Open Access. Powered by Scholars. Published by Universities.®

Agricultural Science Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Nebraska - Lincoln

Discipline
Keyword
Publication Year
Publication

Articles 2311 - 2340 of 2597

Full-Text Articles in Agricultural Science

Proceedings Of The 22nd Annual Meeting, Southern Soybean Disease Workers (February 20-22, 1995, St. Louis, Missouri), John Rupe, Brian M. Anderson, Robert P. Mulrooney, Gabe Sciumbato, Glenn G. Hammes Feb 1995

Proceedings Of The 22nd Annual Meeting, Southern Soybean Disease Workers (February 20-22, 1995, St. Louis, Missouri), John Rupe, Brian M. Anderson, Robert P. Mulrooney, Gabe Sciumbato, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

Business session

Soybean Disease Loss Estimate for the Southern United States during 1994. JA Wrather

Treasurer report. GG Hammes

SSDW Committee Chairmen for 1994-1995

Graduate student papers

Host preference of Rotylenchulus reniformis for weed species common to Louisiana soybean. CH Carter, EC McGawley, and JS Russin

Development of an immunoassay for Heterodera glycines eggs. MJ Kennedy, JE Schoelz, TL Niblack, PA Donald

Effects of delayed planting and host susceptibility on colonization of soybean by Calonectria crotalariae and development of red crown rot. PU Kuruppu, JS Russin, and EC McGawley

Effects of long-term corn/soybean rotation on pathogenicity of Pythium populations …


Intsormil Annual Report 1994, John M. Yohe, Joan Frederick, Dorothy Stoner Jan 1995

Intsormil Annual Report 1994, John M. Yohe, Joan Frederick, Dorothy Stoner

INTSORMIL Impacts and Bulletins

USAID conducted an overall evaluation of the Collaborative Research Support Programs (CRSPs), including lNTSORMIL, between May and July 1994. According to the "CRSP Evaluation Scope of Work" developed by USAID, the goal of this evaluation was to provide an objective assessment of the degree to which each of the CRSPs has had an impact on increasing agricultural production and development, and improving natural resource management through the development and dissemination of new and/or more appropriate sustainable agriculture technologies. The evaluation also assessed the extent to which the CRSP framework has responded to past Agency expectations and objectives and if the …


Local Action Of Trophoblast Interferons In Suppression Of The Development Of Oxytocin And Oestradiol Receptors In Ovine Endometrium, G. E. Lamming, D. C. Wathes, A. P. F. Flint, J. H. Payne, K. R. Stevenson, J. L. Vallet Jan 1995

Local Action Of Trophoblast Interferons In Suppression Of The Development Of Oxytocin And Oestradiol Receptors In Ovine Endometrium, G. E. Lamming, D. C. Wathes, A. P. F. Flint, J. H. Payne, K. R. Stevenson, J. L. Vallet

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Luteolysis in sheep is associated with uterine secretion of pulses of prostaglandin F(PGF) due to the action of luteal oxytocin on endometrial oxytocin receptors. For pregnancy to become established inhibition of oxytocin receptors is important as an antiluteolytic mechanism. The maternal recognition of pregnancy in cattle and sheep involves production, by the trophoblast, of a type 1 interferon (IFN-τ)that suppresses uterine development of oxytocin receptors and the generation of luteolytic episodes of PGF. The action of IFN-τ in surgically prepared unilaterally pregnant ewes was investigated. Finn-Dorset ewes were anaesthetized on day 6 or 7 …


Environmental Modification Of Hard Red Winter Wheat Flour Protein Composition, Robert A. Graybosch, C. J. Peterson, P. Stephen Baenziger, D. R. Shelton Jan 1995

Environmental Modification Of Hard Red Winter Wheat Flour Protein Composition, Robert A. Graybosch, C. J. Peterson, P. Stephen Baenziger, D. R. Shelton

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The intrinsic processing quality of wheat (Triticum aestivum L.) cultivars is modified significantly by cultural conditions and climate. In an attempt to understand the biochemical basis of such variation, environmental modification of flour protein content and composition was measured. Thirty hard red winter wheat cultivars and experimental lines were grown at 17 Nebraska environments during 1990 and 1991. Environmental conditions, including grain filling duration, temperature and relative humidity during grain filling, were monitored. Grain yield and test weight also were determined as environmental indicators. Significant linear correlations between flour protein content, as measured by near-infrared spectroscopy, were observed only …


An Automated Plot Harvest System For Use With A Commercial Forage Harvester, Jeffrey F. Pedersen, Kenneth J. Moore Jan 1995

An Automated Plot Harvest System For Use With A Commercial Forage Harvester, Jeffrey F. Pedersen, Kenneth J. Moore

Department of Agronomy and Horticulture: Faculty Publications

This automated harvest system is based on minimal modification of currently available commercial forage harvesters. Using 6.8 m plots separated by 0.75 m alleys, a single operator can harvest, finely chop, and collect wet plot weights of forage sorghum [Sorghum bicolor (L.) Moench] or pearl millet [Pennisetum glaucum (L.) R. Hr.] in <1 min per plot. Harvested material is deposited in a pile in the center of each plot. Subsamples for moisture and quality analysis can easily and safely be obtained from the pile.


Alternative Approaches To On-Farm Research And Technology Exchange, Charles A. Francis, Victoria Mundy, Rhonda Janke, James King Jan 1995

Alternative Approaches To On-Farm Research And Technology Exchange, Charles A. Francis, Victoria Mundy, Rhonda Janke, James King

CARI Extension and Education Materials for Sustainable Agriculture

Decision Case Studies are Ideal for On-Farm Research by R. Kent Crookston (University of Minnesota)

Use of On-Farm Research by Farmers for Technology Development and Transfer by Stewart Wuest, Baird Miller, Stephen Guy, Russ Karow, Rojer Veseth, and Donald Wysocki (Washington State University, University of Idaho, and Oregon State University)

Best Information for Choosing Crop Varieties by Dale Hicks and Robert Stucker (University of Minnesota)

Adaptability Analysis for Diverse Environments by Peter Hildebrand and John Russell (University of Florida and Washington State University)

Complementary Abilities and Objectives in On-Farm Research by Derrick Exner (Iowa State University)

Credibility of On-Farm Research …


Brown· Midrib Sorghum Silage For Midlactation Dairy Cows, R. J. Grant, S. G. Haddad, K. J. Moore, Jeffrey F. Pedersen Jan 1995

Brown· Midrib Sorghum Silage For Midlactation Dairy Cows, R. J. Grant, S. G. Haddad, K. J. Moore, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 ± 5 DIM were assigned to one of four diets in replicated 4 X 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 ± 20 DIM) were assigned to the same diets in a 3x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (OM basis). The DMl was greater for the corn and brown …


In Vitro Starch Disappearance Procedure Modifications, C. J. Richards, Jeffrey F. Pedersen, R. A. Britton, R. A. Stock, C. R. Krehbiel Jan 1995

In Vitro Starch Disappearance Procedure Modifications, C. J. Richards, Jeffrey F. Pedersen, R. A. Britton, R. A. Stock, C. R. Krehbiel

Department of Agronomy and Horticulture: Faculty Publications

Four in vitro experiments evaluated the effects of ruminal fluid inoculum:artificial saliva ratios,

grinder type, grind size, and diet of ruminal fluid donor on in vitro starch disappearance. Experiment 1 examined rates of starch disappearance and coefficients of determination obtained by linear regression of starch disappearance using five grain sorghum (Sorghum bicolur (L.) Moench) lines, a corn (Zeu muys L.) control, and a wheat (Triticum aestivum L.) control. Grains were incubated for 4, 8, 12, 16, and 20 h with inoculum varying in proportion of ruminal fluid and artificial saliva ( l:l, 1:2, 1:3, and 1:4). In …


Umingmakstrongylus Pallikuukensis Gen. Nov. Et Sp. Nov. (Nematoda: Protostrongylidae) From Muskoxen, Ovibos Moschafus, In The Central Canadian Arctic, With Comments On Biology And Biogeography, Eric P. Hoberg, Lydden Polley, A. Gunn, J. S. Nishi Jan 1995

Umingmakstrongylus Pallikuukensis Gen. Nov. Et Sp. Nov. (Nematoda: Protostrongylidae) From Muskoxen, Ovibos Moschafus, In The Central Canadian Arctic, With Comments On Biology And Biogeography, Eric P. Hoberg, Lydden Polley, A. Gunn, J. S. Nishi

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Umingmakstrongylus pallikuukensis gen. nov. et sp. nov. is established for a protostrongylid nematode in muskoxen, Ovibos moschatus, from the Kitikmeot Region (central Arctic) of the Northwest Territories, Canada. It is distinguished from Cystocaulus and other Muelleriinae by characters that include the following: males: deeply incised, bilobed bursa, independent externodorsal rays, telamon composed of distal transverse plate, absence of falcate crurae, and spicules not distally split; females: absence of provagina; and first-stage larvae: presence of three cuticular folds on the tail. The great length of females (468 mm) and males (171 mm) is exceptional among the Protostrongylidae. Pathognomonic lesions include …


Coordination Of Adsorbed Boron: A Ftir Spectroscopic Study, Chunming Su, Donald L. Suarez Jan 1995

Coordination Of Adsorbed Boron: A Ftir Spectroscopic Study, Chunming Su, Donald L. Suarez

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

We studied B adsorption on amorphous aluminum and iron hydroxides, allophane, and kaolinite as a function of pH and initial B concentration. Boron adsorption lowered the point of zero charge of all four adsorbents, implying specific adsorption (inner-sphere complexation) of B. We provided novel information on the coordination of B adsorbed at mineral-water interfaces by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The ATR-FTIR spectra of interfacial B species were influenced by pH and mineral type. Strong trigonal B and weak tetrahedral B bands of the asymmetric stretching mode were observed on the difference spectra at pH
  ≈7 for …


Endocrinology Of The Avian Reproductive System, Mary Ann Ottinger, Murray R. Bakst Jan 1995

Endocrinology Of The Avian Reproductive System, Mary Ann Ottinger, Murray R. Bakst

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The purpose of this review is to provide an overview of the avian reproductive system. Attention is given to the neuroendocrine regulation of hypothalamic and pituitary gland hormones as well as the target tissues regulated by these hormones. Emphasis is placed on the dynamics of the system and the effects of alterations resulting from environmental and other influences on the function of the reproductive system. The ovulatory cycle, oviduct, and shell gland are discussed relative to egg formation and the hormonal regulation of this process. Testicular function and the cellular bases for spermatogenesis and steroid production are also discussed.


Symposium On The Phyllochron: Importance Of The Phyllochron In Studying Development And Growth In Grasses, Wallace Wilhelm, Gregory S. Mcmaster Jan 1995

Symposium On The Phyllochron: Importance Of The Phyllochron In Studying Development And Growth In Grasses, Wallace Wilhelm, Gregory S. Mcmaster

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The phyllochron, which is defined as the interval between similar growth stages of successive leaves on the same culm, has been used extensively to describe and understand development of grasses. The purpose of this paper is to introduce seven papers presented as part of the symposium Understanding Development and Growth in Grasses: Role of the Phyllochron Concept. Environmental (temperature, water, and day length) factors and genetics affect the duration of the phyllochron. The following seven papers broaden the discussion of these topics and present new concepts about how the environment and genetics impact the relationship between leaf appearance and …


Genetic And Phenotypic (Co)Variances For Growth And Carcass Traits Of Purebred And Composite Populations Of Beef Cattle, K. E. Gregory, L. V. Cundiff, R. M. Koch Jan 1995

Genetic And Phenotypic (Co)Variances For Growth And Carcass Traits Of Purebred And Composite Populations Of Beef Cattle, K. E. Gregory, L. V. Cundiff, R. M. Koch

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Least squares means, genetic (σg), and phenotypic (σp) standard deviations, and phenotypic coefficients of variation (CV) were estimated on an age-constant basis for growth, carcass, and meat traits of castrate males from 12 breed groups combined, for 9 purebreds combined, and for the F3 generation of three composite populations combined to which the nine purebreds contributed. Also, heritabilities ( h2) and genetic ( rg) and phenotypic ( rp) correlations were estimated among growth, carcass, and meat traits for all breed groups combined involving 1,594 individuals that were the progeny of …


Effect Of Semen Storage On The Number Of Spermatozoa In The Perivitelline Layer Of Laid Turkey Eggs, A. M. Donoghue, M. R. Bakst, D. R. Holsberger, D. J. Donoghue Jan 1995

Effect Of Semen Storage On The Number Of Spermatozoa In The Perivitelline Layer Of Laid Turkey Eggs, A. M. Donoghue, M. R. Bakst, D. R. Holsberger, D. J. Donoghue

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A progressive decline in fertility over the course of egg production may be observed when turkey hens are inseminated weekly with semen stored for 24 h. In vitro storage of spermatozoa before insemination results in lower fertilization, possibly because fewer spermatozoa survive selection and storage in the hen's sperm storage tubules in vivo; alternatively, stored spermatozoa may be as capable of reaching the egg as are fresh spermatozoa, but unable to penetrate and fertilize the egg normally. The objective of this study was to determine whether this decline in fertility is a result of fewer spermatozoa reaching the egg …


Quantitative Mass Production Of Hydrotaea Aenescens (Diptera: Muscidae), Jerome Hogsette, Frank Washington Jan 1995

Quantitative Mass Production Of Hydrotaea Aenescens (Diptera: Muscidae), Jerome Hogsette, Frank Washington

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A covered oviposition device was developed that allows collection of large numbers of Hydrotaea aenescens (Wiedemann) (formerly Ophyra aenescens) eggs. Eggs can be measured and known numbers added to larval rearing medium so this beneficial fly can be reared quantitatively for the first time. With the use of quantitative rearing techniques and a new diet consisting of 5 parts Gainesville house fly diet and 1 part meat and bone meal, H. aenescens can be mass-reared easily for biological control studies.


Seed Physiology, Production & Technology, Wallace Wilhelm, B.E. Johnson, J. S. Schepers Jan 1995

Seed Physiology, Production & Technology, Wallace Wilhelm, B.E. Johnson, J. S. Schepers

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Detasseling is used in hybrid corn (Zea mays L.) seed production to ensure harvested seeds have the desired genetic complement. Both mechanical and hand detasseling result in loss of some leaf tissue and plant N. The objective of this study was to determine if seed yield and quality and N content of grain and stover were affected by leaf removal during detasseling. The treatments evaluated were removal of tassel only, tassel plus one leaf, tassel plus two leaves, tassel plus three leaves, tassel plus four leaves, and no tissue removed (control). The leaf area index (LAI) declined linearly, about …


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 Nov 1994

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. …


Irrigation And Culm Contribution To Yield And Yield Components Of Winter Wheat, Gregory S. Mcmaster, Wallace Wilhelm, Patricia N. S. Bartling Nov 1994

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 …


Imbibition Response Of Winter Wheat To Water-Filled Pore Space, Guillermo A. Studdert, Wallace Wilhelm, James F. Power Nov 1994

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 …


Proceedings Of The 21st Annual Meeting, Southern Soybean Disease Workers (March 6-8, 1994, Tulsa, Oklahoma), Glenn Bowers, John Rupe, Brian M. Anderson, Gabe Sciumbato, Glenn G. Hammes Mar 1994

Proceedings Of The 21st Annual Meeting, Southern Soybean Disease Workers (March 6-8, 1994, Tulsa, Oklahoma), Glenn Bowers, John Rupe, Brian M. Anderson, Gabe Sciumbato, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

1993-94 SSDW Committee Chairs

1993-94 SSDW Officers

Graduate student competition

Resistance of Soybean Cultivars in Maturity Group IV-VIII to Rotylenchulus reniformis. JJ Cornelius and GW Lawrence

Evaluation of Susceptibility of Soybean to Red Crown Rot caused by Calonectria crotalariae in the Field. KD Kim, JS Russin, and JP Snow

Contributed papers

Soybean Disease Loss Estimate for the Southern United States During 1993, Table 1. Estimated percent Joss of soybean yields in 1993 to disease, Table 2. Estimated reduction of soybean yields in 1993 to disease, and Table 3. Southern states soybean disease loss estimate total in bushels and …


Research And Extension Needs For Integrated Pest Management For Arthropods Of Veterinary Importance, Christopher J. Geden, Jerome Hogsette Jan 1994

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 Jan 1994

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 Jan 1994

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 …


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 Jan 1994

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 …


Purification Of The Major Soybean Leaf Acid Phosphatase That 1s Increased By Seed-Pod Removal, Paul E. Staswick, Chuck Papa, Jing-Feng Huang, Yoon Rhee Jan 1994

Purification Of The Major Soybean Leaf Acid Phosphatase That 1s Increased By Seed-Pod Removal, Paul E. Staswick, Chuck Papa, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Fruit removal for 5 weeks after flowering increased acid phosphatase activity 10-fold in soybean (Glycine max 1. Merr. vai Hobbit) leaves compared with normal seed-pod-bearing plants. The major acid phosphatase activity in leaves was purified over 2700-fold, yielding a single polypeptide of 51 kD with a specific activity of 1353 units/mg protein using p-nitrophenylphosphate as the substrate. lsoelectric focusing demonstrated that the purified protein co-migrated with a majority of the activity that increased in leaves following seed-pod removal. lmmunoblot analysis demonstrated that at least part of the increased activity was dueto an increased abundance of the phosphatase protein. In situ …


Cdna Sequence For The Ribulose 1,5 Bisphosphate Carboxylase/Oxygenase Complex Protein A Protein That Accumulates In Soybean Leaves In Response To Fruit Removal, Paul E. Staswick, Steven J. Crafts-Brandner Jan 1994

Cdna Sequence For The Ribulose 1,5 Bisphosphate Carboxylase/Oxygenase Complex Protein A Protein That Accumulates In Soybean Leaves In Response To Fruit Removal, Paul E. Staswick, Steven J. Crafts-Brandner

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max L.) transiently accumulates two abundant vegetative storage proteins, VSP A and VSP B, in vacuoles of above-ground vegetative tissues (Wittenbach, 1983; Staswick, 1990). As older leaves and stems become a source of exported metabolites for developing sinks, the VSPs are preferentially degraded and the resulting metabolites are presumably mobilized in the xylem and phloem stream. A striking feature of these proteins is that VSP gene expression is dramatically increased in mature leaves following the remova1 of reproductive sinks (seed pods) and the amount of these proteins increases accordingly (for review, see Staswick, 1994). Other changes …


Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist Jan 1994

Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Yield loss models have been developed and evaluated for irrigated rice ecosystems with respect to effects of Echinochloa crusgalli. Simple regression models that give the relation between yield loss and weed density or relative leaf area are discussed with respect to their practical value in weed management in rice. More complex eco-physiological process models have been developed and used for rice ecosystems as well. Such models can be useful as a tool in research, whereas more simple approaches are needed for practical application in weed management.


Two-Dimensional Transport Model For Variably Saturated Porous Meda With Major Ion Chemistry, Jiří Šimůnek, Donald L. Suarez Jan 1994

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 …


Fate Of Fluorescent Stained Sperm Following Insemination: New Light On Oviducal Sperm Transport And Storage In The Turkey, Murray R. Bakst Jan 1994

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 …


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 Jan 1994

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 …