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

Digital Commons Network™

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

Life Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 50071 - 50100 of 52497

Full-Text Articles in Entire DC Network

Housing And Management To Reduce Climactic Impacts On Livestock, G. Leroy Hahn Jan 1981

Housing And Management To Reduce Climactic Impacts On Livestock, G. Leroy Hahn

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

Weather is a constraint on efficient livestock production systems. Evaluation of the degree of constraint is a difficult, but necessary task before selection of appropriate modifications in management or environments can be made. The basis for rational selection from available alternatives for the limitation of climatic stress in livestock has continued to improve, particularly with the development of rudimentary functional relationships between animal performance and weather parameters. Such relationships, when combined with probabilistic knowledge of the weather parameters, permit prediction of the reduction in animal performance under natural conditions, or of the benefits to be derived from proposed housing or …


Transactions Of The Nebraska Academy Of Sciences And Affiliated Societies Volume Ix (1981): Table Of Contents Jan 1981

Transactions Of The Nebraska Academy Of Sciences And Affiliated Societies Volume Ix (1981): Table Of Contents

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Nebraska Academy of Sciences, Officers, Policy Committee .......... ii

Editorial Board, Instructions to Contributors .......... v

Membership Objectives and Friends of the Academy .......... vi

Anthropology

Preliminary report on the 1979 excavations at the Clary Ranch Site (Myers, Corner, and Tanner) .......... 1

Biological and Medical Sciences

Sister chromatid exchanges in a male with a Y /Y translocation (M. G. Butler) .......... 9

Further observations on polymegaly in species of the Drosophila affinis subgroup (Ho-Chi Chang and D. D. Miller) .......... 13

Pruduction rates of aquatic insects in a turbid reservoir (J. C. Lund and E. J. Peters) .......... 23 …


Production Rates Of Aquatic Insects In A Turbid Reservoir, John C. Lund, Edward J. Peters Jan 1981

Production Rates Of Aquatic Insects In A Turbid Reservoir, John C. Lund, Edward J. Peters

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Buckley Creek 3F is a turbid 13 ha reservoir in southeastern Nebraska. The quality of the environment was assessed in 1977 with an annual production estimate of the benthic insects.

Monthly bottom samples were taken using a 15 cm (6 in.) Ekman dredge. To observe any correlation between production and other factors, chemical and physical parameters consisting of total alkalinity, hardness, pH, conductivity, salinity, temperature, dissolved oxygen, and suspended solids were monitored.

Total benthis production was 0.156 g/m2/yr (dry weight). Individual genera produced between 0.001 (Chaoborus sp.) and 0.057 g/m2/yr (Hexagenia sp.). Published studies …


Barley Disease, Scald, Spot Type Net Blotch, Powdery Mildew, Leaf Diseases, Double Cropping, Resistance Of Cvt Barley, T N. Khan Jan 1981

Barley Disease, Scald, Spot Type Net Blotch, Powdery Mildew, Leaf Diseases, Double Cropping, Resistance Of Cvt Barley, T N. Khan

Experimental Summaries - Plant Research

I. Barley disease survey and an unidentified disorder on forrest barley. II. Scald: crop loss assessment – 81BA20, 81A17, 81MT23, 81WH30, 81A17, 81BA20, 81MT23, 81WH30, III. Scald: epidemics in simulated populations segregating for scald resistance – 81BA22, 81MT25, 81BA22, 81MT25. IV. Scald: reactions in single plant and hill plots – 81MT24, 81MT21, 81BA21, V. Spot type net blotch: crop loss assessment – 81C17. VI. Net blotch: effect of grazing on infection levels – 81A20. VII. Powdery mildew: crop loss assessment – 81PE5. VIII. Value of whole plot scores in assessing leaf diseases. IX. Disease and yield in simulated double cropping …


Doublegee Seed Dormancy. Lupins -Weed Control,Herbicides, New Products, D J. Gilbey Jan 1981

Doublegee Seed Dormancy. Lupins -Weed Control,Herbicides, New Products, D J. Gilbey

Experimental Summaries - Plant Research

Doublegee seed longevity x depth - 75WH66, 76C9, 76KA8. Grass control in dry sown lupins – 81A46, 81GE21, 81TS33. Broadleaf weed control in dry sown lupins – 81TS34, 81A47. Early post-emergence weed control – 81GE20. Early post-emergence weed control - lupins - 81TS32, 81A45. Post-emergence grass control in lupins. Post-emergence grass control in lupins None of the mixtures of Barban with Hoegrass and Matavin controlled the main target, Bromegrass. No significant differences due to treatments were detected in grain yields except at Avondale where annual ryegrass was the main grass weed which was controlled readily by the Hoegrass treatments as …


Long Term Rotation Trials., I Rowland. Jan 1981

Long Term Rotation Trials., I Rowland.

Experimental Summaries - Plant Research

Long term rotation trials. 66M29/2083EX, 67Cl3/2332EX , 67N4/2333EX, 68E5/2474EX , 68SG5/2475EX , 73SG16. Lupins: Wheat Rotation. 79GE36/3288EX, 79GE37/3288E, 80TS3/3288EX, 73SG16/3229EX Continuous Cropping with Nitrogenous Fertiliser. 80NA6


Legume Seed Inoculation, D. L. Chatel Jan 1981

Legume Seed Inoculation, D. L. Chatel

Experimental Summaries - Plant Research

Medic inoculation experiments – 81ME6, 81GE5. Inoculation trials were conducted at Holleton (81ME6) and Canna (81GE5).The major objectives were: 1. To test the field effectiveness of new strains of Rhizobium meliloti and to compare them with standard strains. 2. To initiate trials aimed at examining the performance of R. meliloti as long term colonisers of mildly acid soils. These trials are the first in a programme aimed at looking at the feasibility of developing acid tolerant strains for large areas of acid soil which are not suitable for growing subterranean clover. The 1981 trials will provide a basis for comparison …


Summary Of Results Of Field Experiments., M L. Poole, A R. Thompson Jan 1981

Summary Of Results Of Field Experiments., M L. Poole, A R. Thompson

Experimental Summaries - Plant Research

The aim of these experiments was to determine the relationship between bromegrass and ryegrass densities and their effects on wheat yields and in one case lupin yield 81 BA 45, Competition between bromegrass, ryegrass and wheat. 81 KA 28, Competition between bromegrass, ryegrass and wheat. 81 ME 35, Competition between bromegrass, ryegrass and wheat 81 TS 28, Competition between bromegrass, ryegrass and wheat. 81 WH 48, Competition between bromegrass, ryegrass and wheat. 81 NA 30, Competition between bromegrass, ryegrass and wheat. 81 MT 42, Abandoned due to severe waterlogging and disease. The wheat failed. The weeds grew magnificently. 81 MO …


Grass Control In Pastures., C W. Thorn Jan 1981

Grass Control In Pastures., C W. Thorn

Experimental Summaries - Plant Research

Crop Yields after Pasture Manipulation in 1980. Effect of Grass Control on Pasture Production. Effect of Grass Control on Animal Production. Pasture Density Effects and Composition on Soil Nitrogen. The Effect of Kerb (R) on Rapeseed, Linseed and Barley Grass. 80M041, 80M040, 80AB2, 81A23, 81 A188, 81Ba2, 81 N3, 81 N2, 81 A11 81N21, 81Ka1, 81Ka2, 81 Na3, 81NO5, 81MO1


Grain Legume Agronomy Programme, G Walton Jan 1981

Grain Legume Agronomy Programme, G Walton

Experimental Summaries - Plant Research

Lupin agronomy, series 1 - growth factor interactions. To evaluate the relative influence that various growth factors exert on crop yield. Lupin agronomy, series 2 - harvest index response to density. To establish whether the harvest index of the plants at maximum crop yield density remains constant over a range of environmental conditions and whether differences exist between cultivars. Lupin agronomy - nutrition. To compare the grain yield response to potash rates. Grain legumes for wheatbelt rotations. To compare the soil fertility after one year growth of different legume species. In the 1981 experiments, Derrimut field pea yielded well, outyielding …


The Distribution And Relative Abundance Of Aquatic Oligochaeta In The Upper Cache River System, Southern Illinois, In Relation To Water Quality, Mark Julian Wetzel Jan 1981

The Distribution And Relative Abundance Of Aquatic Oligochaeta In The Upper Cache River System, Southern Illinois, In Relation To Water Quality, Mark Julian Wetzel

Masters Theses

Species composition, distribution, abundance, and water quality relationships of aquatic oligochaetes occurring in the upper Cache River system, southern Illinois were investigated. Forty-two taxa of oligochaetes including 16 naidids, 22 tubificids and representatives of the families Aeolosomatidae, Branchiobdellidae, Enchytraeidae, and Lumbriculidae were collected. Four species of oligochaetes new to Illinois, Limnodrilus psammophilus Loden, L. rubripenis Loden, Psammoryctides (Spencerius) californianus Brinkhurst, and Haemonais waldvogeli Bretscher were collected during this study. Another species of Limnodrilus new to science is reported here, as yet undescribed. The thesis that aquatic oligochaetes can be used as true water quality indicator organisms is rejected. It is …


Three-Dimensional Home Range Of The Eastern Fox Squirrel, Sciurus Niger, Joi L. Augustin Jan 1981

Three-Dimensional Home Range Of The Eastern Fox Squirrel, Sciurus Niger, Joi L. Augustin

Masters Theses

Standard procedures for presenting home range data for species such as the fox squirrel on a single plane do not adequately represent the space they occupy. Comparisons of techniques for presenting the home range of this species on a three-dimensional basis were made using data obtained by direct observations of color marked squirrels. Three-dimensional ellipsoid models of their range varied from 9,154 m3 to 63,811 m3 and were assumed to be more accurate when observation points approached 50 in number. Rectangular parallelepipeds for the same data ranged from 9,784 m3 to 56,836 m3 and resulted in …


Thermodynamics Of Association And Catalysis Of N-Acyl-Peptidyl-Phenylalanine Amide Substrates By Chymotrypsin, John Paul Huff Jan 1981

Thermodynamics Of Association And Catalysis Of N-Acyl-Peptidyl-Phenylalanine Amide Substrates By Chymotrypsin, John Paul Huff

Dissertations

No abstract provided.


Microelectrophoretic Separation Of Isozymes In Relation To Aging In The Hydroids Campanularia Flexuosa And Cordylophora Lacustris, Patricia Marie Brown Jan 1981

Microelectrophoretic Separation Of Isozymes In Relation To Aging In The Hydroids Campanularia Flexuosa And Cordylophora Lacustris, Patricia Marie Brown

Master's Theses

No abstract provided.


Role Of Gulf Stream Frontal Eddies In Forming Phytoplankton Patches On The Outer Southeastern Shelf, James A. Yoder, Larry P. Atkinson, Thomas N. Lee, Hongsuk H. Kim, Charles R. Mcclain Jan 1981

Role Of Gulf Stream Frontal Eddies In Forming Phytoplankton Patches On The Outer Southeastern Shelf, James A. Yoder, Larry P. Atkinson, Thomas N. Lee, Hongsuk H. Kim, Charles R. Mcclain

CCPO Publications

Continuous surface mapping of temperature, salinity, and chlorophyll along a 300-km segment of the Gulf Stream cyclonic front defined the spatial scales of a large diatom patch that persisted throughout a 10-day study. The patch was localized in the upwelled cold core of a Gulf Stream frontal eddy centered over the 200-m isobaths off Jacksonville, Florida, in April 1979. The µ g liter-1 surface chlorophyll isopleth enclosed an area >1,000km2 with an alongshore dimension of 130km. Surface chlorophyll exceeded 5µg liter-1 within the upwelled cold core of the eddy, 10-100X higher than concentrations in Gulf Stream or …


Ecological And Genetic Separation Of Three Sympatric Species Of Aedes (Diptera: Culicidae) From The Kenya Coast, L. P. Lounibos, L. E. Munstermann Jan 1981

Ecological And Genetic Separation Of Three Sympatric Species Of Aedes (Diptera: Culicidae) From The Kenya Coast, L. P. Lounibos, L. E. Munstermann

All Peer-Reviewed Publications

Aedes ledgeri Huang, A. soleatus Edw. and A. calceatus Edw. of the group of A. aegypti (L.) of the subgenus Stegomyia collected on the coast of Kenya are distinguished on the strength of ecological and genetic (isozyme) data. The preferred oviposition sites of A. ledgeri and A. soleatus were tree holes above ground level, whereas A. calceatus favoured abandoned gastropod shells. A. ledgeri was most abundant in ecotonal habitats and A. soleatus in undisturbed forest At least two diagnostic enzyme loci separated each of the three species pairs. © 1981, Cambridge University Press. All rights reserved.


Iowa Academy Of Science Leadership Directory And Membership List, 1981-82, Iowa Academy Of Science Jan 1981

Iowa Academy Of Science Leadership Directory And Membership List, 1981-82, Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Board of Directors ... 2
Section Chairs ... 3
Section Vice Chairs ... 6
Committees ... 8
Past Presidents ... 22
Award Recipients ... 23
Membership Roster ... 27
Constitution, Article III ... 42


Protective Effects Of Certain Lythraceae Alkaloids And Homologs In Croton Oil- And Carrageenan-Induced Inflammation, John Alan Byrne Jan 1981

Protective Effects Of Certain Lythraceae Alkaloids And Homologs In Croton Oil- And Carrageenan-Induced Inflammation, John Alan Byrne

University of the Pacific Theses and Dissertations

Cryogenine's immunosuppressive activity was first evaluated by Kosersky, et al. (21) who, impressed by the drug's ability to inhibit both the irritant- and immune- mediated phases of adjuvant-induced polyarthritis (11), quantitatively confirmed this activity and clearly differentiated the action of cryogenine from that displayed by 6-mercaptopurine. A definitive study by Watson and Malone (22) confirmed cryogenine's lack of immunosuppressive capacity at effective anti-inflammatory dose levels.

The molecular complexity of the lythraceae alkaloids suggests that several active centers may account for their unique pharmacological profile. To assess these potentially active sites, two standard models of acute inflammation were selected for use …


Promotion Of Distant-Water Fishing Industry In Taiwan, Dah-Wen Shieh Jan 1981

Promotion Of Distant-Water Fishing Industry In Taiwan, Dah-Wen Shieh

Marine Affairs Theses and Major Papers

The growth of distant-water fishing industry in Taiwan has been steady during the period from 1965-1973. However, since 1973, the slow expansion of distant-water fisheries has been reflected in both the production side and the decreasing catch per unit effort. The increasing operation costs and the shrinking fishing grounds are mainly attributable to the limitation of distant-water fishing industry. The small scale of fishing companies with small-sized vessels also resulted in the inefficient operation in this highly competitive business. For Taiwan, distant-water fishing is not only a means of meeting general protein requirements for its population but also an important …


Back Matter Dec 1980

Back Matter

Henry Ford Hospital Medical Journal

No abstract provided.


Intensity Of The Second Heart Sound: Relation Of Physical, Physiological And Anatomic Factors To Auscultatory Evaluation, Paul D. Stein, Hani Sabbah Dec 1980

Intensity Of The Second Heart Sound: Relation Of Physical, Physiological And Anatomic Factors To Auscultatory Evaluation, Paul D. Stein, Hani Sabbah

Henry Ford Hospital Medical Journal

The intensity of the heart sound depends upon: 1) the distensibility of the aortic and pulmonary valves; 2) hemodynamic factors that cause the valves to distend and vibrate; 3) viscosity of the blood and its ability to inhibit diastolic valve motion; 4) the configuration of the aorta, pulmonary artery, and ventricle and the ability of the walls of the great vessels and ventricles to absorb or reflect sound energy; and 5) the capability of sound to be transmitted to the chest wall. Recognizing how these physical, physiological, and anatomic factors interact can help us to interpret auscultation of the intensity …


Bulletin 3929 - Irrigation In Western Australia, K S. Cole Dec 1980

Bulletin 3929 - Irrigation In Western Australia, K S. Cole

Bulletins - 3000 - 3999

Irrigation is essential in many parts of the world to produce essential food and profitable cash crops. Generally, those areas of land with less than 360 mm of rain spread over a distinct wet season of several months cannot grow crops for food or cash on rainfall alone. Then irrigation becomes necessary unless some peculiarity such as an oasis exists.


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …


Vegetative Community Descriptions For The North Platte River In Wyoming And Nebraska, Lynn Fisher Nov 1980

Vegetative Community Descriptions For The North Platte River In Wyoming And Nebraska, Lynn Fisher

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

A description of the vegetative communities in an area will provide an insight to wildlife potential and use of that area. Wildlife and its corresponding habitat are recognized as important for recreation and to the overall environmental quality of an area. The Water and Power Resources Service, Lower Missouri Region, is presently engaged in a study of the Platte River Basin, including an evaluation of wildlife habitat and associated environmental needs. Quantification of wildlife habitat along the South Platte River has been completed. Vegetation communities were described and habitat maps were prepared from color infrared aerial photographs (scale – 1:24,000). …


Conservation And Variation Of Nucleotide Sequences In Escherichia Coli Strains Isolated From Nature, Lawrence G. Harshman, Monica Riley Nov 1980

Conservation And Variation Of Nucleotide Sequences In Escherichia Coli Strains Isolated From Nature, Lawrence G. Harshman, Monica Riley

Lawrence G. Harshman Publications

A group of Escherichia coli isolates from nature were compared with one another and with laboratory strains of E. coli with respect to size distribution of chromosomal restriction endonuclease fragments and differences in nucleotide sequences in selected small portions of the genomes. The estimated frequency of base substitutions in nucleotide sequences in and near the trp operons of 26 of the 28 E. coli strains examined ranged from 0.008 to 0.066. Nucleotide sequences in or near λ prophage homologs were significantly more variable than the sequences in or near trp, tnaA, and thyA genes. Thus, the λ-homologous regions …


The Prairie Naturalist Volume 12, Numbers 3 And 4. September–December 1980 Oct 1980

The Prairie Naturalist Volume 12, Numbers 3 And 4. September–December 1980

The Prairie Naturalist

THE FLORA AND SANDHILLS PRAIRIE COMMUNITIES OF ARAPAHO PRAIRIE, ARTHUR COUNTY, NEBRASKA ▪ K. H. Keeler, A. T. Harrison and L. S. Vescio

USE OF ULTRASONIC SOUND TO ESTIMATE BODY FAT DEPOTS IN THE MALLARD ▪ G. A. Baldassarre, R. J. Whyte and E. G. Bolen

NORTHERN MOCKINGBIRD BREEDING IN NORTH DAKOTA ▪ D. Child, J. Fontaine, T. Gatz, M. Johnson and J. Oswald

SPRING ARRIVAL OF BIRDS AT WOODWORTH, NORTH DAKOTA ▪ K. F. Higgins, L. M. Kirsch, and J. M. Callow

HYBRIDIZATION AND TAXONOMIC STATUS OF GREATER PRAIRIE CHICKENS AND SHARP-TAILED GROUSE (HYBRIDIZATION IN GROUSE) ▪ D. W. …


Litter Production And Nutrient Content Of Litter In The Seasonally Flooded Dismal Swamp, Marta M. Gomez Oct 1980

Litter Production And Nutrient Content Of Litter In The Seasonally Flooded Dismal Swamp, Marta M. Gomez

Biological Sciences Theses & Dissertations

Litter production was studied in four plant communities in the Great Dismal Swamp, Virginia, that differ primarily in species composition and flooding regime. Greatest leaf deposition occurred in the more flooded communities, maple-gum (Acer-Nyssa) with 536 g m-2 yr-1 and cypress (Taxodium distichum (L.) Richard) with 528 g m-2 yr-1, followed by the cedar (Chamaecyparis thyoides (L.) BSP) and mixed hardwood (Quercus-Acer-Nyssa-Liquidambar) communities with 506 g m-2 yr-1 and 455 g m-2 yr-1, respectively. Litter nutrient concentrations were generally higher in the cypress and maple-gum stands, indicating greater nutrient availability …


The Beef Delivery System: Optimal Plant Sizes, Locations And Product Flows, J. C. Hafer, J. G. Kendrick Sep 1980

The Beef Delivery System: Optimal Plant Sizes, Locations And Product Flows, J. C. Hafer, J. G. Kendrick

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The United States beef delivery system is composed of three stages: procurement, processing, and distribution. Minimization of costs associated with these stages can be accomplished best by identification of optimal plant sizes and locations. Research was directed toward an analytical approach that could be used to minimize total costs of the U.S. beef delivery system. This report will discuss the grid system used to divide the · United States into study units, describe features of the model used, discuss research results, and offer conclusions.


Effect Of Fish Size On Prey Size Selection In Gambusia Affinis, Wayne A. Wurtsbaugh, Joseph J. Cech Jr., James Compton Sep 1980

Effect Of Fish Size On Prey Size Selection In Gambusia Affinis, Wayne A. Wurtsbaugh, Joseph J. Cech Jr., James Compton

Watershed Sciences Faculty Publications

Food size selection of the mosquitofish , Gambusia affinis affinis. was measured in aquaria using juvenile stages of the mosquito, Clllex tarsalb;, as prey. Fish size varied from recently born fry to large adult females. Food size selection was positively correlated with fish size. Mosquitofish fry (6-8 111m standard length) attacked and ate primarily first and second instar larvae. Fry attacked larger instars, but attack success on these was low (0 - 50%). Fish larger than 20 mm attached primarily pupae and third and fourth instar larva. No first instar mosquitoes were eaten. Attack success for these fish was above …


Mass Marking Of Mosquitofish: Preliminary Results, Bruce Vondracek, Wayne A. Wurtsbaugh, Joseph J. Cech Jr. Sep 1980

Mass Marking Of Mosquitofish: Preliminary Results, Bruce Vondracek, Wayne A. Wurtsbaugh, Joseph J. Cech Jr.

Watershed Sciences Faculty Publications

Three marking techniques were tested to determine their applicability for mosquitofish. Tetracycline drugs and DC Ar administered in the diet successfully marked laboratory-cultured mosquitofish, but exposure to direct sunlight in outdoor tanks resulted in the rapid disappearance of the marks. Preliminary data on fluorescent marks from a polystyrene pigment in a melamine-sulfonamide-formaldehyde resin forced into the dermal ,tissue with compressed air are more promising.

A t an optimal deliver pressure of 7.3 m Hg (140 p.s.i.) and spraying time of 15 sec., marking percentage is maximized and fish mortality is minimized. Mark retention time was up to 80 days in …