Life Sciences Commons^™

Factors Associated With Occurrence And Density Of Wetland Birds In The Prairie Pothole Region Of Iowa, Steve E. Fairbairn, James J. Dinsmore

Journal of the Iowa Academy of Science: JIAS

Wetlands within wetland complexes in northwestern, north-central, and central Iowa were surveyed for bird use in 1997 and 1998. Species occurrence, species richness, and density of nesting species were related to wetland habitat variables. A habitat diversity index measuring the evenness of distribution of the different habitats within a wetland was the best predictor of species richness in both years. The habitat diversity index was also the best predictor of the occurrence of individual species in both 1997 and 1998. Eight of 11 species (7 3%) in 1997 and 13 of 18 species (72%) in 1998 had greater densities in …

Effects Of Hydroperiod On Metamorphosis In Rana Sphenocephala, Travis J. Ryan, Christopher T. Winne

Scholarship and Professional Work - LAS

Hydroperiod, the time a temporary pond holds water, is an important factor influencing recruitment in amphibian populations and structuring amphibian communities. We conducted an experiment to test the effect of hydroperiod on metamorphic traits of the southern leopard frog (Rana sphenocephala), a common amphibian in the southeastern United States. We reared larval R. sphenocephala in artificial ponds at a density of 32 larvae per tank (initial volume = approximately 650 liter). We dried the tanks according to natural patterns, using three different hydroperiods (60, 75 and 90 d). Experimental hydroperiods had a significant effect on the number of …

Livestock Production Costs Of Small Ranches On The Central Altiplano, Alfredo Benito Lopez

Theses and Dissertations

One of the more important economic activities in the Altiplano region is raising livestock, the exploitation of cattle, sheep, and llamas which are raised and adapted to the conditions surrounding this activity. Livestock production plays a fundamental role in the economy of farming families by providing them products such as meat, milk, cheese, fiber, skins, and other products that each translate into monetary revenues. The present study was carried out in the community of "Chama 6 de julio," Ingavi Province, Department of La Paz, about 83 km. (51.6 miles) outside of La Paz at an elevation of 3,792 m. (12,440 …

Zinc Fertilizer Rates And Mehlich Iii Soil Test Levels For Corn, Lloyd W. Murdock, Paula L. Howe

Agronomy Notes

Zinc (Zn) is the micronutrient most often deficient for corn in Kentucky. This problem occurs every year but is more commonly seen in years with a cool, wet spring. Although the environment, soil type and past erosion each have an effect, the most important factors controlling plant available Zn are the soil pH, extractable soil phosphorus (P) and extractable soil Zn. While the amount of Zn in the plant increases as the available soil Zn increases, increasing levels of soil P and pH are strongly associated with reduced levels of Zn in the plant.

Equatorial Inertia‐Gravity Waves Observed In Topex/Poseidon Sea Surface Heights, Sherryl Gilbert, Gary Mitchum

Marine Science Faculty Publications

We report an evaluation of the ability of the TOPEX/Poseidon altimeter to observe equatorial inertia‐gravity waves in the central Pacific. Aliasing problems limit us to examining meridional mode two, but this mode is an energetic one in the Pacific basin. These estimates of the temporal potential energy modulations are compared with estimates from tide gauges in the tropical Pacific, and we find that the time series obtained at these points show good agreement.

Appendix: Magnetic Experiments, M. Fuller, Y. Touchard, C. Endris, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

During Leg 189, magnetic experiments were continued in an attempt to understand and mitigate the troublesome magnetic overprints encountered in the paleomagnetism of recovered Ocean Drilling Program (ODP) sediment cores. Although these overprints do not interfere with magnetostratigraphy, except at low-latitude sites, they degrade some records sufficiently that the potentially invaluable reversal and secular variation records in the cores are not usable for high-resolution work. A nonmagnetic advanced hydraulic piston core (APC) barrel assembly was run on alternate APC cores throughout the leg, and the results from cores obtained with it were compared with those cored with the standard assembly. …

Site 1169, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

No abstract provided.

The Tasmanian Gateway: Cenozoic Climatic And Oceanographic Development, Neville F. Exon, James P. Kennett, Mitchell J. Malone, Henk Brinkhuis, George C.H. Chaproniere, Atsuhito Ennyu, Amelia E. Shevenell

Marine Science Faculty Publications

No abstract provided.

Leg 189 Summary, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

The Cenozoic Era is unusual in its development of major ice sheets. Progressive high-latitude cooling during the Cenozoic eventually formed major ice sheets, initially on Antarctica and later in the Northern Hemisphere. In the early 1970s, a hypothesis was proposed that climatic cooling and an Antarctic cryosphere developed as the Antarctic Circumpolar Current progressively thermally isolated the Antarctic continent. This current resulted from the opening of the Tasmanian Gateway south of Tasmania during the Paleogene and the Drake Passage during the earliest Neogene.

The five Leg 189 drill sites, in 2463 to 3568 m water depths, tested, refined, and extended …

Site 1170, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

No abstract provided.

Site 1171, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

No abstract provided.

Site 1172, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

No abstract provided.

Site 1168, Shipboard Scientific Party, Amelia E. Shevenell

Marine Science Faculty Publications

No abstract provided.

Nitric Oxide And Cnidarian-Dinoflagellate Symbioses: Pieces Of A Puzzle, Henry G. Trapido-Rosenthal, Katherine H. Sharp

Arts & Sciences Faculty Publications

The presence of nitric oxide synthase (NOS) activity is demonstrated in the tropical marine cnidarian Aiptasia pallida and in its symbiotic dinoflagellate algae, Symbiodinium bermudense. Enzyme activity was assayed by measuring the conversion of arginine to citrulline. Biochemical characterization of NOS from Aiptasia was characterized with respect to cellular localization, substrate and cofactor requirements, inhibitors, and kinetics. In response to acute temperature shock, anemones retracted their tentacles. Animals subjected to such stress had lower NOS activities than did controls. Treatment with NOS inhibitors caused tentacular retraction, while treatment with the NOS substrate L-arginine inhibited this response to stress, as did …

Activation Of Nf-Κb By Double-Stranded Rna (Dsrna) In The Absence Of Protein Kinase R And Rnase L Demonstrates The Existence Of Two Separate Dsrna-Triggered Antiviral Programs, Mihail S. Iordanov, John Wong, John C. Bell, Bruce E. Magun

CUP Faculty Research

Double-stranded RNA (dsRNA) of viral origin triggers two programs of the innate immunity in virus-infected cells. One is intended to decrease the rate of host cell protein synthesis and thus to prevent viral replication. This program is mediated by protein kinase R (PKR) and by RNase L and contributes, eventually, to the self-elimination of the infected cell via apoptosis. The second program is responsible for the production of antiviral (type I) interferons and other alarmone cytokines and serves the purpose of preparing naive cells for the viral invasion. This second program requires the survival of the infected cell and depends …

Vertical Transmission Of Kaposi's Sarcoma-Associated Herpesvirus, Hamakwa Mantina, Chipepo Kankasa, Winslow Klaskala, Brad Brayfield, James Campbell, Quijiang Du, Ganapati Bhat, Francis Kasolo, Charles Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Little is presently known about the specific routes of transmission of Kaposi’s sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain …

Managing N Inputs And The Effect On N Losses Following Excretion In Open-Dirt Feedlots In Nebraska, Galen Erickson, Terry Klopfenstein

Department of Animal Science: Faculty Publications

Feedlot nutrition will play an important role in meeting environmental challenges of beef cattle feedlots. Nutritionists are continually refining protein requirements and recently adopted a new, metabolizable protein (MP) system to more efficiently use N and allow more accurate diet formulation. Protein requirements vary by animal age and weight during the finishing period. Our hypothesis was that formulating diets with the MP system would decrease N inputs leading to decreased excretion and losses. Comparing industry average diets (13.5% CP) to phase-fed diets formulated to not exceed MP requirements decreased N inputs by 10 to 20% for calves and yearlings without …

Estimating Forage Protein Degradation In The Rumen, Terry J. Klopfenstein, R. A. Mass, K. W. Creighton, H. H. Patterson

Department of Animal Science: Faculty Publications

Forage proteins are degraded rapidly by rumen microorganisms and therefore supply relatively small quantities of undegraded intake protein (UIP). Growing cattle with high metabolizable protein requirements and lactating beef and dairy cows respond to UIP supplementation when fed high-forage diets, even though degradable intake protein (DIP) is adequate. This observation suggests that an accurate estimate of forage UIP is needed to establish optimal supplementation conditions. Microbial protein must be quantitated in duodenal or in situ residue samples to accurately measure forage UIP. Purines commonly are used as a microbial protein marker. Recent reports suggested that the original purine procedure generates …

Switching Feedlot Dietary Fiber Level For Cattle Fed In Winter, T. L. Mader, M. S. Davis, J. M. Dahlquist, A. M. Parkhurst

Department of Animal Science: Faculty Publications

Four feeding regimens were evaluated in two different outside facilities [tree windbreak provided (SP) vs no wind protection provided (NP)] over two winter seasons. Feeding regimens were 1) 7.5% (DM basis) alfalfa hay (AH) diet (Low- Low); 2) 15% (DM basis) AH diet switched to a 7.5% (DM basis) AH diet under cold stress conditions (High-Low); 3) 7.5% (DM basis) AH diet switched to a 15% (DM basis) AH diet under cold stress conditions (Low-High); and 4) 15% (DM basis) AH diet (High-High). For feeding regimens High-Low and Low- High, cold stress was determined by use of a model, based …

Origin And Conservation Genetics Of Threatened Ute Ladies’-Tresses, Spiranthes Diluvialis (Orchidaceae), Allen L. Szalanski, Gerry Steinauer, Richard Bischof, Jessica Lynn Petersen

Department of Animal Science: Faculty Publications

The Ute ladies’-tresses, Spiranthes diluvialis, is listed as a threatened orchid in west-central United States by the Federal government. Information on its origin and patterns of genetic variation is needed to develop effective conservation strategies for this species. DNA sequencing and polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) was used to evaluate genetic variation and structure of 23 populations of S. diluvialis. In addition, four congeneric species were analyzed to determine possible origins of the putative allotetraploid S. diluvialis. DNA sequencing and PCR-RFLP analysis of the nuclear ribosomal internal transcribed spacer (ITS) and mitochondrial and chloroplast DNA …

Utilization Of Bt Corn Hybrids In Growing Beef Steers, Jeffrey Folmer, Galen E. Erickson, D. J. Jordan, Todd Milton, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Two trials were completed to evaluate the efficacy of Bt corn hybrids for growing steers. After grain harvest, trial 1 used two fields of N7333 Bt and nonBt corn to evaluate grazing performance and preference of growing steers. Trial 2 compared early and late maturing varieties (N4242 and N7333, respectively) of Bt and nonBt corn hybrids in corn silage-based growing diets. No differences in performance or grazing preference were observed between N7333 Bt or nonBt residue. Steers fed corn silage from hybrids N4242 gained 11% faster (P>.01) and were 7% more efficient (P>.01) than those fed N7333 hybrids. …

Summer Grazing And Fall Grazing Pressure Effects On Protein Content And Digestibility Of Fall Range Diets, Trey Patterson, Terry J. Klopfenstein, Don C. Adams, Walter H. Schacht, Patrick E. Reece, Jacqueline A. Musgrave, Amy Herron

Nebraska Beef Cattle Reports

In 1997 and in 1998, four blocks of Sandhills range were used to examine summer grazing time and fall grazing pressure effects on fall diet quality. Three pastures within each block were grazed in June, July, or deferred from summer grazing each year. Multiple grazing pressures were created by grazing cows at various stocking rates in the fall. Diets were collected by esophageally fistulated cows. In 1997, diet protein and digestibility declined with increasing grazing pressure. In 1998, there were no effects of grazing pressure on fall diet protein or digestibility. July grazing reduced fall diet protein compared to June …

Candidate Gene Analysis For Loci Affecting Litter Size And Ovulation Rate In Swine, R. C. Linville, Daniel Pomp, R. K. Johnson, M. F. Rothschild

Department of Animal Science: Faculty Publications

A candidate gene approach was used to determine whether specific loci explain responses in ovulation rate (OR) and number of fully formed (FF), live (NBA), stillborn, and mummified pigs at birth observed in two lines selected for ovulation rate and litter size compared with a randomly selected control line. Line IOL was selected for an index of OR and embryonic survival for eight generations, followed by eight generations of two-stage selection for OR and litter size. Line C was selected at random for 16 generations. Line COL, derived from line C at Generation 8, underwent eight generations of two-stage selection. …

Nf01-451 Consumer Responsibility In Health Care: Improving Communication With Your Provider, Mary Ellen Rider, Paul Flack

University of Nebraska-Lincoln Extension: Historical Materials

The U.S. health care system continues to undergo reform. The direction of change places more emphasis on the patient to be a responsible partner in his/her own care and for those for whom they are responsible (family members) for care. One of the most important skills consumers have to exercise in this partnership is communication skills.

Nf01-452 Bacterial Blight On Geranium, Loren J. Giesler, Jay B. Fitzgerald

University of Nebraska-Lincoln Extension: Historical Materials

The focus of this Nebfact is to help producers diagnose suspected bacterial blight problems and appropriately manage the situation.

Nf01-462 Turf Disease Fact Sheet No. 2: Management Program For Dollar Spot, John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact is about turf disease and includes information about managing Dollar Spot.

Nf01-461 Turf Disease Fact Sheet No. 1: Management Program For Necrotic Ring Spot And Summer Patch, John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact is about turf disease and includes information about managing Necrotic Ring Spot and Summer Patch.

Nf01-469 Turf Disease Fact Sheet No. 9: Management Program For Pink And Gray Snow Molds, John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact is about turf diseases and includes information about managing pink and gray snow molds.

Nf01-467 Turf Disease Fact Sheet No. 7: Management Program For Anthracnose, John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact is about turf disease and includes information about managing anthracnose.

Nf01-465 Turf Disease Fact Sheet No. 5: Management Program For Pythium Blight, John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact is about turf disease and includes information on managing pythium blight.