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Depositional Environments For Strata Cored In Crp-3 (Cape Roberts Project), Victoria Land Basin, Antarctica: Palaeoglaciological And Palaeoclimatological Inferences, R. D. Powell, M. G. Laird, T. R. Naish, Christopher R. Fielding, L. A. Krissek, J.J. M. Van Der Meer Jan 2001

Depositional Environments For Strata Cored In Crp-3 (Cape Roberts Project), Victoria Land Basin, Antarctica: Palaeoglaciological And Palaeoclimatological Inferences, R. D. Powell, M. G. Laird, T. R. Naish, Christopher R. Fielding, L. A. Krissek, J.J. M. Van Der Meer

Department of Earth and Atmospheric Sciences: Faculty Publications

Cape Roberts Project drill core 3 (CRP-3) was obtained from Roberts ridge, a sea-floor high located at 77oS, 12 km offshore from Cape Roberts in western McMurdo Sound, Antarctica. The recovered core is about 939 m long and comprises strata dated as being early Oligocene (possibly latest Eocene) in age, resting unconformably on ~116 m of basement rocks consisting of Palaeozoic Beacon Supergroup sediments. The core includes ten facies commonly occurring in five major associations that are repeated in particular sequences throughout the core and which are interpreted as representing different depositional environments through time. Depositional systems inferred …

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Mitochondrial Phylogeography, Subspecific Taxonomy, And Conservation Genetics Of Sandhill Cranes (Grus Canadensis; Aves: Gruidae), Judith M. Rhymer, Matthew G. Fain, Jane E. Austin, Douglas H. Johnson, Carey Krajewski Jan 2001

Mitochondrial Phylogeography, Subspecific Taxonomy, And Conservation Genetics Of Sandhill Cranes (Grus Canadensis; Aves: Gruidae), Judith M. Rhymer, Matthew G. Fain, Jane E. Austin, Douglas H. Johnson, Carey Krajewski

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

Six subspecies of sandhill cranes (Grus canadensis) have been denoted based on perceived morphological and/or breeding locality differences among them. Three subspecies are migratory, breeding from the high arctic in North America and Siberia (lesser sandhill, G. c. canadensis), south through central Canada (Canadian sandhill, G. c. rowani) and into the northern United States (greater sandhill, G. c. tabida). A review of sandhill crane taxonomy indicates that the size variation, on the basis of which these subspecies were named, may be clinal and not diagnostic. The other three subspecies, all listed as endangered or threatened, …

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Use Of Macroinvertebrates To Identify Cultivated Wetlands In The Prairie Pothole Region, Ned H. Euliss Jr., David M. Mushet, Douglas H. Johnson Jan 2001

Use Of Macroinvertebrates To Identify Cultivated Wetlands In The Prairie Pothole Region, Ned H. Euliss Jr., David M. Mushet, Douglas H. Johnson

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

We evaluated the use of macroinvertebrates as a potential tool to identify dry and intensively farmed temporary and seasonal wetlands in the Prairie Pothole Region. The techniques we designed and evaluated used the dried remains of invertebrates or their egg banks in soils as indicators of wetlands. For both the dried remains of invertebrates and their egg banks, we weighted each taxon according to its affinity for wetlands or uplands. Our study clearly demonstrated that shells, exoskeletons, head capsules, eggs, and other remains of macroinvertebrates can be used to identify wetlands, even when they are dry, intensively farmed, and difficult …

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Human Herpesvirus 8 Can Be Transmitted Through Blood In Drug Addicts, Carlos Sosa, Jorge Benetucci, Colleen Hanna, Laura Sieczkowski, Gabriel Deluchi, Ana Maria Canizal, Hamakwa Mantina, Winslow Klaskala, Marianna Baum, Charles Wood Jan 2001

Human Herpesvirus 8 Can Be Transmitted Through Blood In Drug Addicts, Carlos Sosa, Jorge Benetucci, Colleen Hanna, Laura Sieczkowski, Gabriel Deluchi, Ana Maria Canizal, Hamakwa Mantina, Winslow Klaskala, Marianna Baum, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human Herpes virus type-8 (HHV-8) seroprevalence was studied in a population of HIV positive intravenous drug users (IVDUs) from Argentina. Analysis of this population also indirectly made it possible to study HHV-8 blood transmission, because these individuals frequently engage in needle sharing behavior and are capable of acquiring a broad array of blood borne pathogens, including Hepatitis B/C virus. The seroprevalence of HHV-8 in IVDUs was compared to a group of non-IVDUs and HIV negative individuals. Of the 223 individuals tested, 13.45% were HHV-8 positive, 16.99% in the IVDUs group, and 5.71% in the non-IVDUs. Among HIV positive IVDUs, 25/144 …

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Implementation Of The Biological Opinion For The Missouri River Main Stem System, Missouri River Bank Stabilization And Navigation Project, And Kansas River Reservoir System Jan 2001

Implementation Of The Biological Opinion For The Missouri River Main Stem System, Missouri River Bank Stabilization And Navigation Project, And Kansas River Reservoir System

United States Army Corps of Engineers, Omaha District

The Endangered Species Act (ESA) requires that the Corps of Engineers (Corps), in coordination with the appropriate resources agency, will ensure that any action authorized, funded, or carried out is not likely to jeopardize the continued existence of any federally listed threatened or endangered species or result in the destruction or adverse modification of critical habitat. Formal consultation between the U.S. Fish and Wildlife Service (FWS) and the Corps under Section 7 of the ESA culminated with the "Biological Opinion on the Operation of the Missouri River Main Stem System, Operation and Maintenance of the Missouri River Bank Stabilization and …

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Duck Populations As Indicators Of Landscape Condition In The Prairie Pothole Region, Jane Austin, Thomas K. Buhl, Glenn R. Guntenspergen, Wayne Norling, H. Thomas Sklebar Jan 2001

Duck Populations As Indicators Of Landscape Condition In The Prairie Pothole Region, Jane Austin, Thomas K. Buhl, Glenn R. Guntenspergen, Wayne Norling, H. Thomas Sklebar

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

The Prairie Pothole Region of the northern Great Plains is an important region for waterfowl production because of the abundance of shallow wetlands. The ecological significance of the region and impacts from intensive agriculture prompted the U.S. Environmental Protection Agency to select it as one of the first areas for developing and evaluating ecological indicators of wetland condition. We examined hypothesized relations between indicators of landscape and wetland conditions and waterfowl abundance on 45 40 km2 study sites in North Dakota for 1995–1996. Landscape condition was defined a priori as the ratio of cropland area to total upland area …

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Evaluation Of The Bird Conservation Area Concept In The Northern Tallgrass Prairie: Annual Report 2001, Maiken Winter, Douglas H. Johnson, Jill A. Dechant, Therese M. Donovan, W. Daniel Svedarsky Jan 2001

Evaluation Of The Bird Conservation Area Concept In The Northern Tallgrass Prairie: Annual Report 2001, Maiken Winter, Douglas H. Johnson, Jill A. Dechant, Therese M. Donovan, W. Daniel Svedarsky

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

In 1998 we initiated a test of the concept that Bird Conservation Areas (BCA's) can maintain populations of breeding grassland birds. The underlying hypothesis is that large core areas of quality habitat (such as native prairie) that are surrounded by neutral habitats (such as small-grain fields), and that are isolated from hostile habitats (such as woody vegetation) will result in avian densities and reproductive rates sufficient to at least maintain population levels of breeding birds. This concept was proposed by the Midwest Working Group of Partners In Flight (e.g., Pashley and Fitzgerald 1996) and endorsed also by the Prairie Pothole …

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Fluvial Processes And Passive Rehabilitation Of The Lisbon Bottom Side-Channel Chute, Lower Missouri River, Robert B. Jacobson, Mark S. Laustrup, Michael D. Chapman Jan 2001

Fluvial Processes And Passive Rehabilitation Of The Lisbon Bottom Side-Channel Chute, Lower Missouri River, Robert B. Jacobson, Mark S. Laustrup, Michael D. Chapman

United States Army Corps of Engineers, Omaha District

Multiple large floods in 1993-1997 on the Lower Missouri River carved a side-channel chute through the river bottom at Lisbon, Missouri. Although similar in some respects to engineered side-channel chutes designed for habitat rehabilitation projects, the Lisbon Bottom chute has been unique in that it was allowed to evolve for more than four years with minimal stabilization. During the wet years, 1996-1999, the chute was subjected to abnormally high discharges and passed as much as 20% of the total discharge of the Missouri River. Relatively unrestrained fluvial processes during this time created a wide channel with highly diverse habitats. The …

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Effects Of Management Practices On Grassland Birds: Bobolink, Jill A. Dechant, Marriah L. Sondreal, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Amy L. Zimmerman, Betty R. Euliss Jan 2001

Effects Of Management Practices On Grassland Birds: Bobolink, Jill A. Dechant, Marriah L. Sondreal, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Amy L. Zimmerman, Betty R. Euliss

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

Bobolink (Dolichonyx oryzivorus):
Breeding range
Suitable habitat
Area requirements
Brown-headed Cowbird brood parasitism
Breeding-season phenology and site fidelity
Species’ response to management
Management Recommendations
Characteristics

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Estimated Areal Extent Of Colonies Of Black-Tailed Prairie Dogs In The Northern Great Plains, John Sidle, Douglas Johnson, Betty Euliss Jan 2001

Estimated Areal Extent Of Colonies Of Black-Tailed Prairie Dogs In The Northern Great Plains, John Sidle, Douglas Johnson, Betty Euliss

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

During 1997-1998, we undertook an aerial survey, with an aerial line-intercept technique, to estimate the extent of colonies of black-tailed prairie dogs (Cynomys ludovicianus) in the northern Great Plains states of Nebraska, North Dakota, South Dakota, and Wyoming. We stratified the survey based on knowledge of colony locations, computed 2 types of estimates for each stratum, and combined ratio estimates for high-density strata with average density estimates for low-density strata. Estimates of colony areas for black-tailed prairie dogs were derived from the average percentages of lines intercepting prairie dog colonies and ratio estimators. We selected the best estimator …

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Effects Of Management Practices On Grassland Birds: Sprague’S Pipit, Jill A. Dechant, Marriah L. Sondreal, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Melvin P. Nenneman, Betty R. Euliss Jan 2001

Effects Of Management Practices On Grassland Birds: Sprague’S Pipit, Jill A. Dechant, Marriah L. Sondreal, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Melvin P. Nenneman, Betty R. Euliss

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

Sprague’s Pipit (Anthus spragueii):
Breeding range
Suitable habitat
Area requirements
Brown-headed Cowbird brood parasitism
Breeding-season phenology and site fidelity
Species’ response to management
Management Recommendations
Habitat Characteristics

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Effects Of Management Practices On Grassland Birds: Marbled Godwit, Jill A. Dechant, Marriah L. Sondreal, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Melvin P. Nenneman, Betty R. Euliss Jan 2001

Effects Of Management Practices On Grassland Birds: Marbled Godwit, Jill A. Dechant, Marriah L. Sondreal, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Melvin P. Nenneman, Betty R. Euliss

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

Marbled Godwit (Limosa fedoa):
Breeding range
Suitable habitat
Area requirements
Brown-headed Cowbird brood parasitism
Breeding-season phenology and site fidelity
Species’ response to management
Management Recommendations
Habitat Characteristics

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Fungal Symbiosis From Mutualism To Parasitism: Who Controls The Outcome, Host Or Invader?, Regina S. Redman, David Dunigan, Rusty J. Rodriguez Jan 2001

Fungal Symbiosis From Mutualism To Parasitism: Who Controls The Outcome, Host Or Invader?, Regina S. Redman, David Dunigan, Rusty J. Rodriguez

Department of Plant Pathology: Faculty Publications

• Plant symbiotic fungi are generally thought to express a single lifestyle that might increase (mutualism), decrease (parasitism), or have no influence (commensalism) on host fitness. However, data are presented here demonstrating that plant pathogenic Colletotrichum species are able to asymptomatically colonize plants and express nonpathogenic lifestyles.

• Experiments were conducted in growth chambers and plant colonization was assessed by emergence of fungi from surface sterilized plant tissues. Expression of symbiotic lifestyles was assessed by monitoring the ability of fungi to confer disease resistance, drought tolerance and growth enhancement.

• Several pathogenic Colletotrichum species expressed either mutualistic or commensal lifestyles …

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The Aspergillus Nidulans Snt Genes Are Required For The Regulation Of Septum Formation And Cell Cycle Checkpoints, Peter R. Kraus, Steven D. Harris Jan 2001

The Aspergillus Nidulans Snt Genes Are Required For The Regulation Of Septum Formation And Cell Cycle Checkpoints, Peter R. Kraus, Steven D. Harris

Department of Plant Pathology: Faculty Publications

In Aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before forming a septum. Previous genetic results suggest that the ability to separate nuclear division and septum formation depends upon a threshold level of activity of the cyclin-dependent kinase NIMXcdk1. Mutations in nimX and nimT, the gene encoding the NIMXcdk1-activating phosphatase, have revealed that Tyr-15 phosphorylation is important for determining the timing of the formation of the first septum. Here, we describe a screen for suppressors of nimT23 (snt), designed to identify additional components of the pathway regulating septum formation. We show that a subset …

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Age-Related Resistance In Bell Pepper To Cucumber Mosaic Virus , Hernan Garcia-Ruiz, John F. Murphy Jan 2001

Age-Related Resistance In Bell Pepper To Cucumber Mosaic Virus , Hernan Garcia-Ruiz, John F. Murphy

Department of Plant Pathology: Faculty Publications

We demonstrated the occurrence of mature plant resistance in Capsicum annuum 'Early Calwonder' to Cucumber mosaic virus (CMV) under greenhouse conditions. When Early Cal wonder plants were sown at 10 day intervals and transplanted to 10-cm square pots, three distinct plant sizes were identified that were designated small, medium and large. Trials conducted during each season showed that CMV accumulated in inoculated leaves of all plants of each size category. All small plants (with the exception of the winter trial) developed a systemic infection that included accumulation of CMV in uninoculated leaves and severe systemic symptoms. Medium plants had a …

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Interferon Regulatory Factor 7 Mediates Activation Of Tap-2 By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagano Jan 2001

Interferon Regulatory Factor 7 Mediates Activation Of Tap-2 By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Transporter associated with antigen processing 2 (Tap-2) is responsible for ATP-dependent transport of peptides from the cytosol to the endoplasmic reticulum, where peptides bind to newly synthesized human leukocyte antigen (HLA) class I molecules, which are essential for cellular immune responses. Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) has been shown to induce the expression of Tap-2. In this study, the induction of endogenous Tap-2 by LMP-1 is shown to be associated with and requires the expression of interferon regulatory factor 7 (IRF-7). In DG75 Burkitt’s lymphoma (BL) cells, in which LMP-1 induces the expression of IRF-7, LMP-1 induced …

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Experimental Infection Of Nontarget Species Of Rodents And Birds With Brucella Abortus Strain Rb51 Vaccine, Matt C. Januszewski, Steven C. Olsen, Robert G. Mclean, Larry Clark, Jack C. Rhyan Jan 2001

Experimental Infection Of Nontarget Species Of Rodents And Birds With Brucella Abortus Strain Rb51 Vaccine, Matt C. Januszewski, Steven C. Olsen, Robert G. Mclean, Larry Clark, Jack C. Rhyan

United States Department of Agriculture Wildlife Services: Staff Publications

The Brucella abortus vaccine strain RB51 (SRB51) is being considered for use in the management of brucellosis in wild bison (Bison bison) and elk (Cervus elaphus) populations in the Greater Yellowstone Area (USA). Evaluation of the vaccine’s safety in non-target species was considered necessary prior to field use. Between June 1998 and December 1999, ground squirrels (Spermophilus richardsonii, n=21), deer mice (Peromyscus maniculatus, n=14), prairie voles (Microtus ochrogaster, n=21), and ravens (Corvus corax, n=13) were orally inoculated with SRB51 or physiologic saline. Oral and …

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Performance Of Intercom For Predicting Corn– Velvetleaf Interference Across North-Central United States, John L. Lindquist Jan 2001

Performance Of Intercom For Predicting Corn– Velvetleaf Interference Across North-Central United States, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Cost-effective weed management requires accurate estimates of yield and the potential yield loss resulting from weed infestations. However, crop yield and the effects of weeds are highly variable across years and locations. Ecophysiological models may be useful for predicting the effects of environment and management on crop and weed growth and competitive ability. Ability of the model INTERCOM to predict corn (Zea mays) growth and yield, velvetleaf (Abutilon theophrasti) interference on corn yield loss, and single-year economic threshold velvetleaf density (Te) was evaluated using 13 data sets collected in four states. Predicted and observed …

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Storage And Handling Characteristics Of Trinexapac-Ethyl Treated Kentucky Bluegrass Sod, Neil L. Heckman, Garald L. Horse, Roch E. Gaussoin, Kevin Frank Jan 2001

Storage And Handling Characteristics Of Trinexapac-Ethyl Treated Kentucky Bluegrass Sod, Neil L. Heckman, Garald L. Horse, Roch E. Gaussoin, Kevin Frank

Department of Agronomy and Horticulture: Faculty Publications

Internal heating during sod storage can lead to plant deterioration and is a limiting factor in sod transportation. Storage practices such as the use of refrigeration and vacuum packaging have increased storage time; however, these are usually not practical or economical. Experiments were conducted to develop a feasible growth regulator management technique, using trinexapac-ethyl, to increase the storage life of Kentucky bluegrass (Poa pratensis L.) sod. Experimental setup for all experiments was a completely randomized design with a 2 (trinexapac-ethyl vs. control) × 3 (storage times) factorial treatment arrangement with 3 replications. Trinexapac-ethyl was applied at 0.23 kg·ha–1 …

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Tillage And Fallow Effects On Selected Soil Quality Characteristics Of Former Conservation Reserve Program Sites, John E. Gilley, John W. Doran, Bahman Eghball Jan 2001

Tillage And Fallow Effects On Selected Soil Quality Characteristics Of Former Conservation Reserve Program Sites, John E. Gilley, John W. Doran, Bahman Eghball

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Tillage and fallow have been suggested as management options for converting Conservation Reserve Program (CRP) areas to cropland. This study was conducted to measure selected soil quality characteristics of former CRP sites in Mississippi, Nebraska, and South Dakota that were tilled and then left fallow for 21 or 22 months. Soil samples from depth intervals of 0-7.6 cm and 0-30.5 cm were collected for laboratory assessment of the following soil quality indicators: bulk density, EC, pH, total C, organic C, total N, NO3-N, NH4-N, PO4-P, biomass C, biomass N, anaerobic NH4-N, lab …

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Phosphorus Risk Assessment Index Evaluation Using Runoff Measurements, Bahman Eghball, John E. Gilley Jan 2001

Phosphorus Risk Assessment Index Evaluation Using Runoff Measurements, Bahman Eghball, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

An index to evaluate the phosphorus (P) pollution potential of agricultural fields was proposed by Lemunyon and Gilbert in 1993. Data from three rainfall simulation studies were used to evaluate the relative importance of the variables in the P index. These studies included plots containing sorghum (Sorghum bicolor L.), winter wheat (Triticum aestivum L.), and corn (Zea mays L.) residues on which chemical fertilizer and composted or noncomposted beef cattle feedlot manure were applied under no-till and disked conditions. The factors of erosion, runoff, soil P level P application source, and method, and rate of P addition …

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Reducing Long-Term Atrazine Runoff From South Central Nebraska, Walter Scott Gorneau, Thomas G. Franti, Brian L. Benham, Steve D. Comfort Jan 2001

Reducing Long-Term Atrazine Runoff From South Central Nebraska, Walter Scott Gorneau, Thomas G. Franti, Brian L. Benham, Steve D. Comfort

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Heavy reliance on chemical weed control in field crops of South Central Nebraska has resulted in the appearance of atrazine at concentrations greater than established drinking water standards. Our objective was to evaluate the best management practices for atrazine runoff for the tillage and herbicide management practices common to the region under study. Field experiments were performed to measure edge–of–field atrazine and water loss from disk–till, ridge–till, and slot plant (no–till) management systems. Results indicated less water runoff from no–till (34% less) and ridge–till (36% less) than from disk–till. Similarly, atrazine loss was also less: 24% less for no–till and …

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Application Of Fuzzy Logic In Automated Cow Status Monitoring, R. M. De Mol, Wayne Woldt Jan 2001

Application Of Fuzzy Logic In Automated Cow Status Monitoring, R. M. De Mol, Wayne Woldt

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Sensors that measure yield, temperature, electrical conductivity of milk, and animal activity can be used for automated cow status monitoring. The occurrence of false-positive alerts, generated by a detection model, creates problems in practice. We used fuzzy logic to classify mastitis and estrus alerts; our objective was to reduce the number of false-positive alerts and not to change the level of detected cases of mastitis and estrus. Inputs for the fuzzy logic model were alerts from the detection model and additional information, such as the reproductive status. The output was a classification, true or false, of each alert. Only alerts …

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Way-Finding And Landmarks: The Multiple Bearings Hypothesis, Alan C. Kamil, Ken Cheng Jan 2001

Way-Finding And Landmarks: The Multiple Bearings Hypothesis, Alan C. Kamil, Ken Cheng

Papers in Behavior in Biological Sciences

Clark’s nutcrackers (Nucifraga columbiana) are capable of very precise searching using the metric relationships between a goal and multiple landmarks to relocate the goal location. They can judge the direction more accurately than the distance to a landmark when the landmark is distant from the goal. On the basis of these findings, we propose that nutcrackers use a set of bearings, each a measure of the direction from the goal to a different landmark, when searching for that goal. The results of a simulation demonstrate that increasing the number of landmarks used results in increasingly precise searching. This …

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Search For A Hidden Goal By Clark's Nutcrackers (Nucifraga Columbiana) Is More Accurate Inside Than Outside A Landmark Array, Brett M. Gibson, Alan C. Kamil Jan 2001

Search For A Hidden Goal By Clark's Nutcrackers (Nucifraga Columbiana) Is More Accurate Inside Than Outside A Landmark Array, Brett M. Gibson, Alan C. Kamil

Papers in Behavior in Biological Sciences

In three experiments in which an open-room delayed response task was used, we explored how Clark's nutcrackers use landmarks to search for a hidden goal when multiple potential goal locations were present. In Experiment 1, nutcrackers presented with three spatial samples were able to use relative local cues from an array that changed positions throughout a session to return to a hidden goal during a test. In Experiment 2, the number of samples varied from one to three prior to the test. The nutcrackers performed as well with one sample as with two or three samples. In Experiment 3, we …

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The Use Of Relative And Absolute Bearings By Clark's Nutcrackers, Nucifraga Columbiana, Juli E. Jones, Alan C. Kamil Jan 2001

The Use Of Relative And Absolute Bearings By Clark's Nutcrackers, Nucifraga Columbiana, Juli E. Jones, Alan C. Kamil

Papers in Behavior in Biological Sciences

Two groups of Clark's nutcrackers were trained to find buried seeds whose location was defined by a constant angle from two landmarks whose interlandmark distance and position in the room varied across trials. The first group had a landmark array that was always placed in the same orientation with respect to the walls, allowing the animals to use both relative and absolute bearings. The second group had a landmark array that rotated across trials so that only relative bearings could be used to locate the seeds. The birds in each group learned the task and transferred to new interlandmark distances …

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Review Of Evolution And Cognition, Edited By Cecilia Heyes And Ludwig Huber., Alan Kamil Jan 2001

Review Of Evolution And Cognition, Edited By Cecilia Heyes And Ludwig Huber., Alan Kamil

Papers in Behavior in Biological Sciences

Heyes and Huber have edited a volume that surveys much of the current research into cognition in animals, reflecting the strengths and weaknesses of this field. The book is divided into five sections. In the first part, titled “Orientations,” four authors lay out their basic general views of the field. The first two chapters in this section are by the editors. First, Heyes makes the case for an approach to evolutionary psychology that she labels “in the round,” an approach that would encompass studies of human and nonhuman animals alike and include a broad range of contemporary evolutionary approaches. This …

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Linear-Nonequilibrium Thermodynamics Theory For Coupled Heat And Mass Transport, Yaşar Demirel, Stanley I. Sandler Jan 2001

Linear-Nonequilibrium Thermodynamics Theory For Coupled Heat And Mass Transport, Yaşar Demirel, Stanley I. Sandler

Yaşar Demirel Publications

Linear-nonequilibrium thermodynamics (LNET) has been used to express the entropy generation and dissipation functions representing the true forces and flows for heat and mass transport in a multicomponent fluid. These forces and flows are introduced into the phenomenological equations to formulate the coupling phenomenon between heat and mass flows. The degree of the coupling is also discussed. In the literature such coupling has been formulated incompletely and sometimes in a confusing manner. The reason for this is the lack of a proper combination of LNET theory with the phenomenological theory. The LNET theory involves identifying the conjugated flows and forces …

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The Wasp-Like Protein Scar Regulates Macropinocytosis, Phagocytosis And Endosomal Membrane Flow In Dictyostelium, David J. Seastone, Ed Harris, Lesly A. Temesvari, James E. Bear, Charles L. Saxe, James Cardelli Jan 2001

The Wasp-Like Protein Scar Regulates Macropinocytosis, Phagocytosis And Endosomal Membrane Flow In Dictyostelium, David J. Seastone, Ed Harris, Lesly A. Temesvari, James E. Bear, Charles L. Saxe, James Cardelli

Department of Biochemistry: Faculty Publications

Scar, a member of the WASp protein family, was discovered in Dictyostelium discoideum during a genetic screen for second-site mutations that suppressed a developmental defect. Disruption of the scar gene reduced the levels of cellular F-actin by 50%. To investigate the role of Scar in endocytosis, phagocytosis and endocytic membrane trafficking, processes that depend on actin polymerization, we have analyzed a Dictyostelium cell line that is genetically null for Scar. Rates of fluid phase macropinocytosis and phagocytosis are significantly reduced in the scar- cell-line. In addition, exocytosis of fluid phase is delayed in these cells and movement of fluid …

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Rab11-Like Gtpase Associates With And Regulates The Structure And Function Of The Contractile Vacuole System In Dictyostelium, Ed Harris, Kunito Yoshida, James Cardelli, John Bush Jan 2001

Rab11-Like Gtpase Associates With And Regulates The Structure And Function Of The Contractile Vacuole System In Dictyostelium, Ed Harris, Kunito Yoshida, James Cardelli, John Bush

Department of Biochemistry: Faculty Publications

Screening of a cDNA library revealed the existence of a Dictyostelium cDNA encoding a protein 80% identical at the amino acid level to mammalian Rab11. Subcellular fractionation and immunofluorescence studies revealed that DdRab11 was exclusively associated with the ATPase proton pump-rich contractile vacuole membrane system, consisting of a reticular network and bladder-like vacuoles. Video microscopy of cells expressing GFP-DdRab11 revealed that this Rab was associated with contractile vacuolar bladders undergoing formation, fusion and expulsion of water. The association of DdRab11 with contractile vacuole membranes was disrupted when cells were exposed to either hypo-osmotic conditions or an inhibitor of the ATPase …

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