α complex was constructed by combining these two structures with additional data. The two lobes of CaM both compete for binding at the same site on ER-α (residues 292, 296, 299, 302, and 303), which explains why full-length CaM binds …

Ionic Selectivity In L-Type Calcium Channels By Electrostatics And Hard-Core Repulsion, Dezso Boda, Douglas Henderson, Monika Valisko, Bob Eisenberg, Dirk Gillespie

Faculty Publications

A physical model of selective "ion binding" in the L-type calcium channel is constructed, and consequences of the model are compared with experimental data. This reduced model treats only ions and the carboxylate oxygens of the EEEE locus explicitly and restricts interactions to hard-core repulsion and ion–ion and ion–dielectric electrostatic forces. The structural atoms provide a flexible environment for passing cations, thus resulting in a self-organized induced-fit model of the selectivity filter. Experimental conditions involving binary mixtures of alkali and/or alkaline earth metal ions are computed using equilibrium Monte Carlo simulations in the grand canonical ensemble. The model pore rejects …

Comment On "Generation Of Cold Low Divergent Atomic Beam Of Indium By Laser Ablation", A. Denning, A. Booth, S. Lee, M. Amonson, Scott D. Bergeson

Faculty Publications

We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, this method does not generate a subthermal atomic beam.

The Effect Of Protein Dielectric Coefficient On The Ionic Selectivity Of A Calcium Channel, Douglas Henderson, Dezso Boda, Monika Valisko, Bob Eisenberg, Wolfgang Nonner, Dirk Gillespie

Faculty Publications

Calcium-selective ion channels are known to have carboxylate-rich selectivity filters, a common motif that is primarily responsible for their high Ca2+ affinity. Different Ca2+ affinities ranging from micromolar (the L-type Ca channel) to millimolar (the ryanodine receptor channel) are closely related to the different physiological functions of these channels. To understand the physical mechanism for this range of affinities given similar amino acids in their selectivity filters, we use grand canonical Monte Carlo simulations to assess the binding of monovalent and divalent ions in the selectivity filter of a model Ca channel. We use a reduced model where the electrolyte …

Fluorescence Measurements Of Expanding Strongly Coupled Neutral Plasmas, E. A. Cummings, J. E. Daily, Dallin S. Durfee, Scott D. Bergeson

Faculty Publications

We report new detailed density profile measurements in expanding strongly coupled neutral calcium plasmas. Using laser-induced fluorescence techniques, we determine plasma densities in the range of 10^5 to 10^9 cm^-3 with a time resolution limit as small as 7 ns. Strong coupling in the plasma ions is inferred directly from the fluorescence signals. Evidence for strong coupling at late times is presented, confirming a recent theoretical result.

Two-Photon Photoionization Of The Ca 4s3d^1d2 Level In An Optical Dipole Trap, E. A. Cummings, J. E. Daily, Dallin S. Durfee, Scott D. Bergeson, R. Gommers

Faculty Publications

We report an optical dipole trap for calcium. The trap is created by focusing a 488-nm argon-ion laser beam into a calcium magneto-optical trap. The argon-ion laser photoionizes atoms in the trap because of a near-resonance with the 4s4f 1^F3 level. By measuring the dipole-trap decay rate as a function of argon-ion laser intensity, we determine the 1^F3 photoionization cross section at our wavelength to be approximately 230 Mb.

Evidence For Microbial Enhanced Electrical Conductivity In Hydrocarbon-Contaminated Sediments, Estella A. Atekwana, Eliot A. Atekwana, D. Dale Werkema, Jonathan P. Allen, Laura A. Smart, Joseph W. Duris, Daniel P. Cassidy, William A. Sauck, Silvia Rossbach

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Bulk electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale laboratory experiment consisting of biotic contaminated and uncontaminated columns. Population numbers of oil degrading microorganisms increased with a clear pattern of depth zonation within the contaminated column not observed in the uncontaminated column. Microbial community structure determined from ribosomal DNA intergenic spacer analysis showed a highly specialized microbial community in the contaminated column. The contaminated column showed temporal increases in bulk conductivity, dissolved inorganic carbon, and calcium, suggesting that the high bulk conductivity is due to enhanced mineral weathering from microbial activity. The greatest change …

Analysis Of The Mechanism By Which Calcium Negatively Regulates The Tyrosine Phosphorylation Cascade Associated With Sperm Capacitation, Mark Baker, Louise Hethrington, Heath W. Ecroyd, Shaun D. Roman, Robert J. Aitken

Faculty of Science - Papers (Archive)

The capacitation of mammalian spermatozoa involves the activation of a cAMP-mediated signal transduction pathway that drives tyrosine phosphorylation via mechanisms that are unique to this cell type. Controversy surrounds the impact of extracellular calcium on this process, with positive and negative effects being recorded in independent publications. We clearly demonstrate that the presence of calcium in the external medium decreases tyrosine phosphorylation in both human and mouse spermatozoa. Under these conditions, a rise in intracellular pH was recorded, however, this event was not responsible for the observed changes in phosphotyrosine expression. Rather, the impact of calcium on tyrosine phosphorylation in …

The Development Of Signal Transduction Pathways During Epididymal Maturation Is Calcium Dependent, Heath W. Ecroyd, Kelly Asquith, Russell C. Jones, Robert J. Aitken

Faculty of Science - Papers (Archive)

Capacitation has been correlated with the activation of a cAMP-PKA-dependent signaling pathway leading to protein tyrosine phosphorylation. The ability to exhibit this response to cAMP matures during epididymal maturation in concert with the ability of the sperrnatozoa to capacitate. In this study, we have addressed the mechanisms by which spermatozoa gain the potential to activate this signaling pathway during epididymal maturation. In a modified Tyrode's medium containing 1.7 mM calcium, caput spermatozoa had significantly higher [Ca2+](i) than caudal cells and could not tyrosine phosphorylate in response to cAMP. However, in calcium-depleted medium both caput and caudal cells could exhibit a …

Electric Field Controlled, Pulsed Autoionization In Two Electron Wave Packets, J. Greg Story, Heider N. Ereifej

Physics Faculty Research & Creative Works

In this paper, control of the evolution of a two electron wave packet through the application of a static electric field is demonstrated. Specifically, application of a small electric field is used to produce pulsed autoionization events, the timing of which can be controlled on a picosecond time scale. The technique is demonstrated by exciting calcium atoms using a short-pulsed laser to the 4p_3/219d doubly excited state, which is energy degenerate with the 4p_1/2nk stark states. Evolution of the resultant wave packet is monitored through the application of a second short laser pulse, which stimulates the …

Direct Measurement Of Oscillations Between Degenerate Two-Electron Bound-State Configurations In A Rapidly Autoionizing System, Heider N. Ereifej, J. Greg Story

Physics Faculty Research & Creative Works

In this paper we report a direct observation of the oscillation between bound-state configurations in a rapidly autoionizing system. Calcium atoms were excited to a pure 4p_3/2nd two-electron configuration using a 500-fsec laser pulse. The initial 4p_3/2nd doubly excited state is energy degenerate with the 4p_1/2n'd states and several continuum channels. Because of the short-pulse excitation, the initial state of the atom is not an energy eigenstate, but a nonstationary wave packet. As a result, oscillations between the two bound configurations were produced. These oscillations were measured by scanning the timing of a second …

Determination Of Calcium, Magnesium And Strontium In Soils By Flow Injection Flame Atomic Absorption Spectrometry, Z Arslan, Jf Tyson

Chemistry Department Faculty Publication Series

No abstract provided.

Superfluorescence From Optically Trapped Calcium Atoms, Xianming Han

Scholarship and Professional Work - LAS

We have studied superfluorescence (SF) under highly unfavorable conditions of rapid collisional and radiative distribution in a Doppler-broadened medium. Nanosecond SF pulses at 5.5 μm were generated on the Ca 4s4p1P1–3d4s1D2 transition from a column of calcium vapor buffered with Ar by optically pumping the 4s21S0–4s4p1P1 transition. The Rabi frequency associated with the intense pump pulse prevents the occurrence of SF while the pump laser is on. As a result, the predicted scaling laws that describe the properties of SF in a transversely excited system, such as peak heights, pulse widths, and delay times, are shown to apply in our …

Observations Of The Ca Ii Infrared Triplet In Chromospherically Active Single And Binary Stars, Robert C. Dempsey, Bernard W. Bopp, Gregory W. Henry, Douglas S. Hall

Information Systems and Engineering Management Research Publications

Spectroscopic observations of the Ca II infrared triplet (8498, 8542, 8662 A) have been obtained for 45 stars which are known or suspected to be chromospherically active. The sample includes both single and binary stars of spectral types from F2 to M5 spanning luminosity classes III, IV, and V. Several different types of activity diagnostics were measured, and their relative merits are discussed. Dependence of chromospheric emission upon rotation period, luminosity, temperature, and duplicity are analyzed. Synchronous binaries show a slight trend of increased emission with decreasing period while the asynchronous binaries show abnormally high activity levels for their rotation …

Flow-Injection Atomic Spectrometry: A New Analytical Technique, Julian Tyson, S. R. Bysouth, Ea Grzeszczyk, Ebenezer Debrah

Chemistry Department Faculty Publication Series

No abstract provided.