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1986

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Articles 1 - 30 of 1572

Full-Text Articles in Life Sciences

Winter Moon Over Cotton Field Dec 1986

Winter Moon Over Cotton Field

Farming in Arkansas

Image of a full moon over an old church and a cotton field during winter.


Plowed Field And Abandoned House Dec 1986

Plowed Field And Abandoned House

Farming in Arkansas

Image of a field that's been prepared for planting cotton with an abandoned farm house and collapsed building in the background.


Colloidal Gold Labelling Of Fibrinogen Receptors In Epinephrine – And Adp–Activated Platelet Suspensions, J. A. Oliver, R. M. Albrecht Dec 1986

Colloidal Gold Labelling Of Fibrinogen Receptors In Epinephrine – And Adp–Activated Platelet Suspensions, J. A. Oliver, R. M. Albrecht

Scanning Microscopy

It has been generally accepted for over twenty years that epinephrine stimulates platelet aggregation without inducing shape change. However, it has been recently reported that discoid platelets are not recruited into ADP-or epinephrine-stimulated aggregates. Previous work in our laboratory has suggested that platelet shape change is necessary for the binding of fibrinogen to its surface receptor, which is a prerequisite for platelet aggregation. These studies seem to indicate that epinephrine-induced platelet aggregation does involve shape change. To investigate this possibility, the extent of shape change and fibrinogen binding in suspensions of epinephrine-and ADP-activated and control platelets was assessed by scanning ...


Light And Electron Microscopic Localization Of Glycoconjugates With Gold-Labeled Reagents, J. Roth Dec 1986

Light And Electron Microscopic Localization Of Glycoconjugates With Gold-Labeled Reagents, J. Roth

Scanning Microscopy

This paper gives an overview of the use of lectins, glycoproteins, monoclonal anticarbohydrate antibodies, toxins, and glycosyltransferases for the detection and localization of cellular glycoconjugates in sections from embedded tissues by light and electron microscopy. In all these techniques particles of colloidal gold were used as a marker. For light microscopic studies routine conditions of embedding such as paraffin or Epon embedding could be employed. For electron microscopic studies the low temperature embedding technique using Lowicryl K4M was found to be the method of choice for the localization of sugar residues in intracellular compartments, the extracellular matrix and the plasma ...


Scanning Electron Microscopy Study Of Particles Generated By Laser Damage Of Aluminum Surfaces, L. L. Levenson, S. D. Traynor, G. A. Brost, F. Ziembo Dec 1986

Scanning Electron Microscopy Study Of Particles Generated By Laser Damage Of Aluminum Surfaces, L. L. Levenson, S. D. Traynor, G. A. Brost, F. Ziembo

Scanning Microscopy

A high intensity iodine laser (1.315 μm wavelength) was used to study laser-surface damage in vacuum. A 22mm diameter laser beam containing 3.9 J of energy was focused to a 1 mm spot on an aluminum plate mounted in a vacuum chamber. The laser pulse width was 7 μs (FWHM). A copper strip mounted on a quarter circle plate 3.5 cm from the laser spot was used to collect particles ejected from the surface. A scanning electron microscope (SEM) was used to measure the size and spatial distribution of the particles collected on the copper strip. It ...


The Scanning Electron Microscopy/Replica Technique And Recent Applications To The Study Of Fossil Bone, Timothy G. Bromage Dec 1986

The Scanning Electron Microscopy/Replica Technique And Recent Applications To The Study Of Fossil Bone, Timothy G. Bromage

Scanning Microscopy

The SEM/replica technique employs high resolution replica materials in order to reflect microstructural details of specimens, such as fossil bones, which cannot be observed directly. The described technique is simple, provides excellent resolution, is maximally adaptable to field and laboratory settings, and is applicable to large and topographically complex bone surfaces. The advent of the technique has made it largely possible to address certain issues in anthropology and paleontology. These contributions have principally been concerned with taphonomy as the study of the bone damage process, and bone biology as it relates to bone growth remodeling processes characterizing the facial ...


Scanning Electron Microscopy Of Early Dinosaur Egg Shell Structure: A Comparison With Other Rigid Sauropsid Eggs, Frederick E. Grine, James W. Kitching Dec 1986

Scanning Electron Microscopy Of Early Dinosaur Egg Shell Structure: A Comparison With Other Rigid Sauropsid Eggs, Frederick E. Grine, James W. Kitching

Scanning Microscopy

Fossil eggs attributable to dinosaur (probably prosauropod) parentage that have been recovered from the early Jurassic Elliot Formation sediments at the Rooidraai locality possess shells that are similar to those of birds and crocodilians, and distinctly unlike those of chelonians and gekkonids. The preserved shell is very thin, and distinct mammillary processes are lacking, although the inner surface displays an undulating contour. The absence of these processes may be attributable to the inner portion of the shell having been at least partially decalcified during incubation and not preserved in the fossil state. The shells appear to be composed of broadly ...


Quantitative Analysis Of Occlusal Microwear In Australopithecus And Paranthropus, Frederick E. Grine Dec 1986

Quantitative Analysis Of Occlusal Microwear In Australopithecus And Paranthropus, Frederick E. Grine

Scanning Microscopy

Quantitative analysis of microwear features preserved on the occlusal surfaces of the M2s of southern African specimens of Australopithecus and Paranthropus (the so-called 'gracile' and 'robust' australopithecines) reveals that there is no striking relationship in either taxon between occlusal facet inclination and the incidence of wear features. Within each taxon, Phase I and Phase II facets tend to differ in a similar manner in the total number of wear features, the percentage frequency of pitting, and in the orientation of wear scratches. Nevertheless, Paranthropus molars tend to display significantly greater numbers of microwear features on both Phase I ...


Analysis Of Primate Dental Microwear Using Image Processing Techniques, Richard F. Kay Dec 1986

Analysis Of Primate Dental Microwear Using Image Processing Techniques, Richard F. Kay

Scanning Microscopy

This paper introduces Fourier transformation as a rapid, replicable means for characterizing and distinguishing patterns of microscopic wear on primate teeth. The two-dimensional power spectra obtained from numerical Fourier transformation are shown to be different between two test patterns, one of which is composed of linear features and the other of randomly-spaced dots. A comparison is made, using Fourier transformation, of dental microwear patterns of small samples of two primate species, Ateles geoffroyi, the spider monkey, and Chiropotes satanas, the bearded saki. Ateles, with a scratch-dominated pattern of microwear, has a Fourier transform resembling that of the linear test pattern ...


Morphological Characterization Of Materials Using Low Voltage Scanning Electron Microscopy (Lvsem), Jesse Hefter Dec 1986

Morphological Characterization Of Materials Using Low Voltage Scanning Electron Microscopy (Lvsem), Jesse Hefter

Scanning Microscopy

The use of lower energy (0.5 to 10 keV) electron beams in the scanning electron microscope (LVSEM) provides a number of advantages in the imaging of materials, including increased topographic contrast and reduced specimen charging. Application of LVSEM to materials analysis was difficult in the past due to a number of instrumental difficulties, including low gun brightness, the increased effect of chromatic aberration upon lower energy beams, and the increased sensitivity of such electron beams to stray fields. Improvements in design have led to commercial instruments which provide the microscopist with the capability to analyze materials in this low-energy ...


Northeast Research Station Watertown, South Dakota Annual Progress Report, 1986, Agricultural Experiment Station, Plant Science Department Dec 1986

Northeast Research Station Watertown, South Dakota Annual Progress Report, 1986, Agricultural Experiment Station, Plant Science Department

Agricultural Experiment Station and Research Farm Annual Reports

This is the 1986 annual progress report for the Northeast Research Station in Watertown, South Dakota. This report is issued by the South Dakota Agricultural Experiment Station and the South Dakota State University Plant Science Department. This report includes information on the 1986 crop season, climate data applications of chloride for wheat, spring wheat breeding, oats research, barley and rye testing, grain trials, corn breeding row spacing, sunflower studies and trials, and weed control.


Endangered And Threatened Wildlife And Plants; Proposal To Determine The Black-Capped Vireo To Be An Endangered Species Dec 1986

Endangered And Threatened Wildlife And Plants; Proposal To Determine The Black-Capped Vireo To Be An Endangered Species

Endangered Species Bulletins and Technical Reports (USFWS)

The Service proposes to list the black-capped vireo (Vireo atricapillus) as an endangered species under provisions of the Endangered Species Act of I973 as amended. This small bird formerly bred from Kansas through Oklahoma and Texas to central Coahuila in Mexico. The vireo population is declining. It no longer occurs in Kansas, is gravely endangered in Oklahoma where it was found in only three small areas in 1986, and is no longer found in several parts of its former range in Texas. The black-capped vireo is threatened by brown beaded cowbird (Molothrus ater) nest parasitism and by loss of habitat ...


Revised Checklist Of North American Mammals North Of Mexico, 1986, J. Knox Jones Jr., Dilford C. Carter, Hugh H. Genoways, Robert S. Hoffmann, Dale W. Rice, Clyde Jones Dec 1986

Revised Checklist Of North American Mammals North Of Mexico, 1986, J. Knox Jones Jr., Dilford C. Carter, Hugh H. Genoways, Robert S. Hoffmann, Dale W. Rice, Clyde Jones

Mammalogy Papers: University of Nebraska State Museum

As in previous lists, orders, families, and genera are listed in conventional phylogenetic sequence mostly following Hall (1981) but, in a departure from previous lists, species are entered alphabetically within each genus. This will facilitate use of the checklist by those unfamiliar with intrageneric taxonomy. Some assemblages are not well enough understood to create a meaningful hierarchy at the specific level.


Scanning Electron Microscope Evaluation Of Drilling Damage And Acid Treatment Using Uncoated Core, D. R. Rothbard, R. A. Skopec, C. J. Bajsarowicz, T. H. Fate Dec 1986

Scanning Electron Microscope Evaluation Of Drilling Damage And Acid Treatment Using Uncoated Core, D. R. Rothbard, R. A. Skopec, C. J. Bajsarowicz, T. H. Fate

Scanning Microscopy

A novel SEM technique allows the observation of the same pore on a core face after each step in a series of dynamic flow tests. It requires no conductive coating and facilitates core flow using a one inch (25.4 mm) diameter plug. Three separate studies were undertaken in which the procedure was used to observe the effects of drilling mud invasion, waterflooding, and matrix acidization on individual grains and pores. In the drilling mud study it was found that 2% HF removed most of the siderite weighted mud, but that mud residue and etching of the framework grains resulted ...


Scanning Electron Microscopy Of Dentin Caries. Experimental In Vitro Studies With Streptococcus Mutans, Patrick A. Adriaens, Geert W. Claeys, Jan A. De Boever Dec 1986

Scanning Electron Microscopy Of Dentin Caries. Experimental In Vitro Studies With Streptococcus Mutans, Patrick A. Adriaens, Geert W. Claeys, Jan A. De Boever

Scanning Microscopy

This study was performed to gain better insight into the mechanisms involved in carious destruction of human dentin by Streptococcus mutans. In particular, bacterial colonization of dentin surfaces and bacterial invasion in dentin were studied.

Streptococcus mutans (S. mutans), strain NCTC 10449, was grown on sterile dentin blocks in a 10% CO2 atmosphere at 37°C. After 72, 120, 144 and 288 h of incubation the specimens were processed for scanning electron microscopic examination. The colonization of the dentinal surface progressed slowly and was nearly complete after 288 h. Invasion of S. mutans into the dentinal tubules was found ...


Replication Technique For Studying Microstructure In Fossil Enamel, A. D. Beynon Dec 1986

Replication Technique For Studying Microstructure In Fossil Enamel, A. D. Beynon

Scanning Microscopy

The present paper describes a two stage impression technique using a silicone elastomer suitable for field replication studies; which requires high dimensional stability, defined resolution, and being capable of reproducing inaccessible details. A test object consisting of etched pearlite possessed fine detail [>1μm to <0.1μm] which was suitable for testing negative/ positive replica combinations. Coltene President light-body impression material was capable of resolving parallel side depressions of widths ≧0.2μm, and it possesses very good dimensional stability with time, allowing the production of positive casts to be deferred for several months. Low viscosity Spurr resin reproduced this detail, and flowed into inaccessible sites.

Although there was evidence of bulk contraction on curing, there was no significant shrinkage on flat [linear] surfaces or in vertical relief dimensions.

Replicas of fractured hominid teeth showed good surface detail, and reproduction of inaccessible three-dimensional features on enamel surfaces. Enamel prism shape was pattern 3.


A Preliminary Study Of The Role Of Gastrointestinal Endocrine Cells In The Maintenance Of Villous Structure Following X-Irradiation, M. G. Wyatt, S. P. Hume, K. E. Carr, J. C. L. Marigold Dec 1986

A Preliminary Study Of The Role Of Gastrointestinal Endocrine Cells In The Maintenance Of Villous Structure Following X-Irradiation, M. G. Wyatt, S. P. Hume, K. E. Carr, J. C. L. Marigold

Scanning Microscopy

The mechanism of gastrointestinal villous damage following ionizing irradiation is complex. Various compartments within the gastrointestinal tract have in turn been considered important for the maintenance of normal villous structure. To date, however, evidence for a single overriding regulator of epithelial well-being is lacking.

In this study, the role of the gastrointestinal (enteroendocrine) cells is explored and comparison made between endocrine cell number and villous structure.

Experiments were organised using hath control and irradiated groups of mice. Two time points (1 and 3 days) and three radiation doses (6, 10 and 18Gy) were employed. A simple method for endocrine cell ...


Magnetic Domain Observation Using Spin-Polarized Scanning Electron Microscopy, K. Koike, H. Matsuyama, H. Todokoro, K. Hayakawa Dec 1986

Magnetic Domain Observation Using Spin-Polarized Scanning Electron Microscopy, K. Koike, H. Matsuyama, H. Todokoro, K. Hayakawa

Scanning Microscopy

A new apparatus, spin-polarized scanning electron microscope (SEM), has been developed. This is a unique apparatus, which forms images by electron spin polarization. By using this device, magnetic domain images can be obtained because secondary electrons from ferromagnetic samples are polarized representing the magnetization of the sample originating point. This method provides new capabilities, such as magnetic contrast independent of surface morphology, detection of magnetization direction, and high spatial resolution.


The 1986 Iowa Corn Yield Test Report, District 7, K. E. Ziegler Dec 1986

The 1986 Iowa Corn Yield Test Report, District 7, K. E. Ziegler

Iowa Corn Yield Tests

Results of the Iowa Com Yield Test are published to aid Iowa farmers in selecting com varieties. This is the sixty-sixth consecutive year for the test.


Electron Beam Induced Current Analysis Of Voltage Breakdown Sites In Thin Mos Oxides, J. Reimer, A. Battacharyya, K. Ritz Dec 1986

Electron Beam Induced Current Analysis Of Voltage Breakdown Sites In Thin Mos Oxides, J. Reimer, A. Battacharyya, K. Ritz

Scanning Microscopy

Voltage breakdown sites on thin (< 100 A) MOS capacitors have been identified by the electron beam induced current (EBIC) technique, using a scanning electron microscope (SEM). EBIC spots coincide with voltage breakdown locations and their image intensity can be changed by varying the applied bias or the electron beam accelerating voltage. Total current and the number of EBIC spots were the same in both accumulation and depletion conditions for a fixed beam potential and bias voltage. This suggests that the observed EBIC spots were due to defects in the oxide only. This EBIC method for identifying defects has been found very useful in characterizing thin MOS oxides.


The 1986 Iowa Corn Yield Test Report, District 6, K. E. Ziegler Dec 1986

The 1986 Iowa Corn Yield Test Report, District 6, K. E. Ziegler

Iowa Corn Yield Tests

Results of the Iowa Com Yield Test are published to aid Iowa farmers in selecting com varieties. This is the sixty-sixth consecutive year for the test.


The 1986 Iowa Corn Yield Test Report, District 5, K. E. Ziegler Dec 1986

The 1986 Iowa Corn Yield Test Report, District 5, K. E. Ziegler

Iowa Corn Yield Tests

Results of the Iowa Com Yield Test are published to aid Iowa farmers in selecting com varieties. This is the sixty-sixth consecutive year for the test.


The 1986 Iowa Corn Yield Test Report, District 4, K. E. Ziegler Dec 1986

The 1986 Iowa Corn Yield Test Report, District 4, K. E. Ziegler

Iowa Corn Yield Tests

Results of the Iowa Com Yield Test are published to aid Iowa farmers in selecting com varieties. This is the sixty-sixth consecutive year for the test.


The 1986 Iowa Corn Yield Test Report, District 3, K. E. Ziegler Dec 1986

The 1986 Iowa Corn Yield Test Report, District 3, K. E. Ziegler

Iowa Corn Yield Tests

Results of the Iowa Com Yield Test are published to aid Iowa farmers in selecting com varieties. This is the sixty-sixth consecutive year for the test.


The 1986 Iowa Corn Yield Test Report, District 2, K. E. Ziegler Dec 1986

The 1986 Iowa Corn Yield Test Report, District 2, K. E. Ziegler

Iowa Corn Yield Tests

Results of the Iowa Com Yield Test are published to aid Iowa farmers in selecting com varieties. This is the sixty-sixth consecutive year for the test.


Time-Dependent Appearance Of Polyphenol Oxidase: A Possible Mechanism Explaining The Bimodal Growth Response Of The Wood-Decay Fungus Coriolus Versicolor To Polyphenol In Culture, Rosannah Taylor Dec 1986

Time-Dependent Appearance Of Polyphenol Oxidase: A Possible Mechanism Explaining The Bimodal Growth Response Of The Wood-Decay Fungus Coriolus Versicolor To Polyphenol In Culture, Rosannah Taylor

ETD Collection for AUC Robert W. Woodruff Library

No abstract provided.


Cassin’S Sparrow In Garden County, Thomas E. Labedz Dec 1986

Cassin’S Sparrow In Garden County, Thomas E. Labedz

Nebraska Bird Review

On 21 May 1986, while searching for evidence of breeding birds in atlas block 2G04 near Lisco, Garden County, Nebraska, I discovered a Cassin’s Sparrow (Aimophila cassinii). This sighting was at 5:20 PM Mountain Daylight Time, along the county road in the northeast corner of Section 11. I was driving slowly down the road and stopped to observe an odd sparrow. I nearly drove past, thinking it was another Grasshopper Sparrow (Ammodramus savannarum), which I had heard and seen all day. The sparrow, which appeared larger than a Grasshopper Sparrow, was perched on the low wire of a ...


Nebraska Bird Review (December 1986) 54(4), Whole Issue Dec 1986

Nebraska Bird Review (December 1986) 54(4), Whole Issue

Nebraska Bird Review

Sharp-tailed Sandpiper and Ivory Gull Reported … 70

“. . . On Our Nebraska Records,” Revisited … 71

By-laws of the NOU Records Committee … 72

Writing a Documentation … 74

California Gull in Keith County, Nebraska … 77

Avian Cholera in the Panhandle, 1985–1986 … 78

1986 Fall Field Day … 79

Book Reviews … 80

Cassin’s Sparrow in Garden County … 80

Notes … 81

Proximity Nesting: The Great Horned Owl and Red-tailed Hawk … 84

Index to Volume 54 … 86


California Gull In Keith County, Nebraska, Mark A. Brogie Dec 1986

California Gull In Keith County, Nebraska, Mark A. Brogie

Nebraska Bird Review

The status of the California Gull (Larus californicus) in Nebraska has undergone a series of changes in recent years. Rapp et al. (1958) makes no mention of this species for Nebraska, although one was collected 19 March 1933 in Lancaster County (Hudson 1933) and is now an axial skeleton #ZM11152 in the University of Nebraska State Museum (Bray et al. 1986). Johnsgard (1980) lists the species as an extremely rare migrant or vagrant in most of Nebraska, while Rasche (1982) designates it as casual in spring and summer and accidental in autumn in northwestern Nebraska and southwestern South Dakota. Rasche ...


“On Our Nebraska Records," Revisited, Wayne J. Mollhoff Dec 1986

“On Our Nebraska Records," Revisited, Wayne J. Mollhoff

Nebraska Bird Review

At the second annual meeting of the NOU, Dr. Robert H. Wolcott, one of our founders, presented a paper titled “On Migration Records and On Our Nebraska Records” (Proc. NOU 2:69, 1901), which included a plea for better documentation. He said, in part, “These problems must be met and answered in a spirit of scientific accuracy, if our conclusions are to carry weight with those living outside our borders. We must know what we know and record only what we know we know. We must be open at all times to conviction, but at the same time we must ...