Open Access. Powered by Scholars. Published by Universities.®
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
- Discipline
Articles 1 - 13 of 13
Full-Text Articles in Life Sciences
Development Of Semi-Intensive Aquaculture Technologies In Honduras: Summary Of Freshwater Aquacultural Research Conducted From 1983-1992, Bartholomew Green, David Teichert-Coddington, Terrill Hanson
Development Of Semi-Intensive Aquaculture Technologies In Honduras: Summary Of Freshwater Aquacultural Research Conducted From 1983-1992, Bartholomew Green, David Teichert-Coddington, Terrill Hanson
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Aquacultural research has been conducted collaboratively in Honduras since 1983 by the International Center for Aquaculture and Aquatic Environments, Auburn University, and the Direccion General de Pesca y Acuicultura, Secretaria de Recursos Naturales. This research was carried out at the El Carao National Fish Culture Research Center, Comayagua, Honduras, under the auspices of the USAID-financed Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/A CRSP). The goal of the PD/A CRSP is to increase tilapia yields by optimizing resource use in systems based predominantly on natural pond productivity.
Irrigation And Culm Contribution To Yield And Yield Components Of Winter Wheat, Gregory S. Mcmaster, Wallace Wilhelm, Patricia N. S. Bartling
Irrigation And Culm Contribution To Yield And Yield Components Of Winter Wheat, Gregory S. Mcmaster, Wallace Wilhelm, Patricia N. S. Bartling
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Water is generally the limiting factor in U.S. Great Plains wheat (Triticum aestivum L.) production. With increasing demands for limited water, improving the efficacy of irrigation is critical. One technique is to irrigate during responsive stages of crop development, but few studies have examined this approach. This 2-yr study on a Nunn clay loam soil (fine, montmorillonitic, mesic Aridic Argiustoll) was designed to examine the effects of irrigation, based on stage of crop development, on winter wheat yield, yield components (on a plant basis), and specific culm responses. In the first year, the treatments were control (dryland), and irrigation …
Age-Related Resistance To 987p Fimbria-Mediated Colonization Correlates With Specific Glycolipid Receptors In Intestinal Mucus In Swine, Evelyn A. Dean-Nystrom, James E. Samuel
Age-Related Resistance To 987p Fimbria-Mediated Colonization Correlates With Specific Glycolipid Receptors In Intestinal Mucus In Swine, Evelyn A. Dean-Nystrom, James E. Samuel
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Strains of enterotoxigenic Escherichia coli that produce 987P fimbriae (987P+ strains) colonize the small intestines and cause diarrhea in neonatal (<6-day-old) pigs but not in weaned pigs. However, 987P+ E. coli strains adhere in vitro to intestinal epithelial cells from pigs of both ages. Two intestinal components, designated 987R and 987M, bind 987P fimbriae (987P) on Western blots (immunoblots). We examined brush borders (BB) and intestinal washes (IW) from pigs to determine if they contain glycolipids which bind 987P. Total glycolipid extracts from BB and IW of 4-week-old pigs were separated on thin-layer chromatograms and overlaid with purified 987P. Bound 987P were detected with 987P-specific antiserum. …
Imbibition Response Of Winter Wheat To Water-Filled Pore Space, Guillermo A. Studdert, Wallace Wilhelm, James F. Power
Imbibition Response Of Winter Wheat To Water-Filled Pore Space, Guillermo A. Studdert, Wallace Wilhelm, James F. Power
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Reduced temperature and increased bulk density associated with conservation tillage systems cause lower seed germination, seedling emergence, and early growth rates resulting in reduced plant stands. Prediction of the influence of soil condition on seed imbibition through simple soil measurements would help make agronomic decisions such as planting date and/or density. Our objectives were to evaluate the influence of soil water-filled pore space on winter wheat (Triticum aestivum L.) seed imbibition and to assess the possibility of describing the relationship through simple mathematical models. We measured the rate of water uptake by heat-killed wheat seeds at three levels of …
Fate Of Fluorescent Stained Sperm Following Insemination: New Light On Oviducal Sperm Transport And Storage In The Turkey, Murray R. Bakst
Fate Of Fluorescent Stained Sperm Following Insemination: New Light On Oviducal Sperm Transport And Storage In The Turkey, Murray R. Bakst
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
A novel approach was used to evaluate the distribution of sperm in the oviduct of turkey hens inseminated before or after the onset of egg production. Prior to insemination, sperm were stained with the nuclear fluorescent stain bisbenzimide. Sperm distribution in the sperm storage tubules (SST) of the uterovaginal junction and the infundibular tubular glands was determined by use of simultaneous differential interference contrast and fluorescence microscopy. In hens inseminated and examined prior to the onset of egg production, 94% of the SST contained sperm (21% were filled). In contrast, in hens inseminated initially before the onset of egg …
Comparative Germination Of Smooth Brome And Plains Rough Fescue, Perry L. Grilz, James T. Romo, James A. Young
Comparative Germination Of Smooth Brome And Plains Rough Fescue, Perry L. Grilz, James T. Romo, James A. Young
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Smooth brome (Bromus inermis Leyss.) is an aggressive invader of fescue prairie; however, little information is available on the germination ecology of this exotic perennial relative to native flora. This information is needed to understand the processes of invasion and to develop strategies to curb the spread of smooth brome. Germination of smooth brome and plains rough fescue (Festuca altaica subsp. hallii (Vasey) Harms) seeds was compared under various temperature regimes, levels of water stress, and light. Germination of both species was severely restricted by water stress, but not by temperatures between 5 and 25°C. Smooth brome had …
Repellency Of Aqueous Solutions Of Boric Acid And Polybor 3 To House Flies (Diptera: Muscidae), Jerome Hogsette, Philip Koehler
Repellency Of Aqueous Solutions Of Boric Acid And Polybor 3 To House Flies (Diptera: Muscidae), Jerome Hogsette, Philip Koehler
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Mixed-sex 3- to Sod-old adult house flies, Musca domestica (L.), were exposed in nonchoice, choice, and consumption tests to increasing levels of boric acid and polybor formulated in 10% sucrose to test for repellent effects. Results of nonchoice and choice tests suggested repellency to high levels of both borates. Consumption decreased at levels >2.25% boric acid and 3.0% polybor, with approximate intake of 0.102 and 0.161 mg of boron, respectively. Our results indicate that 2.25% boric acid and 3.0% polybor are optimal treatment levels.
Research And Extension Needs For Integrated Pest Management For Arthropods Of Veterinary Importance, Christopher J. Geden, Jerome Hogsette
Research And Extension Needs For Integrated Pest Management For Arthropods Of Veterinary Importance, Christopher J. Geden, Jerome Hogsette
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
In April, 1994, a workshop was held in Lincoln, Nebraska, to update the IPM document that resulted from a similar workshop in Manhattan, Kansas, in 1979 (Anonymous 1979). The workshop was initiated by Dr. Ralph A. Bram, USDA National Program Leader, and organized by Drs. Gustav D. Thomas, USDA-ARS, Lincoln, and John B. Campbell, University of Nebraska, North Platte. Participants were charged with assessing the current status of IPM programs for pests of veterinary importance, identifying needs for program improvements, and recommending future research and extension priorities. Participants, invited from federal and state government research and extension organizations, and the …
Response Of Leafy Spurge To Date Of Burning, Robert A. Masters
Response Of Leafy Spurge To Date Of Burning, Robert A. Masters
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The research was conducted on remnant tallgrass prairie located in Lancaster County, Nebraska in 1990. Plots (5 by 10-m) were not burned or burned on either April 23, May 2, May 14, or May 26, 1990. Leafy spurge stem density and yield and yield of associated herbaceous vegetation were determined in July 1990 to assess response of the grassland community to prescribed burning treatments. Burning in late April through mid-May stimulated leafy spurge stem production. Density of leafy spurge stems in plots burned by mid-May significantly exceeded (P<0.04) the stem density in plots burned at the end of May. Leafy spurge stem density in plots burned the first week in May averaged 84 stems m-2 as compared to only 27 stems m-2 in plots burned …
Colony Isolation And Secondary Culture Of Fetal Porcine Hepatocytes On Sto Feeder Cells, Neil C. Talbot, Vernon G. Pursel, Caird E. Rexroad Jr., Thomas J. Caperna, Anne M. Powell, Roger T. Stone
Colony Isolation And Secondary Culture Of Fetal Porcine Hepatocytes On Sto Feeder Cells, Neil C. Talbot, Vernon G. Pursel, Caird E. Rexroad Jr., Thomas J. Caperna, Anne M. Powell, Roger T. Stone
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The secondary culture of non-transformed parenchymal hepatocytes has not been possible. STO feeder cell-dependent secondary cultures of fetal pig hepatocytes were established by colony isolation from primary cultures of 26-d fetal livers. The liver cells had the typical polygonal morphology of parenchymal hepatocytes. They also spontaneously differentiated to form small biliary canaliculi between individual cells or progressed further to large multicellular duct-like structures or cells undergoing gross lipid accumulation and secretion. The secondary hepatocyte cultures expressed alpha-fetoprotein (AFP), albumin, and β-fibrinogen mRNA, and conditioned medium from the cells contained elevated levels of transferrin and albumin. STO feeder cell co-culture may …
A Continuous Culture Of Pluripotent Fetal Hepatocytes Derived From The 8-Day Epiblast Of The Pig, Neil C. Talbot, Caird E. Rexroad Jr., Anne M. Powell, Vernon G. Pursel, Thomas J. Caperna, Sherry L. Ogg, Neil D. Nel
A Continuous Culture Of Pluripotent Fetal Hepatocytes Derived From The 8-Day Epiblast Of The Pig, Neil C. Talbot, Caird E. Rexroad Jr., Anne M. Powell, Vernon G. Pursel, Thomas J. Caperna, Sherry L. Ogg, Neil D. Nel
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Continuous cultures of pluripotent prenchymal hepatocytes were derived from the epiblasts of 8-day-old pig blastocytes. The cells were polygonal and had phase-contrast dark, granular cytoplasm with prominent nuclei and nucleoli. These feeder-dependent cell cultures differentiated into large, multicellular, secretory, duct-like structures or formed small canaliculi between individual cells. Alternatively, the cells accumulated droplets that stained intensely with Oil Red O, a lipid-specific stain. Alpha-fetoprotein (AFP), albumin, and β-fibrinogen mRNAs were expressed as the cells differentiated in culture. Serum-free medium that was conditioned by the cells contained transferrin, AFP, and albumin. The growth and viability of the cells were inhibited by …
Effect Of The Conceptus And Lack Of Effect Of Uterine Space On Endometrial Protein Secretion During Mid-Gestation In Swine, Jeffrey Vallet, Harold Klemcke, Ronald Christenson
Effect Of The Conceptus And Lack Of Effect Of Uterine Space On Endometrial Protein Secretion During Mid-Gestation In Swine, Jeffrey Vallet, Harold Klemcke, Ronald Christenson
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The effect of the conceptus and of reduced uterine space on endometrial protein secretion was examined on Days 40, 60, and 80 of gestation in white crossbred gilts. Twenty-nine gilts were checked daily for estrus, and 15 were given 5 mg estradiol valerate daily from Days 11 to 15 (Day 0 = day of estrus) of the estrous cycle to induce pseudopregnancy. The remaining 14 pigs were mated during estrus. All pigs were laparotomized on Day 4, and one uterine horn was ligated to produce one crowded and one roomy uterine environment. Pigs were killed on Days 40, 60, and …
Two-Dimensional Transport Model For Variably Saturated Porous Meda With Major Ion Chemistry, Jiří Šimůnek, Donald L. Suarez
Two-Dimensional Transport Model For Variably Saturated Porous Meda With Major Ion Chemistry, Jiří Šimůnek, Donald L. Suarez
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
We present the development and demonstrate the use of the two-dimensional finite element code UNSATCHEM-2D for modeling major ion equilibrium and kinetic nonequilibrium chemistry in variably saturated porous media. The model is intended for prediction of major ion chemistry and water and solute fluxes for soils under transient conditions. Since the solution chemistry in the unsaturated zone is significantly influenced by variations in water content, temperature, and CO2 concentrations in the soil gas, all these variables are also calculated by the model. The major variables of the chemical system are Ca, Mg, Na, K, SO4, Cl, NO …