77 Works

On the accuracy of explicitly correlated coupled-cluster interaction energies - have orbital results been beaten yet?

Konrad Patkowski
The basis set convergence of weak interaction energies for dimers of noble gases helium through krypton is studied for six variants of the explicitly correlated, frozen geminal coupled-cluster singles, doubles, and noniterative triples [CCSD(T)-F12] approach: the CCSD(T)-F12a, CCSD(T)- F12b, and CCSD(T)(F12*) methods with scaled and unscaled triples. These dimers were chosen because CCSD(T) complete-basis-set (CBS) limit benchmarks are available for them to a particularly high precision. The dependence of interaction energies on the auxiliary basis...

Subunit D of RNA Polymerase from Methanosarcina acetivorans Contains Two Oxygen-labile [4Fe-4S] Clusters IMPLICATIONS FOR OXIDANT-DEPENDENT REGULATION OF TRANSCRIPTION

Faith H. Lessner, Matthew E. Jennings, Akira Hirata, Eduardus C. Duin & Daniel J. Lessner
Subunit D of multisubunit RNA polymerase from many species of archaea is predicted to bind one to two iron-sulfur (Fe-S) clusters, the function of which is unknown. A survey of encoded subunit D in the genomes of sequenced archaea revealed six distinct groups based on the number of complete or partial [4Fe-4S] cluster motifs within domain 3. Only subunit D from strictly anaerobic archaea, including all members of the Methanosarcinales, are predicted to bind two...

Valence and diffuse-bound anions of noble-gas complexes with uracil

Livia Streit, O. Dolgounitcheva, V. G. Zakrzewski, J. V. Ortiz & Joseph Vincent Ortiz
Valence-bound (VB) and diffuse-bound (DB) anions of noble-gas (Ar, Kr, and Xe) complexes with uracil have been studied with ab initio methods. MP2 optimizations revealed minima corresponding to anions of both kinds in each case. Coupled-cluster singles and doubles with perturbative triples, CCSD(T), and electron propagator single-point calculations were performed in order to assess vertical and adiabatic electron detachment energies of these complexes. Ab initio electron propagator calculations employed the outer valence Green’s function and...

Interpretation of the photoelectron spectra of superalkali species: Li3O and Li3O-

S. Zein & J. V. Ortiz
The present paper deals with the interpretation of the photoelectron spectrum of the Li3O-. After several failed attempts to attribute all of the observed peaks in the experimental spectrum to anionic species, neutral species were considered assuming a sequential two-photon absorption mechanism. We find that only two of the six observed peaks can be attributed to photodetachments and that all other observed features can be assigned to ionizations from the ground and excited states of...

Performance of cotton varieties in Alabama, 2020

Henry G. Jordan
Caption title. "January 11, 2021."

OH3- and O2H5- double Rydberg anions: Predictions and comparisons with NH4- and N2H7-

Junia Melin & J.V. Ortiz
A low barrier in the reaction pathway between the double Rydberg isomer of OH3 − and a hydride-water complex indicates that the former species is more difficult to isolate and characterize through anion photoelectron spectroscopy than the well known double Rydberg anion DRA, tetrahedral NH4 − . Electron propagator calculations of vertical electron detachment energies VEDEs and isosurface plots of the electron localization function disclose that the transition state’s electronic structure more closely resembles that...

Wild Pigs: inciting factor in southern pine decline?

Lori G. Eckhardt, Roger D. Menard & Stephen S. Ditchkoff
During an investigation into southern pine decline at Fort Benning Georgia, the possibility of wild pigs (Sus scrofa) as an inciting factor became evident. Their rooting activity caused significant root damage on sites showing symptoms of pine decline. It was thought that perhaps the pigs may be moving around pathogenic fungi during their rooting activity in Pinus taeda (loblolly pine) stands. In 2008 and 2010, fungal isolates were obtained from the snouts of wild pigs...

Alterations to sediment nutrient deposition and transport along a six reservoir sequence

Benjamin Webster, Matthew Waters & Stephen Golladay
Reservoir presence and construction has become commonplace along rivers due to the multitude of ecosystem services they provide. Many services are well recognized, including the effectiveness of sequestering both sediments and sediment-bound nutrients such as silts and phosphorus (P). Reservoirs are also capable of transforming or sequestering significant quantities of nutrients with more complex biogeochemical pathways, like nitrogen (N). Reservoir assessments, independent of inflow-outflow models, have primarily focused on a small number of systems creating...

Translocation to a fragmented landscape: survival, movement, and site fidelity of Northern Bobwhites

Theron M. Terhune, D. Clay Sisson, William E. Palmer, , H. Lee Stribling & John P. Carroll
Habitat fragmentation, degradation, and loss have taxed early-successional species including the Northern Bobwhite (Colinus virginianus) and numerous grassland obligate birds. Translocation is often applied to counteract the consequences of habitat fragmentation through the creation, reestablishment, or augmentation of wild populations for the purposes of conservation, biodiversity maintenance. However, the implementation of these techniques is often conducted without valid experimental designs and therefore lacks robust, empirical data needed to evaluate and advance the knowledge and application...

Support Scholars Who Share: Combating the Mismatch between Openness Policies and Professional Rewards

Ali Krzton & Alicia Krzton
Are institutional policies designed to advance open scholarship capable of accomplishing that end? What other consequences might they have for the practice of research? These mandates undoubtedly increase the number of publicly-available articles and datasets in the short-term, but there is also an expectation that as researchers become accustomed to the new requirements, the culture within their disciplines will shift to support open research, for instance through the founding of new open-access journals or platforms....

Why does ethical leadership matter? Exploration and future direction for sales research

Emory Serviss & Jennifer Henderson
The purpose of this study is to gain a better understanding of the relationship between ethical leadership and an employee’s work-related attitudes about, and behaviors for, their company. Using social learning theory, the authors examine how a manager’s ethical leadership influences the relationship between an employee’s job satisfaction and organizational commitment. This research uses structural equation modeling (SEM) to investigate the direct and moderated relationships among these variables using data from 250-employees working in United...

Effects of human activity on the habitat utilization of Himalayan marmot (Marmota himalayana) in Zoige wetland

Shuailing Zhou, Ali Krzton, Shuai Gao, Cheng Guo & Zuofu Xiang
Human activity is increasingly and persistently disturbing nature and wild animals. Affected wildlife adopts multiple strategies to deal with different human influences. To explore the effect of human activity on habitat utilization of Himalayan marmot (Marmota himalayana), habitat utilization patterns of three neighboring marmot populations in habitats affected differently by human activities were recorded and compared. We found that (a) distance between reproductive burrows (a represent of reproductive pairs) becomes shorter under the influence of...

Experimental and numerical investigation of saltwater intrusion dynamics in flux-controlled groundwater systems

Sun Woo Chang & T. Prabhakar Clement
Sea level rise and reduction of groundwater fluxes due to changes in rainfall patterns are the two major climate change–induced hydrological variables that can severely affect saltwater intrusion in coastal aquifers. In this study we use a combination of laboratory experiments and numerical simulations to study the impacts of changes in one of these climate change–induced hydrological variables, groundwater flux, on saltwater intrusion process. We have completed experiments in a laboratory-scale model to study the...

Performance of soybean cultivars in Alabama, 2014

Kathryn M. Glass, , & Jon H. Brasher
"December 2014."

Electron propagator calculations on C-60 and C-70 photoelectron spectra

V. G. Zakrzewski, O. Dolgounitcheva & J.V. Ortiz
Vertical ionization energies of C60 and C70 fullerenes are calculated with semidirect implementations of electron propagator methods and a triple- plus polarization basis set. These predictions are in close agreement with photoelectron spectra for final states in which the Koopmans description is qualitatively valid. Many correlation states, where the latter description fails, are predicted by methods with nondiagonal self-energies.

Surface Green’s function calculations: A nonrecursive scheme with an infinite number of principal layers

Aleksey Kletsov, Yuri Dahnovsky & J.V. Ortiz
A novel computational method for a surface Green’s function matrix is introduced for the calculation of electrical current in molecular wires. The proposed nonrecursive approach includes an infinite number of principal layers and yields the second-order matrix equation for the transformed Green’s function matrix. The solution is found by the direct diagonalization of the auxiliary matrix without any iteration process. As soon as complex roots of the auxiliary matrix Gˆ S are calculated, the gaps...

Partial photoionization cross sections of and Rydberg radicals

A.M. Velasco, C. Lavin, I. Martin, J. Melin & J.V. Ortiz
ammonium and oxonium Rydberg radicals from the outermost, occupied orbitals of their respective ground states are reported. These properties are known to be relevant in photoelectron dynamics studies. For the present calculations, the molecular-adapted quantum defect orbital method has been employed. A Cooper minimum has been found in the 3sa1-kpt2 Rydberg channel of NH4 beyond the ionization threshold, which provides the main contribution to the photoionization of this radical. However, no net minimum is found...

Second-order, two-electron Dyson propagator theory: Comparisons for vertical double ionization potentials

T. Ida & J.V. Ortiz
The second-order, two-electron Dyson propagator is derived using superoperator theory with a spin-adapted formulation. To include certain ladder diagrams to all orders, the shifted-denominator SD2 approximation is made. Formal and computational comparisons with other approximations illustrate the advantages of the SD2 procedure. Vertical double ionization potentials DIPs for a set of closed-shell molecules are evaluated with the second-order propagator and the SD2 method. The results of the SD2 approximation are in good agreement with experiment....

Preliminary performance of soybeans in Alabama, 2020

Henry G. Jordan
Caption title. "January 13, 2021."

Fishes of the Streams of Acadia National Park, Maine

Justin C. Havird, Jennifer K. Parker & Bruce Connery
Acadia National Park (ANP) is a non-continuous conglomerate of park lands interspersed with private lands, which is located mainly on Mount Desert Island, ME. Surveys of fishes in ANP have largely ignored or under-sampled most of the streams on the island. Reported here are the results of a 2009 survey that sampled freshwater fishes in 43 streams flowing through Park boundaries. Overall, 19 species were collected, and many were recorded from specific streams for the...

Data for: Evaluation of dissolved carbon dioxide to stimulate emergence of red swamp crayfish Procambarus clarkii (Decapoda: Cambaridae) from invaded ponds

Hisham Abdelrahman, Rebecca Gibson, Kaelyn Fogelman, Aaron Cupp, Ann Allert & James Stoeckel
Invasive crayfish have adverse effects on habitats and native species. Control of invasive crayfish populations is a major challenge facing natural resource managers. This study evaluated the effectiveness and optimal conditions for the control agent carbon dioxide (CO2) which can be diffused into water to facilitate capture of red swamp crayfish (Procambarus clarkii; RSC). The efficacy of CO2 shows promise in its use for a variety of invasive aquatic species. Here, we evaluate CO2’s ability...

Images of natural comb

Michael L Smith & Patricia Hartman

Heat-induced maternal effects shapes avian eggshell traits and embryo response to high temperatures

Alexander Hoffman, Leslie Dees & Haruka Wada
Populations without a sufficient rate of genetic adaptation may risk extinction in the face of rapid environmental change, however, phenotypic plasticity can facilitate their persistence. For example, mothers can prepare offspring for the thermal environment young will experience through transgenerational plasticity. In oviparous species, whether mothers can prepare offspring to cope with thermal stress experienced as embryos is largely unknown. We demonstrate that when zebra finch mothers are exposed to a heat stress, their offspring...

Alabama cotton variety tests 1974

Cover title. "February 1975."

1977 Alabama grain sorghum performance tests

& Cliff G. Currier
Cover title. "February 1978."

Registration Year

  • 2021
  • 2020

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