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2000

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A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech Jan 2000

A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

This report documents a pack of 22-23 Wolves (Canis lupus) in central Minnesota. This is larger than the largest pack previously observed on the mainland in the midwestern U.s. during 650 wolf pack-years. Because this record-large pack preyed on White-tailed Deer (Odocoileus virginianus), one of the Wolfs smaller prey, it is evidence that pack size and prey size are not tightly related. It also indicates the size that Wolf packs can attain in the area if fully protected from human persecution.


Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech Jan 2000

Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus) in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut), Canada, was observed during summer 1998, in contrast to most other years since 1986. Evidence of malnourished muskoxen was also found. Early winter weather and a consequent 50% reduction of the 1997 summer replenishment period appeared to be the most likely cause, giving rise to a new hypothesis about conditions that might cause adverse demographic effects in arctic herbivores.

Durant l’été 1998, et ce, à la différence de la plupart des années depuis …


Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech Jan 2000

Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skuIIs. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionaIIy by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within …


Prolonged Winter Undernutrition And The Interpretation Of Urinary Allantoin:Creatinine Ratios In White-Tailed Deer, Glenn D. Delgiudice, Ken D. Kerr, L. David Mech, Ulysses S. Seal Jan 2000

Prolonged Winter Undernutrition And The Interpretation Of Urinary Allantoin:Creatinine Ratios In White-Tailed Deer, Glenn D. Delgiudice, Ken D. Kerr, L. David Mech, Ulysses S. Seal

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The urinary allantoin:creatinine (A:C) ratio (expressed in micromoles of allantoin to micromoles of creatinine) has shown potential as an index of recent winter energy intake in preliminary controlled studies of elk (Cervus elaphus) involving mild condition deterioration (up to 11% loss of body mass). To ensure reliable nutritional assessments of free-ranging cervids by measuring A:C ratios of urine in snow, it is essential to extend this work. We assessed the effect of moderate and severe winter nutritional restriction on urinary A:C ratios of captive white-tailed deer (Odocoileus virginianus) that lost up to 32% body mass and …


Baseline Assessment Of The Use Of A Small Missouri River Backwater By Fish At Ponca State Park In Dixon County, Nebraska, A. Luke Wallace Jan 2000

Baseline Assessment Of The Use Of A Small Missouri River Backwater By Fish At Ponca State Park In Dixon County, Nebraska, A. Luke Wallace

United States Army Corps of Engineers, Omaha District

Ponca State Park is located adjacent to the Missouri River near the town of Ponca in Dixon County, Nebraska between river miles 753.8 and 755.3. This portion of the river is a 59-mile, unchannelized segment that has been designated as the Missouri National Recreational River under the Wild and Scenic Rivers Act. The majority of the park is situated high on bluffs that overlook the Missouri River. Until recently, the park had only a small amount of easily accessible river frontage. In 1999, the Nebraska Game and Parks Commission (NGPC) acquired an additional 295 acres of river bottomland on the …


Waterfowl Research Priorities In The Northern Great Plains, Robert R. Cox Jr., Douglas H. Johnson, Michael A. Johnson, Ronald E. Kirby, Jeffrey W Nelson, Ronald E. Reynolds Jan 2000

Waterfowl Research Priorities In The Northern Great Plains, Robert R. Cox Jr., Douglas H. Johnson, Michael A. Johnson, Ronald E. Kirby, Jeffrey W Nelson, Ronald E. Reynolds

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

It is necessary periodically to identify research priorities so that future research will be directed toward the most pertinent issues in waterfowl ecology and management. To that end, Northern Prairie Wildlife Research Center convened a quorum of experts on the ecology of breeding waterfowl, the Waterfowl Working Group, to 1) develop a mission statement, 2) identify waterfowl research priorities in the northern Great Plains, and 3) determine the frequency for re-identifying research needs. Research needs (nonprioritized) identified by the group and described in detail herein included: 1) determine effects of landscape factors on demographics and recruitment of ducks in the …


Temporal Flexibility Of Reproduction In Temperate-Breeding Dabbling Ducks, Gary Krapu Jan 2000

Temporal Flexibility Of Reproduction In Temperate-Breeding Dabbling Ducks, Gary Krapu

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

I compared nesting intervals during three consecutive years in five species of temperate-nesting dabbling ducks (Mallard [Anas platyrhynchos], Northern Pintail [Anas acuta], Northern Shoveler [Anas clypeata], Blue-winged Teal [Anas discors], Gadwall [Anas strepera]) and assessed whether differences existed in timing of refractoriness. Most nesting by females of all five species ended by the summer solstice. Nesting ended earliest for Northern Shovelers and Northern Pintails and latest for Gadwalls. Some Mallards, Blue-winged Teal, and Gadwalls continued to nest into mid- and late summer, whereas Northern Shovelers and Northern Pintails did not. …


Habitat Erosion Protection Analysis Missouri National Recreational River Nebraska And South Dakota Jan 2000

Habitat Erosion Protection Analysis Missouri National Recreational River Nebraska And South Dakota

United States Army Corps of Engineers, Omaha District

The Corps was tasked by the National Park Service to detennine if erosion protection measures were needed to prevent further decline in cottonwood forest within the Missouri National Recreational River. The 1990's had three unusually high water years resulting in increased runoff and dam discharges, with resultant increased erosion. Concern about erosion of cottonwood forests was expressed by the public during public meetings held by the National Park Service and the Corps during 1999. Severe erosion was also evident in the comparison of aerial maps from 1985 to those from 1997. Forested habitat is considered a "wildlife value" for the …


Wolf-Bison Interactions In Yellowstone National Park, Douglas Smith, L. David Mech, Mary Meagher, Wendy Clark, Rosemary Jaffe, Michael Phillips, John A. Mack Jan 2000

Wolf-Bison Interactions In Yellowstone National Park, Douglas Smith, L. David Mech, Mary Meagher, Wendy Clark, Rosemary Jaffe, Michael Phillips, John A. Mack

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

We studied interactions of reintroduced wolves (Canis lupus) with bison (Bison bison) in Yellowstone National Park. Only 2 of 41 wolves in this study had been exposed to bison before their translocation. Wolves were more successful killing elk (Cervus elaphus) than bison, and elk were more abundant than bison, so elk were the primary prey of wolves. Except for a lone emaciated bison calf killed by 8 1-year-old wolves 21 days after their release, the 1st documented kill occurred 25 months after wolves were released. Fourteen bison kills were documented from April 1995 through …


Aquatic Dissipation Of The Herbicide Triclopyr In Lake Minnetonka, Minnesota, Kurt D. Getsinger, David G. Petty, John D. Madsen, John G. Skogerboe, Bruce A. Houtman, William T. Haller, Alison M. Fox Jan 2000

Aquatic Dissipation Of The Herbicide Triclopyr In Lake Minnetonka, Minnesota, Kurt D. Getsinger, David G. Petty, John D. Madsen, John G. Skogerboe, Bruce A. Houtman, William T. Haller, Alison M. Fox

United States Army Corps of Engineers, Omaha District

A study of the aquatic fate of the triethylamine salt of triclopyr (3,5,6-trichloro-2- pyridinyloxyacetic acid) was conducted in three bays of Lake Minnetonka, Minnesota. Triclopyr is under review by the US Environmental Protection Agency as a selective aquatic herbicide. The primary purpose of this study was to determine dissipation rates of the parent active ingredient, triclopyr, and its major metabolites, 3,5,6-trichloropyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) in selected matrices including water, sediment, plants, finfish and shellfish. Two 6.5- ha plots dominated by the weedy species Eurasian watermilfoil (Myriophyllum spicatum L) were treated with triclopyr-triethylammonum at a rate of 2.5mg AE liter …


Two-Groups With Few Conjugacy Classes, Nigel Boston, Judy L. Walker Jan 2000

Two-Groups With Few Conjugacy Classes, Nigel Boston, Judy L. Walker

Department of Mathematics: Faculty Publications

An old question of Brauer asking how fast numbers of conjugacy classes grow is investigated by considering the least number cn of conjugacy classes in a group of order 2n. The numbers cn are computed for n ≤ 14 and a lower bound is given for c15. It is observed that cn grows very slowly except for occasional large jumps corresponding to an increase in coclass of the minimal groups Gn. Restricting to groups that are 2-generated or have coclass at most 3 allows us to extend these computations.


Environmental Ethical Decision Making In The U.S. Metal-Finishing Industry, Brenda L. Flannery, Douglas R. May Jan 2000

Environmental Ethical Decision Making In The U.S. Metal-Finishing Industry, Brenda L. Flannery, Douglas R. May

Department of Management: Faculty Publications

We investigated the individual and contextual influences shaping the environmental ethical decision intentions of a sample of managers in the U.S. metal-finishing industry in this study. Ajzen's (1991) theory of planned behavior and Jones's (1991) moral intensity construct grounded our theoretical framework. Findings revealed that the magnitude of consequences, a dimension of moral intensity, moderated the relation- ships between each of five antecedents-attitudes, subjective norms, and three perceived behavioral control factors (self-efficacy, financial cost, and ethical climate)- and managers' environmental ethical decision intentions. We then developed implications for theory and practice in environmental ethical decision making.


The Impact Of Culture On Feedback-Seeking Behavior: An Integrated Model And Propositions, Mary Frances Sully De Luque, Steven M. Sommer Jan 2000

The Impact Of Culture On Feedback-Seeking Behavior: An Integrated Model And Propositions, Mary Frances Sully De Luque, Steven M. Sommer

Department of Management: Faculty Publications

In recent research scholars have addressed the issue of an individual's behavior in feedback-seeking activity and, except in scant studies, have virtually ignored the role of culture in this area. In this article we explore four cultural syndromes, based on past research, to form a cross-cultural model of feedback-seeking behavior. We advance propositions for the study of culture as a moderator to feedback-seeking behavior.


Translation Theorems For Fourier-Feynman Transforms And Conditional Fourier-Feynman Transforms, Seung Jun Change, Chull Park, David Skough Jan 2000

Translation Theorems For Fourier-Feynman Transforms And Conditional Fourier-Feynman Transforms, Seung Jun Change, Chull Park, David Skough

Department of Mathematics: Faculty Publications

Translation theorems for Wiener integrals were given by Cameron and Martin in [3] and by Cameron and Graves in [2]. Translation theorems for analytic Feynman integrals were given by Cameron and Storvick in [4], [7] and translation theorems for Feynman integrals on abstract Wiener and Hilbert spaces were given by Chung and Kang in [12].


The State And Future Of Mars Polar Science And Exploration, Stephen M. Clifford, David Crisp, David A. Fisher, Ken E. Herkenhoff, Suzanne E. Smrekar, Peter C. Thomas, David D. Wynn-Williams, Richard W. Zurek, Jeffrey R. Barnes, Bruce G. Bills, Erik W. Blake, Wendy M. Calvin, Jonathan M. Cameron, Michael H. Carr, Philip R. Christensen, Benton C. Clark, Gary D. Clow, James A. Cutts, Dorthe Dahl-Jensen, William B. Durham, Fraser P. Fanale, Jack D. Farmer, Francois Forget, Kumiko Gotto-Azuma, Rejean Grard, Robert M. Haberle, William Harrison, Ralph Harvey, Alan D. Howard, Andy P. Ingersoll, Philip B. James, Jeffrey S. Kargel, Hugh H. Kieffer, Janus Larsen, Kenneth Lepper, Michael C. Malin, Daniel J. Mccleese, Bruce Murray, John F. Nye, David A. Paige, Stephen R. Platte, Jef F J. Plaut, Niels Reeh, James W. Rice, David E. Smith, Carol R. Stoker, Kenneth L. Tanaka, Ellen Mosley-Thompson, Thorsteinn Thorsteinsson, Stephen E. Wood, Aaron Zent, Maria T. Zuber, H. Jay Zwally Jan 2000

The State And Future Of Mars Polar Science And Exploration, Stephen M. Clifford, David Crisp, David A. Fisher, Ken E. Herkenhoff, Suzanne E. Smrekar, Peter C. Thomas, David D. Wynn-Williams, Richard W. Zurek, Jeffrey R. Barnes, Bruce G. Bills, Erik W. Blake, Wendy M. Calvin, Jonathan M. Cameron, Michael H. Carr, Philip R. Christensen, Benton C. Clark, Gary D. Clow, James A. Cutts, Dorthe Dahl-Jensen, William B. Durham, Fraser P. Fanale, Jack D. Farmer, Francois Forget, Kumiko Gotto-Azuma, Rejean Grard, Robert M. Haberle, William Harrison, Ralph Harvey, Alan D. Howard, Andy P. Ingersoll, Philip B. James, Jeffrey S. Kargel, Hugh H. Kieffer, Janus Larsen, Kenneth Lepper, Michael C. Malin, Daniel J. Mccleese, Bruce Murray, John F. Nye, David A. Paige, Stephen R. Platte, Jef F J. Plaut, Niels Reeh, James W. Rice, David E. Smith, Carol R. Stoker, Kenneth L. Tanaka, Ellen Mosley-Thompson, Thorsteinn Thorsteinsson, Stephen E. Wood, Aaron Zent, Maria T. Zuber, H. Jay Zwally

Department of Mechanical and Materials Engineering: Faculty Publications

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of ~106 km2 and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young-preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past ~105-108 years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of …


Colonial Violence And Trauma In The Works Of Michèle Lacrosil And Ken Bugul, Marie-Chantal Kalisa Jan 2000

Colonial Violence And Trauma In The Works Of Michèle Lacrosil And Ken Bugul, Marie-Chantal Kalisa

French Language and Literature Papers

To what extent can we say that both Lacrosil and Bugul rewrite Fanon? Through the study of Cajou and Ken, respectively the Guadeloupean and the Senegalese female protagonists, this article proposes a way to derive a specifically female perspective on colonial violence. The essay focuses on the two novels, Cajou and Le baobab fou, and examines the effect of colonial epistemological violence and its specific impact on the black female’s subjectivity. The protagonists Ken and Cajou revisit their initial trauma in a quest for knowledge of their historical heritage and engage in a dialogue with Frantz Fanon, representative of black …


The Role Of Chitinase Production By Stenotrophomonas Maltophilia Strain C3 In Biological Control Of Bipolaris Sorokiniana, Zhongge Zhang, Gary Y. Yuen Jan 2000

The Role Of Chitinase Production By Stenotrophomonas Maltophilia Strain C3 In Biological Control Of Bipolaris Sorokiniana, Zhongge Zhang, Gary Y. Yuen

Department of Plant Pathology: Faculty Publications

The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into fractions. A high molecular-weight fraction (>8 kDa) was chitinolytic and more inhibitory than a low-molecularweight, nonchitinolytic fraction to conidial germination and hyphal growth by B. sorokiniana and to leaf spot development. A protein fraction derived by ammonium sulfate precipitation and a chitinase fraction purified by chitin affinity …


Soybean Cyst Nematode Reproduction In The North Central United States, J. Wang, P. A. Donald, T. L. Niblack, G. W. Bird, J. Faghihi, J. M. Ferris, C. Grau, D. J. Jardine, P. E. Lipps, A. E. Macguidwin, H. Melakeberhan, G. R. Noel, P. Pierson, P. M. Riedel, P. R. Sellers, W. C. Stienstra, T. C. Todd, G. L. Tylka, T. A. Wheeler, D. S. Wysong Jan 2000

Soybean Cyst Nematode Reproduction In The North Central United States, J. Wang, P. A. Donald, T. L. Niblack, G. W. Bird, J. Faghihi, J. M. Ferris, C. Grau, D. J. Jardine, P. E. Lipps, A. E. Macguidwin, H. Melakeberhan, G. R. Noel, P. Pierson, P. M. Riedel, P. R. Sellers, W. C. Stienstra, T. C. Todd, G. L. Tylka, T. A. Wheeler, D. S. Wysong

Department of Plant Pathology: Faculty Publications

An experiment was conducted in Heterodera glycines–infested fields in 40 north central U.S. environments (21 sites in 1994 and 19 sites in 1995) to assess reproduction of this nematode. Two resistant and two susceptible soybean cultivars from each of the maturity groups (MG) I through IV were grown at each site in 6.1 m by 4 row plots. Soil samples were collected from each plot at planting and harvest and processed at Iowa State University to determine H. glycines initial (Pi) and final (Pf) population densities as eggs per 100 cm3 of soil. Overall, reproduction (Pf/Pi) of H. glycines …


Isovolumic Regulation In Nervous Tissue: A Novel Mechanism Of Cell Volume Regulation, O. Quesada, R. Franco, K. Hernandez-Fonseca, K. Tuz Jan 2000

Isovolumic Regulation In Nervous Tissue: A Novel Mechanism Of Cell Volume Regulation, O. Quesada, R. Franco, K. Hernandez-Fonseca, K. Tuz

School of Veterinary and Biomedical Sciences: Faculty Publications

Cell volume regulation is a property present in most animal cell lineages that allows them to recover their original volume after events of swelling or shrinkage. Such events can be caused by changes in external osmolarity or to osmotic gradients generated during normal cell functioning.4,6 The mechanism of cell volume regulation involves transmembrane fluxes of osmotically active solutes in the necessary direction to counteract the net gain or loss of intracellular water.9 The process through which cells recover their normal volume after swelling is named Regulatory Volume Decrease (RVD). This consists of the efflux of inorganic osmolytes, such as K …


Bayesian Spectrum Analysis For Laser Vibrometry Processing, Walter F. Buell, Bradley Allan Shadwick, Robert W. Farley Jan 2000

Bayesian Spectrum Analysis For Laser Vibrometry Processing, Walter F. Buell, Bradley Allan Shadwick, Robert W. Farley

Department of Physics and Astronomy: Faculty Publications

Laser vibration sensing provides a sensitive non-contact means of measuring vibrations of objects. These measurements are used in industrial quality control and wear monitoring as well as the analysis of the vibrational characteristics of objects. In laser vibrometry, the surface motion is monitored by heterodyne laser Doppler velocimetry, and the received heterodyne signal is sampled to produce a time-series which is processed to obtain a vibrational spectrum of the object under test. Laser vibrometry data has been processed with a traditional FM discriminator approach and by spectrogram and time-frequency distribution processing techniques. The latter techniques have demonstrated improved performance over …


High Coercivity Longitudinal Recording Media And Method For Its Preparation, David J. Sellmyer, Chun-Ping Luo Jan 2000

High Coercivity Longitudinal Recording Media And Method For Its Preparation, David J. Sellmyer, Chun-Ping Luo

Department of Physics and Astronomy: Faculty Publications

A high coercivity longitudinal recording media comprising FePt or similar thin films that are vacuum deposited by RF and DC sputtering. The as-deposited multilayerd films are subjected to vacuum annealing. Due to the formation of the ordered phases of FePt or the like, which have very high crystal anisotropy, the annealed FePt films have large coercivity and fine grain size, suitable for use as ultra-high density magnetic recording media.


Interaction Of Laser Radiation With A Negative Ion In The Presence Of A Strong Static Electric Field, N. L. Manakov, M. V. Frolov, Anthony F. Starace, Ilya I. Fabrikant Jan 2000

Interaction Of Laser Radiation With A Negative Ion In The Presence Of A Strong Static Electric Field, N. L. Manakov, M. V. Frolov, Anthony F. Starace, Ilya I. Fabrikant

Anthony F. Starace Publications

This paper provides a general theoretical description of a weakly bound atomic system (a negative ion) interacting simultaneously with two (generally strong) fields, a static electric field and a monochromatic laser field having an arbitrary elliptical polarization. The zero-range δ-potential is used to model the interaction of a bound electron in a negative ion as well as the interaction of a detached electron with the residual atom. Our treatment combines the quasistationary (complex energy) and quasienergy (Floquet) approaches. This quasistationary, quasienergy state (QQES) formalism is the most appropriate one for analysing a decaying quantum system under the influence of a …


Excitation And Damping Of A Self-Modulated Laser Wakefield, Shouyuan Chen, M. Krishnan, Anatoly Maksimchuk, Donald P. Umstadter Jan 2000

Excitation And Damping Of A Self-Modulated Laser Wakefield, Shouyuan Chen, M. Krishnan, Anatoly Maksimchuk, Donald P. Umstadter

Donald Umstadter Publications

Spatially, temporally, and angularly resolved collinear collective Thomson scattering was used to diagnose the excitation and damping of a relativistic-phase-velocity self-modulated laser wakefield. The excitation of the electron plasma wave was observed to be driven by Raman-type instabilities. The damping is believed to originate from both electron beam loading and modulational instability. The collective Thomson scattering of a probe pulse from the ion acoustic waves, resulting from modulational instability, allows us to measure the temporal evolution of the plasma temperature. The latter was found to be consistent with the damping of the electron plasma wave.


Electronic Scattering From Co/Cu Interfaces: In-Situ Measurement And Comparison With Theory, W. E. Bailey, Shan X. Wang, Evgeny Y. Tsymbal Jan 2000

Electronic Scattering From Co/Cu Interfaces: In-Situ Measurement And Comparison With Theory, W. E. Bailey, Shan X. Wang, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

The full thickness-dependent electrical conductivity of polycrystalline NiO/Co/Cu/Co spin-valve structures was measured in situ during ion-beam deposition and compared with calculations based on realistic band structure. We have found striking features in the experimental conductivity which are unexpected from widely used semiclassical free-electron models. Addition of ∼ 1 ML Co to a NiO/Co/Cu surface causes the net film conductance to decrease; the reverse case of Cu on NiO/Co shows a strong positive curvature of the thicknessdependent conductance, indicating a reduction of the conductivity in Cu near the interface with Co. Quantitative agreement is found between the experimental thickness-dependent film conductance …


Nest Predation On Black-Tailed Prairie Dog Colonies, Bruce Baker, Thomas R. Stanley, Glenn Plumb Jan 2000

Nest Predation On Black-Tailed Prairie Dog Colonies, Bruce Baker, Thomas R. Stanley, Glenn Plumb

United States Geological Survey: Staff Publications

Nest predation is the principal cause of mortality for many grassland birds. Predation rates may be higher on prairie dog colonies because they may have less available nesting cover and may increase predator abundance. We compared 14-day nest predation rates for 1,764 artificial nests on 102 black-tailed prairie dog (Cynovnys ludovicianus) colonies and their paired off-colony sites (similar habitat lacking prairie dogs) from 14 May to 26 June 1998 in South Dakota and Wyoming. Predation rates on colonies (66.2 ± 2.2%; x ± SE) were 29.5% higher than at off-colony sites (51.1 ± 2.7%). Nesting cover on colonies …


Multivariate Correlation Between Concentrations Of Selected Herbicides And Derivatives In Outflows From Selected U.S. Midwestern Reservoirs, R. Tauler, D. Barcelo, E. Michael Thurman Jan 2000

Multivariate Correlation Between Concentrations Of Selected Herbicides And Derivatives In Outflows From Selected U.S. Midwestern Reservoirs, R. Tauler, D. Barcelo, E. Michael Thurman

United States Geological Survey: Staff Publications

Multivariate correlations between the concentrations of selected herbicides and herbicide derivatives in outflows from selected reservoirs in the Midwestern United States for April 1992 through September 1993 were investigated using principal component analysis (PCA) and multivariate curve resolution (MCR). Two independent sources for alachlor ethanesulfonic acid, one major source related to spring flush and seasonal runoff and another minor source related to groundwater, were identified using PCA. Results of MCR provided a semiquantitative interpretation of the environmental sources of the observed herbicide concentrations in reservoir outflows and allowed the examination of their temporal and geographical distributions. Samples with higher herbicide …


Geochemical And Mineralogical Evidence From Eolian Sediments For Northwesterly Mid-Holocene Paleowinds, Central Kansas, Usa, Alan F. Arbogast, Daniel R. Muhs Jan 2000

Geochemical And Mineralogical Evidence From Eolian Sediments For Northwesterly Mid-Holocene Paleowinds, Central Kansas, Usa, Alan F. Arbogast, Daniel R. Muhs

United States Geological Survey: Staff Publications

A prominent (4500 km2) dune field in the Great Plains is the Great Bend Sand Prairie of south-central Kansas. Dunes here overlie late Quaternary alluvium and were reactivated extensively in the late Holocene. Geomorphic and soil evidence suggests that the most likely eolian sand source is the Arkansas River valley to the northwest. Nevertheless, orientations of stabilized dunes indicate that the most recent dune-forming winds came from the south or southwest, in agreement with modern wind data.

Mineralogy and trace element concentrations in eolian sands of the Great Bend Sand Prairie are similar to those of the Arkansas …


Using A Nitrate Specific Ion Electrode To Determine Stalk Nitrate–Nitrogen Concentration, Wallace Wilhelm, S.L. Arnold, James S. Schepers Jan 2000

Using A Nitrate Specific Ion Electrode To Determine Stalk Nitrate–Nitrogen Concentration, Wallace Wilhelm, S.L. Arnold, James S. Schepers

Department of Agronomy and Horticulture: Faculty Publications

The end-of-season stalk NO3 test has been used to determine N sufficiency in corn (Zea mays L.). Nitrate concentration is commonly determined with flow-injection analysis (FIA), which is accurate but uses hazardous chemicals and is time-consuming. Use of a simpler method of NO3 determination, such as the NO3 specific ion electrode (SIE), may save time and costs, and reduce hazards. The objective of this study was to compare estimates of stalk NO3 concentration by FIA and NO3 SIE. For FIA, NO3 was extracted with 2 M KCl, and the extract was filtered before analysis. …


Establishment Of Big Bluestem And Illinois Bundleflower Mixtures With Imazapic And Imazethapyr, Daniel D. Beran, Robert A. Masters, Roch E. Gaussoin, Fernando Rivas-Pantoja Jan 2000

Establishment Of Big Bluestem And Illinois Bundleflower Mixtures With Imazapic And Imazethapyr, Daniel D. Beran, Robert A. Masters, Roch E. Gaussoin, Fernando Rivas-Pantoja

Department of Agronomy and Horticulture: Faculty Publications

Weeds interfere with establishment of native grasses and legumes. A study was conducted to determine the influence of imazapic1 [(±)- 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]- 5-methyl-3-pyridinecarboxylic acid] and imazethapyr [2-[4,5-dihydro- 4-methyl -4 - (1- methylethyl) -5 -oxo-1H- imidazol -2 - yl]5- ethyl -3- pyridinecarboxylic acid] on weed control and establishment of ‘Pawnee’ big bluestem (Andropogon gerardii Vitman var. gerardii Vitman) and Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMill.] planted in three binary mixtures of 220:110, 165:165, and 110:220 pure live seed (PLS) m-2. Mixtures were seeded at cropland sites near Clay Center, Mead, and Lincoln, NE. Imazapic and imazeth- apyr …


Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance In Soybean Fields Protected And Unprotected By Shelterbelts, Stephen D. Danielson, James R. Brandle, Laurie Hodges, P. Srinivas Jan 2000

Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance In Soybean Fields Protected And Unprotected By Shelterbelts, Stephen D. Danielson, James R. Brandle, Laurie Hodges, P. Srinivas

Department of Agronomy and Horticulture: Faculty Publications

The bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is a major insect pest of soybean in Nebraska and throughout much of the Midwest. This insect overwinters in the adult stage in litter in wooded areas such as shelterbelts. Historically, crop producers have been unsure of the merits of shelterbelts, especially if nearby crops are more likely to be infested by insect pests as a result. In this study, bean leaf beetle adults were sampled during the season by visually counting the number of beetles found on soybean plants early in the season and by sweep net sampling once plants …