Digital Commons Network^™

Red-Winged Blackbird (Agelaius Phoeniceus) Reproduction In North Dakota, Rachel M. Bush, Mark E. Clark, Wendy L. Read, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Structure And Magnetism Of Atomically Thin Fe Layers On Flat And Vicinal Pt Surfaces, D. Repetto, T. Y. Lee, S. Rusponi, Jan Honolka, K. Kuhnke, Violetta Sessi, Ulrich Starke, H. Brune, P. Gambardella, C. Carbone, Axel Enders, K. Kern

Axel Enders Publications

Ultrathin Fe films on Pt substrates have been investigated under ultrahigh vacuum conditions by scanning tunneling microscopy, low energy electron diffraction, magneto-optical Kerr effect, x-ray magnetic circular dichroism measurements, and Kerr microscopy. We present a comparison between Fe films on flat Pt(111) and stepped Pt(997), with particular focus on the magnetic anisotropy in the submonolayer thickness range below 0.2 monolayer coverage, and above the spin reorientation transition at 3 monolayer thickness. The comparison of structure and magnetism suggests that the perpendicular easy axis found for films thinner than three monolayers is due to dominating contributions from both film interfaces to …

The Electronic Structure And Band Hybridization Of Co/Ti Doped Bafe12O19, Natalie Palina, H. Modrow, R. Müller, J. Hormes, Peter A. Dowben, Yaroslav B. Losovyj

Department of Physics and Astronomy: Faculty Publications

We identify contributions to the valence band of the nanosized BaFe_12−2xCo_xTi_xO₁₉ barium ferrite particles, from the cobalt and titanium dopants. Resonant photoemission results show that cobalt and titanium dopants strongly hybridize with the barium ferrite matrix. Fano resonances are identified in the valence band region, at the Ba (5s), Ti (3p) and Co (3p) thresholds, and there are significant contributions to the density of states, residing within 2 eV of the Fermi level, from barium and/or iron.

A Three-Grating Electron Interferometer, G. Gronniger, Brett E. Barwick, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

We report the observation of fringes from a three-grating electron interferometer. Interference fringes have been observed at low energies ranging from 6 to 10 keV. Contrasts of up to 25% are recorded and exceed the maximal contrast of the classical equivalent Moiré deflectometer. This type of interferometer could serve as a separate beam Mach–Zehnder interferometer for low-energy electron interferometry experiments.

Ferromagnetism And Structure Of Epitaxial Cr-Doped Anatase Tio2 Thin Films, T. C. Kaspar, T. Droubay, V. Shutthanandan, S. M. Heald, C. M. Wang, D. E. Mccready, S. Thevuthasan, J. D. Bryan, D. R. Gamelin, A. J. Kellock, M. F. Toney, X. Hong, C. H. Ahn, S. A. Chambers

Xia Hong Publications

The materials and magnetic properties of Cr-doped anatase TiO₂ thin films deposited on LaAlO₃(001) and SrTiO₃(001) substrates by oxygen-plasma-assisted molecular beam epitaxy have been studied in detail to elucidate the origin of ferromagnetic ordering. Cr substitution for Ti in the anatase lattice, with no evidence of Cr interstitials, segregation, or secondary phases, was independently confirmed by transmission electron microscopy with energy dispersive x-ray spectroscopy, extended x-ray absorption fine structure, and Rutherford backscattering spectrometry in the channeling geometry. Epitaxial films deposited at ~0.1 Å/ s were found to have a highly defected crystalline structure, as quantified …

Effect Of Electric Field Doping On The Anisotropic Magnetoresistance In Doped Manganites, X. Hong, J.-B. Yau, J. D. Hoffman, C. H. Ahn

Xia Hong Publications

We have modulated the anisotropic magnetoresistance (AMR) in 3–4 nm manganite films using the ferroelectric field effect—a method that electrostatically varies the carrier density without affecting the lattice distortion. While significant changes have been induced in T_C and p, the AMR ratio remains the same when the magnetic state is not changed. This scaling behavior is in striking contrast to chemical doping results, where similar modulation of the carrier concentration (~0.1/Mn) changes the AMR ratio by ≥30%. The results reveal unambiguously the dominant role of chemical distortion in determining the AMR in manganites.

Regional Patterns In The Isotopic Composition Of Natural And Anthropogenic Nitrate In Groundwater, High Plains, U.S.A., P. B. Mcmahon, J. K. Bohlke

United States Geological Survey: Staff Publications

Mobilization of natural nitrate (NO₃^-) deposits in the subsoil by irrigation water in arid and semiarid regions has the potential to produce large groundwater NO₃^- concentrations. The use of isotopes to distinguish between natural and anthropogenic NO₃^- sources in these settings could be complicated by the wide range in δ¹⁵N values of natural NO₃^-. An ~10 000 year record of paleore-charge from the regionally extensive High Plains aquifer indicates that δ¹⁵N values for NO₃^- derived from natural sources ranged from 1.3 to 12.3‰ and …

Effect Of Method Of Delivering Nicarbazin To Mallards On Plasma 4,4′-Dinitrocarbanilide Levels And Reproduction, C. A. Yoder, J. K. Graham, L. A. Miller, K. S. Bynum, J. J. Johnston, M. J. Goodall

United States Department of Agriculture Wildlife Services: Staff Publications

Nicarbazin (NCZ), a coccidiostat used in the poultry industry, has been developed as a contraceptive for resident Canada geese. We tested the efficacy of NCZ as a contraceptive using mallards (Anas platyrhynchos) as a model for Canada geese. Nicarbazin-treated corn was fed ad libitum for 14 d at 0, 750, 1,000, or 1,500 ppm. Plasma and egg levels of 4,4′-dinitrocarbanilide (DNC), the active anticoccidial component of NCZ, differed among treatment groups in a dose-response relationship, but plasma levels did not differ between sexes. Nicarbazin caused a decrease in egg weight, but there was no effect of NCZ on …

Evaluation Of Nicarbazin As A Potential Waterfowl Contraceptive Using Mallards As A Model, C. A. Yoder, J. K. Graham, L. A. Miller, K. S. Bynum, J. J. Johnston, M. J. Goodall

United States Department of Agriculture Wildlife Services: Staff Publications

Contraception may provide a useful nonlethal management tool to reduce wild bird populations. We tested the efficacy of nicarbazin (NCZ) as a contraceptive for waterfowl and assessed health effects of NCZ, using domestic mallards (Anas platyrhynchos) as a model for Canada geese (Branta canadensis). Mallards were given gelatin capsules containing 0, 8.5, 17.0, or 33.75 mg of NCZ/kg of BW perorally once daily for 14 d. Fecal 4,4′- dinitrocarbanilide (DNC) and fluorescein were evaluated as potential markers of plasma and egg DNC levels. Plasma, egg, and fecal DNC levels differed among treatment groups in a dose …

Molecular Effects Of Nicarbazin On Avian Reproduction, C. A. Yoder, J. K. Graham, L. A. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Nicarbazin (NCZ) is an anticoccidial drug routinely used in the poultry industry that can negatively affect reproduction by reducing egg production, egg weight, and egg hatchability. The molecular mechanisms by which NCZ affects reproduction are unknown. Lipoprotein lipase, vitellogenin, transglutaminase, and calcium are all involved in egg formation and embryogenesis. Therefore, in vitro assays were used to evaluate 4 potential mechanisms of action of NCZ on egg formation and embryogenesis. First, a lipoprotein lipase assay was conducted to determine if NCZ increases lipoprotein lipase activity. Second, vitellogenin phosphorylation was evaluated to determine if NCZ acts as a vitellogenin phosphatase. Third, …

Soybean Cultivars Resulted From More Recombination Events Than Unselected Lines In The Same Population, T. R. Stefaniak, D. L. Hyten Jr., V. R. Pantalone, A. Klarer, T. W. Pfeiffer

Department of Agronomy and Horticulture: Faculty Publications

The selection of superior adapted cultivars has contributed to the doubling of soybean [Glycine max (L.) Merr.] yields in the USA since 1930. Genetic variation was required for this selection to be effective. The objective of this study was to evaluate the importance of homologous chromosome meiotic recombination in the creation of soybean cultivars. A set of 10 adapted high-yielding cultivars selected from the cross ‘Williams’ × ‘Essex’ was com-pared with a set of 156 random recombinant inbred lines (RILs) from the same population. Crossover events were identified using 143 simple sequence repeat (SSR) markers span-ning all 20 soybean …

Circular Ultrasound Compounding By Designed Matrix Weighting, Gregory Bashford, Jonathan Morse

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Spatial compounding is an imaging technique that aims to improve image contrast by combining partially decorrelated images acquired at different angles or positions. In conventional spatial compounding, data sets are combined with equal weighting. Here, we describe an alternative method of reconstruction using algorithms which weight the data based on a “quality” matrix. The quality matrix is derived from beam-forming characteristics. For each data set, the reliability of the data is assumed to vary spatially. By compounding the data based on the quality matrix, a complete image is formed. Here, we describe the construction of a rotational translation stage and …

Modeling Of Transport Phenomena And Melting Kinetics Of Starch In A Co-Rotating Twin-Screw Extruder, Lijun Wang, David D. Jones, Curtis L. Weller, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A mathematical model was developed to simulate fluid flow, heat transfer, and melting kinetics of starch in a co-rotating intermeshing twin-screw extruder (TSE). The partial differential equations governing the transport phenomena of the biomaterial in the extruder were solved by a finite element scheme. For validating the model, the predicted product pressure, bulk temperature at the entrance of the die, and minimum residence time of the biomaterial in the extruder were compared with experimental data. Standard errors of product pressure, bulk temperature at the die entrance, and minimum residence time were about 8.8, 2.8, and 17.3%. Simulations were carried out …

Social Play In Kakapo (Strigops Habroptilus) With Comparisons To Kea (Nestor Notabilis) And Kaka (Nestor Meridionalis), Judy Diamond, Daryl Eason, Clio Reid, Alan B. Bond

Papers in Behavior in Biological Sciences

The play behavior of the critically endangered kakapo (Strigops habroptilus; Aves: Psittaciformes: Psittacidae) is here compared to that of its closest relatives, the kea (Nestor notabilis) and the kaka (Nestor meridionalis). Contrasting kakapos, which are relatively solitary, with the more social Nestor parrots provides an attractive test of the relative contributions of phylogeny and sociality to the evolution of play. Overlapping cluster analysis of play sequences using a hypergeometric similarity metric indicated that kakapo play is generally less complex, lacking the intensity, duration, structure, and reciprocity of play in the Nestor parrots. Kakapos have …

Selective Attention, Priming, And Foraging Behavior, Alan Kamil, Alan B. Bond

Papers in Behavior in Biological Sciences

Animals selectively filter and transform their sensory input, increasing the accuracy with which some stimuli are detected and effectively ignoring others. This filtering process, collectively referred to as “selective attention,” takes place at a variety of different levels in the nervous system. It was described in considerable detail by William James over a century ago (James, 1890/1950) and has been a principal focus of research in cognitive psychology for nearly 50 years (Parasuraman & Davies, 1984; Pashler, 1998; Richards, 1998). Investigations of selective attention have also been central to the study of animal cognition, where the process of attention has …

Spillover Of Agriculturally Subsidized Predators As A Potential Threat To Native Insect Herbivores In Fragmented Landscapes, Tatyana A. Rand, Svata M. Louda

School of Biological Sciences: Faculty Publications

Habitat loss and fragmentation can have strong negative impacts on populations of some native species. Spillover of generalist natural enemies from the surrounding landscape matrix is one mechanism potentially generating such effects, yet this has been rarely studied in insects. We examined the influence of habitat conversion to agriculture on the abundance and potential effects of predatory coccinellid beetles on native insect herbivores within 12 grassland remnants in central Nebraska (U.S.A.). Results of sweep sampling revealed that coccinellids were three to six times more abundant at native grassland sites embedded within cropland- dominated landscapes compared with control sites in grassland-dominated …

Can Environmental Variation Generate Positive Indirect Effects In A Model Of Shared Predation?, Chad Brassil

School of Biological Sciences: Faculty Publications

Classic models of apparent competition predict negative indirect effects between prey with a shared enemy. If predator per capita growth rates are nonlinear, then endogenously generated periodic cycles are predicted to generate less negative or even positive indirect effects between prey. Here I determine how exogenous mechanisms such as environmental variation could modify indirect effects. I find that exogenous variation can have a broader range of effects on indirect interactions than endogenously generated cycles. Indirect effects are altered by environmental variation even in simple models for which the per capita growth rate of the predator species is a linear function …

Anatomy And Physiology Of Giant Neurons In The Antenniform Leg Of The Amblypygid Phrynus Marginemaculatus, A. J. Spence, Eileen Hebets

Eileen Hebets Publications

Amblypygids have modified front legs that are not used for locomotion, but rather to probe the environment in the manner of antennae. These elongate, motile sense organs are referred to as antenniform legs. We have found remarkable replication in structure and function of giant neurons in the antenniform leg of the amblypygid Phrynus marginemaculatus C.L. Koch 1841 when compared with other amblypygids. These neurons have such large diameter axons (several μm) that their action potentials can be recorded outside the cuticle. Their cell bodies are found in the periphery, in the distal-most segments of the antenniform leg, centimeters away from …

Fire Does Not Alter Vegetation In Infertile Prairie, Johannes M.H. Knops

School of Biological Sciences: Faculty Publications

The paradigm in prairie ecology is that fire is one of the key factors deter-mining vegetation composition. fire can impact grassland ecosystems in various ways, including changing plant species composition and inducing nitro-gen loss. I found that 17 years of different burning frequencies in infertile grassland had only a minor impact on the vegetation composition and diversity. The only major impact from increasing the frequency of fires was a decrease of Poa pratensis abundance. However, other plant species did not r-spond to the change in Poa abundance. This result contrasts with previous studies in savannas and more productive grasslands, where …

Kenneth Bloom: Publications List Through January 2006

Kenneth Bloom Publications

Lists 280 publications from arXiv, Physical Review Letters, Physical Review D, Physics Letters B, and IEEE Transactions on Nuclear Science. Includes works in press as of January 2006.

Erratum: Dynamics Of Filament Formation In A Kerr Medium [Phys Rev. A 71, 063811 (2005)], Martin Centurion, Ye Pu, Mankei Tsang, Demetri Psaltis

Martin Centurion Publications

We have found an error in this paper -- [Phys Rev. A 71, 063811 (2005)]. In our calculation of the intensity threshold for breakdown in CS₂ we erroneously used the ionization energy of molecular CS₂ (10.08 eV). The correct value should be 3.3 eV, the band gap energy of liquid CS₂ . Using the band gap energy, nonlinear absorption will be a three-photon process, and the calculated breakdown threshold becomes 8.5 × 10¹¹ W/cm² (as opposed to the value of 2×10¹³ W/cm² reported previously). Multiphoton absorption and plasma defocusing could then become significant …

Dissolution Kinetics Of High Explosives Particles In A Saturated Sandy Soil, Matthew C. Morley, Hiroshi Yamamoto, Gerald E. Speitel, Jr., Jay Clausen

Department of Civil and Environmental Engineering: Faculty Publications

Solid phase high explosive (HE) residues from munitions detonation may be a persistent source of soil and groundwater contamination at military training ranges. Saturated soil column tests were conducted to observe the dissolution behavior of individual components (RDX, HMX, and TNT) from two HE formulations (Comp B and C4). HE particles dissolved readily, with higher velocities yielding higher dissolution rates, higher mass transfer coefficients, and lower effluent concentrations. Effluent concentrations were below solubility limits for all components at superficial velocities of 10–50 cm day^-1. Under continuous flow at 50 cm day^-1, RDX dissolution rates from Comp …

Coupling Between Primary Terrestrial Succession And The Trophic Development Of Lakes At Glacier Bay, Alaska, D. R. Engstrom, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

The natural eutrophication of lakes is still an accepted concept in limnology, arising as it does from the earliest efforts to classify lakes and place them in an evolutionary sequence. Recent studies of newly formed lakes at Glacier Bay, Alaska, only partially support this idea, and suggest more variable trends in lake trophic development which are under local (catchment-level) control. Here we use sediment cores from several lakes in Glacier Bay National Park to examine the relationship between successional changes in catchment vegetation and trends in water-column nitrogen (a limiting nutrient) and lake primary production. Terrestrial succession at Glacier Bay …

Isopiestic Measurement Of The Osmotic Coefficients Of Aqueous {Xh2So4 + (1−X)Fe2(So4)3} Solutions At 298.15 And 323.15 K, Mariano Velazquez-Rivera, Donald Palmer, Richard Kettler

Department of Earth and Atmospheric Sciences: Faculty Publications

This study measures the osmotic coefficients of {xH₂SO₄ +(1−x)Fe₂ (SO₄)₃}(aq) solutions at 298.15 and 323.15 K that have ionic strengths as great as 19.3 mol•kg^-1, using the isopiestic method. Experiments utilized both aqueous NaCl and H₂SO₄ as reference solutions. Equilibrium values of the osmotic coefficient obtained using the two different reference solutions were in satisfactory internal agreement. The solutions follow generally the Zdanovskii empirical linear relationship and yield values of a_w for the Fe₂ (SO₄)₃–H₂O binary system at 298.15 …

Reconstructing Sea-Level Change From The Internal Architecture Of Stromatolite Reefs: An Example From The Mesoproterozoic Sulky Formation, Dismal Lakes Group, Arctic Canada, L C. Kah, Julie K. Bartley, Tracy D. Frank, Timothy W. Lyons

Department of Earth and Atmospheric Sciences: Faculty Publications

The Mesoproterozoic Dismal Lakes Group, arctic Canada, contains a relatively thin, yet regionally extensive stromatolitic reef complex that developed subtidally during a major transgression, shoaled to sea level, and was overlain by intertidal to supratidal carbonate and evaporite strata. The September Lake reef complex exhibits a complex internal architecture that records the interaction between stromatolite growth and changes in accommodation space derived from both higher order (4th- or 5th-order, parasequence-scale) changes in sea level and the variable bathymetry of the sea floor. Reef growth, which was initiated during three sea-level cycles, records progressive marine transgression over depositional lows that were …

Radio Frequency Identification Technology: Applications, Technical Challenges And Strategies, Suhong Li, John K. Visich, Basheer M. Khumawala, Chen Zhang

Management Department Faculty Journal Articles

Purpose - The purpose of this paper is to discuss the technology behind RFID systems, identify the applications of RFID in various industries, and discuss the technical challenges of RFID implementation and the corresponding strategies to overcome those challenges.

Design/methodology/approach - Comprehensive literature review and integration of the findings from literature. Findings - Technical challenges of RFID implementation include tag cost, standards, tag and reader selection, data management, systems integration and security. The corresponding solution is suggested for each challenge.

Research limitations/implications - A survey type research is needed to validate the results.

Practical implications - This research offers useful …

Simulation Model And Analysis Of A Data Warehouse, Vikas Agrawal, Udayan Nandkeolyar, P.S. Sundararaghavan, Mesbah U. Ahmed

Journal of International Technology and Information Management

Data warehouses are large complex systems with many interacting nonlinear components. It is an amalgamation of many different systems and integration of such diverse elements is its primary concern. It is often difficult for a data warehouse manager to predict the performance of the system especially when demand pattern for the required data keeps changing. We have developed a simulation model using ARENA simulation package that will simulate the behavior and performance of a data warehouse system environment based on its overall design. Given such a model, a data warehouse manager can walk through various what-if scenarios and can pinpoint …

Grey Situation Decision-Making Algorithm To Optimize Silicon Wafer Slicing, Che-Wei Chang, William Yu Chung Wang

Journal of International Technology and Information Management

The slicing of Silicon wafer is a complex manufacturing process in producing the raw materials for electronic chips and requires the efforts to effectively monitor the stability in production line and ensure the quality for the products composed of different shapes and materials. Human decision failure and other analytical errors are the most common source of management problems in such manufacturing stage. This paper presents a case regarding the silicon wafer manufacturing to examine the response to quality errors. The study has adopted the approach of grey situation decision-making algorithm for problem detection that suggests a technique to attain the …

Interrelationships Among Language Skills, Externalizing Behavior, And Academic Fluency And Their Impact On The Academic Skills Of Students With Ed, J. Ron Nelson, Gregory J. Benner, Stern Neill, Scott A. Stage

Department of Special Education and Communication Disorders: Faculty Publications

There is growing interest in understanding the factors that influence the academic achievement of students with emotional disturbance (ED). Structural equation modeling was used to test the interrelationships among language skills, externalizing behavior, and academic fluency and their impact on the academic skills of students with ED. Results showed that language skills exerted a significant proximal effect and distal effect on academic skills. The effect of language skills was mediated through academic fluency (path coefficient = .389) but also had a proximal effect on academic skills (path coefficient = .359). However, externalizing behavior failed to have a statistically significant effect …

Negative Impact Of Noise On The Principal Component Analysis Of Nmr Data, Steven M. Halouska, Robert Powers

Department of Chemistry: Faculty Publications

Principal component analysis (PCA) is routinely applied to the study of NMR based metabolomic data. PCA is used to simplify the examination of complex metabolite mixtures obtained from biological samples that may be composed of hundreds or thousands of chemical components. PCA is primarily used to identify relative changes in the concentration of metabolites to identify trends or characteristics within the NMR data that permits discrimination between various samples that differ in their source or treatment. A common concern with PCA of NMR data is the potential over emphasis of small changes in high concentration metabolites that would over-shadow signifi …